[PATCH V8 05/10] acpi: apei: handle SEA notification type for ARMv8

[Tyler Baicar <tbaicar@codeaurora.org>]

ARM APEI extension proposal added SEA (Synchronous External Abort)
notification type for ARMv8.
Add a new GHES error source handling function for SEA. If an error
source's notification type is SEA, then this function can be registered
into the SEA exception handler. That way GHES will parse and report
SEA exceptions when they occur.

Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org>
Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Signed-off-by: Naveen Kaje <nkaje@codeaurora.org>
---
 arch/arm64/Kconfig        |  2 ++
 arch/arm64/mm/fault.c     | 11 +++++++
 drivers/acpi/apei/Kconfig | 14 +++++++++
 drivers/acpi/apei/ghes.c  | 78 ++++++++++++++++++++++++++++++++++++++++++-----
 include/acpi/ghes.h       |  2 ++
 5 files changed, 100 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1117421..f92778d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -53,6 +53,8 @@ config ARM64
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_ACPI_APEI if (ACPI && EFI)
+	select HAVE_ACPI_APEI_SEA if (ACPI && EFI)
+	select HAVE_NMI if HAVE_ACPI_APEI_SEA
 	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_BITREVERSE
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 9ae7e65..5a5a096 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -30,6 +30,7 @@
 #include <linux/highmem.h>
 #include <linux/perf_event.h>
 #include <linux/preempt.h>
+#include <linux/hardirq.h>
 
 #include <asm/bug.h>
 #include <asm/cpufeature.h>
@@ -41,6 +42,8 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 
+#include <acpi/ghes.h>
+
 static const char *fault_name(unsigned int esr);
 
 #ifdef CONFIG_KPROBES
@@ -500,6 +503,14 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
 	pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
 		 fault_name(esr), esr, addr);
 
+	/*
+	 * synchronize_rcu() will wait for nmi_exit(), so no need to
+	 * rcu_read_lock().
+	 */
+	nmi_enter();
+	ghes_notify_sea();
+	nmi_exit();
+
 	info.si_signo = SIGBUS;
 	info.si_errno = 0;
 	info.si_code  = 0;
diff --git a/drivers/acpi/apei/Kconfig b/drivers/acpi/apei/Kconfig
index b0140c8..3786ff1 100644
--- a/drivers/acpi/apei/Kconfig
+++ b/drivers/acpi/apei/Kconfig
@@ -4,6 +4,20 @@ config HAVE_ACPI_APEI
 config HAVE_ACPI_APEI_NMI
 	bool
 
+config HAVE_ACPI_APEI_SEA
+	bool "APEI Synchronous External Abort logging/recovering support"
+	depends on ARM64
+	help
+	  This option should be enabled if the system supports
+	  firmware first handling of SEA (Synchronous External Abort).
+	  SEA happens with certain faults of data abort or instruction
+	  abort synchronous exceptions on ARMv8 systems. If a system
+	  supports firmware first handling of SEA, the platform analyzes
+	  and handles hardware error notifications with SEA, and it may then
+	  form a HW error record for the OS to parse and handle. This
+	  option allows the OS to look for such HW error record, and
+	  take appropriate action.
+
 config ACPI_APEI
 	bool "ACPI Platform Error Interface (APEI)"
 	select MISC_FILESYSTEMS
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index b25e7cf..8756172 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -114,11 +114,7 @@
  * Two virtual pages are used, one for IRQ/PROCESS context, the other for
  * NMI context (optionally).
  */
-#ifdef CONFIG_HAVE_ACPI_APEI_NMI
 #define GHES_IOREMAP_PAGES           2
-#else
-#define GHES_IOREMAP_PAGES           1
-#endif
 #define GHES_IOREMAP_IRQ_PAGE(base)	(base)
 #define GHES_IOREMAP_NMI_PAGE(base)	((base) + PAGE_SIZE)
 
@@ -156,11 +152,14 @@ static void ghes_ioremap_exit(void)
 
 static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn)
 {
-	unsigned long vaddr;
+	unsigned long vaddr, paddr;
+	pgprot_t prot;
 
 	vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr);
-	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
-			   pfn << PAGE_SHIFT, PAGE_KERNEL);
+
+	paddr = pfn << PAGE_SHIFT;
+	prot = arch_apei_get_mem_attribute(paddr);
+	ioremap_page_range(vaddr, vaddr + PAGE_SIZE, paddr, prot);
 
 	return (void __iomem *)vaddr;
 }
@@ -767,6 +766,48 @@ static int ghes_notify_sci(struct notifier_block *this,
 	.notifier_call = ghes_notify_sci,
 };
 
+#ifdef CONFIG_HAVE_ACPI_APEI_SEA
+static LIST_HEAD(ghes_sea);
+
+void ghes_notify_sea(void)
+{
+	struct ghes *ghes;
+
+	list_for_each_entry_rcu(ghes, &ghes_sea, list) {
+		ghes_proc(ghes);
+	}
+}
+
+static int ghes_sea_add(struct ghes *ghes)
+{
+	mutex_lock(&ghes_list_mutex);
+	list_add_rcu(&ghes->list, &ghes_sea);
+	mutex_unlock(&ghes_list_mutex);
+	return 0;
+}
+
+static void ghes_sea_remove(struct ghes *ghes)
+{
+	mutex_lock(&ghes_list_mutex);
+	list_del_rcu(&ghes->list);
+	mutex_unlock(&ghes_list_mutex);
+	synchronize_rcu();
+}
+#else /* CONFIG_HAVE_ACPI_APEI_SEA */
+static inline int ghes_sea_add(struct ghes *ghes)
+{
+	pr_err(GHES_PFX "ID: %d, trying to add SEA notification which is not supported\n",
+	       ghes->generic->header.source_id);
+	return -ENOTSUPP;
+}
+
+static inline void ghes_sea_remove(struct ghes *ghes)
+{
+	pr_err(GHES_PFX "ID: %d, trying to remove SEA notification which is not supported\n",
+	       ghes->generic->header.source_id);
+}
+#endif /* CONFIG_HAVE_ACPI_APEI_SEA */
+
 #ifdef CONFIG_HAVE_ACPI_APEI_NMI
 /*
  * printk is not safe in NMI context.  So in NMI handler, we allocate
@@ -1012,6 +1053,14 @@ static int ghes_probe(struct platform_device *ghes_dev)
 	case ACPI_HEST_NOTIFY_EXTERNAL:
 	case ACPI_HEST_NOTIFY_SCI:
 		break;
+	case ACPI_HEST_NOTIFY_SEA:
+		if (!IS_ENABLED(CONFIG_HAVE_ACPI_APEI_SEA)) {
+			pr_warn(GHES_PFX "Generic hardware error source: %d notified via SEA is not supported\n",
+				generic->header.source_id);
+			rc = -ENOTSUPP;
+			goto err;
+		}
+		break;
 	case ACPI_HEST_NOTIFY_NMI:
 		if (!IS_ENABLED(CONFIG_HAVE_ACPI_APEI_NMI)) {
 			pr_warn(GHES_PFX "Generic hardware error source: %d notified via NMI interrupt is not supported!\n",
@@ -1023,6 +1072,13 @@ static int ghes_probe(struct platform_device *ghes_dev)
 		pr_warning(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_GPIO:
+	case ACPI_HEST_NOTIFY_SEI:
+	case ACPI_HEST_NOTIFY_GSIV:
+		pr_warn(GHES_PFX "Generic hardware error source: %d notified via notification type %u is not supported\n",
+			generic->header.source_id, generic->header.source_id);
+		rc = -ENOTSUPP;
+		goto err;
 	default:
 		pr_warning(FW_WARN GHES_PFX "Unknown notification type: %u for generic hardware error source: %d\n",
 			   generic->notify.type, generic->header.source_id);
@@ -1077,6 +1133,11 @@ static int ghes_probe(struct platform_device *ghes_dev)
 		list_add_rcu(&ghes->list, &ghes_sci);
 		mutex_unlock(&ghes_list_mutex);
 		break;
+	case ACPI_HEST_NOTIFY_SEA:
+		rc = ghes_sea_add(ghes);
+		if (rc)
+			goto err_edac_unreg;
+		break;
 	case ACPI_HEST_NOTIFY_NMI:
 		ghes_nmi_add(ghes);
 		break;
@@ -1119,6 +1180,9 @@ static int ghes_remove(struct platform_device *ghes_dev)
 			unregister_acpi_hed_notifier(&ghes_notifier_sci);
 		mutex_unlock(&ghes_list_mutex);
 		break;
+	case ACPI_HEST_NOTIFY_SEA:
+		ghes_sea_remove(ghes);
+		break;
 	case ACPI_HEST_NOTIFY_NMI:
 		ghes_nmi_remove(ghes);
 		break;
diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h
index 6ae318b..adf5455 100644
--- a/include/acpi/ghes.h
+++ b/include/acpi/ghes.h
@@ -95,3 +95,5 @@ static inline void *acpi_hest_generic_data_payload(struct acpi_hest_generic_data
 		(void *)(((struct acpi_hest_generic_data_v300 *)(gdata)) + 1) :
 		gdata + 1;
 }
+
+void ghes_notify_sea(void);
-- 
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