From 380cd582c08831217ae693c86411902e6300ba6b Mon Sep 17 00:00:00 2001 From: Huacai Chen Date: Thu, 3 Mar 2016 09:45:12 +0800 Subject: 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/mm/tlbex.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 121 insertions(+), 3 deletions(-) (limited to 'arch/mips/mm/tlbex.c') diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index 84c6e3fda84a..7153e1fb0cd4 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++; -- cgit v1.2.3