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>
This commit is contained in:
Kiryl Shutsemau (Meta)
2026-06-29 16:07:16 +01:00
committed by Will Deacon
parent 5686f2bed0
commit 9141eda9ee
3 changed files with 19 additions and 0 deletions

View File

@@ -339,6 +339,18 @@ static void _ipi_unmask_cpu(void *ignored)
sdei_unmask_local_cpu();
}
/*
* 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

View File

@@ -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);

View File

@@ -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)