/*
 * pSeries_lpar.c
 * Copyright (C) 2001 Todd Inglett, IBM Corporation
 *
 * pSeries LPAR support.
 * 
 * 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
 */

/* Enables debugging of low-level hash table routines - careful! */
#undef DEBUG

#include <linux/kernel.h>
#include <linux/dma-mapping.h>
#include <linux/console.h>
#include <asm/processor.h>
#include <asm/mmu.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/machdep.h>
#include <asm/abs_addr.h>
#include <asm/mmu_context.h>
#include <asm/iommu.h>
#include <asm/tlbflush.h>
#include <asm/tlb.h>
#include <asm/prom.h>
#include <asm/cputable.h>
#include <asm/udbg.h>
#include <asm/smp.h>

#include "plpar_wrappers.h"
#include "pseries.h"


/* in hvCall.S */
EXPORT_SYMBOL(plpar_hcall);
EXPORT_SYMBOL(plpar_hcall9);
EXPORT_SYMBOL(plpar_hcall_norets);

extern void pSeries_find_serial_port(void);


static int vtermno;     /* virtual terminal# for udbg  */

#define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
static void udbg_hvsi_putc(char c)
{
        /* packet's seqno isn't used anyways */
        uint8_t packet[] __ALIGNED__ = { 0xff, 5, 0, 0, c };
        int rc;

        if (c == '\n')
                udbg_hvsi_putc('\r');

        do {
                rc = plpar_put_term_char(vtermno, sizeof(packet), packet);
        } while (rc == H_BUSY);
}

static long hvsi_udbg_buf_len;
static uint8_t hvsi_udbg_buf[256];

static int udbg_hvsi_getc_poll(void)
{
        unsigned char ch;
        int rc, i;

        if (hvsi_udbg_buf_len == 0) {
                rc = plpar_get_term_char(vtermno, &hvsi_udbg_buf_len, hvsi_udbg_buf);
                if (rc != H_SUCCESS || hvsi_udbg_buf[0] != 0xff) {
                        /* bad read or non-data packet */
                        hvsi_udbg_buf_len = 0;
                } else {
                        /* remove the packet header */
                        for (i = 4; i < hvsi_udbg_buf_len; i++)
                                hvsi_udbg_buf[i-4] = hvsi_udbg_buf[i];
                        hvsi_udbg_buf_len -= 4;
                }
        }

        if (hvsi_udbg_buf_len <= 0 || hvsi_udbg_buf_len > 256) {
                /* no data ready */
                hvsi_udbg_buf_len = 0;
                return -1;
        }

        ch = hvsi_udbg_buf[0];
        /* shift remaining data down */
        for (i = 1; i < hvsi_udbg_buf_len; i++) {
                hvsi_udbg_buf[i-1] = hvsi_udbg_buf[i];
        }
        hvsi_udbg_buf_len--;

        return ch;
}

static int udbg_hvsi_getc(void)
{
        int ch;
        for (;;) {
                ch = udbg_hvsi_getc_poll();
                if (ch == -1) {
                        /* This shouldn't be needed...but... */
                        volatile unsigned long delay;
                        for (delay=0; delay < 2000000; delay++)
                                ;
                } else {
                        return ch;
                }
        }
}

static void udbg_putcLP(char c)
{
        char buf[16];
        unsigned long rc;

        if (c == '\n')
                udbg_putcLP('\r');

        buf[0] = c;
        do {
                rc = plpar_put_term_char(vtermno, 1, buf);
        } while(rc == H_BUSY);
}

/* Buffered chars getc */
static long inbuflen;
static long inbuf[2];   /* must be 2 longs */

static int udbg_getc_pollLP(void)
{
        /* The interface is tricky because it may return up to 16 chars.
         * We save them statically for future calls to udbg_getc().
         */
        char ch, *buf = (char *)inbuf;
        int i;
        long rc;
        if (inbuflen == 0) {
                /* get some more chars. */
                inbuflen = 0;
                rc = plpar_get_term_char(vtermno, &inbuflen, buf);
                if (rc != H_SUCCESS)
                        inbuflen = 0;   /* otherwise inbuflen is garbage */
        }
        if (inbuflen <= 0 || inbuflen > 16) {
                /* Catch error case as well as other oddities (corruption) */
                inbuflen = 0;
                return -1;
        }
        ch = buf[0];
        for (i = 1; i < inbuflen; i++)  /* shuffle them down. */
                buf[i-1] = buf[i];
        inbuflen--;
        return ch;
}

static int udbg_getcLP(void)
{
        int ch;
        for (;;) {
                ch = udbg_getc_pollLP();
                if (ch == -1) {
                        /* This shouldn't be needed...but... */
                        volatile unsigned long delay;
                        for (delay=0; delay < 2000000; delay++)
                                ;
                } else {
                        return ch;
                }
        }
}

/* call this from early_init() for a working debug console on
 * vterm capable LPAR machines
 */
void __init udbg_init_debug_lpar(void)
{
        vtermno = 0;
        udbg_putc = udbg_putcLP;
        udbg_getc = udbg_getcLP;
        udbg_getc_poll = udbg_getc_pollLP;

        register_early_udbg_console();
}

/* returns 0 if couldn't find or use /chosen/stdout as console */
void __init find_udbg_vterm(void)
{
        struct device_node *stdout_node;
        const u32 *termno;
        const char *name;

        /* find the boot console from /chosen/stdout */
        if (!of_chosen)
                return;
        name = of_get_property(of_chosen, "linux,stdout-path", NULL);
        if (name == NULL)
                return;
        stdout_node = of_find_node_by_path(name);
        if (!stdout_node)
                return;
        name = of_get_property(stdout_node, "name", NULL);
        if (!name) {
                printk(KERN_WARNING "stdout node missing 'name' property!\n");
                goto out;
        }

        /* Check if it's a virtual terminal */
        if (strncmp(name, "vty", 3) != 0)
                goto out;
        termno = of_get_property(stdout_node, "reg", NULL);
        if (termno == NULL)
                goto out;
        vtermno = termno[0];

        if (of_device_is_compatible(stdout_node, "hvterm1")) {
                udbg_putc = udbg_putcLP;
                udbg_getc = udbg_getcLP;
                udbg_getc_poll = udbg_getc_pollLP;
                add_preferred_console("hvc", termno[0] & 0xff, NULL);
        } else if (of_device_is_compatible(stdout_node, "hvterm-protocol")) {
                vtermno = termno[0];
                udbg_putc = udbg_hvsi_putc;
                udbg_getc = udbg_hvsi_getc;
                udbg_getc_poll = udbg_hvsi_getc_poll;
                add_preferred_console("hvsi", termno[0] & 0xff, NULL);
        }
out:
        of_node_put(stdout_node);
}

void vpa_init(int cpu)
{
        int hwcpu = get_hard_smp_processor_id(cpu);
        unsigned long addr;
        long ret;

        if (cpu_has_feature(CPU_FTR_ALTIVEC))
                lppaca[cpu].vmxregs_in_use = 1;

        addr = __pa(&lppaca[cpu]);
        ret = register_vpa(hwcpu, addr);

        if (ret) {
                printk(KERN_ERR "WARNING: vpa_init: VPA registration for "
                                "cpu %d (hw %d) of area %lx returns %ld\n",
                                cpu, hwcpu, addr, ret);
                return;
        }
        /*
         * PAPR says this feature is SLB-Buffer but firmware never
         * reports that.  All SPLPAR support SLB shadow buffer.
         */
        addr = __pa(&slb_shadow[cpu]);
        if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
                ret = register_slb_shadow(hwcpu, addr);
                if (ret)
                        printk(KERN_ERR
                               "WARNING: vpa_init: SLB shadow buffer "
                               "registration for cpu %d (hw %d) of area %lx "
                               "returns %ld\n", cpu, hwcpu, addr, ret);
        }
}

static long pSeries_lpar_hpte_insert(unsigned long hpte_group,
                              unsigned long va, unsigned long pa,
                              unsigned long rflags, unsigned long vflags,
                              int psize, int ssize)
{
        unsigned long lpar_rc;
        unsigned long flags;
        unsigned long slot;
        unsigned long hpte_v, hpte_r;

        if (!(vflags & HPTE_V_BOLTED))
                pr_devel("hpte_insert(group=%lx, va=%016lx, pa=%016lx, "
                         "rflags=%lx, vflags=%lx, psize=%d)\n",
                         hpte_group, va, pa, rflags, vflags, psize);

        hpte_v = hpte_encode_v(va, psize, ssize) | vflags | HPTE_V_VALID;
        hpte_r = hpte_encode_r(pa, psize) | rflags;

        if (!(vflags & HPTE_V_BOLTED))
                pr_devel(" hpte_v=%016lx, hpte_r=%016lx\n", hpte_v, hpte_r);

        /* Now fill in the actual HPTE */
        /* Set CEC cookie to 0         */
        /* Zero page = 0               */
        /* I-cache Invalidate = 0      */
        /* I-cache synchronize = 0     */
        /* Exact = 0                   */
        flags = 0;

        /* Make pHyp happy */
        if ((rflags & _PAGE_NO_CACHE) & !(rflags & _PAGE_WRITETHRU))
                hpte_r &= ~_PAGE_COHERENT;

        lpar_rc = plpar_pte_enter(flags, hpte_group, hpte_v, hpte_r, &slot);
        if (unlikely(lpar_rc == H_PTEG_FULL)) {
                if (!(vflags & HPTE_V_BOLTED))
                        pr_devel(" full\n");
                return -1;
        }

        /*
         * Since we try and ioremap PHBs we don't own, the pte insert
         * will fail. However we must catch the failure in hash_page
         * or we will loop forever, so return -2 in this case.
         */
        if (unlikely(lpar_rc != H_SUCCESS)) {
                if (!(vflags & HPTE_V_BOLTED))
                        pr_devel(" lpar err %lu\n", lpar_rc);
                return -2;
        }
        if (!(vflags & HPTE_V_BOLTED))
                pr_devel(" -> slot: %lu\n", slot & 7);

        /* Because of iSeries, we have to pass down the secondary
         * bucket bit here as well
         */
        return (slot & 7) | (!!(vflags & HPTE_V_SECONDARY) << 3);
}

static DEFINE_SPINLOCK(pSeries_lpar_tlbie_lock);

static long pSeries_lpar_hpte_remove(unsigned long hpte_group)
{
        unsigned long slot_offset;
        unsigned long lpar_rc;
        int i;
        unsigned long dummy1, dummy2;

        /* pick a random slot to start at */
        slot_offset = mftb() & 0x7;

        for (i = 0; i < HPTES_PER_GROUP; i++) {

                /* don't remove a bolted entry */
                lpar_rc = plpar_pte_remove(H_ANDCOND, hpte_group + slot_offset,
                                           (0x1UL << 4), &dummy1, &dummy2);
                if (lpar_rc == H_SUCCESS)
                        return i;
                BUG_ON(lpar_rc != H_NOT_FOUND);

                slot_offset++;
                slot_offset &= 0x7;
        }

        return -1;
}

static void pSeries_lpar_hptab_clear(void)
{
        unsigned long size_bytes = 1UL << ppc64_pft_size;
        unsigned long hpte_count = size_bytes >> 4;
        unsigned long dummy1, dummy2, dword0;
        long lpar_rc;
        int i;

        /* TODO: Use bulk call */
        for (i = 0; i < hpte_count; i++) {
                /* dont remove HPTEs with VRMA mappings */
                lpar_rc = plpar_pte_remove_raw(H_ANDCOND, i, HPTE_V_1TB_SEG,
                                                &dummy1, &dummy2);
                if (lpar_rc == H_NOT_FOUND) {
                        lpar_rc = plpar_pte_read_raw(0, i, &dword0, &dummy1);
                        if (!lpar_rc && ((dword0 & HPTE_V_VRMA_MASK)
                                != HPTE_V_VRMA_MASK))
                                /* Can be hpte for 1TB Seg. So remove it */
                                plpar_pte_remove_raw(0, i, 0, &dummy1, &dummy2);
                }
        }
}

/*
 * This computes the AVPN and B fields of the first dword of a HPTE,
 * for use when we want to match an existing PTE.  The bottom 7 bits
 * of the returned value are zero.
 */
static inline unsigned long hpte_encode_avpn(unsigned long va, int psize,
                                             int ssize)
{
        unsigned long v;

        v = (va >> 23) & ~(mmu_psize_defs[psize].avpnm);
        v <<= HPTE_V_AVPN_SHIFT;
        v |= ((unsigned long) ssize) << HPTE_V_SSIZE_SHIFT;
        return v;
}

/*
 * NOTE: for updatepp ops we are fortunate that the linux "newpp" bits and
 * the low 3 bits of flags happen to line up.  So no transform is needed.
 * We can probably optimize here and assume the high bits of newpp are
 * already zero.  For now I am paranoid.
 */
static long pSeries_lpar_hpte_updatepp(unsigned long slot,
                                       unsigned long newpp,
                                       unsigned long va,
                                       int psize, int ssize, int local)
{
        unsigned long lpar_rc;
        unsigned long flags = (newpp & 7) | H_AVPN;
        unsigned long want_v;

        want_v = hpte_encode_avpn(va, psize, ssize);

        pr_devel("    update: avpnv=%016lx, hash=%016lx, f=%lx, psize: %d ...",
                 want_v, slot, flags, psize);

        lpar_rc = plpar_pte_protect(flags, slot, want_v);

        if (lpar_rc == H_NOT_FOUND) {
                pr_devel("not found !\n");
                return -1;
        }

        pr_devel("ok\n");

        BUG_ON(lpar_rc != H_SUCCESS);

        return 0;
}

static unsigned long pSeries_lpar_hpte_getword0(unsigned long slot)
{
        unsigned long dword0;
        unsigned long lpar_rc;
        unsigned long dummy_word1;
        unsigned long flags;

        /* Read 1 pte at a time                        */
        /* Do not need RPN to logical page translation */
        /* No cross CEC PFT access                     */
        flags = 0;

        lpar_rc = plpar_pte_read(flags, slot, &dword0, &dummy_word1);

        BUG_ON(lpar_rc != H_SUCCESS);

        return dword0;
}

static long pSeries_lpar_hpte_find(unsigned long va, int psize, int ssize)
{
        unsigned long hash;
        unsigned long i;
        long slot;
        unsigned long want_v, hpte_v;

        hash = hpt_hash(va, mmu_psize_defs[psize].shift, ssize);
        want_v = hpte_encode_avpn(va, psize, ssize);

        /* Bolted entries are always in the primary group */
        slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
        for (i = 0; i < HPTES_PER_GROUP; i++) {
                hpte_v = pSeries_lpar_hpte_getword0(slot);

                if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID))
                        /* HPTE matches */
                        return slot;
                ++slot;
        }

        return -1;
} 

static void pSeries_lpar_hpte_updateboltedpp(unsigned long newpp,
                                             unsigned long ea,
                                             int psize, int ssize)
{
        unsigned long lpar_rc, slot, vsid, va, flags;

        vsid = get_kernel_vsid(ea, ssize);
        va = hpt_va(ea, vsid, ssize);

        slot = pSeries_lpar_hpte_find(va, psize, ssize);
        BUG_ON(slot == -1);

        flags = newpp & 7;
        lpar_rc = plpar_pte_protect(flags, slot, 0);

        BUG_ON(lpar_rc != H_SUCCESS);
}

static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long va,
                                         int psize, int ssize, int local)
{
        unsigned long want_v;
        unsigned long lpar_rc;
        unsigned long dummy1, dummy2;

        pr_devel("    inval : slot=%lx, va=%016lx, psize: %d, local: %d\n",
                 slot, va, psize, local);

        want_v = hpte_encode_avpn(va, psize, ssize);
        lpar_rc = plpar_pte_remove(H_AVPN, slot, want_v, &dummy1, &dummy2);
        if (lpar_rc == H_NOT_FOUND)
                return;

        BUG_ON(lpar_rc != H_SUCCESS);
}

static void pSeries_lpar_hpte_removebolted(unsigned long ea,
                                           int psize, int ssize)
{
        unsigned long slot, vsid, va;

        vsid = get_kernel_vsid(ea, ssize);
        va = hpt_va(ea, vsid, ssize);

        slot = pSeries_lpar_hpte_find(va, psize, ssize);
        BUG_ON(slot == -1);

        pSeries_lpar_hpte_invalidate(slot, va, psize, ssize, 0);
}

/* Flag bits for H_BULK_REMOVE */
#define HBR_REQUEST     0x4000000000000000UL
#define HBR_RESPONSE    0x8000000000000000UL
#define HBR_END         0xc000000000000000UL
#define HBR_AVPN        0x0200000000000000UL
#define HBR_ANDCOND     0x0100000000000000UL

/*
 * Take a spinlock around flushes to avoid bouncing the hypervisor tlbie
 * lock.
 */
static void pSeries_lpar_flush_hash_range(unsigned long number, int local)
{
        unsigned long i, pix, rc;
        unsigned long flags = 0;
        struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
        int lock_tlbie = !cpu_has_feature(CPU_FTR_LOCKLESS_TLBIE);
        unsigned long param[9];
        unsigned long va;
        unsigned long hash, index, shift, hidx, slot;
        real_pte_t pte;
        int psize, ssize;

        if (lock_tlbie)
                spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);

        psize = batch->psize;
        ssize = batch->ssize;
        pix = 0;
        for (i = 0; i < number; i++) {
                va = batch->vaddr[i];
                pte = batch->pte[i];
                pte_iterate_hashed_subpages(pte, psize, va, index, shift) {
                        hash = hpt_hash(va, shift, ssize);
                        hidx = __rpte_to_hidx(pte, index);
                        if (hidx & _PTEIDX_SECONDARY)
                                hash = ~hash;
                        slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
                        slot += hidx & _PTEIDX_GROUP_IX;
                        if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
                                pSeries_lpar_hpte_invalidate(slot, va, psize,
                                                             ssize, local);
                        } else {
                                param[pix] = HBR_REQUEST | HBR_AVPN | slot;
                                param[pix+1] = hpte_encode_avpn(va, psize,
                                                                ssize);
                                pix += 2;
                                if (pix == 8) {
                                        rc = plpar_hcall9(H_BULK_REMOVE, param,
                                                param[0], param[1], param[2],
                                                param[3], param[4], param[5],
                                                param[6], param[7]);
                                        BUG_ON(rc != H_SUCCESS);
                                        pix = 0;
                                }
                        }
                } pte_iterate_hashed_end();
        }
        if (pix) {
                param[pix] = HBR_END;
                rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
                                  param[2], param[3], param[4], param[5],
                                  param[6], param[7]);
                BUG_ON(rc != H_SUCCESS);
        }

        if (lock_tlbie)
                spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
}

void __init hpte_init_lpar(void)
{
        ppc_md.hpte_invalidate  = pSeries_lpar_hpte_invalidate;
        ppc_md.hpte_updatepp    = pSeries_lpar_hpte_updatepp;
        ppc_md.hpte_updateboltedpp = pSeries_lpar_hpte_updateboltedpp;
        ppc_md.hpte_insert      = pSeries_lpar_hpte_insert;
        ppc_md.hpte_remove      = pSeries_lpar_hpte_remove;
        ppc_md.hpte_removebolted = pSeries_lpar_hpte_removebolted;
        ppc_md.flush_hash_range = pSeries_lpar_flush_hash_range;
        ppc_md.hpte_clear_all   = pSeries_lpar_hptab_clear;
}

#ifdef CONFIG_PPC_SMLPAR
#define CMO_FREE_HINT_DEFAULT 1
static int cmo_free_hint_flag = CMO_FREE_HINT_DEFAULT;

static int __init cmo_free_hint(char *str)
{
        char *parm;
        parm = strstrip(str);

        if (strcasecmp(parm, "no") == 0 || strcasecmp(parm, "off") == 0) {
                printk(KERN_INFO "cmo_free_hint: CMO free page hinting is not active.\n");
                cmo_free_hint_flag = 0;
                return 1;
        }

        cmo_free_hint_flag = 1;
        printk(KERN_INFO "cmo_free_hint: CMO free page hinting is active.\n");

        if (strcasecmp(parm, "yes") == 0 || strcasecmp(parm, "on") == 0)
                return 1;

        return 0;
}

__setup("cmo_free_hint=", cmo_free_hint);

static void pSeries_set_page_state(struct page *page, int order,
                                   unsigned long state)
{
        int i, j;
        unsigned long cmo_page_sz, addr;

        cmo_page_sz = cmo_get_page_size();
        addr = __pa((unsigned long)page_address(page));

        for (i = 0; i < (1 << order); i++, addr += PAGE_SIZE) {
                for (j = 0; j < PAGE_SIZE; j += cmo_page_sz)
                        plpar_hcall_norets(H_PAGE_INIT, state, addr + j, 0);
        }
}

void arch_free_page(struct page *page, int order)
{
        if (!cmo_free_hint_flag || !firmware_has_feature(FW_FEATURE_CMO))
                return;

        pSeries_set_page_state(page, order, H_PAGE_SET_UNUSED);
}
EXPORT_SYMBOL(arch_free_page);

#endif