diff options
| author | Dave Martin <Dave.Martin@arm.com> | 2017-08-03 17:23:22 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2017-08-04 15:00:54 +0100 |
| commit | 4328825d4fdc185d365d8e858cace8b324198a70 (patch) | |
| tree | 1f4b0a11ca937b4d1f2f75906ba1886337d4e3f1 /arch/arm64/include/asm/fpsimd.h | |
| parent | 504641859e5c616210c0894149e09fb6928e398f (diff) | |
arm64: neon: Allow EFI runtime services to use FPSIMD in irq context
In order to be able to cope with kernel-mode NEON being unavailable
in hardirq/nmi context and non-nestable, we need special handling
for EFI runtime service calls that may be made during an interrupt
that interrupted a kernel_neon_begin()..._end() block. This will
occur if the kernel tries to write diagnostic data to EFI
persistent storage during a panic triggered by an NMI for example.
EFI runtime services specify an ABI that clobbers the FPSIMD state,
rather than being able to use it optionally as an accelerator.
This means that EFI is really a special case and can be handled
specially.
To enable EFI calls from interrupts, this patch creates dedicated
__efi_fpsimd_{begin,end}() helpers solely for this purpose, which
save/restore to a separate percpu buffer if called in a context
where kernel_neon_begin() is not usable.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/fpsimd.h')
| -rw-r--r-- | arch/arm64/include/asm/fpsimd.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 50f559f574fe..5155f21e15e3 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -81,6 +81,10 @@ extern void fpsimd_save_partial_state(struct fpsimd_partial_state *state, u32 num_regs); extern void fpsimd_load_partial_state(struct fpsimd_partial_state *state); +/* For use by EFI runtime services calls only */ +extern void __efi_fpsimd_begin(void); +extern void __efi_fpsimd_end(void); + #endif #endif |