// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * native hashtable management.
 *
 * SMP scalability work:
 *    Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
 */

#undef DEBUG_LOW

#include <linux/spinlock.h>
#include <linux/bitops.h>
#include <linux/of.h>
#include <linux/processor.h>
#include <linux/threads.h>
#include <linux/smp.h>
#include <linux/pgtable.h>

#include <asm/machdep.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/trace.h>
#include <asm/tlb.h>
#include <asm/cputable.h>
#include <asm/udbg.h>
#include <asm/kexec.h>
#include <asm/ppc-opcode.h>
#include <asm/feature-fixups.h>

#ifdef DEBUG_LOW
#define DBG_LOW(fmt...) udbg_printf(fmt)
#else
#define DBG_LOW(fmt...)
#endif

#ifdef __BIG_ENDIAN__
#define HPTE_LOCK_BIT 3
#else
#define HPTE_LOCK_BIT (56+3)
#endif

static DEFINE_RAW_SPINLOCK(native_tlbie_lock);

#ifdef CONFIG_LOCKDEP
static struct lockdep_map hpte_lock_map =
        STATIC_LOCKDEP_MAP_INIT("hpte_lock", &hpte_lock_map);

static void acquire_hpte_lock(void)
{
        lock_map_acquire(&hpte_lock_map);
}

static void release_hpte_lock(void)
{
        lock_map_release(&hpte_lock_map);
}
#else
static void acquire_hpte_lock(void)
{
}

static void release_hpte_lock(void)
{
}
#endif

static inline unsigned long  ___tlbie(unsigned long vpn, int psize,
                                                int apsize, int ssize)
{
        unsigned long va;
        unsigned int penc;
        unsigned long sllp;

        /*
         * We need 14 to 65 bits of va for a tlibe of 4K page
         * With vpn we ignore the lower VPN_SHIFT bits already.
         * And top two bits are already ignored because we can
         * only accomodate 76 bits in a 64 bit vpn with a VPN_SHIFT
         * of 12.
         */
        va = vpn << VPN_SHIFT;
        /*
         * clear top 16 bits of 64bit va, non SLS segment
         * Older versions of the architecture (2.02 and earler) require the
         * masking of the top 16 bits.
         */
        if (mmu_has_feature(MMU_FTR_TLBIE_CROP_VA))
                va &= ~(0xffffULL << 48);

        switch (psize) {
        case MMU_PAGE_4K:
                /* clear out bits after (52) [0....52.....63] */
                va &= ~((1ul << (64 - 52)) - 1);
                va |= ssize << 8;
                sllp = get_sllp_encoding(apsize);
                va |= sllp << 5;
                asm volatile(ASM_FTR_IFCLR("tlbie %0,0", PPC_TLBIE(%1,%0), %2)
                             : : "r" (va), "r"(0), "i" (CPU_FTR_ARCH_206)
                             : "memory");
                break;
        default:
                /* We need 14 to 14 + i bits of va */
                penc = mmu_psize_defs[psize].penc[apsize];
                va &= ~((1ul << mmu_psize_defs[apsize].shift) - 1);
                va |= penc << 12;
                va |= ssize << 8;
                /*
                 * AVAL bits:
                 * We don't need all the bits, but rest of the bits
                 * must be ignored by the processor.
                 * vpn cover upto 65 bits of va. (0...65) and we need
                 * 58..64 bits of va.
                 */
                va |= (vpn & 0xfe); /* AVAL */
                va |= 1; /* L */
                asm volatile(ASM_FTR_IFCLR("tlbie %0,1", PPC_TLBIE(%1,%0), %2)
                             : : "r" (va), "r"(0), "i" (CPU_FTR_ARCH_206)
                             : "memory");
                break;
        }
        return va;
}

static inline void fixup_tlbie_vpn(unsigned long vpn, int psize,
                                   int apsize, int ssize)
{
        if (cpu_has_feature(CPU_FTR_P9_TLBIE_ERAT_BUG)) {
                /* Radix flush for a hash guest */

                unsigned long rb,rs,prs,r,ric;

                rb = PPC_BIT(52); /* IS = 2 */
                rs = 0;  /* lpid = 0 */
                prs = 0; /* partition scoped */
                r = 1;   /* radix format */
                ric = 0; /* RIC_FLSUH_TLB */

                /*
                 * Need the extra ptesync to make sure we don't
                 * re-order the tlbie
                 */
                asm volatile("ptesync": : :"memory");
                asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
                             : : "r"(rb), "i"(r), "i"(prs),
                               "i"(ric), "r"(rs) : "memory");
        }


        if (cpu_has_feature(CPU_FTR_P9_TLBIE_STQ_BUG)) {
                /* Need the extra ptesync to ensure we don't reorder tlbie*/
                asm volatile("ptesync": : :"memory");
                ___tlbie(vpn, psize, apsize, ssize);
        }
}

static inline void __tlbie(unsigned long vpn, int psize, int apsize, int ssize)
{
        unsigned long rb;

        rb = ___tlbie(vpn, psize, apsize, ssize);
        trace_tlbie(0, 0, rb, 0, 0, 0, 0);
}

static inline void __tlbiel(unsigned long vpn, int psize, int apsize, int ssize)
{
        unsigned long va;
        unsigned int penc;
        unsigned long sllp;

        /* VPN_SHIFT can be atmost 12 */
        va = vpn << VPN_SHIFT;
        /*
         * clear top 16 bits of 64 bit va, non SLS segment
         * Older versions of the architecture (2.02 and earler) require the
         * masking of the top 16 bits.
         */
        if (mmu_has_feature(MMU_FTR_TLBIE_CROP_VA))
                va &= ~(0xffffULL << 48);

        switch (psize) {
        case MMU_PAGE_4K:
                /* clear out bits after(52) [0....52.....63] */
                va &= ~((1ul << (64 - 52)) - 1);
                va |= ssize << 8;
                sllp = get_sllp_encoding(apsize);
                va |= sllp << 5;
                asm volatile(ASM_FTR_IFSET("tlbiel %0", PPC_TLBIEL_v205(%0, 0), %1)
                             : : "r" (va), "i" (CPU_FTR_ARCH_206)
                             : "memory");
                break;
        default:
                /* We need 14 to 14 + i bits of va */
                penc = mmu_psize_defs[psize].penc[apsize];
                va &= ~((1ul << mmu_psize_defs[apsize].shift) - 1);
                va |= penc << 12;
                va |= ssize << 8;
                /*
                 * AVAL bits:
                 * We don't need all the bits, but rest of the bits
                 * must be ignored by the processor.
                 * vpn cover upto 65 bits of va. (0...65) and we need
                 * 58..64 bits of va.
                 */
                va |= (vpn & 0xfe);
                va |= 1; /* L */
                asm volatile(ASM_FTR_IFSET("tlbiel %0", PPC_TLBIEL_v205(%0, 1), %1)
                             : : "r" (va), "i" (CPU_FTR_ARCH_206)
                             : "memory");
                break;
        }
        trace_tlbie(0, 1, va, 0, 0, 0, 0);

}

static inline void tlbie(unsigned long vpn, int psize, int apsize,
                         int ssize, int local)
{
        unsigned int use_local = local && mmu_has_feature(MMU_FTR_TLBIEL);
        int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);

        if (use_local)
                use_local = mmu_psize_defs[psize].tlbiel;
        if (lock_tlbie && !use_local)
                raw_spin_lock(&native_tlbie_lock);
        asm volatile("ptesync": : :"memory");
        if (use_local) {
                __tlbiel(vpn, psize, apsize, ssize);
                ppc_after_tlbiel_barrier();
        } else {
                __tlbie(vpn, psize, apsize, ssize);
                fixup_tlbie_vpn(vpn, psize, apsize, ssize);
                asm volatile("eieio; tlbsync; ptesync": : :"memory");
        }
        if (lock_tlbie && !use_local)
                raw_spin_unlock(&native_tlbie_lock);
}

static inline void native_lock_hpte(struct hash_pte *hptep)
{
        unsigned long *word = (unsigned long *)&hptep->v;

        acquire_hpte_lock();
        while (1) {
                if (!test_and_set_bit_lock(HPTE_LOCK_BIT, word))
                        break;
                spin_begin();
                while(test_bit(HPTE_LOCK_BIT, word))
                        spin_cpu_relax();
                spin_end();
        }
}

static inline void native_unlock_hpte(struct hash_pte *hptep)
{
        unsigned long *word = (unsigned long *)&hptep->v;

        release_hpte_lock();
        clear_bit_unlock(HPTE_LOCK_BIT, word);
}

static long native_hpte_insert(unsigned long hpte_group, unsigned long vpn,
                        unsigned long pa, unsigned long rflags,
                        unsigned long vflags, int psize, int apsize, int ssize)
{
        struct hash_pte *hptep = htab_address + hpte_group;
        unsigned long hpte_v, hpte_r;
        unsigned long flags;
        int i;

        local_irq_save(flags);

        if (!(vflags & HPTE_V_BOLTED)) {
                DBG_LOW("    insert(group=%lx, vpn=%016lx, pa=%016lx,"
                        " rflags=%lx, vflags=%lx, psize=%d)\n",
                        hpte_group, vpn, pa, rflags, vflags, psize);
        }

        for (i = 0; i < HPTES_PER_GROUP; i++) {
                if (! (be64_to_cpu(hptep->v) & HPTE_V_VALID)) {
                        /* retry with lock held */
                        native_lock_hpte(hptep);
                        if (! (be64_to_cpu(hptep->v) & HPTE_V_VALID))
                                break;
                        native_unlock_hpte(hptep);
                }

                hptep++;
        }

        if (i == HPTES_PER_GROUP) {
                local_irq_restore(flags);
                return -1;
        }

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

        if (!(vflags & HPTE_V_BOLTED)) {
                DBG_LOW(" i=%x hpte_v=%016lx, hpte_r=%016lx\n",
                        i, hpte_v, hpte_r);
        }

        if (cpu_has_feature(CPU_FTR_ARCH_300)) {
                hpte_r = hpte_old_to_new_r(hpte_v, hpte_r);
                hpte_v = hpte_old_to_new_v(hpte_v);
        }

        hptep->r = cpu_to_be64(hpte_r);
        /* Guarantee the second dword is visible before the valid bit */
        eieio();
        /*
         * Now set the first dword including the valid bit
         * NOTE: this also unlocks the hpte
         */
        release_hpte_lock();
        hptep->v = cpu_to_be64(hpte_v);

        __asm__ __volatile__ ("ptesync" : : : "memory");

        local_irq_restore(flags);

        return i | (!!(vflags & HPTE_V_SECONDARY) << 3);
}

static long native_hpte_remove(unsigned long hpte_group)
{
        unsigned long hpte_v, flags;
        struct hash_pte *hptep;
        int i;
        int slot_offset;

        local_irq_save(flags);

        DBG_LOW("    remove(group=%lx)\n", hpte_group);

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

        for (i = 0; i < HPTES_PER_GROUP; i++) {
                hptep = htab_address + hpte_group + slot_offset;
                hpte_v = be64_to_cpu(hptep->v);

                if ((hpte_v & HPTE_V_VALID) && !(hpte_v & HPTE_V_BOLTED)) {
                        /* retry with lock held */
                        native_lock_hpte(hptep);
                        hpte_v = be64_to_cpu(hptep->v);
                        if ((hpte_v & HPTE_V_VALID)
                            && !(hpte_v & HPTE_V_BOLTED))
                                break;
                        native_unlock_hpte(hptep);
                }

                slot_offset++;
                slot_offset &= 0x7;
        }

        if (i == HPTES_PER_GROUP) {
                i = -1;
                goto out;
        }

        /* Invalidate the hpte. NOTE: this also unlocks it */
        release_hpte_lock();
        hptep->v = 0;
out:
        local_irq_restore(flags);
        return i;
}

static long native_hpte_updatepp(unsigned long slot, unsigned long newpp,
                                 unsigned long vpn, int bpsize,
                                 int apsize, int ssize, unsigned long flags)
{
        struct hash_pte *hptep = htab_address + slot;
        unsigned long hpte_v, want_v;
        int ret = 0, local = 0;
        unsigned long irqflags;

        local_irq_save(irqflags);

        want_v = hpte_encode_avpn(vpn, bpsize, ssize);

        DBG_LOW("    update(vpn=%016lx, avpnv=%016lx, group=%lx, newpp=%lx)",
                vpn, want_v & HPTE_V_AVPN, slot, newpp);

        hpte_v = hpte_get_old_v(hptep);
        /*
         * We need to invalidate the TLB always because hpte_remove doesn't do
         * a tlb invalidate. If a hash bucket gets full, we "evict" a more/less
         * random entry from it. When we do that we don't invalidate the TLB
         * (hpte_remove) because we assume the old translation is still
         * technically "valid".
         */
        if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID)) {
                DBG_LOW(" -> miss\n");
                ret = -1;
        } else {
                native_lock_hpte(hptep);
                /* recheck with locks held */
                hpte_v = hpte_get_old_v(hptep);
                if (unlikely(!HPTE_V_COMPARE(hpte_v, want_v) ||
                             !(hpte_v & HPTE_V_VALID))) {
                        ret = -1;
                } else {
                        DBG_LOW(" -> hit\n");
                        /* Update the HPTE */
                        hptep->r = cpu_to_be64((be64_to_cpu(hptep->r) &
                                                ~(HPTE_R_PPP | HPTE_R_N)) |
                                               (newpp & (HPTE_R_PPP | HPTE_R_N |
                                                         HPTE_R_C)));
                }
                native_unlock_hpte(hptep);
        }

        if (flags & HPTE_LOCAL_UPDATE)
                local = 1;
        /*
         * Ensure it is out of the tlb too if it is not a nohpte fault
         */
        if (!(flags & HPTE_NOHPTE_UPDATE))
                tlbie(vpn, bpsize, apsize, ssize, local);

        local_irq_restore(irqflags);

        return ret;
}

static long __native_hpte_find(unsigned long want_v, unsigned long slot)
{
        struct hash_pte *hptep;
        unsigned long hpte_v;
        unsigned long i;

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

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

        return -1;
}

static long native_hpte_find(unsigned long vpn, int psize, int ssize)
{
        unsigned long hpte_group;
        unsigned long want_v;
        unsigned long hash;
        long slot;

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

        /*
         * We try to keep bolted entries always in primary hash
         * But in some case we can find them in secondary too.
         */
        hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
        slot = __native_hpte_find(want_v, hpte_group);
        if (slot < 0) {
                /* Try in secondary */
                hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
                slot = __native_hpte_find(want_v, hpte_group);
                if (slot < 0)
                        return -1;
        }

        return slot;
}

/*
 * Update the page protection bits. Intended to be used to create
 * guard pages for kernel data structures on pages which are bolted
 * in the HPT. Assumes pages being operated on will not be stolen.
 *
 * No need to lock here because we should be the only user.
 */
static void native_hpte_updateboltedpp(unsigned long newpp, unsigned long ea,
                                       int psize, int ssize)
{
        unsigned long vpn;
        unsigned long vsid;
        long slot;
        struct hash_pte *hptep;
        unsigned long flags;

        local_irq_save(flags);

        vsid = get_kernel_vsid(ea, ssize);
        vpn = hpt_vpn(ea, vsid, ssize);

        slot = native_hpte_find(vpn, psize, ssize);
        if (slot == -1)
                panic("could not find page to bolt\n");
        hptep = htab_address + slot;

        /* Update the HPTE */
        hptep->r = cpu_to_be64((be64_to_cpu(hptep->r) &
                                ~(HPTE_R_PPP | HPTE_R_N)) |
                               (newpp & (HPTE_R_PPP | HPTE_R_N)));
        /*
         * Ensure it is out of the tlb too. Bolted entries base and
         * actual page size will be same.
         */
        tlbie(vpn, psize, psize, ssize, 0);

        local_irq_restore(flags);
}

/*
 * Remove a bolted kernel entry. Memory hotplug uses this.
 *
 * No need to lock here because we should be the only user.
 */
static int native_hpte_removebolted(unsigned long ea, int psize, int ssize)
{
        unsigned long vpn;
        unsigned long vsid;
        long slot;
        struct hash_pte *hptep;
        unsigned long flags;

        local_irq_save(flags);

        vsid = get_kernel_vsid(ea, ssize);
        vpn = hpt_vpn(ea, vsid, ssize);

        slot = native_hpte_find(vpn, psize, ssize);
        if (slot == -1)
                return -ENOENT;

        hptep = htab_address + slot;

        VM_WARN_ON(!(be64_to_cpu(hptep->v) & HPTE_V_BOLTED));

        /* Invalidate the hpte */
        hptep->v = 0;

        /* Invalidate the TLB */
        tlbie(vpn, psize, psize, ssize, 0);

        local_irq_restore(flags);

        return 0;
}


static void native_hpte_invalidate(unsigned long slot, unsigned long vpn,
                                   int bpsize, int apsize, int ssize, int local)
{
        struct hash_pte *hptep = htab_address + slot;
        unsigned long hpte_v;
        unsigned long want_v;
        unsigned long flags;

        local_irq_save(flags);

        DBG_LOW("    invalidate(vpn=%016lx, hash: %lx)\n", vpn, slot);

        want_v = hpte_encode_avpn(vpn, bpsize, ssize);
        hpte_v = hpte_get_old_v(hptep);

        if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID)) {
                native_lock_hpte(hptep);
                /* recheck with locks held */
                hpte_v = hpte_get_old_v(hptep);

                if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID)) {
                        /* Invalidate the hpte. NOTE: this also unlocks it */
                        release_hpte_lock();
                        hptep->v = 0;
                } else
                        native_unlock_hpte(hptep);
        }
        /*
         * We need to invalidate the TLB always because hpte_remove doesn't do
         * a tlb invalidate. If a hash bucket gets full, we "evict" a more/less
         * random entry from it. When we do that we don't invalidate the TLB
         * (hpte_remove) because we assume the old translation is still
         * technically "valid".
         */
        tlbie(vpn, bpsize, apsize, ssize, local);

        local_irq_restore(flags);
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void native_hugepage_invalidate(unsigned long vsid,
                                       unsigned long addr,
                                       unsigned char *hpte_slot_array,
                                       int psize, int ssize, int local)
{
        int i;
        struct hash_pte *hptep;
        int actual_psize = MMU_PAGE_16M;
        unsigned int max_hpte_count, valid;
        unsigned long flags, s_addr = addr;
        unsigned long hpte_v, want_v, shift;
        unsigned long hidx, vpn = 0, hash, slot;

        shift = mmu_psize_defs[psize].shift;
        max_hpte_count = 1U << (PMD_SHIFT - shift);

        local_irq_save(flags);
        for (i = 0; i < max_hpte_count; i++) {
                valid = hpte_valid(hpte_slot_array, i);
                if (!valid)
                        continue;
                hidx =  hpte_hash_index(hpte_slot_array, i);

                /* get the vpn */
                addr = s_addr + (i * (1ul << shift));
                vpn = hpt_vpn(addr, vsid, ssize);
                hash = hpt_hash(vpn, shift, ssize);
                if (hidx & _PTEIDX_SECONDARY)
                        hash = ~hash;

                slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
                slot += hidx & _PTEIDX_GROUP_IX;

                hptep = htab_address + slot;
                want_v = hpte_encode_avpn(vpn, psize, ssize);
                hpte_v = hpte_get_old_v(hptep);

                /* Even if we miss, we need to invalidate the TLB */
                if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID)) {
                        /* recheck with locks held */
                        native_lock_hpte(hptep);
                        hpte_v = hpte_get_old_v(hptep);

                        if (HPTE_V_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID)) {
                                /* Invalidate the hpte. NOTE: this also unlocks it */
                                release_hpte_lock();
                                hptep->v = 0;
                        } else
                                native_unlock_hpte(hptep);
                }
                /*
                 * We need to do tlb invalidate for all the address, tlbie
                 * instruction compares entry_VA in tlb with the VA specified
                 * here
                 */
                tlbie(vpn, psize, actual_psize, ssize, local);
        }
        local_irq_restore(flags);
}
#else
static void native_hugepage_invalidate(unsigned long vsid,
                                       unsigned long addr,
                                       unsigned char *hpte_slot_array,
                                       int psize, int ssize, int local)
{
        WARN(1, "%s called without THP support\n", __func__);
}
#endif

static void hpte_decode(struct hash_pte *hpte, unsigned long slot,
                        int *psize, int *apsize, int *ssize, unsigned long *vpn)
{
        unsigned long avpn, pteg, vpi;
        unsigned long hpte_v = be64_to_cpu(hpte->v);
        unsigned long hpte_r = be64_to_cpu(hpte->r);
        unsigned long vsid, seg_off;
        int size, a_size, shift;
        /* Look at the 8 bit LP value */
        unsigned int lp = (hpte_r >> LP_SHIFT) & ((1 << LP_BITS) - 1);

        if (cpu_has_feature(CPU_FTR_ARCH_300)) {
                hpte_v = hpte_new_to_old_v(hpte_v, hpte_r);
                hpte_r = hpte_new_to_old_r(hpte_r);
        }
        if (!(hpte_v & HPTE_V_LARGE)) {
                size   = MMU_PAGE_4K;
                a_size = MMU_PAGE_4K;
        } else {
                size = hpte_page_sizes[lp] & 0xf;
                a_size = hpte_page_sizes[lp] >> 4;
        }
        /* This works for all page sizes, and for 256M and 1T segments */
        *ssize = hpte_v >> HPTE_V_SSIZE_SHIFT;
        shift = mmu_psize_defs[size].shift;

        avpn = (HPTE_V_AVPN_VAL(hpte_v) & ~mmu_psize_defs[size].avpnm);
        pteg = slot / HPTES_PER_GROUP;
        if (hpte_v & HPTE_V_SECONDARY)
                pteg = ~pteg;

        switch (*ssize) {
        case MMU_SEGSIZE_256M:
                /* We only have 28 - 23 bits of seg_off in avpn */
                seg_off = (avpn & 0x1f) << 23;
                vsid    =  avpn >> 5;
                /* We can find more bits from the pteg value */
                if (shift < 23) {
                        vpi = (vsid ^ pteg) & htab_hash_mask;
                        seg_off |= vpi << shift;
                }
                *vpn = vsid << (SID_SHIFT - VPN_SHIFT) | seg_off >> VPN_SHIFT;
                break;
        case MMU_SEGSIZE_1T:
                /* We only have 40 - 23 bits of seg_off in avpn */
                seg_off = (avpn & 0x1ffff) << 23;
                vsid    = avpn >> 17;
                if (shift < 23) {
                        vpi = (vsid ^ (vsid << 25) ^ pteg) & htab_hash_mask;
                        seg_off |= vpi << shift;
                }
                *vpn = vsid << (SID_SHIFT_1T - VPN_SHIFT) | seg_off >> VPN_SHIFT;
                break;
        default:
                *vpn = size = 0;
        }
        *psize  = size;
        *apsize = a_size;
}

/*
 * clear all mappings on kexec.  All cpus are in real mode (or they will
 * be when they isi), and we are the only one left.  We rely on our kernel
 * mapping being 0xC0's and the hardware ignoring those two real bits.
 *
 * This must be called with interrupts disabled.
 *
 * Taking the native_tlbie_lock is unsafe here due to the possibility of
 * lockdep being on. On pre POWER5 hardware, not taking the lock could
 * cause deadlock. POWER5 and newer not taking the lock is fine. This only
 * gets called during boot before secondary CPUs have come up and during
 * crashdump and all bets are off anyway.
 *
 * TODO: add batching support when enabled.  remember, no dynamic memory here,
 * although there is the control page available...
 */
static notrace void native_hpte_clear(void)
{
        unsigned long vpn = 0;
        unsigned long slot, slots;
        struct hash_pte *hptep = htab_address;
        unsigned long hpte_v;
        unsigned long pteg_count;
        int psize, apsize, ssize;

        pteg_count = htab_hash_mask + 1;

        slots = pteg_count * HPTES_PER_GROUP;

        for (slot = 0; slot < slots; slot++, hptep++) {
                /*
                 * we could lock the pte here, but we are the only cpu
                 * running,  right?  and for crash dump, we probably
                 * don't want to wait for a maybe bad cpu.
                 */
                hpte_v = be64_to_cpu(hptep->v);

                /*
                 * Call __tlbie() here rather than tlbie() since we can't take the
                 * native_tlbie_lock.
                 */
                if (hpte_v & HPTE_V_VALID) {
                        hpte_decode(hptep, slot, &psize, &apsize, &ssize, &vpn);
                        hptep->v = 0;
                        ___tlbie(vpn, psize, apsize, ssize);
                }
        }

        asm volatile("eieio; tlbsync; ptesync":::"memory");
}

/*
 * Batched hash table flush, we batch the tlbie's to avoid taking/releasing
 * the lock all the time
 */
static void native_flush_hash_range(unsigned long number, int local)
{
        unsigned long vpn = 0;
        unsigned long hash, index, hidx, shift, slot;
        struct hash_pte *hptep;
        unsigned long hpte_v;
        unsigned long want_v;
        unsigned long flags;
        real_pte_t pte;
        struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
        unsigned long psize = batch->psize;
        int ssize = batch->ssize;
        int i;

        local_irq_save(flags);

        for (i = 0; i < number; i++) {
                vpn = batch->vpn[i];
                pte = batch->pte[i];

                pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
                        hash = hpt_hash(vpn, 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;
                        hptep = htab_address + slot;
                        want_v = hpte_encode_avpn(vpn, psize, ssize);
                        hpte_v = hpte_get_old_v(hptep);

                        if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID))
                                continue;
                        /* lock and try again */
                        native_lock_hpte(hptep);
                        hpte_v = hpte_get_old_v(hptep);

                        if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID))
                                native_unlock_hpte(hptep);
                        else {
                                release_hpte_lock();
                                hptep->v = 0;
                        }

                } pte_iterate_hashed_end();
        }

        if (mmu_has_feature(MMU_FTR_TLBIEL) &&
            mmu_psize_defs[psize].tlbiel && local) {
                asm volatile("ptesync":::"memory");
                for (i = 0; i < number; i++) {
                        vpn = batch->vpn[i];
                        pte = batch->pte[i];

                        pte_iterate_hashed_subpages(pte, psize,
                                                    vpn, index, shift) {
                                __tlbiel(vpn, psize, psize, ssize);
                        } pte_iterate_hashed_end();
                }
                ppc_after_tlbiel_barrier();
        } else {
                int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);

                if (lock_tlbie)
                        raw_spin_lock(&native_tlbie_lock);

                asm volatile("ptesync":::"memory");
                for (i = 0; i < number; i++) {
                        vpn = batch->vpn[i];
                        pte = batch->pte[i];

                        pte_iterate_hashed_subpages(pte, psize,
                                                    vpn, index, shift) {
                                __tlbie(vpn, psize, psize, ssize);
                        } pte_iterate_hashed_end();
                }
                /*
                 * Just do one more with the last used values.
                 */
                fixup_tlbie_vpn(vpn, psize, psize, ssize);
                asm volatile("eieio; tlbsync; ptesync":::"memory");

                if (lock_tlbie)
                        raw_spin_unlock(&native_tlbie_lock);
        }

        local_irq_restore(flags);
}

void __init hpte_init_native(void)
{
        mmu_hash_ops.hpte_invalidate    = native_hpte_invalidate;
        mmu_hash_ops.hpte_updatepp      = native_hpte_updatepp;
        mmu_hash_ops.hpte_updateboltedpp = native_hpte_updateboltedpp;
        mmu_hash_ops.hpte_removebolted = native_hpte_removebolted;
        mmu_hash_ops.hpte_insert        = native_hpte_insert;
        mmu_hash_ops.hpte_remove        = native_hpte_remove;
        mmu_hash_ops.hpte_clear_all     = native_hpte_clear;
        mmu_hash_ops.flush_hash_range = native_flush_hash_range;
        mmu_hash_ops.hugepage_invalidate   = native_hugepage_invalidate;
}