// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Procedures for interfacing to Open Firmware.
 *
 * Paul Mackerras       August 1996.
 * Copyright (C) 1996-2005 Paul Mackerras.
 * 
 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
 *    {engebret|bergner}@us.ibm.com 
 */

#undef DEBUG_PROM

/* we cannot use FORTIFY as it brings in new symbols */
#define __NO_FORTIFY

#include <linux/stdarg.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/threads.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/initrd.h>
#include <linux/bitops.h>
#include <linux/pgtable.h>
#include <linux/printk.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/page.h>
#include <asm/processor.h>
#include <asm/interrupt.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/mmu.h>
#include <asm/iommu.h>
#include <asm/btext.h>
#include <asm/sections.h>
#include <asm/machdep.h>
#include <asm/asm-prototypes.h>
#include <asm/ultravisor-api.h>

#include <linux/linux_logo.h>

/* All of prom_init bss lives here */
#define __prombss __section(".bss.prominit")

/*
 * Eventually bump that one up
 */
#define DEVTREE_CHUNK_SIZE      0x100000

/*
 * This is the size of the local memory reserve map that gets copied
 * into the boot params passed to the kernel. That size is totally
 * flexible as the kernel just reads the list until it encounters an
 * entry with size 0, so it can be changed without breaking binary
 * compatibility
 */
#define MEM_RESERVE_MAP_SIZE    8

/*
 * prom_init() is called very early on, before the kernel text
 * and data have been mapped to KERNELBASE.  At this point the code
 * is running at whatever address it has been loaded at.
 * On ppc32 we compile with -mrelocatable, which means that references
 * to extern and static variables get relocated automatically.
 * ppc64 objects are always relocatable, we just need to relocate the
 * TOC.
 *
 * Because OF may have mapped I/O devices into the area starting at
 * KERNELBASE, particularly on CHRP machines, we can't safely call
 * OF once the kernel has been mapped to KERNELBASE.  Therefore all
 * OF calls must be done within prom_init().
 *
 * ADDR is used in calls to call_prom.  The 4th and following
 * arguments to call_prom should be 32-bit values.
 * On ppc64, 64 bit values are truncated to 32 bits (and
 * fortunately don't get interpreted as two arguments).
 */
#define ADDR(x)         (u32)(unsigned long)(x)

#ifdef CONFIG_PPC64
#define OF_WORKAROUNDS  0
#else
#define OF_WORKAROUNDS  of_workarounds
static int of_workarounds __prombss;
#endif

#define OF_WA_CLAIM     1       /* do phys/virt claim separately, then map */
#define OF_WA_LONGTRAIL 2       /* work around longtrail bugs */

#define PROM_BUG() do {                                         \
        prom_printf("kernel BUG at %s line 0x%x!\n",            \
                    __FILE__, __LINE__);                        \
        __builtin_trap();                                       \
} while (0)

#ifdef DEBUG_PROM
#define prom_debug(x...)        prom_printf(x)
#else
#define prom_debug(x...)        do { } while (0)
#endif


typedef u32 prom_arg_t;

struct prom_args {
        __be32 service;
        __be32 nargs;
        __be32 nret;
        __be32 args[10];
};

struct prom_t {
        ihandle root;
        phandle chosen;
        int cpu;
        ihandle stdout;
        ihandle mmumap;
        ihandle memory;
};

struct mem_map_entry {
        __be64  base;
        __be64  size;
};

typedef __be32 cell_t;

extern void __start(unsigned long r3, unsigned long r4, unsigned long r5,
                    unsigned long r6, unsigned long r7, unsigned long r8,
                    unsigned long r9);

#ifdef CONFIG_PPC64
extern int enter_prom(struct prom_args *args, unsigned long entry);
#else
static inline int enter_prom(struct prom_args *args, unsigned long entry)
{
        return ((int (*)(struct prom_args *))entry)(args);
}
#endif

extern void copy_and_flush(unsigned long dest, unsigned long src,
                           unsigned long size, unsigned long offset);

/* prom structure */
static struct prom_t __prombss prom;

static unsigned long __prombss prom_entry;

static char __prombss of_stdout_device[256];
static char __prombss prom_scratch[256];

static unsigned long __prombss dt_header_start;
static unsigned long __prombss dt_struct_start, dt_struct_end;
static unsigned long __prombss dt_string_start, dt_string_end;

static unsigned long __prombss prom_initrd_start, prom_initrd_end;

#ifdef CONFIG_PPC64
static int __prombss prom_iommu_force_on;
static int __prombss prom_iommu_off;
static unsigned long __prombss prom_tce_alloc_start;
static unsigned long __prombss prom_tce_alloc_end;
#endif

#ifdef CONFIG_PPC_PSERIES
static bool __prombss prom_radix_disable;
static bool __prombss prom_radix_gtse_disable;
static bool __prombss prom_xive_disable;
#endif

#ifdef CONFIG_PPC_SVM
static bool __prombss prom_svm_enable;
#endif

struct platform_support {
        bool hash_mmu;
        bool radix_mmu;
        bool radix_gtse;
        bool xive;
};

/* Platforms codes are now obsolete in the kernel. Now only used within this
 * file and ultimately gone too. Feel free to change them if you need, they
 * are not shared with anything outside of this file anymore
 */
#define PLATFORM_PSERIES        0x0100
#define PLATFORM_PSERIES_LPAR   0x0101
#define PLATFORM_LPAR           0x0001
#define PLATFORM_POWERMAC       0x0400
#define PLATFORM_GENERIC        0x0500

static int __prombss of_platform;

static char __prombss prom_cmd_line[COMMAND_LINE_SIZE];

static unsigned long __prombss prom_memory_limit;

static unsigned long __prombss alloc_top;
static unsigned long __prombss alloc_top_high;
static unsigned long __prombss alloc_bottom;
static unsigned long __prombss rmo_top;
static unsigned long __prombss ram_top;

static struct mem_map_entry __prombss mem_reserve_map[MEM_RESERVE_MAP_SIZE];
static int __prombss mem_reserve_cnt;

static cell_t __prombss regbuf[1024];

static bool  __prombss rtas_has_query_cpu_stopped;


/*
 * Error results ... some OF calls will return "-1" on error, some
 * will return 0, some will return either. To simplify, here are
 * macros to use with any ihandle or phandle return value to check if
 * it is valid
 */

#define PROM_ERROR              (-1u)
#define PHANDLE_VALID(p)        ((p) != 0 && (p) != PROM_ERROR)
#define IHANDLE_VALID(i)        ((i) != 0 && (i) != PROM_ERROR)

/* Copied from lib/string.c and lib/kstrtox.c */

static int __init prom_strcmp(const char *cs, const char *ct)
{
        unsigned char c1, c2;

        while (1) {
                c1 = *cs++;
                c2 = *ct++;
                if (c1 != c2)
                        return c1 < c2 ? -1 : 1;
                if (!c1)
                        break;
        }
        return 0;
}

static ssize_t __init prom_strscpy_pad(char *dest, const char *src, size_t n)
{
        ssize_t rc;
        size_t i;

        if (n == 0 || n > INT_MAX)
                return -E2BIG;

        // Copy up to n bytes
        for (i = 0; i < n && src[i] != '\0'; i++)
                dest[i] = src[i];

        rc = i;

        // If we copied all n then we have run out of space for the nul
        if (rc == n) {
                // Rewind by one character to ensure nul termination
                i--;
                rc = -E2BIG;
        }

        for (; i < n; i++)
                dest[i] = '\0';

        return rc;
}

static int __init prom_strncmp(const char *cs, const char *ct, size_t count)
{
        unsigned char c1, c2;

        while (count) {
                c1 = *cs++;
                c2 = *ct++;
                if (c1 != c2)
                        return c1 < c2 ? -1 : 1;
                if (!c1)
                        break;
                count--;
        }
        return 0;
}

static size_t __init prom_strlen(const char *s)
{
        const char *sc;

        for (sc = s; *sc != '\0'; ++sc)
                /* nothing */;
        return sc - s;
}

static int __init prom_memcmp(const void *cs, const void *ct, size_t count)
{
        const unsigned char *su1, *su2;
        int res = 0;

        for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
                if ((res = *su1 - *su2) != 0)
                        break;
        return res;
}

static char __init *prom_strstr(const char *s1, const char *s2)
{
        size_t l1, l2;

        l2 = prom_strlen(s2);
        if (!l2)
                return (char *)s1;
        l1 = prom_strlen(s1);
        while (l1 >= l2) {
                l1--;
                if (!prom_memcmp(s1, s2, l2))
                        return (char *)s1;
                s1++;
        }
        return NULL;
}

static size_t __init prom_strlcat(char *dest, const char *src, size_t count)
{
        size_t dsize = prom_strlen(dest);
        size_t len = prom_strlen(src);
        size_t res = dsize + len;

        /* This would be a bug */
        if (dsize >= count)
                return count;

        dest += dsize;
        count -= dsize;
        if (len >= count)
                len = count-1;
        memcpy(dest, src, len);
        dest[len] = 0;
        return res;

}

#ifdef CONFIG_PPC_PSERIES
static int __init prom_strtobool(const char *s, bool *res)
{
        if (!s)
                return -EINVAL;

        switch (s[0]) {
        case 'y':
        case 'Y':
        case '1':
                *res = true;
                return 0;
        case 'n':
        case 'N':
        case '0':
                *res = false;
                return 0;
        case 'o':
        case 'O':
                switch (s[1]) {
                case 'n':
                case 'N':
                        *res = true;
                        return 0;
                case 'f':
                case 'F':
                        *res = false;
                        return 0;
                default:
                        break;
                }
                break;
        default:
                break;
        }

        return -EINVAL;
}
#endif

/* This is the one and *ONLY* place where we actually call open
 * firmware.
 */

static int __init call_prom(const char *service, int nargs, int nret, ...)
{
        int i;
        struct prom_args args;
        va_list list;

        args.service = cpu_to_be32(ADDR(service));
        args.nargs = cpu_to_be32(nargs);
        args.nret = cpu_to_be32(nret);

        va_start(list, nret);
        for (i = 0; i < nargs; i++)
                args.args[i] = cpu_to_be32(va_arg(list, prom_arg_t));
        va_end(list);

        for (i = 0; i < nret; i++)
                args.args[nargs+i] = 0;

        if (enter_prom(&args, prom_entry) < 0)
                return PROM_ERROR;

        return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
}

static int __init call_prom_ret(const char *service, int nargs, int nret,
                                prom_arg_t *rets, ...)
{
        int i;
        struct prom_args args;
        va_list list;

        args.service = cpu_to_be32(ADDR(service));
        args.nargs = cpu_to_be32(nargs);
        args.nret = cpu_to_be32(nret);

        va_start(list, rets);
        for (i = 0; i < nargs; i++)
                args.args[i] = cpu_to_be32(va_arg(list, prom_arg_t));
        va_end(list);

        for (i = 0; i < nret; i++)
                args.args[nargs+i] = 0;

        if (enter_prom(&args, prom_entry) < 0)
                return PROM_ERROR;

        if (rets != NULL)
                for (i = 1; i < nret; ++i)
                        rets[i-1] = be32_to_cpu(args.args[nargs+i]);

        return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
}


static void __init prom_print(const char *msg)
{
        const char *p, *q;

        if (prom.stdout == 0)
                return;

        for (p = msg; *p != 0; p = q) {
                for (q = p; *q != 0 && *q != '\n'; ++q)
                        ;
                if (q > p)
                        call_prom("write", 3, 1, prom.stdout, p, q - p);
                if (*q == 0)
                        break;
                ++q;
                call_prom("write", 3, 1, prom.stdout, ADDR("\r\n"), 2);
        }
}


/*
 * Both prom_print_hex & prom_print_dec takes an unsigned long as input so that
 * we do not need __udivdi3 or __umoddi3 on 32bits.
 */
static void __init prom_print_hex(unsigned long val)
{
        int i, nibbles = sizeof(val)*2;
        char buf[sizeof(val)*2+1];

        for (i = nibbles-1;  i >= 0;  i--) {
                buf[i] = (val & 0xf) + '0';
                if (buf[i] > '9')
                        buf[i] += ('a'-'0'-10);
                val >>= 4;
        }
        buf[nibbles] = '\0';
        call_prom("write", 3, 1, prom.stdout, buf, nibbles);
}

/* max number of decimal digits in an unsigned long */
#define UL_DIGITS 21
static void __init prom_print_dec(unsigned long val)
{
        int i, size;
        char buf[UL_DIGITS+1];

        for (i = UL_DIGITS-1; i >= 0;  i--) {
                buf[i] = (val % 10) + '0';
                val = val/10;
                if (val == 0)
                        break;
        }
        /* shift stuff down */
        size = UL_DIGITS - i;
        call_prom("write", 3, 1, prom.stdout, buf+i, size);
}

__printf(1, 2)
static void __init prom_printf(const char *format, ...)
{
        const char *p, *q, *s;
        va_list args;
        unsigned long v;
        long vs;
        int n = 0;

        va_start(args, format);
        for (p = format; *p != 0; p = q) {
                for (q = p; *q != 0 && *q != '\n' && *q != '%'; ++q)
                        ;
                if (q > p)
                        call_prom("write", 3, 1, prom.stdout, p, q - p);
                if (*q == 0)
                        break;
                if (*q == '\n') {
                        ++q;
                        call_prom("write", 3, 1, prom.stdout,
                                  ADDR("\r\n"), 2);
                        continue;
                }
                ++q;
                if (*q == 0)
                        break;
                while (*q == 'l') {
                        ++q;
                        ++n;
                }
                switch (*q) {
                case 's':
                        ++q;
                        s = va_arg(args, const char *);
                        prom_print(s);
                        break;
                case 'x':
                        ++q;
                        switch (n) {
                        case 0:
                                v = va_arg(args, unsigned int);
                                break;
                        case 1:
                                v = va_arg(args, unsigned long);
                                break;
                        case 2:
                        default:
                                v = va_arg(args, unsigned long long);
                                break;
                        }
                        prom_print_hex(v);
                        break;
                case 'u':
                        ++q;
                        switch (n) {
                        case 0:
                                v = va_arg(args, unsigned int);
                                break;
                        case 1:
                                v = va_arg(args, unsigned long);
                                break;
                        case 2:
                        default:
                                v = va_arg(args, unsigned long long);
                                break;
                        }
                        prom_print_dec(v);
                        break;
                case 'd':
                        ++q;
                        switch (n) {
                        case 0:
                                vs = va_arg(args, int);
                                break;
                        case 1:
                                vs = va_arg(args, long);
                                break;
                        case 2:
                        default:
                                vs = va_arg(args, long long);
                                break;
                        }
                        if (vs < 0) {
                                prom_print("-");
                                vs = -vs;
                        }
                        prom_print_dec(vs);
                        break;
                }
        }
        va_end(args);
}


static unsigned int __init prom_claim(unsigned long virt, unsigned long size,
                                unsigned long align)
{

        if (align == 0 && (OF_WORKAROUNDS & OF_WA_CLAIM)) {
                /*
                 * Old OF requires we claim physical and virtual separately
                 * and then map explicitly (assuming virtual mode)
                 */
                int ret;
                prom_arg_t result;

                ret = call_prom_ret("call-method", 5, 2, &result,
                                    ADDR("claim"), prom.memory,
                                    align, size, virt);
                if (ret != 0 || result == -1)
                        return -1;
                ret = call_prom_ret("call-method", 5, 2, &result,
                                    ADDR("claim"), prom.mmumap,
                                    align, size, virt);
                if (ret != 0) {
                        call_prom("call-method", 4, 1, ADDR("release"),
                                  prom.memory, size, virt);
                        return -1;
                }
                /* the 0x12 is M (coherence) + PP == read/write */
                call_prom("call-method", 6, 1,
                          ADDR("map"), prom.mmumap, 0x12, size, virt, virt);
                return virt;
        }
        return call_prom("claim", 3, 1, (prom_arg_t)virt, (prom_arg_t)size,
                         (prom_arg_t)align);
}

static void __init __attribute__((noreturn)) prom_panic(const char *reason)
{
        prom_print(reason);
        /* Do not call exit because it clears the screen on pmac
         * it also causes some sort of double-fault on early pmacs */
        if (of_platform == PLATFORM_POWERMAC)
                asm("trap\n");

        /* ToDo: should put up an SRC here on pSeries */
        call_prom("exit", 0, 0);

        for (;;)                        /* should never get here */
                ;
}


static int __init prom_next_node(phandle *nodep)
{
        phandle node;

        if ((node = *nodep) != 0
            && (*nodep = call_prom("child", 1, 1, node)) != 0)
                return 1;
        if ((*nodep = call_prom("peer", 1, 1, node)) != 0)
                return 1;
        for (;;) {
                if ((node = call_prom("parent", 1, 1, node)) == 0)
                        return 0;
                if ((*nodep = call_prom("peer", 1, 1, node)) != 0)
                        return 1;
        }
}

static inline int __init prom_getprop(phandle node, const char *pname,
                                      void *value, size_t valuelen)
{
        return call_prom("getprop", 4, 1, node, ADDR(pname),
                         (u32)(unsigned long) value, (u32) valuelen);
}

static inline int __init prom_getproplen(phandle node, const char *pname)
{
        return call_prom("getproplen", 2, 1, node, ADDR(pname));
}

static void add_string(char **str, const char *q)
{
        char *p = *str;

        while (*q)
                *p++ = *q++;
        *p++ = ' ';
        *str = p;
}

static char *tohex(unsigned int x)
{
        static const char digits[] __initconst = "0123456789abcdef";
        static char result[9] __prombss;
        int i;

        result[8] = 0;
        i = 8;
        do {
                --i;
                result[i] = digits[x & 0xf];
                x >>= 4;
        } while (x != 0 && i > 0);
        return &result[i];
}

static int __init prom_setprop(phandle node, const char *nodename,
                               const char *pname, void *value, size_t valuelen)
{
        char cmd[256], *p;

        if (!(OF_WORKAROUNDS & OF_WA_LONGTRAIL))
                return call_prom("setprop", 4, 1, node, ADDR(pname),
                                 (u32)(unsigned long) value, (u32) valuelen);

        /* gah... setprop doesn't work on longtrail, have to use interpret */
        p = cmd;
        add_string(&p, "dev");
        add_string(&p, nodename);
        add_string(&p, tohex((u32)(unsigned long) value));
        add_string(&p, tohex(valuelen));
        add_string(&p, tohex(ADDR(pname)));
        add_string(&p, tohex(prom_strlen(pname)));
        add_string(&p, "property");
        *p = 0;
        return call_prom("interpret", 1, 1, (u32)(unsigned long) cmd);
}

/* We can't use the standard versions because of relocation headaches. */
#define prom_isxdigit(c) \
        (('0' <= (c) && (c) <= '9') || ('a' <= (c) && (c) <= 'f') || ('A' <= (c) && (c) <= 'F'))

#define prom_isdigit(c) ('0' <= (c) && (c) <= '9')
#define prom_islower(c) ('a' <= (c) && (c) <= 'z')
#define prom_toupper(c) (prom_islower(c) ? ((c) - 'a' + 'A') : (c))

static unsigned long prom_strtoul(const char *cp, const char **endp)
{
        unsigned long result = 0, base = 10, value;

        if (*cp == '0') {
                base = 8;
                cp++;
                if (prom_toupper(*cp) == 'X') {
                        cp++;
                        base = 16;
                }
        }

        while (prom_isxdigit(*cp) &&
               (value = prom_isdigit(*cp) ? *cp - '0' : prom_toupper(*cp) - 'A' + 10) < base) {
                result = result * base + value;
                cp++;
        }

        if (endp)
                *endp = cp;

        return result;
}

static unsigned long prom_memparse(const char *ptr, const char **retptr)
{
        unsigned long ret = prom_strtoul(ptr, retptr);
        int shift = 0;

        /*
         * We can't use a switch here because GCC *may* generate a
         * jump table which won't work, because we're not running at
         * the address we're linked at.
         */
        if ('G' == **retptr || 'g' == **retptr)
                shift = 30;

        if ('M' == **retptr || 'm' == **retptr)
                shift = 20;

        if ('K' == **retptr || 'k' == **retptr)
                shift = 10;

        if (shift) {
                ret <<= shift;
                (*retptr)++;
        }

        return ret;
}

/*
 * Early parsing of the command line passed to the kernel, used for
 * "mem=x" and the options that affect the iommu
 */
static void __init early_cmdline_parse(void)
{
        const char *opt;

        char *p;
        int l = 0;

        prom_cmd_line[0] = 0;
        p = prom_cmd_line;

        if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && (long)prom.chosen > 0)
                l = prom_getprop(prom.chosen, "bootargs", p, COMMAND_LINE_SIZE-1);

        if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) || l <= 0 || p[0] == '\0')
                prom_strlcat(prom_cmd_line, " " CONFIG_CMDLINE,
                             sizeof(prom_cmd_line));

        prom_printf("command line: %s\n", prom_cmd_line);

#ifdef CONFIG_PPC64
        opt = prom_strstr(prom_cmd_line, "iommu=");
        if (opt) {
                prom_printf("iommu opt is: %s\n", opt);
                opt += 6;
                while (*opt && *opt == ' ')
                        opt++;
                if (!prom_strncmp(opt, "off", 3))
                        prom_iommu_off = 1;
                else if (!prom_strncmp(opt, "force", 5))
                        prom_iommu_force_on = 1;
        }
#endif
        opt = prom_strstr(prom_cmd_line, "mem=");
        if (opt) {
                opt += 4;
                prom_memory_limit = prom_memparse(opt, (const char **)&opt);
#ifdef CONFIG_PPC64
                /* Align to 16 MB == size of ppc64 large page */
                prom_memory_limit = ALIGN(prom_memory_limit, 0x1000000);
#endif
        }

#ifdef CONFIG_PPC_PSERIES
        prom_radix_disable = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT);
        opt = prom_strstr(prom_cmd_line, "disable_radix");
        if (opt) {
                opt += 13;
                if (*opt && *opt == '=') {
                        bool val;

                        if (prom_strtobool(++opt, &val))
                                prom_radix_disable = false;
                        else
                                prom_radix_disable = val;
                } else
                        prom_radix_disable = true;
        }
        if (prom_radix_disable)
                prom_debug("Radix disabled from cmdline\n");

        opt = prom_strstr(prom_cmd_line, "radix_hcall_invalidate=on");
        if (opt) {
                prom_radix_gtse_disable = true;
                prom_debug("Radix GTSE disabled from cmdline\n");
        }

        opt = prom_strstr(prom_cmd_line, "xive=off");
        if (opt) {
                prom_xive_disable = true;
                prom_debug("XIVE disabled from cmdline\n");
        }
#endif /* CONFIG_PPC_PSERIES */

#ifdef CONFIG_PPC_SVM
        opt = prom_strstr(prom_cmd_line, "svm=");
        if (opt) {
                bool val;

                opt += sizeof("svm=") - 1;
                if (!prom_strtobool(opt, &val))
                        prom_svm_enable = val;
        }
#endif /* CONFIG_PPC_SVM */
}

#ifdef CONFIG_PPC_PSERIES
/*
 * The architecture vector has an array of PVR mask/value pairs,
 * followed by # option vectors - 1, followed by the option vectors.
 *
 * See prom.h for the definition of the bits specified in the
 * architecture vector.
 */

/* Firmware expects the value to be n - 1, where n is the # of vectors */
#define NUM_VECTORS(n)          ((n) - 1)

/*
 * Firmware expects 1 + n - 2, where n is the length of the option vector in
 * bytes. The 1 accounts for the length byte itself, the - 2 .. ?
 */
#define VECTOR_LENGTH(n)        (1 + (n) - 2)

struct option_vector1 {
        u8 byte1;
        u8 arch_versions;
        u8 arch_versions3;
} __packed;

struct option_vector2 {
        u8 byte1;
        __be16 reserved;
        __be32 real_base;
        __be32 real_size;
        __be32 virt_base;
        __be32 virt_size;
        __be32 load_base;
        __be32 min_rma;
        __be32 min_load;
        u8 min_rma_percent;
        u8 max_pft_size;
} __packed;

struct option_vector3 {
        u8 byte1;
        u8 byte2;
} __packed;

struct option_vector4 {
        u8 byte1;
        u8 min_vp_cap;
} __packed;

struct option_vector5 {
        u8 byte1;
        u8 byte2;
        u8 byte3;
        u8 cmo;
        u8 associativity;
        u8 bin_opts;
        u8 micro_checkpoint;
        u8 reserved0;
        __be32 max_cpus;
        __be16 papr_level;
        __be16 reserved1;
        u8 platform_facilities;
        u8 reserved2;
        __be16 reserved3;
        u8 subprocessors;
        u8 byte22;
        u8 intarch;
        u8 mmu;
        u8 hash_ext;
        u8 radix_ext;
} __packed;

struct option_vector6 {
        u8 reserved;
        u8 secondary_pteg;
        u8 os_name;
} __packed;

struct option_vector7 {
        u8 os_id[256];
} __packed;

struct ibm_arch_vec {
        struct { u32 mask, val; } pvrs[14];

        u8 num_vectors;

        u8 vec1_len;
        struct option_vector1 vec1;

        u8 vec2_len;
        struct option_vector2 vec2;

        u8 vec3_len;
        struct option_vector3 vec3;

        u8 vec4_len;
        struct option_vector4 vec4;

        u8 vec5_len;
        struct option_vector5 vec5;

        u8 vec6_len;
        struct option_vector6 vec6;

        u8 vec7_len;
        struct option_vector7 vec7;
} __packed;

static const struct ibm_arch_vec ibm_architecture_vec_template __initconst = {
        .pvrs = {
                {
                        .mask = cpu_to_be32(0xfffe0000), /* POWER5/POWER5+ */
                        .val  = cpu_to_be32(0x003a0000),
                },
                {
                        .mask = cpu_to_be32(0xffff0000), /* POWER6 */
                        .val  = cpu_to_be32(0x003e0000),
                },
                {
                        .mask = cpu_to_be32(0xffff0000), /* POWER7 */
                        .val  = cpu_to_be32(0x003f0000),
                },
                {
                        .mask = cpu_to_be32(0xffff0000), /* POWER8E */
                        .val  = cpu_to_be32(0x004b0000),
                },
                {
                        .mask = cpu_to_be32(0xffff0000), /* POWER8NVL */
                        .val  = cpu_to_be32(0x004c0000),

                },
                {
                        .mask = cpu_to_be32(0xffff0000), /* POWER8 */
                        .val  = cpu_to_be32(0x004d0000),
                },
                {
                        .mask = cpu_to_be32(0xffff0000), /* POWER9 */
                        .val  = cpu_to_be32(0x004e0000),
                },
                {
                        .mask = cpu_to_be32(0xffff0000), /* POWER10 */
                        .val  = cpu_to_be32(0x00800000),
                },
                {
                        .mask = cpu_to_be32(0xffffffff), /* all 3.1-compliant */
                        .val  = cpu_to_be32(0x0f000006),
                },
                {
                        .mask = cpu_to_be32(0xffffffff), /* all 3.00-compliant */
                        .val  = cpu_to_be32(0x0f000005),
                },
                {
                        .mask = cpu_to_be32(0xffffffff), /* all 2.07-compliant */
                        .val  = cpu_to_be32(0x0f000004),
                },
                {
                        .mask = cpu_to_be32(0xffffffff), /* all 2.06-compliant */
                        .val  = cpu_to_be32(0x0f000003),
                },
                {
                        .mask = cpu_to_be32(0xffffffff), /* all 2.05-compliant */
                        .val  = cpu_to_be32(0x0f000002),
                },
                {
                        .mask = cpu_to_be32(0xfffffffe), /* all 2.04-compliant and earlier */
                        .val  = cpu_to_be32(0x0f000001),
                },
        },

        .num_vectors = NUM_VECTORS(6),

        .vec1_len = VECTOR_LENGTH(sizeof(struct option_vector1)),
        .vec1 = {
                .byte1 = 0,
                .arch_versions = OV1_PPC_2_00 | OV1_PPC_2_01 | OV1_PPC_2_02 | OV1_PPC_2_03 |
                                 OV1_PPC_2_04 | OV1_PPC_2_05 | OV1_PPC_2_06 | OV1_PPC_2_07,
                .arch_versions3 = OV1_PPC_3_00 | OV1_PPC_3_1,
        },

        .vec2_len = VECTOR_LENGTH(sizeof(struct option_vector2)),
        /* option vector 2: Open Firmware options supported */
        .vec2 = {
                .byte1 = OV2_REAL_MODE,
                .reserved = 0,
                .real_base = cpu_to_be32(0xffffffff),
                .real_size = cpu_to_be32(0xffffffff),
                .virt_base = cpu_to_be32(0xffffffff),
                .virt_size = cpu_to_be32(0xffffffff),
                .load_base = cpu_to_be32(0xffffffff),
                .min_rma = cpu_to_be32(512),            /* 512MB min RMA */
                .min_load = cpu_to_be32(0xffffffff),    /* full client load */
                .min_rma_percent = 0,   /* min RMA percentage of total RAM */
                .max_pft_size = 48,     /* max log_2(hash table size) */
        },

        .vec3_len = VECTOR_LENGTH(sizeof(struct option_vector3)),
        /* option vector 3: processor options supported */
        .vec3 = {
                .byte1 = 0,                     /* don't ignore, don't halt */
                .byte2 = OV3_FP | OV3_VMX | OV3_DFP,
        },

        .vec4_len = VECTOR_LENGTH(sizeof(struct option_vector4)),
        /* option vector 4: IBM PAPR implementation */
        .vec4 = {
                .byte1 = 0,                     /* don't halt */
                .min_vp_cap = OV4_MIN_ENT_CAP,  /* minimum VP entitled capacity */
        },

        .vec5_len = VECTOR_LENGTH(sizeof(struct option_vector5)),
        /* option vector 5: PAPR/OF options */
        .vec5 = {
                .byte1 = 0,                             /* don't ignore, don't halt */
                .byte2 = OV5_FEAT(OV5_LPAR) | OV5_FEAT(OV5_SPLPAR) | OV5_FEAT(OV5_LARGE_PAGES) |
                OV5_FEAT(OV5_DRCONF_MEMORY) | OV5_FEAT(OV5_DONATE_DEDICATE_CPU) |
#ifdef CONFIG_PCI_MSI
                /* PCIe/MSI support.  Without MSI full PCIe is not supported */
                OV5_FEAT(OV5_MSI),
#else
                0,
#endif
                .byte3 = 0,
                .cmo =
#ifdef CONFIG_PPC_SMLPAR
                OV5_FEAT(OV5_CMO) | OV5_FEAT(OV5_XCMO),
#else
                0,
#endif
                .associativity = OV5_FEAT(OV5_FORM1_AFFINITY) | OV5_FEAT(OV5_PRRN) |
                OV5_FEAT(OV5_FORM2_AFFINITY),
                .bin_opts = OV5_FEAT(OV5_RESIZE_HPT) | OV5_FEAT(OV5_HP_EVT),
                .micro_checkpoint = 0,
                .reserved0 = 0,
                .max_cpus = cpu_to_be32(NR_CPUS),       /* number of cores supported */
                .papr_level = 0,
                .reserved1 = 0,
                .platform_facilities = OV5_FEAT(OV5_PFO_HW_RNG) | OV5_FEAT(OV5_PFO_HW_ENCR) | OV5_FEAT(OV5_PFO_HW_842),
                .reserved2 = 0,
                .reserved3 = 0,
                .subprocessors = 1,
                .byte22 = OV5_FEAT(OV5_DRMEM_V2) | OV5_FEAT(OV5_DRC_INFO),
                .intarch = 0,
                .mmu = 0,
                .hash_ext = 0,
                .radix_ext = 0,
        },

        /* option vector 6: IBM PAPR hints */
        .vec6_len = VECTOR_LENGTH(sizeof(struct option_vector6)),
        .vec6 = {
                .reserved = 0,
                .secondary_pteg = 0,
                .os_name = OV6_LINUX,
        },

        /* option vector 7: OS Identification */
        .vec7_len = VECTOR_LENGTH(sizeof(struct option_vector7)),
};

static struct ibm_arch_vec __prombss ibm_architecture_vec  ____cacheline_aligned;

/* Old method - ELF header with PT_NOTE sections only works on BE */
#ifdef __BIG_ENDIAN__
static const struct fake_elf {
        Elf32_Ehdr      elfhdr;
        Elf32_Phdr      phdr[2];
        struct chrpnote {
                u32     namesz;
                u32     descsz;
                u32     type;
                char    name[8];        /* "PowerPC" */
                struct chrpdesc {
                        u32     real_mode;
                        u32     real_base;
                        u32     real_size;
                        u32     virt_base;
                        u32     virt_size;
                        u32     load_base;
                } chrpdesc;
        } chrpnote;
        struct rpanote {
                u32     namesz;
                u32     descsz;
                u32     type;
                char    name[24];       /* "IBM,RPA-Client-Config" */
                struct rpadesc {
                        u32     lpar_affinity;
                        u32     min_rmo_size;
                        u32     min_rmo_percent;
                        u32     max_pft_size;
                        u32     splpar;
                        u32     min_load;
                        u32     new_mem_def;
                        u32     ignore_me;
                } rpadesc;
        } rpanote;
} fake_elf __initconst = {
        .elfhdr = {
                .e_ident = { 0x7f, 'E', 'L', 'F',
                             ELFCLASS32, ELFDATA2MSB, EV_CURRENT },
                .e_type = ET_EXEC,      /* yeah right */
                .e_machine = EM_PPC,
                .e_version = EV_CURRENT,
                .e_phoff = offsetof(struct fake_elf, phdr),
                .e_phentsize = sizeof(Elf32_Phdr),
                .e_phnum = 2
        },
        .phdr = {
                [0] = {
                        .p_type = PT_NOTE,
                        .p_offset = offsetof(struct fake_elf, chrpnote),
                        .p_filesz = sizeof(struct chrpnote)
                }, [1] = {
                        .p_type = PT_NOTE,
                        .p_offset = offsetof(struct fake_elf, rpanote),
                        .p_filesz = sizeof(struct rpanote)
                }
        },
        .chrpnote = {
                .namesz = sizeof("PowerPC"),
                .descsz = sizeof(struct chrpdesc),
                .type = 0x1275,
                .name = "PowerPC",
                .chrpdesc = {
                        .real_mode = ~0U,       /* ~0 means "don't care" */
                        .real_base = ~0U,
                        .real_size = ~0U,
                        .virt_base = ~0U,
                        .virt_size = ~0U,
                        .load_base = ~0U
                },
        },
        .rpanote = {
                .namesz = sizeof("IBM,RPA-Client-Config"),
                .descsz = sizeof(struct rpadesc),
                .type = 0x12759999,
                .name = "IBM,RPA-Client-Config",
                .rpadesc = {
                        .lpar_affinity = 0,
                        .min_rmo_size = 64,     /* in megabytes */
                        .min_rmo_percent = 0,
                        .max_pft_size = 48,     /* 2^48 bytes max PFT size */
                        .splpar = 1,
                        .min_load = ~0U,
                        .new_mem_def = 0
                }
        }
};
#endif /* __BIG_ENDIAN__ */

static int __init prom_count_smt_threads(void)
{
        phandle node;
        char type[64];
        unsigned int plen;

        /* Pick up th first CPU node we can find */
        for (node = 0; prom_next_node(&node); ) {
                type[0] = 0;
                prom_getprop(node, "device_type", type, sizeof(type));

                if (prom_strcmp(type, "cpu"))
                        continue;
                /*
                 * There is an entry for each smt thread, each entry being
                 * 4 bytes long.  All cpus should have the same number of
                 * smt threads, so return after finding the first.
                 */
                plen = prom_getproplen(node, "ibm,ppc-interrupt-server#s");
                if (plen == PROM_ERROR)
                        break;
                plen >>= 2;
                prom_debug("Found %lu smt threads per core\n", (unsigned long)plen);

                /* Sanity check */
                if (plen < 1 || plen > 64) {
                        prom_printf("Threads per core %lu out of bounds, assuming 1\n",
                                    (unsigned long)plen);
                        return 1;
                }
                return plen;
        }
        prom_debug("No threads found, assuming 1 per core\n");

        return 1;

}

static void __init prom_parse_mmu_model(u8 val,
                                        struct platform_support *support)
{
        switch (val) {
        case OV5_FEAT(OV5_MMU_DYNAMIC):
        case OV5_FEAT(OV5_MMU_EITHER): /* Either Available */
                prom_debug("MMU - either supported\n");
                support->radix_mmu = !prom_radix_disable;
                support->hash_mmu = true;
                break;
        case OV5_FEAT(OV5_MMU_RADIX): /* Only Radix */
                prom_debug("MMU - radix only\n");
                if (prom_radix_disable) {
                        /*
                         * If we __have__ to do radix, we're better off ignoring
                         * the command line rather than not booting.
                         */
                        prom_printf("WARNING: Ignoring cmdline option disable_radix\n");
                }
                support->radix_mmu = true;
                break;
        case OV5_FEAT(OV5_MMU_HASH):
                prom_debug("MMU - hash only\n");
                support->hash_mmu = true;
                break;
        default:
                prom_debug("Unknown mmu support option: 0x%x\n", val);
                break;
        }
}

static void __init prom_parse_xive_model(u8 val,
                                         struct platform_support *support)
{
        switch (val) {
        case OV5_FEAT(OV5_XIVE_EITHER): /* Either Available */
                prom_debug("XIVE - either mode supported\n");
                support->xive = !prom_xive_disable;
                break;
        case OV5_FEAT(OV5_XIVE_EXPLOIT): /* Only Exploitation mode */
                prom_debug("XIVE - exploitation mode supported\n");
                if (prom_xive_disable) {
                        /*
                         * If we __have__ to do XIVE, we're better off ignoring
                         * the command line rather than not booting.
                         */
                        prom_printf("WARNING: Ignoring cmdline option xive=off\n");
                }
                support->xive = true;
                break;
        case OV5_FEAT(OV5_XIVE_LEGACY): /* Only Legacy mode */
                prom_debug("XIVE - legacy mode supported\n");
                break;
        default:
                prom_debug("Unknown xive support option: 0x%x\n", val);
                break;
        }
}

static void __init prom_parse_platform_support(u8 index, u8 val,
                                               struct platform_support *support)
{
        switch (index) {
        case OV5_INDX(OV5_MMU_SUPPORT): /* MMU Model */
                prom_parse_mmu_model(val & OV5_FEAT(OV5_MMU_SUPPORT), support);
                break;
        case OV5_INDX(OV5_RADIX_GTSE): /* Radix Extensions */
                if (val & OV5_FEAT(OV5_RADIX_GTSE))
                        support->radix_gtse = !prom_radix_gtse_disable;
                break;
        case OV5_INDX(OV5_XIVE_SUPPORT): /* Interrupt mode */
                prom_parse_xive_model(val & OV5_FEAT(OV5_XIVE_SUPPORT),
                                      support);
                break;
        }
}

static void __init prom_check_platform_support(void)
{
        struct platform_support supported = {
                .hash_mmu = false,
                .radix_mmu = false,
                .radix_gtse = false,
                .xive = false
        };
        int prop_len = prom_getproplen(prom.chosen,
                                       "ibm,arch-vec-5-platform-support");

        /*
         * First copy the architecture vec template
         *
         * use memcpy() instead of *vec = *vec_template so that GCC replaces it
         * by __memcpy() when KASAN is active
         */
        memcpy(&ibm_architecture_vec, &ibm_architecture_vec_template,
               sizeof(ibm_architecture_vec));

        prom_strscpy_pad(ibm_architecture_vec.vec7.os_id, linux_banner, 256);

        if (prop_len > 1) {
                int i;
                u8 vec[8];
                prom_debug("Found ibm,arch-vec-5-platform-support, len: %d\n",
                           prop_len);
                if (prop_len > sizeof(vec))
                        prom_printf("WARNING: ibm,arch-vec-5-platform-support longer than expected (len: %d)\n",
                                    prop_len);
                prom_getprop(prom.chosen, "ibm,arch-vec-5-platform-support", &vec, sizeof(vec));
                for (i = 0; i < prop_len; i += 2) {
                        prom_debug("%d: index = 0x%x val = 0x%x\n", i / 2, vec[i], vec[i + 1]);
                        prom_parse_platform_support(vec[i], vec[i + 1], &supported);
                }
        }

        if (supported.radix_mmu && IS_ENABLED(CONFIG_PPC_RADIX_MMU)) {
                /* Radix preferred - Check if GTSE is also supported */
                prom_debug("Asking for radix\n");
                ibm_architecture_vec.vec5.mmu = OV5_FEAT(OV5_MMU_RADIX);
                if (supported.radix_gtse)
                        ibm_architecture_vec.vec5.radix_ext =
                                        OV5_FEAT(OV5_RADIX_GTSE);
                else
                        prom_debug("Radix GTSE isn't supported\n");
        } else if (supported.hash_mmu) {
                /* Default to hash mmu (if we can) */
                prom_debug("Asking for hash\n");
                ibm_architecture_vec.vec5.mmu = OV5_FEAT(OV5_MMU_HASH);
        } else {
                /* We're probably on a legacy hypervisor */
                prom_debug("Assuming legacy hash support\n");
        }

        if (supported.xive) {
                prom_debug("Asking for XIVE\n");
                ibm_architecture_vec.vec5.intarch = OV5_FEAT(OV5_XIVE_EXPLOIT);
        }
}

static void __init prom_send_capabilities(void)
{
        ihandle root;
        prom_arg_t ret;
        u32 cores;

        /* Check ibm,arch-vec-5-platform-support and fixup vec5 if required */
        prom_check_platform_support();

        root = call_prom("open", 1, 1, ADDR("/"));
        if (root != 0) {
                /* We need to tell the FW about the number of cores we support.
                 *
                 * To do that, we count the number of threads on the first core
                 * (we assume this is the same for all cores) and use it to
                 * divide NR_CPUS.
                 */

                cores = DIV_ROUND_UP(NR_CPUS, prom_count_smt_threads());
                prom_printf("Max number of cores passed to firmware: %u (NR_CPUS = %d)\n",
                            cores, NR_CPUS);

                ibm_architecture_vec.vec5.max_cpus = cpu_to_be32(cores);

                /* try calling the ibm,client-architecture-support method */
                prom_printf("Calling ibm,client-architecture-support...");
                if (call_prom_ret("call-method", 3, 2, &ret,
                                  ADDR("ibm,client-architecture-support"),
                                  root,
                                  ADDR(&ibm_architecture_vec)) == 0) {
                        /* the call exists... */
                        if (ret)
                                prom_printf("\nWARNING: ibm,client-architecture"
                                            "-support call FAILED!\n");
                        call_prom("close", 1, 0, root);
                        prom_printf(" done\n");
                        return;
                }
                call_prom("close", 1, 0, root);
                prom_printf(" not implemented\n");
        }

#ifdef __BIG_ENDIAN__
        {
                ihandle elfloader;

                /* no ibm,client-architecture-support call, try the old way */
                elfloader = call_prom("open", 1, 1,
                                      ADDR("/packages/elf-loader"));
                if (elfloader == 0) {
                        prom_printf("couldn't open /packages/elf-loader\n");
                        return;
                }
                call_prom("call-method", 3, 1, ADDR("process-elf-header"),
                          elfloader, ADDR(&fake_elf));
                call_prom("close", 1, 0, elfloader);
        }
#endif /* __BIG_ENDIAN__ */
}
#endif /* CONFIG_PPC_PSERIES */

/*
 * Memory allocation strategy... our layout is normally:
 *
 *  at 14Mb or more we have vmlinux, then a gap and initrd.  In some
 *  rare cases, initrd might end up being before the kernel though.
 *  We assume this won't override the final kernel at 0, we have no
 *  provision to handle that in this version, but it should hopefully
 *  never happen.
 *
 *  alloc_top is set to the top of RMO, eventually shrink down if the
 *  TCEs overlap
 *
 *  alloc_bottom is set to the top of kernel/initrd
 *
 *  from there, allocations are done this way : rtas is allocated
 *  topmost, and the device-tree is allocated from the bottom. We try
 *  to grow the device-tree allocation as we progress. If we can't,
 *  then we fail, we don't currently have a facility to restart
 *  elsewhere, but that shouldn't be necessary.
 *
 *  Note that calls to reserve_mem have to be done explicitly, memory
 *  allocated with either alloc_up or alloc_down isn't automatically
 *  reserved.
 */


/*
 * Allocates memory in the RMO upward from the kernel/initrd
 *
 * When align is 0, this is a special case, it means to allocate in place
 * at the current location of alloc_bottom or fail (that is basically
 * extending the previous allocation). Used for the device-tree flattening
 */
static unsigned long __init alloc_up(unsigned long size, unsigned long align)
{
        unsigned long base = alloc_bottom;
        unsigned long addr = 0;

        if (align)
                base = ALIGN(base, align);
        prom_debug("%s(%lx, %lx)\n", __func__, size, align);
        if (ram_top == 0)
                prom_panic("alloc_up() called with mem not initialized\n");

        if (align)
                base = ALIGN(alloc_bottom, align);
        else
                base = alloc_bottom;

        for(; (base + size) <= alloc_top; 
            base = ALIGN(base + 0x100000, align)) {
                prom_debug("    trying: 0x%lx\n\r", base);
                addr = (unsigned long)prom_claim(base, size, 0);
                if (addr != PROM_ERROR && addr != 0)
                        break;
                addr = 0;
                if (align == 0)
                        break;
        }
        if (addr == 0)
                return 0;
        alloc_bottom = addr + size;

        prom_debug(" -> %lx\n", addr);
        prom_debug("  alloc_bottom : %lx\n", alloc_bottom);
        prom_debug("  alloc_top    : %lx\n", alloc_top);
        prom_debug("  alloc_top_hi : %lx\n", alloc_top_high);
        prom_debug("  rmo_top      : %lx\n", rmo_top);
        prom_debug("  ram_top      : %lx\n", ram_top);

        return addr;
}

/*
 * Allocates memory downward, either from top of RMO, or if highmem
 * is set, from the top of RAM.  Note that this one doesn't handle
 * failures.  It does claim memory if highmem is not set.
 */
static unsigned long __init alloc_down(unsigned long size, unsigned long align,
                                       int highmem)
{
        unsigned long base, addr = 0;

        prom_debug("%s(%lx, %lx, %s)\n", __func__, size, align,
                   highmem ? "(high)" : "(low)");
        if (ram_top == 0)
                prom_panic("alloc_down() called with mem not initialized\n");

        if (highmem) {
                /* Carve out storage for the TCE table. */
                addr = ALIGN_DOWN(alloc_top_high - size, align);
                if (addr <= alloc_bottom)
                        return 0;
                /* Will we bump into the RMO ? If yes, check out that we
                 * didn't overlap existing allocations there, if we did,
                 * we are dead, we must be the first in town !
                 */
                if (addr < rmo_top) {
                        /* Good, we are first */
                        if (alloc_top == rmo_top)
                                alloc_top = rmo_top = addr;
                        else
                                return 0;
                }
                alloc_top_high = addr;
                goto bail;
        }

        base = ALIGN_DOWN(alloc_top - size, align);
        for (; base > alloc_bottom;
             base = ALIGN_DOWN(base - 0x100000, align))  {
                prom_debug("    trying: 0x%lx\n\r", base);
                addr = (unsigned long)prom_claim(base, size, 0);
                if (addr != PROM_ERROR && addr != 0)
                        break;
                addr = 0;
        }
        if (addr == 0)
                return 0;
        alloc_top = addr;

 bail:
        prom_debug(" -> %lx\n", addr);
        prom_debug("  alloc_bottom : %lx\n", alloc_bottom);
        prom_debug("  alloc_top    : %lx\n", alloc_top);
        prom_debug("  alloc_top_hi : %lx\n", alloc_top_high);
        prom_debug("  rmo_top      : %lx\n", rmo_top);
        prom_debug("  ram_top      : %lx\n", ram_top);

        return addr;
}

/*
 * Parse a "reg" cell
 */
static unsigned long __init prom_next_cell(int s, cell_t **cellp)
{
        cell_t *p = *cellp;
        unsigned long r = 0;

        /* Ignore more than 2 cells */
        while (s > sizeof(unsigned long) / 4) {
                p++;
                s--;
        }
        r = be32_to_cpu(*p++);
#ifdef CONFIG_PPC64
        if (s > 1) {
                r <<= 32;
                r |= be32_to_cpu(*(p++));
        }
#endif
        *cellp = p;
        return r;
}

/*
 * Very dumb function for adding to the memory reserve list, but
 * we don't need anything smarter at this point
 *
 * XXX Eventually check for collisions.  They should NEVER happen.
 * If problems seem to show up, it would be a good start to track
 * them down.
 */
static void __init reserve_mem(u64 base, u64 size)
{
        u64 top = base + size;
        unsigned long cnt = mem_reserve_cnt;

        if (size == 0)
                return;

        /* We need to always keep one empty entry so that we
         * have our terminator with "size" set to 0 since we are
         * dumb and just copy this entire array to the boot params
         */
        base = ALIGN_DOWN(base, PAGE_SIZE);
        top = ALIGN(top, PAGE_SIZE);
        size = top - base;

        if (cnt >= (MEM_RESERVE_MAP_SIZE - 1))
                prom_panic("Memory reserve map exhausted !\n");
        mem_reserve_map[cnt].base = cpu_to_be64(base);
        mem_reserve_map[cnt].size = cpu_to_be64(size);
        mem_reserve_cnt = cnt + 1;
}

/*
 * Initialize memory allocation mechanism, parse "memory" nodes and
 * obtain that way the top of memory and RMO to setup out local allocator
 */
static void __init prom_init_mem(void)
{
        phandle node;
        char type[64];
        unsigned int plen;
        cell_t *p, *endp;
        __be32 val;
        u32 rac, rsc;

        /*
         * We iterate the memory nodes to find
         * 1) top of RMO (first node)
         * 2) top of memory
         */
        val = cpu_to_be32(2);
        prom_getprop(prom.root, "#address-cells", &val, sizeof(val));
        rac = be32_to_cpu(val);
        val = cpu_to_be32(1);
        prom_getprop(prom.root, "#size-cells", &val, sizeof(rsc));
        rsc = be32_to_cpu(val);
        prom_debug("root_addr_cells: %x\n", rac);
        prom_debug("root_size_cells: %x\n", rsc);

        prom_debug("scanning memory:\n");

        for (node = 0; prom_next_node(&node); ) {
                type[0] = 0;
                prom_getprop(node, "device_type", type, sizeof(type));

                if (type[0] == 0) {
                        /*
                         * CHRP Longtrail machines have no device_type
                         * on the memory node, so check the name instead...
                         */
                        prom_getprop(node, "name", type, sizeof(type));
                }
                if (prom_strcmp(type, "memory"))
                        continue;

                plen = prom_getprop(node, "reg", regbuf, sizeof(regbuf));
                if (plen > sizeof(regbuf)) {
                        prom_printf("memory node too large for buffer !\n");
                        plen = sizeof(regbuf);
                }
                p = regbuf;
                endp = p + (plen / sizeof(cell_t));

#ifdef DEBUG_PROM
                memset(prom_scratch, 0, sizeof(prom_scratch));
                call_prom("package-to-path", 3, 1, node, prom_scratch,
                          sizeof(prom_scratch) - 1);
                prom_debug("  node %s :\n", prom_scratch);
#endif /* DEBUG_PROM */

                while ((endp - p) >= (rac + rsc)) {
                        unsigned long base, size;

                        base = prom_next_cell(rac, &p);
                        size = prom_next_cell(rsc, &p);

                        if (size == 0)
                                continue;
                        prom_debug("    %lx %lx\n", base, size);
                        if (base == 0 && (of_platform & PLATFORM_LPAR))
                                rmo_top = size;
                        if ((base + size) > ram_top)
                                ram_top = base + size;
                }
        }

        alloc_bottom = PAGE_ALIGN((unsigned long)&_end + 0x4000);

        /*
         * If prom_memory_limit is set we reduce the upper limits *except* for
         * alloc_top_high. This must be the real top of RAM so we can put
         * TCE's up there.
         */

        alloc_top_high = ram_top;

        if (prom_memory_limit) {
                if (prom_memory_limit <= alloc_bottom) {
                        prom_printf("Ignoring mem=%lx <= alloc_bottom.\n",
                                    prom_memory_limit);
                        prom_memory_limit = 0;
                } else if (prom_memory_limit >= ram_top) {
                        prom_printf("Ignoring mem=%lx >= ram_top.\n",
                                    prom_memory_limit);
                        prom_memory_limit = 0;
                } else {
                        ram_top = prom_memory_limit;
                        rmo_top = min(rmo_top, prom_memory_limit);
                }
        }

        /*
         * Setup our top alloc point, that is top of RMO or top of
         * segment 0 when running non-LPAR.
         * Some RS64 machines have buggy firmware where claims up at
         * 1GB fail.  Cap at 768MB as a workaround.
         * Since 768MB is plenty of room, and we need to cap to something
         * reasonable on 32-bit, cap at 768MB on all machines.
         */
        if (!rmo_top)
                rmo_top = ram_top;
        rmo_top = min(0x30000000ul, rmo_top);
        alloc_top = rmo_top;
        alloc_top_high = ram_top;

        /*
         * Check if we have an initrd after the kernel but still inside
         * the RMO.  If we do move our bottom point to after it.
         */
        if (prom_initrd_start &&
            prom_initrd_start < rmo_top &&
            prom_initrd_end > alloc_bottom)
                alloc_bottom = PAGE_ALIGN(prom_initrd_end);

        prom_printf("memory layout at init:\n");
        prom_printf("  memory_limit : %lx (16 MB aligned)\n",
                    prom_memory_limit);
        prom_printf("  alloc_bottom : %lx\n", alloc_bottom);
        prom_printf("  alloc_top    : %lx\n", alloc_top);
        prom_printf("  alloc_top_hi : %lx\n", alloc_top_high);
        prom_printf("  rmo_top      : %lx\n", rmo_top);
        prom_printf("  ram_top      : %lx\n", ram_top);
}

static void __init prom_close_stdin(void)
{
        __be32 val;
        ihandle stdin;

        if (prom_getprop(prom.chosen, "stdin", &val, sizeof(val)) > 0) {
                stdin = be32_to_cpu(val);
                call_prom("close", 1, 0, stdin);
        }
}

#ifdef CONFIG_PPC_SVM
static int prom_rtas_hcall(uint64_t args)
{
        register uint64_t arg1 asm("r3") = H_RTAS;
        register uint64_t arg2 asm("r4") = args;

        asm volatile("sc 1\n" : "=r" (arg1) :
                        "r" (arg1),
                        "r" (arg2) :);
        srr_regs_clobbered();

        return arg1;
}

static struct rtas_args __prombss os_term_args;

static void __init prom_rtas_os_term(char *str)
{
        phandle rtas_node;
        __be32 val;
        u32 token;

        prom_debug("%s: start...\n", __func__);
        rtas_node = call_prom("finddevice", 1, 1, ADDR("/rtas"));
        prom_debug("rtas_node: %x\n", rtas_node);
        if (!PHANDLE_VALID(rtas_node))
                return;

        val = 0;
        prom_getprop(rtas_node, "ibm,os-term", &val, sizeof(val));
        token = be32_to_cpu(val);
        prom_debug("ibm,os-term: %x\n", token);
        if (token == 0)
                prom_panic("Could not get token for ibm,os-term\n");
        os_term_args.token = cpu_to_be32(token);
        os_term_args.nargs = cpu_to_be32(1);
        os_term_args.nret = cpu_to_be32(1);
        os_term_args.args[0] = cpu_to_be32(__pa(str));
        prom_rtas_hcall((uint64_t)&os_term_args);
}
#endif /* CONFIG_PPC_SVM */

/*
 * Allocate room for and instantiate RTAS
 */
static void __init prom_instantiate_rtas(void)
{
        phandle rtas_node;
        ihandle rtas_inst;
        u32 base, entry = 0;
        __be32 val;
        u32 size = 0;

        prom_debug("prom_instantiate_rtas: start...\n");

        rtas_node = call_prom("finddevice", 1, 1, ADDR("/rtas"));
        prom_debug("rtas_node: %x\n", rtas_node);
        if (!PHANDLE_VALID(rtas_node))
                return;

        val = 0;
        prom_getprop(rtas_node, "rtas-size", &val, sizeof(size));
        size = be32_to_cpu(val);
        if (size == 0)
                return;

        base = alloc_down(size, PAGE_SIZE, 0);
        if (base == 0)
                prom_panic("Could not allocate memory for RTAS\n");

        rtas_inst = call_prom("open", 1, 1, ADDR("/rtas"));
        if (!IHANDLE_VALID(rtas_inst)) {
                prom_printf("opening rtas package failed (%x)\n", rtas_inst);
                return;
        }

        prom_printf("instantiating rtas at 0x%x...", base);

        if (call_prom_ret("call-method", 3, 2, &entry,
                          ADDR("instantiate-rtas"),
                          rtas_inst, base) != 0
            || entry == 0) {
                prom_printf(" failed\n");
                return;
        }
        prom_printf(" done\n");

        reserve_mem(base, size);

        val = cpu_to_be32(base);
        prom_setprop(rtas_node, "/rtas", "linux,rtas-base",
                     &val, sizeof(val));
        val = cpu_to_be32(entry);
        prom_setprop(rtas_node, "/rtas", "linux,rtas-entry",
                     &val, sizeof(val));

        /* Check if it supports "query-cpu-stopped-state" */
        if (prom_getprop(rtas_node, "query-cpu-stopped-state",
                         &val, sizeof(val)) != PROM_ERROR)
                rtas_has_query_cpu_stopped = true;

        prom_debug("rtas base     = 0x%x\n", base);
        prom_debug("rtas entry    = 0x%x\n", entry);
        prom_debug("rtas size     = 0x%x\n", size);

        prom_debug("prom_instantiate_rtas: end...\n");
}

#ifdef CONFIG_PPC64
/*
 * Allocate room for and instantiate Stored Measurement Log (SML)
 */
static void __init prom_instantiate_sml(void)
{
        phandle ibmvtpm_node;
        ihandle ibmvtpm_inst;
        u32 entry = 0, size = 0, succ = 0;
        u64 base;
        __be32 val;

        prom_debug("prom_instantiate_sml: start...\n");

        ibmvtpm_node = call_prom("finddevice", 1, 1, ADDR("/vdevice/vtpm"));
        prom_debug("ibmvtpm_node: %x\n", ibmvtpm_node);
        if (!PHANDLE_VALID(ibmvtpm_node))
                return;

        ibmvtpm_inst = call_prom("open", 1, 1, ADDR("/vdevice/vtpm"));
        if (!IHANDLE_VALID(ibmvtpm_inst)) {
                prom_printf("opening vtpm package failed (%x)\n", ibmvtpm_inst);
                return;
        }

        if (prom_getprop(ibmvtpm_node, "ibm,sml-efi-reformat-supported",
                         &val, sizeof(val)) != PROM_ERROR) {
                if (call_prom_ret("call-method", 2, 2, &succ,
                                  ADDR("reformat-sml-to-efi-alignment"),
                                  ibmvtpm_inst) != 0 || succ == 0) {
                        prom_printf("Reformat SML to EFI alignment failed\n");
                        return;
                }

                if (call_prom_ret("call-method", 2, 2, &size,
                                  ADDR("sml-get-allocated-size"),
                                  ibmvtpm_inst) != 0 || size == 0) {
                        prom_printf("SML get allocated size failed\n");
                        return;
                }
        } else {
                if (call_prom_ret("call-method", 2, 2, &size,
                                  ADDR("sml-get-handover-size"),
                                  ibmvtpm_inst) != 0 || size == 0) {
                        prom_printf("SML get handover size failed\n");
                        return;
                }
        }

        base = alloc_down(size, PAGE_SIZE, 0);
        if (base == 0)
                prom_panic("Could not allocate memory for sml\n");

        prom_printf("instantiating sml at 0x%llx...", base);

        memset((void *)base, 0, size);

        if (call_prom_ret("call-method", 4, 2, &entry,
                          ADDR("sml-handover"),
                          ibmvtpm_inst, size, base) != 0 || entry == 0) {
                prom_printf("SML handover failed\n");
                return;
        }
        prom_printf(" done\n");

        reserve_mem(base, size);

        prom_setprop(ibmvtpm_node, "/vdevice/vtpm", "linux,sml-base",
                     &base, sizeof(base));
        prom_setprop(ibmvtpm_node, "/vdevice/vtpm", "linux,sml-size",
                     &size, sizeof(size));

        prom_debug("sml base     = 0x%llx\n", base);
        prom_debug("sml size     = 0x%x\n", size);

        prom_debug("prom_instantiate_sml: end...\n");
}

/*
 * Allocate room for and initialize TCE tables
 */
#ifdef __BIG_ENDIAN__
static void __init prom_initialize_tce_table(void)
{
        phandle node;
        ihandle phb_node;
        char compatible[64], type[64], model[64];
        char *path = prom_scratch;
        u64 base, align;
        u32 minalign, minsize;
        u64 tce_entry, *tce_entryp;
        u64 local_alloc_top, local_alloc_bottom;
        u64 i;

        if (prom_iommu_off)
                return;

        prom_debug("starting prom_initialize_tce_table\n");

        /* Cache current top of allocs so we reserve a single block */
        local_alloc_top = alloc_top_high;
        local_alloc_bottom = local_alloc_top;

        /* Search all nodes looking for PHBs. */
        for (node = 0; prom_next_node(&node); ) {

                compatible[0] = 0;
                type[0] = 0;
                model[0] = 0;
                prom_getprop(node, "compatible",
                             compatible, sizeof(compatible));
                prom_getprop(node, "device_type", type, sizeof(type));
                prom_getprop(node, "model", model, sizeof(model));

                if ((type[0] == 0) || (prom_strstr(type, "pci") == NULL))
                        continue;

                /* Keep the old logic intact to avoid regression. */
                if (compatible[0] != 0) {
                        if ((prom_strstr(compatible, "python") == NULL) &&
                            (prom_strstr(compatible, "Speedwagon") == NULL) &&
                            (prom_strstr(compatible, "Winnipeg") == NULL))
                                continue;
                } else if (model[0] != 0) {
                        if ((prom_strstr(model, "ython") == NULL) &&
                            (prom_strstr(model, "peedwagon") == NULL) &&
                            (prom_strstr(model, "innipeg") == NULL))
                                continue;
                }

                if (prom_getprop(node, "tce-table-minalign", &minalign,
                                 sizeof(minalign)) == PROM_ERROR)
                        minalign = 0;
                if (prom_getprop(node, "tce-table-minsize", &minsize,
                                 sizeof(minsize)) == PROM_ERROR)
                        minsize = 4UL << 20;

                /*
                 * Even though we read what OF wants, we just set the table
                 * size to 4 MB.  This is enough to map 2GB of PCI DMA space.
                 * By doing this, we avoid the pitfalls of trying to DMA to
                 * MMIO space and the DMA alias hole.
                 */
                minsize = 4UL << 20;

                /* Align to the greater of the align or size */
                align = max(minalign, minsize);
                base = alloc_down(minsize, align, 1);
                if (base == 0)
                        prom_panic("ERROR, cannot find space for TCE table.\n");
                if (base < local_alloc_bottom)
                        local_alloc_bottom = base;

                /* It seems OF doesn't null-terminate the path :-( */
                memset(path, 0, sizeof(prom_scratch));
                /* Call OF to setup the TCE hardware */
                if (call_prom("package-to-path", 3, 1, node,
                              path, sizeof(prom_scratch) - 1) == PROM_ERROR) {
                        prom_printf("package-to-path failed\n");
                }

                /* Save away the TCE table attributes for later use. */
                prom_setprop(node, path, "linux,tce-base", &base, sizeof(base));
                prom_setprop(node, path, "linux,tce-size", &minsize, sizeof(minsize));

                prom_debug("TCE table: %s\n", path);
                prom_debug("\tnode = 0x%x\n", node);
                prom_debug("\tbase = 0x%llx\n", base);
                prom_debug("\tsize = 0x%x\n", minsize);

                /* Initialize the table to have a one-to-one mapping
                 * over the allocated size.
                 */
                tce_entryp = (u64 *)base;
                for (i = 0; i < (minsize >> 3) ;tce_entryp++, i++) {
                        tce_entry = (i << PAGE_SHIFT);
                        tce_entry |= 0x3;
                        *tce_entryp = tce_entry;
                }

                prom_printf("opening PHB %s", path);
                phb_node = call_prom("open", 1, 1, path);
                if (phb_node == 0)
                        prom_printf("... failed\n");
                else
                        prom_printf("... done\n");

                call_prom("call-method", 6, 0, ADDR("set-64-bit-addressing"),
                          phb_node, -1, minsize,
                          (u32) base, (u32) (base >> 32));
                call_prom("close", 1, 0, phb_node);
        }

        reserve_mem(local_alloc_bottom, local_alloc_top - local_alloc_bottom);

        /* These are only really needed if there is a memory limit in
         * effect, but we don't know so export them always. */
        prom_tce_alloc_start = local_alloc_bottom;
        prom_tce_alloc_end = local_alloc_top;

        /* Flag the first invalid entry */
        prom_debug("ending prom_initialize_tce_table\n");
}
#endif /* __BIG_ENDIAN__ */
#endif /* CONFIG_PPC64 */

/*
 * With CHRP SMP we need to use the OF to start the other processors.
 * We can't wait until smp_boot_cpus (the OF is trashed by then)
 * so we have to put the processors into a holding pattern controlled
 * by the kernel (not OF) before we destroy the OF.
 *
 * This uses a chunk of low memory, puts some holding pattern
 * code there and sends the other processors off to there until
 * smp_boot_cpus tells them to do something.  The holding pattern
 * checks that address until its cpu # is there, when it is that
 * cpu jumps to __secondary_start().  smp_boot_cpus() takes care
 * of setting those values.
 *
 * We also use physical address 0x4 here to tell when a cpu
 * is in its holding pattern code.
 *
 * -- Cort
 */
/*
 * We want to reference the copy of __secondary_hold_* in the
 * 0 - 0x100 address range
 */
#define LOW_ADDR(x)     (((unsigned long) &(x)) & 0xff)

static void __init prom_hold_cpus(void)
{
        unsigned long i;
        phandle node;
        char type[64];
        unsigned long *spinloop
                = (void *) LOW_ADDR(__secondary_hold_spinloop);
        unsigned long *acknowledge
                = (void *) LOW_ADDR(__secondary_hold_acknowledge);
        unsigned long secondary_hold = LOW_ADDR(__secondary_hold);

        /*
         * On pseries, if RTAS supports "query-cpu-stopped-state",
         * we skip this stage, the CPUs will be started by the
         * kernel using RTAS.
         */
        if ((of_platform == PLATFORM_PSERIES ||
             of_platform == PLATFORM_PSERIES_LPAR) &&
            rtas_has_query_cpu_stopped) {
                prom_printf("prom_hold_cpus: skipped\n");
                return;
        }

        prom_debug("prom_hold_cpus: start...\n");
        prom_debug("    1) spinloop       = 0x%lx\n", (unsigned long)spinloop);
        prom_debug("    1) *spinloop      = 0x%lx\n", *spinloop);
        prom_debug("    1) acknowledge    = 0x%lx\n",
                   (unsigned long)acknowledge);
        prom_debug("    1) *acknowledge   = 0x%lx\n", *acknowledge);
        prom_debug("    1) secondary_hold = 0x%lx\n", secondary_hold);

        /* Set the common spinloop variable, so all of the secondary cpus
         * will block when they are awakened from their OF spinloop.
         * This must occur for both SMP and non SMP kernels, since OF will
         * be trashed when we move the kernel.
         */
        *spinloop = 0;

        /* look for cpus */
        for (node = 0; prom_next_node(&node); ) {
                unsigned int cpu_no;
                __be32 reg;

                type[0] = 0;
                prom_getprop(node, "device_type", type, sizeof(type));
                if (prom_strcmp(type, "cpu") != 0)
                        continue;

                /* Skip non-configured cpus. */
                if (prom_getprop(node, "status", type, sizeof(type)) > 0)
                        if (prom_strcmp(type, "okay") != 0)
                                continue;

                reg = cpu_to_be32(-1); /* make sparse happy */
                prom_getprop(node, "reg", &reg, sizeof(reg));
                cpu_no = be32_to_cpu(reg);

                prom_debug("cpu hw idx   = %u\n", cpu_no);

                /* Init the acknowledge var which will be reset by
                 * the secondary cpu when it awakens from its OF
                 * spinloop.
                 */
                *acknowledge = (unsigned long)-1;

                if (cpu_no != prom.cpu) {
                        /* Primary Thread of non-boot cpu or any thread */
                        prom_printf("starting cpu hw idx %u... ", cpu_no);
                        call_prom("start-cpu", 3, 0, node,
                                  secondary_hold, cpu_no);

                        for (i = 0; (i < 100000000) && 
                             (*acknowledge == ((unsigned long)-1)); i++ )
                                mb();

                        if (*acknowledge == cpu_no)
                                prom_printf("done\n");
                        else
                                prom_printf("failed: %lx\n", *acknowledge);
                }
#ifdef CONFIG_SMP
                else
                        prom_printf("boot cpu hw idx %u\n", cpu_no);
#endif /* CONFIG_SMP */
        }

        prom_debug("prom_hold_cpus: end...\n");
}


static void __init prom_init_client_services(unsigned long pp)
{
        /* Get a handle to the prom entry point before anything else */
        prom_entry = pp;

        /* get a handle for the stdout device */
        prom.chosen = call_prom("finddevice", 1, 1, ADDR("/chosen"));
        if (!PHANDLE_VALID(prom.chosen))
                prom_panic("cannot find chosen"); /* msg won't be printed :( */

        /* get device tree root */
        prom.root = call_prom("finddevice", 1, 1, ADDR("/"));
        if (!PHANDLE_VALID(prom.root))
                prom_panic("cannot find device tree root"); /* msg won't be printed :( */

        prom.mmumap = 0;
}

#ifdef CONFIG_PPC32
/*
 * For really old powermacs, we need to map things we claim.
 * For that, we need the ihandle of the mmu.
 * Also, on the longtrail, we need to work around other bugs.
 */
static void __init prom_find_mmu(void)
{
        phandle oprom;
        char version[64];

        oprom = call_prom("finddevice", 1, 1, ADDR("/openprom"));
        if (!PHANDLE_VALID(oprom))
                return;
        if (prom_getprop(oprom, "model", version, sizeof(version)) <= 0)
                return;
        version[sizeof(version) - 1] = 0;
        /* XXX might need to add other versions here */
        if (prom_strcmp(version, "Open Firmware, 1.0.5") == 0)
                of_workarounds = OF_WA_CLAIM;
        else if (prom_strncmp(version, "FirmWorks,3.", 12) == 0) {
                of_workarounds = OF_WA_CLAIM | OF_WA_LONGTRAIL;
                call_prom("interpret", 1, 1, "dev /memory 0 to allow-reclaim");
        } else
                return;
        prom.memory = call_prom("open", 1, 1, ADDR("/memory"));
        prom_getprop(prom.chosen, "mmu", &prom.mmumap,
                     sizeof(prom.mmumap));
        prom.mmumap = be32_to_cpu(prom.mmumap);
        if (!IHANDLE_VALID(prom.memory) || !IHANDLE_VALID(prom.mmumap))
                of_workarounds &= ~OF_WA_CLAIM;         /* hmmm */
}
#else
#define prom_find_mmu()
#endif

static void __init prom_init_stdout(void)
{
        char *path = of_stdout_device;
        char type[16];
        phandle stdout_node;
        __be32 val;

        if (prom_getprop(prom.chosen, "stdout", &val, sizeof(val)) <= 0)
                prom_panic("cannot find stdout");

        prom.stdout = be32_to_cpu(val);

        /* Get the full OF pathname of the stdout device */
        memset(path, 0, 256);
        call_prom("instance-to-path", 3, 1, prom.stdout, path, 255);
        prom_printf("OF stdout device is: %s\n", of_stdout_device);
        prom_setprop(prom.chosen, "/chosen", "linux,stdout-path",
                     path, prom_strlen(path) + 1);

        /* instance-to-package fails on PA-Semi */
        stdout_node = call_prom("instance-to-package", 1, 1, prom.stdout);
        if (stdout_node != PROM_ERROR) {
                val = cpu_to_be32(stdout_node);

                /* If it's a display, note it */
                memset(type, 0, sizeof(type));
                prom_getprop(stdout_node, "device_type", type, sizeof(type));
                if (prom_strcmp(type, "display") == 0)
                        prom_setprop(stdout_node, path, "linux,boot-display", NULL, 0);
        }
}

static int __init prom_find_machine_type(void)
{
        char compat[256];
        int len, i = 0;
#ifdef CONFIG_PPC64
        phandle rtas;
        int x;
#endif

        /* Look for a PowerMac or a Cell */
        len = prom_getprop(prom.root, "compatible",
                           compat, sizeof(compat)-1);
        if (len > 0) {
                compat[len] = 0;
                while (i < len) {
                        char *p = &compat[i];
                        int sl = prom_strlen(p);
                        if (sl == 0)
                                break;
                        if (prom_strstr(p, "Power Macintosh") ||
                            prom_strstr(p, "MacRISC"))
                                return PLATFORM_POWERMAC;
#ifdef CONFIG_PPC64
                        /* We must make sure we don't detect the IBM Cell
                         * blades as pSeries due to some firmware issues,
                         * so we do it here.
                         */
                        if (prom_strstr(p, "IBM,CBEA") ||
                            prom_strstr(p, "IBM,CPBW-1.0"))
                                return PLATFORM_GENERIC;
#endif /* CONFIG_PPC64 */
                        i += sl + 1;
                }
        }
#ifdef CONFIG_PPC64
        /* Try to figure out if it's an IBM pSeries or any other
         * PAPR compliant platform. We assume it is if :
         *  - /device_type is "chrp" (please, do NOT use that for future
         *    non-IBM designs !
         *  - it has /rtas
         */
        len = prom_getprop(prom.root, "device_type",
                           compat, sizeof(compat)-1);
        if (len <= 0)
                return PLATFORM_GENERIC;
        if (prom_strcmp(compat, "chrp"))
                return PLATFORM_GENERIC;

        /* Default to pSeries. We need to know if we are running LPAR */
        rtas = call_prom("finddevice", 1, 1, ADDR("/rtas"));
        if (!PHANDLE_VALID(rtas))
                return PLATFORM_GENERIC;
        x = prom_getproplen(rtas, "ibm,hypertas-functions");
        if (x != PROM_ERROR) {
                prom_debug("Hypertas detected, assuming LPAR !\n");
                return PLATFORM_PSERIES_LPAR;
        }
        return PLATFORM_PSERIES;
#else
        return PLATFORM_GENERIC;
#endif
}

static int __init prom_set_color(ihandle ih, int i, int r, int g, int b)
{
        return call_prom("call-method", 6, 1, ADDR("color!"), ih, i, b, g, r);
}

/*
 * If we have a display that we don't know how to drive,
 * we will want to try to execute OF's open method for it
 * later.  However, OF will probably fall over if we do that
 * we've taken over the MMU.
 * So we check whether we will need to open the display,
 * and if so, open it now.
 */
static void __init prom_check_displays(void)
{
        char type[16], *path;
        phandle node;
        ihandle ih;
        int i;

        static const unsigned char default_colors[] __initconst = {
                0x00, 0x00, 0x00,
                0x00, 0x00, 0xaa,
                0x00, 0xaa, 0x00,
                0x00, 0xaa, 0xaa,
                0xaa, 0x00, 0x00,
                0xaa, 0x00, 0xaa,
                0xaa, 0xaa, 0x00,
                0xaa, 0xaa, 0xaa,
                0x55, 0x55, 0x55,
                0x55, 0x55, 0xff,
                0x55, 0xff, 0x55,
                0x55, 0xff, 0xff,
                0xff, 0x55, 0x55,
                0xff, 0x55, 0xff,
                0xff, 0xff, 0x55,
                0xff, 0xff, 0xff
        };
        const unsigned char *clut;

        prom_debug("Looking for displays\n");
        for (node = 0; prom_next_node(&node); ) {
                memset(type, 0, sizeof(type));
                prom_getprop(node, "device_type", type, sizeof(type));
                if (prom_strcmp(type, "display") != 0)
                        continue;

                /* It seems OF doesn't null-terminate the path :-( */
                path = prom_scratch;
                memset(path, 0, sizeof(prom_scratch));

                /*
                 * leave some room at the end of the path for appending extra
                 * arguments
                 */
                if (call_prom("package-to-path", 3, 1, node, path,
                              sizeof(prom_scratch) - 10) == PROM_ERROR)
                        continue;
                prom_printf("found display   : %s, opening... ", path);
                
                ih = call_prom("open", 1, 1, path);
                if (ih == 0) {
                        prom_printf("failed\n");
                        continue;
                }

                /* Success */
                prom_printf("done\n");
                prom_setprop(node, path, "linux,opened", NULL, 0);

                /* Setup a usable color table when the appropriate
                 * method is available. Should update this to set-colors */
                clut = default_colors;
                for (i = 0; i < 16; i++, clut += 3)
                        if (prom_set_color(ih, i, clut[0], clut[1],
                                           clut[2]) != 0)
                                break;

#ifdef CONFIG_LOGO_LINUX_CLUT224
                clut = PTRRELOC(logo_linux_clut224.clut);
                for (i = 0; i < logo_linux_clut224.clutsize; i++, clut += 3)
                        if (prom_set_color(ih, i + 32, clut[0], clut[1],
                                           clut[2]) != 0)
                                break;
#endif /* CONFIG_LOGO_LINUX_CLUT224 */

#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
                if (prom_getprop(node, "linux,boot-display", NULL, 0) !=
                    PROM_ERROR) {
                        u32 width, height, pitch, addr;

                        prom_printf("Setting btext !\n");

                        if (prom_getprop(node, "width", &width, 4) == PROM_ERROR)
                                return;

                        if (prom_getprop(node, "height", &height, 4) == PROM_ERROR)
                                return;

                        if (prom_getprop(node, "linebytes", &pitch, 4) == PROM_ERROR)
                                return;

                        if (prom_getprop(node, "address", &addr, 4) == PROM_ERROR)
                                return;

                        prom_printf("W=%d H=%d LB=%d addr=0x%x\n",
                                    width, height, pitch, addr);
                        btext_setup_display(width, height, 8, pitch, addr);
                        btext_prepare_BAT();
                }
#endif /* CONFIG_PPC_EARLY_DEBUG_BOOTX */
        }
}


/* Return (relocated) pointer to this much memory: moves initrd if reqd. */
static void __init *make_room(unsigned long *mem_start, unsigned long *mem_end,
                              unsigned long needed, unsigned long align)
{
        void *ret;

        *mem_start = ALIGN(*mem_start, align);
        while ((*mem_start + needed) > *mem_end) {
                unsigned long room, chunk;

                prom_debug("Chunk exhausted, claiming more at %lx...\n",
                           alloc_bottom);
                room = alloc_top - alloc_bottom;
                if (room > DEVTREE_CHUNK_SIZE)
                        room = DEVTREE_CHUNK_SIZE;
                if (room < PAGE_SIZE)
                        prom_panic("No memory for flatten_device_tree "
                                   "(no room)\n");
                chunk = alloc_up(room, 0);
                if (chunk == 0)
                        prom_panic("No memory for flatten_device_tree "
                                   "(claim failed)\n");
                *mem_end = chunk + room;
        }

        ret = (void *)*mem_start;
        *mem_start += needed;

        return ret;
}

#define dt_push_token(token, mem_start, mem_end) do {                   \
                void *room = make_room(mem_start, mem_end, 4, 4);       \
                *(__be32 *)room = cpu_to_be32(token);                   \
        } while(0)

static unsigned long __init dt_find_string(char *str)
{
        char *s, *os;

        s = os = (char *)dt_string_start;
        s += 4;
        while (s <  (char *)dt_string_end) {
                if (prom_strcmp(s, str) == 0)
                        return s - os;
                s += prom_strlen(s) + 1;
        }
        return 0;
}

/*
 * The Open Firmware 1275 specification states properties must be 31 bytes or
 * less, however not all firmwares obey this. Make it 64 bytes to be safe.
 */
#define MAX_PROPERTY_NAME 64

static void __init scan_dt_build_strings(phandle node,
                                         unsigned long *mem_start,
                                         unsigned long *mem_end)
{
        char *prev_name, *namep, *sstart;
        unsigned long soff;
        phandle child;

        sstart =  (char *)dt_string_start;

        /* get and store all property names */
        prev_name = "";
        for (;;) {
                /* 64 is max len of name including nul. */
                namep = make_room(mem_start, mem_end, MAX_PROPERTY_NAME, 1);
                if (call_prom("nextprop", 3, 1, node, prev_name, namep) != 1) {
                        /* No more nodes: unwind alloc */
                        *mem_start = (unsigned long)namep;
                        break;
                }

                /* skip "name" */
                if (prom_strcmp(namep, "name") == 0) {
                        *mem_start = (unsigned long)namep;
                        prev_name = "name";
                        continue;
                }
                /* get/create string entry */
                soff = dt_find_string(namep);
                if (soff != 0) {
                        *mem_start = (unsigned long)namep;
                        namep = sstart + soff;
                } else {
                        /* Trim off some if we can */
                        *mem_start = (unsigned long)namep + prom_strlen(namep) + 1;
                        dt_string_end = *mem_start;
                }
                prev_name = namep;
        }

        /* do all our children */
        child = call_prom("child", 1, 1, node);
        while (child != 0) {
                scan_dt_build_strings(child, mem_start, mem_end);
                child = call_prom("peer", 1, 1, child);
        }
}

static void __init scan_dt_build_struct(phandle node, unsigned long *mem_start,
                                        unsigned long *mem_end)
{
        phandle child;
        char *namep, *prev_name, *sstart, *p, *ep, *lp, *path;
        unsigned long soff;
        unsigned char *valp;
        static char pname[MAX_PROPERTY_NAME] __prombss;
        int l, room, has_phandle = 0;

        dt_push_token(OF_DT_BEGIN_NODE, mem_start, mem_end);

        /* get the node's full name */
        namep = (char *)*mem_start;
        room = *mem_end - *mem_start;
        if (room > 255)
                room = 255;
        l = call_prom("package-to-path", 3, 1, node, namep, room);
        if (l >= 0) {
                /* Didn't fit?  Get more room. */
                if (l >= room) {
                        if (l >= *mem_end - *mem_start)
                                namep = make_room(mem_start, mem_end, l+1, 1);
                        call_prom("package-to-path", 3, 1, node, namep, l);
                }
                namep[l] = '\0';

                /* Fixup an Apple bug where they have bogus \0 chars in the
                 * middle of the path in some properties, and extract
                 * the unit name (everything after the last '/').
                 */
                for (lp = p = namep, ep = namep + l; p < ep; p++) {
                        if (*p == '/')
                                lp = namep;
                        else if (*p != 0)
                                *lp++ = *p;
                }
                *lp = 0;
                *mem_start = ALIGN((unsigned long)lp + 1, 4);
        }

        /* get it again for debugging */
        path = prom_scratch;
        memset(path, 0, sizeof(prom_scratch));
        call_prom("package-to-path", 3, 1, node, path, sizeof(prom_scratch) - 1);

        /* get and store all properties */
        prev_name = "";
        sstart = (char *)dt_string_start;
        for (;;) {
                if (call_prom("nextprop", 3, 1, node, prev_name,
                              pname) != 1)
                        break;

                /* skip "name" */
                if (prom_strcmp(pname, "name") == 0) {
                        prev_name = "name";
                        continue;
                }

                /* find string offset */
                soff = dt_find_string(pname);
                if (soff == 0) {
                        prom_printf("WARNING: Can't find string index for"
                                    " <%s>, node %s\n", pname, path);
                        break;
                }
                prev_name = sstart + soff;

                /* get length */
                l = call_prom("getproplen", 2, 1, node, pname);

                /* sanity checks */
                if (l == PROM_ERROR)
                        continue;

                /* push property head */
                dt_push_token(OF_DT_PROP, mem_start, mem_end);
                dt_push_token(l, mem_start, mem_end);
                dt_push_token(soff, mem_start, mem_end);

                /* push property content */
                valp = make_room(mem_start, mem_end, l, 4);
                call_prom("getprop", 4, 1, node, pname, valp, l);
                *mem_start = ALIGN(*mem_start, 4);

                if (!prom_strcmp(pname, "phandle"))
                        has_phandle = 1;
        }

        /* Add a "phandle" property if none already exist */
        if (!has_phandle) {
                soff = dt_find_string("phandle");
                if (soff == 0)
                        prom_printf("WARNING: Can't find string index for <phandle> node %s\n", path);
                else {
                        dt_push_token(OF_DT_PROP, mem_start, mem_end);
                        dt_push_token(4, mem_start, mem_end);
                        dt_push_token(soff, mem_start, mem_end);
                        valp = make_room(mem_start, mem_end, 4, 4);
                        *(__be32 *)valp = cpu_to_be32(node);
                }
        }

        /* do all our children */
        child = call_prom("child", 1, 1, node);
        while (child != 0) {
                scan_dt_build_struct(child, mem_start, mem_end);
                child = call_prom("peer", 1, 1, child);
        }

        dt_push_token(OF_DT_END_NODE, mem_start, mem_end);
}

static void __init flatten_device_tree(void)
{
        phandle root;
        unsigned long mem_start, mem_end, room;
        struct boot_param_header *hdr;
        char *namep;
        u64 *rsvmap;

        /*
         * Check how much room we have between alloc top & bottom (+/- a
         * few pages), crop to 1MB, as this is our "chunk" size
         */
        room = alloc_top - alloc_bottom - 0x4000;
        if (room > DEVTREE_CHUNK_SIZE)
                room = DEVTREE_CHUNK_SIZE;
        prom_debug("starting device tree allocs at %lx\n", alloc_bottom);

        /* Now try to claim that */
        mem_start = (unsigned long)alloc_up(room, PAGE_SIZE);
        if (mem_start == 0)
                prom_panic("Can't allocate initial device-tree chunk\n");
        mem_end = mem_start + room;

        /* Get root of tree */
        root = call_prom("peer", 1, 1, (phandle)0);
        if (root == (phandle)0)
                prom_panic ("couldn't get device tree root\n");

        /* Build header and make room for mem rsv map */ 
        mem_start = ALIGN(mem_start, 4);
        hdr = make_room(&mem_start, &mem_end,
                        sizeof(struct boot_param_header), 4);
        dt_header_start = (unsigned long)hdr;
        rsvmap = make_room(&mem_start, &mem_end, sizeof(mem_reserve_map), 8);

        /* Start of strings */
        mem_start = PAGE_ALIGN(mem_start);
        dt_string_start = mem_start;
        mem_start += 4; /* hole */

        /* Add "phandle" in there, we'll need it */
        namep = make_room(&mem_start, &mem_end, 16, 1);
        prom_strscpy_pad(namep, "phandle", sizeof("phandle"));
        mem_start = (unsigned long)namep + prom_strlen(namep) + 1;

        /* Build string array */
        prom_printf("Building dt strings...\n"); 
        scan_dt_build_strings(root, &mem_start, &mem_end);
        dt_string_end = mem_start;

        /* Build structure */
        mem_start = PAGE_ALIGN(mem_start);
        dt_struct_start = mem_start;
        prom_printf("Building dt structure...\n"); 
        scan_dt_build_struct(root, &mem_start, &mem_end);
        dt_push_token(OF_DT_END, &mem_start, &mem_end);
        dt_struct_end = PAGE_ALIGN(mem_start);

        /* Finish header */
        hdr->boot_cpuid_phys = cpu_to_be32(prom.cpu);
        hdr->magic = cpu_to_be32(OF_DT_HEADER);
        hdr->totalsize = cpu_to_be32(dt_struct_end - dt_header_start);
        hdr->off_dt_struct = cpu_to_be32(dt_struct_start - dt_header_start);
        hdr->off_dt_strings = cpu_to_be32(dt_string_start - dt_header_start);
        hdr->dt_strings_size = cpu_to_be32(dt_string_end - dt_string_start);
        hdr->off_mem_rsvmap = cpu_to_be32(((unsigned long)rsvmap) - dt_header_start);
        hdr->version = cpu_to_be32(OF_DT_VERSION);
        /* Version 16 is not backward compatible */
        hdr->last_comp_version = cpu_to_be32(0x10);

        /* Copy the reserve map in */
        memcpy(rsvmap, mem_reserve_map, sizeof(mem_reserve_map));

#ifdef DEBUG_PROM
        {
                int i;
                prom_printf("reserved memory map:\n");
                for (i = 0; i < mem_reserve_cnt; i++)
                        prom_printf("  %llx - %llx\n",
                                    be64_to_cpu(mem_reserve_map[i].base),
                                    be64_to_cpu(mem_reserve_map[i].size));
        }
#endif
        /* Bump mem_reserve_cnt to cause further reservations to fail
         * since it's too late.
         */
        mem_reserve_cnt = MEM_RESERVE_MAP_SIZE;

        prom_printf("Device tree strings 0x%lx -> 0x%lx\n",
                    dt_string_start, dt_string_end);
        prom_printf("Device tree struct  0x%lx -> 0x%lx\n",
                    dt_struct_start, dt_struct_end);
}

#ifdef CONFIG_PPC_MAPLE
/* PIBS Version 1.05.0000 04/26/2005 has an incorrect /ht/isa/ranges property.
 * The values are bad, and it doesn't even have the right number of cells. */
static void __init fixup_device_tree_maple(void)
{
        phandle isa;
        u32 rloc = 0x01002000; /* IO space; PCI device = 4 */
        u32 isa_ranges[6];
        char *name;

        name = "/ht@0/isa@4";
        isa = call_prom("finddevice", 1, 1, ADDR(name));
        if (!PHANDLE_VALID(isa)) {
                name = "/ht@0/isa@6";
                isa = call_prom("finddevice", 1, 1, ADDR(name));
                rloc = 0x01003000; /* IO space; PCI device = 6 */
        }
        if (!PHANDLE_VALID(isa))
                return;

        if (prom_getproplen(isa, "ranges") != 12)
                return;
        if (prom_getprop(isa, "ranges", isa_ranges, sizeof(isa_ranges))
                == PROM_ERROR)
                return;

        if (isa_ranges[0] != 0x1 ||
                isa_ranges[1] != 0xf4000000 ||
                isa_ranges[2] != 0x00010000)
                return;

        prom_printf("Fixing up bogus ISA range on Maple/Apache...\n");

        isa_ranges[0] = 0x1;
        isa_ranges[1] = 0x0;
        isa_ranges[2] = rloc;
        isa_ranges[3] = 0x0;
        isa_ranges[4] = 0x0;
        isa_ranges[5] = 0x00010000;
        prom_setprop(isa, name, "ranges",
                        isa_ranges, sizeof(isa_ranges));
}

#define CPC925_MC_START         0xf8000000
#define CPC925_MC_LENGTH        0x1000000
/* The values for memory-controller don't have right number of cells */
static void __init fixup_device_tree_maple_memory_controller(void)
{
        phandle mc;
        u32 mc_reg[4];
        char *name = "/hostbridge@f8000000";
        u32 ac, sc;

        mc = call_prom("finddevice", 1, 1, ADDR(name));
        if (!PHANDLE_VALID(mc))
                return;

        if (prom_getproplen(mc, "reg") != 8)
                return;

        prom_getprop(prom.root, "#address-cells", &ac, sizeof(ac));
        prom_getprop(prom.root, "#size-cells", &sc, sizeof(sc));
        if ((ac != 2) || (sc != 2))
                return;

        if (prom_getprop(mc, "reg", mc_reg, sizeof(mc_reg)) == PROM_ERROR)
                return;

        if (mc_reg[0] != CPC925_MC_START || mc_reg[1] != CPC925_MC_LENGTH)
                return;

        prom_printf("Fixing up bogus hostbridge on Maple...\n");

        mc_reg[0] = 0x0;
        mc_reg[1] = CPC925_MC_START;
        mc_reg[2] = 0x0;
        mc_reg[3] = CPC925_MC_LENGTH;
        prom_setprop(mc, name, "reg", mc_reg, sizeof(mc_reg));
}
#else
#define fixup_device_tree_maple()
#define fixup_device_tree_maple_memory_controller()
#endif

#ifdef CONFIG_PPC_CHRP
/*
 * Pegasos and BriQ lacks the "ranges" property in the isa node
 * Pegasos needs decimal IRQ 14/15, not hexadecimal
 * Pegasos has the IDE configured in legacy mode, but advertised as native
 */
static void __init fixup_device_tree_chrp(void)
{
        phandle ph;
        u32 prop[6];
        u32 rloc = 0x01006000; /* IO space; PCI device = 12 */
        char *name;
        int rc;

        name = "/pci@80000000/isa@c";
        ph = call_prom("finddevice", 1, 1, ADDR(name));
        if (!PHANDLE_VALID(ph)) {
                name = "/pci@ff500000/isa@6";
                ph = call_prom("finddevice", 1, 1, ADDR(name));
                rloc = 0x01003000; /* IO space; PCI device = 6 */
        }
        if (PHANDLE_VALID(ph)) {
                rc = prom_getproplen(ph, "ranges");
                if (rc == 0 || rc == PROM_ERROR) {
                        prom_printf("Fixing up missing ISA range on Pegasos...\n");

                        prop[0] = 0x1;
                        prop[1] = 0x0;
                        prop[2] = rloc;
                        prop[3] = 0x0;
                        prop[4] = 0x0;
                        prop[5] = 0x00010000;
                        prom_setprop(ph, name, "ranges", prop, sizeof(prop));
                }
        }

        name = "/pci@80000000/ide@C,1";
        ph = call_prom("finddevice", 1, 1, ADDR(name));
        if (PHANDLE_VALID(ph)) {
                prom_printf("Fixing up IDE interrupt on Pegasos...\n");
                prop[0] = 14;
                prop[1] = 0x0;
                prom_setprop(ph, name, "interrupts", prop, 2*sizeof(u32));
                prom_printf("Fixing up IDE class-code on Pegasos...\n");
                rc = prom_getprop(ph, "class-code", prop, sizeof(u32));
                if (rc == sizeof(u32)) {
                        prop[0] &= ~0x5;
                        prom_setprop(ph, name, "class-code", prop, sizeof(u32));
                }
        }
}
#else
#define fixup_device_tree_chrp()
#endif

#if defined(CONFIG_PPC64) && defined(CONFIG_PPC_PMAC)
static void __init fixup_device_tree_pmac(void)
{
        phandle u3, i2c, mpic;
        u32 u3_rev;
        u32 interrupts[2];
        u32 parent;

        /* Some G5s have a missing interrupt definition, fix it up here */
        u3 = call_prom("finddevice", 1, 1, ADDR("/u3@0,f8000000"));
        if (!PHANDLE_VALID(u3))
                return;
        i2c = call_prom("finddevice", 1, 1, ADDR("/u3@0,f8000000/i2c@f8001000"));
        if (!PHANDLE_VALID(i2c))
                return;
        mpic = call_prom("finddevice", 1, 1, ADDR("/u3@0,f8000000/mpic@f8040000"));
        if (!PHANDLE_VALID(mpic))
                return;

        /* check if proper rev of u3 */
        if (prom_getprop(u3, "device-rev", &u3_rev, sizeof(u3_rev))
            == PROM_ERROR)
                return;
        if (u3_rev < 0x35 || u3_rev > 0x39)
                return;
        /* does it need fixup ? */
        if (prom_getproplen(i2c, "interrupts") > 0)
                return;

        prom_printf("fixing up bogus interrupts for u3 i2c...\n");

        /* interrupt on this revision of u3 is number 0 and level */
        interrupts[0] = 0;
        interrupts[1] = 1;
        prom_setprop(i2c, "/u3@0,f8000000/i2c@f8001000", "interrupts",
                     &interrupts, sizeof(interrupts));
        parent = (u32)mpic;
        prom_setprop(i2c, "/u3@0,f8000000/i2c@f8001000", "interrupt-parent",
                     &parent, sizeof(parent));
}
#else
#define fixup_device_tree_pmac()
#endif

#ifdef CONFIG_PPC_EFIKA
/*
 * The MPC5200 FEC driver requires an phy-handle property to tell it how
 * to talk to the phy.  If the phy-handle property is missing, then this
 * function is called to add the appropriate nodes and link it to the
 * ethernet node.
 */
static void __init fixup_device_tree_efika_add_phy(void)
{
        u32 node;
        char prop[64];
        int rv;

        /* Check if /builtin/ethernet exists - bail if it doesn't */
        node = call_prom("finddevice", 1, 1, ADDR("/builtin/ethernet"));
        if (!PHANDLE_VALID(node))
                return;

        /* Check if the phy-handle property exists - bail if it does */
        rv = prom_getprop(node, "phy-handle", prop, sizeof(prop));
        if (!rv)
                return;

        /*
         * At this point the ethernet device doesn't have a phy described.
         * Now we need to add the missing phy node and linkage
         */

        /* Check for an MDIO bus node - if missing then create one */
        node = call_prom("finddevice", 1, 1, ADDR("/builtin/mdio"));
        if (!PHANDLE_VALID(node)) {
                prom_printf("Adding Ethernet MDIO node\n");
                call_prom("interpret", 1, 1,
                        " s\" /builtin\" find-device"
                        " new-device"
                                " 1 encode-int s\" #address-cells\" property"
                                " 0 encode-int s\" #size-cells\" property"
                                " s\" mdio\" device-name"
                                " s\" fsl,mpc5200b-mdio\" encode-string"
                                " s\" compatible\" property"
                                " 0xf0003000 0x400 reg"
                                " 0x2 encode-int"
                                " 0x5 encode-int encode+"
                                " 0x3 encode-int encode+"
                                " s\" interrupts\" property"
                        " finish-device");
        }

        /* Check for a PHY device node - if missing then create one and
         * give it's phandle to the ethernet node */
        node = call_prom("finddevice", 1, 1,
                         ADDR("/builtin/mdio/ethernet-phy"));
        if (!PHANDLE_VALID(node)) {
                prom_printf("Adding Ethernet PHY node\n");
                call_prom("interpret", 1, 1,
                        " s\" /builtin/mdio\" find-device"
                        " new-device"
                                " s\" ethernet-phy\" device-name"
                                " 0x10 encode-int s\" reg\" property"
                                " my-self"
                                " ihandle>phandle"
                        " finish-device"
                        " s\" /builtin/ethernet\" find-device"
                                " encode-int"
                                " s\" phy-handle\" property"
                        " device-end");
        }
}

static void __init fixup_device_tree_efika(void)
{
        int sound_irq[3] = { 2, 2, 0 };
        int bcomm_irq[3*16] = { 3,0,0, 3,1,0, 3,2,0, 3,3,0,
                                3,4,0, 3,5,0, 3,6,0, 3,7,0,
                                3,8,0, 3,9,0, 3,10,0, 3,11,0,
                                3,12,0, 3,13,0, 3,14,0, 3,15,0 };
        u32 node;
        char prop[64];
        int rv, len;

        /* Check if we're really running on a EFIKA */
        node = call_prom("finddevice", 1, 1, ADDR("/"));
        if (!PHANDLE_VALID(node))
                return;

        rv = prom_getprop(node, "model", prop, sizeof(prop));
        if (rv == PROM_ERROR)
                return;
        if (prom_strcmp(prop, "EFIKA5K2"))
                return;

        prom_printf("Applying EFIKA device tree fixups\n");

        /* Claiming to be 'chrp' is death */
        node = call_prom("finddevice", 1, 1, ADDR("/"));
        rv = prom_getprop(node, "device_type", prop, sizeof(prop));
        if (rv != PROM_ERROR && (prom_strcmp(prop, "chrp") == 0))
                prom_setprop(node, "/", "device_type", "efika", sizeof("efika"));

        /* CODEGEN,description is exposed in /proc/cpuinfo so
           fix that too */
        rv = prom_getprop(node, "CODEGEN,description", prop, sizeof(prop));
        if (rv != PROM_ERROR && (prom_strstr(prop, "CHRP")))
                prom_setprop(node, "/", "CODEGEN,description",
                             "Efika 5200B PowerPC System",
                             sizeof("Efika 5200B PowerPC System"));

        /* Fixup bestcomm interrupts property */
        node = call_prom("finddevice", 1, 1, ADDR("/builtin/bestcomm"));
        if (PHANDLE_VALID(node)) {
                len = prom_getproplen(node, "interrupts");
                if (len == 12) {
                        prom_printf("Fixing bestcomm interrupts property\n");
                        prom_setprop(node, "/builtin/bestcom", "interrupts",
                                     bcomm_irq, sizeof(bcomm_irq));
                }
        }

        /* Fixup sound interrupts property */
        node = call_prom("finddevice", 1, 1, ADDR("/builtin/sound"));
        if (PHANDLE_VALID(node)) {
                rv = prom_getprop(node, "interrupts", prop, sizeof(prop));
                if (rv == PROM_ERROR) {
                        prom_printf("Adding sound interrupts property\n");
                        prom_setprop(node, "/builtin/sound", "interrupts",
                                     sound_irq, sizeof(sound_irq));
                }
        }

        /* Make sure ethernet phy-handle property exists */
        fixup_device_tree_efika_add_phy();
}
#else
#define fixup_device_tree_efika()
#endif

#ifdef CONFIG_PPC_PASEMI_NEMO
/*
 * CFE supplied on Nemo is broken in several ways, biggest
 * problem is that it reassigns ISA interrupts to unused mpic ints.
 * Add an interrupt-controller property for the io-bridge to use
 * and correct the ints so we can attach them to an irq_domain
 */
static void __init fixup_device_tree_pasemi(void)
{
        u32 interrupts[2], parent, rval, val = 0;
        char *name, *pci_name;
        phandle iob, node;

        /* Find the root pci node */
        name = "/pxp@0,e0000000";
        iob = call_prom("finddevice", 1, 1, ADDR(name));
        if (!PHANDLE_VALID(iob))
                return;

        /* check if interrupt-controller node set yet */
        if (prom_getproplen(iob, "interrupt-controller") !=PROM_ERROR)
                return;

        prom_printf("adding interrupt-controller property for SB600...\n");

        prom_setprop(iob, name, "interrupt-controller", &val, 0);

        pci_name = "/pxp@0,e0000000/pci@11";
        node = call_prom("finddevice", 1, 1, ADDR(pci_name));
        parent = ADDR(iob);

        for( ; prom_next_node(&node); ) {
                /* scan each node for one with an interrupt */
                if (!PHANDLE_VALID(node))
                        continue;

                rval = prom_getproplen(node, "interrupts");
                if (rval == 0 || rval == PROM_ERROR)
                        continue;

                prom_getprop(node, "interrupts", &interrupts, sizeof(interrupts));
                if ((interrupts[0] < 212) || (interrupts[0] > 222))
                        continue;

                /* found a node, update both interrupts and interrupt-parent */
                if ((interrupts[0] >= 212) && (interrupts[0] <= 215))
                        interrupts[0] -= 203;
                if ((interrupts[0] >= 216) && (interrupts[0] <= 220))
                        interrupts[0] -= 213;
                if (interrupts[0] == 221)
                        interrupts[0] = 14;
                if (interrupts[0] == 222)
                        interrupts[0] = 8;

                prom_setprop(node, pci_name, "interrupts", interrupts,
                                        sizeof(interrupts));
                prom_setprop(node, pci_name, "interrupt-parent", &parent,
                                        sizeof(parent));
        }

        /*
         * The io-bridge has device_type set to 'io-bridge' change it to 'isa'
         * so that generic isa-bridge code can add the SB600 and its on-board
         * peripherals.
         */
        name = "/pxp@0,e0000000/io-bridge@0";
        iob = call_prom("finddevice", 1, 1, ADDR(name));
        if (!PHANDLE_VALID(iob))
                return;

        /* device_type is already set, just change it. */

        prom_printf("Changing device_type of SB600 node...\n");

        prom_setprop(iob, name, "device_type", "isa", sizeof("isa"));
}
#else   /* !CONFIG_PPC_PASEMI_NEMO */
static inline void fixup_device_tree_pasemi(void) { }
#endif

static void __init fixup_device_tree(void)
{
        fixup_device_tree_maple();
        fixup_device_tree_maple_memory_controller();
        fixup_device_tree_chrp();
        fixup_device_tree_pmac();
        fixup_device_tree_efika();
        fixup_device_tree_pasemi();
}

static void __init prom_find_boot_cpu(void)
{
        __be32 rval;
        ihandle prom_cpu;
        phandle cpu_pkg;

        rval = 0;
        if (prom_getprop(prom.chosen, "cpu", &rval, sizeof(rval)) <= 0)
                return;
        prom_cpu = be32_to_cpu(rval);

        cpu_pkg = call_prom("instance-to-package", 1, 1, prom_cpu);

        if (!PHANDLE_VALID(cpu_pkg))
                return;

        prom_getprop(cpu_pkg, "reg", &rval, sizeof(rval));
        prom.cpu = be32_to_cpu(rval);

        prom_debug("Booting CPU hw index = %d\n", prom.cpu);
}

static void __init prom_check_initrd(unsigned long r3, unsigned long r4)
{
#ifdef CONFIG_BLK_DEV_INITRD
        if (r3 && r4 && r4 != 0xdeadbeef) {
                __be64 val;

                prom_initrd_start = is_kernel_addr(r3) ? __pa(r3) : r3;
                prom_initrd_end = prom_initrd_start + r4;

                val = cpu_to_be64(prom_initrd_start);
                prom_setprop(prom.chosen, "/chosen", "linux,initrd-start",
                             &val, sizeof(val));
                val = cpu_to_be64(prom_initrd_end);
                prom_setprop(prom.chosen, "/chosen", "linux,initrd-end",
                             &val, sizeof(val));

                reserve_mem(prom_initrd_start,
                            prom_initrd_end - prom_initrd_start);

                prom_debug("initrd_start=0x%lx\n", prom_initrd_start);
                prom_debug("initrd_end=0x%lx\n", prom_initrd_end);
        }
#endif /* CONFIG_BLK_DEV_INITRD */
}

#ifdef CONFIG_PPC_SVM
/*
 * Perform the Enter Secure Mode ultracall.
 */
static int enter_secure_mode(unsigned long kbase, unsigned long fdt)
{
        register unsigned long r3 asm("r3") = UV_ESM;
        register unsigned long r4 asm("r4") = kbase;
        register unsigned long r5 asm("r5") = fdt;

        asm volatile("sc 2" : "+r"(r3) : "r"(r4), "r"(r5));

        return r3;
}

/*
 * Call the Ultravisor to transfer us to secure memory if we have an ESM blob.
 */
static void __init setup_secure_guest(unsigned long kbase, unsigned long fdt)
{
        int ret;

        if (!prom_svm_enable)
                return;

        /* Switch to secure mode. */
        prom_printf("Switching to secure mode.\n");

        /*
         * The ultravisor will do an integrity check of the kernel image but we
         * relocated it so the check will fail. Restore the original image by
         * relocating it back to the kernel virtual base address.
         */
        relocate(KERNELBASE);

        ret = enter_secure_mode(kbase, fdt);

        /* Relocate the kernel again. */
        relocate(kbase);

        if (ret != U_SUCCESS) {
                prom_printf("Returned %d from switching to secure mode.\n", ret);
                prom_rtas_os_term("Switch to secure mode failed.\n");
        }
}
#else
static void __init setup_secure_guest(unsigned long kbase, unsigned long fdt)
{
}
#endif /* CONFIG_PPC_SVM */

/*
 * We enter here early on, when the Open Firmware prom is still
 * handling exceptions and the MMU hash table for us.
 */

unsigned long __init prom_init(unsigned long r3, unsigned long r4,
                               unsigned long pp,
                               unsigned long r6, unsigned long r7,
                               unsigned long kbase)
{       
        unsigned long hdr;

#ifdef CONFIG_PPC32
        unsigned long offset = reloc_offset();
        reloc_got2(offset);
#endif

        /*
         * First zero the BSS
         */
        memset(&__bss_start, 0, __bss_stop - __bss_start);

        /*
         * Init interface to Open Firmware, get some node references,
         * like /chosen
         */
        prom_init_client_services(pp);

        /*
         * See if this OF is old enough that we need to do explicit maps
         * and other workarounds
         */
        prom_find_mmu();

        /*
         * Init prom stdout device
         */
        prom_init_stdout();

        prom_printf("Preparing to boot %s", linux_banner);

        /*
         * Get default machine type. At this point, we do not differentiate
         * between pSeries SMP and pSeries LPAR
         */
        of_platform = prom_find_machine_type();
        prom_printf("Detected machine type: %x\n", of_platform);

#ifndef CONFIG_NONSTATIC_KERNEL
        /* Bail if this is a kdump kernel. */
        if (PHYSICAL_START > 0)
                prom_panic("Error: You can't boot a kdump kernel from OF!\n");
#endif

        /*
         * Check for an initrd
         */
        prom_check_initrd(r3, r4);

        /*
         * Do early parsing of command line
         */
        early_cmdline_parse();

#ifdef CONFIG_PPC_PSERIES
        /*
         * On pSeries, inform the firmware about our capabilities
         */
        if (of_platform == PLATFORM_PSERIES ||
            of_platform == PLATFORM_PSERIES_LPAR)
                prom_send_capabilities();
#endif

        /*
         * Copy the CPU hold code
         */
        if (of_platform != PLATFORM_POWERMAC)
                copy_and_flush(0, kbase, 0x100, 0);

        /*
         * Initialize memory management within prom_init
         */
        prom_init_mem();

        /*
         * Determine which cpu is actually running right _now_
         */
        prom_find_boot_cpu();

        /* 
         * Initialize display devices
         */
        prom_check_displays();

#if defined(CONFIG_PPC64) && defined(__BIG_ENDIAN__)
        /*
         * Initialize IOMMU (TCE tables) on pSeries. Do that before anything else
         * that uses the allocator, we need to make sure we get the top of memory
         * available for us here...
         */
        if (of_platform == PLATFORM_PSERIES)
                prom_initialize_tce_table();
#endif

        /*
         * On non-powermacs, try to instantiate RTAS. PowerMacs don't
         * have a usable RTAS implementation.
         */
        if (of_platform != PLATFORM_POWERMAC)
                prom_instantiate_rtas();

#ifdef CONFIG_PPC64
        /* instantiate sml */
        prom_instantiate_sml();
#endif

        /*
         * On non-powermacs, put all CPUs in spin-loops.
         *
         * PowerMacs use a different mechanism to spin CPUs
         *
         * (This must be done after instanciating RTAS)
         */
        if (of_platform != PLATFORM_POWERMAC)
                prom_hold_cpus();

        /*
         * Fill in some infos for use by the kernel later on
         */
        if (prom_memory_limit) {
                __be64 val = cpu_to_be64(prom_memory_limit);
                prom_setprop(prom.chosen, "/chosen", "linux,memory-limit",
                             &val, sizeof(val));
        }
#ifdef CONFIG_PPC64
        if (prom_iommu_off)
                prom_setprop(prom.chosen, "/chosen", "linux,iommu-off",
                             NULL, 0);

        if (prom_iommu_force_on)
                prom_setprop(prom.chosen, "/chosen", "linux,iommu-force-on",
                             NULL, 0);

        if (prom_tce_alloc_start) {
                prom_setprop(prom.chosen, "/chosen", "linux,tce-alloc-start",
                             &prom_tce_alloc_start,
                             sizeof(prom_tce_alloc_start));
                prom_setprop(prom.chosen, "/chosen", "linux,tce-alloc-end",
                             &prom_tce_alloc_end,
                             sizeof(prom_tce_alloc_end));
        }
#endif

        /*
         * Fixup any known bugs in the device-tree
         */
        fixup_device_tree();

        /*
         * Now finally create the flattened device-tree
         */
        prom_printf("copying OF device tree...\n");
        flatten_device_tree();

        /*
         * in case stdin is USB and still active on IBM machines...
         * Unfortunately quiesce crashes on some powermacs if we have
         * closed stdin already (in particular the powerbook 101).
         */
        if (of_platform != PLATFORM_POWERMAC)
                prom_close_stdin();

        /*
         * Call OF "quiesce" method to shut down pending DMA's from
         * devices etc...
         */
        prom_printf("Quiescing Open Firmware ...\n");
        call_prom("quiesce", 0, 0);

        /*
         * And finally, call the kernel passing it the flattened device
         * tree and NULL as r5, thus triggering the new entry point which
         * is common to us and kexec
         */
        hdr = dt_header_start;

        prom_printf("Booting Linux via __start() @ 0x%lx ...\n", kbase);
        prom_debug("->dt_header_start=0x%lx\n", hdr);

#ifdef CONFIG_PPC32
        reloc_got2(-offset);
#endif

        /* Move to secure memory if we're supposed to be secure guests. */
        setup_secure_guest(kbase, hdr);

        __start(hdr, kbase, 0, 0, 0, 0, 0);

        return 0;
}