[PATCH v5 RESEND 2/2] ACPI: AGDI: Add support for Arm Generic Diagnostic Dump and Reset device

From: Ilkka Koskinen
Date: Fri Mar 04 2022 - 00:23:30 EST


ACPI for Arm Components 1.1 Platform Design Document v1.1 [0] specifices
Arm Generic Diagnostic Device Interface (AGDI). It allows an admin to
issue diagnostic dump and reset via an SDEI event or an interrupt.
This patch implements SDEI path.

[0] https://developer.arm.com/documentation/den0093/latest/

Signed-off-by: Ilkka Koskinen <ilkka@xxxxxxxxxxxxxxxxxxxxxx>
---
drivers/acpi/arm64/Kconfig | 10 +++++++
drivers/acpi/arm64/Makefile | 1 +
drivers/acpi/arm64/agdi.c | 52 +++++++++++++++++++++++++++++++++++++
drivers/acpi/bus.c | 2 ++
include/linux/acpi_agdi.h | 13 ++++++++++
5 files changed, 78 insertions(+)
create mode 100644 drivers/acpi/arm64/agdi.c
create mode 100644 include/linux/acpi_agdi.h

diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
index 6dba187f4f2e..d4a72835f328 100644
--- a/drivers/acpi/arm64/Kconfig
+++ b/drivers/acpi/arm64/Kconfig
@@ -8,3 +8,13 @@ config ACPI_IORT

config ACPI_GTDT
bool
+
+config ACPI_AGDI
+ bool "Arm Generic Diagnostic Dump and Reset Device Interface"
+ depends on ARM_SDE_INTERFACE
+ help
+ Arm Generic Diagnostic Dump and Reset Device Interface (AGDI) is
+ a standard that enables issuing a non-maskable diagnostic dump and
+ reset command.
+
+ If set, the kernel parses AGDI table and listens for the command.
diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
index 66acbe77f46e..7b9e4045659d 100644
--- a/drivers/acpi/arm64/Makefile
+++ b/drivers/acpi/arm64/Makefile
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_ACPI_AGDI) += agdi.o
obj-$(CONFIG_ACPI_IORT) += iort.o
obj-$(CONFIG_ACPI_GTDT) += gtdt.o
obj-y += dma.o
diff --git a/drivers/acpi/arm64/agdi.c b/drivers/acpi/arm64/agdi.c
new file mode 100644
index 000000000000..28916650d834
--- /dev/null
+++ b/drivers/acpi/arm64/agdi.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This file implements handling of
+ * Arm Generic Diagnostic Dump and Reset Interface table (AGDI)
+ *
+ * Copyright (c) 2022, Ampere Computing LLC
+ */
+
+#define pr_fmt(fmt) "ACPI: AGDI: " fmt
+
+#include <linux/acpi.h>
+#include <linux/arm_sdei.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+
+static int agdi_sdei_handler(u32 sdei_event, struct pt_regs *regs, void *arg)
+{
+ nmi_panic(regs, "Arm Generic Diagnostic Dump and Reset SDEI event issued");
+ return 0;
+}
+
+void __init acpi_agdi_init(void)
+{
+ struct acpi_table_agdi *agdi_table;
+ acpi_status status;
+ int sdei_event;
+
+ status = acpi_get_table(ACPI_SIG_AGDI, 0,
+ (struct acpi_table_header **) &agdi_table);
+ if (ACPI_FAILURE(status))
+ return;
+
+ if (agdi_table->flags & ACPI_AGDI_SIGNALING_MODE) {
+ pr_warn("Interrupt signaling is not supported");
+ acpi_put_table((struct acpi_table_header *)agdi_table);
+ return;
+ }
+
+ sdei_event = agdi_table->sdei_event;
+ acpi_put_table((struct acpi_table_header *)agdi_table);
+
+ if (sdei_event_register(sdei_event, agdi_sdei_handler, NULL)) {
+ pr_err("Failed to register for SDEI event %d", sdei_event);
+ return;
+ }
+
+ if (sdei_event_enable(sdei_event)) {
+ pr_err("Failed to enable SDEI event %d\n", sdei_event);
+ sdei_event_unregister(sdei_event);
+ return;
+ }
+}
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index eaa511fc9c66..87b93f4df0cf 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -26,6 +26,7 @@
#include <asm/mpspec.h>
#include <linux/dmi.h>
#endif
+#include <linux/acpi_agdi.h>
#include <linux/acpi_iort.h>
#include <linux/acpi_viot.h>
#include <linux/pci.h>
@@ -1386,6 +1387,7 @@ static int __init acpi_init(void)
acpi_debugger_init();
acpi_setup_sb_notify_handler();
acpi_viot_init();
+ acpi_agdi_init();
return 0;
}

diff --git a/include/linux/acpi_agdi.h b/include/linux/acpi_agdi.h
new file mode 100644
index 000000000000..f477f0b452fa
--- /dev/null
+++ b/include/linux/acpi_agdi.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ACPI_AGDI_H__
+#define __ACPI_AGDI_H__
+
+#include <linux/acpi.h>
+
+#ifdef CONFIG_ACPI_AGDI
+void __init acpi_agdi_init(void);
+#else
+static inline void acpi_agdi_init(void) {}
+#endif
+#endif /* __ACPI_AGDI_H__ */
--
2.17.1