--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx ZynqMP OCM ECC Driver
+ *
+ * Copyright (C) 2022 Advanced Micro Devices, Inc.
+ */
+
+#include <linux/edac.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include "edac_module.h"
+
+#define ZYNQMP_OCM_EDAC_MSG_SIZE 256
+
+#define ZYNQMP_OCM_EDAC_STRING "zynqmp_ocm"
+
+/* Error/Interrupt registers */
+#define ERR_CTRL_OFST 0x0
+#define OCM_ISR_OFST 0x04
+#define OCM_IMR_OFST 0x08
+#define OCM_IEN_OFST 0x0C
+#define OCM_IDS_OFST 0x10
+
+/* ECC control register */
+#define ECC_CTRL_OFST 0x14
+
+/* Correctable error info registers */
+#define CE_FFA_OFST 0x1C
+#define CE_FFD0_OFST 0x20
+#define CE_FFD1_OFST 0x24
+#define CE_FFD2_OFST 0x28
+#define CE_FFD3_OFST 0x2C
+#define CE_FFE_OFST 0x30
+
+/* Uncorrectable error info registers */
+#define UE_FFA_OFST 0x34
+#define UE_FFD0_OFST 0x38
+#define UE_FFD1_OFST 0x3C
+#define UE_FFD2_OFST 0x40
+#define UE_FFD3_OFST 0x44
+#define UE_FFE_OFST 0x48
+
+/* ECC control register bit field definitions */
+#define ECC_CTRL_CLR_CE_ERR 0x40
+#define ECC_CTRL_CLR_UE_ERR 0x80
+
+/* Fault injection data and count registers */
+#define OCM_FID0_OFST 0x4C
+#define OCM_FID1_OFST 0x50
+#define OCM_FID2_OFST 0x54
+#define OCM_FID3_OFST 0x58
+#define OCM_FIC_OFST 0x74
+
+#define UE_MAX_BITPOS_LOWER 31
+#define UE_MIN_BITPOS_UPPER 32
+#define UE_MAX_BITPOS_UPPER 63
+
+/* Interrupt masks */
+#define OCM_CEINTR_MASK BIT(6)
+#define OCM_UEINTR_MASK BIT(7)
+#define OCM_ECC_ENABLE_MASK BIT(0)
+
+#define OCM_FICOUNT_MASK GENMASK(23, 0)
+#define OCM_NUM_UE_BITPOS 2
+#define OCM_BASEVAL 0xFFFC0000
+#define EDAC_DEVICE "ZynqMP-OCM"
+
+/**
+ * struct ecc_error_info - ECC error log information
+ * @addr: Fault generated at this address
+ * @fault_lo: Generated fault data (lower 32-bit)
+ * @fault_hi: Generated fault data (upper 32-bit)
+ */
+struct ecc_error_info {
+ u32 addr;
+ u32 fault_lo;
+ u32 fault_hi;
+};
+
+/**
+ * struct ecc_status - ECC status information to report
+ * @ce_cnt: Correctable error count
+ * @ue_cnt: Uncorrectable error count
+ * @ceinfo: Correctable error log information
+ * @ueinfo: Uncorrectable error log information
+ */
+struct ecc_status {
+ u32 ce_cnt;
+ u32 ue_cnt;
+ struct ecc_error_info ceinfo;
+ struct ecc_error_info ueinfo;
+};
+
+/**
+ * struct edac_priv - OCM private instance data
+ * @baseaddr: Base address of the OCM
+ * @message: Buffer for framing the event specific info
+ * @stat: ECC status information
+ * @ce_cnt: Correctable Error count
+ * @ue_cnt: Uncorrectable Error count
+ * @debugfs_dir: Directory entry for debugfs
+ * @ce_bitpos: Bit position for Correctable Error
+ * @ue_bitpos: Array to store UnCorrectable Error bit positions
+ * @fault_injection_cnt: Fault Injection Counter value
+ */
+struct edac_priv {
+ void __iomem *baseaddr;
+ char message[ZYNQMP_OCM_EDAC_MSG_SIZE];
+ struct ecc_status stat;
+ u32 ce_cnt;
+ u32 ue_cnt;
+#ifdef CONFIG_EDAC_DEBUG
+ struct dentry *debugfs_dir;
+ u8 ce_bitpos;
+ u8 ue_bitpos[OCM_NUM_UE_BITPOS];
+ u32 fault_injection_cnt;
+#endif
+};
+
+/**
+ * get_error_info - Get the current ECC error info
+ * @base: Pointer to the base address of the OCM
+ * @p: Pointer to the OCM ECC status structure
+ * @mask: Status register mask value
+ *
+ * Determines there is any ECC error or not
+ *
+ */
+static void get_error_info(void __iomem *base, struct ecc_status *p, int mask)
+{
+ if (mask & OCM_CEINTR_MASK) {
+ p->ce_cnt++;
+ p->ceinfo.fault_lo = readl(base + CE_FFD0_OFST);
+ p->ceinfo.fault_hi = readl(base + CE_FFD1_OFST);
+ p->ceinfo.addr = (OCM_BASEVAL | readl(base + CE_FFA_OFST));
+ writel(ECC_CTRL_CLR_CE_ERR, base + OCM_ISR_OFST);
+ } else if (mask & OCM_UEINTR_MASK) {
+ p->ue_cnt++;
+ p->ueinfo.fault_lo = readl(base + UE_FFD0_OFST);
+ p->ueinfo.fault_hi = readl(base + UE_FFD1_OFST);
+ p->ueinfo.addr = (OCM_BASEVAL | readl(base + UE_FFA_OFST));
+ writel(ECC_CTRL_CLR_UE_ERR, base + OCM_ISR_OFST);
+ }
+}
+
+/**
+ * handle_error - Handle error types CE and UE
+ * @dci: Pointer to the EDAC device instance
+ * @p: Pointer to the OCM ECC status structure
+ *
+ * Handles correctable and uncorrectable errors.
+ */
+static void handle_error(struct edac_device_ctl_info *dci, struct ecc_status *p)
+{
+ struct edac_priv *priv = dci->pvt_info;
+ struct ecc_error_info *pinf;
+
+ if (p->ce_cnt) {
+ pinf = &p->ceinfo;
+ snprintf(priv->message, ZYNQMP_OCM_EDAC_MSG_SIZE,
+ "\nOCM ECC error type :%s\nAddr: [0x%x]\nFault Data[0x%08x%08x]",
+ "CE", pinf->addr, pinf->fault_hi, pinf->fault_lo);
+ edac_device_handle_ce(dci, 0, 0, priv->message);
+ }
+
+ if (p->ue_cnt) {
+ pinf = &p->ueinfo;
+ snprintf(priv->message, ZYNQMP_OCM_EDAC_MSG_SIZE,
+ "\nOCM ECC error type :%s\nAddr: [0x%x]\nFault Data[0x%08x%08x]",
+ "UE", pinf->addr, pinf->fault_hi, pinf->fault_lo);
+ edac_device_handle_ue(dci, 0, 0, priv->message);
+ }
+
+ memset(p, 0, sizeof(*p));
+}
+
+/**
+ * intr_handler - ISR routine
+ * @irq: irq number
+ * @dev_id: device id pointer
+ *
+ * Return: IRQ_NONE, if CE/UE interrupt not set or IRQ_HANDLED otherwise
+ */
+static irqreturn_t intr_handler(int irq, void *dev_id)
+{
+ struct edac_device_ctl_info *dci = dev_id;
+ struct edac_priv *priv = dci->pvt_info;
+ int regval;
+
+ regval = readl(priv->baseaddr + OCM_ISR_OFST);
+ if (!(regval & (OCM_CEINTR_MASK | OCM_UEINTR_MASK))) {
+ WARN_ONCE(1, "Unhandled IRQ%d, ISR: 0x%x", irq, regval);
+ return IRQ_NONE;
+ }
+
+ get_error_info(priv->baseaddr, &priv->stat, regval);
+
+ priv->ce_cnt += priv->stat.ce_cnt;
+ priv->ue_cnt += priv->stat.ue_cnt;
+ handle_error(dci, &priv->stat);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * get_eccstate - Return the ECC status
+ * @base: Pointer to the OCM base address
+ *
+ * Get the ECC enable/disable status
+ *
+ * Return: ECC status 0/1.
+ */
+static bool get_eccstate(void __iomem *base)
+{
+ return readl(base + ECC_CTRL_OFST) & OCM_ECC_ENABLE_MASK;
+}
+
+#ifdef CONFIG_EDAC_DEBUG
+/**
+ * write_fault_count - write fault injection count
+ * @priv: Pointer to the EDAC private struct
+ *
+ * Update the fault injection count register, once the counter reaches
+ * zero, it injects errors
+ */
+static void write_fault_count(struct edac_priv *priv)
+{
+ u32 ficount = priv->fault_injection_cnt;
+
+ if (ficount & ~OCM_FICOUNT_MASK) {
+ ficount &= OCM_FICOUNT_MASK;
+ edac_printk(KERN_INFO, EDAC_DEVICE,
+ "Fault injection count value truncated to %d\n", ficount);
+ }
+
+ writel(ficount, priv->baseaddr + OCM_FIC_OFST);
+}
+
+/*
+ * To get the Correctable Error injected, the following steps are needed:
+ * - Setup the optional Fault Injection Count:
+ * echo <fault_count val> > /sys/kernel/debug/edac/ocm/inject_fault_count
+ * - Write the Correctable Error bit position value:
+ * echo <bit_pos val> > /sys/kernel/debug/edac/ocm/inject_ce_bitpos
+ */
+static ssize_t inject_ce_write(struct file *file, const char __user *data,
+ size_t count, loff_t *ppos)
+{
+ struct edac_device_ctl_info *edac_dev = file->private_data;
+ struct edac_priv *priv = edac_dev->pvt_info;
+ int ret;
+
+ if (!data)
+ return -EFAULT;
+
+ ret = kstrtou8_from_user(data, count, 0, &priv->ce_bitpos);
+ if (ret)
+ return ret;
+
+ if (priv->ce_bitpos > UE_MAX_BITPOS_UPPER)
+ return -EINVAL;
+
+ if (priv->ce_bitpos <= UE_MAX_BITPOS_LOWER) {
+ writel(BIT(priv->ce_bitpos), priv->baseaddr + OCM_FID0_OFST);
+ writel(0, priv->baseaddr + OCM_FID1_OFST);
+ } else {
+ writel(BIT(priv->ce_bitpos - UE_MIN_BITPOS_UPPER),
+ priv->baseaddr + OCM_FID1_OFST);
+ writel(0, priv->baseaddr + OCM_FID0_OFST);
+ }
+
+ write_fault_count(priv);
+
+ return count;
+}
+
+static const struct file_operations inject_ce_fops = {
+ .open = simple_open,
+ .write = inject_ce_write,
+ .llseek = generic_file_llseek,
+};
+
+/*
+ * To get the Uncorrectable Error injected, the following steps are needed:
+ * - Setup the optional Fault Injection Count:
+ * echo <fault_count val> > /sys/kernel/debug/edac/ocm/inject_fault_count
+ * - Write the Uncorrectable Error bit position values:
+ * echo <bit_pos0 val>,<bit_pos1 val> > /sys/kernel/debug/edac/ocm/inject_ue_bitpos
+ */
+static ssize_t inject_ue_write(struct file *file, const char __user *data,
+ size_t count, loff_t *ppos)
+{
+ struct edac_device_ctl_info *edac_dev = file->private_data;
+ struct edac_priv *priv = edac_dev->pvt_info;
+ char buf[6], *pbuf, *token[2];
+ u64 ue_bitpos;
+ int i, ret;
+ u8 len;
+
+ if (!data)
+ return -EFAULT;
+
+ len = min_t(size_t, count, sizeof(buf));
+ if (copy_from_user(buf, data, len))
+ return -EFAULT;
+
+ buf[len] = '\0';
+ pbuf = &buf[0];
+ for (i = 0; i < OCM_NUM_UE_BITPOS; i++)
+ token[i] = strsep(&pbuf, ",");
+
+ ret = kstrtou8(token[0], 0, &priv->ue_bitpos[0]);
+ if (ret)
+ return ret;
+
+ ret = kstrtou8(token[1], 0, &priv->ue_bitpos[1]);
+ if (ret)
+ return ret;
+
+ if (priv->ue_bitpos[0] > UE_MAX_BITPOS_UPPER ||
+ priv->ue_bitpos[1] > UE_MAX_BITPOS_UPPER)
+ return -EINVAL;
+
+ if (priv->ue_bitpos[0] == priv->ue_bitpos[1]) {
+ edac_printk(KERN_ERR, EDAC_DEVICE, "Bit positions should not be equal\n");
+ return -EINVAL;
+ }
+
+ ue_bitpos = BIT(priv->ue_bitpos[0]) | BIT(priv->ue_bitpos[1]);
+
+ writel((u32)ue_bitpos, priv->baseaddr + OCM_FID0_OFST);
+ writel((u32)(ue_bitpos >> 32), priv->baseaddr + OCM_FID1_OFST);
+
+ write_fault_count(priv);
+
+ return count;
+}
+
+static const struct file_operations inject_ue_fops = {
+ .open = simple_open,
+ .write = inject_ue_write,
+ .llseek = generic_file_llseek,
+};
+
+static void setup_debugfs(struct edac_device_ctl_info *edac_dev)
+{
+ struct edac_priv *priv = edac_dev->pvt_info;
+
+ priv->debugfs_dir = edac_debugfs_create_dir("ocm");
+ if (!priv->debugfs_dir)
+ return;
+
+ edac_debugfs_create_x32("inject_fault_count", 0644, priv->debugfs_dir,
+ &priv->fault_injection_cnt);
+ edac_debugfs_create_file("inject_ue_bitpos", 0644, priv->debugfs_dir,
+ edac_dev, &inject_ue_fops);
+ edac_debugfs_create_file("inject_ce_bitpos", 0644, priv->debugfs_dir,
+ edac_dev, &inject_ce_fops);
+}
+#endif
+
+static int edac_probe(struct platform_device *pdev)
+{
+ struct edac_device_ctl_info *dci;
+ struct edac_priv *priv;
+ void __iomem *baseaddr;
+ struct resource *res;
+ int irq, ret;
+
+ baseaddr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(baseaddr))
+ return PTR_ERR(baseaddr);
+
+ if (!get_eccstate(baseaddr)) {
+ edac_printk(KERN_INFO, EDAC_DEVICE, "ECC not enabled\n");
+ return -ENXIO;
+ }
+
+ dci = edac_device_alloc_ctl_info(sizeof(*priv), ZYNQMP_OCM_EDAC_STRING,
+ 1, ZYNQMP_OCM_EDAC_STRING, 1, 0, NULL, 0,
+ edac_device_alloc_index());
+ if (!dci)
+ return -ENOMEM;
+
+ priv = dci->pvt_info;
+ platform_set_drvdata(pdev, dci);
+ dci->dev = &pdev->dev;
+ priv->baseaddr = baseaddr;
+ dci->mod_name = pdev->dev.driver->name;
+ dci->ctl_name = ZYNQMP_OCM_EDAC_STRING;
+ dci->dev_name = dev_name(&pdev->dev);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ ret = irq;
+ goto free_dev_ctl;
+ }
+
+ ret = devm_request_irq(&pdev->dev, irq, intr_handler, 0,
+ dev_name(&pdev->dev), dci);
+ if (ret) {
+ edac_printk(KERN_ERR, EDAC_DEVICE, "Failed to request Irq\n");
+ goto free_dev_ctl;
+ }
+
+ /* Enable UE, CE interrupts */
+ writel((OCM_CEINTR_MASK | OCM_UEINTR_MASK), priv->baseaddr + OCM_IEN_OFST);
+
+#ifdef CONFIG_EDAC_DEBUG
+ setup_debugfs(dci);
+#endif
+
+ ret = edac_device_add_device(dci);
+ if (ret)
+ goto free_dev_ctl;
+
+ return 0;
+
+free_dev_ctl:
+ edac_device_free_ctl_info(dci);
+
+ return ret;
+}
+
+static int edac_remove(struct platform_device *pdev)
+{
+ struct edac_device_ctl_info *dci = platform_get_drvdata(pdev);
+ struct edac_priv *priv = dci->pvt_info;
+
+ /* Disable UE, CE interrupts */
+ writel((OCM_CEINTR_MASK | OCM_UEINTR_MASK), priv->baseaddr + OCM_IDS_OFST);
+
+#ifdef CONFIG_EDAC_DEBUG
+ debugfs_remove_recursive(priv->debugfs_dir);
+#endif
+
+ edac_device_del_device(&pdev->dev);
+ edac_device_free_ctl_info(dci);
+
+ return 0;
+}
+
+static const struct of_device_id zynqmp_ocm_edac_match[] = {
+ { .compatible = "xlnx,zynqmp-ocmc-1.0"},
+ { /* end of table */ }
+};
+
+MODULE_DEVICE_TABLE(of, zynqmp_ocm_edac_match);
+
+static struct platform_driver zynqmp_ocm_edac_driver = {
+ .driver = {
+ .name = "zynqmp-ocm-edac",
+ .of_match_table = zynqmp_ocm_edac_match,
+ },
+ .probe = edac_probe,
+ .remove = edac_remove,
+};
+
+module_platform_driver(zynqmp_ocm_edac_driver);
+
+MODULE_AUTHOR("Advanced Micro Devices, Inc");
+MODULE_DESCRIPTION("Xilinx ZynqMP OCM ECC driver");
+MODULE_LICENSE("GPL");
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