forked from Minki/linux
47f78a4920
native_hpte_clear has a spinlock recursion problem with the native_tlbie_lock being called twice, once in native_hpte_clear() and once within tlbie(). Fix the problem by changing the call to tlbie() in native_hpte_clear() to __tlbie(). It still supports only 4k pages for now. Signed-off-by: R Sharada <sharada@in.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
535 lines
12 KiB
C
535 lines
12 KiB
C
/*
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* native hashtable management.
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*
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* SMP scalability work:
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* Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#undef DEBUG_LOW
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#include <linux/spinlock.h>
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#include <linux/bitops.h>
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#include <linux/threads.h>
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#include <linux/smp.h>
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#include <asm/abs_addr.h>
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#include <asm/machdep.h>
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#include <asm/mmu.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/tlb.h>
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#include <asm/cputable.h>
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#include <asm/udbg.h>
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#ifdef DEBUG_LOW
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#define DBG_LOW(fmt...) udbg_printf(fmt)
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#else
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#define DBG_LOW(fmt...)
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#endif
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#define HPTE_LOCK_BIT 3
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static DEFINE_SPINLOCK(native_tlbie_lock);
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static inline void __tlbie(unsigned long va, unsigned int psize)
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{
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unsigned int penc;
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/* clear top 16 bits, non SLS segment */
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va &= ~(0xffffULL << 48);
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switch (psize) {
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case MMU_PAGE_4K:
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va &= ~0xffful;
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asm volatile("tlbie %0,0" : : "r" (va) : "memory");
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break;
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default:
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penc = mmu_psize_defs[psize].penc;
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va &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
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va |= (0x7f >> (8 - penc)) << 12;
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asm volatile("tlbie %0,1" : : "r" (va) : "memory");
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break;
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}
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}
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static inline void __tlbiel(unsigned long va, unsigned int psize)
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{
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unsigned int penc;
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/* clear top 16 bits, non SLS segment */
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va &= ~(0xffffULL << 48);
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switch (psize) {
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case MMU_PAGE_4K:
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va &= ~0xffful;
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asm volatile(".long 0x7c000224 | (%0 << 11) | (0 << 21)"
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: : "r"(va) : "memory");
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break;
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default:
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penc = mmu_psize_defs[psize].penc;
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va &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
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va |= (0x7f >> (8 - penc)) << 12;
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asm volatile(".long 0x7c000224 | (%0 << 11) | (1 << 21)"
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: : "r"(va) : "memory");
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break;
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}
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}
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static inline void tlbie(unsigned long va, int psize, int local)
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{
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unsigned int use_local = local && cpu_has_feature(CPU_FTR_TLBIEL);
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int lock_tlbie = !cpu_has_feature(CPU_FTR_LOCKLESS_TLBIE);
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if (use_local)
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use_local = mmu_psize_defs[psize].tlbiel;
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if (lock_tlbie && !use_local)
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spin_lock(&native_tlbie_lock);
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asm volatile("ptesync": : :"memory");
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if (use_local) {
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__tlbiel(va, psize);
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asm volatile("ptesync": : :"memory");
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} else {
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__tlbie(va, psize);
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asm volatile("eieio; tlbsync; ptesync": : :"memory");
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}
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if (lock_tlbie && !use_local)
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spin_unlock(&native_tlbie_lock);
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}
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static inline void native_lock_hpte(hpte_t *hptep)
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{
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unsigned long *word = &hptep->v;
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while (1) {
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if (!test_and_set_bit(HPTE_LOCK_BIT, word))
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break;
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while(test_bit(HPTE_LOCK_BIT, word))
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cpu_relax();
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}
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}
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static inline void native_unlock_hpte(hpte_t *hptep)
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{
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unsigned long *word = &hptep->v;
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asm volatile("lwsync":::"memory");
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clear_bit(HPTE_LOCK_BIT, word);
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}
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long native_hpte_insert(unsigned long hpte_group, unsigned long va,
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unsigned long pa, unsigned long rflags,
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unsigned long vflags, int psize)
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{
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hpte_t *hptep = htab_address + hpte_group;
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unsigned long hpte_v, hpte_r;
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int i;
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if (!(vflags & HPTE_V_BOLTED)) {
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DBG_LOW(" insert(group=%lx, va=%016lx, pa=%016lx,"
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" rflags=%lx, vflags=%lx, psize=%d)\n",
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hpte_group, va, pa, rflags, vflags, psize);
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}
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for (i = 0; i < HPTES_PER_GROUP; i++) {
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if (! (hptep->v & HPTE_V_VALID)) {
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/* retry with lock held */
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native_lock_hpte(hptep);
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if (! (hptep->v & HPTE_V_VALID))
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break;
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native_unlock_hpte(hptep);
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}
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hptep++;
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}
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if (i == HPTES_PER_GROUP)
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return -1;
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hpte_v = hpte_encode_v(va, psize) | vflags | HPTE_V_VALID;
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hpte_r = hpte_encode_r(pa, psize) | rflags;
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if (!(vflags & HPTE_V_BOLTED)) {
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DBG_LOW(" i=%x hpte_v=%016lx, hpte_r=%016lx\n",
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i, hpte_v, hpte_r);
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}
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hptep->r = hpte_r;
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/* Guarantee the second dword is visible before the valid bit */
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__asm__ __volatile__ ("eieio" : : : "memory");
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/*
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* Now set the first dword including the valid bit
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* NOTE: this also unlocks the hpte
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*/
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hptep->v = hpte_v;
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__asm__ __volatile__ ("ptesync" : : : "memory");
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return i | (!!(vflags & HPTE_V_SECONDARY) << 3);
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}
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static long native_hpte_remove(unsigned long hpte_group)
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{
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hpte_t *hptep;
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int i;
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int slot_offset;
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unsigned long hpte_v;
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DBG_LOW(" remove(group=%lx)\n", hpte_group);
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/* pick a random entry to start at */
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slot_offset = mftb() & 0x7;
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for (i = 0; i < HPTES_PER_GROUP; i++) {
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hptep = htab_address + hpte_group + slot_offset;
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hpte_v = hptep->v;
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if ((hpte_v & HPTE_V_VALID) && !(hpte_v & HPTE_V_BOLTED)) {
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/* retry with lock held */
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native_lock_hpte(hptep);
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hpte_v = hptep->v;
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if ((hpte_v & HPTE_V_VALID)
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&& !(hpte_v & HPTE_V_BOLTED))
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break;
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native_unlock_hpte(hptep);
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}
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slot_offset++;
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slot_offset &= 0x7;
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}
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if (i == HPTES_PER_GROUP)
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return -1;
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/* Invalidate the hpte. NOTE: this also unlocks it */
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hptep->v = 0;
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return i;
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}
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static long native_hpte_updatepp(unsigned long slot, unsigned long newpp,
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unsigned long va, int psize, int local)
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{
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hpte_t *hptep = htab_address + slot;
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unsigned long hpte_v, want_v;
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int ret = 0;
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want_v = hpte_encode_v(va, psize);
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DBG_LOW(" update(va=%016lx, avpnv=%016lx, hash=%016lx, newpp=%x)",
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va, want_v & HPTE_V_AVPN, slot, newpp);
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native_lock_hpte(hptep);
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hpte_v = hptep->v;
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/* Even if we miss, we need to invalidate the TLB */
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if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID)) {
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DBG_LOW(" -> miss\n");
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native_unlock_hpte(hptep);
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ret = -1;
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} else {
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DBG_LOW(" -> hit\n");
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/* Update the HPTE */
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hptep->r = (hptep->r & ~(HPTE_R_PP | HPTE_R_N)) |
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(newpp & (HPTE_R_PP | HPTE_R_N));
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native_unlock_hpte(hptep);
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}
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/* Ensure it is out of the tlb too. */
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tlbie(va, psize, local);
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return ret;
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}
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static long native_hpte_find(unsigned long va, int psize)
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{
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hpte_t *hptep;
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unsigned long hash;
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unsigned long i, j;
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long slot;
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unsigned long want_v, hpte_v;
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hash = hpt_hash(va, mmu_psize_defs[psize].shift);
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want_v = hpte_encode_v(va, psize);
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for (j = 0; j < 2; j++) {
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slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
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for (i = 0; i < HPTES_PER_GROUP; i++) {
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hptep = htab_address + slot;
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hpte_v = hptep->v;
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if (HPTE_V_COMPARE(hpte_v, want_v)
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&& (hpte_v & HPTE_V_VALID)
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&& ( !!(hpte_v & HPTE_V_SECONDARY) == j)) {
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/* HPTE matches */
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if (j)
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slot = -slot;
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return slot;
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}
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++slot;
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}
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hash = ~hash;
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}
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return -1;
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}
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/*
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* Update the page protection bits. Intended to be used to create
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* guard pages for kernel data structures on pages which are bolted
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* in the HPT. Assumes pages being operated on will not be stolen.
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*
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* No need to lock here because we should be the only user.
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*/
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static void native_hpte_updateboltedpp(unsigned long newpp, unsigned long ea,
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int psize)
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{
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unsigned long vsid, va;
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long slot;
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hpte_t *hptep;
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vsid = get_kernel_vsid(ea);
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va = (vsid << 28) | (ea & 0x0fffffff);
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slot = native_hpte_find(va, psize);
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if (slot == -1)
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panic("could not find page to bolt\n");
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hptep = htab_address + slot;
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/* Update the HPTE */
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hptep->r = (hptep->r & ~(HPTE_R_PP | HPTE_R_N)) |
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(newpp & (HPTE_R_PP | HPTE_R_N));
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/* Ensure it is out of the tlb too. */
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tlbie(va, psize, 0);
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}
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static void native_hpte_invalidate(unsigned long slot, unsigned long va,
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int psize, int local)
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{
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hpte_t *hptep = htab_address + slot;
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unsigned long hpte_v;
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unsigned long want_v;
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unsigned long flags;
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local_irq_save(flags);
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DBG_LOW(" invalidate(va=%016lx, hash: %x)\n", va, slot);
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want_v = hpte_encode_v(va, psize);
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native_lock_hpte(hptep);
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hpte_v = hptep->v;
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/* Even if we miss, we need to invalidate the TLB */
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if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID))
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native_unlock_hpte(hptep);
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else
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/* Invalidate the hpte. NOTE: this also unlocks it */
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hptep->v = 0;
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/* Invalidate the TLB */
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tlbie(va, psize, local);
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local_irq_restore(flags);
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}
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/*
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* XXX This need fixing based on page size. It's only used by
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* native_hpte_clear() for now which needs fixing too so they
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* make a good pair...
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*/
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static unsigned long slot2va(unsigned long hpte_v, unsigned long slot)
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{
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unsigned long avpn = HPTE_V_AVPN_VAL(hpte_v);
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unsigned long va;
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va = avpn << 23;
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if (! (hpte_v & HPTE_V_LARGE)) {
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unsigned long vpi, pteg;
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pteg = slot / HPTES_PER_GROUP;
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if (hpte_v & HPTE_V_SECONDARY)
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pteg = ~pteg;
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vpi = ((va >> 28) ^ pteg) & htab_hash_mask;
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va |= vpi << PAGE_SHIFT;
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}
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return va;
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}
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/*
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* clear all mappings on kexec. All cpus are in real mode (or they will
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* be when they isi), and we are the only one left. We rely on our kernel
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* mapping being 0xC0's and the hardware ignoring those two real bits.
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*
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* TODO: add batching support when enabled. remember, no dynamic memory here,
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* athough there is the control page available...
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*
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* XXX FIXME: 4k only for now !
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*/
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static void native_hpte_clear(void)
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{
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unsigned long slot, slots, flags;
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hpte_t *hptep = htab_address;
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unsigned long hpte_v;
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unsigned long pteg_count;
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pteg_count = htab_hash_mask + 1;
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local_irq_save(flags);
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/* we take the tlbie lock and hold it. Some hardware will
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* deadlock if we try to tlbie from two processors at once.
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*/
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spin_lock(&native_tlbie_lock);
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slots = pteg_count * HPTES_PER_GROUP;
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for (slot = 0; slot < slots; slot++, hptep++) {
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/*
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* we could lock the pte here, but we are the only cpu
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* running, right? and for crash dump, we probably
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* don't want to wait for a maybe bad cpu.
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*/
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hpte_v = hptep->v;
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/*
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* Call __tlbie() here rather than tlbie() since we
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* already hold the native_tlbie_lock.
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*/
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if (hpte_v & HPTE_V_VALID) {
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hptep->v = 0;
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__tlbie(slot2va(hpte_v, slot), MMU_PAGE_4K);
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}
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}
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asm volatile("eieio; tlbsync; ptesync":::"memory");
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spin_unlock(&native_tlbie_lock);
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local_irq_restore(flags);
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}
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/*
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* Batched hash table flush, we batch the tlbie's to avoid taking/releasing
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* the lock all the time
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*/
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static void native_flush_hash_range(unsigned long number, int local)
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{
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unsigned long va, hash, index, hidx, shift, slot;
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hpte_t *hptep;
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unsigned long hpte_v;
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unsigned long want_v;
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unsigned long flags;
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real_pte_t pte;
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struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
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unsigned long psize = batch->psize;
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int i;
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local_irq_save(flags);
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for (i = 0; i < number; i++) {
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va = batch->vaddr[i];
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pte = batch->pte[i];
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pte_iterate_hashed_subpages(pte, psize, va, index, shift) {
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hash = hpt_hash(va, shift);
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hidx = __rpte_to_hidx(pte, index);
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if (hidx & _PTEIDX_SECONDARY)
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hash = ~hash;
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slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
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slot += hidx & _PTEIDX_GROUP_IX;
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hptep = htab_address + slot;
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want_v = hpte_encode_v(va, psize);
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native_lock_hpte(hptep);
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hpte_v = hptep->v;
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if (!HPTE_V_COMPARE(hpte_v, want_v) ||
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!(hpte_v & HPTE_V_VALID))
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native_unlock_hpte(hptep);
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else
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hptep->v = 0;
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} pte_iterate_hashed_end();
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}
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if (cpu_has_feature(CPU_FTR_TLBIEL) &&
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mmu_psize_defs[psize].tlbiel && local) {
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asm volatile("ptesync":::"memory");
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for (i = 0; i < number; i++) {
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va = batch->vaddr[i];
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pte = batch->pte[i];
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pte_iterate_hashed_subpages(pte, psize, va, index,
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shift) {
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__tlbiel(va, psize);
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} pte_iterate_hashed_end();
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}
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asm volatile("ptesync":::"memory");
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} else {
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int lock_tlbie = !cpu_has_feature(CPU_FTR_LOCKLESS_TLBIE);
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if (lock_tlbie)
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spin_lock(&native_tlbie_lock);
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asm volatile("ptesync":::"memory");
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for (i = 0; i < number; i++) {
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va = batch->vaddr[i];
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pte = batch->pte[i];
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pte_iterate_hashed_subpages(pte, psize, va, index,
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shift) {
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__tlbie(va, psize);
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} pte_iterate_hashed_end();
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}
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asm volatile("eieio; tlbsync; ptesync":::"memory");
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if (lock_tlbie)
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spin_unlock(&native_tlbie_lock);
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}
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local_irq_restore(flags);
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}
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#ifdef CONFIG_PPC_PSERIES
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/* Disable TLB batching on nighthawk */
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static inline int tlb_batching_enabled(void)
|
|
{
|
|
struct device_node *root = of_find_node_by_path("/");
|
|
int enabled = 1;
|
|
|
|
if (root) {
|
|
const char *model = get_property(root, "model", NULL);
|
|
if (model && !strcmp(model, "IBM,9076-N81"))
|
|
enabled = 0;
|
|
of_node_put(root);
|
|
}
|
|
|
|
return enabled;
|
|
}
|
|
#else
|
|
static inline int tlb_batching_enabled(void)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
void hpte_init_native(void)
|
|
{
|
|
ppc_md.hpte_invalidate = native_hpte_invalidate;
|
|
ppc_md.hpte_updatepp = native_hpte_updatepp;
|
|
ppc_md.hpte_updateboltedpp = native_hpte_updateboltedpp;
|
|
ppc_md.hpte_insert = native_hpte_insert;
|
|
ppc_md.hpte_remove = native_hpte_remove;
|
|
ppc_md.hpte_clear_all = native_hpte_clear;
|
|
if (tlb_batching_enabled())
|
|
ppc_md.flush_hash_range = native_flush_hash_range;
|
|
htab_finish_init();
|
|
}
|