ACPI: AGDI: Add driver for Arm Generic Diagnostic Dump and Reset device

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>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
index 6dba187..d4a7283 100644 (file)
--- 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 66acbe7..7b9e404 100644 (file)
--- 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 (file)
index 0000000..4df337d
--- /dev/null
+++ b/drivers/acpi/arm64/agdi.c
@@ -0,0 +1,116 @@
+// 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>
+#include <linux/platform_device.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 = 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 = dev_get_platdata(&pdev->dev);
+       int err, i;
+
+       err = sdei_event_disable(adata->sdei_event);
+       if (err)
+               return err;
+
+       for (i = 0; i < 3; i++) {
+               err = sdei_event_unregister(adata->sdei_event);
+               if (err != -EINPROGRESS)
+                       break;
+
+               schedule();
+       }
+
+       return err;
+}
+
+static struct platform_driver agdi_driver = {
+       .driver = {
+               .name = "agdi",
+       },
+       .probe = agdi_probe,
+       .remove = agdi_remove,
+};
+
+void __init acpi_agdi_init(void)
+{
+       struct acpi_table_agdi *agdi_table;
+       struct agdi_data pdata;
+       struct platform_device *pdev;
+       acpi_status status;
+
+       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");
+               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))
+               goto err_put_table;
+
+       if (platform_driver_register(&agdi_driver))
+               platform_device_unregister(pdev);
+
+err_put_table:
+       acpi_put_table((struct acpi_table_header *)agdi_table);
+}

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index cd37421..747a7f9 100644 (file)
--- 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>
@@ -1341,6 +1342,7 @@ 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 (file)
index 0000000..f477f0b
--- /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__ */