[PATCH v3 2/4] edac: Add support for Amazon's Annapurna Labs L1 EDAC

[Hanna Hawa <hhhawa@amazon.com>]

Adds support for Amazon's Annapurna Labs L1 EDAC driver to detect and
report L1 errors.

Signed-off-by: Hanna Hawa <hhhawa@amazon.com>
---
 MAINTAINERS               |   6 ++
 drivers/edac/Kconfig      |   8 +++
 drivers/edac/Makefile     |   1 +
 drivers/edac/al_l1_edac.c | 156 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 171 insertions(+)
 create mode 100644 drivers/edac/al_l1_edac.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 77eae44..fd29ea6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -743,6 +743,12 @@ F:	drivers/tty/serial/altera_jtaguart.c
 F:	include/linux/altera_uart.h
 F:	include/linux/altera_jtaguart.h
 
+AMAZON ANNAPURNA LABS L1 EDAC
+M:	Hanna Hawa <hhhawa@amazon.com>
+S:	Maintained
+F:	drivers/edac/al_l1_edac.c
+F:	Documentation/devicetree/bindings/edac/amazon,al-l1-edac.txt
+
 AMAZON ANNAPURNA LABS THERMAL MMIO DRIVER
 M:	Talel Shenhar <talel@amazon.com>
 S:	Maintained
diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 200c04c..58b92bc 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -74,6 +74,14 @@ config EDAC_GHES
 
 	  In doubt, say 'Y'.
 
+config EDAC_AL_L1
+	bool "Amazon's Annapurna Labs L1 EDAC"
+	depends on ARCH_ALPINE
+	help
+	  Support for L1 error detection and correction
+	  for Amazon's Annapurna Labs SoCs.
+	  This driver detects errors of L1 caches.
+
 config EDAC_AMD64
 	tristate "AMD64 (Opteron, Athlon64)"
 	depends on AMD_NB && EDAC_DECODE_MCE
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index 165ca65e..caa2dc9 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_EDAC_GHES)			+= ghes_edac.o
 edac_mce_amd-y				:= mce_amd.o
 obj-$(CONFIG_EDAC_DECODE_MCE)		+= edac_mce_amd.o
 
+obj-$(CONFIG_EDAC_AL_L1)		+= al_l1_edac.o
 obj-$(CONFIG_EDAC_AMD76X)		+= amd76x_edac.o
 obj-$(CONFIG_EDAC_CPC925)		+= cpc925_edac.o
 obj-$(CONFIG_EDAC_I5000)		+= i5000_edac.o
diff --git a/drivers/edac/al_l1_edac.c b/drivers/edac/al_l1_edac.c
new file mode 100644
index 0000000..70510ea
--- /dev/null
+++ b/drivers/edac/al_l1_edac.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ */
+
+#include <linux/bitfield.h>
+
+#include "edac_device.h"
+#include "edac_module.h"
+
+#define DRV_NAME				"al_l1_edac"
+
+/* Same bit assignments of CPUMERRSR_EL1 in ARM CA57/CA72 */
+#define ARM_CA57_CPUMERRSR_EL1			sys_reg(3, 1, 15, 2, 2)
+#define ARM_CA57_CPUMERRSR_RAM_ID		GENMASK(30, 24)
+#define  ARM_CA57_L1_I_TAG_RAM			0x00
+#define  ARM_CA57_L1_I_DATA_RAM			0x01
+#define  ARM_CA57_L1_D_TAG_RAM			0x08
+#define  ARM_CA57_L1_D_DATA_RAM			0x09
+#define  ARM_CA57_L2_TLB_RAM			0x18
+#define ARM_CA57_CPUMERRSR_VALID		BIT(31)
+#define ARM_CA57_CPUMERRSR_REPEAT		GENMASK_ULL(39, 32)
+#define ARM_CA57_CPUMERRSR_OTHER		GENMASK_ULL(47, 40)
+#define ARM_CA57_CPUMERRSR_FATAL		BIT_ULL(63)
+
+#define AL_L1_EDAC_MSG_MAX			256
+
+static void al_l1_edac_cpumerrsr(void *arg)
+{
+	struct edac_device_ctl_info *edac_dev = arg;
+	int cpu, i;
+	u32 ramid, repeat, other, fatal;
+	u64 val = read_sysreg_s(ARM_CA57_CPUMERRSR_EL1);
+	char msg[AL_L1_EDAC_MSG_MAX];
+	int space, count;
+	char *p;
+
+	if (!(FIELD_GET(ARM_CA57_CPUMERRSR_VALID, val)))
+		return;
+
+	cpu = smp_processor_id();
+	ramid = FIELD_GET(ARM_CA57_CPUMERRSR_RAM_ID, val);
+	repeat = FIELD_GET(ARM_CA57_CPUMERRSR_REPEAT, val);
+	other = FIELD_GET(ARM_CA57_CPUMERRSR_OTHER, val);
+	fatal = FIELD_GET(ARM_CA57_CPUMERRSR_FATAL, val);
+
+	space = sizeof(msg);
+	p = msg;
+	count = snprintf(p, space, "CPU%d L1 %serror detected", cpu,
+			 (fatal) ? "Fatal " : "");
+	p += count;
+	space -= count;
+
+	switch (ramid) {
+	case ARM_CA57_L1_I_TAG_RAM:
+		count = snprintf(p, space, " RAMID='L1-I Tag RAM'");
+		break;
+	case ARM_CA57_L1_I_DATA_RAM:
+		count = snprintf(p, space, " RAMID='L1-I Data RAM'");
+		break;
+	case ARM_CA57_L1_D_TAG_RAM:
+		count = snprintf(p, space, " RAMID='L1-D Tag RAM'");
+		break;
+	case ARM_CA57_L1_D_DATA_RAM:
+		count = snprintf(p, space, " RAMID='L1-D Data RAM'");
+		break;
+	case ARM_CA57_L2_TLB_RAM:
+		count = snprintf(p, space, " RAMID='L2 TLB RAM'");
+		break;
+	default:
+		count = snprintf(p, space, " RAMID='unknown'");
+		break;
+	}
+
+	p += count;
+	space -= count;
+	count = snprintf(p, space,
+			 " repeat=%d, other=%d (CPUMERRSR_EL1=0x%llx)",
+			 repeat, other, val);
+
+	for (i = 0; i < repeat; i++) {
+		if (fatal)
+			edac_device_handle_ue(edac_dev, 0, 0, msg);
+		else
+			edac_device_handle_ce(edac_dev, 0, 0, msg);
+	}
+
+	write_sysreg_s(0, ARM_CA57_CPUMERRSR_EL1);
+}
+
+static void al_l1_edac_check(struct edac_device_ctl_info *edac_dev)
+{
+	on_each_cpu(al_l1_edac_cpumerrsr, edac_dev, 1);
+}
+
+static int al_l1_edac_probe(struct platform_device *pdev)
+{
+	struct edac_device_ctl_info *edac_dev;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	edac_dev = edac_device_alloc_ctl_info(0, (char *)dev_name(dev), 1, "L",
+					      1, 1, NULL, 0,
+					      edac_device_alloc_index());
+	if (IS_ERR(edac_dev))
+		return -ENOMEM;
+
+	edac_dev->edac_check = al_l1_edac_check;
+	edac_dev->dev = dev;
+	edac_dev->mod_name = DRV_NAME;
+	edac_dev->dev_name = dev_name(dev);
+	edac_dev->ctl_name = "L1 cache";
+	platform_set_drvdata(pdev, edac_dev);
+
+	ret = edac_device_add_device(edac_dev);
+	if (ret) {
+		dev_err(dev, "Failed to add L1 edac device\n");
+		goto err;
+	}
+
+	return 0;
+err:
+	edac_device_free_ctl_info(edac_dev);
+
+	return ret;
+}
+
+static int al_l1_edac_remove(struct platform_device *pdev)
+{
+	struct edac_device_ctl_info *edac_dev = platform_get_drvdata(pdev);
+
+	edac_device_del_device(edac_dev->dev);
+	edac_device_free_ctl_info(edac_dev);
+
+	return 0;
+}
+
+static const struct of_device_id al_l1_edac_of_match[] = {
+	{ .compatible = "amazon,al-l1-edac" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, al_l1_edac_of_match);
+
+static struct platform_driver al_l1_edac_driver = {
+	.probe = al_l1_edac_probe,
+	.remove = al_l1_edac_remove,
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = al_l1_edac_of_match,
+	},
+};
+module_platform_driver(al_l1_edac_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Hanna Hawa <hhhawa@amazon.com>");
+MODULE_DESCRIPTION("Amazon's Annapurna Lab's L1 EDAC Driver");
-- 
2.7.4