[PATCH v4 0/4] drivers: misc: Add support for TMR Manager and Inject IPs

[PATCH v4 0/4] drivers: misc: Add support for TMR Manager and Inject IPs

[Appana Durga Kedareswara rao]

This patch series adds support for TMR Manager and TMR Inject IPs.
The TMR Manager is responsible for handling the TMR subsystem state,
including fault detection and error recovery. The core is triplicated
in each of the sub-blocks in the TMR subsystem, and provides majority
voting of its internal state.
The TMR Inject core provides functional fault injection by changing
selected MicroBlaze instructions, which provides the possibility to
verify that the TMR subsystem error detection and fault recovery logic
is working properly.

For more details about TMR Manager and Inject IPs please refer PG268[1].

[1]: https://docs.xilinx.com/r/en-US/pg268-tmr/Triple-Modular-Redundancy-TMR-v1.0-LogiCORE-IP-Product-Guide-PG268

Appana Durga Kedareswara rao (4):
  dt-bindings: misc: tmr-manager: Add device-tree binding for TMR
    Manager
  drivers: misc: Add Support for TMR Manager
  dt-bindings: misc: tmr-inject: Add device-tree binding for TMR Inject
  drivers: misc: Add Support for TMR Inject IP

 .../testing/sysfs-driver-xilinx-tmr-manager   |  16 ++
 .../bindings/misc/xlnx,tmr-inject.yaml        |  47 ++++
 .../bindings/misc/xlnx,tmr-manager.yaml       |  47 ++++
 MAINTAINERS                                   |  13 +
 drivers/misc/Kconfig                          |  20 ++
 drivers/misc/Makefile                         |   4 +-
 drivers/misc/xilinx_tmr_inject.c              | 173 ++++++++++++++
 drivers/misc/xilinx_tmr_manager.c             | 222 ++++++++++++++++++
 8 files changed, 541 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
 create mode 100644 Documentation/devicetree/bindings/misc/xlnx,tmr-inject.yaml
 create mode 100644 Documentation/devicetree/bindings/misc/xlnx,tmr-manager.yaml
 create mode 100644 drivers/misc/xilinx_tmr_inject.c
 create mode 100644 drivers/misc/xilinx_tmr_manager.c

-- 
2.25.1


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[PATCH v4 1/4] dt-bindings: misc: tmr-manager: Add device-tree binding for TMR Manager

[Appana Durga Kedareswara rao]

Triple Modular Redundancy(TMR) subsystem contains three microblaze cores,
subsystem is fault-tolerant and continues to operate nominally after
encountering an error. Together with the capability to detect and recover
from errors, the implementation ensures the reliability of the entire
subsystem.  TMR Manager is responsible for performing recovery of the
subsystem detects the fault via a break signal it invokes microblaze
software break handler which calls the tmr manager driver api to
update the error count and status.

Signed-off-by: Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
Changes for v4:
--> None.
Changes for v3:
--> Added Krzysztof Reviewed by.
Changes for v2:
--> Added minimum and maximum values for xlnx,magic1 property as suggested
by Michal.
--> Fixed 80 char limit in description as suggested by Michal.

 .../bindings/misc/xlnx,tmr-manager.yaml       | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/misc/xlnx,tmr-manager.yaml

diff --git a/Documentation/devicetree/bindings/misc/xlnx,tmr-manager.yaml b/Documentation/devicetree/bindings/misc/xlnx,tmr-manager.yaml
new file mode 100644
index 000000000000..27de12147a52
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/xlnx,tmr-manager.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/misc/xlnx,tmr-manager.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Xilinx Triple Modular Redundancy(TMR) Manager IP
+
+maintainers:
+  - Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
+
+description: |
+  The Triple Modular Redundancy(TMR) Manager is responsible for handling the
+  TMR subsystem state, including fault detection and error recovery. The core
+  is triplicated in each of the sub-blocks in the TMR subsystem, and provides
+  majority voting of its internal state.
+
+properties:
+  compatible:
+    enum:
+      - xlnx,tmr-manager-1.0
+
+  reg:
+    maxItems: 1
+
+  xlnx,magic1:
+    minimum: 0
+    maximum: 255
+    description:
+      Magic byte 1, When configured it allows the controller to perform
+      recovery.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+required:
+  - compatible
+  - reg
+  - xlnx,magic1
+
+additionalProperties: false
+
+examples:
+  - |
+    tmr-manager@44a10000 {
+        compatible = "xlnx,tmr-manager-1.0";
+        reg = <0x44a10000 0x10000>;
+        xlnx,magic1 = <0x46>;
+    };
-- 
2.25.1


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[PATCH v4 2/4] drivers: misc: Add Support for TMR Manager

[Appana Durga Kedareswara rao]

Triple Modular Redundancy(TMR) subsystem contains three microblaze cores,
subsystem is fault-tolerant and continues to operate nominally after
encountering an error. Together with the capability to detect and recover
from errors, the implementation ensures the reliability of the entire
subsystem.  TMR Manager is responsible for performing recovery of the
subsystem detects the fault via a break signal it invokes microblaze
software break handler which calls the tmr manager driver api to
update the error count and status, added support for fault detection
feature via sysfs interface.

Usage:
To know the break handler count(Error count):
cat /sys/devices/platform/amba_pl/44a10000.tmr_manager/errcnt

Signed-off-by: Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
---
Changes for v4:
--> None.
Changes for v3:
--> Corrected month in the sysfs-driver-xilinx-tmr-manager file
--> Updated the Kconfig to compile the driver as a module
--> Removed unneeded status sysfs attribute
Changes for v2:
--> Fixed Month in the sysfs description.
--> Fixed line over 80 char in driver.
--> Replaced kstrtol with kstrtoul as suggested by Michal.
--> Added error check for xlnx,magic1 value.

 .../testing/sysfs-driver-xilinx-tmr-manager   |  16 ++
 MAINTAINERS                                   |   7 +
 drivers/misc/Kconfig                          |  10 +
 drivers/misc/Makefile                         |   3 +-
 drivers/misc/xilinx_tmr_manager.c             | 222 ++++++++++++++++++
 5 files changed, 257 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
 create mode 100644 drivers/misc/xilinx_tmr_manager.c

diff --git a/Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager b/Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
new file mode 100644
index 000000000000..2a97be6ae849
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
@@ -0,0 +1,16 @@
+What:		/sys/devices/platform/amba_pl/<dev>/errcnt
+Date:		Sep 2022
+Contact:	appana.durga.kedareswara.rao@amd.com
+Description:	This control file provides the fault detection count.
+		This file cannot be written.
+		Example:
+		# cat /sys/devices/platform/amba_pl/44a10000.tmr_manager/errcnt
+		  1
+
+What:		/sys/devices/platform/amba_pl/<dev>/dis_block_break
+Date:		Sep 2022
+Contact:	appana.durga.kedareswara.rao@amd.com
+Description:	Write any value to it, This control file enables the break signal.
+		This file is write only.
+		Example:
+		# echo <any value> > /sys/devices/platform/amba_pl/44a10000.tmr_manager/dis_block_break
diff --git a/MAINTAINERS b/MAINTAINERS
index f1390b8270b2..5fc5ec13985e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13277,6 +13277,13 @@ W:	http://www.monstr.eu/fdt/
 T:	git git://git.monstr.eu/linux-2.6-microblaze.git
 F:	arch/microblaze/
 
+MICROBLAZE TMR MANAGER
+M:	Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
+S:	Supported
+F:	Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
+F:	Documentation/devicetree/bindings/misc/xlnx,tmr-manager.yaml
+F:	drivers/misc/xilinx_tmr_manager.c
+
 MICROCHIP AT91 DMA DRIVERS
 M:	Ludovic Desroches <ludovic.desroches@microchip.com>
 M:	Tudor Ambarus <tudor.ambarus@microchip.com>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 94e9fb4cdd76..1508cc29b05a 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -496,6 +496,16 @@ config VCPU_STALL_DETECTOR
 
 	  If you do not intend to run this kernel as a guest, say N.
 
+config TMR_MANAGER
+	tristate "Select TMR Manager"
+	depends on MICROBLAZE && MB_MANAGER
+	help
+	  This option enables the driver developed for TMR Manager. The Triple
+	  Modular Redundancy(TMR) manager provides support for fault detection
+	  via sysfs interface.
+
+	  Say N here unless you know what you are doing.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 2be8542616dd..4918f6632531 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -60,4 +60,5 @@ obj-$(CONFIG_XILINX_SDFEC)	+= xilinx_sdfec.o
 obj-$(CONFIG_HISI_HIKEY_USB)	+= hisi_hikey_usb.o
 obj-$(CONFIG_HI6421V600_IRQ)	+= hi6421v600-irq.o
 obj-$(CONFIG_OPEN_DICE)		+= open-dice.o
-obj-$(CONFIG_VCPU_STALL_DETECTOR)	+= vcpu_stall_detector.o
\ No newline at end of file
+obj-$(CONFIG_VCPU_STALL_DETECTOR)	+= vcpu_stall_detector.o
+obj-$(CONFIG_TMR_MANAGER)      += xilinx_tmr_manager.o
diff --git a/drivers/misc/xilinx_tmr_manager.c b/drivers/misc/xilinx_tmr_manager.c
new file mode 100644
index 000000000000..39365e0cb6e6
--- /dev/null
+++ b/drivers/misc/xilinx_tmr_manager.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx TMR Subsystem.
+ *
+ * Copyright (C) 2022 Xilinx, Inc.
+ *
+ * Description:
+ * This driver is developed for TMR Manager,The Triple Modular Redundancy(TMR)
+ * Manager is responsible for handling the TMR subsystem state, including
+ * fault detection and error recovery. The core is triplicated in each of
+ * the sub-blocks in the TMR subsystem, and provides majority voting of
+ * its internal state provides soft error detection, correction and
+ * recovery. Error detection feature is provided through sysfs
+ * entries which allow the user to observer the TMR microblaze
+ * status.
+ */
+
+#include <asm/xilinx_mb_manager.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+/* TMR Manager Register offsets */
+#define XTMR_MANAGER_CR_OFFSET		0x0
+#define XTMR_MANAGER_FFR_OFFSET		0x4
+#define XTMR_MANAGER_CMR0_OFFSET	0x8
+#define XTMR_MANAGER_CMR1_OFFSET	0xC
+#define XTMR_MANAGER_BDIR_OFFSET	0x10
+#define XTMR_MANAGER_SEMIMR_OFFSET	0x1C
+
+/* Register Bitmasks/shifts */
+#define XTMR_MANAGER_CR_MAGIC1_MASK	GENMASK(7, 0)
+#define XTMR_MANAGER_CR_MAGIC2_MASK	GENMASK(15, 8)
+#define XTMR_MANAGER_CR_RIR_MASK	BIT(16)
+#define XTMR_MANAGER_FFR_LM12_MASK	BIT(0)
+#define XTMR_MANAGER_FFR_LM13_MASK	BIT(1)
+#define XTMR_MANAGER_FFR_LM23_MASK	BIT(2)
+
+#define XTMR_MANAGER_CR_MAGIC2_SHIFT	4
+#define XTMR_MANAGER_CR_RIR_SHIFT	16
+#define XTMR_MANAGER_CR_BB_SHIFT	18
+
+#define XTMR_MANAGER_MAGIC1_MAX_VAL	255
+
+/**
+ * struct xtmr_manager_dev - Driver data for TMR Manager
+ * @regs: device physical base address
+ * @cr_val: control register value
+ * @magic1: Magic 1 hardware configuration value
+ * @err_cnt: error statistics count
+ * @phys_baseaddr: Physical base address
+ */
+struct xtmr_manager_dev {
+	void __iomem *regs;
+	u32 cr_val;
+	u32 magic1;
+	u32 err_cnt;
+	resource_size_t phys_baseaddr;
+};
+
+/* IO accessors */
+static inline void xtmr_manager_write(struct xtmr_manager_dev *xtmr_manager,
+				      u32 addr, u32 value)
+{
+	iowrite32(value, xtmr_manager->regs + addr);
+}
+
+static inline u32 xtmr_manager_read(struct xtmr_manager_dev *xtmr_manager,
+				    u32 addr)
+{
+	return ioread32(xtmr_manager->regs + addr);
+}
+
+static void xmb_manager_reset_handler(struct xtmr_manager_dev *xtmr_manager)
+{
+	/* Clear the FFR Register contents as a part of recovery process. */
+	xtmr_manager_write(xtmr_manager, XTMR_MANAGER_FFR_OFFSET, 0);
+}
+
+static void xmb_manager_update_errcnt(struct xtmr_manager_dev *xtmr_manager)
+{
+	xtmr_manager->err_cnt++;
+}
+
+static ssize_t errcnt_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct xtmr_manager_dev *xtmr_manager = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%x\n", xtmr_manager->err_cnt);
+}
+static DEVICE_ATTR_RO(errcnt);
+
+static ssize_t dis_block_break_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t size)
+{
+	struct xtmr_manager_dev *xtmr_manager = dev_get_drvdata(dev);
+	int ret;
+	long value;
+
+	ret = kstrtoul(buf, 16, &value);
+	if (ret)
+		return ret;
+
+	/* unblock the break signal*/
+	xtmr_manager->cr_val &= ~(1 << XTMR_MANAGER_CR_BB_SHIFT);
+	xtmr_manager_write(xtmr_manager, XTMR_MANAGER_CR_OFFSET,
+			   xtmr_manager->cr_val);
+	return size;
+}
+static DEVICE_ATTR_WO(dis_block_break);
+
+static struct attribute *xtmr_manager_dev_attrs[] = {
+	&dev_attr_dis_block_break.attr,
+	&dev_attr_errcnt.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(xtmr_manager_dev);
+
+static void xtmr_manager_init(struct xtmr_manager_dev *xtmr_manager)
+{
+	/* Clear the SEM interrupt mask register to disable the interrupt */
+	xtmr_manager_write(xtmr_manager, XTMR_MANAGER_SEMIMR_OFFSET, 0);
+
+	/* Allow recovery reset by default */
+	xtmr_manager->cr_val = (1 << XTMR_MANAGER_CR_RIR_SHIFT) |
+				xtmr_manager->magic1;
+	xtmr_manager_write(xtmr_manager, XTMR_MANAGER_CR_OFFSET,
+			   xtmr_manager->cr_val);
+	/*
+	 * Configure Break Delay Initialization Register to zero so that
+	 * break occurs immediately
+	 */
+	xtmr_manager_write(xtmr_manager, XTMR_MANAGER_BDIR_OFFSET, 0);
+
+	/*
+	 * To come out of break handler need to block the break signal
+	 * in the tmr manager, update the xtmr_manager cr_val for the same
+	 */
+	xtmr_manager->cr_val |= (1 << XTMR_MANAGER_CR_BB_SHIFT);
+
+	/*
+	 * When the break vector gets asserted because of error injection,
+	 * the break signal must be blocked before exiting from the
+	 * break handler, Below api updates the TMR manager address and
+	 * control register and error counter callback arguments,
+	 * which will be used by the break handler to block the
+	 * break and call the callback function.
+	 */
+	xmb_manager_register(xtmr_manager->phys_baseaddr, xtmr_manager->cr_val,
+			     (void *)xmb_manager_update_errcnt,
+			     xtmr_manager, (void *)xmb_manager_reset_handler);
+}
+
+/**
+ * xtmr_manager_probe - Driver probe function
+ * @pdev: Pointer to the platform_device structure
+ *
+ * This is the driver probe routine. It does all the memory
+ * allocation and creates sysfs entries for the device.
+ *
+ * Return: 0 on success and failure value on error
+ */
+static int xtmr_manager_probe(struct platform_device *pdev)
+{
+	struct xtmr_manager_dev *xtmr_manager;
+	struct resource *res;
+	int err;
+
+	xtmr_manager = devm_kzalloc(&pdev->dev, sizeof(*xtmr_manager),
+				    GFP_KERNEL);
+	if (!xtmr_manager)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	xtmr_manager->regs =  devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(xtmr_manager->regs))
+		return PTR_ERR(xtmr_manager->regs);
+
+	xtmr_manager->phys_baseaddr = res->start;
+
+	err = of_property_read_u32(pdev->dev.of_node, "xlnx,magic1",
+				   &xtmr_manager->magic1);
+	if (err < 0) {
+		dev_err(&pdev->dev, "unable to read xlnx,magic1 property");
+		return err;
+	}
+
+	if (xtmr_manager->magic1 > XTMR_MANAGER_MAGIC1_MAX_VAL) {
+		dev_err(&pdev->dev, "invalid xlnx,magic1 property value");
+		return -EINVAL;
+	}
+
+	/* Initialize TMR Manager */
+	xtmr_manager_init(xtmr_manager);
+
+	platform_set_drvdata(pdev, xtmr_manager);
+
+	return 0;
+}
+
+static const struct of_device_id xtmr_manager_of_match[] = {
+	{
+		.compatible = "xlnx,tmr-manager-1.0",
+	},
+	{ /* end of table */ }
+};
+MODULE_DEVICE_TABLE(of, xtmr_manager_of_match);
+
+static struct platform_driver xtmr_manager_driver = {
+	.driver = {
+		.name = "xilinx-tmr_manager",
+		.of_match_table = xtmr_manager_of_match,
+		.dev_groups = xtmr_manager_dev_groups,
+	},
+	.probe = xtmr_manager_probe,
+};
+module_platform_driver(xtmr_manager_driver);
+
+MODULE_AUTHOR("Xilinx, Inc");
+MODULE_DESCRIPTION("Xilinx TMR Manager Driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1


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[PATCH v4 3/4] dt-bindings: misc: tmr-inject: Add device-tree binding for TMR Inject

[Appana Durga Kedareswara rao]

The Triple Modular Redundancy(TMR) Inject core provides functional fault
injection by changing selected MicroBlaze instructions, which provides the
possibility to verify that the TMR subsystem error detection and fault
recovery logic is working properly.

Signed-off-by: Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
Changes for v4:
--> None.
Changes for v3:
--> Added Krzysztof Reviewed by.
Changes for v2:
--> Added minimum and maximum values for xlnx,magic1 property as suggested
by Michal.
--> Fixed 80 char limit in description as suggested by Michal.

 .../bindings/misc/xlnx,tmr-inject.yaml        | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/misc/xlnx,tmr-inject.yaml

diff --git a/Documentation/devicetree/bindings/misc/xlnx,tmr-inject.yaml b/Documentation/devicetree/bindings/misc/xlnx,tmr-inject.yaml
new file mode 100644
index 000000000000..1b6020e4ec27
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/xlnx,tmr-inject.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/misc/xlnx,tmr-inject.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Xilinx Triple Modular Redundancy(TMR) Inject IP
+
+maintainers:
+  - Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
+
+description: |
+  The Triple Modular Redundancy(TMR) Inject core provides functional fault
+  injection by changing selected MicroBlaze instructions, which provides the
+  possibility to verify that the TMR subsystem error detection and fault
+  recovery logic is working properly.
+
+properties:
+  compatible:
+    enum:
+      - xlnx,tmr-inject-1.0
+
+  reg:
+    maxItems: 1
+
+  xlnx,magic:
+    minimum: 0
+    maximum: 255
+    description: |
+      Magic number, When configured it allows the controller to perform
+      recovery.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+required:
+  - compatible
+  - reg
+  - xlnx,magic
+
+additionalProperties: false
+
+examples:
+  - |
+    fault-inject@44a30000 {
+        compatible = "xlnx,tmr-inject-1.0";
+        reg = <0x44a10000 0x10000>;
+        xlnx,magic = <0x46>;
+    };
-- 
2.25.1


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[PATCH v4 4/4] drivers: misc: Add Support for TMR Inject IP

[Appana Durga Kedareswara rao]

The Triple Modular Redundancy(TMR) provides functional fault injection by
changing selected MicroBlaze instructions, which provides the possibility
to verify that the TMR subsystem error detection and fault recovery logic
is working properly, provided sysfs entries which allow the user to inject
a fault.

Usage:
echo 1 > /sys/kernel/debug/xtmr_inject/inject_fault/inject_fault

Signed-off-by: Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
---
Changes for v4:
--> Update depends on with FAULT_INJECTION_DEBUG_FS instead of
FAULT_INJECTION.
Changes for v3:
--> Updated the driver to use fault-injection api as suggested by Greg.
--> Updated the Kconfig to compile the driver as a module.
Changes for v2:
--> Fixed Month in the sysfs description.
--> Fixed line over 80 char in driver.
--> Replaced kstrtol with kstrtoul as suggested by Michal.
--> Added error check for xlnx,magic value.

 MAINTAINERS                      |   6 ++
 drivers/misc/Kconfig             |  10 ++
 drivers/misc/Makefile            |   1 +
 drivers/misc/xilinx_tmr_inject.c | 173 +++++++++++++++++++++++++++++++
 4 files changed, 190 insertions(+)
 create mode 100644 drivers/misc/xilinx_tmr_inject.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 5fc5ec13985e..1207effa8e15 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13284,6 +13284,12 @@ F:	Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
 F:	Documentation/devicetree/bindings/misc/xlnx,tmr-manager.yaml
 F:	drivers/misc/xilinx_tmr_manager.c
 
+MICROBLAZE TMR INJECT
+M:	Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
+S:	Supported
+F:	Documentation/devicetree/bindings/misc/xlnx,tmr-inject.yaml
+F:	drivers/misc/xilinx_tmr_inject.c
+
 MICROCHIP AT91 DMA DRIVERS
 M:	Ludovic Desroches <ludovic.desroches@microchip.com>
 M:	Tudor Ambarus <tudor.ambarus@microchip.com>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 1508cc29b05a..9f8372497ad8 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -506,6 +506,16 @@ config TMR_MANAGER
 
 	  Say N here unless you know what you are doing.
 
+config TMR_INJECT
+	tristate "Select TMR Inject"
+	depends on TMR_MANAGER && FAULT_INJECTION_DEBUG_FS
+	help
+	  This option enables the driver developed for TMR Inject.
+	  The Triple Modular Redundancy(TMR) Inject provides
+	  fault injection.
+
+	  Say N here unless you know what you are doing.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 4918f6632531..fff8606d505c 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -62,3 +62,4 @@ obj-$(CONFIG_HI6421V600_IRQ)	+= hi6421v600-irq.o
 obj-$(CONFIG_OPEN_DICE)		+= open-dice.o
 obj-$(CONFIG_VCPU_STALL_DETECTOR)	+= vcpu_stall_detector.o
 obj-$(CONFIG_TMR_MANAGER)      += xilinx_tmr_manager.o
+obj-$(CONFIG_TMR_INJECT)	+= xilinx_tmr_inject.o
diff --git a/drivers/misc/xilinx_tmr_inject.c b/drivers/misc/xilinx_tmr_inject.c
new file mode 100644
index 000000000000..da42cb1a0ee0
--- /dev/null
+++ b/drivers/misc/xilinx_tmr_inject.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Xilinx TMR Inject IP.
+ *
+ * Copyright (C) 2022 Xilinx, Inc.
+ *
+ * Description:
+ * This driver is developed for TMR Inject IP,The Triple Modular Redundancy(TMR)
+ * Inject provides fault injection.
+ * Fault injection and detection features are provided through sysfs entries
+ * which allow the user to generate a fault.
+ */
+
+#include <asm/xilinx_mb_manager.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/fault-inject.h>
+
+/* TMR Inject Register offsets */
+#define XTMR_INJECT_CR_OFFSET		0x0
+#define XTMR_INJECT_AIR_OFFSET		0x4
+#define XTMR_INJECT_IIR_OFFSET		0xC
+#define XTMR_INJECT_EAIR_OFFSET		0x10
+#define XTMR_INJECT_ERR_OFFSET		0x204
+
+/* Register Bitmasks/shifts */
+#define XTMR_INJECT_CR_CPUID_SHIFT	8
+#define XTMR_INJECT_CR_IE_SHIFT		10
+#define XTMR_INJECT_IIR_ADDR_MASK	GENMASK(31, 16)
+
+#define XTMR_INJECT_MAGIC_MAX_VAL	255
+
+/**
+ * struct xtmr_inject_dev - Driver data for TMR Inject
+ * @regs: device physical base address
+ * @magic: Magic hardware configuration value
+ */
+struct xtmr_inject_dev {
+	void __iomem *regs;
+	u32 magic;
+};
+
+static DECLARE_FAULT_ATTR(inject_fault);
+static char *inject_request;
+module_param(inject_request, charp, 0);
+MODULE_PARM_DESC(inject_request, "default fault injection attributes");
+static struct dentry *dbgfs_root;
+
+/* IO accessors */
+static inline void xtmr_inject_write(struct xtmr_inject_dev *xtmr_inject,
+				     u32 addr, u32 value)
+{
+	iowrite32(value, xtmr_inject->regs + addr);
+}
+
+static inline u32 xtmr_inject_read(struct xtmr_inject_dev *xtmr_inject,
+				   u32 addr)
+{
+	return ioread32(xtmr_inject->regs + addr);
+}
+
+static int xtmr_inject_set(void *data, u64 val)
+{
+	if (val != 1)
+		return -EINVAL;
+
+	xmb_inject_err();
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(xtmr_inject_fops, NULL, xtmr_inject_set, "%llu\n");
+
+void xtmr_init_debugfs(struct xtmr_inject_dev *xtmr_inject)
+{
+	struct dentry *dir;
+
+	dbgfs_root = debugfs_create_dir("xtmr_inject", NULL);
+	dir = fault_create_debugfs_attr("inject_fault", dbgfs_root,
+					&inject_fault);
+	debugfs_create_file("inject_fault", 0200, dir, NULL,
+			    &xtmr_inject_fops);
+}
+
+static void xtmr_inject_init(struct xtmr_inject_dev *xtmr_inject)
+{
+	u32 cr_val;
+
+	if (inject_request)
+		setup_fault_attr(&inject_fault, inject_request);
+	/* Allow fault injection */
+	cr_val = xtmr_inject->magic |
+		 (1 << XTMR_INJECT_CR_IE_SHIFT) |
+		 (1 << XTMR_INJECT_CR_CPUID_SHIFT);
+	xtmr_inject_write(xtmr_inject, XTMR_INJECT_CR_OFFSET,
+			  cr_val);
+	/* Initialize the address inject and instruction inject registers */
+	xtmr_inject_write(xtmr_inject, XTMR_INJECT_AIR_OFFSET,
+			  XMB_INJECT_ERR_OFFSET);
+	xtmr_inject_write(xtmr_inject, XTMR_INJECT_IIR_OFFSET,
+			  XMB_INJECT_ERR_OFFSET & XTMR_INJECT_IIR_ADDR_MASK);
+}
+
+/**
+ * xtmr_inject_probe - Driver probe function
+ * @pdev: Pointer to the platform_device structure
+ *
+ * This is the driver probe routine. It does all the memory
+ * allocation and creates sysfs entries for the device.
+ *
+ * Return: 0 on success and failure value on error
+ */
+static int xtmr_inject_probe(struct platform_device *pdev)
+{
+	struct xtmr_inject_dev *xtmr_inject;
+	int err;
+
+	xtmr_inject = devm_kzalloc(&pdev->dev, sizeof(*xtmr_inject),
+				   GFP_KERNEL);
+	if (!xtmr_inject)
+		return -ENOMEM;
+
+	xtmr_inject->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(xtmr_inject->regs))
+		return PTR_ERR(xtmr_inject->regs);
+
+	err = of_property_read_u32(pdev->dev.of_node, "xlnx,magic",
+				   &xtmr_inject->magic);
+	if (err < 0) {
+		dev_err(&pdev->dev, "unable to read xlnx,magic property");
+		return err;
+	}
+
+	if (xtmr_inject->magic > XTMR_INJECT_MAGIC_MAX_VAL) {
+		dev_err(&pdev->dev, "invalid xlnx,magic property value");
+		return -EINVAL;
+	}
+
+	/* Initialize TMR Inject */
+	xtmr_inject_init(xtmr_inject);
+
+	xtmr_init_debugfs(xtmr_inject);
+
+	platform_set_drvdata(pdev, xtmr_inject);
+
+	return 0;
+}
+
+static int xtmr_inject_remove(struct platform_device *pdev)
+{
+	debugfs_remove_recursive(dbgfs_root);
+	dbgfs_root = NULL;
+	return 0;
+}
+
+static const struct of_device_id xtmr_inject_of_match[] = {
+	{
+		.compatible = "xlnx,tmr-inject-1.0",
+	},
+	{ /* end of table */ }
+};
+MODULE_DEVICE_TABLE(of, xtmr_inject_of_match);
+
+static struct platform_driver xtmr_inject_driver = {
+	.driver = {
+		.name = "xilinx-tmr_inject",
+		.of_match_table = xtmr_inject_of_match,
+	},
+	.probe = xtmr_inject_probe,
+	.remove = xtmr_inject_remove,
+};
+module_platform_driver(xtmr_inject_driver);
+MODULE_AUTHOR("Xilinx, Inc");
+MODULE_DESCRIPTION("Xilinx TMR Inject Driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1


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Re: [PATCH v4 2/4] drivers: misc: Add Support for TMR Manager

[Greg KH]

On Fri, Sep 09, 2022 at 11:49:14AM +0530, Appana Durga Kedareswara rao wrote:
> Triple Modular Redundancy(TMR) subsystem contains three microblaze cores,
> subsystem is fault-tolerant and continues to operate nominally after
> encountering an error. Together with the capability to detect and recover
> from errors, the implementation ensures the reliability of the entire
> subsystem.  TMR Manager is responsible for performing recovery of the
> subsystem detects the fault via a break signal it invokes microblaze
> software break handler which calls the tmr manager driver api to
> update the error count and status, added support for fault detection
> feature via sysfs interface.
> 
> Usage:
> To know the break handler count(Error count):
> cat /sys/devices/platform/amba_pl/44a10000.tmr_manager/errcnt
> 
> Signed-off-by: Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
> ---
> Changes for v4:
> --> None.
> Changes for v3:
> --> Corrected month in the sysfs-driver-xilinx-tmr-manager file
> --> Updated the Kconfig to compile the driver as a module
> --> Removed unneeded status sysfs attribute
> Changes for v2:
> --> Fixed Month in the sysfs description.
> --> Fixed line over 80 char in driver.
> --> Replaced kstrtol with kstrtoul as suggested by Michal.
> --> Added error check for xlnx,magic1 value.
> 
>  .../testing/sysfs-driver-xilinx-tmr-manager   |  16 ++
>  MAINTAINERS                                   |   7 +
>  drivers/misc/Kconfig                          |  10 +
>  drivers/misc/Makefile                         |   3 +-
>  drivers/misc/xilinx_tmr_manager.c             | 222 ++++++++++++++++++
>  5 files changed, 257 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
>  create mode 100644 drivers/misc/xilinx_tmr_manager.c
> 
> diff --git a/Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager b/Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
> new file mode 100644
> index 000000000000..2a97be6ae849
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
> @@ -0,0 +1,16 @@
> +What:		/sys/devices/platform/amba_pl/<dev>/errcnt
> +Date:		Sep 2022
> +Contact:	appana.durga.kedareswara.rao@amd.com
> +Description:	This control file provides the fault detection count.
> +		This file cannot be written.
> +		Example:
> +		# cat /sys/devices/platform/amba_pl/44a10000.tmr_manager/errcnt
> +		  1
> +
> +What:		/sys/devices/platform/amba_pl/<dev>/dis_block_break
> +Date:		Sep 2022
> +Contact:	appana.durga.kedareswara.rao@amd.com
> +Description:	Write any value to it, This control file enables the break signal.
> +		This file is write only.
> +		Example:
> +		# echo <any value> > /sys/devices/platform/amba_pl/44a10000.tmr_manager/dis_block_break
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f1390b8270b2..5fc5ec13985e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13277,6 +13277,13 @@ W:	http://www.monstr.eu/fdt/
>  T:	git git://git.monstr.eu/linux-2.6-microblaze.git
>  F:	arch/microblaze/
>  
> +MICROBLAZE TMR MANAGER
> +M:	Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
> +S:	Supported
> +F:	Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
> +F:	Documentation/devicetree/bindings/misc/xlnx,tmr-manager.yaml
> +F:	drivers/misc/xilinx_tmr_manager.c
> +
>  MICROCHIP AT91 DMA DRIVERS
>  M:	Ludovic Desroches <ludovic.desroches@microchip.com>
>  M:	Tudor Ambarus <tudor.ambarus@microchip.com>
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index 94e9fb4cdd76..1508cc29b05a 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -496,6 +496,16 @@ config VCPU_STALL_DETECTOR
>  
>  	  If you do not intend to run this kernel as a guest, say N.
>  
> +config TMR_MANAGER
> +	tristate "Select TMR Manager"
> +	depends on MICROBLAZE && MB_MANAGER
> +	help
> +	  This option enables the driver developed for TMR Manager. The Triple
> +	  Modular Redundancy(TMR) manager provides support for fault detection
> +	  via sysfs interface.

What is the module name?

And the fault detection api is in debugfs, not sysfs, right?

thanks,

greg k-h

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Re: [PATCH v4 2/4] drivers: misc: Add Support for TMR Manager

[Rao, Appana Durga Kedareswara]

Hi Greg,

Thanks for the review.

On 09/09/22 2:10 pm, Greg KH wrote:
> On Fri, Sep 09, 2022 at 11:49:14AM +0530, Appana Durga Kedareswara rao wrote:
>> Triple Modular Redundancy(TMR) subsystem contains three microblaze cores,
>> subsystem is fault-tolerant and continues to operate nominally after
>> encountering an error. Together with the capability to detect and recover
>> from errors, the implementation ensures the reliability of the entire
>> subsystem.  TMR Manager is responsible for performing recovery of the
>> subsystem detects the fault via a break signal it invokes microblaze
>> software break handler which calls the tmr manager driver api to
>> update the error count and status, added support for fault detection
>> feature via sysfs interface.
>>
>> Usage:
>> To know the break handler count(Error count):
>> cat /sys/devices/platform/amba_pl/44a10000.tmr_manager/errcnt
>>
>> Signed-off-by: Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
>> ---
>> Changes for v4:
>> --> None.
>> Changes for v3:
>> --> Corrected month in the sysfs-driver-xilinx-tmr-manager file
>> --> Updated the Kconfig to compile the driver as a module
>> --> Removed unneeded status sysfs attribute
>> Changes for v2:
>> --> Fixed Month in the sysfs description.
>> --> Fixed line over 80 char in driver.
>> --> Replaced kstrtol with kstrtoul as suggested by Michal.
>> --> Added error check for xlnx,magic1 value.
>>
>>   .../testing/sysfs-driver-xilinx-tmr-manager   |  16 ++
>>   MAINTAINERS                                   |   7 +
>>   drivers/misc/Kconfig                          |  10 +
>>   drivers/misc/Makefile                         |   3 +-
>>   drivers/misc/xilinx_tmr_manager.c             | 222 ++++++++++++++++++
>>   5 files changed, 257 insertions(+), 1 deletion(-)
>>   create mode 100644 Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
>>   create mode 100644 drivers/misc/xilinx_tmr_manager.c
>>
>> diff --git a/Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager b/Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
>> new file mode 100644
>> index 000000000000..2a97be6ae849
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
>> @@ -0,0 +1,16 @@
>> +What:		/sys/devices/platform/amba_pl/<dev>/errcnt
>> +Date:		Sep 2022
>> +Contact:	appana.durga.kedareswara.rao@amd.com
>> +Description:	This control file provides the fault detection count.
>> +		This file cannot be written.
>> +		Example:
>> +		# cat /sys/devices/platform/amba_pl/44a10000.tmr_manager/errcnt
>> +		  1
>> +
>> +What:		/sys/devices/platform/amba_pl/<dev>/dis_block_break
>> +Date:		Sep 2022
>> +Contact:	appana.durga.kedareswara.rao@amd.com
>> +Description:	Write any value to it, This control file enables the break signal.
>> +		This file is write only.
>> +		Example:
>> +		# echo <any value> > /sys/devices/platform/amba_pl/44a10000.tmr_manager/dis_block_break
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index f1390b8270b2..5fc5ec13985e 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -13277,6 +13277,13 @@ W:	http://www.monstr.eu/fdt/
>>   T:	git git://git.monstr.eu/linux-2.6-microblaze.git
>>   F:	arch/microblaze/
>>   
>> +MICROBLAZE TMR MANAGER
>> +M:	Appana Durga Kedareswara rao <appana.durga.kedareswara.rao@amd.com>
>> +S:	Supported
>> +F:	Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager
>> +F:	Documentation/devicetree/bindings/misc/xlnx,tmr-manager.yaml
>> +F:	drivers/misc/xilinx_tmr_manager.c
>> +
>>   MICROCHIP AT91 DMA DRIVERS
>>   M:	Ludovic Desroches <ludovic.desroches@microchip.com>
>>   M:	Tudor Ambarus <tudor.ambarus@microchip.com>
>> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
>> index 94e9fb4cdd76..1508cc29b05a 100644
>> --- a/drivers/misc/Kconfig
>> +++ b/drivers/misc/Kconfig
>> @@ -496,6 +496,16 @@ config VCPU_STALL_DETECTOR
>>   
>>   	  If you do not intend to run this kernel as a guest, say N.
>>   
>> +config TMR_MANAGER
>> +	tristate "Select TMR Manager"
>> +	depends on MICROBLAZE && MB_MANAGER
>> +	help
>> +	  This option enables the driver developed for TMR Manager. The Triple
>> +	  Modular Redundancy(TMR) manager provides support for fault detection
>> +	  via sysfs interface.
> 
> What is the module name?
> 
> And the fault detection api is in debugfs, not sysfs, right?

Fault injection happens via debugfs in the tmr-inject driver (4/4 patch 
- xilinx_tmr_inject.c) patch, Fault detection is tracked using tmr 
manager errcnt sysfs entry (/sys/devices/platform/amba_pl/<dev>/errcnt).
TMR Manager is responsible for performing recovery of the subsystem 
detects the fault via a break signal it invokes microblaze
software break handler which calls the tmr manager driver api to
update the error count.


Regards,
Kedar.
> 
> thanks,
> 
> greg k-h

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Re: [PATCH v4 2/4] drivers: misc: Add Support for TMR Manager

[kernel test robot]

Hi Appana,

I love your patch! Perhaps something to improve:

[auto build test WARNING on robh/for-next]
[also build test WARNING on soc/for-next linus/master v6.0-rc5]
[cannot apply to char-misc/char-misc-testing xilinx-xlnx/master next-20220915]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Appana-Durga-Kedareswara-rao/drivers-misc-Add-support-for-TMR-Manager-and-Inject-IPs/20220909-142639
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
reproduce:
        # https://github.com/intel-lab-lkp/linux/commit/fc425525cf8bef991de7374dd46cb69ed6b67961
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Appana-Durga-Kedareswara-rao/drivers-misc-Add-support-for-TMR-Manager-and-Inject-IPs/20220909-142639
        git checkout fc425525cf8bef991de7374dd46cb69ed6b67961
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        make htmldocs

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager:2: WARNING: Unexpected indentation.

vim +2 Documentation/ABI/testing/sysfs-driver-xilinx-tmr-manager

   > 2	Date:		Sep 2022
     3	Contact:	appana.durga.kedareswara.rao@amd.com
     4	Description:	This control file provides the fault detection count.
     5			This file cannot be written.
     6			Example:
     7			# cat /sys/devices/platform/amba_pl/44a10000.tmr_manager/errcnt
     8			  1
     9	

-- 
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