3 files changed, 78 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h
index 966dd4bb23f2..f987b8a8f325 100644
--- a/arch/arm64/include/asm/fixmap.h
+++ b/arch/arm64/include/asm/fixmap.h
@@ -56,6 +56,10 @@ enum fixed_addresses {
         /* Used for GHES mapping from assorted contexts */
         FIX_APEI_GHES_IRQ,
         FIX_APEI_GHES_SEA,
+#ifdef CONFIG_ARM_SDE_INTERFACE
+        FIX_APEI_GHES_SDEI_NORMAL,
+        FIX_APEI_GHES_SDEI_CRITICAL,
+#endif
 #endif /* CONFIG_ACPI_APEI_GHES */
 
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
index c64c7da73829..e6376f985ef7 100644
--- a/drivers/firmware/arm_sdei.c
+++ b/drivers/firmware/arm_sdei.c
@@ -2,6 +2,7 @@
 // Copyright (C) 2017 Arm Ltd.
 #define pr_fmt(fmt) "sdei: " fmt
 
+#include <acpi/ghes.h>
 #include <linux/acpi.h>
 #include <linux/arm_sdei.h>
 #include <linux/arm-smccc.h>
@@ -887,6 +888,73 @@ static void sdei_smccc_hvc(unsigned long function_id,
         arm_smccc_hvc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res);
 }
 
+int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb,
+                       sdei_event_callback *critical_cb)
+{
+        int err;
+        u64 result;
+        u32 event_num;
+        sdei_event_callback *cb;
+
+        if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
+                return -EOPNOTSUPP;
+
+        event_num = ghes->generic->notify.vector;
+        if (event_num == 0) {
+                /*
+                 * Event 0 is reserved by the specification for
+                 * SDEI_EVENT_SIGNAL.
+                 */
+                return -EINVAL;
+        }
+
+        err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY,
+                                      &result);
+        if (err)
+                return err;
+
+        if (result == SDEI_EVENT_PRIORITY_CRITICAL)
+                cb = critical_cb;
+        else
+                cb = normal_cb;
+
+        err = sdei_event_register(event_num, cb, ghes);
+        if (!err)
+                err = sdei_event_enable(event_num);
+
+        return err;
+}
+
+int sdei_unregister_ghes(struct ghes *ghes)
+{
+        int i;
+        int err;
+        u32 event_num = ghes->generic->notify.vector;
+
+        might_sleep();
+
+        if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
+                return -EOPNOTSUPP;
+
+        /*
+         * The event may be running on another CPU. Disable it
+         * to stop new events, then try to unregister a few times.
+         */
+        err = sdei_event_disable(event_num);
+        if (err)
+                return err;
+
+        for (i = 0; i < 3; i++) {
+                err = sdei_event_unregister(event_num);
+                if (err != -EINPROGRESS)
+                        break;
+
+                schedule();
+        }
+
+        return err;
+}
+
 static int sdei_get_conduit(struct platform_device *pdev)
 {
         const char *method;
diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h
index 942afbd544b7..393899192906 100644
--- a/include/linux/arm_sdei.h
+++ b/include/linux/arm_sdei.h
@@ -11,6 +11,7 @@ enum sdei_conduit_types {
         CONDUIT_HVC,
 };
 
+#include <acpi/ghes.h>
 #include <asm/sdei.h>
 
 /* Arch code should override this to set the entry point from firmware... */
@@ -39,6 +40,11 @@ int sdei_event_unregister(u32 event_num);
 int sdei_event_enable(u32 event_num);
 int sdei_event_disable(u32 event_num);
 
+/* GHES register/unregister helpers */
+int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb,
+                       sdei_event_callback *critical_cb);
+int sdei_unregister_ghes(struct ghes *ghes);
+
 #ifdef CONFIG_ARM_SDE_INTERFACE
 /* For use by arch code when CPU hotplug notifiers are not appropriate. */
 int sdei_mask_local_cpu(void);