From d1f317d8254413447bcd6b6adbde24a985d256c2 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Mon, 6 Apr 2015 17:23:57 +0530 Subject: [PATCH] ARCv2: MMUv4: cache programming model changes Caveats about cache flush on ARCv2 based cores - dcache is PIPT so paddr is sufficient for cache maintenance ops (no need to setup PTAG reg - icache is still VIPT but only aliasing configs need PTAG setup So basically this is departure from MMU-v3 which always need vaddr in line ops registers (DC_IVDL, DC_FLDL, IC_IVIL) but paddr in DC_PTAG, IC_PTAG respectively. Signed-off-by: Vineet Gupta --- arch/arc/Kconfig | 2 +- arch/arc/include/asm/arcregs.h | 5 +- arch/arc/include/asm/cache.h | 3 + arch/arc/mm/cache.c | 112 ++++++++++++++++++++++++++++----- 4 files changed, 104 insertions(+), 18 deletions(-) diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index 6568977bb302..974ed9058018 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -223,7 +223,7 @@ config ARC_CACHE_PAGES config ARC_CACHE_VIPT_ALIASING bool "Support VIPT Aliasing D$" - depends on ARC_HAS_DCACHE + depends on ARC_HAS_DCACHE && ISA_ARCOMPACT default n endif #ARC_CACHE diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h index bcb08cd52d38..070f58827a5c 100644 --- a/arch/arc/include/asm/arcregs.h +++ b/arch/arc/include/asm/arcregs.h @@ -17,6 +17,7 @@ #define ARC_REG_FP_BCR 0x6B /* ARCompact: Single-Precision FPU */ #define ARC_REG_DPFP_BCR 0x6C /* ARCompact: Dbl Precision FPU */ #define ARC_REG_FP_V2_BCR 0xc8 /* ARCv2 FPU */ +#define ARC_REG_SLC_BCR 0xce #define ARC_REG_DCCM_BCR 0x74 /* DCCM Present + SZ */ #define ARC_REG_TIMERS_BCR 0x75 #define ARC_REG_AP_BCR 0x76 @@ -331,7 +332,7 @@ struct cpuinfo_arc_mmu { }; struct cpuinfo_arc_cache { - unsigned int sz_k:8, line_len:8, assoc:4, ver:4, alias:1, vipt:1, pad:6; + unsigned int sz_k:14, line_len:8, assoc:4, ver:4, alias:1, vipt:1; }; struct cpuinfo_arc_bpu { @@ -343,7 +344,7 @@ struct cpuinfo_arc_ccm { }; struct cpuinfo_arc { - struct cpuinfo_arc_cache icache, dcache; + struct cpuinfo_arc_cache icache, dcache, slc; struct cpuinfo_arc_mmu mmu; struct cpuinfo_arc_bpu bpu; struct bcr_identity core; diff --git a/arch/arc/include/asm/cache.h b/arch/arc/include/asm/cache.h index 7861255da32d..e54977a7d006 100644 --- a/arch/arc/include/asm/cache.h +++ b/arch/arc/include/asm/cache.h @@ -82,4 +82,7 @@ extern void read_decode_cache_bcr(void); #define DC_CTRL_INV_MODE_FLUSH 0x40 #define DC_CTRL_FLUSH_STATUS 0x100 +/*System-level cache (L2 cache) related Auxiliary registers */ +#define ARC_REG_SLC_CFG 0x901 + #endif /* _ASM_CACHE_H */ diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c index 6fa5f0f7f549..7a898f57d84b 100644 --- a/arch/arc/mm/cache.c +++ b/arch/arc/mm/cache.c @@ -24,6 +24,7 @@ char *arc_cache_mumbojumbo(int c, char *buf, int len) { int n = 0; + struct cpuinfo_arc_cache *p; #define PR_CACHE(p, cfg, str) \ if (!(p)->ver) \ @@ -39,6 +40,11 @@ char *arc_cache_mumbojumbo(int c, char *buf, int len) PR_CACHE(&cpuinfo_arc700[c].icache, CONFIG_ARC_HAS_ICACHE, "I-Cache"); PR_CACHE(&cpuinfo_arc700[c].dcache, CONFIG_ARC_HAS_DCACHE, "D-Cache"); + p = &cpuinfo_arc700[c].slc; + if (p->ver) + n += scnprintf(buf + n, len - n, + "SLC\t\t: %uK, %uB Line\n", p->sz_k, p->line_len); + return buf; } @@ -49,7 +55,7 @@ char *arc_cache_mumbojumbo(int c, char *buf, int len) */ void read_decode_cache_bcr(void) { - struct cpuinfo_arc_cache *p_ic, *p_dc; + struct cpuinfo_arc_cache *p_ic, *p_dc, *p_slc; unsigned int cpu = smp_processor_id(); struct bcr_cache { #ifdef CONFIG_CPU_BIG_ENDIAN @@ -59,14 +65,29 @@ void read_decode_cache_bcr(void) #endif } ibcr, dbcr; + struct bcr_generic sbcr; + + struct bcr_slc_cfg { +#ifdef CONFIG_CPU_BIG_ENDIAN + unsigned int pad:24, way:2, lsz:2, sz:4; +#else + unsigned int sz:4, lsz:2, way:2, pad:24; +#endif + } slc_cfg; + p_ic = &cpuinfo_arc700[cpu].icache; READ_BCR(ARC_REG_IC_BCR, ibcr); if (!ibcr.ver) goto dc_chk; - BUG_ON(ibcr.config != 3); - p_ic->assoc = 2; /* Fixed to 2w set assoc */ + if (ibcr.ver <= 3) { + BUG_ON(ibcr.config != 3); + p_ic->assoc = 2; /* Fixed to 2w set assoc */ + } else if (ibcr.ver >= 4) { + p_ic->assoc = 1 << ibcr.config; /* 1,2,4,8 */ + } + p_ic->line_len = 8 << ibcr.line_len; p_ic->sz_k = 1 << (ibcr.sz - 1); p_ic->ver = ibcr.ver; @@ -78,15 +99,32 @@ dc_chk: READ_BCR(ARC_REG_DC_BCR, dbcr); if (!dbcr.ver) - return; + goto slc_chk; + + if (dbcr.ver <= 3) { + BUG_ON(dbcr.config != 2); + p_dc->assoc = 4; /* Fixed to 4w set assoc */ + p_dc->vipt = 1; + p_dc->alias = p_dc->sz_k/p_dc->assoc/TO_KB(PAGE_SIZE) > 1; + } else if (dbcr.ver >= 4) { + p_dc->assoc = 1 << dbcr.config; /* 1,2,4,8 */ + p_dc->vipt = 0; + p_dc->alias = 0; /* PIPT so can't VIPT alias */ + } - BUG_ON(dbcr.config != 2); - p_dc->assoc = 4; /* Fixed to 4w set assoc */ p_dc->line_len = 16 << dbcr.line_len; p_dc->sz_k = 1 << (dbcr.sz - 1); p_dc->ver = dbcr.ver; - p_dc->vipt = 1; - p_dc->alias = p_dc->sz_k/p_dc->assoc/TO_KB(PAGE_SIZE) > 1; + +slc_chk: + p_slc = &cpuinfo_arc700[cpu].slc; + READ_BCR(ARC_REG_SLC_BCR, sbcr); + if (sbcr.ver) { + READ_BCR(ARC_REG_SLC_CFG, slc_cfg); + p_slc->ver = sbcr.ver; + p_slc->sz_k = 128 << slc_cfg.sz; + p_slc->line_len = (slc_cfg.lsz == 0) ? 128 : 64; + } } /* @@ -225,10 +263,53 @@ void __cache_line_loop_v3(unsigned long paddr, unsigned long vaddr, } } +/* + * In HS38x (MMU v4), although icache is VIPT, only paddr is needed for cache + * maintenance ops (in IVIL reg), as long as icache doesn't alias. + * + * For Aliasing icache, vaddr is also needed (in IVIL), while paddr is + * specified in PTAG (similar to MMU v3) + */ +static inline +void __cache_line_loop_v4(unsigned long paddr, unsigned long vaddr, + unsigned long sz, const int cacheop) +{ + unsigned int aux_cmd; + int num_lines; + const int full_page_op = __builtin_constant_p(sz) && sz == PAGE_SIZE; + + if (cacheop == OP_INV_IC) { + aux_cmd = ARC_REG_IC_IVIL; + } else { + /* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */ + aux_cmd = cacheop & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL; + } + + /* Ensure we properly floor/ceil the non-line aligned/sized requests + * and have @paddr - aligned to cache line and integral @num_lines. + * This however can be avoided for page sized since: + * -@paddr will be cache-line aligned already (being page aligned) + * -@sz will be integral multiple of line size (being page sized). + */ + if (!full_page_op) { + sz += paddr & ~CACHE_LINE_MASK; + paddr &= CACHE_LINE_MASK; + } + + num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES); + + while (num_lines-- > 0) { + write_aux_reg(aux_cmd, paddr); + paddr += L1_CACHE_BYTES; + } +} + #if (CONFIG_ARC_MMU_VER < 3) #define __cache_line_loop __cache_line_loop_v2 #elif (CONFIG_ARC_MMU_VER == 3) #define __cache_line_loop __cache_line_loop_v3 +#elif (CONFIG_ARC_MMU_VER > 3) +#define __cache_line_loop __cache_line_loop_v4 #endif #ifdef CONFIG_ARC_HAS_DCACHE @@ -669,7 +750,6 @@ void arc_cache_init(void) if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE)) { struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache; - int handled; if (!dc->ver) panic("cache support enabled but non-existent cache\n"); @@ -678,12 +758,14 @@ void arc_cache_init(void) panic("DCache line [%d] != kernel Config [%d]", dc->line_len, L1_CACHE_BYTES); - /* check for D-Cache aliasing */ - handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING); + /* check for D-Cache aliasing on ARCompact: ARCv2 has PIPT */ + if (is_isa_arcompact()) { + int handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING); - if (dc->alias && !handled) - panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n"); - else if (!dc->alias && handled) - panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n"); + if (dc->alias && !handled) + panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n"); + else if (!dc->alias && handled) + panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n"); + } } } -- 2.30.2