From 89460ce8912200429c8ed141a01eabd226683614 Mon Sep 17 00:00:00 2001 From: Jayachandran C Date: Tue, 18 Jun 2013 11:45:15 +0000 Subject: [PATCH] MIPS: mm: Use scratch for PGD when !CONFIG_MIPS_PGD_C0_CONTEXT Allow usage of scratch register for current pgd even when MIPS_PGD_C0_CONTEXT is not configured. MIPS_PGD_C0_CONTEXT is set for 64r2 platforms to indicate availability of Xcontext for saving cpuid, thus freeing Context to be used for saving PGD. This option was also tied to using a scratch register for storing PGD. This commit will allow usage of scratch register to store the current pgd if one can be allocated for the platform, even when MIPS_PGD_C0_CONTEXT is not set. The cpuid will be kept in the CP0 Context register in this case. The code to store the current pgd for the TLB miss handler is now generated in all cases. When scratch register is available, the PGD is also stored in the scratch register. Signed-off-by: Jayachandran C Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5491/ Signed-off-by: Ralf Baechle --- arch/mips/include/asm/mmu_context.h | 7 +- arch/mips/mm/tlbex.c | 142 ++++++++++++++++++---------- 2 files changed, 92 insertions(+), 57 deletions(-) diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h index 820116067c10..3e20577686b7 100644 --- a/arch/mips/include/asm/mmu_context.h +++ b/arch/mips/include/asm/mmu_context.h @@ -24,8 +24,6 @@ #endif /* SMTC */ #include -#ifdef CONFIG_MIPS_PGD_C0_CONTEXT - #define TLBMISS_HANDLER_SETUP_PGD(pgd) \ do { \ void (*tlbmiss_handler_setup_pgd)(unsigned long); \ @@ -36,6 +34,8 @@ do { \ tlbmiss_handler_setup_pgd((unsigned long)(pgd)); \ } while (0) + +#ifdef CONFIG_MIPS_PGD_C0_CONTEXT #define TLBMISS_HANDLER_SETUP() \ do { \ TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir); \ @@ -51,9 +51,6 @@ do { \ */ extern unsigned long pgd_current[]; -#define TLBMISS_HANDLER_SETUP_PGD(pgd) \ - pgd_current[smp_processor_id()] = (unsigned long)(pgd) - #ifdef CONFIG_32BIT #define TLBMISS_HANDLER_SETUP() \ write_c0_context((unsigned long) smp_processor_id() << 25); \ diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index 9b988c050fdd..b23c744e06c3 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -825,11 +825,11 @@ 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 if (pgd_reg != -1) { /* pgd is in pgd_reg */ UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg); } else { +#ifdef CONFIG_MIPS_PGD_C0_CONTEXT /* * &pgd << 11 stored in CONTEXT [23..63]. */ @@ -841,30 +841,30 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, /* 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 - /* - * SMTC uses TCBind value as "CPU" index - */ - uasm_i_mfc0(p, ptr, C0_TCBIND); - uasm_i_dsrl_safe(p, ptr, ptr, 19); +# ifdef CONFIG_MIPS_MT_SMTC + /* + * SMTC uses TCBind value as "CPU" index + */ + uasm_i_mfc0(p, ptr, C0_TCBIND); + uasm_i_dsrl_safe(p, ptr, ptr, 19); # else - /* - * 64 bit SMP running in XKPHYS has smp_processor_id() << 3 - * stored in CONTEXT. - */ - uasm_i_dmfc0(p, ptr, C0_CONTEXT); - uasm_i_dsrl_safe(p, ptr, ptr, 23); + /* + * 64 bit SMP running in XKPHYS has smp_processor_id() << 3 + * stored in CONTEXT. + */ + uasm_i_dmfc0(p, ptr, C0_CONTEXT); + uasm_i_dsrl_safe(p, ptr, ptr, 23); # endif - UASM_i_LA_mostly(p, tmp, pgdc); - uasm_i_daddu(p, ptr, ptr, tmp); - uasm_i_dmfc0(p, tmp, C0_BADVADDR); - uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr); + UASM_i_LA_mostly(p, tmp, pgdc); + uasm_i_daddu(p, ptr, ptr, tmp); + uasm_i_dmfc0(p, tmp, C0_BADVADDR); + uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr); #else - UASM_i_LA_mostly(p, ptr, pgdc); - uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr); + UASM_i_LA_mostly(p, ptr, pgdc); + uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr); #endif + } uasm_l_vmalloc_done(l, *p); @@ -959,31 +959,37 @@ build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, static void __cpuinit __maybe_unused build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr) { - long pgdc = (long)pgd_current; + if (pgd_reg != -1) { + /* pgd is in pgd_reg */ + uasm_i_mfc0(p, ptr, c0_kscratch(), pgd_reg); + uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */ + } else { + long pgdc = (long)pgd_current; - /* 32 bit SMP has smp_processor_id() stored in CONTEXT. */ + /* 32 bit SMP has smp_processor_id() stored in CONTEXT. */ #ifdef CONFIG_SMP -#ifdef CONFIG_MIPS_MT_SMTC - /* - * SMTC uses TCBind value as "CPU" index - */ - uasm_i_mfc0(p, ptr, C0_TCBIND); - UASM_i_LA_mostly(p, tmp, pgdc); - uasm_i_srl(p, ptr, ptr, 19); -#else - /* - * smp_processor_id() << 3 is stored in CONTEXT. - */ - uasm_i_mfc0(p, ptr, C0_CONTEXT); - UASM_i_LA_mostly(p, tmp, pgdc); - uasm_i_srl(p, ptr, ptr, 23); -#endif - uasm_i_addu(p, ptr, tmp, ptr); +# ifdef CONFIG_MIPS_MT_SMTC + /* + * SMTC uses TCBind value as "CPU" index + */ + uasm_i_mfc0(p, ptr, C0_TCBIND); + UASM_i_LA_mostly(p, tmp, pgdc); + uasm_i_srl(p, ptr, ptr, 19); +# else + /* + * smp_processor_id() << 3 is stored in CONTEXT. + */ + uasm_i_mfc0(p, ptr, C0_CONTEXT); + UASM_i_LA_mostly(p, tmp, pgdc); + uasm_i_srl(p, ptr, ptr, 23); +# endif + uasm_i_addu(p, ptr, tmp, ptr); #else - UASM_i_LA_mostly(p, ptr, pgdc); + UASM_i_LA_mostly(p, ptr, pgdc); #endif - uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */ - uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr); + uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */ + uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr); + } uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */ uasm_i_sll(p, tmp, tmp, PGD_T_LOG2); uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */ @@ -1464,16 +1470,17 @@ 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_array[16] __cacheline_aligned; -static void __cpuinit build_r4000_setup_pgd(void) +static void __cpuinit build_setup_pgd(void) { const int a0 = 4; - const int a1 = 5; + const int __maybe_unused a1 = 5; + const int __maybe_unused a2 = 6; u32 *p = tlbmiss_handler_setup_pgd_array; - struct uasm_label *l = labels; - struct uasm_reloc *r = relocs; +#ifndef CONFIG_MIPS_PGD_C0_CONTEXT + long pgdc = (long)pgd_current; +#endif memset(tlbmiss_handler_setup_pgd_array, 0, sizeof(tlbmiss_handler_setup_pgd_array)); memset(labels, 0, sizeof(labels)); @@ -1481,7 +1488,11 @@ static void __cpuinit build_r4000_setup_pgd(void) pgd_reg = allocate_kscratch(); +#ifdef CONFIG_MIPS_PGD_C0_CONTEXT if (pgd_reg == -1) { + struct uasm_label *l = labels; + struct uasm_reloc *r = relocs; + /* PGD << 11 in c0_Context */ /* * If it is a ckseg0 address, convert to a physical @@ -1503,6 +1514,37 @@ static void __cpuinit build_r4000_setup_pgd(void) uasm_i_jr(&p, 31); UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg); } +#else + /* Save PGD to pgd_current[smp_processor_id()] */ +#if defined(CONFIG_SMP) +# ifdef CONFIG_MIPS_MT_SMTC + /* + * SMTC uses TCBind value as "CPU" index + */ + uasm_i_mfc0(&p, a1, C0_TCBIND); + UASM_i_SRL_SAFE(&p, a1, a1, 19); +# else + /* + * smp_processor_id() is in CONTEXT + */ + UASM_i_MFC0(&p, a1, C0_CONTEXT); + UASM_i_SRL_SAFE(&p, a1, a1, 23); +# endif + UASM_i_LA_mostly(&p, a2, pgdc); + UASM_i_ADDU(&p, a2, a2, a1); + UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2); +#else + UASM_i_LA_mostly(&p, a2, pgdc); + UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2); +#endif /* SMP */ + uasm_i_jr(&p, 31); + + /* if pgd_reg is allocated, save PGD also to scratch register */ + if (pgd_reg != -1) + UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg); + else + uasm_i_nop(&p); +#endif if (p - tlbmiss_handler_setup_pgd_array > ARRAY_SIZE(tlbmiss_handler_setup_pgd_array)) panic("tlbmiss_handler_setup_pgd_array space exceeded"); uasm_resolve_relocs(relocs, labels); @@ -1513,7 +1555,6 @@ static void __cpuinit build_r4000_setup_pgd(void) tlbmiss_handler_setup_pgd_array, ARRAY_SIZE(tlbmiss_handler_setup_pgd_array)); } -#endif static void __cpuinit iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr) @@ -2195,6 +2236,7 @@ void __cpuinit build_tlb_refill_handler(void) if (!run_once) { if (!cpu_has_local_ebase) build_r3000_tlb_refill_handler(); + build_setup_pgd(); build_r3000_tlb_load_handler(); build_r3000_tlb_store_handler(); build_r3000_tlb_modify_handler(); @@ -2217,9 +2259,7 @@ void __cpuinit build_tlb_refill_handler(void) default: if (!run_once) { scratch_reg = allocate_kscratch(); -#ifdef CONFIG_MIPS_PGD_C0_CONTEXT - build_r4000_setup_pgd(); -#endif + build_setup_pgd(); build_r4000_tlb_load_handler(); build_r4000_tlb_store_handler(); build_r4000_tlb_modify_handler(); @@ -2240,8 +2280,6 @@ 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_array, (unsigned long)tlbmiss_handler_setup_pgd_array + sizeof(handle_tlbm)); -#endif } -- 2.39.5