diff options
Diffstat (limited to 'arch/powerpc/mm/book3s32')
| -rw-r--r-- | arch/powerpc/mm/book3s32/Makefile | 9 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s32/hash_low.S | 709 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s32/mmu.c | 470 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s32/mmu_context.c | 113 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s32/tlb.c | 171 |
5 files changed, 1472 insertions, 0 deletions
diff --git a/arch/powerpc/mm/book3s32/Makefile b/arch/powerpc/mm/book3s32/Makefile new file mode 100644 index 000000000..1732eaa74 --- /dev/null +++ b/arch/powerpc/mm/book3s32/Makefile @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0 + +KASAN_SANITIZE_mmu.o := n + +ifdef CONFIG_KASAN +CFLAGS_mmu.o += -DDISABLE_BRANCH_PROFILING +endif + +obj-y += mmu.o hash_low.o mmu_context.o tlb.o diff --git a/arch/powerpc/mm/book3s32/hash_low.S b/arch/powerpc/mm/book3s32/hash_low.S new file mode 100644 index 000000000..b2c912e51 --- /dev/null +++ b/arch/powerpc/mm/book3s32/hash_low.S @@ -0,0 +1,709 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * PowerPC version + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP + * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu> + * Adapted for Power Macintosh by Paul Mackerras. + * Low-level exception handlers and MMU support + * rewritten by Paul Mackerras. + * Copyright (C) 1996 Paul Mackerras. + * + * This file contains low-level assembler routines for managing + * the PowerPC MMU hash table. (PPC 8xx processors don't use a + * hash table, so this file is not used on them.) + */ + +#include <linux/pgtable.h> +#include <linux/init.h> +#include <asm/reg.h> +#include <asm/page.h> +#include <asm/cputable.h> +#include <asm/ppc_asm.h> +#include <asm/thread_info.h> +#include <asm/asm-offsets.h> +#include <asm/export.h> +#include <asm/feature-fixups.h> +#include <asm/code-patching-asm.h> + +#ifdef CONFIG_SMP + .section .bss + .align 2 +mmu_hash_lock: + .space 4 +#endif /* CONFIG_SMP */ + +/* + * Load a PTE into the hash table, if possible. + * The address is in r4, and r3 contains an access flag: + * _PAGE_RW (0x400) if a write. + * r9 contains the SRR1 value, from which we use the MSR_PR bit. + * SPRG_THREAD contains the physical address of the current task's thread. + * + * Returns to the caller if the access is illegal or there is no + * mapping for the address. Otherwise it places an appropriate PTE + * in the hash table and returns from the exception. + * Uses r0, r3 - r6, r8, r10, ctr, lr. + */ + .text +_GLOBAL(hash_page) +#ifdef CONFIG_SMP + lis r8, (mmu_hash_lock - PAGE_OFFSET)@h + ori r8, r8, (mmu_hash_lock - PAGE_OFFSET)@l + lis r0,0x0fff + b 10f +11: lwz r6,0(r8) + cmpwi 0,r6,0 + bne 11b +10: lwarx r6,0,r8 + cmpwi 0,r6,0 + bne- 11b + stwcx. r0,0,r8 + bne- 10b + isync +#endif + /* Get PTE (linux-style) and check access */ + lis r0, TASK_SIZE@h /* check if kernel address */ + cmplw 0,r4,r0 + ori r3,r3,_PAGE_USER|_PAGE_PRESENT /* test low addresses as user */ + mfspr r5, SPRN_SPRG_PGDIR /* phys page-table root */ + blt+ 112f /* assume user more likely */ + lis r5, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */ + addi r5 ,r5 ,(swapper_pg_dir - PAGE_OFFSET)@l /* kernel page table */ + rlwimi r3,r9,32-12,29,29 /* MSR_PR -> _PAGE_USER */ +112: +#ifndef CONFIG_PTE_64BIT + rlwimi r5,r4,12,20,29 /* insert top 10 bits of address */ + lwz r8,0(r5) /* get pmd entry */ + rlwinm. r8,r8,0,0,19 /* extract address of pte page */ +#else + rlwinm r8,r4,13,19,29 /* Compute pgdir/pmd offset */ + lwzx r8,r8,r5 /* Get L1 entry */ + rlwinm. r8,r8,0,0,20 /* extract pt base address */ +#endif +#ifdef CONFIG_SMP + beq- .Lhash_page_out /* return if no mapping */ +#else + /* XXX it seems like the 601 will give a machine fault on the + rfi if its alignment is wrong (bottom 4 bits of address are + 8 or 0xc) and we have had a not-taken conditional branch + to the address following the rfi. */ + beqlr- +#endif +#ifndef CONFIG_PTE_64BIT + rlwimi r8,r4,22,20,29 /* insert next 10 bits of address */ +#else + rlwimi r8,r4,23,20,28 /* compute pte address */ +#endif + rlwinm r0,r3,32-3,24,24 /* _PAGE_RW access -> _PAGE_DIRTY */ + ori r0,r0,_PAGE_ACCESSED|_PAGE_HASHPTE + + /* + * Update the linux PTE atomically. We do the lwarx up-front + * because almost always, there won't be a permission violation + * and there won't already be an HPTE, and thus we will have + * to update the PTE to set _PAGE_HASHPTE. -- paulus. + * + * If PTE_64BIT is set, the low word is the flags word; use that + * word for locking since it contains all the interesting bits. + */ +#if (PTE_FLAGS_OFFSET != 0) + addi r8,r8,PTE_FLAGS_OFFSET +#endif +.Lretry: + lwarx r6,0,r8 /* get linux-style pte, flag word */ + andc. r5,r3,r6 /* check access & ~permission */ +#ifdef CONFIG_SMP + bne- .Lhash_page_out /* return if access not permitted */ +#else + bnelr- +#endif + or r5,r0,r6 /* set accessed/dirty bits */ +#ifdef CONFIG_PTE_64BIT +#ifdef CONFIG_SMP + subf r10,r6,r8 /* create false data dependency */ + subi r10,r10,PTE_FLAGS_OFFSET + lwzx r10,r6,r10 /* Get upper PTE word */ +#else + lwz r10,-PTE_FLAGS_OFFSET(r8) +#endif /* CONFIG_SMP */ +#endif /* CONFIG_PTE_64BIT */ + stwcx. r5,0,r8 /* attempt to update PTE */ + bne- .Lretry /* retry if someone got there first */ + + mfsrin r3,r4 /* get segment reg for segment */ +#ifndef CONFIG_VMAP_STACK + mfctr r0 + stw r0,_CTR(r11) +#endif + bl create_hpte /* add the hash table entry */ + +#ifdef CONFIG_SMP + eieio + lis r8, (mmu_hash_lock - PAGE_OFFSET)@ha + li r0,0 + stw r0, (mmu_hash_lock - PAGE_OFFSET)@l(r8) +#endif + +#ifdef CONFIG_VMAP_STACK + b fast_hash_page_return +#else + /* Return from the exception */ + lwz r5,_CTR(r11) + mtctr r5 + lwz r0,GPR0(r11) + lwz r8,GPR8(r11) + b fast_exception_return +#endif + +#ifdef CONFIG_SMP +.Lhash_page_out: + eieio + lis r8, (mmu_hash_lock - PAGE_OFFSET)@ha + li r0,0 + stw r0, (mmu_hash_lock - PAGE_OFFSET)@l(r8) + blr +#endif /* CONFIG_SMP */ +_ASM_NOKPROBE_SYMBOL(hash_page) + +/* + * Add an entry for a particular page to the hash table. + * + * add_hash_page(unsigned context, unsigned long va, unsigned long pmdval) + * + * We assume any necessary modifications to the pte (e.g. setting + * the accessed bit) have already been done and that there is actually + * a hash table in use (i.e. we're not on a 603). + */ +_GLOBAL(add_hash_page) + mflr r0 + stw r0,4(r1) + + /* Convert context and va to VSID */ + mulli r3,r3,897*16 /* multiply context by context skew */ + rlwinm r0,r4,4,28,31 /* get ESID (top 4 bits of va) */ + mulli r0,r0,0x111 /* multiply by ESID skew */ + add r3,r3,r0 /* note create_hpte trims to 24 bits */ + +#ifdef CONFIG_SMP + lwz r8,TASK_CPU(r2) /* to go in mmu_hash_lock */ + oris r8,r8,12 +#endif /* CONFIG_SMP */ + + /* + * We disable interrupts here, even on UP, because we don't + * want to race with hash_page, and because we want the + * _PAGE_HASHPTE bit to be a reliable indication of whether + * the HPTE exists (or at least whether one did once). + * We also turn off the MMU for data accesses so that we + * we can't take a hash table miss (assuming the code is + * covered by a BAT). -- paulus + */ + mfmsr r9 + rlwinm r0,r9,0,17,15 /* clear bit 16 (MSR_EE) */ + rlwinm r0,r0,0,28,26 /* clear MSR_DR */ + mtmsr r0 + isync + +#ifdef CONFIG_SMP + lis r6, (mmu_hash_lock - PAGE_OFFSET)@ha + addi r6, r6, (mmu_hash_lock - PAGE_OFFSET)@l +10: lwarx r0,0,r6 /* take the mmu_hash_lock */ + cmpi 0,r0,0 + bne- 11f + stwcx. r8,0,r6 + beq+ 12f +11: lwz r0,0(r6) + cmpi 0,r0,0 + beq 10b + b 11b +12: isync +#endif + + /* + * Fetch the linux pte and test and set _PAGE_HASHPTE atomically. + * If _PAGE_HASHPTE was already set, we don't replace the existing + * HPTE, so we just unlock and return. + */ + mr r8,r5 +#ifndef CONFIG_PTE_64BIT + rlwimi r8,r4,22,20,29 +#else + rlwimi r8,r4,23,20,28 + addi r8,r8,PTE_FLAGS_OFFSET +#endif +1: lwarx r6,0,r8 + andi. r0,r6,_PAGE_HASHPTE + bne 9f /* if HASHPTE already set, done */ +#ifdef CONFIG_PTE_64BIT +#ifdef CONFIG_SMP + subf r10,r6,r8 /* create false data dependency */ + subi r10,r10,PTE_FLAGS_OFFSET + lwzx r10,r6,r10 /* Get upper PTE word */ +#else + lwz r10,-PTE_FLAGS_OFFSET(r8) +#endif /* CONFIG_SMP */ +#endif /* CONFIG_PTE_64BIT */ + ori r5,r6,_PAGE_HASHPTE + stwcx. r5,0,r8 + bne- 1b + + bl create_hpte + +9: +#ifdef CONFIG_SMP + lis r6, (mmu_hash_lock - PAGE_OFFSET)@ha + addi r6, r6, (mmu_hash_lock - PAGE_OFFSET)@l + eieio + li r0,0 + stw r0,0(r6) /* clear mmu_hash_lock */ +#endif + + /* reenable interrupts and DR */ + mtmsr r9 + isync + + lwz r0,4(r1) + mtlr r0 + blr +_ASM_NOKPROBE_SYMBOL(add_hash_page) + +/* + * This routine adds a hardware PTE to the hash table. + * It is designed to be called with the MMU either on or off. + * r3 contains the VSID, r4 contains the virtual address, + * r5 contains the linux PTE, r6 contains the old value of the + * linux PTE (before setting _PAGE_HASHPTE). r10 contains the + * upper half of the PTE if CONFIG_PTE_64BIT. + * On SMP, the caller should have the mmu_hash_lock held. + * We assume that the caller has (or will) set the _PAGE_HASHPTE + * bit in the linux PTE in memory. The value passed in r6 should + * be the old linux PTE value; if it doesn't have _PAGE_HASHPTE set + * this routine will skip the search for an existing HPTE. + * This procedure modifies r0, r3 - r6, r8, cr0. + * -- paulus. + * + * For speed, 4 of the instructions get patched once the size and + * physical address of the hash table are known. These definitions + * of Hash_base and Hash_bits below are for the early hash table. + */ +Hash_base = early_hash +Hash_bits = 12 /* e.g. 256kB hash table */ +Hash_msk = (((1 << Hash_bits) - 1) * 64) + +/* defines for the PTE format for 32-bit PPCs */ +#define HPTE_SIZE 8 +#define PTEG_SIZE 64 +#define LG_PTEG_SIZE 6 +#define LDPTEu lwzu +#define LDPTE lwz +#define STPTE stw +#define CMPPTE cmpw +#define PTE_H 0x40 +#define PTE_V 0x80000000 +#define TST_V(r) rlwinm. r,r,0,0,0 +#define SET_V(r) oris r,r,PTE_V@h +#define CLR_V(r,t) rlwinm r,r,0,1,31 + +#define HASH_LEFT 31-(LG_PTEG_SIZE+Hash_bits-1) +#define HASH_RIGHT 31-LG_PTEG_SIZE + +__REF +_GLOBAL(create_hpte) + /* Convert linux-style PTE (r5) to low word of PPC-style PTE (r8) */ + rlwinm r8,r5,32-9,30,30 /* _PAGE_RW -> PP msb */ + rlwinm r0,r5,32-6,30,30 /* _PAGE_DIRTY -> PP msb */ + and r8,r8,r0 /* writable if _RW & _DIRTY */ + rlwimi r5,r5,32-1,30,30 /* _PAGE_USER -> PP msb */ + rlwimi r5,r5,32-2,31,31 /* _PAGE_USER -> PP lsb */ + ori r8,r8,0xe04 /* clear out reserved bits */ + andc r8,r5,r8 /* PP = user? (rw&dirty? 1: 3): 0 */ +BEGIN_FTR_SECTION + rlwinm r8,r8,0,~_PAGE_COHERENT /* clear M (coherence not required) */ +END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT) +#ifdef CONFIG_PTE_64BIT + /* Put the XPN bits into the PTE */ + rlwimi r8,r10,8,20,22 + rlwimi r8,r10,2,29,29 +#endif + + /* Construct the high word of the PPC-style PTE (r5) */ + rlwinm r5,r3,7,1,24 /* put VSID in 0x7fffff80 bits */ + rlwimi r5,r4,10,26,31 /* put in API (abbrev page index) */ + SET_V(r5) /* set V (valid) bit */ + + patch_site 0f, patch__hash_page_A0 + patch_site 1f, patch__hash_page_A1 + patch_site 2f, patch__hash_page_A2 + /* Get the address of the primary PTE group in the hash table (r3) */ +0: lis r0, (Hash_base - PAGE_OFFSET)@h /* base address of hash table */ +1: rlwimi r0,r3,LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT /* VSID -> hash */ +2: rlwinm r3,r4,20+LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT /* PI -> hash */ + xor r3,r3,r0 /* make primary hash */ + li r0,8 /* PTEs/group */ + + /* + * Test the _PAGE_HASHPTE bit in the old linux PTE, and skip the search + * if it is clear, meaning that the HPTE isn't there already... + */ + andi. r6,r6,_PAGE_HASHPTE + beq+ 10f /* no PTE: go look for an empty slot */ + tlbie r4 + + lis r4, (htab_hash_searches - PAGE_OFFSET)@ha + lwz r6, (htab_hash_searches - PAGE_OFFSET)@l(r4) + addi r6,r6,1 /* count how many searches we do */ + stw r6, (htab_hash_searches - PAGE_OFFSET)@l(r4) + + /* Search the primary PTEG for a PTE whose 1st (d)word matches r5 */ + mtctr r0 + addi r4,r3,-HPTE_SIZE +1: LDPTEu r6,HPTE_SIZE(r4) /* get next PTE */ + CMPPTE 0,r6,r5 + bdnzf 2,1b /* loop while ctr != 0 && !cr0.eq */ + beq+ .Lfound_slot + + patch_site 0f, patch__hash_page_B + /* Search the secondary PTEG for a matching PTE */ + ori r5,r5,PTE_H /* set H (secondary hash) bit */ +0: xoris r4,r3,Hash_msk>>16 /* compute secondary hash */ + xori r4,r4,(-PTEG_SIZE & 0xffff) + addi r4,r4,-HPTE_SIZE + mtctr r0 +2: LDPTEu r6,HPTE_SIZE(r4) + CMPPTE 0,r6,r5 + bdnzf 2,2b + beq+ .Lfound_slot + xori r5,r5,PTE_H /* clear H bit again */ + + /* Search the primary PTEG for an empty slot */ +10: mtctr r0 + addi r4,r3,-HPTE_SIZE /* search primary PTEG */ +1: LDPTEu r6,HPTE_SIZE(r4) /* get next PTE */ + TST_V(r6) /* test valid bit */ + bdnzf 2,1b /* loop while ctr != 0 && !cr0.eq */ + beq+ .Lfound_empty + + /* update counter of times that the primary PTEG is full */ + lis r4, (primary_pteg_full - PAGE_OFFSET)@ha + lwz r6, (primary_pteg_full - PAGE_OFFSET)@l(r4) + addi r6,r6,1 + stw r6, (primary_pteg_full - PAGE_OFFSET)@l(r4) + + patch_site 0f, patch__hash_page_C + /* Search the secondary PTEG for an empty slot */ + ori r5,r5,PTE_H /* set H (secondary hash) bit */ +0: xoris r4,r3,Hash_msk>>16 /* compute secondary hash */ + xori r4,r4,(-PTEG_SIZE & 0xffff) + addi r4,r4,-HPTE_SIZE + mtctr r0 +2: LDPTEu r6,HPTE_SIZE(r4) + TST_V(r6) + bdnzf 2,2b + beq+ .Lfound_empty + xori r5,r5,PTE_H /* clear H bit again */ + + /* + * Choose an arbitrary slot in the primary PTEG to overwrite. + * Since both the primary and secondary PTEGs are full, and we + * have no information that the PTEs in the primary PTEG are + * more important or useful than those in the secondary PTEG, + * and we know there is a definite (although small) speed + * advantage to putting the PTE in the primary PTEG, we always + * put the PTE in the primary PTEG. + * + * In addition, we skip any slot that is mapping kernel text in + * order to avoid a deadlock when not using BAT mappings if + * trying to hash in the kernel hash code itself after it has + * already taken the hash table lock. This works in conjunction + * with pre-faulting of the kernel text. + * + * If the hash table bucket is full of kernel text entries, we'll + * lockup here but that shouldn't happen + */ + +1: lis r4, (next_slot - PAGE_OFFSET)@ha /* get next evict slot */ + lwz r6, (next_slot - PAGE_OFFSET)@l(r4) + addi r6,r6,HPTE_SIZE /* search for candidate */ + andi. r6,r6,7*HPTE_SIZE + stw r6,next_slot@l(r4) + add r4,r3,r6 + LDPTE r0,HPTE_SIZE/2(r4) /* get PTE second word */ + clrrwi r0,r0,12 + lis r6,etext@h + ori r6,r6,etext@l /* get etext */ + tophys(r6,r6) + cmpl cr0,r0,r6 /* compare and try again */ + blt 1b + +#ifndef CONFIG_SMP + /* Store PTE in PTEG */ +.Lfound_empty: + STPTE r5,0(r4) +.Lfound_slot: + STPTE r8,HPTE_SIZE/2(r4) + +#else /* CONFIG_SMP */ +/* + * Between the tlbie above and updating the hash table entry below, + * another CPU could read the hash table entry and put it in its TLB. + * There are 3 cases: + * 1. using an empty slot + * 2. updating an earlier entry to change permissions (i.e. enable write) + * 3. taking over the PTE for an unrelated address + * + * In each case it doesn't really matter if the other CPUs have the old + * PTE in their TLB. So we don't need to bother with another tlbie here, + * which is convenient as we've overwritten the register that had the + * address. :-) The tlbie above is mainly to make sure that this CPU comes + * and gets the new PTE from the hash table. + * + * We do however have to make sure that the PTE is never in an invalid + * state with the V bit set. + */ +.Lfound_empty: +.Lfound_slot: + CLR_V(r5,r0) /* clear V (valid) bit in PTE */ + STPTE r5,0(r4) + sync + TLBSYNC + STPTE r8,HPTE_SIZE/2(r4) /* put in correct RPN, WIMG, PP bits */ + sync + SET_V(r5) + STPTE r5,0(r4) /* finally set V bit in PTE */ +#endif /* CONFIG_SMP */ + + sync /* make sure pte updates get to memory */ + blr + .previous +_ASM_NOKPROBE_SYMBOL(create_hpte) + + .section .bss + .align 2 +next_slot: + .space 4 +primary_pteg_full: + .space 4 +htab_hash_searches: + .space 4 + .previous + +/* + * Flush the entry for a particular page from the hash table. + * + * flush_hash_pages(unsigned context, unsigned long va, unsigned long pmdval, + * int count) + * + * We assume that there is a hash table in use (Hash != 0). + */ +__REF +_GLOBAL(flush_hash_pages) + /* + * We disable interrupts here, even on UP, because we want + * the _PAGE_HASHPTE bit to be a reliable indication of + * whether the HPTE exists (or at least whether one did once). + * We also turn off the MMU for data accesses so that we + * we can't take a hash table miss (assuming the code is + * covered by a BAT). -- paulus + */ + mfmsr r10 + rlwinm r0,r10,0,17,15 /* clear bit 16 (MSR_EE) */ + rlwinm r0,r0,0,28,26 /* clear MSR_DR */ + mtmsr r0 + isync + + /* First find a PTE in the range that has _PAGE_HASHPTE set */ +#ifndef CONFIG_PTE_64BIT + rlwimi r5,r4,22,20,29 +#else + rlwimi r5,r4,23,20,28 +#endif +1: lwz r0,PTE_FLAGS_OFFSET(r5) + cmpwi cr1,r6,1 + andi. r0,r0,_PAGE_HASHPTE + bne 2f + ble cr1,19f + addi r4,r4,0x1000 + addi r5,r5,PTE_SIZE + addi r6,r6,-1 + b 1b + + /* Convert context and va to VSID */ +2: mulli r3,r3,897*16 /* multiply context by context skew */ + rlwinm r0,r4,4,28,31 /* get ESID (top 4 bits of va) */ + mulli r0,r0,0x111 /* multiply by ESID skew */ + add r3,r3,r0 /* note code below trims to 24 bits */ + + /* Construct the high word of the PPC-style PTE (r11) */ + rlwinm r11,r3,7,1,24 /* put VSID in 0x7fffff80 bits */ + rlwimi r11,r4,10,26,31 /* put in API (abbrev page index) */ + SET_V(r11) /* set V (valid) bit */ + +#ifdef CONFIG_SMP + lis r9, (mmu_hash_lock - PAGE_OFFSET)@ha + addi r9, r9, (mmu_hash_lock - PAGE_OFFSET)@l + tophys (r8, r2) + lwz r8, TASK_CPU(r8) + oris r8,r8,9 +10: lwarx r0,0,r9 + cmpi 0,r0,0 + bne- 11f + stwcx. r8,0,r9 + beq+ 12f +11: lwz r0,0(r9) + cmpi 0,r0,0 + beq 10b + b 11b +12: isync +#endif + + /* + * Check the _PAGE_HASHPTE bit in the linux PTE. If it is + * already clear, we're done (for this pte). If not, + * clear it (atomically) and proceed. -- paulus. + */ +#if (PTE_FLAGS_OFFSET != 0) + addi r5,r5,PTE_FLAGS_OFFSET +#endif +33: lwarx r8,0,r5 /* fetch the pte flags word */ + andi. r0,r8,_PAGE_HASHPTE + beq 8f /* done if HASHPTE is already clear */ + rlwinm r8,r8,0,31,29 /* clear HASHPTE bit */ + stwcx. r8,0,r5 /* update the pte */ + bne- 33b + + patch_site 0f, patch__flush_hash_A0 + patch_site 1f, patch__flush_hash_A1 + patch_site 2f, patch__flush_hash_A2 + /* Get the address of the primary PTE group in the hash table (r3) */ +0: lis r8, (Hash_base - PAGE_OFFSET)@h /* base address of hash table */ +1: rlwimi r8,r3,LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT /* VSID -> hash */ +2: rlwinm r0,r4,20+LG_PTEG_SIZE,HASH_LEFT,HASH_RIGHT /* PI -> hash */ + xor r8,r0,r8 /* make primary hash */ + + /* Search the primary PTEG for a PTE whose 1st (d)word matches r5 */ + li r0,8 /* PTEs/group */ + mtctr r0 + addi r12,r8,-HPTE_SIZE +1: LDPTEu r0,HPTE_SIZE(r12) /* get next PTE */ + CMPPTE 0,r0,r11 + bdnzf 2,1b /* loop while ctr != 0 && !cr0.eq */ + beq+ 3f + + patch_site 0f, patch__flush_hash_B + /* Search the secondary PTEG for a matching PTE */ + ori r11,r11,PTE_H /* set H (secondary hash) bit */ + li r0,8 /* PTEs/group */ +0: xoris r12,r8,Hash_msk>>16 /* compute secondary hash */ + xori r12,r12,(-PTEG_SIZE & 0xffff) + addi r12,r12,-HPTE_SIZE + mtctr r0 +2: LDPTEu r0,HPTE_SIZE(r12) + CMPPTE 0,r0,r11 + bdnzf 2,2b + xori r11,r11,PTE_H /* clear H again */ + bne- 4f /* should rarely fail to find it */ + +3: li r0,0 + STPTE r0,0(r12) /* invalidate entry */ +4: sync + tlbie r4 /* in hw tlb too */ + sync + +8: ble cr1,9f /* if all ptes checked */ +81: addi r6,r6,-1 + addi r5,r5,PTE_SIZE + addi r4,r4,0x1000 + lwz r0,0(r5) /* check next pte */ + cmpwi cr1,r6,1 + andi. r0,r0,_PAGE_HASHPTE + bne 33b + bgt cr1,81b + +9: +#ifdef CONFIG_SMP + TLBSYNC + li r0,0 + stw r0,0(r9) /* clear mmu_hash_lock */ +#endif + +19: mtmsr r10 + isync + blr + .previous +EXPORT_SYMBOL(flush_hash_pages) +_ASM_NOKPROBE_SYMBOL(flush_hash_pages) + +/* + * Flush an entry from the TLB + */ +_GLOBAL(_tlbie) +#ifdef CONFIG_SMP + lwz r8,TASK_CPU(r2) + oris r8,r8,11 + mfmsr r10 + rlwinm r0,r10,0,17,15 /* clear bit 16 (MSR_EE) */ + rlwinm r0,r0,0,28,26 /* clear DR */ + mtmsr r0 + isync + lis r9,mmu_hash_lock@h + ori r9,r9,mmu_hash_lock@l + tophys(r9,r9) +10: lwarx r7,0,r9 + cmpwi 0,r7,0 + bne- 10b + stwcx. r8,0,r9 + bne- 10b + eieio + tlbie r3 + sync + TLBSYNC + li r0,0 + stw r0,0(r9) /* clear mmu_hash_lock */ + mtmsr r10 + isync +#else /* CONFIG_SMP */ + tlbie r3 + sync +#endif /* CONFIG_SMP */ + blr +_ASM_NOKPROBE_SYMBOL(_tlbie) + +/* + * Flush the entire TLB. 603/603e only + */ +_GLOBAL(_tlbia) +#if defined(CONFIG_SMP) + lwz r8,TASK_CPU(r2) + oris r8,r8,10 + mfmsr r10 + rlwinm r0,r10,0,17,15 /* clear bit 16 (MSR_EE) */ + rlwinm r0,r0,0,28,26 /* clear DR */ + mtmsr r0 + isync + lis r9,mmu_hash_lock@h + ori r9,r9,mmu_hash_lock@l + tophys(r9,r9) +10: lwarx r7,0,r9 + cmpwi 0,r7,0 + bne- 10b + stwcx. r8,0,r9 + bne- 10b +#endif /* CONFIG_SMP */ + li r5, 32 + lis r4, KERNELBASE@h + mtctr r5 + sync +0: tlbie r4 + addi r4, r4, 0x1000 + bdnz 0b + sync +#ifdef CONFIG_SMP + TLBSYNC + li r0,0 + stw r0,0(r9) /* clear mmu_hash_lock */ + mtmsr r10 + isync +#endif /* CONFIG_SMP */ + blr +_ASM_NOKPROBE_SYMBOL(_tlbia) diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c new file mode 100644 index 000000000..602ab1312 --- /dev/null +++ b/arch/powerpc/mm/book3s32/mmu.c @@ -0,0 +1,470 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * This file contains the routines for handling the MMU on those + * PowerPC implementations where the MMU substantially follows the + * architecture specification. This includes the 6xx, 7xx, 7xxx, + * and 8260 implementations but excludes the 8xx and 4xx. + * -- paulus + * + * Derived from arch/ppc/mm/init.c: + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) + * and Cort Dougan (PReP) (cort@cs.nmt.edu) + * Copyright (C) 1996 Paul Mackerras + * + * Derived from "arch/i386/mm/init.c" + * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds + */ + +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/highmem.h> +#include <linux/memblock.h> + +#include <asm/prom.h> +#include <asm/mmu.h> +#include <asm/machdep.h> +#include <asm/code-patching.h> +#include <asm/sections.h> + +#include <mm/mmu_decl.h> + +u8 __initdata early_hash[SZ_256K] __aligned(SZ_256K) = {0}; + +struct hash_pte *Hash; +static unsigned long Hash_size, Hash_mask; +unsigned long _SDR1; +static unsigned int hash_mb, hash_mb2; + +struct ppc_bat BATS[8][2]; /* 8 pairs of IBAT, DBAT */ + +struct batrange { /* stores address ranges mapped by BATs */ + unsigned long start; + unsigned long limit; + phys_addr_t phys; +} bat_addrs[8]; + +/* + * Return PA for this VA if it is mapped by a BAT, or 0 + */ +phys_addr_t v_block_mapped(unsigned long va) +{ + int b; + for (b = 0; b < ARRAY_SIZE(bat_addrs); ++b) + if (va >= bat_addrs[b].start && va < bat_addrs[b].limit) + return bat_addrs[b].phys + (va - bat_addrs[b].start); + return 0; +} + +/* + * Return VA for a given PA or 0 if not mapped + */ +unsigned long p_block_mapped(phys_addr_t pa) +{ + int b; + for (b = 0; b < ARRAY_SIZE(bat_addrs); ++b) + if (pa >= bat_addrs[b].phys + && pa < (bat_addrs[b].limit-bat_addrs[b].start) + +bat_addrs[b].phys) + return bat_addrs[b].start+(pa-bat_addrs[b].phys); + return 0; +} + +int __init find_free_bat(void) +{ + int b; + int n = mmu_has_feature(MMU_FTR_USE_HIGH_BATS) ? 8 : 4; + + for (b = 0; b < n; b++) { + struct ppc_bat *bat = BATS[b]; + + if (!(bat[1].batu & 3)) + return b; + } + return -1; +} + +/* + * This function calculates the size of the larger block usable to map the + * beginning of an area based on the start address and size of that area: + * - max block size is 256 on 6xx. + * - base address must be aligned to the block size. So the maximum block size + * is identified by the lowest bit set to 1 in the base address (for instance + * if base is 0x16000000, max size is 0x02000000). + * - block size has to be a power of two. This is calculated by finding the + * highest bit set to 1. + */ +unsigned int bat_block_size(unsigned long base, unsigned long top) +{ + unsigned int max_size = SZ_256M; + unsigned int base_shift = (ffs(base) - 1) & 31; + unsigned int block_shift = (fls(top - base) - 1) & 31; + + return min3(max_size, 1U << base_shift, 1U << block_shift); +} + +/* + * Set up one of the IBAT (block address translation) register pairs. + * The parameters are not checked; in particular size must be a power + * of 2 between 128k and 256M. + */ +static void setibat(int index, unsigned long virt, phys_addr_t phys, + unsigned int size, pgprot_t prot) +{ + unsigned int bl = (size >> 17) - 1; + int wimgxpp; + struct ppc_bat *bat = BATS[index]; + unsigned long flags = pgprot_val(prot); + + if (!cpu_has_feature(CPU_FTR_NEED_COHERENT)) + flags &= ~_PAGE_COHERENT; + + wimgxpp = (flags & _PAGE_COHERENT) | (_PAGE_EXEC ? BPP_RX : BPP_XX); + bat[0].batu = virt | (bl << 2) | 2; /* Vs=1, Vp=0 */ + bat[0].batl = BAT_PHYS_ADDR(phys) | wimgxpp; + if (flags & _PAGE_USER) + bat[0].batu |= 1; /* Vp = 1 */ +} + +static void clearibat(int index) +{ + struct ppc_bat *bat = BATS[index]; + + bat[0].batu = 0; + bat[0].batl = 0; +} + +static unsigned long __init __mmu_mapin_ram(unsigned long base, unsigned long top) +{ + int idx; + + while ((idx = find_free_bat()) != -1 && base != top) { + unsigned int size = bat_block_size(base, top); + + if (size < 128 << 10) + break; + setbat(idx, PAGE_OFFSET + base, base, size, PAGE_KERNEL_X); + base += size; + } + + return base; +} + +unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) +{ + unsigned long done; + unsigned long border = (unsigned long)__init_begin - PAGE_OFFSET; + + if (__map_without_bats) { + pr_debug("RAM mapped without BATs\n"); + return base; + } + if (debug_pagealloc_enabled()) { + if (base >= border) + return base; + if (top >= border) + top = border; + } + + if (!strict_kernel_rwx_enabled() || base >= border || top <= border) + return __mmu_mapin_ram(base, top); + + done = __mmu_mapin_ram(base, border); + if (done != border) + return done; + + return __mmu_mapin_ram(border, top); +} + +static bool is_module_segment(unsigned long addr) +{ + if (!IS_ENABLED(CONFIG_MODULES)) + return false; +#ifdef MODULES_VADDR + if (addr < ALIGN_DOWN(MODULES_VADDR, SZ_256M)) + return false; + if (addr > ALIGN(MODULES_END, SZ_256M) - 1) + return false; +#else + if (addr < ALIGN_DOWN(VMALLOC_START, SZ_256M)) + return false; + if (addr > ALIGN(VMALLOC_END, SZ_256M) - 1) + return false; +#endif + return true; +} + +void mmu_mark_initmem_nx(void) +{ + int nb = mmu_has_feature(MMU_FTR_USE_HIGH_BATS) ? 8 : 4; + int i; + unsigned long base = (unsigned long)_stext - PAGE_OFFSET; + unsigned long top = ALIGN((unsigned long)_etext - PAGE_OFFSET, SZ_128K); + unsigned long border = (unsigned long)__init_begin - PAGE_OFFSET; + unsigned long size; + + for (i = 0; i < nb - 1 && base < top;) { + size = bat_block_size(base, top); + setibat(i++, PAGE_OFFSET + base, base, size, PAGE_KERNEL_TEXT); + base += size; + } + if (base < top) { + size = bat_block_size(base, top); + if ((top - base) > size) { + size <<= 1; + if (strict_kernel_rwx_enabled() && base + size > border) + pr_warn("Some RW data is getting mapped X. " + "Adjust CONFIG_DATA_SHIFT to avoid that.\n"); + } + setibat(i++, PAGE_OFFSET + base, base, size, PAGE_KERNEL_TEXT); + base += size; + } + for (; i < nb; i++) + clearibat(i); + + update_bats(); + + for (i = TASK_SIZE >> 28; i < 16; i++) { + /* Do not set NX on VM space for modules */ + if (is_module_segment(i << 28)) + continue; + + mtsrin(mfsrin(i << 28) | 0x10000000, i << 28); + } +} + +void mmu_mark_rodata_ro(void) +{ + int nb = mmu_has_feature(MMU_FTR_USE_HIGH_BATS) ? 8 : 4; + int i; + + for (i = 0; i < nb; i++) { + struct ppc_bat *bat = BATS[i]; + + if (bat_addrs[i].start < (unsigned long)__init_begin) + bat[1].batl = (bat[1].batl & ~BPP_RW) | BPP_RX; + } + + update_bats(); +} + +/* + * Set up one of the I/D BAT (block address translation) register pairs. + * The parameters are not checked; in particular size must be a power + * of 2 between 128k and 256M. + * On 603+, only set IBAT when _PAGE_EXEC is set + */ +void __init setbat(int index, unsigned long virt, phys_addr_t phys, + unsigned int size, pgprot_t prot) +{ + unsigned int bl; + int wimgxpp; + struct ppc_bat *bat; + unsigned long flags = pgprot_val(prot); + + if (index == -1) + index = find_free_bat(); + if (index == -1) { + pr_err("%s: no BAT available for mapping 0x%llx\n", __func__, + (unsigned long long)phys); + return; + } + bat = BATS[index]; + + if ((flags & _PAGE_NO_CACHE) || + (cpu_has_feature(CPU_FTR_NEED_COHERENT) == 0)) + flags &= ~_PAGE_COHERENT; + + bl = (size >> 17) - 1; + /* Do DBAT first */ + wimgxpp = flags & (_PAGE_WRITETHRU | _PAGE_NO_CACHE + | _PAGE_COHERENT | _PAGE_GUARDED); + wimgxpp |= (flags & _PAGE_RW)? BPP_RW: BPP_RX; + bat[1].batu = virt | (bl << 2) | 2; /* Vs=1, Vp=0 */ + bat[1].batl = BAT_PHYS_ADDR(phys) | wimgxpp; + if (flags & _PAGE_USER) + bat[1].batu |= 1; /* Vp = 1 */ + if (flags & _PAGE_GUARDED) { + /* G bit must be zero in IBATs */ + flags &= ~_PAGE_EXEC; + } + if (flags & _PAGE_EXEC) + bat[0] = bat[1]; + else + bat[0].batu = bat[0].batl = 0; + + bat_addrs[index].start = virt; + bat_addrs[index].limit = virt + ((bl + 1) << 17) - 1; + bat_addrs[index].phys = phys; +} + +/* + * Preload a translation in the hash table + */ +void hash_preload(struct mm_struct *mm, unsigned long ea) +{ + pmd_t *pmd; + + if (!Hash) + return; + pmd = pmd_off(mm, ea); + if (!pmd_none(*pmd)) + add_hash_page(mm->context.id, ea, pmd_val(*pmd)); +} + +/* + * This is called at the end of handling a user page fault, when the + * fault has been handled by updating a PTE in the linux page tables. + * We use it to preload an HPTE into the hash table corresponding to + * the updated linux PTE. + * + * This must always be called with the pte lock held. + */ +void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, + pte_t *ptep) +{ + if (!mmu_has_feature(MMU_FTR_HPTE_TABLE)) + return; + /* + * We don't need to worry about _PAGE_PRESENT here because we are + * called with either mm->page_table_lock held or ptl lock held + */ + + /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */ + if (!pte_young(*ptep) || address >= TASK_SIZE) + return; + + /* We have to test for regs NULL since init will get here first thing at boot */ + if (!current->thread.regs) + return; + + /* We also avoid filling the hash if not coming from a fault */ + if (TRAP(current->thread.regs) != 0x300 && TRAP(current->thread.regs) != 0x400) + return; + + hash_preload(vma->vm_mm, address); +} + +/* + * Initialize the hash table and patch the instructions in hashtable.S. + */ +void __init MMU_init_hw(void) +{ + unsigned int n_hpteg, lg_n_hpteg; + + if (!mmu_has_feature(MMU_FTR_HPTE_TABLE)) + return; + + if ( ppc_md.progress ) ppc_md.progress("hash:enter", 0x105); + +#define LG_HPTEG_SIZE 6 /* 64 bytes per HPTEG */ +#define SDR1_LOW_BITS ((n_hpteg - 1) >> 10) +#define MIN_N_HPTEG 1024 /* min 64kB hash table */ + + /* + * Allow 1 HPTE (1/8 HPTEG) for each page of memory. + * This is less than the recommended amount, but then + * Linux ain't AIX. + */ + n_hpteg = total_memory / (PAGE_SIZE * 8); + if (n_hpteg < MIN_N_HPTEG) + n_hpteg = MIN_N_HPTEG; + lg_n_hpteg = __ilog2(n_hpteg); + if (n_hpteg & (n_hpteg - 1)) { + ++lg_n_hpteg; /* round up if not power of 2 */ + n_hpteg = 1 << lg_n_hpteg; + } + Hash_size = n_hpteg << LG_HPTEG_SIZE; + + /* + * Find some memory for the hash table. + */ + if ( ppc_md.progress ) ppc_md.progress("hash:find piece", 0x322); + Hash = memblock_alloc(Hash_size, Hash_size); + if (!Hash) + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", + __func__, Hash_size, Hash_size); + _SDR1 = __pa(Hash) | SDR1_LOW_BITS; + + pr_info("Total memory = %lldMB; using %ldkB for hash table\n", + (unsigned long long)(total_memory >> 20), Hash_size >> 10); + + + Hash_mask = n_hpteg - 1; + hash_mb2 = hash_mb = 32 - LG_HPTEG_SIZE - lg_n_hpteg; + if (lg_n_hpteg > 16) + hash_mb2 = 16 - LG_HPTEG_SIZE; +} + +void __init MMU_init_hw_patch(void) +{ + unsigned int hmask = Hash_mask >> (16 - LG_HPTEG_SIZE); + unsigned int hash = (unsigned int)Hash - PAGE_OFFSET; + + if (!mmu_has_feature(MMU_FTR_HPTE_TABLE)) + return; + + if (ppc_md.progress) + ppc_md.progress("hash:patch", 0x345); + if (ppc_md.progress) + ppc_md.progress("hash:done", 0x205); + + /* WARNING: Make sure nothing can trigger a KASAN check past this point */ + + /* + * Patch up the instructions in hashtable.S:create_hpte + */ + modify_instruction_site(&patch__hash_page_A0, 0xffff, hash >> 16); + modify_instruction_site(&patch__hash_page_A1, 0x7c0, hash_mb << 6); + modify_instruction_site(&patch__hash_page_A2, 0x7c0, hash_mb2 << 6); + modify_instruction_site(&patch__hash_page_B, 0xffff, hmask); + modify_instruction_site(&patch__hash_page_C, 0xffff, hmask); + + /* + * Patch up the instructions in hashtable.S:flush_hash_page + */ + modify_instruction_site(&patch__flush_hash_A0, 0xffff, hash >> 16); + modify_instruction_site(&patch__flush_hash_A1, 0x7c0, hash_mb << 6); + modify_instruction_site(&patch__flush_hash_A2, 0x7c0, hash_mb2 << 6); + modify_instruction_site(&patch__flush_hash_B, 0xffff, hmask); +} + +void setup_initial_memory_limit(phys_addr_t first_memblock_base, + phys_addr_t first_memblock_size) +{ + /* We don't currently support the first MEMBLOCK not mapping 0 + * physical on those processors + */ + BUG_ON(first_memblock_base != 0); + + memblock_set_current_limit(min_t(u64, first_memblock_size, SZ_256M)); +} + +void __init print_system_hash_info(void) +{ + pr_info("Hash_size = 0x%lx\n", Hash_size); + if (Hash_mask) + pr_info("Hash_mask = 0x%lx\n", Hash_mask); +} + +#ifdef CONFIG_PPC_KUEP +void __init setup_kuep(bool disabled) +{ + pr_info("Activating Kernel Userspace Execution Prevention\n"); + + if (disabled) + pr_warn("KUEP cannot be disabled yet on 6xx when compiled in\n"); +} +#endif + +#ifdef CONFIG_PPC_KUAP +void __init setup_kuap(bool disabled) +{ + pr_info("Activating Kernel Userspace Access Protection\n"); + + if (disabled) + pr_warn("KUAP cannot be disabled yet on 6xx when compiled in\n"); +} +#endif diff --git a/arch/powerpc/mm/book3s32/mmu_context.c b/arch/powerpc/mm/book3s32/mmu_context.c new file mode 100644 index 000000000..218996e40 --- /dev/null +++ b/arch/powerpc/mm/book3s32/mmu_context.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * This file contains the routines for handling the MMU on those + * PowerPC implementations where the MMU substantially follows the + * architecture specification. This includes the 6xx, 7xx, 7xxx, + * and 8260 implementations but excludes the 8xx and 4xx. + * -- paulus + * + * Derived from arch/ppc/mm/init.c: + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) + * and Cort Dougan (PReP) (cort@cs.nmt.edu) + * Copyright (C) 1996 Paul Mackerras + * + * Derived from "arch/i386/mm/init.c" + * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds + */ + +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/export.h> + +#include <asm/mmu_context.h> + +/* + * On 32-bit PowerPC 6xx/7xx/7xxx CPUs, we use a set of 16 VSIDs + * (virtual segment identifiers) for each context. Although the + * hardware supports 24-bit VSIDs, and thus >1 million contexts, + * we only use 32,768 of them. That is ample, since there can be + * at most around 30,000 tasks in the system anyway, and it means + * that we can use a bitmap to indicate which contexts are in use. + * Using a bitmap means that we entirely avoid all of the problems + * that we used to have when the context number overflowed, + * particularly on SMP systems. + * -- paulus. + */ +#define NO_CONTEXT ((unsigned long) -1) +#define LAST_CONTEXT 32767 +#define FIRST_CONTEXT 1 + +/* + * This function defines the mapping from contexts to VSIDs (virtual + * segment IDs). We use a skew on both the context and the high 4 bits + * of the 32-bit virtual address (the "effective segment ID") in order + * to spread out the entries in the MMU hash table. Note, if this + * function is changed then arch/ppc/mm/hashtable.S will have to be + * changed to correspond. + * + * + * CTX_TO_VSID(ctx, va) (((ctx) * (897 * 16) + ((va) >> 28) * 0x111) \ + * & 0xffffff) + */ + +static unsigned long next_mmu_context; +static unsigned long context_map[LAST_CONTEXT / BITS_PER_LONG + 1]; + +unsigned long __init_new_context(void) +{ + unsigned long ctx = next_mmu_context; + + while (test_and_set_bit(ctx, context_map)) { + ctx = find_next_zero_bit(context_map, LAST_CONTEXT+1, ctx); + if (ctx > LAST_CONTEXT) + ctx = 0; + } + next_mmu_context = (ctx + 1) & LAST_CONTEXT; + + return ctx; +} +EXPORT_SYMBOL_GPL(__init_new_context); + +/* + * Set up the context for a new address space. + */ +int init_new_context(struct task_struct *t, struct mm_struct *mm) +{ + mm->context.id = __init_new_context(); + + return 0; +} + +/* + * Free a context ID. Make sure to call this with preempt disabled! + */ +void __destroy_context(unsigned long ctx) +{ + clear_bit(ctx, context_map); +} +EXPORT_SYMBOL_GPL(__destroy_context); + +/* + * We're finished using the context for an address space. + */ +void destroy_context(struct mm_struct *mm) +{ + preempt_disable(); + if (mm->context.id != NO_CONTEXT) { + __destroy_context(mm->context.id); + mm->context.id = NO_CONTEXT; + } + preempt_enable(); +} + +/* + * Initialize the context management stuff. + */ +void __init mmu_context_init(void) +{ + /* Reserve context 0 for kernel use */ + context_map[0] = (1 << FIRST_CONTEXT) - 1; + next_mmu_context = FIRST_CONTEXT; +} diff --git a/arch/powerpc/mm/book3s32/tlb.c b/arch/powerpc/mm/book3s32/tlb.c new file mode 100644 index 000000000..b6c7427da --- /dev/null +++ b/arch/powerpc/mm/book3s32/tlb.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * This file contains the routines for TLB flushing. + * On machines where the MMU uses a hash table to store virtual to + * physical translations, these routines flush entries from the + * hash table also. + * -- paulus + * + * Derived from arch/ppc/mm/init.c: + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) + * and Cort Dougan (PReP) (cort@cs.nmt.edu) + * Copyright (C) 1996 Paul Mackerras + * + * Derived from "arch/i386/mm/init.c" + * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds + */ + +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/highmem.h> +#include <linux/pagemap.h> +#include <linux/export.h> + +#include <asm/tlbflush.h> +#include <asm/tlb.h> + +#include <mm/mmu_decl.h> + +/* + * Called when unmapping pages to flush entries from the TLB/hash table. + */ +void flush_hash_entry(struct mm_struct *mm, pte_t *ptep, unsigned long addr) +{ + unsigned long ptephys; + + if (Hash) { + ptephys = __pa(ptep) & PAGE_MASK; + flush_hash_pages(mm->context.id, addr, ptephys, 1); + } +} +EXPORT_SYMBOL(flush_hash_entry); + +/* + * Called at the end of a mmu_gather operation to make sure the + * TLB flush is completely done. + */ +void tlb_flush(struct mmu_gather *tlb) +{ + if (!Hash) { + /* + * 603 needs to flush the whole TLB here since + * it doesn't use a hash table. + */ + _tlbia(); + } +} + +/* + * TLB flushing: + * + * - flush_tlb_mm(mm) flushes the specified mm context TLB's + * - flush_tlb_page(vma, vmaddr) flushes one page + * - flush_tlb_range(vma, start, end) flushes a range of pages + * - flush_tlb_kernel_range(start, end) flushes kernel pages + * + * since the hardware hash table functions as an extension of the + * tlb as far as the linux tables are concerned, flush it too. + * -- Cort + */ + +static void flush_range(struct mm_struct *mm, unsigned long start, + unsigned long end) +{ + pmd_t *pmd; + unsigned long pmd_end; + int count; + unsigned int ctx = mm->context.id; + + start &= PAGE_MASK; + if (!Hash) { + if (end - start <= PAGE_SIZE) + _tlbie(start); + else + _tlbia(); + return; + } + if (start >= end) + return; + end = (end - 1) | ~PAGE_MASK; + pmd = pmd_off(mm, start); + for (;;) { + pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1; + if (pmd_end > end) + pmd_end = end; + if (!pmd_none(*pmd)) { + count = ((pmd_end - start) >> PAGE_SHIFT) + 1; + flush_hash_pages(ctx, start, pmd_val(*pmd), count); + } + if (pmd_end == end) + break; + start = pmd_end + 1; + ++pmd; + } +} + +/* + * Flush kernel TLB entries in the given range + */ +void flush_tlb_kernel_range(unsigned long start, unsigned long end) +{ + flush_range(&init_mm, start, end); +} +EXPORT_SYMBOL(flush_tlb_kernel_range); + +/* + * Flush all the (user) entries for the address space described by mm. + */ +void flush_tlb_mm(struct mm_struct *mm) +{ + struct vm_area_struct *mp; + + if (!Hash) { + _tlbia(); + return; + } + + /* + * It is safe to go down the mm's list of vmas when called + * from dup_mmap, holding mmap_lock. It would also be safe from + * unmap_region or exit_mmap, but not from vmtruncate on SMP - + * but it seems dup_mmap is the only SMP case which gets here. + */ + for (mp = mm->mmap; mp != NULL; mp = mp->vm_next) + flush_range(mp->vm_mm, mp->vm_start, mp->vm_end); +} +EXPORT_SYMBOL(flush_tlb_mm); + +void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr) +{ + struct mm_struct *mm; + pmd_t *pmd; + + if (!Hash) { + _tlbie(vmaddr); + return; + } + mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm; + pmd = pmd_off(mm, vmaddr); + if (!pmd_none(*pmd)) + flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1); +} +EXPORT_SYMBOL(flush_tlb_page); + +/* + * For each address in the range, find the pte for the address + * and check _PAGE_HASHPTE bit; if it is set, find and destroy + * the corresponding HPTE. + */ +void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) +{ + flush_range(vma->vm_mm, start, end); +} +EXPORT_SYMBOL(flush_tlb_range); + +void __init early_init_mmu(void) +{ +} |