diff options
| author | James Morse <james.morse@arm.com> | 2018-11-13 11:03:42 +0000 |
|---|---|---|
| committer | Thomas Abraham <thomas.abraham@arm.com> | 2019-09-24 10:26:23 +0530 |
| commit | f64de87ffd3f1d8398732e75ca50408ecfd948e3 (patch) | |
| tree | 5f3a1afcf765361889380a065599e9f1bd22bddd | |
| parent | a4e32edf2a50ba399c213909e1362161a8d6373b (diff) | |
arm64: acpi: Make apei_claim_sea() synchronise with APEI's irq work
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>
Reviewed-by: Punit Agrawal <punit.agrawal@arm.com>
Tested-by: Tyler Baicar <tbaicar@codeaurora.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
CC: Xie XiuQi <xiexiuqi@huawei.com>
CC: gengdongjiu <gengdongjiu@huawei.com>
| -rw-r--r-- | arch/arm64/kernel/acpi.c | 23 | ||||
| -rw-r--r-- | arch/arm64/mm/fault.c | 9 |
2 files changed, 27 insertions, 5 deletions
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 3a58e9db5cfe..c29d9c2c5f3f 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -19,6 +19,7 @@ #include <linux/init.h> #include <linux/irq.h> #include <linux/irqdomain.h> +#include <linux/irq_work.h> #include <linux/memblock.h> #include <linux/of_fdt.h> #include <linux/smp.h> @@ -269,12 +270,17 @@ pgprot_t __acpi_get_mem_attribute(phys_addr_t addr) int apei_claim_sea(struct pt_regs *regs) { int err = -ENOENT; + bool return_to_irqs_enabled; unsigned long current_flags; if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES)) return err; current_flags = arch_local_save_flags(); + return_to_irqs_enabled = !irqs_disabled_flags(current_flags); + + if (regs) + return_to_irqs_enabled = interrupts_enabled(regs); /* * SEA can interrupt SError, mask it and describe this as an NMI so @@ -284,6 +290,23 @@ int apei_claim_sea(struct pt_regs *regs) nmi_enter(); err = ghes_notify_sea(); nmi_exit(); + + /* + * APEI NMI-like notifications are deferred to irq_work. Unless + * we interrupted irqs-masked code, we can do that now. + */ + if (!err) { + if (return_to_irqs_enabled) { + local_daif_restore(DAIF_PROCCTX_NOIRQ); + __irq_enter(); + irq_work_run(); + __irq_exit(); + } else { + pr_warn("APEI work queued but not completed"); + err = -EINPROGRESS; + } + } + local_daif_restore(current_flags); return err; diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 115d7a0e4b08..96111e55f93a 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -641,11 +641,10 @@ 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 (apei_claim_sea(regs) == 0) { + /* APEI claimed this as a firmware-first notification */ + return 0; + } if (esr & ESR_ELx_FnV) siaddr = NULL; |