From 5aed9da128be27275b0892fb413f3a0af64e00a6 Mon Sep 17 00:00:00 2001 From: Markos Chandras Date: Tue, 2 Dec 2014 09:46:19 +0000 Subject: [PATCH] MIPS: Add LLB bit and related feature for the Config 5 CP0 register The LLBIT (bit 4) in the Config5 CP0 register indicates the software availability of the Load-Linked bit. This bit is only set by hardware and it has the following meaning: 0: LLB functionality is not supported 1: LLB functionality is supported. The following feature are also supported: - ERETNC instruction. Similar to ERET but it does not clear the LLB bit in the LLAddr register. - CP0 LLAddr/LLB bit must be set - LLbit is software accessible through the LLAddr[0] This will be used later on to emulate R2 LL/SC instructions. Signed-off-by: Markos Chandras --- arch/mips/include/asm/cpu-features.h | 3 +++ arch/mips/include/asm/cpu.h | 1 + arch/mips/include/asm/mipsregs.h | 1 + arch/mips/kernel/cpu-probe.c | 2 ++ 4 files changed, 7 insertions(+) diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h index 08d1bbe905eb..e686131ff995 100644 --- a/arch/mips/include/asm/cpu-features.h +++ b/arch/mips/include/asm/cpu-features.h @@ -38,6 +38,9 @@ #ifndef cpu_has_maar #define cpu_has_maar (cpu_data[0].options & MIPS_CPU_MAAR) #endif +#ifndef cpu_has_rw_llb +#define cpu_has_rw_llb (cpu_data[0].options & MIPS_CPU_RW_LLB) +#endif /* * For the moment we don't consider R6000 and R8000 so we can assume that diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h index f604523aec3d..15687234d70a 100644 --- a/arch/mips/include/asm/cpu.h +++ b/arch/mips/include/asm/cpu.h @@ -376,6 +376,7 @@ enum cpu_type_enum { #define MIPS_CPU_RIXIEX 0x200000000ull /* CPU has unique exception codes for {Read, Execute}-Inhibit exceptions */ #define MIPS_CPU_MAAR 0x400000000ull /* MAAR(I) registers are present */ #define MIPS_CPU_FRE 0x800000000ull /* FRE & UFE bits implemented */ +#define MIPS_CPU_RW_LLB 0x1000000000ull /* LLADDR/LLB writes are allowed */ /* * CPU ASE encodings diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h index 5e4aef304b02..093cd70e56ec 100644 --- a/arch/mips/include/asm/mipsregs.h +++ b/arch/mips/include/asm/mipsregs.h @@ -653,6 +653,7 @@ #define MIPS_CONF5_NF (_ULCAST_(1) << 0) #define MIPS_CONF5_UFR (_ULCAST_(1) << 2) #define MIPS_CONF5_MRP (_ULCAST_(1) << 3) +#define MIPS_CONF5_LLB (_ULCAST_(1) << 4) #define MIPS_CONF5_MVH (_ULCAST_(1) << 5) #define MIPS_CONF5_FRE (_ULCAST_(1) << 8) #define MIPS_CONF5_UFE (_ULCAST_(1) << 9) diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 1b9488a17f88..81f0aedbba0f 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -514,6 +514,8 @@ static inline unsigned int decode_config5(struct cpuinfo_mips *c) c->options |= MIPS_CPU_EVA; if (config5 & MIPS_CONF5_MRP) c->options |= MIPS_CPU_MAAR; + if (config5 & MIPS_CONF5_LLB) + c->options |= MIPS_CPU_RW_LLB; return config5 & MIPS_CONF_M; } -- 2.39.5