From 380cd582c08831217ae693c86411902e6300ba6b Mon Sep 17 00:00:00 2001 From: Huacai Chen Date: Thu, 3 Mar 2016 09:45:12 +0800 Subject: [PATCH] MIPS: Loongson-3: Fast TLB refill handler Loongson-3A R2 has pwbase/pwfield/pwsize/pwctl registers in CP0 (this is very similar to HTW) and lwdir/lwpte/lddir/ldpte instructions which can be used for fast TLB refill. [ralf@linux-mips.org: Resolve conflict.] Signed-off-by: Huacai Chen Cc: Aurelien Jarno Cc: Steven J . Hill Cc: Fuxin Zhang Cc: Zhangjin Wu Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12754/ Signed-off-by: Ralf Baechle --- arch/mips/include/asm/cpu-features.h | 3 + arch/mips/include/asm/cpu.h | 1 + arch/mips/include/asm/mipsregs.h | 6 ++ arch/mips/include/asm/uasm.h | 3 +- arch/mips/include/uapi/asm/inst.h | 10 +++ arch/mips/kernel/cpu-probe.c | 2 +- arch/mips/mm/tlbex.c | 124 ++++++++++++++++++++++++++++++++++- arch/mips/mm/uasm-mips.c | 2 + arch/mips/mm/uasm.c | 3 + 9 files changed, 149 insertions(+), 5 deletions(-) diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h index 6ff0504..da92d51 100644 --- a/arch/mips/include/asm/cpu-features.h +++ b/arch/mips/include/asm/cpu-features.h @@ -35,6 +35,9 @@ #ifndef cpu_has_htw #define cpu_has_htw (cpu_data[0].options & MIPS_CPU_HTW) #endif +#ifndef cpu_has_ldpte +#define cpu_has_ldpte (cpu_data[0].options & MIPS_CPU_LDPTE) +#endif #ifndef cpu_has_rixiex #define cpu_has_rixiex (cpu_data[0].options & MIPS_CPU_RIXIEX) #endif diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h index 810536b..d9150a2 100644 --- a/arch/mips/include/asm/cpu.h +++ b/arch/mips/include/asm/cpu.h @@ -402,6 +402,7 @@ enum cpu_type_enum { #define MIPS_CPU_NAN_LEGACY MBIT_ULL(38) /* Legacy NaN implemented */ #define MIPS_CPU_NAN_2008 MBIT_ULL(39) /* 2008 NaN implemented */ #define MIPS_CPU_VP MBIT_ULL(40) /* MIPSr6 Virtual Processors (multi-threading) */ +#define MIPS_CPU_LDPTE MBIT_ULL(41) /* CPU has ldpte/lddir instructions */ /* * CPU ASE encodings diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h index 0d0bd16..1e9d337 100644 --- a/arch/mips/include/asm/mipsregs.h +++ b/arch/mips/include/asm/mipsregs.h @@ -1474,6 +1474,12 @@ do { \ #define read_c0_pwctl() __read_32bit_c0_register($6, 6) #define write_c0_pwctl(val) __write_32bit_c0_register($6, 6, val) +#define read_c0_pgd() __read_64bit_c0_register($9, 7) +#define write_c0_pgd(val) __write_64bit_c0_register($9, 7, val) + +#define read_c0_kpgd() __read_64bit_c0_register($31, 7) +#define write_c0_kpgd(val) __write_64bit_c0_register($31, 7, val) + /* Cavium OCTEON (cnMIPS) */ #define read_c0_cvmcount() __read_ulong_c0_register($9, 6) #define write_c0_cvmcount(val) __write_ulong_c0_register($9, 6, val) diff --git a/arch/mips/include/asm/uasm.h b/arch/mips/include/asm/uasm.h index fc1cdd2..b6ecfee 100644 --- a/arch/mips/include/asm/uasm.h +++ b/arch/mips/include/asm/uasm.h @@ -171,7 +171,8 @@ Ip_u2u1(_wsbh); Ip_u3u1u2(_xor); Ip_u2u1u3(_xori); Ip_u2u1(_yield); - +Ip_u1u2(_ldpte); +Ip_u2u1u3(_lddir); /* Handle labels. */ struct uasm_label { diff --git a/arch/mips/include/uapi/asm/inst.h b/arch/mips/include/uapi/asm/inst.h index ddea53e..3bb8cd9 100644 --- a/arch/mips/include/uapi/asm/inst.h +++ b/arch/mips/include/uapi/asm/inst.h @@ -204,6 +204,16 @@ enum mad_func { }; /* + * func field for page table walker (Loongson-3). + */ +enum ptw_func { + lwdir_op = 0x00, + lwpte_op = 0x01, + lddir_op = 0x02, + ldpte_op = 0x03, +}; + +/* * func field for special3 lx opcodes (Cavium Octeon). */ enum lx_func { diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 515dd1f..064ab38 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -1539,7 +1539,7 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) } decode_configs(c); - c->options |= MIPS_CPU_TLBINV; + c->options |= MIPS_CPU_TLBINV | MIPS_CPU_LDPTE; c->writecombine = _CACHE_UNCACHED_ACCELERATED; break; default: diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index 84c6e3f..7153e1f 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -284,7 +284,12 @@ static inline void dump_handler(const char *symbol, const u32 *handler, int coun #define C0_ENTRYLO1 3, 0 #define C0_CONTEXT 4, 0 #define C0_PAGEMASK 5, 0 +#define C0_PWBASE 5, 5 +#define C0_PWFIELD 5, 6 +#define C0_PWSIZE 5, 7 +#define C0_PWCTL 6, 6 #define C0_BADVADDR 8, 0 +#define C0_PGD 9, 7 #define C0_ENTRYHI 10, 0 #define C0_EPC 14, 0 #define C0_XCONTEXT 20, 0 @@ -808,7 +813,10 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, if (pgd_reg != -1) { /* pgd is in pgd_reg */ - UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg); + if (cpu_has_ldpte) + UASM_i_MFC0(p, ptr, C0_PWBASE); + else + UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg); } else { #if defined(CONFIG_MIPS_PGD_C0_CONTEXT) /* @@ -1421,6 +1429,108 @@ static void build_r4000_tlb_refill_handler(void) dump_handler("r4000_tlb_refill", (u32 *)ebase, 64); } +static void setup_pw(void) +{ + unsigned long pgd_i, pgd_w; +#ifndef __PAGETABLE_PMD_FOLDED + unsigned long pmd_i, pmd_w; +#endif + unsigned long pt_i, pt_w; + unsigned long pte_i, pte_w; +#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT + unsigned long psn; + + psn = ilog2(_PAGE_HUGE); /* bit used to indicate huge page */ +#endif + pgd_i = PGDIR_SHIFT; /* 1st level PGD */ +#ifndef __PAGETABLE_PMD_FOLDED + pgd_w = PGDIR_SHIFT - PMD_SHIFT + PGD_ORDER; + + pmd_i = PMD_SHIFT; /* 2nd level PMD */ + pmd_w = PMD_SHIFT - PAGE_SHIFT; +#else + pgd_w = PGDIR_SHIFT - PAGE_SHIFT + PGD_ORDER; +#endif + + pt_i = PAGE_SHIFT; /* 3rd level PTE */ + pt_w = PAGE_SHIFT - 3; + + pte_i = ilog2(_PAGE_GLOBAL); + pte_w = 0; + +#ifndef __PAGETABLE_PMD_FOLDED + write_c0_pwfield(pgd_i << 24 | pmd_i << 12 | pt_i << 6 | pte_i); + write_c0_pwsize(1 << 30 | pgd_w << 24 | pmd_w << 12 | pt_w << 6 | pte_w); +#else + write_c0_pwfield(pgd_i << 24 | pt_i << 6 | pte_i); + write_c0_pwsize(1 << 30 | pgd_w << 24 | pt_w << 6 | pte_w); +#endif + +#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT + write_c0_pwctl(1 << 6 | psn); +#endif + write_c0_kpgd(swapper_pg_dir); + kscratch_used_mask |= (1 << 7); /* KScratch6 is used for KPGD */ +} + +static void build_loongson3_tlb_refill_handler(void) +{ + u32 *p = tlb_handler; + struct uasm_label *l = labels; + struct uasm_reloc *r = relocs; + + memset(labels, 0, sizeof(labels)); + memset(relocs, 0, sizeof(relocs)); + memset(tlb_handler, 0, sizeof(tlb_handler)); + + if (check_for_high_segbits) { + uasm_i_dmfc0(&p, K0, C0_BADVADDR); + uasm_i_dsrl_safe(&p, K1, K0, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3); + uasm_il_beqz(&p, &r, K1, label_vmalloc); + uasm_i_nop(&p); + + uasm_il_bgez(&p, &r, K0, label_large_segbits_fault); + uasm_i_nop(&p); + uasm_l_vmalloc(&l, p); + } + + uasm_i_dmfc0(&p, K1, C0_PGD); + + uasm_i_lddir(&p, K0, K1, 3); /* global page dir */ +#ifndef __PAGETABLE_PMD_FOLDED + uasm_i_lddir(&p, K1, K0, 1); /* middle page dir */ +#endif + uasm_i_ldpte(&p, K1, 0); /* even */ + uasm_i_ldpte(&p, K1, 1); /* odd */ + uasm_i_tlbwr(&p); + + /* restore page mask */ + if (PM_DEFAULT_MASK >> 16) { + uasm_i_lui(&p, K0, PM_DEFAULT_MASK >> 16); + uasm_i_ori(&p, K0, K0, PM_DEFAULT_MASK & 0xffff); + uasm_i_mtc0(&p, K0, C0_PAGEMASK); + } else if (PM_DEFAULT_MASK) { + uasm_i_ori(&p, K0, 0, PM_DEFAULT_MASK); + uasm_i_mtc0(&p, K0, C0_PAGEMASK); + } else { + uasm_i_mtc0(&p, 0, C0_PAGEMASK); + } + + uasm_i_eret(&p); + + if (check_for_high_segbits) { + uasm_l_large_segbits_fault(&l, p); + UASM_i_LA(&p, K1, (unsigned long)tlb_do_page_fault_0); + uasm_i_jr(&p, K1); + uasm_i_nop(&p); + } + + uasm_resolve_relocs(relocs, labels); + memcpy((void *)(ebase + 0x80), tlb_handler, 0x80); + local_flush_icache_range(ebase + 0x80, ebase + 0x100); + dump_handler("loongson3_tlb_refill", (u32 *)(ebase + 0x80), 32); +} + extern u32 handle_tlbl[], handle_tlbl_end[]; extern u32 handle_tlbs[], handle_tlbs_end[]; extern u32 handle_tlbm[], handle_tlbm_end[]; @@ -1468,7 +1578,10 @@ static void build_setup_pgd(void) } else { /* PGD in c0_KScratch */ uasm_i_jr(&p, 31); - UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg); + if (cpu_has_ldpte) + UASM_i_MTC0(&p, a0, C0_PWBASE); + else + UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg); } #else #ifdef CONFIG_SMP @@ -2437,13 +2550,18 @@ void build_tlb_refill_handler(void) break; default: + if (cpu_has_ldpte) + setup_pw(); + if (!run_once) { scratch_reg = allocate_kscratch(); build_setup_pgd(); build_r4000_tlb_load_handler(); build_r4000_tlb_store_handler(); build_r4000_tlb_modify_handler(); - if (!cpu_has_local_ebase) + if (cpu_has_ldpte) + build_loongson3_tlb_refill_handler(); + else if (!cpu_has_local_ebase) build_r4000_tlb_refill_handler(); flush_tlb_handlers(); run_once++; diff --git a/arch/mips/mm/uasm-mips.c b/arch/mips/mm/uasm-mips.c index b4a83789..9c2220a 100644 --- a/arch/mips/mm/uasm-mips.c +++ b/arch/mips/mm/uasm-mips.c @@ -153,6 +153,8 @@ static struct insn insn_table[] = { { insn_xori, M(xori_op, 0, 0, 0, 0, 0), RS | RT | UIMM }, { insn_xor, M(spec_op, 0, 0, 0, 0, xor_op), RS | RT | RD }, { insn_yield, M(spec3_op, 0, 0, 0, 0, yield_op), RS | RD }, + { insn_ldpte, M(lwc2_op, 0, 0, 0, ldpte_op, mult_op), RS | RD }, + { insn_lddir, M(lwc2_op, 0, 0, 0, lddir_op, mult_op), RS | RT | RD }, { insn_invalid, 0, 0 } }; diff --git a/arch/mips/mm/uasm.c b/arch/mips/mm/uasm.c index 319051c..ad718de 100644 --- a/arch/mips/mm/uasm.c +++ b/arch/mips/mm/uasm.c @@ -60,6 +60,7 @@ enum opcode { insn_sltiu, insn_sltu, insn_sra, insn_srl, insn_srlv, insn_subu, insn_sw, insn_sync, insn_syscall, insn_tlbp, insn_tlbr, insn_tlbwi, insn_tlbwr, insn_wait, insn_wsbh, insn_xor, insn_xori, insn_yield, + insn_lddir, insn_ldpte, }; struct insn { @@ -335,6 +336,8 @@ I_u1u2s3(_bbit0); I_u1u2s3(_bbit1); I_u3u1u2(_lwx) I_u3u1u2(_ldx) +I_u1u2(_ldpte) +I_u2u1u3(_lddir) #ifdef CONFIG_CPU_CAVIUM_OCTEON #include -- 2.7.4