[PATCH v2 2/2] soc: fujitsu: Add A64FX diagnostic interrupt driver
From: Hitomi Hasegawa
Date: Fri Mar 04 2022 - 01:47:13 EST
Enable diagnostic interrupts for the A64FX.
This is done using a pseudo-NMI.
Signed-off-by: Hitomi Hasegawa <hasegawa-hitomi@xxxxxxxxxxx>
---
MAINTAINERS | 5 +
drivers/soc/Kconfig | 1 +
drivers/soc/Makefile | 1 +
drivers/soc/fujitsu/Kconfig | 13 +++
drivers/soc/fujitsu/Makefile | 3 +
drivers/soc/fujitsu/a64fx-diag.c | 151 +++++++++++++++++++++++++++++++
6 files changed, 174 insertions(+)
create mode 100644 drivers/soc/fujitsu/Kconfig
create mode 100644 drivers/soc/fujitsu/Makefile
create mode 100644 drivers/soc/fujitsu/a64fx-diag.c
diff --git a/MAINTAINERS b/MAINTAINERS
index dd36acc87ce6..e9663fa92a52 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -239,6 +239,11 @@ F: include/trace/events/9p.h
F: include/uapi/linux/virtio_9p.h
F: net/9p/
+A64FX DIAG DRIVER
+M: Hitomi Hasegawa <hasegawa-hitomi@xxxxxxxxxxx>
+S: Supported
+F: drivers/soc/fujitsu/a64fx-diag.c
+
A8293 MEDIA DRIVER
M: Antti Palosaari <crope@xxxxxx>
L: linux-media@xxxxxxxxxxxxxxx
diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index e8a30c4c5aec..0405ff0b3be6 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -8,6 +8,7 @@ source "drivers/soc/atmel/Kconfig"
source "drivers/soc/bcm/Kconfig"
source "drivers/soc/canaan/Kconfig"
source "drivers/soc/fsl/Kconfig"
+source "drivers/soc/fujitsu/Kconfig"
source "drivers/soc/imx/Kconfig"
source "drivers/soc/ixp4xx/Kconfig"
source "drivers/soc/litex/Kconfig"
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index a05e9fbcd3e0..86596405a39c 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_SOC_CANAAN) += canaan/
obj-$(CONFIG_ARCH_DOVE) += dove/
obj-$(CONFIG_MACH_DOVE) += dove/
obj-y += fsl/
+obj-y += fujitsu/
obj-$(CONFIG_ARCH_GEMINI) += gemini/
obj-y += imx/
obj-y += ixp4xx/
diff --git a/drivers/soc/fujitsu/Kconfig b/drivers/soc/fujitsu/Kconfig
new file mode 100644
index 000000000000..b41cdac67637
--- /dev/null
+++ b/drivers/soc/fujitsu/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "fujitsu SoC drivers"
+
+config A64FX_DIAG
+ bool "A64FX diag driver"
+ depends on ARM64
+ help
+ Say Y here if you want to enable diag interrupt on A64FX.
+ This driver uses pseudo-NMI if available.
+
+ If unsure, say N.
+
+endmenu
diff --git a/drivers/soc/fujitsu/Makefile b/drivers/soc/fujitsu/Makefile
new file mode 100644
index 000000000000..945bc1c14ad0
--- /dev/null
+++ b/drivers/soc/fujitsu/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_A64FX_DIAG) += a64fx-diag.o
diff --git a/drivers/soc/fujitsu/a64fx-diag.c b/drivers/soc/fujitsu/a64fx-diag.c
new file mode 100644
index 000000000000..c6f895cf8912
--- /dev/null
+++ b/drivers/soc/fujitsu/a64fx-diag.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * A64FX diag driver.
+ */
+
+#include <linux/acpi.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sysrq.h>
+
+#define A64FX_DIAG_IRQ 1
+#define BMC_DIAG_INTERRUPT_STATUS_OFFSET (0x0044)
+#define BMC_INTERRUPT_STATUS_MASK ((1U) << 31)
+#define BMC_DIAG_INTERRUPT_ENABLE_OFFSET (0x0040)
+#define BMC_INTERRUPT_ENABLE_MASK ((1U) << 31)
+
+struct a64fx_diag_priv {
+ int irq;
+ void __iomem *mmsc_reg_base;
+ bool has_nmi;
+};
+
+static irqreturn_t a64fx_diag_handler(int irq, void *dev_id)
+{
+ handle_sysrq('c');
+
+ return IRQ_HANDLED;
+}
+
+static void a64fx_diag_interrupt_clear(struct a64fx_diag_priv *priv)
+{
+ u32 mmsc;
+ const void __iomem *diag_status_reg_addr;
+
+ diag_status_reg_addr = priv->mmsc_reg_base + BMC_DIAG_INTERRUPT_STATUS_OFFSET;
+ mmsc = readl(diag_status_reg_addr);
+ if (mmsc & BMC_INTERRUPT_STATUS_MASK)
+ writel(BMC_INTERRUPT_STATUS_MASK, (void *)diag_status_reg_addr);
+}
+
+static void a64fx_diag_interrupt_enable(struct a64fx_diag_priv *priv)
+{
+ u32 mmsc;
+ const void __iomem *diag_enable_reg_addr;
+
+ diag_enable_reg_addr = priv->mmsc_reg_base + BMC_DIAG_INTERRUPT_ENABLE_OFFSET;
+ mmsc = readl(diag_enable_reg_addr);
+ if (!(mmsc & BMC_INTERRUPT_ENABLE_MASK)) {
+ mmsc |= BMC_INTERRUPT_STATUS_MASK;
+ writel(mmsc, (void *)diag_enable_reg_addr);
+ }
+}
+
+static void a64fx_diag_interrupt_disable(struct a64fx_diag_priv *priv)
+{
+ u32 mmsc;
+ const void __iomem *diag_enable_reg_addr;
+
+ diag_enable_reg_addr = priv->mmsc_reg_base + BMC_DIAG_INTERRUPT_ENABLE_OFFSET;
+ mmsc = readl(diag_enable_reg_addr);
+ if (mmsc & BMC_INTERRUPT_ENABLE_MASK) {
+ mmsc &= ~BMC_INTERRUPT_ENABLE_MASK;
+ writel(mmsc, (void *)diag_enable_reg_addr);
+ }
+}
+
+static int a64fx_diag_probe(struct platform_device *pdev)
+{
+ int ret;
+ unsigned long irq_flags;
+ struct device *dev = &pdev->dev;
+ struct a64fx_diag_priv *priv;
+
+ priv = devm_kzalloc(dev, sizeof(struct a64fx_diag_priv), GFP_KERNEL);
+ if (priv == NULL)
+ return -ENOMEM;
+
+ priv->mmsc_reg_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->mmsc_reg_base))
+ return PTR_ERR(priv->mmsc_reg_base);
+
+ priv->irq = platform_get_irq(pdev, A64FX_DIAG_IRQ);
+ if (priv->irq < 0)
+ return priv->irq;
+
+ platform_set_drvdata(pdev, priv);
+
+ a64fx_diag_interrupt_clear(priv);
+ a64fx_diag_interrupt_enable(priv);
+
+ irq_flags = IRQF_PERCPU | IRQF_NOBALANCING | IRQF_NO_AUTOEN |
+ IRQF_NO_THREAD;
+ ret = request_nmi(priv->irq, &a64fx_diag_handler, irq_flags,
+ "a64fx_diag_nmi", NULL);
+ if (ret) {
+ ret = request_irq(priv->irq, &a64fx_diag_handler,
+ irq_flags, "a64fx_diag_irq", NULL);
+ if (ret) {
+ dev_err(dev, "cannot register IRQ %d\n", ret);
+ return ret;
+ }
+ enable_irq(priv->irq);
+ priv->has_nmi = false;
+ dev_info(dev, "registered for IRQ %d\n", priv->irq);
+ } else {
+ enable_nmi(priv->irq);
+ priv->has_nmi = true;
+ dev_info(dev, "registered for NMI %d\n", priv->irq);
+ }
+
+ return 0;
+}
+
+static int __exit a64fx_diag_remove(struct platform_device *pdev)
+{
+ struct a64fx_diag_priv *priv = platform_get_drvdata(pdev);
+
+ a64fx_diag_interrupt_disable(priv);
+ a64fx_diag_interrupt_clear(priv);
+
+ if (priv->has_nmi)
+ free_nmi(priv->irq, NULL);
+ else
+ free_irq(priv->irq, NULL);
+
+ return 0;
+}
+
+static const struct acpi_device_id a64fx_diag_acpi_match[] = {
+ { "FUJI2007", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, a64fx_diag_acpi_match);
+
+
+static struct platform_driver a64fx_diag_driver = {
+ .driver = {
+ .name = "a64fx_diag_driver",
+ .acpi_match_table = ACPI_PTR(a64fx_diag_acpi_match),
+ },
+ .probe = a64fx_diag_probe,
+ .remove = a64fx_diag_remove,
+};
+
+module_platform_driver(a64fx_diag_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Hitomi Hasegawa <hasegawa-hitomi@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("A64FX diag driver");
--
2.27.0