From: David S. Miller Date: Wed, 1 Feb 2006 23:55:21 +0000 (-0800) Subject: [SPARC64]: Access TSB with physical addresses when possible. X-Git-Tag: v2.6.17-rc1~1184^2~206 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=517af33237ecfc3c8a93b335365fa61e741ceca4;p=linux-2.6 [SPARC64]: Access TSB with physical addresses when possible. This way we don't need to lock the TSB into the TLB. The trick is that every TSB load/store is registered into a special instruction patch section. The default uses virtual addresses, and the patch instructions use physical address load/stores. We can't do this on all chips because only cheetah+ and later have the physical variant of the atomic quad load. Signed-off-by: David S. Miller --- diff --git a/arch/sparc64/kernel/dtlb_miss.S b/arch/sparc64/kernel/dtlb_miss.S index d0f1565cb5..2ef6f6e6e7 100644 --- a/arch/sparc64/kernel/dtlb_miss.S +++ b/arch/sparc64/kernel/dtlb_miss.S @@ -4,7 +4,7 @@ srlx %g6, 48, %g5 ! Get context brz,pn %g5, kvmap_dtlb ! Context 0 processing nop ! Delay slot (fill me) - ldda [%g1] ASI_NUCLEUS_QUAD_LDD, %g4 ! Load TSB entry + TSB_LOAD_QUAD(%g1, %g4) ! Load TSB entry nop ! Push branch to next I$ line cmp %g4, %g6 ! Compare TAG diff --git a/arch/sparc64/kernel/itlb_miss.S b/arch/sparc64/kernel/itlb_miss.S index 6b6c8fee04..97facce27a 100644 --- a/arch/sparc64/kernel/itlb_miss.S +++ b/arch/sparc64/kernel/itlb_miss.S @@ -4,7 +4,7 @@ srlx %g6, 48, %g5 ! Get context brz,pn %g5, kvmap_itlb ! Context 0 processing nop ! Delay slot (fill me) - ldda [%g1] ASI_NUCLEUS_QUAD_LDD, %g4 ! Load TSB entry + TSB_LOAD_QUAD(%g1, %g4) ! Load TSB entry cmp %g4, %g6 ! Compare TAG sethi %hi(_PAGE_EXEC), %g4 ! Setup exec check diff --git a/arch/sparc64/kernel/ktlb.S b/arch/sparc64/kernel/ktlb.S index 2b5e71b688..9b415ab6db 100644 --- a/arch/sparc64/kernel/ktlb.S +++ b/arch/sparc64/kernel/ktlb.S @@ -44,14 +44,14 @@ kvmap_itlb_tsb_miss: kvmap_itlb_vmalloc_addr: KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_itlb_longpath) - TSB_LOCK_TAG(%g1, %g2, %g4) + KTSB_LOCK_TAG(%g1, %g2, %g4) /* Load and check PTE. */ ldxa [%g5] ASI_PHYS_USE_EC, %g5 brgez,a,pn %g5, kvmap_itlb_longpath - stx %g0, [%g1] + KTSB_STORE(%g1, %g0) - TSB_WRITE(%g1, %g5, %g6) + KTSB_WRITE(%g1, %g5, %g6) /* fallthrough to TLB load */ @@ -69,9 +69,9 @@ kvmap_itlb_longpath: kvmap_itlb_obp: OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_itlb_longpath) - TSB_LOCK_TAG(%g1, %g2, %g4) + KTSB_LOCK_TAG(%g1, %g2, %g4) - TSB_WRITE(%g1, %g5, %g6) + KTSB_WRITE(%g1, %g5, %g6) ba,pt %xcc, kvmap_itlb_load nop @@ -79,9 +79,9 @@ kvmap_itlb_obp: kvmap_dtlb_obp: OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_dtlb_longpath) - TSB_LOCK_TAG(%g1, %g2, %g4) + KTSB_LOCK_TAG(%g1, %g2, %g4) - TSB_WRITE(%g1, %g5, %g6) + KTSB_WRITE(%g1, %g5, %g6) ba,pt %xcc, kvmap_dtlb_load nop @@ -114,14 +114,14 @@ kvmap_linear_patch: kvmap_dtlb_vmalloc_addr: KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_dtlb_longpath) - TSB_LOCK_TAG(%g1, %g2, %g4) + KTSB_LOCK_TAG(%g1, %g2, %g4) /* Load and check PTE. */ ldxa [%g5] ASI_PHYS_USE_EC, %g5 brgez,a,pn %g5, kvmap_dtlb_longpath - stx %g0, [%g1] + KTSB_STORE(%g1, %g0) - TSB_WRITE(%g1, %g5, %g6) + KTSB_WRITE(%g1, %g5, %g6) /* fallthrough to TLB load */ diff --git a/arch/sparc64/kernel/tsb.S b/arch/sparc64/kernel/tsb.S index e1dd37f5e5..ff6a79beb9 100644 --- a/arch/sparc64/kernel/tsb.S +++ b/arch/sparc64/kernel/tsb.S @@ -53,7 +53,7 @@ tsb_reload: /* Load and check PTE. */ ldxa [%g5] ASI_PHYS_USE_EC, %g5 brgez,a,pn %g5, tsb_do_fault - stx %g0, [%g1] + TSB_STORE(%g1, %g0) /* If it is larger than the base page size, don't * bother putting it into the TSB. @@ -64,7 +64,7 @@ tsb_reload: and %g2, %g4, %g2 cmp %g2, %g7 bne,a,pn %xcc, tsb_tlb_reload - stx %g0, [%g1] + TSB_STORE(%g1, %g0) TSB_WRITE(%g1, %g5, %g6) @@ -131,13 +131,13 @@ winfix_trampoline: /* Insert an entry into the TSB. * - * %o0: TSB entry pointer + * %o0: TSB entry pointer (virt or phys address) * %o1: tag * %o2: pte */ .align 32 - .globl tsb_insert -tsb_insert: + .globl __tsb_insert +__tsb_insert: rdpr %pstate, %o5 wrpr %o5, PSTATE_IE, %pstate TSB_LOCK_TAG(%o0, %g2, %g3) @@ -146,6 +146,31 @@ tsb_insert: retl nop + /* Flush the given TSB entry if it has the matching + * tag. + * + * %o0: TSB entry pointer (virt or phys address) + * %o1: tag + */ + .align 32 + .globl tsb_flush +tsb_flush: + sethi %hi(TSB_TAG_LOCK_HIGH), %g2 +1: TSB_LOAD_TAG(%o0, %g1) + srlx %g1, 32, %o3 + andcc %o3, %g2, %g0 + bne,pn %icc, 1b + membar #LoadLoad + cmp %g1, %o1 + bne,pt %xcc, 2f + clr %o3 + TSB_CAS_TAG(%o0, %g1, %o3) + cmp %g1, %o3 + bne,pn %xcc, 1b + nop +2: retl + TSB_MEMBAR + /* Reload MMU related context switch state at * schedule() time. * diff --git a/arch/sparc64/kernel/vmlinux.lds.S b/arch/sparc64/kernel/vmlinux.lds.S index 467d13a0d5..71b943f1c9 100644 --- a/arch/sparc64/kernel/vmlinux.lds.S +++ b/arch/sparc64/kernel/vmlinux.lds.S @@ -70,6 +70,10 @@ SECTIONS .con_initcall.init : { *(.con_initcall.init) } __con_initcall_end = .; SECURITY_INIT + . = ALIGN(4); + __tsb_phys_patch = .; + .tsb_phys_patch : { *(.tsb_phys_patch) } + __tsb_phys_patch_end = .; . = ALIGN(8192); __initramfs_start = .; .init.ramfs : { *(.init.ramfs) } diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c index 2c21d85de7..4893f3e2c3 100644 --- a/arch/sparc64/mm/init.c +++ b/arch/sparc64/mm/init.c @@ -39,6 +39,7 @@ #include #include #include +#include extern void device_scan(void); @@ -244,6 +245,16 @@ static __inline__ void clear_dcache_dirty_cpu(struct page *page, unsigned long c : "g1", "g7"); } +static inline void tsb_insert(struct tsb *ent, unsigned long tag, unsigned long pte) +{ + unsigned long tsb_addr = (unsigned long) ent; + + if (tlb_type == cheetah_plus) + tsb_addr = __pa(tsb_addr); + + __tsb_insert(tsb_addr, tag, pte); +} + void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t pte) { struct mm_struct *mm; @@ -1040,6 +1051,24 @@ unsigned long __init find_ecache_flush_span(unsigned long size) return ~0UL; } +static void __init tsb_phys_patch(void) +{ + struct tsb_phys_patch_entry *p; + + p = &__tsb_phys_patch; + while (p < &__tsb_phys_patch_end) { + unsigned long addr = p->addr; + + *(unsigned int *) addr = p->insn; + wmb(); + __asm__ __volatile__("flush %0" + : /* no outputs */ + : "r" (addr)); + + p++; + } +} + /* paging_init() sets up the page tables */ extern void cheetah_ecache_flush_init(void); @@ -1052,6 +1081,9 @@ void __init paging_init(void) unsigned long end_pfn, pages_avail, shift; unsigned long real_end, i; + if (tlb_type == cheetah_plus) + tsb_phys_patch(); + /* Find available physical memory... */ read_obp_memory("available", &pavail[0], &pavail_ents); diff --git a/arch/sparc64/mm/tsb.c b/arch/sparc64/mm/tsb.c index 1c4e5c2dfc..787533f010 100644 --- a/arch/sparc64/mm/tsb.c +++ b/arch/sparc64/mm/tsb.c @@ -20,12 +20,9 @@ static inline unsigned long tsb_hash(unsigned long vaddr, unsigned long nentries return vaddr & (nentries - 1); } -static inline int tag_compare(struct tsb *entry, unsigned long vaddr, unsigned long context) +static inline int tag_compare(unsigned long tag, unsigned long vaddr, unsigned long context) { - if (context == ~0UL) - return 1; - - return (entry->tag == ((vaddr >> 22) | (context << 48))); + return (tag == ((vaddr >> 22) | (context << 48))); } /* TSB flushes need only occur on the processor initiating the address @@ -41,7 +38,7 @@ void flush_tsb_kernel_range(unsigned long start, unsigned long end) unsigned long hash = tsb_hash(v, KERNEL_TSB_NENTRIES); struct tsb *ent = &swapper_tsb[hash]; - if (tag_compare(ent, v, 0)) { + if (tag_compare(ent->tag, v, 0)) { ent->tag = 0UL; membar_storeload_storestore(); } @@ -52,24 +49,31 @@ void flush_tsb_user(struct mmu_gather *mp) { struct mm_struct *mm = mp->mm; struct tsb *tsb = mm->context.tsb; - unsigned long ctx = ~0UL; unsigned long nentries = mm->context.tsb_nentries; + unsigned long ctx, base; int i; - if (CTX_VALID(mm->context)) - ctx = CTX_HWBITS(mm->context); + if (unlikely(!CTX_VALID(mm->context))) + return; + + ctx = CTX_HWBITS(mm->context); + if (tlb_type == cheetah_plus) + base = __pa(tsb); + else + base = (unsigned long) tsb; + for (i = 0; i < mp->tlb_nr; i++) { unsigned long v = mp->vaddrs[i]; - struct tsb *ent; + unsigned long tag, ent, hash; v &= ~0x1UL; - ent = &tsb[tsb_hash(v, nentries)]; - if (tag_compare(ent, v, ctx)) { - ent->tag = 0UL; - membar_storeload_storestore(); - } + hash = tsb_hash(v, nentries); + ent = base + (hash * sizeof(struct tsb)); + tag = (v >> 22UL) | (ctx << 48UL); + + tsb_flush(ent, tag); } } @@ -84,6 +88,7 @@ static void setup_tsb_params(struct mm_struct *mm, unsigned long tsb_bytes) tte = (_PAGE_VALID | _PAGE_L | _PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_W); tsb_paddr = __pa(mm->context.tsb); + BUG_ON(tsb_paddr & (tsb_bytes - 1UL)); /* Use the smallest page size that can map the whole TSB * in one TLB entry. @@ -144,13 +149,23 @@ static void setup_tsb_params(struct mm_struct *mm, unsigned long tsb_bytes) BUG(); }; - tsb_reg |= base; - tsb_reg |= (tsb_paddr & (page_sz - 1UL)); - tte |= (tsb_paddr & ~(page_sz - 1UL)); + if (tlb_type == cheetah_plus) { + /* Physical mapping, no locked TLB entry for TSB. */ + tsb_reg |= tsb_paddr; + + mm->context.tsb_reg_val = tsb_reg; + mm->context.tsb_map_vaddr = 0; + mm->context.tsb_map_pte = 0; + } else { + tsb_reg |= base; + tsb_reg |= (tsb_paddr & (page_sz - 1UL)); + tte |= (tsb_paddr & ~(page_sz - 1UL)); + + mm->context.tsb_reg_val = tsb_reg; + mm->context.tsb_map_vaddr = base; + mm->context.tsb_map_pte = tte; + } - mm->context.tsb_reg_val = tsb_reg; - mm->context.tsb_map_vaddr = base; - mm->context.tsb_map_pte = tte; } /* The page tables are locked against modifications while this @@ -168,13 +183,21 @@ static void copy_tsb(struct tsb *old_tsb, unsigned long old_size, for (i = 0; i < old_nentries; i++) { register unsigned long tag asm("o4"); register unsigned long pte asm("o5"); - unsigned long v; - unsigned int hash; - - __asm__ __volatile__( - "ldda [%2] %3, %0" - : "=r" (tag), "=r" (pte) - : "r" (&old_tsb[i]), "i" (ASI_NUCLEUS_QUAD_LDD)); + unsigned long v, hash; + + if (tlb_type == cheetah_plus) { + __asm__ __volatile__( + "ldda [%2] %3, %0" + : "=r" (tag), "=r" (pte) + : "r" (__pa(&old_tsb[i])), + "i" (ASI_QUAD_LDD_PHYS)); + } else { + __asm__ __volatile__( + "ldda [%2] %3, %0" + : "=r" (tag), "=r" (pte) + : "r" (&old_tsb[i]), + "i" (ASI_NUCLEUS_QUAD_LDD)); + } if (!tag || (tag & (1UL << TSB_TAG_LOCK_BIT))) continue; @@ -198,8 +221,20 @@ static void copy_tsb(struct tsb *old_tsb, unsigned long old_size, v |= (i & (512UL - 1UL)) << 13UL; hash = tsb_hash(v, new_nentries); - new_tsb[hash].tag = tag; - new_tsb[hash].pte = pte; + if (tlb_type == cheetah_plus) { + __asm__ __volatile__( + "stxa %0, [%1] %2\n\t" + "stxa %3, [%4] %2" + : /* no outputs */ + : "r" (tag), + "r" (__pa(&new_tsb[hash].tag)), + "i" (ASI_PHYS_USE_EC), + "r" (pte), + "r" (__pa(&new_tsb[hash].pte))); + } else { + new_tsb[hash].tag = tag; + new_tsb[hash].pte = pte; + } } } diff --git a/include/asm-sparc64/mmu.h b/include/asm-sparc64/mmu.h index 18f98edfbc..55e622711b 100644 --- a/include/asm-sparc64/mmu.h +++ b/include/asm-sparc64/mmu.h @@ -97,7 +97,8 @@ struct tsb { unsigned long pte; } __attribute__((aligned(TSB_ENTRY_ALIGNMENT))); -extern void tsb_insert(struct tsb *ent, unsigned long tag, unsigned long pte); +extern void __tsb_insert(unsigned long ent, unsigned long tag, unsigned long pte); +extern void tsb_flush(unsigned long ent, unsigned long tag); typedef struct { unsigned long sparc64_ctx_val; diff --git a/include/asm-sparc64/tsb.h b/include/asm-sparc64/tsb.h index f384565212..44709cde56 100644 --- a/include/asm-sparc64/tsb.h +++ b/include/asm-sparc64/tsb.h @@ -44,7 +44,89 @@ #define TSB_MEMBAR membar #StoreStore +/* Some cpus support physical address quad loads. We want to use + * those if possible so we don't need to hard-lock the TSB mapping + * into the TLB. We encode some instruction patching in order to + * support this. + * + * The kernel TSB is locked into the TLB by virtue of being in the + * kernel image, so we don't play these games for swapper_tsb access. + */ +#ifndef __ASSEMBLY__ +struct tsb_phys_patch_entry { + unsigned int addr; + unsigned int insn; +}; +extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end; +#endif +#define TSB_LOAD_QUAD(TSB, REG) \ +661: ldda [TSB] ASI_NUCLEUS_QUAD_LDD, REG; \ + .section .tsb_phys_patch, "ax"; \ + .word 661b; \ + ldda [TSB] ASI_QUAD_LDD_PHYS, REG; \ + .previous + +#define TSB_LOAD_TAG_HIGH(TSB, REG) \ +661: lduwa [TSB] ASI_N, REG; \ + .section .tsb_phys_patch, "ax"; \ + .word 661b; \ + lduwa [TSB] ASI_PHYS_USE_EC, REG; \ + .previous + +#define TSB_LOAD_TAG(TSB, REG) \ +661: ldxa [TSB] ASI_N, REG; \ + .section .tsb_phys_patch, "ax"; \ + .word 661b; \ + ldxa [TSB] ASI_PHYS_USE_EC, REG; \ + .previous + +#define TSB_CAS_TAG_HIGH(TSB, REG1, REG2) \ +661: casa [TSB] ASI_N, REG1, REG2; \ + .section .tsb_phys_patch, "ax"; \ + .word 661b; \ + casa [TSB] ASI_PHYS_USE_EC, REG1, REG2; \ + .previous + +#define TSB_CAS_TAG(TSB, REG1, REG2) \ +661: casxa [TSB] ASI_N, REG1, REG2; \ + .section .tsb_phys_patch, "ax"; \ + .word 661b; \ + casxa [TSB] ASI_PHYS_USE_EC, REG1, REG2; \ + .previous + +#define TSB_STORE(ADDR, VAL) \ +661: stxa VAL, [ADDR] ASI_N; \ + .section .tsb_phys_patch, "ax"; \ + .word 661b; \ + stxa VAL, [ADDR] ASI_PHYS_USE_EC; \ + .previous + #define TSB_LOCK_TAG(TSB, REG1, REG2) \ +99: TSB_LOAD_TAG_HIGH(TSB, REG1); \ + sethi %hi(TSB_TAG_LOCK_HIGH), REG2;\ + andcc REG1, REG2, %g0; \ + bne,pn %icc, 99b; \ + nop; \ + TSB_CAS_TAG_HIGH(TSB, REG1, REG2); \ + cmp REG1, REG2; \ + bne,pn %icc, 99b; \ + nop; \ + TSB_MEMBAR + +#define TSB_WRITE(TSB, TTE, TAG) \ + add TSB, 0x8, TSB; \ + TSB_STORE(TSB, TTE); \ + sub TSB, 0x8, TSB; \ + TSB_MEMBAR; \ + TSB_STORE(TSB, TAG); + +#define KTSB_LOAD_QUAD(TSB, REG) \ + ldda [TSB] ASI_NUCLEUS_QUAD_LDD, REG; + +#define KTSB_STORE(ADDR, VAL) \ + stxa VAL, [ADDR] ASI_N; + +#define KTSB_LOCK_TAG(TSB, REG1, REG2) \ 99: lduwa [TSB] ASI_N, REG1; \ sethi %hi(TSB_TAG_LOCK_HIGH), REG2;\ andcc REG1, REG2, %g0; \ @@ -56,10 +138,12 @@ nop; \ TSB_MEMBAR -#define TSB_WRITE(TSB, TTE, TAG) \ - stx TTE, [TSB + 0x08]; \ - TSB_MEMBAR; \ - stx TAG, [TSB + 0x00]; +#define KTSB_WRITE(TSB, TTE, TAG) \ + add TSB, 0x8, TSB; \ + stxa TTE, [TSB] ASI_N; \ + sub TSB, 0x8, TSB; \ + TSB_MEMBAR; \ + stxa TAG, [TSB] ASI_N; /* Do a kernel page table walk. Leaves physical PTE pointer in * REG1. Jumps to FAIL_LABEL on early page table walk termination. @@ -157,7 +241,7 @@ and REG2, (KERNEL_TSB_NENTRIES - 1), REG2; \ sllx REG2, 4, REG2; \ add REG1, REG2, REG2; \ - ldda [REG2] ASI_NUCLEUS_QUAD_LDD, REG3; \ + KTSB_LOAD_QUAD(REG2, REG3); \ cmp REG3, TAG; \ be,a,pt %xcc, OK_LABEL; \ mov REG4, REG1;