From 4f12b91d2da577d81c580da62373fd37b31e0da1 Mon Sep 17 00:00:00 2001 From: Markos Chandras Date: Fri, 18 Jul 2014 10:51:32 +0100 Subject: [PATCH] MIPS: cpu-probe: Set the write-combine CCA value on per core basis Different cores use different CCA values to achieve write-combine memory writes. For cores that do not support write-combine we set the default value to CCA:2 (uncached, non-coherent) which is the default value as set by the kernel. Signed-off-by: Markos Chandras Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7402/ Signed-off-by: Ralf Baechle --- arch/mips/include/asm/cpu-info.h | 5 +++++ arch/mips/kernel/cpu-probe.c | 21 +++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h index d5f42c168001..a6c9ccb33c5c 100644 --- a/arch/mips/include/asm/cpu-info.h +++ b/arch/mips/include/asm/cpu-info.h @@ -79,6 +79,11 @@ struct cpuinfo_mips { #define NUM_WATCH_REGS 4 u16 watch_reg_masks[NUM_WATCH_REGS]; unsigned int kscratch_mask; /* Usable KScratch mask. */ + /* + * Cache Coherency attribute for write-combine memory writes. + * (shifted by _CACHE_SHIFT) + */ + unsigned int writecombine; } __attribute__((aligned(SMP_CACHE_BYTES))); extern struct cpuinfo_mips cpu_data[]; diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index e34b10be782e..94c4a0c0a577 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -764,6 +765,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) break; case PRID_REV_LOONGSON3A: c->cputype = CPU_LOONGSON3; + c->writecombine = _CACHE_UNCACHED_ACCELERATED; __cpu_name[cpu] = "ICT Loongson-3"; set_elf_platform(cpu, "loongson3a"); break; @@ -798,67 +800,83 @@ 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) { + c->writecombine = _CACHE_UNCACHED_ACCELERATED; switch (c->processor_id & PRID_IMP_MASK) { case PRID_IMP_4KC: c->cputype = CPU_4KC; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 4Kc"; break; case PRID_IMP_4KEC: case PRID_IMP_4KECR2: c->cputype = CPU_4KEC; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 4KEc"; break; case PRID_IMP_4KSC: case PRID_IMP_4KSD: c->cputype = CPU_4KSC; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 4KSc"; break; case PRID_IMP_5KC: c->cputype = CPU_5KC; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 5Kc"; break; case PRID_IMP_5KE: c->cputype = CPU_5KE; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 5KE"; break; case PRID_IMP_20KC: c->cputype = CPU_20KC; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 20Kc"; break; case PRID_IMP_24K: c->cputype = CPU_24K; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 24Kc"; break; case PRID_IMP_24KE: c->cputype = CPU_24K; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 24KEc"; break; case PRID_IMP_25KF: c->cputype = CPU_25KF; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 25Kc"; break; case PRID_IMP_34K: c->cputype = CPU_34K; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 34Kc"; break; case PRID_IMP_74K: c->cputype = CPU_74K; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 74Kc"; break; case PRID_IMP_M14KC: c->cputype = CPU_M14KC; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS M14Kc"; break; case PRID_IMP_M14KEC: c->cputype = CPU_M14KEC; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS M14KEc"; break; case PRID_IMP_1004K: c->cputype = CPU_1004K; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 1004Kc"; break; case PRID_IMP_1074K: c->cputype = CPU_1074K; + c->writecombine = _CACHE_UNCACHED; __cpu_name[cpu] = "MIPS 1074Kc"; break; case PRID_IMP_INTERAPTIV_UP: @@ -932,6 +950,7 @@ static inline void cpu_probe_sibyte(struct cpuinfo_mips *c, unsigned int cpu) { decode_configs(c); + c->writecombine = _CACHE_UNCACHED_ACCELERATED; switch (c->processor_id & PRID_IMP_MASK) { case PRID_IMP_SB1: c->cputype = CPU_SB1; @@ -1063,6 +1082,7 @@ static inline void cpu_probe_ingenic(struct cpuinfo_mips *c, unsigned int cpu) switch (c->processor_id & PRID_IMP_MASK) { case PRID_IMP_JZRISC: c->cputype = CPU_JZRISC; + c->writecombine = _CACHE_UNCACHED_ACCELERATED; __cpu_name[cpu] = "Ingenic JZRISC"; break; default: @@ -1169,6 +1189,7 @@ void cpu_probe(void) c->processor_id = PRID_IMP_UNKNOWN; c->fpu_id = FPIR_IMP_NONE; c->cputype = CPU_UNKNOWN; + c->writecombine = _CACHE_UNCACHED; c->processor_id = read_c0_prid(); switch (c->processor_id & PRID_COMP_MASK) {