[PATCH v3 2/2] ACPI: AGDI: Add driver for Arm Generic Diagnostic Dump and Reset device

Ilkka Koskinen
2021-12-31T03:39:45Z

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@os.amperecomputing.com>
---
drivers/acpi/arm64/Kconfig | 8 +++
drivers/acpi/arm64/Makefile | 1 +
drivers/acpi/arm64/agdi.c | 125 ++++++++++++++++++++++++++++++++++++
3 files changed, 134 insertions(+)
create mode 100644 drivers/acpi/arm64/agdi.c

diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
index 6dba187f4f2e..24869ba5b365 100644
--- a/drivers/acpi/arm64/Kconfig
+++ b/drivers/acpi/arm64/Kconfig
@@ -8,3 +8,11 @@ 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.
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..6525ccbae5c1
--- /dev/null
+++ b/drivers/acpi/arm64/agdi.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This file implements handling of
+ * Arm Generic Diagnostic Dump and Reset Interface table (AGDI)
+ *
+ * Copyright (c) 2021, Ampere Computing LLC
+ */
+
+#define pr_fmt(fmt) "ACPI: AGDI: " fmt
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/arm_sdei.h>
+#include <linux/io.h>
+
+struct agdi_data {
+ int sdei_event;
+};
+
+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;
+}
+
+static int agdi_sdei_probe(struct platform_device *pdev,
+ struct agdi_data *adata)
+{
+ int err;
+
+ err = sdei_event_register(adata->sdei_event, agdi_sdei_handler, pdev);
+ if (err) {
+ dev_err(&pdev->dev, "Failed to register for SDEI event %d",
+ adata->sdei_event);
+ return err;
+ }
+
+ err = sdei_event_enable(adata->sdei_event);
+ if (err) {
+ sdei_event_unregister(adata->sdei_event);
+ dev_err(&pdev->dev, "Failed to enable event %d\n",
+ adata->sdei_event);
+ return err;
+ }
+
+ return 0;
+}
+
+static int agdi_probe(struct platform_device *pdev)
+{
+ struct agdi_data *adata;
+
+ adata = dev_get_platdata(&pdev->dev);
+ if (!adata)
+ return -EINVAL;
+
+ return agdi_sdei_probe(pdev, adata);
+}
+
+static int agdi_remove(struct platform_device *pdev)
+{
+ struct agdi_data *adata = platform_get_drvdata(pdev);
+
+ sdei_event_disable(adata->sdei_event);
+ sdei_event_unregister(adata->sdei_event);
+
+ return 0;
+}
+
+static struct platform_driver agdi_driver = {
+ .driver = {
+ .name = "agdi",
+ },
+ .probe = agdi_probe,
+ .remove = agdi_remove,
+};
+
+static int __init agdi_init(void)
+{
+ int ret;
+ acpi_status status;
+ struct acpi_table_agdi *agdi_table;
+ struct agdi_data pdata;
+ struct platform_device *pdev;
+
+ if (acpi_disabled)
+ return 0;
+
+ status = acpi_get_table(ACPI_SIG_AGDI, 0,
+ (struct acpi_table_header **) &agdi_table);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ if (agdi_table->flags & ACPI_AGDI_SIGNALING_MODE) {
+ pr_warn("Interrupt signaling is not supported");
+ ret = -ENODEV;
+ goto err_put_table;
+ }
+
+ pdata.sdei_event = agdi_table->sdei_event;
+
+ pdev = platform_device_register_data(NULL, "agdi", 0, &pdata, sizeof(pdata));
+ if (IS_ERR(pdev)) {
+ ret = PTR_ERR(pdev);
+ goto err_put_table;
+ }
+
+ ret = platform_driver_register(&agdi_driver);
+ if (ret)
+ goto err_device_unregister;
+
+ acpi_put_table((struct acpi_table_header *)agdi_table);
+ return 0;
+
+err_device_unregister:
+ platform_device_unregister(pdev);
+err_put_table:
+ acpi_put_table((struct acpi_table_header *)agdi_table);
+ return ret;
+}
+device_initcall(agdi_init);
--
2.17.1