From e06a1548f3043febb658b58ec5ccbc7d03a785af Mon Sep 17 00:00:00 2001 From: James Hogan Date: Wed, 11 May 2016 13:50:51 +0100 Subject: [PATCH] MIPS: Add defs & probing of BadInstr[P] registers The optional CP0_BadInstr and CP0_BadInstrP registers are written with the encoding of the instruction that caused a synchronous exception to occur, and the prior branch instruction if in a delay slot. These will be useful for instruction emulation in KVM, and especially for VZ support where reading guest virtual memory is a bit more awkward. Add CPU option numbers and cpu_has_* definitions to indicate the presence of each registers, and add code to probe for them using bits in the CP0_Config3 register. [ralf@linux-mips.org: resolve merge conflict.] Signed-off-by: James Hogan Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13224/ Signed-off-by: Ralf Baechle --- arch/mips/include/asm/cpu-features.h | 8 ++++++++ arch/mips/include/asm/cpu.h | 2 ++ arch/mips/include/asm/mipsregs.h | 3 +++ arch/mips/kernel/cpu-probe.c | 4 ++++ 4 files changed, 17 insertions(+) diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h index 676a37b..5d82b01 100644 --- a/arch/mips/include/asm/cpu-features.h +++ b/arch/mips/include/asm/cpu-features.h @@ -442,4 +442,12 @@ # define cpu_has_ebase_wg (cpu_data[0].options & MIPS_CPU_EBASE_WG) #endif +#ifndef cpu_has_badinstr +# define cpu_has_badinstr (cpu_data[0].options & MIPS_CPU_BADINSTR) +#endif + +#ifndef cpu_has_badinstrp +# define cpu_has_badinstrp (cpu_data[0].options & MIPS_CPU_BADINSTRP) +#endif + #endif /* __ASM_CPU_FEATURES_H */ diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h index 3108d9b..0cf90d67 100644 --- a/arch/mips/include/asm/cpu.h +++ b/arch/mips/include/asm/cpu.h @@ -405,6 +405,8 @@ enum cpu_type_enum { #define MIPS_CPU_LDPTE MBIT_ULL(41) /* CPU has ldpte/lddir instructions */ #define MIPS_CPU_MVH MBIT_ULL(42) /* CPU supports MFHC0/MTHC0 */ #define MIPS_CPU_EBASE_WG MBIT_ULL(43) /* CPU has EBase.WG */ +#define MIPS_CPU_BADINSTR MBIT_ULL(44) /* CPU has BadInstr register */ +#define MIPS_CPU_BADINSTRP MBIT_ULL(45) /* CPU has BadInstrP register */ /* * CPU ASE encodings diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h index 4e8ad9d..b1f8f84 100644 --- a/arch/mips/include/asm/mipsregs.h +++ b/arch/mips/include/asm/mipsregs.h @@ -1248,6 +1248,9 @@ do { \ #define read_c0_badvaddr() __read_ulong_c0_register($8, 0) #define write_c0_badvaddr(val) __write_ulong_c0_register($8, 0, val) +#define read_c0_badinstr() __read_32bit_c0_register($8, 1) +#define read_c0_badinstrp() __read_32bit_c0_register($8, 2) + #define read_c0_count() __read_32bit_c0_register($9, 0) #define write_c0_count(val) __write_32bit_c0_register($9, 0, val) diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 6a1a7da..8e54d51 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -714,6 +714,10 @@ static inline unsigned int decode_config3(struct cpuinfo_mips *c) c->ases |= MIPS_ASE_VZ; if (config3 & MIPS_CONF3_SC) c->options |= MIPS_CPU_SEGMENTS; + if (config3 & MIPS_CONF3_BI) + c->options |= MIPS_CPU_BADINSTR; + if (config3 & MIPS_CONF3_BP) + c->options |= MIPS_CPU_BADINSTRP; if (config3 & MIPS_CONF3_MSA) c->ases |= MIPS_ASE_MSA; if (config3 & MIPS_CONF3_PW) { -- 2.7.4