Hi XiuQi, On 2017/3/30 18:31, Xie XiuQi wrote: > Error Synchronization Barrier (ESB; part of the ARMv8.2 Extensions) > is used to synchronize Unrecoverable errors. That is, containable errors > architecturally consumed by the PE and not silently propagated. > > With ESB it is generally possible to isolate an unrecoverable error > between two ESB instructions. So, it's possible to recovery from > unrecoverable errors reported by asynchronous SError interrupt. > > If ARMv8.2 RAS Extension is not support, ESB is treated as a NOP. > > Signed-off-by: Xie XiuQi <xiexiuqi@xxxxxxxxxx> > Signed-off-by: Wang Xiongfeng <wangxiongfengi2@xxxxxxxxxx> > --- > arch/arm64/Kconfig | 16 ++++++++++ > arch/arm64/include/asm/esr.h | 14 +++++++++ > arch/arm64/kernel/entry.S | 70 ++++++++++++++++++++++++++++++++++++++++++-- > arch/arm64/kernel/traps.c | 54 ++++++++++++++++++++++++++++++++-- > 4 files changed, 150 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 859a90e..7402175 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -911,6 +911,22 @@ endmenu > > menu "ARMv8.2 architectural features" > > +config ARM64_ESB > + bool "Enable support for Error Synchronization Barrier (ESB)" > + default n > + help > + Error Synchronization Barrier (ESB; part of the ARMv8.2 Extensions) > + is used to synchronize Unrecoverable errors. That is, containable errors > + architecturally consumed by the PE and not silently propagated. > + > + Without ESB it is not generally possible to isolate an Unrecoverable > + error because it is not known which instruction generated the error. > + > + Selecting this option allows inject esb instruction before the exception > + change. If ARMv8.2 RAS Extension is not support, ESB is treated as a NOP. > + > + Note that ESB instruction can introduce slight overhead, so say N if unsure. > + > config ARM64_UAO > bool "Enable support for User Access Override (UAO)" > default y > diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h > index f20c64a..22f9c90 100644 > --- a/arch/arm64/include/asm/esr.h > +++ b/arch/arm64/include/asm/esr.h > @@ -106,6 +106,20 @@ > #define ESR_ELx_AR (UL(1) << 14) > #define ESR_ELx_CM (UL(1) << 8) > > +#define ESR_Elx_DFSC_SEI (0x11) > + > +#define ESR_ELx_AET_SHIFT (10) > +#define ESR_ELx_AET_MAX (7) > +#define ESR_ELx_AET_MASK (UL(7) << ESR_ELx_AET_SHIFT) > +#define ESR_ELx_AET(esr) (((esr) & ESR_ELx_AET_MASK) >> ESR_ELx_AET_SHIFT) > + > +#define ESR_ELx_AET_UC (0) > +#define ESR_ELx_AET_UEU (1) > +#define ESR_ELx_AET_UEO (2) > +#define ESR_ELx_AET_UER (3) > +#define ESR_ELx_AET_CE (6) > + > + > /* ISS field definitions for exceptions taken in to Hyp */ > #define ESR_ELx_CV (UL(1) << 24) > #define ESR_ELx_COND_SHIFT (20) > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index 43512d4..d8a7306 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -69,7 +69,14 @@ > #define BAD_FIQ 2 > #define BAD_ERROR 3 > > + .arch_extension ras > + > .macro kernel_entry, el, regsize = 64 because we also want to take SEI exception in kernel space, we may need to unmask SEI in kernel_entry. > +#ifdef CONFIG_ARM64_ESB > + .if \el == 0 > + esb > + .endif > +#endif > sub sp, sp, #S_FRAME_SIZE > .if \regsize == 32 > mov w0, w0 // zero upper 32 bits of x0 > @@ -208,6 +215,7 @@ alternative_else_nop_endif > #endif > > .if \el == 0 > + msr daifset, #0xF // Set flags > ldr x23, [sp, #S_SP] // load return stack pointer > msr sp_el0, x23 > #ifdef CONFIG_ARM64_ERRATUM_845719 > @@ -226,6 +234,15 @@ alternative_else_nop_endif > > msr elr_el1, x21 // set up the return data > msr spsr_el1, x22 > + > +#ifdef CONFIG_ARM64_ESB > + .if \el == 0 > + esb // Error Synchronization Barrier > + mrs x21, disr_el1 // Check for deferred error > + tbnz x21, #31, el1_sei > + .endif > +#endif > + > ldp x0, x1, [sp, #16 * 0] > ldp x2, x3, [sp, #16 * 1] > ldp x4, x5, [sp, #16 * 2] > @@ -318,7 +335,7 @@ ENTRY(vectors) > ventry el1_sync_invalid // Synchronous EL1t > ventry el1_irq_invalid // IRQ EL1t > ventry el1_fiq_invalid // FIQ EL1t > - ventry el1_error_invalid // Error EL1t > + ventry el1_error // Error EL1t > > ventry el1_sync // Synchronous EL1h > ventry el1_irq // IRQ EL1h > @@ -328,7 +345,7 @@ ENTRY(vectors) > ventry el0_sync // Synchronous 64-bit EL0 > ventry el0_irq // IRQ 64-bit EL0 > ventry el0_fiq_invalid // FIQ 64-bit EL0 > - ventry el0_error_invalid // Error 64-bit EL0 > + ventry el0_error // Error 64-bit EL0 for the situation 'Current EL with SPx', we also need to change the sError vector to el1_error. > > #ifdef CONFIG_COMPAT > ventry el0_sync_compat // Synchronous 32-bit EL0 > @@ -508,12 +525,31 @@ el1_preempt: > ret x24 > #endif > > + .align 6 > +el1_error: > + kernel_entry 1 > +el1_sei: > + /* > + * asynchronous SError interrupt from kernel > + */ > + mov x0, sp > + mrs x1, esr_el1 > + mov x2, #1 // exception level of SEI generated > + b do_sei > +ENDPROC(el1_error) > + > + Thanks, Wang Xiongfeng
