diff options
| author | Mark Brown <broonie@kernel.org> | 2021-10-19 18:22:09 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-10-21 10:18:17 +0100 |
| commit | 9f5848665788a0f07bc175cb2cdd06d367b7556e (patch) | |
| tree | 1dac56919c1e02594e369ce832f8c4ce1447a136 /arch/arm64/include | |
| parent | 12cc2352bfb34dbdf97e51b006c32a8bd0d13bcb (diff) | |
arm64/sve: Make access to FFR optional
SME introduces streaming SVE mode in which FFR is not present and the
instructions for accessing it UNDEF. In preparation for handling this
update the low level SVE state access functions to take a flag specifying
if FFR should be handled. When saving the register state we store a zero
for FFR to guard against uninitialized data being read. No behaviour change
should be introduced by this patch.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-5-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/fpsimd.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/fpsimdmacros.h | 20 |
2 files changed, 17 insertions, 9 deletions
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 917ecc301d1d..7f8a44a9a5e6 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -65,10 +65,10 @@ static inline void *sve_pffr(struct thread_struct *thread) return (char *)thread->sve_state + sve_ffr_offset(thread->sve_vl); } -extern void sve_save_state(void *state, u32 *pfpsr); +extern void sve_save_state(void *state, u32 *pfpsr, int save_ffr); extern void sve_load_state(void const *state, u32 const *pfpsr, - unsigned long vq_minus_1); -extern void sve_flush_live(unsigned long vq_minus_1); + int restore_ffr, unsigned long vq_minus_1); +extern void sve_flush_live(bool flush_ffr, unsigned long vq_minus_1); extern unsigned int sve_get_vl(void); extern void sve_set_vq(unsigned long vq_minus_1); diff --git a/arch/arm64/include/asm/fpsimdmacros.h b/arch/arm64/include/asm/fpsimdmacros.h index 00a2c0b69c2b..e5ffd8b265b6 100644 --- a/arch/arm64/include/asm/fpsimdmacros.h +++ b/arch/arm64/include/asm/fpsimdmacros.h @@ -217,28 +217,36 @@ .macro sve_flush_z _for n, 0, 31, _sve_flush_z \n .endm -.macro sve_flush_p_ffr +.macro sve_flush_p _for n, 0, 15, _sve_pfalse \n +.endm +.macro sve_flush_ffr _sve_wrffr 0 .endm -.macro sve_save nxbase, xpfpsr, nxtmp +.macro sve_save nxbase, xpfpsr, save_ffr, nxtmp _for n, 0, 31, _sve_str_v \n, \nxbase, \n - 34 _for n, 0, 15, _sve_str_p \n, \nxbase, \n - 16 + cbz \save_ffr, 921f _sve_rdffr 0 _sve_str_p 0, \nxbase _sve_ldr_p 0, \nxbase, -16 - + b 922f +921: + str xzr, [x\nxbase] // Zero out FFR +922: mrs x\nxtmp, fpsr str w\nxtmp, [\xpfpsr] mrs x\nxtmp, fpcr str w\nxtmp, [\xpfpsr, #4] .endm -.macro __sve_load nxbase, xpfpsr, nxtmp +.macro __sve_load nxbase, xpfpsr, restore_ffr, nxtmp _for n, 0, 31, _sve_ldr_v \n, \nxbase, \n - 34 + cbz \restore_ffr, 921f _sve_ldr_p 0, \nxbase _sve_wrffr 0 +921: _for n, 0, 15, _sve_ldr_p \n, \nxbase, \n - 16 ldr w\nxtmp, [\xpfpsr] @@ -247,7 +255,7 @@ msr fpcr, x\nxtmp .endm -.macro sve_load nxbase, xpfpsr, xvqminus1, nxtmp, xtmp2 +.macro sve_load nxbase, xpfpsr, restore_ffr, xvqminus1, nxtmp, xtmp2 sve_load_vq \xvqminus1, x\nxtmp, \xtmp2 - __sve_load \nxbase, \xpfpsr, \nxtmp + __sve_load \nxbase, \xpfpsr, \restore_ffr, \nxtmp .endm |