[PATCH] ACPI / APEI: restore interrupt before panic in sdei flow

Liguang Zhang
2021-10-11T15:12:59Z

We use ACPI_HEST_NOTIFY_SOFTWARE_DELEGATED Notify type for ras event.

In ATF:
ehf_activate_priority()
dispatch sdei()
ehf_deactivate_priority()

If ras error severity is fatal, panic was called in sdei(),
ehf_deactivate_priority was not called. we should restore interrupt before panic
otherwise kdump will trigger error.

Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
---
drivers/acpi/apei/ghes.c | 25 +++++++++++++++++++++----
drivers/firmware/arm_sdei.c | 14 ++++++++++++++
include/linux/arm_sdei.h | 2 ++
3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 0c8330ed1ffd..4f734c60987c 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -141,6 +141,7 @@ static unsigned long ghes_estatus_pool_size_request;
static struct ghes_estatus_cache *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
static atomic_t ghes_estatus_cache_alloced;

+static bool ghes_sdei_callback;
static int ghes_panic_timeout __read_mostly = 30;

static void __iomem *ghes_map(u64 pfn, enum fixed_addresses fixmap_idx)
@@ -837,18 +838,30 @@ static void ghes_estatus_cache_add(
rcu_read_unlock();
}

+static void sdei_api_restore_ras(void)
+{
+ /* reboot to log the error! */
+ if (!panic_timeout)
+ panic_timeout = ghes_panic_timeout;
+ panic("Fatal hardware error!");
+}
+
static void __ghes_panic(struct ghes *ghes,
struct acpi_hest_generic_status *estatus,
u64 buf_paddr, enum fixed_addresses fixmap_idx)
{
+ int err;
+
__ghes_print_estatus(KERN_EMERG, ghes->generic, estatus);

ghes_clear_estatus(ghes, estatus, buf_paddr, fixmap_idx);

- /* reboot to log the error! */
- if (!panic_timeout)
- panic_timeout = ghes_panic_timeout;
- panic("Fatal hardware error!");
+ if (ghes_sdei_callback) {
+ err = sdei_api_event_complete_and_resume((unsigned long)sdei_api_restore_ras);
+ if (err)
+ sdei_api_restore_ras();
+ } else
+ sdei_api_restore_ras();
}

static int ghes_proc(struct ghes *ghes)
@@ -1224,7 +1237,9 @@ static int ghes_sdei_normal_callback(u32 event_num, struct pt_regs *regs,
int err;

raw_spin_lock(&ghes_notify_lock_sdei_normal);
+ ghes_sdei_callback = true;
err = __ghes_sdei_callback(ghes, FIX_APEI_GHES_SDEI_NORMAL);
+ ghes_sdei_callback = false;
raw_spin_unlock(&ghes_notify_lock_sdei_normal);

return err;
@@ -1238,7 +1253,9 @@ static int ghes_sdei_critical_callback(u32 event_num, struct pt_regs *regs,
int err;

raw_spin_lock(&ghes_notify_lock_sdei_critical);
+ ghes_sdei_callback = true;
err = __ghes_sdei_callback(ghes, FIX_APEI_GHES_SDEI_CRITICAL);
+ ghes_sdei_callback = false;
raw_spin_unlock(&ghes_notify_lock_sdei_critical);

return err;
diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
index a7e762c352f9..1af6b6b55c57 100644
--- a/drivers/firmware/arm_sdei.c
+++ b/drivers/firmware/arm_sdei.c
@@ -473,6 +473,20 @@ static int sdei_api_event_unregister(u32 event_num)
0, 0, 0, NULL);
}

+int sdei_api_event_complete_and_resume(u64 addr)
+{
+ int err;
+
+ err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_COMPLETE_AND_RESUME, addr,
+ 0, 0, 0, 0, NULL);
+ if (err && err != -EIO) {
+ pr_warn_once("failed to restore CPU[%u]: %d\n", smp_processor_id(), err);
+ return err;
+ }
+
+ return 0;
+}
+
/* Called directly by the hotplug callbacks */
static void _local_event_unregister(void *data)
{
diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h
index 0a241c5c911d..b6d347085834 100644
--- a/include/linux/arm_sdei.h
+++ b/include/linux/arm_sdei.h
@@ -46,9 +46,11 @@ int sdei_unregister_ghes(struct ghes *ghes);
/* For use by arch code when CPU hotplug notifiers are not appropriate. */
int sdei_mask_local_cpu(void);
int sdei_unmask_local_cpu(void);
+int sdei_api_event_complete_and_resume(u64 addr);
#else
static inline int sdei_mask_local_cpu(void) { return 0; }
static inline int sdei_unmask_local_cpu(void) { return 0; }
+int sdei_api_event_complete_and_resume(u64 addr) { return 0; }
#endif /* CONFIG_ARM_SDE_INTERFACE */

--
2.19.1.6.gb485710b