[PATCH v7 2/2] EDAC: al-mc-edac: Introduce Amazon's Annapurna Labs Memory Controller EDAC

[Talel Shenhar <talel@amazon.com>]

The Amazon's Annapurna Labs Memory Controller EDAC supports ECC capability
for error detection and correction (Single bit error correction, Double
detection). This driver introduces EDAC driver for that capability.

Signed-off-by: Talel Shenhar <talel@amazon.com>
Reviewed-by: James Morse <james.morse@arm.com>
---
 MAINTAINERS               |   7 +
 drivers/edac/Kconfig      |   7 +
 drivers/edac/Makefile     |   1 +
 drivers/edac/al_mc_edac.c | 354 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 369 insertions(+)
 create mode 100644 drivers/edac/al_mc_edac.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 296de2b51c83..ecd591d84bdf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -757,6 +757,13 @@ F:	drivers/tty/serial/altera_jtaguart.c
 F:	include/linux/altera_uart.h
 F:	include/linux/altera_jtaguart.h
 
+AMAZON ANNAPURNA LABS MEMORY CONTROLLER EDAC
+M:	Talel Shenhar <talel@amazon.com>
+M:	Talel Shenhar <talelshenhar@gmail.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/edac/amazon,al-mc-edac.yaml
+F:	drivers/edac/al_mc_edac.c
+
 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 417dad635526..8c7fb7338e75 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -100,6 +100,13 @@ config EDAC_AMD64_ERROR_INJECTION
 	  In addition, there are two control files, inject_read and inject_write,
 	  which trigger the DRAM ECC Read and Write respectively.
 
+config EDAC_AL_MC
+	tristate "Amazon's Annapurna Lab EDAC Memory Controller"
+	depends on (ARCH_ALPINE || COMPILE_TEST)
+	help
+	  Support for error detection and correction for Amazon's Annapurna
+	  Labs Alpine chips which allows 1 bit correction and 2 bits detection.
+
 config EDAC_AMD76X
 	tristate "AMD 76x (760, 762, 768)"
 	depends on PCI && X86_32
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index d77200c9680b..528832910ec4 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-$(CONFIG_EDAC_AL_MC)		+= al_mc_edac.o
 obj-$(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_mc_edac.c b/drivers/edac/al_mc_edac.c
new file mode 100644
index 000000000000..b0ee48775c62
--- /dev/null
+++ b/drivers/edac/al_mc_edac.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ */
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/edac.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include "edac_module.h"
+
+/* Registers Offset */
+#define AL_MC_ECC_CFG		0x70
+#define AL_MC_ECC_CLEAR		0x7c
+#define AL_MC_ECC_ERR_COUNT	0x80
+#define AL_MC_ECC_CE_ADDR0	0x84
+#define AL_MC_ECC_CE_ADDR1	0x88
+#define AL_MC_ECC_UE_ADDR0	0xa4
+#define AL_MC_ECC_UE_ADDR1	0xa8
+#define AL_MC_ECC_CE_SYND0	0x8c
+#define AL_MC_ECC_CE_SYND1	0x90
+#define AL_MC_ECC_CE_SYND2	0x94
+#define AL_MC_ECC_UE_SYND0	0xac
+#define AL_MC_ECC_UE_SYND1	0xb0
+#define AL_MC_ECC_UE_SYND2	0xb4
+
+/* Registers Fields */
+#define AL_MC_ECC_CFG_SCRUB_DISABLED	BIT(4)
+
+#define AL_MC_ECC_CLEAR_UE_COUNT	BIT(3)
+#define AL_MC_ECC_CLEAR_CE_COUNT	BIT(2)
+#define AL_MC_ECC_CLEAR_UE_ERR		BIT(1)
+#define AL_MC_ECC_CLEAR_CE_ERR		BIT(0)
+
+#define AL_MC_ECC_ERR_COUNT_UE		GENMASK(31, 16)
+#define AL_MC_ECC_ERR_COUNT_CE		GENMASK(15, 0)
+
+#define AL_MC_ECC_CE_ADDR0_RANK		GENMASK(25, 24)
+#define AL_MC_ECC_CE_ADDR0_ROW		GENMASK(17, 0)
+
+#define AL_MC_ECC_CE_ADDR1_BG		GENMASK(25, 24)
+#define AL_MC_ECC_CE_ADDR1_BANK		GENMASK(18, 16)
+#define AL_MC_ECC_CE_ADDR1_COLUMN	GENMASK(11, 0)
+
+#define AL_MC_ECC_UE_ADDR0_RANK		GENMASK(25, 24)
+#define AL_MC_ECC_UE_ADDR0_ROW		GENMASK(17, 0)
+
+#define AL_MC_ECC_UE_ADDR1_BG		GENMASK(25, 24)
+#define AL_MC_ECC_UE_ADDR1_BANK		GENMASK(18, 16)
+#define AL_MC_ECC_UE_ADDR1_COLUMN	GENMASK(11, 0)
+
+#define DRV_NAME "al_mc_edac"
+#define AL_MC_EDAC_MSG_MAX 256
+
+struct al_mc_edac {
+	void __iomem *mmio_base;
+	spinlock_t lock;
+	int irq_ce;
+	int irq_ue;
+};
+
+static void prepare_msg(char *message, size_t buffer_size,
+			enum hw_event_mc_err_type type,
+			u8 rank, u32 row, u8 bg, u8 bank, u16 column,
+			u32 syn0, u32 syn1, u32 syn2)
+{
+	snprintf(message, buffer_size,
+		 "%s rank=0x%x row=0x%x bg=0x%x bank=0x%x col=0x%x syn0: 0x%x syn1: 0x%x syn2: 0x%x",
+		 type == HW_EVENT_ERR_UNCORRECTED ? "UE" : "CE",
+		 rank, row, bg, bank, column, syn0, syn1, syn2);
+}
+
+static int handle_ce(struct mem_ctl_info *mci)
+{
+	u32 eccerrcnt, ecccaddr0, ecccaddr1, ecccsyn0, ecccsyn1, ecccsyn2, row;
+	struct al_mc_edac *al_mc = mci->pvt_info;
+	char msg[AL_MC_EDAC_MSG_MAX];
+	u16 ce_count, column;
+	unsigned long flags;
+	u8 rank, bg, bank;
+
+	eccerrcnt = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_ERR_COUNT);
+	ce_count = FIELD_GET(AL_MC_ECC_ERR_COUNT_CE, eccerrcnt);
+	if (!ce_count)
+		return 0;
+
+	ecccaddr0 = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_CE_ADDR0);
+	ecccaddr1 = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_CE_ADDR1);
+	ecccsyn0 = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_CE_SYND0);
+	ecccsyn1 = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_CE_SYND1);
+	ecccsyn2 = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_CE_SYND2);
+
+	writel_relaxed(AL_MC_ECC_CLEAR_CE_COUNT | AL_MC_ECC_CLEAR_CE_ERR,
+		       al_mc->mmio_base + AL_MC_ECC_CLEAR);
+
+	dev_dbg(mci->pdev, "eccuaddr0=0x%08x eccuaddr1=0x%08x\n",
+		ecccaddr0, ecccaddr1);
+
+	rank = FIELD_GET(AL_MC_ECC_CE_ADDR0_RANK, ecccaddr0);
+	row = FIELD_GET(AL_MC_ECC_CE_ADDR0_ROW, ecccaddr0);
+
+	bg = FIELD_GET(AL_MC_ECC_CE_ADDR1_BG, ecccaddr1);
+	bank = FIELD_GET(AL_MC_ECC_CE_ADDR1_BANK, ecccaddr1);
+	column = FIELD_GET(AL_MC_ECC_CE_ADDR1_COLUMN, ecccaddr1);
+
+	prepare_msg(msg, sizeof(msg), HW_EVENT_ERR_CORRECTED,
+		    rank, row, bg, bank, column,
+		    ecccsyn0, ecccsyn1, ecccsyn2);
+
+	spin_lock_irqsave(&al_mc->lock, flags);
+	edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci,
+			     ce_count, 0, 0, 0, 0, 0, -1, mci->ctl_name, msg);
+	spin_unlock_irqrestore(&al_mc->lock, flags);
+
+	return ce_count;
+}
+
+static int handle_ue(struct mem_ctl_info *mci)
+{
+	u32 eccerrcnt, eccuaddr0, eccuaddr1, eccusyn0, eccusyn1, eccusyn2, row;
+	struct al_mc_edac *al_mc = mci->pvt_info;
+	char msg[AL_MC_EDAC_MSG_MAX];
+	u16 ue_count, column;
+	unsigned long flags;
+	u8 rank, bg, bank;
+
+	eccerrcnt = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_ERR_COUNT);
+	ue_count = FIELD_GET(AL_MC_ECC_ERR_COUNT_UE, eccerrcnt);
+	if (!ue_count)
+		return 0;
+
+	eccuaddr0 = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_UE_ADDR0);
+	eccuaddr1 = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_UE_ADDR1);
+	eccusyn0 = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_UE_SYND0);
+	eccusyn1 = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_UE_SYND1);
+	eccusyn2 = readl_relaxed(al_mc->mmio_base + AL_MC_ECC_UE_SYND2);
+
+	writel_relaxed(AL_MC_ECC_CLEAR_UE_COUNT | AL_MC_ECC_CLEAR_UE_ERR,
+		       al_mc->mmio_base + AL_MC_ECC_CLEAR);
+
+	dev_dbg(mci->pdev, "eccuaddr0=0x%08x eccuaddr1=0x%08x\n",
+		eccuaddr0, eccuaddr1);
+
+	rank = FIELD_GET(AL_MC_ECC_UE_ADDR0_RANK, eccuaddr0);
+	row = FIELD_GET(AL_MC_ECC_UE_ADDR0_ROW, eccuaddr0);
+
+	bg = FIELD_GET(AL_MC_ECC_UE_ADDR1_BG, eccuaddr1);
+	bank = FIELD_GET(AL_MC_ECC_UE_ADDR1_BANK, eccuaddr1);
+	column = FIELD_GET(AL_MC_ECC_UE_ADDR1_COLUMN, eccuaddr1);
+
+	prepare_msg(msg, sizeof(msg), HW_EVENT_ERR_UNCORRECTED,
+		    rank, row, bg, bank, column,
+		    eccusyn0, eccusyn1, eccusyn2);
+
+	spin_lock_irqsave(&al_mc->lock, flags);
+	edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci,
+			     ue_count, 0, 0, 0, 0, 0, -1, mci->ctl_name, msg);
+	spin_unlock_irqrestore(&al_mc->lock, flags);
+
+	return ue_count;
+}
+
+static void al_mc_edac_check(struct mem_ctl_info *mci)
+{
+	struct al_mc_edac *al_mc = mci->pvt_info;
+
+	if (al_mc->irq_ue <= 0)
+		handle_ue(mci);
+
+	if (al_mc->irq_ce <= 0)
+		handle_ce(mci);
+}
+
+static irqreturn_t al_mc_edac_irq_handler_ue(int irq, void *info)
+{
+	struct platform_device *pdev = info;
+	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
+
+	if (handle_ue(mci))
+		return IRQ_HANDLED;
+	return IRQ_NONE;
+}
+
+static irqreturn_t al_mc_edac_irq_handler_ce(int irq, void *info)
+{
+	struct platform_device *pdev = info;
+	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
+
+	if (handle_ce(mci))
+		return IRQ_HANDLED;
+	return IRQ_NONE;
+}
+
+static enum scrub_type al_mc_edac_get_scrub_mode(void __iomem *mmio_base)
+{
+	u32 ecccfg0;
+
+	ecccfg0 = readl(mmio_base + AL_MC_ECC_CFG);
+
+	if (FIELD_GET(AL_MC_ECC_CFG_SCRUB_DISABLED, ecccfg0))
+		return SCRUB_NONE;
+	else
+		return SCRUB_HW_SRC;
+}
+
+static void devm_al_mc_edac_free(void *data)
+{
+	edac_mc_free(data);
+}
+
+static void devm_al_mc_edac_del(void *data)
+{
+	edac_mc_del_mc(data);
+}
+
+static int al_mc_edac_probe(struct platform_device *pdev)
+{
+	struct edac_mc_layer layers[1];
+	struct mem_ctl_info *mci;
+	struct al_mc_edac *al_mc;
+	void __iomem *mmio_base;
+	struct dimm_info *dimm;
+	int ret;
+
+	mmio_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mmio_base)) {
+		dev_err(&pdev->dev, "failed to ioremap memory (%ld)\n",
+			PTR_ERR(mmio_base));
+		return PTR_ERR(mmio_base);
+	}
+
+	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
+	layers[0].size = 1;
+	layers[0].is_virt_csrow = false;
+	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers,
+			    sizeof(struct al_mc_edac));
+	if (!mci)
+		return -ENOMEM;
+
+	ret = devm_add_action(&pdev->dev, devm_al_mc_edac_free, mci);
+	if (ret) {
+		edac_mc_free(mci);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, mci);
+	al_mc = mci->pvt_info;
+
+	al_mc->mmio_base = mmio_base;
+
+	al_mc->irq_ue = of_irq_get_byname(pdev->dev.of_node, "ue");
+	if (al_mc->irq_ue <= 0)
+		dev_dbg(&pdev->dev,
+			"no IRQ defined for UE - falling back to polling\n");
+
+	al_mc->irq_ce = of_irq_get_byname(pdev->dev.of_node, "ce");
+	if (al_mc->irq_ce <= 0)
+		dev_dbg(&pdev->dev,
+			"no IRQ defined for CE - falling back to polling\n");
+
+	/*
+	 * In case both interrupts (ue/ce) are to be found, use interrupt mode.
+	 * In case none of the interrupt are foud, use polling mode.
+	 * In case only one interrupt is found, use interrupt mode for it but
+	 * keep polling mode enable for the other.
+	 */
+	if (al_mc->irq_ue <= 0 || al_mc->irq_ce <= 0) {
+		edac_op_state = EDAC_OPSTATE_POLL;
+		mci->edac_check = al_mc_edac_check;
+	} else {
+		edac_op_state = EDAC_OPSTATE_INT;
+	}
+
+	spin_lock_init(&al_mc->lock);
+
+	mci->mtype_cap = MEM_FLAG_DDR3 | MEM_FLAG_DDR4;
+	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
+	mci->edac_cap = EDAC_FLAG_SECDED;
+	mci->mod_name = DRV_NAME;
+	mci->ctl_name = "al_mc";
+	mci->pdev = &pdev->dev;
+	mci->scrub_mode = al_mc_edac_get_scrub_mode(mmio_base);
+
+	dimm = *mci->dimms;
+	dimm->grain = 1;
+
+	ret = edac_mc_add_mc(mci);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"fail to add memory controller device (%d)\n",
+			ret);
+		return ret;
+	}
+
+	ret = devm_add_action(&pdev->dev, devm_al_mc_edac_del, &pdev->dev);
+	if (ret) {
+		edac_mc_del_mc(&pdev->dev);
+		return ret;
+	}
+
+	if (al_mc->irq_ue > 0) {
+		ret = devm_request_irq(&pdev->dev,
+				       al_mc->irq_ue,
+				       al_mc_edac_irq_handler_ue,
+				       IRQF_SHARED,
+				       pdev->name,
+				       pdev);
+		if (ret != 0) {
+			dev_err(&pdev->dev,
+				"failed to request UE IRQ %d (%d)\n",
+				al_mc->irq_ue, ret);
+			return ret;
+		}
+	}
+
+	if (al_mc->irq_ce > 0) {
+		ret = devm_request_irq(&pdev->dev,
+				       al_mc->irq_ce,
+				       al_mc_edac_irq_handler_ce,
+				       IRQF_SHARED,
+				       pdev->name,
+				       pdev);
+		if (ret != 0) {
+			dev_err(&pdev->dev,
+				"failed to request CE IRQ %d (%d)\n",
+				al_mc->irq_ce, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static const struct of_device_id al_mc_edac_of_match[] = {
+	{ .compatible = "amazon,al-mc-edac", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, al_mc_edac_of_match);
+
+static struct platform_driver al_mc_edac_driver = {
+	.probe = al_mc_edac_probe,
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = al_mc_edac_of_match,
+	},
+};
+
+module_platform_driver(al_mc_edac_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Talel Shenhar");
+MODULE_DESCRIPTION("Amazon's Annapurna Lab's Memory Controller EDAC Driver");
-- 
2.17.1