/*
 * 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 <linux/export.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 <asm/trace.h>
#include <asm/firmware.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);

void vpa_init(int cpu)
{
        int hwcpu = get_hard_smp_processor_id(cpu);
        unsigned long addr;
        long ret;
        struct paca_struct *pp;
        struct dtl_entry *dtl;

        if (cpu_has_feature(CPU_FTR_ALTIVEC))
                lppaca_of(cpu).vmxregs_in_use = 1;

        addr = __pa(&lppaca_of(cpu));
        ret = register_vpa(hwcpu, addr);

        if (ret) {
                pr_err("WARNING: VPA registration for cpu %d (hw %d) of area "
                       "%lx failed with %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)
                        pr_err("WARNING: SLB shadow buffer registration for "
                               "cpu %d (hw %d) of area %lx failed with %ld\n",
                               cpu, hwcpu, addr, ret);
        }

        /*
         * Register dispatch trace log, if one has been allocated.
         */
        pp = &paca[cpu];
        dtl = pp->dispatch_log;
        if (dtl) {
                pp->dtl_ridx = 0;
                pp->dtl_curr = dtl;
                lppaca_of(cpu).dtl_idx = 0;

                /* hypervisor reads buffer length from this field */
                dtl->enqueue_to_dispatch_time = DISPATCH_LOG_BYTES;
                ret = register_dtl(hwcpu, __pa(dtl));
                if (ret)
                        pr_err("WARNING: DTL registration of cpu %d (hw %d) "
                               "failed with %ld\n", smp_processor_id(),
                               hwcpu, ret);
                lppaca_of(cpu).dtl_enable_mask = 2;
        }
}

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;
        if (firmware_has_feature(FW_FEATURE_XCMO) && !(hpte_r & HPTE_R_N))
                flags |= H_COALESCE_CAND;

        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;
        struct {
                unsigned long pteh;
                unsigned long ptel;
        } ptes[4];
        long lpar_rc;
        unsigned long i, j;

        /* Read in batches of 4,
         * invalidate only valid entries not in the VRMA
         * hpte_count will be a multiple of 4
         */
        for (i = 0; i < hpte_count; i += 4) {
                lpar_rc = plpar_pte_read_4_raw(0, i, (void *)ptes);
                if (lpar_rc != H_SUCCESS)
                        continue;
                for (j = 0; j < 4; j++){
                        if ((ptes[j].pteh & HPTE_V_VRMA_MASK) ==
                                HPTE_V_VRMA_MASK)
                                continue;
                        if (ptes[j].pteh & HPTE_V_VALID)
                                plpar_pte_remove_raw(0, i + j, 0,
                                        &(ptes[j].pteh), &(ptes[j].ptel));
                }
        }
}

/*
 * 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 = !mmu_has_feature(MMU_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);
}

static int __init disable_bulk_remove(char *str)
{
        if (strcmp(str, "off") == 0 &&
            firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
                        printk(KERN_INFO "Disabling BULK_REMOVE firmware feature");
                        powerpc_firmware_features &= ~FW_FEATURE_BULK_REMOVE;
        }
        return 1;
}

__setup("bulk_remove=", disable_bulk_remove);

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

#ifdef CONFIG_TRACEPOINTS
/*
 * We optimise our hcall path by placing hcall_tracepoint_refcount
 * directly in the TOC so we can check if the hcall tracepoints are
 * enabled via a single load.
 */

/* NB: reg/unreg are called while guarded with the tracepoints_mutex */
extern long hcall_tracepoint_refcount;

/* 
 * Since the tracing code might execute hcalls we need to guard against
 * recursion. One example of this are spinlocks calling H_YIELD on
 * shared processor partitions.
 */
static DEFINE_PER_CPU(unsigned int, hcall_trace_depth);

void hcall_tracepoint_regfunc(void)
{
        hcall_tracepoint_refcount++;
}

void hcall_tracepoint_unregfunc(void)
{
        hcall_tracepoint_refcount--;
}

void __trace_hcall_entry(unsigned long opcode, unsigned long *args)
{
        unsigned long flags;
        unsigned int *depth;

        /*
         * We cannot call tracepoints inside RCU idle regions which
         * means we must not trace H_CEDE.
         */
        if (opcode == H_CEDE)
                return;

        local_irq_save(flags);

        depth = &__get_cpu_var(hcall_trace_depth);

        if (*depth)
                goto out;

        (*depth)++;
        preempt_disable();
        trace_hcall_entry(opcode, args);
        (*depth)--;

out:
        local_irq_restore(flags);
}

void __trace_hcall_exit(long opcode, unsigned long retval,
                        unsigned long *retbuf)
{
        unsigned long flags;
        unsigned int *depth;

        if (opcode == H_CEDE)
                return;

        local_irq_save(flags);

        depth = &__get_cpu_var(hcall_trace_depth);

        if (*depth)
                goto out;

        (*depth)++;
        trace_hcall_exit(opcode, retval, retbuf);
        preempt_enable();
        (*depth)--;

out:
        local_irq_restore(flags);
}
#endif

/**
 * h_get_mpp
 * H_GET_MPP hcall returns info in 7 parms
 */
int h_get_mpp(struct hvcall_mpp_data *mpp_data)
{
        int rc;
        unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];

        rc = plpar_hcall9(H_GET_MPP, retbuf);

        mpp_data->entitled_mem = retbuf[0];
        mpp_data->mapped_mem = retbuf[1];

        mpp_data->group_num = (retbuf[2] >> 2 * 8) & 0xffff;
        mpp_data->pool_num = retbuf[2] & 0xffff;

        mpp_data->mem_weight = (retbuf[3] >> 7 * 8) & 0xff;
        mpp_data->unallocated_mem_weight = (retbuf[3] >> 6 * 8) & 0xff;
        mpp_data->unallocated_entitlement = retbuf[3] & 0xffffffffffff;

        mpp_data->pool_size = retbuf[4];
        mpp_data->loan_request = retbuf[5];
        mpp_data->backing_mem = retbuf[6];

        return rc;
}
EXPORT_SYMBOL(h_get_mpp);

int h_get_mpp_x(struct hvcall_mpp_x_data *mpp_x_data)
{
        int rc;
        unsigned long retbuf[PLPAR_HCALL9_BUFSIZE] = { 0 };

        rc = plpar_hcall9(H_GET_MPP_X, retbuf);

        mpp_x_data->coalesced_bytes = retbuf[0];
        mpp_x_data->pool_coalesced_bytes = retbuf[1];
        mpp_x_data->pool_purr_cycles = retbuf[2];
        mpp_x_data->pool_spurr_cycles = retbuf[3];

        return rc;
}