From 3d8bfdd0307223de678962f1c1907a7cec549136 Mon Sep 17 00:00:00 2001 From: David Daney Date: Tue, 21 Dec 2010 14:19:11 -0800 Subject: MIPS: Use C0_KScratch (if present) to hold PGD pointer. Decide at runtime to use either Context or KScratch to hold the PGD pointer. Signed-off-by: David Daney To: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/1876/ Signed-off-by: Ralf Baechle --- arch/mips/include/asm/mmu_context.h | 8 +-- arch/mips/kernel/traps.c | 2 +- arch/mips/mm/tlbex.c | 116 ++++++++++++++++++++++++++++++++---- 3 files changed, 108 insertions(+), 18 deletions(-) diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h index d9592733a7ba..73c0d45798de 100644 --- a/arch/mips/include/asm/mmu_context.h +++ b/arch/mips/include/asm/mmu_context.h @@ -29,13 +29,7 @@ #define TLBMISS_HANDLER_SETUP_PGD(pgd) \ tlbmiss_handler_setup_pgd((unsigned long)(pgd)) -static inline void tlbmiss_handler_setup_pgd(unsigned long pgd) -{ - /* Check for swapper_pg_dir and convert to physical address. */ - if ((pgd & CKSEG3) == CKSEG0) - pgd = CPHYSADDR(pgd); - write_c0_context(pgd << 11); -} +extern void tlbmiss_handler_setup_pgd(unsigned long pgd); #define TLBMISS_HANDLER_SETUP() \ do { \ diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index e97104302541..71350f7f2d88 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -1592,7 +1592,6 @@ void __cpuinit per_cpu_trap_init(void) #endif /* CONFIG_MIPS_MT_SMTC */ cpu_data[cpu].asid_cache = ASID_FIRST_VERSION; - TLBMISS_HANDLER_SETUP(); atomic_inc(&init_mm.mm_count); current->active_mm = &init_mm; @@ -1614,6 +1613,7 @@ void __cpuinit per_cpu_trap_init(void) write_c0_wired(0); } #endif /* CONFIG_MIPS_MT_SMTC */ + TLBMISS_HANDLER_SETUP(); } /* Install CPU exception handler */ diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index 93816f3bca67..0bb4c3b89c78 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -26,8 +26,10 @@ #include #include #include +#include -#include +#include +#include #include #include @@ -173,11 +175,38 @@ static struct uasm_reloc relocs[128] __cpuinitdata; static int check_for_high_segbits __cpuinitdata; #endif -#ifndef CONFIG_MIPS_PGD_C0_CONTEXT +#ifdef CONFIG_MIPS_PGD_C0_CONTEXT + +static unsigned int kscratch_used_mask __cpuinitdata; + +static int __cpuinit allocate_kscratch(void) +{ + int r; + unsigned int a = cpu_data[0].kscratch_mask & ~kscratch_used_mask; + + r = ffs(a); + + if (r == 0) + return -1; + + r--; /* make it zero based */ + + kscratch_used_mask |= (1 << r); + + return r; +} + +static int pgd_reg __cpuinitdata; + +#else /* !CONFIG_MIPS_PGD_C0_CONTEXT*/ /* * CONFIG_MIPS_PGD_C0_CONTEXT implies 64 bit and lack of pgd_current, * we cannot do r3000 under these circumstances. + * + * Declare pgd_current here instead of including mmu_context.h to avoid type + * conflicts for tlbmiss_handler_setup_pgd */ +extern unsigned long pgd_current[]; /* * The R3000 TLB handler is simple. @@ -573,13 +602,22 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */ #ifdef CONFIG_MIPS_PGD_C0_CONTEXT - /* - * &pgd << 11 stored in CONTEXT [23..63]. - */ - UASM_i_MFC0(p, ptr, C0_CONTEXT); - uasm_i_dins(p, ptr, 0, 0, 23); /* Clear lower 23 bits of context. */ - uasm_i_ori(p, ptr, ptr, 0x540); /* 1 0 1 0 1 << 6 xkphys cached */ - uasm_i_drotr(p, ptr, ptr, 11); + if (pgd_reg != -1) { + /* pgd is in pgd_reg */ + UASM_i_MFC0(p, ptr, 31, pgd_reg); + } else { + /* + * &pgd << 11 stored in CONTEXT [23..63]. + */ + UASM_i_MFC0(p, ptr, C0_CONTEXT); + + /* Clear lower 23 bits of context. */ + uasm_i_dins(p, ptr, 0, 0, 23); + + /* 1 0 1 0 1 << 6 xkphys cached */ + uasm_i_ori(p, ptr, ptr, 0x540); + uasm_i_drotr(p, ptr, ptr, 11); + } #elif defined(CONFIG_SMP) # ifdef CONFIG_MIPS_MT_SMTC /* @@ -1014,6 +1052,55 @@ static void __cpuinit build_r4000_tlb_refill_handler(void) u32 handle_tlbl[FASTPATH_SIZE] __cacheline_aligned; u32 handle_tlbs[FASTPATH_SIZE] __cacheline_aligned; u32 handle_tlbm[FASTPATH_SIZE] __cacheline_aligned; +#ifdef CONFIG_MIPS_PGD_C0_CONTEXT +u32 tlbmiss_handler_setup_pgd[16] __cacheline_aligned; + +static void __cpuinit build_r4000_setup_pgd(void) +{ + const int a0 = 4; + const int a1 = 5; + u32 *p = tlbmiss_handler_setup_pgd; + struct uasm_label *l = labels; + struct uasm_reloc *r = relocs; + + memset(tlbmiss_handler_setup_pgd, 0, sizeof(tlbmiss_handler_setup_pgd)); + memset(labels, 0, sizeof(labels)); + memset(relocs, 0, sizeof(relocs)); + + pgd_reg = allocate_kscratch(); + + if (pgd_reg == -1) { + /* PGD << 11 in c0_Context */ + /* + * If it is a ckseg0 address, convert to a physical + * address. Shifting right by 29 and adding 4 will + * result in zero for these addresses. + * + */ + UASM_i_SRA(&p, a1, a0, 29); + UASM_i_ADDIU(&p, a1, a1, 4); + uasm_il_bnez(&p, &r, a1, label_tlbl_goaround1); + uasm_i_nop(&p); + uasm_i_dinsm(&p, a0, 0, 29, 64 - 29); + uasm_l_tlbl_goaround1(&l, p); + UASM_i_SLL(&p, a0, a0, 11); + uasm_i_jr(&p, 31); + UASM_i_MTC0(&p, a0, C0_CONTEXT); + } else { + /* PGD in c0_KScratch */ + uasm_i_jr(&p, 31); + UASM_i_MTC0(&p, a0, 31, pgd_reg); + } + if (p - tlbmiss_handler_setup_pgd > ARRAY_SIZE(tlbmiss_handler_setup_pgd)) + panic("tlbmiss_handler_setup_pgd space exceeded"); + uasm_resolve_relocs(relocs, labels); + pr_debug("Wrote tlbmiss_handler_setup_pgd (%u instructions).\n", + (unsigned int)(p - tlbmiss_handler_setup_pgd)); + + dump_handler(tlbmiss_handler_setup_pgd, + ARRAY_SIZE(tlbmiss_handler_setup_pgd)); +} +#endif static void __cpuinit iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr) @@ -1161,6 +1248,8 @@ build_pte_modifiable(u32 **p, struct uasm_reloc **r, } #ifndef CONFIG_MIPS_PGD_C0_CONTEXT + + /* * R3000 style TLB load/store/modify handlers. */ @@ -1623,13 +1712,16 @@ void __cpuinit build_tlb_refill_handler(void) break; default: - build_r4000_tlb_refill_handler(); if (!run_once) { +#ifdef CONFIG_MIPS_PGD_C0_CONTEXT + build_r4000_setup_pgd(); +#endif build_r4000_tlb_load_handler(); build_r4000_tlb_store_handler(); build_r4000_tlb_modify_handler(); run_once++; } + build_r4000_tlb_refill_handler(); } } @@ -1641,4 +1733,8 @@ void __cpuinit flush_tlb_handlers(void) (unsigned long)handle_tlbs + sizeof(handle_tlbs)); local_flush_icache_range((unsigned long)handle_tlbm, (unsigned long)handle_tlbm + sizeof(handle_tlbm)); +#ifdef CONFIG_MIPS_PGD_C0_CONTEXT + local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd, + (unsigned long)tlbmiss_handler_setup_pgd + sizeof(handle_tlbm)); +#endif } -- cgit v1.2.3