From 75b5b5e0a262790fa11043fe45700499c7e3d818 Mon Sep 17 00:00:00 2001 From: Leonid Yegoshin Date: Thu, 14 Nov 2013 16:12:31 +0000 Subject: [PATCH] MIPS: Add support for FTLBs The Fixed Page Size TLB (FTLB) is a set-associative dual entry TLB. Its purpose is to reduce the number of TLB misses by increasing the effective TLB size and keep the implementation complexity to minimum levels. A supported core can have both VTLB and FTLB. Reviewed-by: James Hogan Reviewed-by: Paul Burton Signed-off-by: Leonid Yegoshin Signed-off-by: Markos Chandras Signed-off-by: John Crispin Patchwork: http://patchwork.linux-mips.org/patch/6139/ --- arch/mips/include/asm/cpu-info.h | 3 ++ arch/mips/include/asm/mipsregs.h | 2 + arch/mips/include/asm/page.h | 25 +++++++++++++ arch/mips/kernel/cpu-probe.c | 79 ++++++++++++++++++++++++++++++++++++---- arch/mips/kernel/genex.S | 1 + arch/mips/kernel/traps.c | 30 +++++++++++++++ arch/mips/mm/tlb-r4k.c | 29 +++++++++++---- 7 files changed, 155 insertions(+), 14 deletions(-) diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h index 21c8e29..8f7adf0 100644 --- a/arch/mips/include/asm/cpu-info.h +++ b/arch/mips/include/asm/cpu-info.h @@ -52,6 +52,9 @@ struct cpuinfo_mips { unsigned int cputype; int isa_level; int tlbsize; + int tlbsizevtlb; + int tlbsizeftlbsets; + int tlbsizeftlbways; struct cache_desc icache; /* Primary I-cache */ struct cache_desc dcache; /* Primary D or combined I/D cache */ struct cache_desc scache; /* Secondary cache */ diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h index d9910a1..cb57e07 100644 --- a/arch/mips/include/asm/mipsregs.h +++ b/arch/mips/include/asm/mipsregs.h @@ -645,6 +645,8 @@ #define MIPS_CONF5_K (_ULCAST_(1) << 30) #define MIPS_CONF6_SYND (_ULCAST_(1) << 13) +/* proAptiv FTLB on/off bit */ +#define MIPS_CONF6_FTLBEN (_ULCAST_(1) << 15) #define MIPS_CONF7_WII (_ULCAST_(1) << 31) diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h index f6be474..5e08bcc 100644 --- a/arch/mips/include/asm/page.h +++ b/arch/mips/include/asm/page.h @@ -11,6 +11,8 @@ #include #include +#include +#include /* * PAGE_SHIFT determines the page size @@ -33,6 +35,29 @@ #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1)) +/* + * This is used for calculating the real page sizes + * for FTLB or VTLB + FTLB confugrations. + */ +static inline unsigned int page_size_ftlb(unsigned int mmuextdef) +{ + switch (mmuextdef) { + case MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT: + if (PAGE_SIZE == (1 << 30)) + return 5; + if (PAGE_SIZE == (1llu << 32)) + return 6; + if (PAGE_SIZE > (256 << 10)) + return 7; /* reserved */ + /* fall through */ + case MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT: + return (PAGE_SHIFT - 10) / 2; + default: + panic("Invalid FTLB configuration with Conf4_mmuextdef=%d value\n", + mmuextdef >> 14); + } +} + #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT #define HPAGE_SHIFT (PAGE_SHIFT + PAGE_SHIFT - 3) #define HPAGE_SIZE (_AC(1,UL) << HPAGE_SHIFT) diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index f86414e..65b61bb 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -163,6 +163,25 @@ static void set_isa(struct cpuinfo_mips *c, unsigned int isa) static char unknown_isa[] = KERN_ERR \ "Unsupported ISA type, c0.config0: %d."; +static void set_ftlb_enable(struct cpuinfo_mips *c, int enable) +{ + unsigned int config6; + /* + * Config6 is implementation dependent and it's currently only + * used by proAptiv + */ + if (c->cputype == CPU_PROAPTIV) { + config6 = read_c0_config6(); + if (enable) + /* Enable FTLB */ + write_c0_config6(config6 | MIPS_CONF6_FTLBEN); + else + /* Disable FTLB */ + write_c0_config6(config6 & ~MIPS_CONF6_FTLBEN); + back_to_back_c0_hazard(); + } +} + static inline unsigned int decode_config0(struct cpuinfo_mips *c) { unsigned int config0; @@ -170,8 +189,13 @@ static inline unsigned int decode_config0(struct cpuinfo_mips *c) config0 = read_c0_config(); - if (((config0 & MIPS_CONF_MT) >> 7) == 1) + /* + * Look for Standard TLB or Dual VTLB and FTLB + */ + if ((((config0 & MIPS_CONF_MT) >> 7) == 1) || + (((config0 & MIPS_CONF_MT) >> 7) == 4)) c->options |= MIPS_CPU_TLB; + isa = (config0 & MIPS_CONF_AT) >> 13; switch (isa) { case 0: @@ -226,8 +250,11 @@ static inline unsigned int decode_config1(struct cpuinfo_mips *c) c->options |= MIPS_CPU_FPU; c->options |= MIPS_CPU_32FPR; } - if (cpu_has_tlb) + if (cpu_has_tlb) { c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1; + c->tlbsizevtlb = c->tlbsize; + c->tlbsizeftlbsets = 0; + } return config1 & MIPS_CONF_M; } @@ -281,16 +308,50 @@ static inline unsigned int decode_config3(struct cpuinfo_mips *c) static inline unsigned int decode_config4(struct cpuinfo_mips *c) { unsigned int config4; + unsigned int newcf4; + unsigned int mmuextdef; + unsigned int ftlb_page = MIPS_CONF4_FTLBPAGESIZE; config4 = read_c0_config4(); - if ((config4 & MIPS_CONF4_MMUEXTDEF) == MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT - && cpu_has_tlb) - c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40; - if (cpu_has_tlb) { if (((config4 & MIPS_CONF4_IE) >> 29) == 2) c->options |= MIPS_CPU_TLBINV; + mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF; + switch (mmuextdef) { + case MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT: + c->tlbsize += (config4 & MIPS_CONF4_MMUSIZEEXT) * 0x40; + c->tlbsizevtlb = c->tlbsize; + break; + case MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT: + c->tlbsizevtlb += + ((config4 & MIPS_CONF4_VTLBSIZEEXT) >> + MIPS_CONF4_VTLBSIZEEXT_SHIFT) * 0x40; + c->tlbsize = c->tlbsizevtlb; + ftlb_page = MIPS_CONF4_VFTLBPAGESIZE; + /* fall through */ + case MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT: + newcf4 = (config4 & ~ftlb_page) | + (page_size_ftlb(mmuextdef) << + MIPS_CONF4_FTLBPAGESIZE_SHIFT); + write_c0_config4(newcf4); + back_to_back_c0_hazard(); + config4 = read_c0_config4(); + if (config4 != newcf4) { + pr_err("PAGE_SIZE 0x%lx is not supported by FTLB (config4=0x%x)\n", + PAGE_SIZE, config4); + /* Switch FTLB off */ + set_ftlb_enable(c, 0); + break; + } + c->tlbsizeftlbsets = 1 << + ((config4 & MIPS_CONF4_FTLBSETS) >> + MIPS_CONF4_FTLBSETS_SHIFT); + c->tlbsizeftlbways = ((config4 & MIPS_CONF4_FTLBWAYS) >> + MIPS_CONF4_FTLBWAYS_SHIFT) + 2; + c->tlbsize += c->tlbsizeftlbways * c->tlbsizeftlbsets; + break; + } } c->kscratch_mask = (config4 >> 16) & 0xff; @@ -319,6 +380,9 @@ static void decode_configs(struct cpuinfo_mips *c) c->scache.flags = MIPS_CACHE_NOT_PRESENT; + /* Enable FTLB if present */ + set_ftlb_enable(c, 1); + ok = decode_config0(c); /* Read Config registers. */ BUG_ON(!ok); /* Arch spec violation! */ if (ok) @@ -682,7 +746,6 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu) { - decode_configs(c); switch (c->processor_id & PRID_IMP_MASK) { case PRID_IMP_4KC: c->cputype = CPU_4KC; @@ -756,6 +819,8 @@ static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu) break; } + decode_configs(c); + spram_config(); } diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S index 47d7583..d84f6a5 100644 --- a/arch/mips/kernel/genex.S +++ b/arch/mips/kernel/genex.S @@ -476,6 +476,7 @@ NESTED(nmi_handler, PT_SIZE, sp) BUILD_HANDLER ov ov sti silent /* #12 */ BUILD_HANDLER tr tr sti silent /* #13 */ BUILD_HANDLER fpe fpe fpe silent /* #15 */ + BUILD_HANDLER ftlb ftlb none silent /* #16 */ BUILD_HANDLER mdmx mdmx sti silent /* #22 */ #ifdef CONFIG_HARDWARE_WATCHPOINTS /* diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index e98f3ab..39370e1 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -78,6 +78,7 @@ extern asmlinkage void handle_cpu(void); extern asmlinkage void handle_ov(void); extern asmlinkage void handle_tr(void); extern asmlinkage void handle_fpe(void); +extern asmlinkage void handle_ftlb(void); extern asmlinkage void handle_mdmx(void); extern asmlinkage void handle_watch(void); extern asmlinkage void handle_mt(void); @@ -1460,6 +1461,34 @@ asmlinkage void cache_parity_error(void) panic("Can't handle the cache error!"); } +asmlinkage void do_ftlb(void) +{ + const int field = 2 * sizeof(unsigned long); + unsigned int reg_val; + + /* For the moment, report the problem and hang. */ + if (cpu_has_mips_r2 && + ((current_cpu_data.processor_id && 0xff0000) == PRID_COMP_MIPS)) { + pr_err("FTLB error exception, cp0_ecc=0x%08x:\n", + read_c0_ecc()); + pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc()); + reg_val = read_c0_cacheerr(); + pr_err("c0_cacheerr == %08x\n", reg_val); + + if ((reg_val & 0xc0000000) == 0xc0000000) { + pr_err("Decoded c0_cacheerr: FTLB parity error\n"); + } else { + pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n", + reg_val & (1<<30) ? "secondary" : "primary", + reg_val & (1<<31) ? "data" : "insn"); + } + } else { + pr_err("FTLB error exception\n"); + } + /* Just print the cacheerr bits for now */ + cache_parity_error(); +} + /* * SDBBP EJTAG debug exception handler. * We skip the instruction and return to the next instruction. @@ -2009,6 +2038,7 @@ void __init trap_init(void) if (cpu_has_fpu && !cpu_has_nofpuex) set_except_vector(15, handle_fpe); + set_except_vector(16, handle_ftlb); set_except_vector(22, handle_mdmx); if (cpu_has_mcheck) diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c index 427dcac..ae4ca24 100644 --- a/arch/mips/mm/tlb-r4k.c +++ b/arch/mips/mm/tlb-r4k.c @@ -72,7 +72,7 @@ void local_flush_tlb_all(void) { unsigned long flags; unsigned long old_ctx; - int entry; + int entry, ftlbhighset; ENTER_CRITICAL(flags); /* Save old context and create impossible VPN2 value */ @@ -83,10 +83,21 @@ void local_flush_tlb_all(void) entry = read_c0_wired(); /* Blast 'em all away. */ - if (cpu_has_tlbinv && current_cpu_data.tlbsize) { - write_c0_index(0); - mtc0_tlbw_hazard(); - tlbinvf(); /* invalidate VTLB */ + if (cpu_has_tlbinv) { + if (current_cpu_data.tlbsizevtlb) { + write_c0_index(0); + mtc0_tlbw_hazard(); + tlbinvf(); /* invalidate VTLB */ + } + ftlbhighset = current_cpu_data.tlbsizevtlb + + current_cpu_data.tlbsizeftlbsets; + for (entry = current_cpu_data.tlbsizevtlb; + entry < ftlbhighset; + entry++) { + write_c0_index(entry); + mtc0_tlbw_hazard(); + tlbinvf(); /* invalidate one FTLB set */ + } } else { while (entry < current_cpu_data.tlbsize) { /* Make sure all entries differ. */ @@ -134,7 +145,9 @@ void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start, start = round_down(start, PAGE_SIZE << 1); end = round_up(end, PAGE_SIZE << 1); size = (end - start) >> (PAGE_SHIFT + 1); - if (size <= current_cpu_data.tlbsize/2) { + if (size <= (current_cpu_data.tlbsizeftlbsets ? + current_cpu_data.tlbsize / 8 : + current_cpu_data.tlbsize / 2)) { int oldpid = read_c0_entryhi(); int newpid = cpu_asid(cpu, mm); @@ -173,7 +186,9 @@ void local_flush_tlb_kernel_range(unsigned long start, unsigned long end) ENTER_CRITICAL(flags); size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT; size = (size + 1) >> 1; - if (size <= current_cpu_data.tlbsize / 2) { + if (size <= (current_cpu_data.tlbsizeftlbsets ? + current_cpu_data.tlbsize / 8 : + current_cpu_data.tlbsize / 2)) { int pid = read_c0_entryhi(); start &= (PAGE_MASK << 1); -- 2.7.4