From: Rui Zhao <ruiz...@microsoft.com>
New driver supports DRAM error detection and correction on DMC520
controller.
Validated on actual hardware: DRAM errors showed up once the DDR core
voltage was lowered down by 200+mV using test tool.
Signed-off-by: Rui Zhao <ruiz...@microsoft.com>
[sl: minor nits in commit message and code, added maintainers entry]
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
MAINTAINERS | 6 +
drivers/edac/Kconfig | 7 +
drivers/edac/Makefile | 1 +
drivers/edac/dmc520_edac.c | 495 +++++++++++++++++++++++++++++++++++++
4 files changed, 509 insertions(+)
create mode 100644 drivers/edac/dmc520_edac.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 32d444476a90..e8ec396a1475 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5429,6 +5429,12 @@ F: Documentation/driver-api/edac.rst
F: drivers/edac/
F: include/linux/edac.h
+EDAC-DMC520
+M: Rui Zhao <ruiz...@microsoft.com>
+L: linux-e...@vger.kernel.org
+S: Supported
+F: drivers/edac/dmc520_edac.c
+
EDAC-E752X
M: Mark Gross <mark.gr...@intel.com>
L: linux-e...@vger.kernel.org
diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index e286b5b99003..78ffdb9cfa6b 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -475,4 +475,11 @@ config EDAC_QCOM
For debugging issues having to do with stability and overall system
health, you should probably say 'Y' here.
+config EDAC_DMC520
+ tristate "ARM DMC-520 ECC"
+ depends on ARM64
+ help
+ Support for error detection and correction on
+ SoCs with the ARM DMC-520 DRAM controller.
+
endif # EDAC
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index 716096d08ea0..793d64f525d4 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -78,3 +78,4 @@ obj-$(CONFIG_EDAC_SYNOPSYS) += synopsys_edac.o
obj-$(CONFIG_EDAC_XGENE) += xgene_edac.o
obj-$(CONFIG_EDAC_TI) += ti_edac.o
obj-$(CONFIG_EDAC_QCOM) += qcom_edac.o
+obj-$(CONFIG_EDAC_DMC520) += dmc520_edac.o
diff --git a/drivers/edac/dmc520_edac.c b/drivers/edac/dmc520_edac.c
new file mode 100644
index 000000000000..5f14889074af
--- /dev/null
+++ b/drivers/edac/dmc520_edac.c
@@ -0,0 +1,495 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/edac.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/interrupt.h>
+#include <linux/bitfield.h>
+#include <edac_mc.h>
+
+/* DMC-520 registers */
+#define REG_OFFSET_FEATURE_CONFIG 0x130
+#define REG_OFFSET_ECC_ERRC_COUNT_31_00 0x158
+#define REG_OFFSET_ECC_ERRC_COUNT_63_32 0x15C
+#define REG_OFFSET_ECC_ERRD_COUNT_31_00 0x160
+#define REG_OFFSET_ECC_ERRD_COUNT_63_32 0x164
+#define REG_OFFSET_FEATURE_CONTROL_NEXT 0x1F0
+#define REG_OFFSET_INTERRUPT_CONTROL 0x500
+#define REG_OFFSET_INTERRUPT_CLR 0x508
+#define REG_OFFSET_INTERRUPT_STATUS 0x510
+#define REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_31_00 0x528
+#define REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_63_32 0x52C
+#define REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_31_00 0x530
+#define REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_63_32 0x534
+#define REG_OFFSET_ADDRESS_CONTROL_NOW 0x1010
+#define REG_OFFSET_DECODE_CONTROL_NOW 0x1014
+#define REG_OFFSET_MEMORY_TYPE_NOW 0x1128
+
+/* DMC-520 types, masks and bitfields */
+#define MEMORY_TYPE_LPDDR3 0
+#define MEMORY_TYPE_DDR3 1
+#define MEMORY_TYPE_DDR4 2
+#define MEMORY_TYPE_LPDDR4 3
+
+#define MEMORY_DEV_WIDTH_X4 0
+#define MEMORY_DEV_WIDTH_X8 1
+#define MEMORY_DEV_WIDTH_X16 2
+#define MEMORY_DEV_WIDTH_X32 3
+
+#define DRAM_ECC_INT_CE_MASK BIT(2)
+#define DRAM_ECC_INT_UE_MASK BIT(3)
+#define DRAM_ECC_INT_CE_OVERFLOW_MASK BIT(18)
+#define DRAM_ECC_INT_UE_OVERFLOW_MASK BIT(19)
+
+#define REG_FIELD_DRAM_ECC_ENABLED GENMASK(1, 0)
+#define REG_FIELD_MEMORY_TYPE GENMASK(2, 0)
+#define REG_FIELD_DEVICE_WIDTH GENMASK(9, 8)
+#define REG_FIELD_ADDRESS_CONTROL_COL GENMASK(2, 0)
+#define REG_FIELD_ADDRESS_CONTROL_ROW GENMASK(10, 8)
+#define REG_FIELD_ADDRESS_CONTROL_BANK GENMASK(18, 16)
+#define REG_FIELD_ADDRESS_CONTROL_RANK GENMASK(25, 24)
+#define REG_FIELD_ERR_INFO_LOW_VALID BIT(0)
+#define REG_FIELD_ERR_INFO_LOW_COL GENMASK(10, 1)
+#define REG_FIELD_ERR_INFO_LOW_ROW GENMASK(28, 11)
+#define REG_FIELD_ERR_INFO_LOW_RANK GENMASK(31, 29)
+#define REG_FIELD_ERR_INFO_HIGH_BANK GENMASK(3, 0)
+#define REG_FIELD_ERR_INFO_HIGH_VALID BIT(31)
+
+#define DRAM_ECC_MIN_INT_OVERFLOW_ERROR_COUNT 256
+#define DRAM_ADDRESS_CONTROL_MIN_COL_BITS 8
+#define DRAM_ADDRESS_CONTROL_MIN_ROW_BITS 11
+
+/* Driver settings */
+#define DMC520_EDAC_CHANS 1
+#define DMC520_EDAC_ERR_GRAIN 1
+#define DMC520_EDAC_INT_COUNT 2
+#define DMC520_EDAC_BUS_WIDTH 8
+
+#define EDAC_MSG_BUF_SIZE 128
+#define EDAC_MOD_NAME "dmc520-edac"
+#define EDAC_CTL_NAME "dmc520"
+
+struct ecc_error_info {
+ u32 col;
+ u32 row;
+ u32 bank;
+ u32 rank;
+};
+
+struct dmc520_edac {
+ void __iomem *reg_base;
+ char message[EDAC_MSG_BUF_SIZE];
+};
+
+static int dmc520_mc_idx;
+
+static u32 dmc520_read_reg(struct dmc520_edac *edac, u32 offset)
+{
+ return readl(edac->reg_base + offset);
+}
+
+static void dmc520_write_reg(struct dmc520_edac *edac, u32 val, u32 offset)
+{
+ writel(val, edac->reg_base + offset);
+}
+
+static u32 dmc520_calc_ecc_error(u32 value)
+{
+ u32 total = 0;
+
+ /* Each rank's error counter takes one byte */
+ while (value > 0) {
+ total += (value & 0xFF);
+ value >>= 8;
+ }
+ return total;
+}
+
+static u32 dmc520_get_ecc_error_count(struct dmc520_edac *edac, bool is_ce)
+{
+ u32 reg_offset_low, reg_offset_high;
+ u32 err_low, err_high;
+ u32 ce_count;
+
+ reg_offset_low = is_ce ? REG_OFFSET_ECC_ERRC_COUNT_31_00 :
+ REG_OFFSET_ECC_ERRD_COUNT_31_00;
+ reg_offset_high = is_ce ? REG_OFFSET_ECC_ERRC_COUNT_63_32 :
+ REG_OFFSET_ECC_ERRD_COUNT_63_32;
+
+ err_low = dmc520_read_reg(edac, reg_offset_low);
+ err_high = dmc520_read_reg(edac, reg_offset_high);
+
+ ce_count = dmc520_calc_ecc_error(err_low) +
+ dmc520_calc_ecc_error(err_high);
+
+ /* Reset error counters */
+ dmc520_write_reg(edac, 0, reg_offset_low);
+ dmc520_write_reg(edac, 0, reg_offset_high);
+
+ return ce_count;
+}
+
+static bool dmc520_get_ecc_error_info(struct dmc520_edac *edac,
+ bool is_ce,
+ struct ecc_error_info *info)
+{
+ u32 reg_offset_low, reg_offset_high;
+ u32 reg_val_low, reg_val_high;
+ bool valid;
+
+ reg_offset_low = is_ce ? REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_31_00 :
+ REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_31_00;
+ reg_offset_high = is_ce ? REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_63_32 :
+ REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_63_32;
+
+ reg_val_low = dmc520_read_reg(edac, reg_offset_low);
+ reg_val_high = dmc520_read_reg(edac, reg_offset_high);
+
+ valid = (FIELD_GET(REG_FIELD_ERR_INFO_LOW_VALID, reg_val_low) != 0) &&
+ (FIELD_GET(REG_FIELD_ERR_INFO_HIGH_VALID, reg_val_high) != 0);
+
+ if (info) {
+ if (valid) {
+ info->col = FIELD_GET(REG_FIELD_ERR_INFO_LOW_COL,
+ reg_val_low);
+ info->row = FIELD_GET(REG_FIELD_ERR_INFO_LOW_ROW,
+ reg_val_low);
+ info->rank = FIELD_GET(REG_FIELD_ERR_INFO_LOW_RANK,
+ reg_val_low);
+ info->bank = FIELD_GET(REG_FIELD_ERR_INFO_HIGH_BANK,
+ reg_val_high);
+ } else {
+ memset(info, 0, sizeof(struct ecc_error_info));
+ }
+ }
+
+ return valid;
+}
+
+static bool dmc520_is_ecc_enabled(struct dmc520_edac *edac)
+{
+ u32 reg_val = dmc520_read_reg(edac, REG_OFFSET_FEATURE_CONFIG);
+
+ return (FIELD_GET(REG_FIELD_DRAM_ECC_ENABLED, reg_val) != 0);
+}
+
+static enum mem_type dmc520_get_mtype(struct dmc520_edac *edac)
+{
+ enum mem_type mt;
+ u32 reg_val, type;
+
+ reg_val = dmc520_read_reg(edac, REG_OFFSET_MEMORY_TYPE_NOW);
+ type = FIELD_GET(REG_FIELD_MEMORY_TYPE, reg_val);
+
+ switch (type) {
+ case MEMORY_TYPE_LPDDR3:
+ case MEMORY_TYPE_DDR3:
+ mt = MEM_DDR3;
+ break;
+
+ case MEMORY_TYPE_DDR4:
+ case MEMORY_TYPE_LPDDR4:
+ default:
+ mt = MEM_DDR4;
+ break;
+ }
+ return mt;
+}
+
+static enum dev_type dmc520_get_dtype(struct dmc520_edac *edac)
+{
+ enum dev_type dt;
+ u32 reg_val, device_width;
+
+ reg_val = dmc520_read_reg(edac, REG_OFFSET_MEMORY_TYPE_NOW);
+ device_width = FIELD_GET(REG_FIELD_DEVICE_WIDTH, reg_val);
+
+ switch (device_width) {
+ case MEMORY_DEV_WIDTH_X4:
+ dt = DEV_X4;
+ break;
+
+ case MEMORY_DEV_WIDTH_X8:
+ dt = DEV_X8;
+ break;
+
+ case MEMORY_DEV_WIDTH_X16:
+ dt = DEV_X16;
+ break;
+
+ case MEMORY_DEV_WIDTH_X32:
+ dt = DEV_X32;
+ break;
+ }
+ return dt;
+}
+
+static u32 dmc520_get_rank_count(void __iomem *reg_base)
+{
+ u32 reg_val, rank_bits;
+
+ reg_val = readl(reg_base + REG_OFFSET_ADDRESS_CONTROL_NOW);
+ rank_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_RANK, reg_val);
+
+ return (1 << rank_bits);
+}
+
+static u64 dmc520_get_rank_size(struct dmc520_edac *edac)
+{
+ u32 reg_val, col_bits, row_bits, bank_bits;
+
+ reg_val = dmc520_read_reg(edac, REG_OFFSET_ADDRESS_CONTROL_NOW);
+
+ col_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_COL, reg_val) +
+ DRAM_ADDRESS_CONTROL_MIN_COL_BITS;
+ row_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_ROW, reg_val) +
+ DRAM_ADDRESS_CONTROL_MIN_ROW_BITS;
+ bank_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_BANK, reg_val);
+
+ return (u64)DMC520_EDAC_BUS_WIDTH << (col_bits + row_bits + bank_bits);
+}
+
+static void dmc520_handle_ecc_errors(struct mem_ctl_info *mci,
+ bool is_ce,
+ bool overflow)
+{
+ struct ecc_error_info info;
+ struct dmc520_edac *edac;
+ u32 cnt;
+
+ edac = mci->pvt_info;
+ dmc520_get_ecc_error_info(edac, is_ce, &info);
+
+ cnt = dmc520_get_ecc_error_count(edac, is_ce);
+
+ if (overflow)
+ cnt += DRAM_ECC_MIN_INT_OVERFLOW_ERROR_COUNT;
+
+ if (cnt > 0) {
+ snprintf(edac->message, ARRAY_SIZE(edac->message),
+ "rank:%d bank:%d row:%d col:%d",
+ info.rank, info.bank,
+ info.row, info.col);
+
+ edac_mc_handle_error((is_ce ? HW_EVENT_ERR_CORRECTED :
+ HW_EVENT_ERR_UNCORRECTED),
+ mci, cnt, 0, 0, 0, info.rank, 0, -1,
+ edac->message, "");
+ }
+}
+
+static irqreturn_t dmc520_edac_isr(int irq, void *data, bool is_ce)
+{
+ u32 i_mask, o_mask, status;
+ bool overflow;
+ struct mem_ctl_info *mci;
+ struct dmc520_edac *edac;
+
+ mci = data;
+ edac = mci->pvt_info;
+
+ i_mask = is_ce ? DRAM_ECC_INT_CE_MASK : DRAM_ECC_INT_UE_MASK;
+ o_mask = is_ce ? DRAM_ECC_INT_CE_OVERFLOW_MASK :
+ DRAM_ECC_INT_UE_OVERFLOW_MASK;
+
+ status = dmc520_read_reg(edac, REG_OFFSET_INTERRUPT_STATUS);
+ overflow = ((status & o_mask) != 0);
+
+ dmc520_handle_ecc_errors(mci, is_ce, overflow);
+
+ dmc520_write_reg(edac, i_mask, REG_OFFSET_INTERRUPT_CLR);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t dmc520_edac_ce_isr(int irq, void *data)
+{
+ return dmc520_edac_isr(irq, data, true);
+}
+
+static irqreturn_t dmc520_edac_ue_isr(int irq, void *data)
+{
+ return dmc520_edac_isr(irq, data, false);
+}
+
+static void dmc520_init_csrow(struct mem_ctl_info *mci)
+{
+ struct csrow_info *csi;
+ struct dimm_info *dimm;
+ int row, ch;
+ enum dev_type dt;
+ enum mem_type mt;
+ u64 rs;
+ u32 pages_per_rank;
+ struct dmc520_edac *edac = mci->pvt_info;
+
+ dt = dmc520_get_dtype(edac);
+ mt = dmc520_get_mtype(edac);
+ rs = dmc520_get_rank_size(edac);
+ pages_per_rank = rs >> PAGE_SHIFT;
+
+ for (row = 0; row < mci->nr_csrows; row++) {
+ csi = mci->csrows[row];
+
+ for (ch = 0; ch < csi->nr_channels; ch++) {
+ dimm = csi->channels[ch]->dimm;
+ dimm->edac_mode = EDAC_FLAG_SECDED;
+ dimm->mtype = mt;
+ dimm->nr_pages = pages_per_rank / csi->nr_channels;
+ dimm->grain = DMC520_EDAC_ERR_GRAIN;
+ dimm->dtype = dt;
+ }
+ }
+}
+
+static int dmc520_edac_probe(struct platform_device *pdev)
+{
+ struct dmc520_edac *edac;
+ struct mem_ctl_info *mci;
+ struct edac_mc_layer layers[2];
+ int ret, irq;
+ struct resource *res;
+ void __iomem *reg_base;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ reg_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(reg_base))
+ return PTR_ERR(reg_base);
+
+ layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
+ layers[0].size = dmc520_get_rank_count(reg_base);
+ layers[0].is_virt_csrow = true;
+
+ layers[1].type = EDAC_MC_LAYER_CHANNEL;
+ layers[1].size = DMC520_EDAC_CHANS;
+ layers[1].is_virt_csrow = false;
+
+ mci = edac_mc_alloc(dmc520_mc_idx++, ARRAY_SIZE(layers), layers,
+ sizeof(struct dmc520_edac));
+ if (!mci) {
+ edac_printk(KERN_ERR, EDAC_MOD_NAME,
+ "Failed to allocate memory for mc instance\n");
+ return -ENOMEM;
+ }
+
+ edac = mci->pvt_info;
+ edac->reg_base = reg_base;
+
+ if (!dmc520_is_ecc_enabled(edac)) {
+ edac_printk(KERN_ERR, EDAC_MOD_NAME, "ECC not enabled\n");
+ ret = -ENXIO;
+ goto err;
+ }
+
+ platform_set_drvdata(pdev, mci);
+
+ mci->pdev = &pdev->dev;
+ mci->mtype_cap = MEM_FLAG_DDR3 | MEM_FLAG_DDR4;
+ mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
+ mci->scrub_cap = SCRUB_HW_SRC;
+ mci->scrub_mode = SCRUB_NONE;
+ mci->edac_cap = EDAC_FLAG_SECDED;
+ mci->ctl_name = EDAC_CTL_NAME;
+ mci->dev_name = dev_name(mci->pdev);
+ mci->mod_name = EDAC_MOD_NAME;
+ mci->ctl_page_to_phys = NULL;
+
+ edac_op_state = EDAC_OPSTATE_INT;
+
+ dmc520_init_csrow(mci);
+
+ ret = edac_mc_add_mc(mci);
+ if (ret) {
+ edac_printk(KERN_ERR, EDAC_MOD_NAME,
+ "Failed to register with EDAC core\n");
+ goto err;
+ }
+
+ for (irq = 0; irq < DMC520_EDAC_INT_COUNT; ++irq) {
+ irq_handler_t dmc520_edac_isr;
+ int irq_id = platform_get_irq(pdev, irq);
+
+ if (irq_id < 0) {
+ edac_printk(KERN_ERR, EDAC_MC,
+ "Failed to get %s irq\n",
+ irq == 0 ? "CE" : "UE");
+ ret = -ENODEV;
+ goto err;
+ }
+
+ dmc520_edac_isr = (irq == 0 ? dmc520_edac_ce_isr :
+ dmc520_edac_ue_isr);
+
+ ret = devm_request_irq(&pdev->dev,
+ irq_id,
+ dmc520_edac_isr,
+ 0,
+ dev_name(&pdev->dev),
+ mci);
+ if (ret < 0) {
+ edac_printk(KERN_ERR, EDAC_MC,
+ "Failed to request irq %d\n", irq_id);
+ goto err;
+ }
+ }
+
+ /* Check ECC CE/UE errors */
+ dmc520_handle_ecc_errors(mci, true, false);
+ dmc520_handle_ecc_errors(mci, false, false);
+
+ /* Enable interrupts */
+ dmc520_write_reg(edac,
+ DRAM_ECC_INT_CE_MASK | DRAM_ECC_INT_UE_MASK,
+ REG_OFFSET_INTERRUPT_CONTROL);
+
+ return 0;
+
+err:
+ edac_mc_free(mci);
+
+ return ret;
+}
+
+static int dmc520_edac_remove(struct platform_device *pdev)
+{
+ struct dmc520_edac *edac;
+ struct mem_ctl_info *mci;
+
+ mci = platform_get_drvdata(pdev);
+ edac = mci->pvt_info;
+
+ /* Disable interrupts */
+ dmc520_write_reg(edac,
+ DRAM_ECC_INT_CE_MASK | DRAM_ECC_INT_UE_MASK,
+ REG_OFFSET_INTERRUPT_CONTROL);
+
+ edac_mc_del_mc(&pdev->dev);
+ edac_mc_free(mci);
+
+ return 0;
+}
+
+static const struct of_device_id dmc520_edac_driver_id[] = {
+ { .compatible = "arm,dmc-520", },
+ { /* end of table */ }
+};
+
+MODULE_DEVICE_TABLE(of, dmc520_edac_driver_id);
+
+static struct platform_driver dmc520_edac_driver = {
+ .driver = {
+ .name = "dmc520",
+ .of_match_table = dmc520_edac_driver_id,
+ },
+
+ .probe = dmc520_edac_probe,
+ .remove = dmc520_edac_remove
+};
+
+module_platform_driver(dmc520_edac_driver);
+
+MODULE_AUTHOR("Rui Zhao <ruiz...@microsoft.com>");
+MODULE_DESCRIPTION("DMC-520 ECC driver");
+MODULE_LICENSE("GPL v2");
--
2.19.1
