diff options
Diffstat (limited to 'arch/powerpc/mm/hash_native_64.c')
-rw-r--r-- | arch/powerpc/mm/hash_native_64.c | 446 |
1 files changed, 446 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c new file mode 100644 index 000000000000..174d14576c28 --- /dev/null +++ b/arch/powerpc/mm/hash_native_64.c @@ -0,0 +1,446 @@ +/* + * native hashtable management. + * + * SMP scalability work: + * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM + * + * 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. + */ +#include <linux/spinlock.h> +#include <linux/bitops.h> +#include <linux/threads.h> +#include <linux/smp.h> + +#include <asm/abs_addr.h> +#include <asm/machdep.h> +#include <asm/mmu.h> +#include <asm/mmu_context.h> +#include <asm/pgtable.h> +#include <asm/tlbflush.h> +#include <asm/tlb.h> +#include <asm/cputable.h> + +#define HPTE_LOCK_BIT 3 + +static DEFINE_SPINLOCK(native_tlbie_lock); + +static inline void native_lock_hpte(hpte_t *hptep) +{ + unsigned long *word = &hptep->v; + + while (1) { + if (!test_and_set_bit(HPTE_LOCK_BIT, word)) + break; + while(test_bit(HPTE_LOCK_BIT, word)) + cpu_relax(); + } +} + +static inline void native_unlock_hpte(hpte_t *hptep) +{ + unsigned long *word = &hptep->v; + + asm volatile("lwsync":::"memory"); + clear_bit(HPTE_LOCK_BIT, word); +} + +long native_hpte_insert(unsigned long hpte_group, unsigned long va, + unsigned long prpn, unsigned long vflags, + unsigned long rflags) +{ + hpte_t *hptep = htab_address + hpte_group; + unsigned long hpte_v, hpte_r; + int i; + + for (i = 0; i < HPTES_PER_GROUP; i++) { + if (! (hptep->v & HPTE_V_VALID)) { + /* retry with lock held */ + native_lock_hpte(hptep); + if (! (hptep->v & HPTE_V_VALID)) + break; + native_unlock_hpte(hptep); + } + + hptep++; + } + + if (i == HPTES_PER_GROUP) + return -1; + + hpte_v = (va >> 23) << HPTE_V_AVPN_SHIFT | vflags | HPTE_V_VALID; + if (vflags & HPTE_V_LARGE) + va &= ~(1UL << HPTE_V_AVPN_SHIFT); + hpte_r = (prpn << HPTE_R_RPN_SHIFT) | rflags; + + hptep->r = hpte_r; + /* Guarantee the second dword is visible before the valid bit */ + __asm__ __volatile__ ("eieio" : : : "memory"); + /* + * Now set the first dword including the valid bit + * NOTE: this also unlocks the hpte + */ + hptep->v = hpte_v; + + __asm__ __volatile__ ("ptesync" : : : "memory"); + + return i | (!!(vflags & HPTE_V_SECONDARY) << 3); +} + +static long native_hpte_remove(unsigned long hpte_group) +{ + hpte_t *hptep; + int i; + int slot_offset; + unsigned long hpte_v; + + /* 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 = hptep->v; + + if ((hpte_v & HPTE_V_VALID) && !(hpte_v & HPTE_V_BOLTED)) { + /* retry with lock held */ + native_lock_hpte(hptep); + hpte_v = 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) + return -1; + + /* Invalidate the hpte. NOTE: this also unlocks it */ + hptep->v = 0; + + return i; +} + +static inline void set_pp_bit(unsigned long pp, hpte_t *addr) +{ + unsigned long old; + unsigned long *p = &addr->r; + + __asm__ __volatile__( + "1: ldarx %0,0,%3\n\ + rldimi %0,%2,0,61\n\ + stdcx. %0,0,%3\n\ + bne 1b" + : "=&r" (old), "=m" (*p) + : "r" (pp), "r" (p), "m" (*p) + : "cc"); +} + +/* + * Only works on small pages. Yes its ugly to have to check each slot in + * the group but we only use this during bootup. + */ +static long native_hpte_find(unsigned long vpn) +{ + hpte_t *hptep; + unsigned long hash; + unsigned long i, j; + long slot; + unsigned long hpte_v; + + hash = hpt_hash(vpn, 0); + + for (j = 0; j < 2; j++) { + slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; + for (i = 0; i < HPTES_PER_GROUP; i++) { + hptep = htab_address + slot; + hpte_v = hptep->v; + + if ((HPTE_V_AVPN_VAL(hpte_v) == (vpn >> 11)) + && (hpte_v & HPTE_V_VALID) + && ( !!(hpte_v & HPTE_V_SECONDARY) == j)) { + /* HPTE matches */ + if (j) + slot = -slot; + return slot; + } + ++slot; + } + hash = ~hash; + } + + return -1; +} + +static long native_hpte_updatepp(unsigned long slot, unsigned long newpp, + unsigned long va, int large, int local) +{ + hpte_t *hptep = htab_address + slot; + unsigned long hpte_v; + unsigned long avpn = va >> 23; + int ret = 0; + + if (large) + avpn &= ~1; + + native_lock_hpte(hptep); + + hpte_v = hptep->v; + + /* Even if we miss, we need to invalidate the TLB */ + if ((HPTE_V_AVPN_VAL(hpte_v) != avpn) + || !(hpte_v & HPTE_V_VALID)) { + native_unlock_hpte(hptep); + ret = -1; + } else { + set_pp_bit(newpp, hptep); + native_unlock_hpte(hptep); + } + + /* Ensure it is out of the tlb too */ + if (cpu_has_feature(CPU_FTR_TLBIEL) && !large && local) { + tlbiel(va); + } else { + int lock_tlbie = !cpu_has_feature(CPU_FTR_LOCKLESS_TLBIE); + + if (lock_tlbie) + spin_lock(&native_tlbie_lock); + tlbie(va, large); + if (lock_tlbie) + spin_unlock(&native_tlbie_lock); + } + + return ret; +} + +/* + * 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. + * Does not work on large pages. + * + * No need to lock here because we should be the only user. + */ +static void native_hpte_updateboltedpp(unsigned long newpp, unsigned long ea) +{ + unsigned long vsid, va, vpn, flags = 0; + long slot; + hpte_t *hptep; + int lock_tlbie = !cpu_has_feature(CPU_FTR_LOCKLESS_TLBIE); + + vsid = get_kernel_vsid(ea); + va = (vsid << 28) | (ea & 0x0fffffff); + vpn = va >> PAGE_SHIFT; + + slot = native_hpte_find(vpn); + if (slot == -1) + panic("could not find page to bolt\n"); + hptep = htab_address + slot; + + set_pp_bit(newpp, hptep); + + /* Ensure it is out of the tlb too */ + if (lock_tlbie) + spin_lock_irqsave(&native_tlbie_lock, flags); + tlbie(va, 0); + if (lock_tlbie) + spin_unlock_irqrestore(&native_tlbie_lock, flags); +} + +static void native_hpte_invalidate(unsigned long slot, unsigned long va, + int large, int local) +{ + hpte_t *hptep = htab_address + slot; + unsigned long hpte_v; + unsigned long avpn = va >> 23; + unsigned long flags; + int lock_tlbie = !cpu_has_feature(CPU_FTR_LOCKLESS_TLBIE); + + if (large) + avpn &= ~1; + + local_irq_save(flags); + native_lock_hpte(hptep); + + hpte_v = hptep->v; + + /* Even if we miss, we need to invalidate the TLB */ + if ((HPTE_V_AVPN_VAL(hpte_v) != avpn) + || !(hpte_v & HPTE_V_VALID)) { + native_unlock_hpte(hptep); + } else { + /* Invalidate the hpte. NOTE: this also unlocks it */ + hptep->v = 0; + } + + /* Invalidate the tlb */ + if (cpu_has_feature(CPU_FTR_TLBIEL) && !large && local) { + tlbiel(va); + } else { + if (lock_tlbie) + spin_lock(&native_tlbie_lock); + tlbie(va, large); + if (lock_tlbie) + spin_unlock(&native_tlbie_lock); + } + local_irq_restore(flags); +} + +/* + * 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. + * + * TODO: add batching support when enabled. remember, no dynamic memory here, + * athough there is the control page available... + */ +static void native_hpte_clear(void) +{ + unsigned long slot, slots, flags; + hpte_t *hptep = htab_address; + unsigned long hpte_v; + unsigned long pteg_count; + + pteg_count = htab_hash_mask + 1; + + local_irq_save(flags); + + /* we take the tlbie lock and hold it. Some hardware will + * deadlock if we try to tlbie from two processors at once. + */ + spin_lock(&native_tlbie_lock); + + 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 = hptep->v; + + if (hpte_v & HPTE_V_VALID) { + hptep->v = 0; + tlbie(slot2va(hpte_v, slot), hpte_v & HPTE_V_LARGE); + } + } + + spin_unlock(&native_tlbie_lock); + local_irq_restore(flags); +} + +static void native_flush_hash_range(unsigned long number, int local) +{ + unsigned long va, vpn, hash, secondary, slot, flags, avpn; + int i, j; + hpte_t *hptep; + unsigned long hpte_v; + struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch); + unsigned long large = batch->large; + + local_irq_save(flags); + + j = 0; + for (i = 0; i < number; i++) { + va = batch->vaddr[j]; + if (large) + vpn = va >> HPAGE_SHIFT; + else + vpn = va >> PAGE_SHIFT; + hash = hpt_hash(vpn, large); + secondary = (pte_val(batch->pte[i]) & _PAGE_SECONDARY) >> 15; + if (secondary) + hash = ~hash; + slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; + slot += (pte_val(batch->pte[i]) & _PAGE_GROUP_IX) >> 12; + + hptep = htab_address + slot; + + avpn = va >> 23; + if (large) + avpn &= ~0x1UL; + + native_lock_hpte(hptep); + + hpte_v = hptep->v; + + /* Even if we miss, we need to invalidate the TLB */ + if ((HPTE_V_AVPN_VAL(hpte_v) != avpn) + || !(hpte_v & HPTE_V_VALID)) { + native_unlock_hpte(hptep); + } else { + /* Invalidate the hpte. NOTE: this also unlocks it */ + hptep->v = 0; + } + + j++; + } + + if (cpu_has_feature(CPU_FTR_TLBIEL) && !large && local) { + asm volatile("ptesync":::"memory"); + + for (i = 0; i < j; i++) + __tlbiel(batch->vaddr[i]); + + asm volatile("ptesync":::"memory"); + } else { + int lock_tlbie = !cpu_has_feature(CPU_FTR_LOCKLESS_TLBIE); + + if (lock_tlbie) + spin_lock(&native_tlbie_lock); + + asm volatile("ptesync":::"memory"); + + for (i = 0; i < j; i++) + __tlbie(batch->vaddr[i], large); + + asm volatile("eieio; tlbsync; ptesync":::"memory"); + + if (lock_tlbie) + spin_unlock(&native_tlbie_lock); + } + + local_irq_restore(flags); +} + +#ifdef CONFIG_PPC_PSERIES +/* Disable TLB batching on nighthawk */ +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(); +} |