diff options
| author | James Morse <james.morse@arm.com> | 2020-05-01 17:45:43 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-01 13:18:02 +0200 |
| commit | af02933d59bd1621a48d8b0b331cca9e530ba14b (patch) | |
| tree | eca9acb6d6b1ae447e0fcd10897ec274e8778d21 /arch/arm64/mm | |
| parent | 502bd98a8e279a7645d580724a45132b6039aa1b (diff) | |
arm64: acpi: Make apei_claim_sea() synchronise with APEI's irq work
[ Upstream commit 8fcc4ae6faf8b455eeef00bc9ae70744e3b0f462 ]
APEI is unable to do all of its error handling work in nmi-context, so
it defers non-fatal work onto the irq_work queue. arch_irq_work_raise()
sends an IPI to the calling cpu, but this is not guaranteed to be taken
before returning to user-space.
Unless the exception interrupted a context with irqs-masked,
irq_work_run() can run immediately. Otherwise return -EINPROGRESS to
indicate ghes_notify_sea() found some work to do, but it hasn't
finished yet.
With this apei_claim_sea() returning '0' means this external-abort was
also notification of a firmware-first RAS error, and that APEI has
processed the CPER records.
Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: Tyler Baicar <baicar@os.amperecomputing.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/arm64/mm')
| -rw-r--r-- | arch/arm64/mm/fault.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index d26e6cd28953..2a7339aeb1ad 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -654,11 +654,13 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) inf = esr_to_fault_info(esr); - /* - * Return value ignored as we rely on signal merging. - * Future patches will make this more robust. - */ - apei_claim_sea(regs); + if (user_mode(regs) && apei_claim_sea(regs) == 0) { + /* + * APEI claimed this as a firmware-first notification. + * Some processing deferred to task_work before ret_to_user(). + */ + return 0; + } if (esr & ESR_ELx_FnV) siaddr = NULL; |