Re: [PATCH 2/2] edac: sifive: Add EDAC driver for SiFive FU540-C000 chip

From: Paul Walmsley
Date: Sun Mar 24 2019 - 20:23:32 EST


Hi Yash,

Just a few brief comments here:

On Wed, 20 Mar 2019, Yash Shah wrote:

> This EDAC driver supports:
> - Initial configuration reporting on bootup via debug logs
> - ECC event monitoring and reporting through the EDAC framework
> - ECC event injection
>

It's probably worth mentioning here, as you did in the subject line, that
this is for the FU540-C000 platform.

> This driver is partially based on pnd2_edac.c and altera_edac.c
>
> Initially L2 Cache controller is added as a subcomponent to
> this EDAC driver.
>
> Signed-off-by: Yash Shah <yash.shah@xxxxxxxxxx>
> ---
> arch/riscv/Kconfig | 1 +
> drivers/edac/Kconfig | 13 ++
> drivers/edac/Makefile | 1 +
> drivers/edac/sifive_edac.c | 297 +++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 312 insertions(+)
> create mode 100644 drivers/edac/sifive_edac.c
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 515fc3c..fede4b6 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -49,6 +49,7 @@ config RISCV
> select RISCV_TIMER
> select GENERIC_IRQ_MULTI_HANDLER
> select ARCH_HAS_PTE_SPECIAL
> + select EDAC_SUPPORT
>
> config MMU
> def_bool y

This part of the patch either needs to get an ack from Palmer, or should
be split into a final, separate patch that Palmer can merge separately.
That way it will avoid unexpected merge conflicts if anything that Palmer
merges changes this file.

> diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
> index e286b5b..112d9d1 100644
> --- a/drivers/edac/Kconfig
> +++ b/drivers/edac/Kconfig
> @@ -440,6 +440,19 @@ config EDAC_ALTERA_SDMMC
> Support for error detection and correction on the
> Altera SDMMC FIFO Memory for Altera SoCs.
>
> +config EDAC_SIFIVE
> + tristate "Sifive ECC"
> + depends on RISCV
> + help
> + Support for error detection and correction on the SiFive SoCs.
> +
> +config EDAC_SIFIVE_L2
> + bool "SiFive L2 Cache ECC"
> + depends on EDAC_SIFIVE=y
> + help
> + Support for error detection and correction of the L2 cache
> + memory on SiFive SoCs.
> +
> config EDAC_SYNOPSYS
> tristate "Synopsys DDR Memory Controller"
> depends on ARCH_ZYNQ || ARCH_ZYNQMP
> diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
> index 716096d..b16dce8 100644
> --- a/drivers/edac/Makefile
> +++ b/drivers/edac/Makefile
> @@ -74,6 +74,7 @@ obj-$(CONFIG_EDAC_OCTEON_PCI) += octeon_edac-pci.o
> obj-$(CONFIG_EDAC_THUNDERX) += thunderx_edac.o
>
> obj-$(CONFIG_EDAC_ALTERA) += altera_edac.o
> +obj-$(CONFIG_EDAC_SIFIVE) += sifive_edac.o
> obj-$(CONFIG_EDAC_SYNOPSYS) += synopsys_edac.o
> obj-$(CONFIG_EDAC_XGENE) += xgene_edac.o
> obj-$(CONFIG_EDAC_TI) += ti_edac.o
> diff --git a/drivers/edac/sifive_edac.c b/drivers/edac/sifive_edac.c
> new file mode 100644
> index 0000000..e11ae6b5
> --- /dev/null
> +++ b/drivers/edac/sifive_edac.c
> @@ -0,0 +1,297 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * SiFive EDAC Driver
> + *
> + * Copyright (C) 2018-2019 SiFive, Inc.
> + *
> + */
> +#include <linux/edac.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include "edac_module.h"
> +
> +#define SIFIVE_EDAC_DIRFIX_LOW 0x100
> +#define SIFIVE_EDAC_DIRFIX_HIGH 0x104
> +#define SIFIVE_EDAC_DIRFIX_COUNT 0x108
> +
> +#define SIFIVE_EDAC_DATFIX_LOW 0x140
> +#define SIFIVE_EDAC_DATFIX_HIGH 0x144
> +#define SIFIVE_EDAC_DATFIX_COUNT 0x148
> +
> +#define SIFIVE_EDAC_DATFAIL_LOW 0x160
> +#define SIFIVE_EDAC_DATFAIL_HIGH 0x164
> +#define SIFIVE_EDAC_DATFAIL_COUNT 0x168
> +
> +#define SIFIVE_EDAC_ECCINJECTERR 0x40
> +#define SIFIVE_EDAC_CONFIG 0x00
> +
> +#define SIFIVE_EDAC_MAX_INTR 3
> +
> +/************************* EDAC Parent Probe *************************/
> +
> +static const struct of_device_id sifive_edac_device_of_match[];
> +
> +static const struct of_device_id sifive_edac_of_match[] = {
> + { .compatible = "sifive,ecc-manager" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, sifive_edac_of_match);
> +
> +static int sifive_edac_probe(struct platform_device *pdev)
> +{
> + of_platform_populate(pdev->dev.of_node, sifive_edac_device_of_match,
> + NULL, &pdev->dev);
> + return 0;
> +}
> +
> +static struct platform_driver sifive_edac_driver = {
> + .probe = sifive_edac_probe,
> + .driver = {
> + .name = "ecc_manager",

As mentioned before we don't have an ECC manager IP block, so we probably
should figure out a different approach here, if possible.

> + .of_match_table = sifive_edac_of_match,
> + },
> +};
> +module_platform_driver(sifive_edac_driver);
> +
> +struct sifive_edac_device_prv {
> + void (*setup)(struct edac_device_ctl_info *dci);
> + irqreturn_t (*ecc_irq_handler)(int irq, void *dev_id);
> + const struct file_operations *inject_fops;
> +};
> +
> +struct sifive_edac_device_dev {
> + void __iomem *base;
> + int irq[SIFIVE_EDAC_MAX_INTR];
> + struct sifive_edac_device_prv *data;
> + char *edac_dev_name;
> +};
> +
> +enum {
> + dir_corr = 0,
> + data_corr,
> + data_uncorr,
> +};

Best to put these in all caps, per coding-style.rst:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst#n727

> +
> +static struct dentry *sifive_edac_test;
> +
> +static ssize_t sifive_edac_l2_write(struct file *file, const char __user *data,
> + size_t count, loff_t *ppos)
> +{
> + struct edac_device_ctl_info *dci = file->private_data;
> + struct sifive_edac_device_dev *drvdata = dci->pvt_info;
> + unsigned int val;
> +
> + if (kstrtouint_from_user(data, count, 0, &val))
> + return -EINVAL;
> + if ((val >= 0 && val < 0xFF) || (val >= 0x10000 && val < 0x100FF))
> + writel(val, drvdata->base + SIFIVE_EDAC_ECCINJECTERR);
> + else
> + return -EINVAL;
> + return count;
> +}
> +
> +static const struct file_operations sifive_edac_l2_fops = {
> + .owner = THIS_MODULE,
> + .open = simple_open,
> + .write = sifive_edac_l2_write
> +};
> +
> +static void setup_sifive_debug(struct edac_device_ctl_info *edac_dci,
> + const struct sifive_edac_device_prv *prv)
> +{
> + struct sifive_edac_device_dev *drvdata = edac_dci->pvt_info;
> +
> + if (!IS_ENABLED(CONFIG_EDAC_DEBUG))
> + return;

Can all of these debugfs functions be wrapped with an #if ... #endif such
that, if CONFIG_EDAC_DEBUG is not set, they will all be stripped out by
the preprocessor?

> +
> + sifive_edac_test = edac_debugfs_create_dir(drvdata->edac_dev_name);
> + if (!sifive_edac_test)
> + return;
> +
> + if (!edac_debugfs_create_file("sifive_debug_inject_error", 0200,
> + sifive_edac_test, edac_dci,
> + prv->inject_fops))
> + debugfs_remove_recursive(sifive_edac_test);
> +}
> +
> +static void teardown_sifive_debug(void)
> +{
> + debugfs_remove_recursive(sifive_edac_test);
> +}
> +
> +/*
> + * sifive_edac_l2_int_handler - ISR function for l2 cache controller
> + * @irq: Irq Number
> + * @device: Pointer to the edac device controller instance
> + *
> + * This routine is triggered whenever there is ECC error detected
> + *
> + * Return: Always returns IRQ_HANDLED
> + */
> +static irqreturn_t sifive_edac_l2_int_handler(int irq, void *device)
> +{
> + struct edac_device_ctl_info *dci =
> + (struct edac_device_ctl_info *)device;
> + struct sifive_edac_device_dev *drvdata = dci->pvt_info;
> + u32 regval, add_h, add_l;
> +
> + if (irq == drvdata->irq[dir_corr]) {
> + add_h = readl(drvdata->base + SIFIVE_EDAC_DIRFIX_HIGH);
> + add_l = readl(drvdata->base + SIFIVE_EDAC_DIRFIX_LOW);
> + dev_err(dci->dev,
> + "DirError at address 0x%08X.%08X\n", add_h, add_l);
> + regval = readl(drvdata->base + SIFIVE_EDAC_DIRFIX_COUNT);
> + edac_device_handle_ce(dci, 0, 0, "DirECCFix");
> + }
> + if (irq == drvdata->irq[data_corr]) {
> + add_h = readl(drvdata->base + SIFIVE_EDAC_DATFIX_HIGH);
> + add_l = readl(drvdata->base + SIFIVE_EDAC_DATFIX_LOW);
> + dev_err(dci->dev,
> + "DataError at address 0x%08X.%08X\n", add_h, add_l);
> + regval = readl(drvdata->base + SIFIVE_EDAC_DATFIX_COUNT);
> + edac_device_handle_ce(dci, 0, 0, "DatECCFix");
> + }
> + if (irq == drvdata->irq[data_uncorr]) {
> + add_h = readl(drvdata->base + SIFIVE_EDAC_DATFAIL_HIGH);
> + add_l = readl(drvdata->base + SIFIVE_EDAC_DATFAIL_LOW);
> + dev_err(dci->dev,
> + "DataFail at address 0x%08X.%08X\n", add_h, add_l);
> + regval = readl(drvdata->base + SIFIVE_EDAC_DATFAIL_COUNT);
> + edac_device_handle_ue(dci, 0, 0, "DatECCFail");
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void sifive_edac_l2_config_read(struct edac_device_ctl_info *dci)
> +{
> + struct sifive_edac_device_dev *drvdata = dci->pvt_info;
> + u32 regval, val;
> +
> + regval = readl(drvdata->base + SIFIVE_EDAC_CONFIG);
> + val = regval & 0xFF;
> + dev_info(dci->dev, "No. of Banks in the cache: %d\n", val);
> + val = (regval & 0xFF00) >> 8;
> + dev_info(dci->dev, "No. of ways per bank: %d\n", val);
> + val = (regval & 0xFF0000) >> 16;
> + dev_info(dci->dev, "Sets per bank: %llu\n", (uint64_t)1 << val);
> + val = (regval & 0xFF000000) >> 24;
> + dev_info(dci->dev,
> + "Bytes per cache block: %llu\n", (uint64_t)1 << val);
> +}
> +
> +static const struct sifive_edac_device_prv l2ecc_data = {
> + .setup = sifive_edac_l2_config_read,
> + .inject_fops = &sifive_edac_l2_fops,
> + .ecc_irq_handler = sifive_edac_l2_int_handler,
> +};
> +
> +/*
> + * sifive_edac_device_probe()
> + * This is a generic EDAC device driver that will support
> + * various SiFive memory devices as well as the memories
> + * for other peripherals. Module specific initialization is
> + * done by passing the function index in the device tree.
> + */
> +static int sifive_edac_device_probe(struct platform_device *pdev)
> +{
> + struct edac_device_ctl_info *dci;
> + struct sifive_edac_device_dev *drvdata;
> + int rc, i;
> + struct resource *res;
> + void __iomem *baseaddr;
> + struct device_node *np = pdev->dev.of_node;
> + char *ecc_name = (char *)np->name;
> + static int dev_instance;
> +
> + /* Get the data from the platform device */
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + baseaddr = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(baseaddr))
> + return PTR_ERR(baseaddr);
> +
> + dci = edac_device_alloc_ctl_info(sizeof(*drvdata), ecc_name,
> + 1, ecc_name, 1, 1, NULL, 0,
> + dev_instance++);
> + if (IS_ERR(dci))
> + return PTR_ERR(dci);
> +
> + drvdata = dci->pvt_info;
> + drvdata->base = baseaddr;
> + drvdata->edac_dev_name = ecc_name;
> + dci->dev = &pdev->dev;
> + dci->mod_name = "Sifive ECC Manager";
> + dci->ctl_name = dev_name(&pdev->dev);
> + dci->dev_name = dev_name(&pdev->dev);
> +
> + /* Get driver specific data for this EDAC device */
> + drvdata->data = of_match_node(sifive_edac_device_of_match, np)->data;
> +
> + setup_sifive_debug(dci, drvdata->data);
> +
> + if (drvdata->data->setup)
> + drvdata->data->setup(dci);
> +
> + for (i = 0; i < SIFIVE_EDAC_MAX_INTR; i++) {
> + drvdata->irq[i] = platform_get_irq(pdev, i);
> + rc = devm_request_irq(&pdev->dev, drvdata->irq[i],
> + sifive_edac_l2_int_handler, 0,
> + dev_name(&pdev->dev), (void *)dci);
> + if (rc) {
> + dev_err(&pdev->dev,
> + "Could not request IRQ %d\n", drvdata->irq[i]);
> + goto del_edac_device;
> + }
> + }
> +
> + rc = edac_device_add_device(dci);
> + if (rc) {
> + dev_err(&pdev->dev, "failed to register with EDAC core\n");
> + goto del_edac_device;
> + }
> +
> + return rc;
> +
> +del_edac_device:
> + teardown_sifive_debug();
> + edac_device_del_device(&pdev->dev);
> + edac_device_free_ctl_info(dci);
> +
> + return rc;
> +}
> +
> +static int sifive_edac_device_remove(struct platform_device *pdev)
> +{
> + struct edac_device_ctl_info *dci = platform_get_drvdata(pdev);
> +
> + teardown_sifive_debug();
> + edac_device_del_device(&pdev->dev);
> + edac_device_free_ctl_info(dci);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id sifive_edac_device_of_match[] = {
> + { .compatible = "sifive,ccache0", .data = &l2ecc_data },

This match string should be "sifive,fu540-c000-ccache" if
the intention is to probe against the L2 controller.

> + { /* end of table */ },
> +};
> +MODULE_DEVICE_TABLE(of, sifive_edac_device_of_match);
> +
> +static struct platform_driver sifive_edac_device_driver = {
> + .driver = {
> + .name = "sifive_edac_device",
> + .owner = THIS_MODULE,
> + .of_match_table = sifive_edac_device_of_match,
> + },
> + .probe = sifive_edac_device_probe,
> + .remove = sifive_edac_device_remove,
> +};
> +
> +module_platform_driver(sifive_edac_device_driver);
> +
> +MODULE_AUTHOR("SiFive Inc.");
> +MODULE_DESCRIPTION("SiFive EDAC driver");
> +MODULE_LICENSE("GPL v2");

- Paul