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| author |  Mark Rutland <mark.rutland@arm.com>
| 2019-10-25 17:42:12 +0100 |
|---|---|---|
| committer |  Catalin Marinas <catalin.marinas@arm.com>
| 2019-10-28 11:22:43 +0000 |
| commit | 51077e03b8cef2a24d6582b8c54b718fced6878c (patch) | |
| tree | 7644c7010684bf47a1e93362e73ffcd6cc00827b /arch/arm64/include/asm/daifflags.h | |
| parent | arm64: Add prototypes for functions called by entry.S (diff) | |
| download | linux-51077e03b8cef2a24d6582b8c54b718fced6878c.tar.gz linux-51077e03b8cef2a24d6582b8c54b718fced6878c.tar.bz2 linux-51077e03b8cef2a24d6582b8c54b718fced6878c.zip | |
arm64: add local_daif_inherit()
Some synchronous exceptions can be taken from a number of contexts,
e.g. where IRQs may or may not be masked. In the entry assembly for
these exceptions, we use the inherit_daif assembly macro to ensure
that we only mask those exceptions which were masked when the exception
was taken.
So that we can do the same from C code, this patch adds a new
local_daif_inherit() function, following the existing local_daif_*()
naming scheme.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[moved away from local_daif_restore()]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/daifflags.h')
| -rw-r--r-- | arch/arm64/include/asm/daifflags.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h index 063c964af705..9207cd5aa39e 100644 --- a/arch/arm64/include/asm/daifflags.h +++ b/arch/arm64/include/asm/daifflags.h @@ -9,6 +9,7 @@ #include <asm/arch_gicv3.h> #include <asm/cpufeature.h> +#include <asm/ptrace.h> #define DAIF_PROCCTX 0 #define DAIF_PROCCTX_NOIRQ PSR_I_BIT @@ -109,4 +110,19 @@ static inline void local_daif_restore(unsigned long flags) trace_hardirqs_off(); } +/* + * Called by synchronous exception handlers to restore the DAIF bits that were + * modified by taking an exception. + */ +static inline void local_daif_inherit(struct pt_regs *regs) +{ + unsigned long flags = regs->pstate & DAIF_MASK; + + /* + * We can't use local_daif_restore(regs->pstate) here as + * system_has_prio_mask_debugging() won't restore the I bit if it can + * use the pmr instead. + */ + write_sysreg(flags, daif); +} #endif |