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| author | Kiryl Shutsemau (Meta) <kas@kernel.org> | 2026-06-29 16:07:16 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2026-08-02 09:21:06 +0000 |
| commit | 9141eda9eec76b538bb64e89185034ec61d341ca (patch) | |
| tree | d83236a46f28fc1b4834bc1ac73860b23f298176 | |
| parent | 5686f2bed02d98d03e3f38f4b5569804510fba31 (diff) | |
| download | linux-next-9141eda9eec76b538bb64e89185034ec61d341ca.tar.gz linux-next-9141eda9eec76b538bb64e89185034ec61d341ca.zip | |
firmware: arm_sdei: add SDEI_EVENT_SIGNAL support
Add sdei_event_signal(), a thin wrapper over the SDEI_EVENT_SIGNAL call
(DEN0054) that makes the software-signalled event (event 0) pending on a
target PE -- delivered NMI-like even when that PE has interrupts masked.
It takes no locks, so it is safe to call from NMI / crash context.
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Yin Fengwei <fengwei_yin@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | drivers/firmware/arm_sdei.c | 12 | ||||
| -rw-r--r-- | include/linux/arm_sdei.h | 6 | ||||
| -rw-r--r-- | include/uapi/linux/arm_sdei.h | 1 |
3 files changed, 19 insertions, 0 deletions
diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c index c161cf263547..e8dd2f0f3919 100644 --- a/drivers/firmware/arm_sdei.c +++ b/drivers/firmware/arm_sdei.c @@ -340,6 +340,18 @@ static void _ipi_unmask_cpu(void *ignored) } /* + * Signal the software-signalled event (event 0) to @mpidr. Does nothing + * but the SMC -- no locks, no event lookup -- so it is safe from NMI / + * crash context (e.g. the cross-CPU NMI service). + */ +int sdei_event_signal(u32 event_num, u64 mpidr) +{ + return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_SIGNAL, event_num, + mpidr, 0, 0, 0, NULL); +} +NOKPROBE_SYMBOL(sdei_event_signal); + +/* * Was SDEI firmware probed and is it usable? Lets optional consumers skip * registering an event -- and the warning a failed registration emits -- on * systems with no SDEI. diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h index b07113eeeff7..b9dc21c241be 100644 --- a/include/linux/arm_sdei.h +++ b/include/linux/arm_sdei.h @@ -37,6 +37,12 @@ int sdei_event_unregister(u32 event_num); int sdei_event_enable(u32 event_num); int sdei_event_disable(u32 event_num); +/* + * Signal the software-signalled event (event 0) to another PE, NMI-like. + * @mpidr is the target's MPIDR affinity. + */ +int sdei_event_signal(u32 event_num, u64 mpidr); + /* Was SDEI firmware probed and usable? */ bool sdei_is_present(void); diff --git a/include/uapi/linux/arm_sdei.h b/include/uapi/linux/arm_sdei.h index af0630ba5437..22eb61612673 100644 --- a/include/uapi/linux/arm_sdei.h +++ b/include/uapi/linux/arm_sdei.h @@ -22,6 +22,7 @@ #define SDEI_1_0_FN_SDEI_PE_UNMASK SDEI_1_0_FN(0x0C) #define SDEI_1_0_FN_SDEI_INTERRUPT_BIND SDEI_1_0_FN(0x0D) #define SDEI_1_0_FN_SDEI_INTERRUPT_RELEASE SDEI_1_0_FN(0x0E) +#define SDEI_1_0_FN_SDEI_EVENT_SIGNAL SDEI_1_0_FN(0x0F) #define SDEI_1_0_FN_SDEI_PRIVATE_RESET SDEI_1_0_FN(0x11) #define SDEI_1_0_FN_SDEI_SHARED_RESET SDEI_1_0_FN(0x12) |