| Message ID | 20190512165032.19942-1-shawn@git.icu (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | powerpc: add simd.h implementation specific to PowerPC | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch next (8150a153c013aa2dd1ffae43370b89ac1347a7fb) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 15 lines checked |
diff --git a/arch/powerpc/include/asm/simd.h b/arch/powerpc/include/asm/simd.h new file mode 100644 index 000000000..b3fecb95a --- /dev/null +++ b/arch/powerpc/include/asm/simd.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ + +#include <asm/cpu_has_feature.h> + +/* + * may_use_simd - whether it is allowable at this time to issue SIMD + * instructions or access the SIMD register file + * + * As documented in Chapter 6.2.1 Machine Status Save/Restore Registers + * of Power ISA (2.07 and 3.0), all registers are saved/restored in an interrupt. + */ +static inline bool may_use_simd(void) +{ + return !cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE); +}
It is safe to do SIMD in an interrupt on PowerPC. Only disable when there is no SIMD available (and this is a static branch). Tested and works with the WireGuard (Zinc) patch I wrote that needs this. Also improves performance of the crypto subsystem that checks this. Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=203571 Signed-off-by: Shawn Landden <shawn@git.icu> --- arch/powerpc/include/asm/simd.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 arch/powerpc/include/asm/simd.h