EDAC/al-mc-edac: Add Amazon's Annapurna Labs Memory Controller driver

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.

[ bp: Remove "EDAC" string from Kconfig tristate as it is redundant. ]

Signed-off-by: Talel Shenhar <[e-mail]>
Signed-off-by: Borislav Petkov <[e-mail]>
Reviewed-by: James Morse <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]

MAINTAINERS

···
 F:	Documentation/devicetree/bindings/interrupt-controller/amazon,al-fic.txt
 F:	drivers/irqchip/irq-al-fic.c
 
+AMAZON ANNAPURNA LABS MEMORY CONTROLLER EDAC
+M:	Talel Shenhar <[e-mail]>
+M:	Talel Shenhar <[e-mail]>
+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 <[e-mail]>
 S:	Maintained

drivers/edac/Kconfig

···
 	  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 Memory Controller"
+	depends on (ARCH_ALPINE || COMPILE_TEST)
+	help
+	  Support for error detection and correction for Amazon's Annapurna
+	  Labs Alpine chips which allow 1 bit correction and 2 bits detection.
+
 config EDAC_AMD76X
 	tristate "AMD 76x (760, 762, 768)"
 	depends on PCI && X86_32

drivers/edac/Makefile

···
 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

drivers/edac/al_mc_edac.c

···
+// 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 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 = 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");