diff options
| -rw-r--r-- | arch/arm64/include/asm/fpsimd.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 22 |
2 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index b751064bbaaa..b8cf0ea43cc0 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -111,6 +111,8 @@ static inline bool thread_za_enabled(struct thread_struct *thread) return system_supports_sme() && (thread->svcr & SVCR_ZA_MASK); } +extern void task_smstop_sm(struct task_struct *task); + /* Maximum VL that SVE/SME VL-agnostic software can transparently support */ #define VL_ARCH_MAX 0x100 diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index c2603fe8dd24..fe96e018e18c 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -695,6 +695,28 @@ static inline void sve_to_fpsimd(struct task_struct *task) } } +static inline void __fpsimd_zero_vregs(struct user_fpsimd_state *fpsimd) +{ + memset(&fpsimd->vregs, 0, sizeof(fpsimd->vregs)); +} + +/* + * Simulate the effects of an SMSTOP SM instruction. + */ +void task_smstop_sm(struct task_struct *task) +{ + if (!thread_sm_enabled(&task->thread)) + return; + + __fpsimd_zero_vregs(&task->thread.uw.fpsimd_state); + task->thread.uw.fpsimd_state.fpsr = 0x0800009f; + if (system_supports_fpmr()) + task->thread.uw.fpmr = 0; + + task->thread.svcr &= ~SVCR_SM_MASK; + task->thread.fp_type = FP_STATE_FPSIMD; +} + void cpu_enable_fpmr(const struct arm64_cpu_capabilities *__always_unused p) { write_sysreg_s(read_sysreg_s(SYS_SCTLR_EL1) | SCTLR_EL1_EnFPM_MASK, |