diff options
Diffstat (limited to 'arch/arm64/kernel/entry-common.c')
| -rw-r--r-- | arch/arm64/kernel/entry-common.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 6b2e0c367702..0fc94207e69a 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -355,6 +355,35 @@ static bool cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) } #endif /* CONFIG_ARM64_ERRATUM_1463225 */ +/* + * As per the ABI exit SME streaming mode and clear the SVE state not + * shared with FPSIMD on syscall entry. + */ +static inline void fp_user_discard(void) +{ + /* + * If SME is active then exit streaming mode. If ZA is active + * then flush the SVE registers but leave userspace access to + * both SVE and SME enabled, otherwise disable SME for the + * task and fall through to disabling SVE too. This means + * that after a syscall we never have any streaming mode + * register state to track, if this changes the KVM code will + * need updating. + */ + if (system_supports_sme()) + sme_smstop_sm(); + + if (!system_supports_sve()) + return; + + if (test_thread_flag(TIF_SVE)) { + unsigned int sve_vq_minus_one; + + sve_vq_minus_one = sve_vq_from_vl(task_get_sve_vl(current)) - 1; + sve_flush_live(true, sve_vq_minus_one); + } +} + UNHANDLED(el1t, 64, sync) UNHANDLED(el1t, 64, irq) UNHANDLED(el1t, 64, fiq) @@ -644,6 +673,8 @@ static void noinstr el0_svc(struct pt_regs *regs) { enter_from_user_mode(regs); cortex_a76_erratum_1463225_svc_handler(); + fp_user_discard(); + local_daif_restore(DAIF_PROCCTX); do_el0_svc(regs); exit_to_user_mode(regs); } @@ -783,6 +814,7 @@ static void noinstr el0_svc_compat(struct pt_regs *regs) { enter_from_user_mode(regs); cortex_a76_erratum_1463225_svc_handler(); + local_daif_restore(DAIF_PROCCTX); do_el0_svc_compat(regs); exit_to_user_mode(regs); } |