[RFC PATCH v1 08/10] riscv: Introduce HEST SSE notification handlers

Himanshu Chauhan
2025-02-27T12:37:20Z

- Functions to register a ghes entry with SSE
- Add Handlers for low/high priority events
- Call ghes common handler to handle an error event

Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
---
drivers/acpi/apei/ghes.c | 100 ++++++++++++++++++++++++++++++++++-----
1 file changed, 89 insertions(+), 11 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 8a1029163799..59abb89d3547 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -17,6 +17,7 @@
* Author: Huang Ying <ying.huang@intel.com>
*/

+#include <linux/riscv_sse.h>
#include <linux/arm_sdei.h>
#include <linux/kernel.h>
#include <linux/moduleparam.h>
@@ -97,6 +98,11 @@
#define FIX_APEI_GHES_SDEI_CRITICAL __end_of_fixed_addresses
#endif

+#ifndef CONFIG_RISCV_SSE
+#define FIX_APEI_GHES_SSE_LOW_PRIORITY __end_of_fixed_addresses
+#define FIX_APEI_GHES_SSE_HIGH_PRIORITY __end_of_fixed_addresses
+#endif
+
static ATOMIC_NOTIFIER_HEAD(ghes_report_chain);

static inline bool is_hest_type_generic_v2(struct ghes *ghes)
@@ -1405,6 +1411,63 @@ static int apei_sdei_unregister_ghes(struct ghes *ghes)
return sdei_unregister_ghes(ghes);
}

+#if defined(CONFIG_ACPI_APEI_SSE)
+/* SSE Handlers */
+static int __ghes_sse_callback(struct ghes *ghes,
+ enum fixed_addresses fixmap_idx)
+{
+ if (!ghes_in_nmi_queue_one_entry(ghes, fixmap_idx)) {
+ irq_work_queue(&ghes_proc_irq_work);
+
+ return 0;
+ }
+
+ return -ENOENT;
+}
+
+/* Low priority */
+static int ghes_sse_lo_callback(u32 event_num, void *arg, struct pt_regs *regs)
+{
+ static DEFINE_RAW_SPINLOCK(ghes_notify_lock_sse_lo);
+ struct ghes *ghes = arg;
+ int err;
+
+ raw_spin_lock(&ghes_notify_lock_sse_lo);
+ err = __ghes_sse_callback(ghes, FIX_APEI_GHES_SSE_LOW_PRIORITY);
+ raw_spin_unlock(&ghes_notify_lock_sse_lo);
+
+ return err;
+}
+
+/* High priority */
+static int ghes_sse_hi_callback(u32 event_num, void *arg, struct pt_regs *regs)
+{
+ static DEFINE_RAW_SPINLOCK(ghes_notify_lock_sse_hi);
+ struct ghes *ghes = arg;
+ int err;
+
+ raw_spin_lock(&ghes_notify_lock_sse_hi);
+ err = __ghes_sse_callback(ghes, FIX_APEI_GHES_SSE_HIGH_PRIORITY);
+ raw_spin_unlock(&ghes_notify_lock_sse_hi);
+
+ return err;
+}
+
+static int apei_sse_register_ghes(struct ghes *ghes)
+{
+ return sse_register_ghes(ghes, ghes_sse_lo_callback,
+ ghes_sse_hi_callback);
+}
+
+static int apei_sse_unregister_ghes(struct ghes *ghes)
+{
+ return sse_unregister_ghes(ghes);
+}
+#else /* CONFIG_ACPI_APEI_SSE */
+static int apei_sse_register_ghes(struct ghes *ghes) { return -ENOTSUPP; }
+static int apei_sse_unregister_ghes(struct ghes *ghes) { return -ENOTSUPP; }
+#endif
+
static int ghes_probe(struct platform_device *ghes_dev)
{
struct acpi_hest_generic *generic;
@@ -1451,6 +1514,15 @@ static int ghes_probe(struct platform_device *ghes_dev)
pr_warn(GHES_PFX "Generic hardware error source: %d notified via local interrupt is not supported!\n",
generic->header.source_id);
goto err;
+ case ACPI_HEST_NOTIFY_SSE:
+ if (!IS_ENABLED(CONFIG_ACPI_APEI_SSE)) {
+ pr_warn(GHES_PFX "Generic hardware error source: %d "
+ "notified via SSE is not supported\n",
+ generic->header.source_id);
+ rc = -ENOTSUPP;
+ goto err;
+ }
+ break;
default:
pr_warn(FW_WARN GHES_PFX "Unknown notification type: %u for generic hardware error source: %d\n",
generic->notify.type, generic->header.source_id);
@@ -1514,6 +1586,18 @@ static int ghes_probe(struct platform_device *ghes_dev)
if (rc)
goto err;
break;
+
+ case ACPI_HEST_NOTIFY_SSE:
+ rc = apei_sse_register_ghes(ghes);
+ if (rc) {
+ pr_err(GHES_PFX "Failed to register for SSE notification"
+ " on vector %d\n",
+ generic->notify.vector);
+ goto err;
+ }
+ pr_err(GHES_PFX "Registered SSE notification on vector %d\n",
+ generic->notify.vector);
+ break;
default:
BUG();
}
@@ -1543,7 +1627,6 @@ static int ghes_probe(struct platform_device *ghes_dev)

static void ghes_remove(struct platform_device *ghes_dev)
{
- int rc;
struct ghes *ghes;
struct acpi_hest_generic *generic;

@@ -1577,16 +1660,11 @@ static void ghes_remove(struct platform_device *ghes_dev)
ghes_nmi_remove(ghes);
break;
case ACPI_HEST_NOTIFY_SOFTWARE_DELEGATED:
- rc = apei_sdei_unregister_ghes(ghes);
- if (rc) {
- /*
- * Returning early results in a resource leak, but we're
- * only here if stopping the hardware failed.
- */
- dev_err(&ghes_dev->dev, "Failed to unregister ghes (%pe)\n",
- ERR_PTR(rc));
- return;
- }
+ apei_sdei_unregister_ghes(ghes);
+ break;
+
+ case ACPI_HEST_NOTIFY_SSE:
+ apei_sse_unregister_ghes(ghes);
break;
default:
BUG();
--
2.43.0