| Message ID | 1503065517-7920-2-git-send-email-gengdongjiu@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 18 Aug 2017 22:11:51 +0800 Dongjiu Geng <gengdongjiu@huawei.com> wrote: > From: Xie XiuQi <xiexiuqi@huawei.com> > > ARM's v8.2 Extentions add support for Reliability, Availability and > Serviceability (RAS). On CPUs with these extensions system software extensions, system software > can use additional barriers to isolate errors and determine if faults > are pending. > > Add cpufeature detection and a barrier in the context-switch code. > There is no need to use alternatives for this as CPUs that don't > support this feature will treat the instruction as a nop. > > Platform level RAS support may require additional firmware support. > > Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com> > [Rebased, added esb and config option, reworded commit message] > Signed-off-by: James Morse <james.morse@arm.com> > --- > arch/arm64/Kconfig | 16 ++++++++++++++++ > arch/arm64/include/asm/barrier.h | 1 + > arch/arm64/include/asm/cpucaps.h | 3 ++- > arch/arm64/include/asm/sysreg.h | 2 ++ > arch/arm64/kernel/cpufeature.c | 13 +++++++++++++ > arch/arm64/kernel/process.c | 3 +++ > 6 files changed, 37 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index dfd908630631..4d87aa963d83 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -960,6 +960,22 @@ config ARM64_UAO > regular load/store instructions if the cpu does not implement the > feature. > > +config ARM64_RAS_EXTN > + bool "Enable support for RAS CPU Extensions" > + default y > + help > + CPUs that support the Reliability, Availability and Serviceability > + (RAS) Extensions, part of ARMv8.2 are able to track faults and > + errors, classify them and report them to software. > + > + On CPUs with these extensions system software can use additional > + barriers to determine if faults are pending and read the > + classification from a new set of registers. > + > + Selecting this feature will allow the kernel to use these barriers > + and access the new registers if the system supports the extension. > + Platform RAS features may additionally depend on firmware support. > + > endmenu > > config ARM64_MODULE_CMODEL_LARGE > diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h > index 0fe7e43b7fbc..8b0a0eb67625 100644 > --- a/arch/arm64/include/asm/barrier.h > +++ b/arch/arm64/include/asm/barrier.h > @@ -30,6 +30,7 @@ > #define isb() asm volatile("isb" : : : "memory") > #define dmb(opt) asm volatile("dmb " #opt : : : "memory") > #define dsb(opt) asm volatile("dsb " #opt : : : "memory") > +#define esb() asm volatile("hint #16" : : : "memory") > > #define mb() dsb(sy) > #define rmb() dsb(ld) > diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h > index 8d2272c6822c..f93bf77f1f74 100644 > --- a/arch/arm64/include/asm/cpucaps.h > +++ b/arch/arm64/include/asm/cpucaps.h > @@ -39,7 +39,8 @@ > #define ARM64_WORKAROUND_QCOM_FALKOR_E1003 18 > #define ARM64_WORKAROUND_858921 19 > #define ARM64_WORKAROUND_CAVIUM_30115 20 > +#define ARM64_HAS_RAS_EXTN 21 > > -#define ARM64_NCAPS 21 > +#define ARM64_NCAPS 22 > > #endif /* __ASM_CPUCAPS_H */ > diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h > index 248339e4aaf5..35b786b43ee4 100644 > --- a/arch/arm64/include/asm/sysreg.h > +++ b/arch/arm64/include/asm/sysreg.h > @@ -331,6 +331,7 @@ > #define ID_AA64ISAR1_JSCVT_SHIFT 12 > > /* id_aa64pfr0 */ > +#define ID_AA64PFR0_RAS_SHIFT 28 > #define ID_AA64PFR0_GIC_SHIFT 24 > #define ID_AA64PFR0_ASIMD_SHIFT 20 > #define ID_AA64PFR0_FP_SHIFT 16 > @@ -339,6 +340,7 @@ > #define ID_AA64PFR0_EL1_SHIFT 4 > #define ID_AA64PFR0_EL0_SHIFT 0 > > +#define ID_AA64PFR0_RAS_V1 0x1 > #define ID_AA64PFR0_FP_NI 0xf > #define ID_AA64PFR0_FP_SUPPORTED 0x0 > #define ID_AA64PFR0_ASIMD_NI 0xf > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 9f9e0064c8c1..a807ab55ee10 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -124,6 +124,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar1[] = { > }; > > static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { > + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64PFR0_RAS_SHIFT, 4, 0), > ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64PFR0_GIC_SHIFT, 4, 0), > S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI), > S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI), > @@ -888,6 +889,18 @@ static const struct arm64_cpu_capabilities arm64_features[] = { > .min_field_value = 0, > .matches = has_no_fpsimd, > }, > +#ifdef CONFIG_ARM64_RAS_EXTN > + { > + .desc = "RAS Extension Support", > + .capability = ARM64_HAS_RAS_EXTN, > + .def_scope = SCOPE_SYSTEM, > + .matches = has_cpuid_feature, > + .sys_reg = SYS_ID_AA64PFR0_EL1, > + .sign = FTR_UNSIGNED, > + .field_pos = ID_AA64PFR0_RAS_SHIFT, > + .min_field_value = ID_AA64PFR0_RAS_V1, > + }, > +#endif /* CONFIG_ARM64_RAS_EXTN */ > {}, > }; > > diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c > index 659ae8094ed5..2def5ce75867 100644 > --- a/arch/arm64/kernel/process.c > +++ b/arch/arm64/kernel/process.c > @@ -363,6 +363,9 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, > */ > dsb(ish); > > + /* Deliver any pending SError from prev */ > + esb(); > + > /* the actual thread switch */ > last = cpu_switch_to(prev, next); >
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index dfd908630631..4d87aa963d83 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -960,6 +960,22 @@ config ARM64_UAO regular load/store instructions if the cpu does not implement the feature. +config ARM64_RAS_EXTN + bool "Enable support for RAS CPU Extensions" + default y + help + CPUs that support the Reliability, Availability and Serviceability + (RAS) Extensions, part of ARMv8.2 are able to track faults and + errors, classify them and report them to software. + + On CPUs with these extensions system software can use additional + barriers to determine if faults are pending and read the + classification from a new set of registers. + + Selecting this feature will allow the kernel to use these barriers + and access the new registers if the system supports the extension. + Platform RAS features may additionally depend on firmware support. + endmenu config ARM64_MODULE_CMODEL_LARGE diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h index 0fe7e43b7fbc..8b0a0eb67625 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -30,6 +30,7 @@ #define isb() asm volatile("isb" : : : "memory") #define dmb(opt) asm volatile("dmb " #opt : : : "memory") #define dsb(opt) asm volatile("dsb " #opt : : : "memory") +#define esb() asm volatile("hint #16" : : : "memory") #define mb() dsb(sy) #define rmb() dsb(ld) diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index 8d2272c6822c..f93bf77f1f74 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -39,7 +39,8 @@ #define ARM64_WORKAROUND_QCOM_FALKOR_E1003 18 #define ARM64_WORKAROUND_858921 19 #define ARM64_WORKAROUND_CAVIUM_30115 20 +#define ARM64_HAS_RAS_EXTN 21 -#define ARM64_NCAPS 21 +#define ARM64_NCAPS 22 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 248339e4aaf5..35b786b43ee4 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -331,6 +331,7 @@ #define ID_AA64ISAR1_JSCVT_SHIFT 12 /* id_aa64pfr0 */ +#define ID_AA64PFR0_RAS_SHIFT 28 #define ID_AA64PFR0_GIC_SHIFT 24 #define ID_AA64PFR0_ASIMD_SHIFT 20 #define ID_AA64PFR0_FP_SHIFT 16 @@ -339,6 +340,7 @@ #define ID_AA64PFR0_EL1_SHIFT 4 #define ID_AA64PFR0_EL0_SHIFT 0 +#define ID_AA64PFR0_RAS_V1 0x1 #define ID_AA64PFR0_FP_NI 0xf #define ID_AA64PFR0_FP_SUPPORTED 0x0 #define ID_AA64PFR0_ASIMD_NI 0xf diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 9f9e0064c8c1..a807ab55ee10 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -124,6 +124,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar1[] = { }; static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64PFR0_RAS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64PFR0_GIC_SHIFT, 4, 0), S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI), S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI), @@ -888,6 +889,18 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .min_field_value = 0, .matches = has_no_fpsimd, }, +#ifdef CONFIG_ARM64_RAS_EXTN + { + .desc = "RAS Extension Support", + .capability = ARM64_HAS_RAS_EXTN, + .def_scope = SCOPE_SYSTEM, + .matches = has_cpuid_feature, + .sys_reg = SYS_ID_AA64PFR0_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64PFR0_RAS_SHIFT, + .min_field_value = ID_AA64PFR0_RAS_V1, + }, +#endif /* CONFIG_ARM64_RAS_EXTN */ {}, }; diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 659ae8094ed5..2def5ce75867 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -363,6 +363,9 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, */ dsb(ish); + /* Deliver any pending SError from prev */ + esb(); + /* the actual thread switch */ last = cpu_switch_to(prev, next);