[PATCH v7 1/1] EDAC, mellanox: Add ECC support for BlueField DDR4
From: Shravan Kumar Ramani
Date: Tue Jun 25 2019 - 15:14:15 EST
Add ECC support for Mellanox BlueField SoC DDR controller.
This requires SMC to the running Arm Trusted Firmware to report
what is the current memory configuration.
Reviewed-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Shravan Kumar Ramani <sramani@xxxxxxxxxxxx>
---
MAINTAINERS | 5 +
drivers/edac/Kconfig | 7 +
drivers/edac/Makefile | 1 +
drivers/edac/bluefield_edac.c | 356 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 369 insertions(+)
create mode 100644 drivers/edac/bluefield_edac.c
diff --git a/MAINTAINERS b/MAINTAINERS
index d0ed735..a821587 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5669,6 +5669,11 @@ S: Supported
F: drivers/edac/aspeed_edac.c
F: Documentation/devicetree/bindings/edac/aspeed-sdram-edac.txt
+EDAC-BLUEFIELD
+M: Shravan Kumar Ramani <sramani@xxxxxxxxxxxx>
+S: Supported
+F: drivers/edac/bluefield_edac.c
+
EDAC-CALXEDA
M: Robert Richter <rric@xxxxxxxxxx>
L: linux-edac@xxxxxxxxxxxxxxx
diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 5e2e034..43df551 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -504,4 +504,11 @@ config EDAC_ASPEED
First, ECC must be configured in the bootloader. Then, this driver
will expose error counters via the EDAC kernel framework.
+config EDAC_BLUEFIELD
+ tristate "Mellanox BlueField Memory ECC"
+ depends on ARM64 && ((MELLANOX_PLATFORM && ACPI) || COMPILE_TEST)
+ help
+ Support for error detection and correction on the
+ Mellanox BlueField SoCs.
+
endif # EDAC
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index 89ad4a84..0294a67 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -84,3 +84,4 @@ obj-$(CONFIG_EDAC_XGENE) += xgene_edac.o
obj-$(CONFIG_EDAC_TI) += ti_edac.o
obj-$(CONFIG_EDAC_QCOM) += qcom_edac.o
obj-$(CONFIG_EDAC_ASPEED) += aspeed_edac.o
+obj-$(CONFIG_EDAC_BLUEFIELD) += bluefield_edac.o
diff --git a/drivers/edac/bluefield_edac.c b/drivers/edac/bluefield_edac.c
new file mode 100644
index 0000000..e4736eb
--- /dev/null
+++ b/drivers/edac/bluefield_edac.c
@@ -0,0 +1,356 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Bluefield-specific EDAC driver.
+ *
+ * Copyright (c) 2019 Mellanox Technologies.
+ */
+
+#include <linux/acpi.h>
+#include <linux/arm-smccc.h>
+#include <linux/bitfield.h>
+#include <linux/edac.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "edac_module.h"
+
+#define DRIVER_NAME "bluefield-edac"
+
+/*
+ * Mellanox BlueField EMI (External Memory Interface) register definitions.
+ */
+
+#define MLXBF_ECC_CNT 0x340
+#define MLXBF_ECC_CNT__SERR_CNT GENMASK(15, 0)
+#define MLXBF_ECC_CNT__DERR_CNT GENMASK(31, 16)
+
+#define MLXBF_ECC_ERR 0x348
+#define MLXBF_ECC_ERR__SECC BIT(0)
+#define MLXBF_ECC_ERR__DECC BIT(16)
+
+#define MLXBF_ECC_LATCH_SEL 0x354
+#define MLXBF_ECC_LATCH_SEL__START BIT(24)
+
+#define MLXBF_ERR_ADDR_0 0x358
+
+#define MLXBF_ERR_ADDR_1 0x37c
+
+#define MLXBF_SYNDROM 0x35c
+#define MLXBF_SYNDROM__DERR BIT(0)
+#define MLXBF_SYNDROM__SERR BIT(1)
+#define MLXBF_SYNDROM__SYN GENMASK(25, 16)
+
+#define MLXBF_ADD_INFO 0x364
+#define MLXBF_ADD_INFO__ERR_PRANK GENMASK(9, 8)
+
+#define MLXBF_EDAC_MAX_DIMM_PER_MC 2
+#define MLXBF_EDAC_ERROR_GRAIN 8
+
+/*
+ * Request MLNX_SIP_GET_DIMM_INFO
+ *
+ * Retrieve information about DIMM on a certain slot.
+ *
+ * Call register usage:
+ * a0: MLNX_SIP_GET_DIMM_INFO
+ * a1: (Memory controller index) << 16 | (Dimm index in memory controller)
+ * a2-7: not used.
+ *
+ * Return status:
+ * a0: MLXBF_DIMM_INFO defined below describing the DIMM.
+ * a1-3: not used.
+ */
+#define MLNX_SIP_GET_DIMM_INFO 0x82000008
+
+/* Format for the SMC response about the memory information */
+#define MLXBF_DIMM_INFO__SIZE_GB GENMASK_ULL(15, 0)
+#define MLXBF_DIMM_INFO__IS_RDIMM BIT(16)
+#define MLXBF_DIMM_INFO__IS_LRDIMM BIT(17)
+#define MLXBF_DIMM_INFO__IS_NVDIMM BIT(18)
+#define MLXBF_DIMM_INFO__RANKS GENMASK_ULL(23, 21)
+#define MLXBF_DIMM_INFO__PACKAGE_X GENMASK_ULL(31, 24)
+
+struct bluefield_edac_priv {
+ int dimm_ranks[MLXBF_EDAC_MAX_DIMM_PER_MC];
+ void __iomem *emi_base;
+ int dimm_per_mc;
+};
+
+static u64 smc_call1(u64 smc_op, u64 smc_arg)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_smc(smc_op, smc_arg, 0, 0, 0, 0, 0, 0, &res);
+
+ return res.a0;
+}
+
+/*
+ * Gather the ECC information from the External Memory Interface registers
+ * and report it to the edac handler.
+ */
+static void bluefield_gather_report_ecc(struct mem_ctl_info *mci,
+ int error_cnt,
+ int is_single_ecc)
+{
+ struct bluefield_edac_priv *priv = mci->pvt_info;
+ u32 dram_additional_info, err_prank, edea0, edea1;
+ u32 ecc_latch_select, dram_syndrom, serr, derr, syndrom;
+ enum hw_event_mc_err_type ecc_type;
+ u64 ecc_dimm_addr;
+ int ecc_dimm;
+
+ ecc_type = is_single_ecc ? HW_EVENT_ERR_CORRECTED :
+ HW_EVENT_ERR_UNCORRECTED;
+
+ /*
+ * Tell the External Memory Interface to populate the relevant
+ * registers with information about the last ECC error occurrence.
+ */
+ ecc_latch_select = MLXBF_ECC_LATCH_SEL__START;
+ writel(ecc_latch_select, priv->emi_base + MLXBF_ECC_LATCH_SEL);
+
+ /*
+ * Verify that the ECC reported info in the registers is of the
+ * same type as the one asked to report. If not, just report the
+ * error without the detailed information.
+ */
+ dram_syndrom = readl(priv->emi_base + MLXBF_SYNDROM);
+ serr = FIELD_GET(MLXBF_SYNDROM__SERR, dram_syndrom);
+ derr = FIELD_GET(MLXBF_SYNDROM__DERR, dram_syndrom);
+ syndrom = FIELD_GET(MLXBF_SYNDROM__SYN, dram_syndrom);
+
+ if ((is_single_ecc && !serr) || (!is_single_ecc && !derr)) {
+ edac_mc_handle_error(ecc_type, mci, error_cnt, 0, 0, 0,
+ 0, 0, -1, mci->ctl_name, "");
+ return;
+ }
+
+ dram_additional_info = readl(priv->emi_base + MLXBF_ADD_INFO);
+ err_prank = FIELD_GET(MLXBF_ADD_INFO__ERR_PRANK, dram_additional_info);
+
+ ecc_dimm = (err_prank >= 2 && priv->dimm_ranks[0] <= 2) ? 1 : 0;
+
+ edea0 = readl(priv->emi_base + MLXBF_ERR_ADDR_0);
+ edea1 = readl(priv->emi_base + MLXBF_ERR_ADDR_1);
+
+ ecc_dimm_addr = ((u64)edea1 << 32) | edea0;
+
+ edac_mc_handle_error(ecc_type, mci, error_cnt,
+ PFN_DOWN(ecc_dimm_addr),
+ offset_in_page(ecc_dimm_addr),
+ syndrom, ecc_dimm, 0, 0, mci->ctl_name, "");
+}
+
+static void bluefield_edac_check(struct mem_ctl_info *mci)
+{
+ struct bluefield_edac_priv *priv = mci->pvt_info;
+ u32 ecc_count, single_error_count, double_error_count, ecc_error = 0;
+
+ /*
+ * The memory controller might not be initialized by the firmware
+ * when there isn't memory, which may lead to bad register readings.
+ */
+ if (mci->edac_cap == EDAC_FLAG_NONE)
+ return;
+
+ ecc_count = readl(priv->emi_base + MLXBF_ECC_CNT);
+ single_error_count = FIELD_GET(MLXBF_ECC_CNT__SERR_CNT, ecc_count);
+ double_error_count = FIELD_GET(MLXBF_ECC_CNT__DERR_CNT, ecc_count);
+
+ if (single_error_count) {
+ ecc_error |= MLXBF_ECC_ERR__SECC;
+
+ bluefield_gather_report_ecc(mci, single_error_count, 1);
+ }
+
+ if (double_error_count) {
+ ecc_error |= MLXBF_ECC_ERR__DECC;
+
+ bluefield_gather_report_ecc(mci, double_error_count, 0);
+ }
+
+ /* Write to clear reported errors. */
+ if (ecc_count)
+ writel(ecc_error, priv->emi_base + MLXBF_ECC_ERR);
+}
+
+/* Initialize the DIMMs information for the given memory controller. */
+static void bluefield_edac_init_dimms(struct mem_ctl_info *mci)
+{
+ struct bluefield_edac_priv *priv = mci->pvt_info;
+ int mem_ctrl_idx = mci->mc_idx;
+ struct dimm_info *dimm;
+ u64 smc_info, smc_arg;
+ int is_empty = 1, i;
+
+ for (i = 0; i < priv->dimm_per_mc; i++) {
+ dimm = mci->dimms[i];
+
+ smc_arg = mem_ctrl_idx << 16 | i;
+ smc_info = smc_call1(MLNX_SIP_GET_DIMM_INFO, smc_arg);
+
+ if (!FIELD_GET(MLXBF_DIMM_INFO__SIZE_GB, smc_info)) {
+ dimm->mtype = MEM_EMPTY;
+ continue;
+ }
+
+ is_empty = 0;
+
+ dimm->edac_mode = EDAC_SECDED;
+
+ if (FIELD_GET(MLXBF_DIMM_INFO__IS_NVDIMM, smc_info))
+ dimm->mtype = MEM_NVDIMM;
+ else if (FIELD_GET(MLXBF_DIMM_INFO__IS_LRDIMM, smc_info))
+ dimm->mtype = MEM_LRDDR4;
+ else if (FIELD_GET(MLXBF_DIMM_INFO__IS_RDIMM, smc_info))
+ dimm->mtype = MEM_RDDR4;
+ else
+ dimm->mtype = MEM_DDR4;
+
+ dimm->nr_pages =
+ FIELD_GET(MLXBF_DIMM_INFO__SIZE_GB, smc_info) *
+ (SZ_1G / PAGE_SIZE);
+ dimm->grain = MLXBF_EDAC_ERROR_GRAIN;
+
+ /* Mem controller for BlueField only supports x4, x8 and x16 */
+ switch (FIELD_GET(MLXBF_DIMM_INFO__PACKAGE_X, smc_info)) {
+ case 4:
+ dimm->dtype = DEV_X4;
+ break;
+ case 8:
+ dimm->dtype = DEV_X8;
+ break;
+ case 16:
+ dimm->dtype = DEV_X16;
+ break;
+ default:
+ dimm->dtype = DEV_UNKNOWN;
+ }
+
+ priv->dimm_ranks[i] =
+ FIELD_GET(MLXBF_DIMM_INFO__RANKS, smc_info);
+ }
+
+ if (is_empty)
+ mci->edac_cap = EDAC_FLAG_NONE;
+ else
+ mci->edac_cap = EDAC_FLAG_SECDED;
+}
+
+static int bluefield_edac_mc_probe(struct platform_device *pdev)
+{
+ struct bluefield_edac_priv *priv;
+ struct device *dev = &pdev->dev;
+ struct edac_mc_layer layers[1];
+ struct mem_ctl_info *mci;
+ struct resource *emi_res;
+ unsigned int mc_idx, dimm_count;
+ int rc, ret;
+
+ /* Read the MSS (Memory SubSystem) index from ACPI table. */
+ if (device_property_read_u32(dev, "mss_number", &mc_idx)) {
+ dev_warn(dev, "bf_edac: MSS number unknown\n");
+ return -EINVAL;
+ }
+
+ /* Read the DIMMs per MC from ACPI table. */
+ if (device_property_read_u32(dev, "dimm_per_mc", &dimm_count)) {
+ dev_warn(dev, "bf_edac: DIMMs per MC unknown\n");
+ return -EINVAL;
+ }
+
+ if (dimm_count > MLXBF_EDAC_MAX_DIMM_PER_MC) {
+ dev_warn(dev, "bf_edac: DIMMs per MC not valid\n");
+ return -EINVAL;
+ }
+
+ emi_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!emi_res)
+ return -EINVAL;
+
+ layers[0].type = EDAC_MC_LAYER_SLOT;
+ layers[0].size = dimm_count;
+ layers[0].is_virt_csrow = true;
+
+ mci = edac_mc_alloc(mc_idx, ARRAY_SIZE(layers), layers, sizeof(*priv));
+ if (!mci)
+ return -ENOMEM;
+
+ priv = mci->pvt_info;
+
+ priv->dimm_per_mc = dimm_count;
+ priv->emi_base = devm_ioremap_resource(dev, emi_res);
+ if (IS_ERR(priv->emi_base)) {
+ dev_err(dev, "failed to map EMI IO resource\n");
+ ret = PTR_ERR(priv->emi_base);
+ goto err;
+ }
+
+ mci->pdev = dev;
+ mci->mtype_cap = MEM_FLAG_DDR4 | MEM_FLAG_RDDR4 |
+ MEM_FLAG_LRDDR4 | MEM_FLAG_NVDIMM;
+ mci->edac_ctl_cap = EDAC_FLAG_SECDED;
+
+ mci->mod_name = DRIVER_NAME;
+ mci->ctl_name = "BlueField_Memory_Controller";
+ mci->dev_name = dev_name(dev);
+ mci->edac_check = bluefield_edac_check;
+
+ /* Initialize mci with the actual populated DIMM information. */
+ bluefield_edac_init_dimms(mci);
+
+ platform_set_drvdata(pdev, mci);
+
+ /* Register with EDAC core */
+ rc = edac_mc_add_mc(mci);
+ if (rc) {
+ dev_err(dev, "failed to register with EDAC core\n");
+ ret = rc;
+ goto err;
+ }
+
+ /* Only POLL mode supported so far. */
+ edac_op_state = EDAC_OPSTATE_POLL;
+
+ return 0;
+
+err:
+ edac_mc_free(mci);
+
+ return ret;
+
+}
+
+static int bluefield_edac_mc_remove(struct platform_device *pdev)
+{
+ struct mem_ctl_info *mci = platform_get_drvdata(pdev);
+
+ edac_mc_del_mc(&pdev->dev);
+ edac_mc_free(mci);
+
+ return 0;
+}
+
+static const struct acpi_device_id bluefield_mc_acpi_ids[] = {
+ {"MLNXBF08", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(acpi, bluefield_mc_acpi_ids);
+
+static struct platform_driver bluefield_edac_mc_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .acpi_match_table = bluefield_mc_acpi_ids,
+ },
+ .probe = bluefield_edac_mc_probe,
+ .remove = bluefield_edac_mc_remove,
+};
+
+module_platform_driver(bluefield_edac_mc_driver);
+
+MODULE_DESCRIPTION("Mellanox BlueField memory edac driver");
+MODULE_AUTHOR("Mellanox Technologies");
+MODULE_LICENSE("GPL v2");
--
2.1.2