diff options
| author | Mark Brown <broonie@kernel.org> | 2023-01-16 16:04:45 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2023-01-20 12:23:06 +0000 |
| commit | 95fcec713259d440626526ed96ff5d3bac6179ea (patch) | |
| tree | 6bacccf7c516bd59f045725f0615036b20d00eb9 /arch/arm64/kernel | |
| parent | d6138b4adc70729404efeb0133bc9f6e9ad78d03 (diff) | |
arm64/sme: Implement context switching for ZT0
When the system supports SME2 the ZT0 register must be context switched as
part of the floating point state. This register is stored immediately
after ZA in memory and is only accessible when PSTATE.ZA is set so we
handle it in the same functions we use to save and restore ZA.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221208-arm64-sme2-v4-10-f2fa0aef982f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/entry-fpsimd.S | 30 | ||||
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 6 |
2 files changed, 24 insertions, 12 deletions
diff --git a/arch/arm64/kernel/entry-fpsimd.S b/arch/arm64/kernel/entry-fpsimd.S index 229436f33df5..6325db1a2179 100644 --- a/arch/arm64/kernel/entry-fpsimd.S +++ b/arch/arm64/kernel/entry-fpsimd.S @@ -100,25 +100,35 @@ SYM_FUNC_START(sme_set_vq) SYM_FUNC_END(sme_set_vq) /* - * Save the SME state + * Save the ZA and ZT state * * x0 - pointer to buffer for state + * x1 - number of ZT registers to save */ -SYM_FUNC_START(za_save_state) - _sme_rdsvl 1, 1 // x1 = VL/8 - sme_save_za 0, x1, 12 +SYM_FUNC_START(sme_save_state) + _sme_rdsvl 2, 1 // x2 = VL/8 + sme_save_za 0, x2, 12 // Leaves x0 pointing to the end of ZA + + cbz x1, 1f + _str_zt 0 +1: ret -SYM_FUNC_END(za_save_state) +SYM_FUNC_END(sme_save_state) /* - * Load the SME state + * Load the ZA and ZT state * * x0 - pointer to buffer for state + * x1 - number of ZT registers to save */ -SYM_FUNC_START(za_load_state) - _sme_rdsvl 1, 1 // x1 = VL/8 - sme_load_za 0, x1, 12 +SYM_FUNC_START(sme_load_state) + _sme_rdsvl 2, 1 // x2 = VL/8 + sme_load_za 0, x2, 12 // Leaves x0 pointing to the end of ZA + + cbz x1, 1f + _ldr_zt 0 +1: ret -SYM_FUNC_END(za_load_state) +SYM_FUNC_END(sme_load_state) #endif /* CONFIG_ARM64_SME */ diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 717ae4aaa021..cec8b43e7888 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -429,7 +429,8 @@ static void task_fpsimd_load(void) write_sysreg_s(current->thread.svcr, SYS_SVCR); if (thread_za_enabled(¤t->thread)) - za_load_state(current->thread.sme_state); + sme_load_state(current->thread.sme_state, + system_supports_sme2()); if (thread_sm_enabled(¤t->thread)) restore_ffr = system_supports_fa64(); @@ -490,7 +491,8 @@ static void fpsimd_save(void) *svcr = read_sysreg_s(SYS_SVCR); if (*svcr & SVCR_ZA_MASK) - za_save_state(last->sme_state); + sme_save_state(last->sme_state, + system_supports_sme2()); /* If we are in streaming mode override regular SVE. */ if (*svcr & SVCR_SM_MASK) { |