/* * 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/of.h> #include <linux/threads.h> #include <linux/smp.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> #include <asm/ppc-opcode.h> #ifdef DEBUG_LOW #define DBG_LOW(fmt...) udbg_printf(fmt) #else #define DBG_LOW(fmt...) #endif #define HPTE_LOCK_BIT 3 DEFINE_RAW_SPINLOCK(native_tlbie_lock); static inline void __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 accomadate 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. */ 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 = ((mmu_psize_defs[apsize].sllp & SLB_VSID_L) >> 6) | ((mmu_psize_defs[apsize].sllp & SLB_VSID_LP) >> 4); 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; /* Add AVAL part */ if (psize != apsize) { /* * MPSS, 64K base page size and 16MB parge page size * 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_IFCLR("tlbie %0,1", PPC_TLBIE(%1,%0), %2) : : "r" (va), "r"(0), "i" (CPU_FTR_ARCH_206) : "memory"); break; } } 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. */ 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 = ((mmu_psize_defs[apsize].sllp & SLB_VSID_L) >> 6) | ((mmu_psize_defs[apsize].sllp & SLB_VSID_LP) >> 4); va |= sllp << 5; asm volatile(".long 0x7c000224 | (%0 << 11) | (0 << 21)" : : "r"(va) : "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; /* Add AVAL part */ if (psize != apsize) { /* * MPSS, 64K base page size and 16MB parge page size * 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(".long 0x7c000224 | (%0 << 11) | (1 << 21)" : : "r"(va) : "memory"); break; } } 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); asm volatile("ptesync": : :"memory"); } else { __tlbie(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 = &hptep->v; while (1) { if (!test_and_set_bit_lock(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; 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; int i; 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 (! (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(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); } 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 vpn, int bpsize, int apsize, int ssize, int local) { struct hash_pte *hptep = htab_address + slot; unsigned long hpte_v, want_v; int ret = 0; 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); native_lock_hpte(hptep); hpte_v = hptep->v; /* * 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 { 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(vpn, bpsize, apsize, ssize, local); return ret; } static long native_hpte_find(unsigned long vpn, 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(vpn, mmu_psize_defs[psize].shift, ssize); want_v = hpte_encode_avpn(vpn, 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 vpn; unsigned long vsid; long slot; struct hash_pte *hptep; 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 = (hptep->r & ~(HPTE_R_PP | HPTE_R_N)) | (newpp & (HPTE_R_PP | 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); } 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); native_lock_hpte(hptep); hpte_v = hptep->v; /* * 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)) native_unlock_hpte(hptep); else /* Invalidate the hpte. NOTE: this also unlocks it */ hptep->v = 0; /* Invalidate the TLB */ tlbie(vpn, bpsize, apsize, ssize, local); local_irq_restore(flags); } static void native_hugepage_invalidate(struct mm_struct *mm, unsigned char *hpte_slot_array, unsigned long addr, int psize) { int ssize = 0, i; int lock_tlbie; 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, vsid, 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)); if (!is_kernel_addr(addr)) { ssize = user_segment_size(addr); vsid = get_vsid(mm->context.id, addr, ssize); WARN_ON(vsid == 0); } else { vsid = get_kernel_vsid(addr, mmu_kernel_ssize); ssize = mmu_kernel_ssize; } 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); 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; } /* * Since this is a hugepage, we just need a single tlbie. * use the last vpn. */ lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE); if (lock_tlbie) raw_spin_lock(&native_tlbie_lock); asm volatile("ptesync":::"memory"); __tlbie(vpn, psize, actual_psize, ssize); asm volatile("eieio; tlbsync; ptesync":::"memory"); if (lock_tlbie) raw_spin_unlock(&native_tlbie_lock); local_irq_restore(flags); } static inline int __hpte_actual_psize(unsigned int lp, int psize) { int i, shift; unsigned int mask; /* start from 1 ignoring MMU_PAGE_4K */ for (i = 1; i < MMU_PAGE_COUNT; i++) { /* invalid penc */ if (mmu_psize_defs[psize].penc[i] == -1) continue; /* * encoding bits per actual page size * PTE LP actual page size * rrrr rrrz >=8KB * rrrr rrzz >=16KB * rrrr rzzz >=32KB * rrrr zzzz >=64KB * ....... */ shift = mmu_psize_defs[i].shift - LP_SHIFT; if (shift > LP_BITS) shift = LP_BITS; mask = (1 << shift) - 1; if ((lp & mask) == mmu_psize_defs[psize].penc[i]) return i; } return -1; } 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 = hpte->v; 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 (!(hpte_v & HPTE_V_LARGE)) { size = MMU_PAGE_4K; a_size = MMU_PAGE_4K; } else { for (size = 0; size < MMU_PAGE_COUNT; size++) { /* valid entries have a shift value */ if (!mmu_psize_defs[size].shift) continue; a_size = __hpte_actual_psize(lp, size); if (a_size != -1) break; } } /* 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. * * 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 vpn = 0; unsigned long slot, slots, flags; struct hash_pte *hptep = htab_address; unsigned long hpte_v; unsigned long pteg_count; int psize, apsize, 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. */ raw_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, &apsize, &ssize, &vpn); hptep->v = 0; __tlbie(vpn, psize, apsize, ssize); } } asm volatile("eieio; tlbsync; ptesync":::"memory"); raw_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 vpn; 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 = &__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++) { 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); 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 (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(); } asm volatile("ptesync":::"memory"); } 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(); } 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) { 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; ppc_md.flush_hash_range = native_flush_hash_range; ppc_md.hugepage_invalidate = native_hugepage_invalidate; }