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| author | Julien Grall <julien.grall@arm.com> | 2020-08-28 21:11:53 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-09-21 20:06:33 +0300 |
| commit | 9c4b4c701e53183df94f6b9802b63762f0c0e1e3 (patch) | |
| tree | 2e91c9e01c34d0a85c73e18ef31761ab86af5ec0 /arch/arm64 | |
| parent | 1e530f1352a2709d7bcacdb8b6d42c8900ba2c80 (diff) | |
| download | linux-9c4b4c701e53183df94f6b9802b63762f0c0e1e3.tar.xz | |
arm64/sve: Implement a helper to load SVE registers from FPSIMD state
In a follow-up patch, we may save the FPSIMD rather than the full SVE
state when the state has to be zeroed on return to userspace (e.g
during a syscall).
Introduce an helper to load SVE vectors from FPSIMD state and zero the rest
of SVE registers.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20200828181155.17745-7-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/fpsimd.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry-fpsimd.S | 17 |
2 files changed, 19 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 958f642e930d..bec5f14b622a 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -70,6 +70,8 @@ extern void sve_save_state(void *state, u32 *pfpsr); extern void sve_load_state(void const *state, u32 const *pfpsr, unsigned long vq_minus_1); extern void sve_flush_live(void); +extern void sve_load_from_fpsimd_state(struct user_fpsimd_state const *state, + unsigned long vq_minus_1); extern unsigned int sve_get_vl(void); struct arm64_cpu_capabilities; diff --git a/arch/arm64/kernel/entry-fpsimd.S b/arch/arm64/kernel/entry-fpsimd.S index fdf7a5a35c63..2ca395c25448 100644 --- a/arch/arm64/kernel/entry-fpsimd.S +++ b/arch/arm64/kernel/entry-fpsimd.S @@ -48,6 +48,23 @@ SYM_FUNC_START(sve_get_vl) ret SYM_FUNC_END(sve_get_vl) +/* + * Load SVE state from FPSIMD state. + * + * x0 = pointer to struct fpsimd_state + * x1 = VQ - 1 + * + * Each SVE vector will be loaded with the first 128-bits taken from FPSIMD + * and the rest zeroed. All the other SVE registers will be zeroed. + */ +SYM_FUNC_START(sve_load_from_fpsimd_state) + sve_load_vq x1, x2, x3 + fpsimd_restore x0, 8 + _for n, 0, 15, _sve_pfalse \n + _sve_wrffr 0 + ret +SYM_FUNC_END(sve_load_from_fpsimd_state) + /* Zero all SVE registers but the first 128-bits of each vector */ SYM_FUNC_START(sve_flush_live) sve_flush |