/* * 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. */ #undef DEBUG_LOW #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> #include <asm/udbg.h> #include <asm/kexec.h> #ifdef DEBUG_LOW #define DBG_LOW(fmt...) udbg_printf(fmt) #else #define DBG_LOW(fmt...) #endif #define HPTE_LOCK_BIT 3 static DEFINE_SPINLOCK(native_tlbie_lock); static inline void __tlbie(unsigned long va, int psize, int ssize) { unsigned int penc; /* clear top 16 bits, non SLS segment */ va &= ~(0xffffULL << 48); switch (psize) { case MMU_PAGE_4K: va &= ~0xffful; va |= ssize << 8; asm volatile("tlbie %0,0" : : "r" (va) : "memory"); break; default: penc = mmu_psize_defs[psize].penc; va &= ~((1ul << mmu_psize_defs[psize].shift) - 1); va |= penc << 12; va |= ssize << 8; asm volatile("tlbie %0,1" : : "r" (va) : "memory"); break; } } static inline void __tlbiel(unsigned long va, int psize, int ssize) { unsigned int penc; /* clear top 16 bits, non SLS segment */ va &= ~(0xffffULL << 48); switch (psize) { case MMU_PAGE_4K: va &= ~0xffful; va |= ssize << 8; asm volatile(".long 0x7c000224 | (%0 << 11) | (0 << 21)" : : "r"(va) : "memory"); break; default: penc = mmu_psize_defs[psize].penc; va &= ~((1ul << mmu_psize_defs[psize].shift) - 1); va |= penc << 12; va |= ssize << 8; asm volatile(".long 0x7c000224 | (%0 << 11) | (1 << 21)" : : "r"(va) : "memory"); break; } } static inline void tlbie(unsigned long va, int psize, int ssize, int local) { unsigned int use_local = local && cpu_has_feature(CPU_FTR_TLBIEL); int lock_tlbie = !cpu_has_feature(CPU_FTR_LOCKLESS_TLBIE); if (use_local) use_local = mmu_psize_defs[psize].tlbiel; if (lock_tlbie && !use_local) spin_lock(&native_tlbie_lock); asm volatile("ptesync": : :"memory"); if (use_local) { __tlbiel(va, psize, ssize); asm volatile("ptesync": : :"memory"); } else { __tlbie(va, psize, ssize); asm volatile("eieio; tlbsync; ptesync": : :"memory"); } if (lock_tlbie && !use_local) spin_unlock(&native_tlbie_lock); } static inline void native_lock_hpte(struct hash_pte *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(struct hash_pte *hptep) { unsigned long *word = &hptep->v; asm volatile("lwsync":::"memory"); clear_bit(HPTE_LOCK_BIT, word); } static long native_hpte_insert(unsigned long hpte_group, unsigned long va, unsigned long pa, unsigned long rflags, unsigned long vflags, int psize, int ssize) { struct hash_pte *hptep = htab_address + hpte_group; unsigned long hpte_v, hpte_r; int i; if (!(vflags & HPTE_V_BOLTED)) { DBG_LOW(" insert(group=%lx, va=%016lx, pa=%016lx," " rflags=%lx, vflags=%lx, psize=%d)\n", hpte_group, va, pa, rflags, vflags, psize); } 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 = hpte_encode_v(va, psize, ssize) | vflags | HPTE_V_VALID; hpte_r = hpte_encode_r(pa, psize) | rflags; if (!(vflags & HPTE_V_BOLTED)) { DBG_LOW(" i=%x hpte_v=%016lx, hpte_r=%016lx\n", i, hpte_v, hpte_r); } hptep->r = 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 */ hptep->v = hpte_v; __asm__ __volatile__ ("ptesync" : : : "memory"); return i | (!!(vflags & HPTE_V_SECONDARY) << 3); } static long native_hpte_remove(unsigned long hpte_group) { struct hash_pte *hptep; int i; int slot_offset; unsigned long hpte_v; 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 = 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 long native_hpte_updatepp(unsigned long slot, unsigned long newpp, unsigned long va, int psize, int ssize, int local) { struct hash_pte *hptep = htab_address + slot; unsigned long hpte_v, want_v; int ret = 0; want_v = hpte_encode_v(va, psize, ssize); DBG_LOW(" update(va=%016lx, avpnv=%016lx, hash=%016lx, newpp=%x)", va, want_v & HPTE_V_AVPN, slot, newpp); native_lock_hpte(hptep); hpte_v = hptep->v; /* Even if we miss, we need to invalidate the TLB */ if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID)) { DBG_LOW(" -> miss\n"); ret = -1; } else { DBG_LOW(" -> hit\n"); /* Update the HPTE */ hptep->r = (hptep->r & ~(HPTE_R_PP | HPTE_R_N)) | (newpp & (HPTE_R_PP | HPTE_R_N | HPTE_R_C)); } native_unlock_hpte(hptep); /* Ensure it is out of the tlb too. */ tlbie(va, psize, ssize, local); return ret; } static long native_hpte_find(unsigned long va, int psize, int ssize) { struct hash_pte *hptep; 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_v(va, psize, ssize); /* Bolted mappings are only ever in the primary group */ 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_COMPARE(hpte_v, want_v) && (hpte_v & HPTE_V_VALID)) /* HPTE matches */ return slot; ++slot; } return -1; } /* * 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 vsid, va; long slot; struct hash_pte *hptep; vsid = get_kernel_vsid(ea, ssize); va = hpt_va(ea, vsid, ssize); slot = native_hpte_find(va, psize, ssize); if (slot == -1) panic("could not find page to bolt\n"); hptep = htab_address + slot; /* Update the HPTE */ hptep->r = (hptep->r & ~(HPTE_R_PP | HPTE_R_N)) | (newpp & (HPTE_R_PP | HPTE_R_N)); /* Ensure it is out of the tlb too. */ tlbie(va, psize, ssize, 0); } static void native_hpte_invalidate(unsigned long slot, unsigned long va, int psize, 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(va=%016lx, hash: %x)\n", va, slot); want_v = hpte_encode_v(va, psize, ssize); native_lock_hpte(hptep); hpte_v = hptep->v; /* Even if we miss, we need to invalidate the TLB */ if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID)) native_unlock_hpte(hptep); else /* Invalidate the hpte. NOTE: this also unlocks it */ hptep->v = 0; /* Invalidate the TLB */ tlbie(va, psize, ssize, local); local_irq_restore(flags); } #define LP_SHIFT 12 #define LP_BITS 8 #define LP_MASK(i) ((0xFF >> (i)) << LP_SHIFT) static void hpte_decode(struct hash_pte *hpte, unsigned long slot, int *psize, int *ssize, unsigned long *va) { unsigned long hpte_r = hpte->r; unsigned long hpte_v = hpte->v; unsigned long avpn; int i, size, shift, penc; if (!(hpte_v & HPTE_V_LARGE)) size = MMU_PAGE_4K; else { for (i = 0; i < LP_BITS; i++) { if ((hpte_r & LP_MASK(i+1)) == LP_MASK(i+1)) break; } penc = LP_MASK(i+1) >> LP_SHIFT; for (size = 0; size < MMU_PAGE_COUNT; size++) { /* 4K pages are not represented by LP */ if (size == MMU_PAGE_4K) continue; /* valid entries have a shift value */ if (!mmu_psize_defs[size].shift) continue; if (penc == mmu_psize_defs[size].penc) break; } } /* This works for all page sizes, and for 256M and 1T segments */ shift = mmu_psize_defs[size].shift; avpn = (HPTE_V_AVPN_VAL(hpte_v) & ~mmu_psize_defs[size].avpnm) << 23; if (shift < 23) { unsigned long vpi, vsid, pteg; pteg = slot / HPTES_PER_GROUP; if (hpte_v & HPTE_V_SECONDARY) pteg = ~pteg; switch (hpte_v >> HPTE_V_SSIZE_SHIFT) { case MMU_SEGSIZE_256M: vpi = ((avpn >> 28) ^ pteg) & htab_hash_mask; break; case MMU_SEGSIZE_1T: vsid = avpn >> 40; vpi = (vsid ^ (vsid << 25) ^ pteg) & htab_hash_mask; break; default: avpn = vpi = size = 0; } avpn |= (vpi << mmu_psize_defs[size].shift); } *va = avpn; *psize = size; *ssize = hpte_v >> HPTE_V_SSIZE_SHIFT; } /* * 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; struct hash_pte *hptep = htab_address; unsigned long hpte_v, va; unsigned long pteg_count; int psize, ssize; 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; /* * Call __tlbie() here rather than tlbie() since we * already hold the native_tlbie_lock. */ if (hpte_v & HPTE_V_VALID) { hpte_decode(hptep, slot, &psize, &ssize, &va); hptep->v = 0; __tlbie(va, psize, ssize); } } asm volatile("eieio; tlbsync; ptesync":::"memory"); spin_unlock(&native_tlbie_lock); local_irq_restore(flags); } /* * 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 va, 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 = &__get_cpu_var(ppc64_tlb_batch); unsigned long psize = batch->psize; int ssize = batch->ssize; int i; local_irq_save(flags); 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; hptep = htab_address + slot; want_v = hpte_encode_v(va, psize, ssize); native_lock_hpte(hptep); hpte_v = hptep->v; if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID)) native_unlock_hpte(hptep); else hptep->v = 0; } pte_iterate_hashed_end(); } if (cpu_has_feature(CPU_FTR_TLBIEL) && mmu_psize_defs[psize].tlbiel && local) { asm volatile("ptesync":::"memory"); for (i = 0; i < number; i++) { va = batch->vaddr[i]; pte = batch->pte[i]; pte_iterate_hashed_subpages(pte, psize, va, index, shift) { __tlbiel(va, psize, ssize); } pte_iterate_hashed_end(); } 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 < number; i++) { va = batch->vaddr[i]; pte = batch->pte[i]; pte_iterate_hashed_subpages(pte, psize, va, index, shift) { __tlbie(va, psize, ssize); } pte_iterate_hashed_end(); } 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 = of_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 __init 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; }