/*
 * Copyright (C) 2000, 2001, 2002, 2003 Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/linkage.h>
#include <linux/mm.h>
#include <linux/blkdev.h>
#include <linux/bootmem.h>
#include <linux/pm.h>
#include <linux/smp.h>

#include <asm/bootinfo.h>
#include <asm/reboot.h>
#include <asm/sibyte/board.h>

#include <asm/fw/cfe/cfe_api.h>
#include <asm/fw/cfe/cfe_error.h>

/* Max ram addressable in 32-bit segments */
#ifdef CONFIG_64BIT
#define MAX_RAM_SIZE (~0ULL)
#else
#ifdef CONFIG_HIGHMEM
#ifdef CONFIG_64BIT_PHYS_ADDR
#define MAX_RAM_SIZE (~0ULL)
#else
#define MAX_RAM_SIZE (0xffffffffULL)
#endif
#else
#define MAX_RAM_SIZE (0x1fffffffULL)
#endif
#endif

#define SIBYTE_MAX_MEM_REGIONS 8
phys_t board_mem_region_addrs[SIBYTE_MAX_MEM_REGIONS];
phys_t board_mem_region_sizes[SIBYTE_MAX_MEM_REGIONS];
unsigned int board_mem_region_count;

int cfe_cons_handle;

#ifdef CONFIG_BLK_DEV_INITRD
extern unsigned long initrd_start, initrd_end;
#endif

#ifdef CONFIG_KGDB
extern int kgdb_port;
#endif

static void __noreturn cfe_linux_exit(void *arg)
{
        int warm = *(int *)arg;

        if (smp_processor_id()) {
                static int reboot_smp;

                /* Don't repeat the process from another CPU */
                if (!reboot_smp) {
                        /* Get CPU 0 to do the cfe_exit */
                        reboot_smp = 1;
                        smp_call_function(cfe_linux_exit, arg, 1, 0);
                }
        } else {
                printk("Passing control back to CFE...\n");
                cfe_exit(warm, 0);
                printk("cfe_exit returned??\n");
        }
        while (1);
}

static void __noreturn cfe_linux_restart(char *command)
{
        static const int zero;

        cfe_linux_exit((void *)&zero);
}

static void __noreturn cfe_linux_halt(void)
{
        static const int one = 1;

        cfe_linux_exit((void *)&one);
}

static __init void prom_meminit(void)
{
        u64 addr, size, type; /* regardless of 64BIT_PHYS_ADDR */
        int mem_flags = 0;
        unsigned int idx;
        int rd_flag;
#ifdef CONFIG_BLK_DEV_INITRD
        unsigned long initrd_pstart;
        unsigned long initrd_pend;

        initrd_pstart = CPHYSADDR(initrd_start);
        initrd_pend = CPHYSADDR(initrd_end);
        if (initrd_start &&
            ((initrd_pstart > MAX_RAM_SIZE)
             || (initrd_pend > MAX_RAM_SIZE))) {
                panic("initrd out of addressable memory");
        }

#endif /* INITRD */

        for (idx = 0; cfe_enummem(idx, mem_flags, &addr, &size, &type) != CFE_ERR_NOMORE;
             idx++) {
                rd_flag = 0;
                if (type == CFE_MI_AVAILABLE) {
                        /*
                         * See if this block contains (any portion of) the
                         * ramdisk
                         */
#ifdef CONFIG_BLK_DEV_INITRD
                        if (initrd_start) {
                                if ((initrd_pstart > addr) &&
                                    (initrd_pstart < (addr + size))) {
                                        add_memory_region(addr,
                                                          initrd_pstart - addr,
                                                          BOOT_MEM_RAM);
                                        rd_flag = 1;
                                }
                                if ((initrd_pend > addr) &&
                                    (initrd_pend < (addr + size))) {
                                        add_memory_region(initrd_pend,
                                                (addr + size) - initrd_pend,
                                                 BOOT_MEM_RAM);
                                        rd_flag = 1;
                                }
                        }
#endif
                        if (!rd_flag) {
                                if (addr > MAX_RAM_SIZE)
                                        continue;
                                if (addr+size > MAX_RAM_SIZE)
                                        size = MAX_RAM_SIZE - (addr+size) + 1;
                                /*
                                 * memcpy/__copy_user prefetch, which
                                 * will cause a bus error for
                                 * KSEG/KUSEG addrs not backed by RAM.
                                 * Hence, reserve some padding for the
                                 * prefetch distance.
                                 */
                                if (size > 512)
                                        size -= 512;
                                add_memory_region(addr, size, BOOT_MEM_RAM);
                        }
                        board_mem_region_addrs[board_mem_region_count] = addr;
                        board_mem_region_sizes[board_mem_region_count] = size;
                        board_mem_region_count++;
                        if (board_mem_region_count ==
                            SIBYTE_MAX_MEM_REGIONS) {
                                /*
                                 * Too many regions.  Need to configure more
                                 */
                                while(1);
                        }
                }
        }
#ifdef CONFIG_BLK_DEV_INITRD
        if (initrd_start) {
                add_memory_region(initrd_pstart, initrd_pend - initrd_pstart,
                                  BOOT_MEM_RESERVED);
        }
#endif
}

#ifdef CONFIG_BLK_DEV_INITRD
static int __init initrd_setup(char *str)
{
        char rdarg[64];
        int idx;
        char *tmp, *endptr;
        unsigned long initrd_size;

        /* Make a copy of the initrd argument so we can smash it up here */
        for (idx = 0; idx < sizeof(rdarg)-1; idx++) {
                if (!str[idx] || (str[idx] == ' ')) break;
                rdarg[idx] = str[idx];
        }

        rdarg[idx] = 0;
        str = rdarg;

        /*
         *Initrd location comes in the form "<hex size of ramdisk in bytes>@<location in memory>"
         *  e.g. initrd=3abfd@80010000.  This is set up by the loader.
         */
        for (tmp = str; *tmp != '@'; tmp++) {
                if (!*tmp) {
                        goto fail;
                }
        }
        *tmp = 0;
        tmp++;
        if (!*tmp) {
                goto fail;
        }
        initrd_size = simple_strtoul(str, &endptr, 16);
        if (*endptr) {
                *(tmp-1) = '@';
                goto fail;
        }
        *(tmp-1) = '@';
        initrd_start = simple_strtoul(tmp, &endptr, 16);
        if (*endptr) {
                goto fail;
        }
        initrd_end = initrd_start + initrd_size;
        printk("Found initrd of %lx@%lx\n", initrd_size, initrd_start);
        return 1;
 fail:
        printk("Bad initrd argument.  Disabling initrd\n");
        initrd_start = 0;
        initrd_end = 0;
        return 1;
}

#endif

/*
 * prom_init is called just after the cpu type is determined, from setup_arch()
 */
void __init prom_init(void)
{
        uint64_t cfe_ept, cfe_handle;
        unsigned int cfe_eptseal;
        int argc = fw_arg0;
        char **envp = (char **) fw_arg2;
        int *prom_vec = (int *) fw_arg3;
#ifdef CONFIG_KGDB
        char *arg;
#endif

        _machine_restart   = cfe_linux_restart;
        _machine_halt      = cfe_linux_halt;
        pm_power_off = cfe_linux_halt;

        /*
         * Check if a loader was used; if NOT, the 4 arguments are
         * what CFE gives us (handle, 0, EPT and EPTSEAL)
         */
        if (argc < 0) {
                cfe_handle = (uint64_t)(long)argc;
                cfe_ept = (long)envp;
                cfe_eptseal = (uint32_t)(unsigned long)prom_vec;
        } else {
                if ((int32_t)(long)prom_vec < 0) {
                        /*
                         * Old loader; all it gives us is the handle,
                         * so use the "known" entrypoint and assume
                         * the seal.
                         */
                        cfe_handle = (uint64_t)(long)prom_vec;
                        cfe_ept = (uint64_t)((int32_t)0x9fc00500);
                        cfe_eptseal = CFE_EPTSEAL;
                } else {
                        /*
                         * Newer loaders bundle the handle/ept/eptseal
                         * Note: prom_vec is in the loader's useg
                         * which is still alive in the TLB.
                         */
                        cfe_handle = (uint64_t)((int32_t *)prom_vec)[0];
                        cfe_ept = (uint64_t)((int32_t *)prom_vec)[2];
                        cfe_eptseal = (unsigned int)((uint32_t *)prom_vec)[3];
                }
        }
        if (cfe_eptseal != CFE_EPTSEAL) {
                /* too early for panic to do any good */
                printk("CFE's entrypoint seal doesn't match. Spinning.");
                while (1) ;
        }
        cfe_init(cfe_handle, cfe_ept);
        /*
         * Get the handle for (at least) prom_putchar, possibly for
         * boot console
         */
        cfe_cons_handle = cfe_getstdhandle(CFE_STDHANDLE_CONSOLE);
        if (cfe_getenv("LINUX_CMDLINE", arcs_cmdline, CL_SIZE) < 0) {
                if (argc < 0) {
                        /*
                         * It's OK for direct boot to not provide a
                         *  command line
                         */
                        strcpy(arcs_cmdline, "root=/dev/ram0 ");
#ifdef CONFIG_SIBYTE_PTSWARM
                        strcat(arcs_cmdline, "console=ttyS0,115200 ");
#endif
                } else {
                        /* The loader should have set the command line */
                        /* too early for panic to do any good */
                        printk("LINUX_CMDLINE not defined in cfe.");
                        while (1) ;
                }
        }

#ifdef CONFIG_KGDB
        if ((arg = strstr(arcs_cmdline, "kgdb=duart")) != NULL)
                kgdb_port = (arg[10] == '0') ? 0 : 1;
        else
                kgdb_port = 1;
#endif

#ifdef CONFIG_BLK_DEV_INITRD
        {
                char *ptr;
                /* Need to find out early whether we've got an initrd.  So scan
                   the list looking now */
                for (ptr = arcs_cmdline; *ptr; ptr++) {
                        while (*ptr == ' ') {
                                ptr++;
                        }
                        if (!strncmp(ptr, "initrd=", 7)) {
                                initrd_setup(ptr+7);
                                break;
                        } else {
                                while (*ptr && (*ptr != ' ')) {
                                        ptr++;
                                }
                        }
                }
        }
#endif /* CONFIG_BLK_DEV_INITRD */

        /* Not sure this is needed, but it's the safe way. */
        arcs_cmdline[CL_SIZE-1] = 0;

        prom_meminit();
}

void __init prom_free_prom_memory(void)
{
        /* Not sure what I'm supposed to do here.  Nothing, I think */
}

void prom_putchar(char c)
{
        int ret;

        while ((ret = cfe_write(cfe_cons_handle, &c, 1)) == 0)
                ;
}