On 15/01/18 19:38, James Morse wrote:
KVM would like to consume any pending SError (or RAS error) after guest
exit. Today it has to unmask SError and use dsb+isb to synchronise the
CPU. With the RAS extensions we can use ESB to synchronise any pending
SError.
Add the necessary macros to allow DISR to be read and converted to an
ESR.
We clear the DISR register when we enable the RAS cpufeature, and the
kernel has not executed any ESB instructions. Any value we find in DISR
must have belonged to firmware. Executing an ESB instruction is the
only way to update DISR, so we can expect firmware to have handled
any deferred SError. By the same logic we clear DISR in the idle path.
Signed-off-by: James Morse <james.morse@xxxxxxx>
Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
James,
Looks fine to me. minor nit below
#endif /* __ASM_EXCEPTION_H */
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index 023cacb946c3..cee4ae25a5d1 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -216,6 +216,7 @@ static inline void spin_lock_prefetch(const void *ptr)
int cpu_enable_pan(void *__unused);
int cpu_enable_cache_maint_trap(void *__unused);
+int cpu_clear_disr(void *__unused);
/* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
#define SVE_SET_VL(arg) sve_set_current_vl(arg)
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 1281bc8263c2..115b89aeec00 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -279,6 +279,7 @@
#define SYS_AMAIR_EL1 sys_reg(3, 0, 10, 3, 0)
#define SYS_VBAR_EL1 sys_reg(3, 0, 12, 0, 0)
+#define SYS_DISR_EL1 sys_reg(3, 0, 12, 1, 1)
minor nit: additional white space ^^^
With that fixed,
Reviewed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
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