[PATCH v4 2/2] Loongarch: EDAC driver for loongson memory controller

From: Zhao Qunqin
Date: Sun Sep 08 2024 - 23:21:40 EST

Reports single bit errors (CE) only.

Signed-off-by: Zhao Qunqin <zhaoqunqin@xxxxxxxxxxx>
---
Changes in v4:
- None

Changes in v3:
- Addressed review comments raised by Krzysztof and Huacai

Changes in v2:
- Addressed review comments raised by Krzysztof

MAINTAINERS | 1 +
arch/loongarch/Kconfig | 1 +
drivers/edac/Kconfig | 8 ++
drivers/edac/Makefile | 1 +
drivers/edac/loongson_edac.c | 182 +++++++++++++++++++++++++++++++++++
5 files changed, 193 insertions(+)
create mode 100644 drivers/edac/loongson_edac.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 6cc8cfc8f..5b4526638 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13242,6 +13242,7 @@ M: Zhao Qunqin <zhaoqunqin@xxxxxxxxxxx>
L: linux-edac@xxxxxxxxxxxxxxx
S: Maintained
F: Documentation/devicetree/bindings/edac/loongson,ls3a5000-mc-edac.yaml
+F: drivers/edac/loongson_edac.c

LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
M: Sathya Prakash <sathya.prakash@xxxxxxxxxxxx>
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 70f169210..9c135f1a2 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -181,6 +181,7 @@ config LOONGARCH
select PCI_MSI_ARCH_FALLBACKS
select PCI_QUIRKS
select PERF_USE_VMALLOC
+ select EDAC_SUPPORT
select RTC_LIB
select SPARSE_IRQ
select SYSCTL_ARCH_UNALIGN_ALLOW
diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 81af6c344..719bb6ca7 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -564,5 +564,13 @@ config EDAC_VERSAL
Support injecting both correctable and uncorrectable errors
for debugging purposes.

+config EDAC_LOONGSON3
+ tristate "Loongson-3 Memory Controller"
+ depends on LOONGARCH || COMPILE_TEST
+ help
+ Support for error detection and correction on the Loongson-3
+ family memory controller. This driver reports single bit
+ errors (CE) only. Loongson-3A5000/3C5000/3D5000/3C5000L/3A6000/3C6000
+ are compatible.

endif # EDAC
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index faf310eec..e72ca1be4 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -88,3 +88,4 @@ obj-$(CONFIG_EDAC_DMC520) += dmc520_edac.o
obj-$(CONFIG_EDAC_NPCM) += npcm_edac.o
obj-$(CONFIG_EDAC_ZYNQMP) += zynqmp_edac.o
obj-$(CONFIG_EDAC_VERSAL) += versal_edac.o
+obj-$(CONFIG_EDAC_LOONGSON3) += loongson_edac.o
diff --git a/drivers/edac/loongson_edac.c b/drivers/edac/loongson_edac.c
new file mode 100644
index 000000000..b89d6e0e7
--- /dev/null
+++ b/drivers/edac/loongson_edac.c
@@ -0,0 +1,182 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Loongson Technology Corporation Limited.
+ */
+
+#include <linux/edac.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+
+#include "edac_module.h"
+
+enum ecc_index {
+ ECC_SET = 0,
+ ECC_RESERVED,
+ ECC_COUNT,
+ ECC_CS_COUNT,
+ ECC_CODE,
+ ECC_ADDR,
+ ECC_DATA0,
+ ECC_DATA1,
+ ECC_DATA2,
+ ECC_DATA3,
+};
+
+struct loongson_edac_pvt {
+ u64 *ecc_base;
+ int last_ce_count;
+};
+
+static void loongson_update_ce_count(struct mem_ctl_info *mci,
+ int chan,
+ int new)
+{
+ int add;
+ struct loongson_edac_pvt *pvt = mci->pvt_info;
+
+ add = new - pvt->last_ce_count;
+
+ /* Store the new value */
+ pvt->last_ce_count = new;
+
+ /* device resume or any other exceptions*/
+ if (add < 0)
+ return;
+
+ /*updated the edac core */
+ if (add != 0) {
+ edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, add,
+ 0, 0, 0,
+ chan, 0, -1, "error", "");
+ edac_mc_printk(mci, KERN_INFO, "add: %d", add);
+ }
+}
+
+static int loongson_read_ecc(struct mem_ctl_info *mci)
+{
+ u64 ecc;
+ int cs = 0;
+ struct loongson_edac_pvt *pvt = mci->pvt_info;
+
+ if (!pvt->ecc_base)
+ return pvt->last_ce_count;
+
+ ecc = pvt->ecc_base[ECC_CS_COUNT];
+ cs += ecc & 0xff; // cs0
+ cs += (ecc >> 8) & 0xff; // cs1
+ cs += (ecc >> 16) & 0xff; // cs2
+ cs += (ecc >> 24) & 0xff; // cs3
+
+ return cs;
+}
+
+static void loongson_edac_check(struct mem_ctl_info *mci)
+{
+ loongson_update_ce_count(mci, 0, loongson_read_ecc(mci));
+}
+
+static int get_dimm_config(struct mem_ctl_info *mci)
+{
+ u32 size, npages;
+ struct dimm_info *dimm;
+
+ /* size not used */
+ size = -1;
+ npages = MiB_TO_PAGES(size);
+
+ dimm = edac_get_dimm(mci, 0, 0, 0);
+ dimm->nr_pages = npages;
+ snprintf(dimm->label, sizeof(dimm->label),
+ "MC#%uChannel#%u_DIMM#%u",
+ mci->mc_idx, 0, 0);
+ dimm->grain = 8;
+
+ return 0;
+}
+
+static void loongson_pvt_init(struct mem_ctl_info *mci, u64 *vbase)
+{
+ struct loongson_edac_pvt *pvt = mci->pvt_info;
+
+ pvt->ecc_base = vbase;
+ pvt->last_ce_count = loongson_read_ecc(mci);
+}
+
+static int loongson_edac_probe(struct platform_device *pdev)
+{
+ struct mem_ctl_info *mci;
+ struct edac_mc_layer layers[2];
+ struct loongson_edac_pvt *pvt;
+ u64 *vbase = NULL;
+ int ret;
+
+ vbase = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(vbase))
+ return PTR_ERR(vbase);
+
+ /* allocate a new MC control structure */
+ layers[0].type = EDAC_MC_LAYER_CHANNEL;
+ layers[0].size = 1;
+ layers[0].is_virt_csrow = false;
+ layers[1].type = EDAC_MC_LAYER_SLOT;
+ layers[1].size = 1;
+ layers[1].is_virt_csrow = true;
+ mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, sizeof(*pvt));
+ if (mci == NULL)
+ return -ENOMEM;
+
+ mci->mc_idx = edac_device_alloc_index();
+ mci->mtype_cap = MEM_FLAG_RDDR4;
+ mci->edac_ctl_cap = EDAC_FLAG_NONE;
+ mci->edac_cap = EDAC_FLAG_NONE;
+ mci->mod_name = "loongson_edac.c";
+ mci->ctl_name = "loongson_edac_ctl";
+ mci->dev_name = "loongson_edac_dev";
+ mci->ctl_page_to_phys = NULL;
+ mci->pdev = &pdev->dev;
+ mci->error_desc.grain = 8;
+ /* Set the function pointer to an actual operation function */
+ mci->edac_check = loongson_edac_check;
+
+ loongson_pvt_init(mci, vbase);
+ get_dimm_config(mci);
+
+ ret = edac_mc_add_mc(mci);
+ if (ret) {
+ edac_dbg(0, "MC: failed edac_mc_add_mc()\n");
+ edac_mc_free(mci);
+ return ret;
+ }
+ edac_op_state = EDAC_OPSTATE_POLL;
+
+ return 0;
+}
+
+static void loongson_edac_remove(struct platform_device *pdev)
+{
+ struct mem_ctl_info *mci = edac_mc_del_mc(&pdev->dev);
+
+ if (mci)
+ edac_mc_free(mci);
+}
+
+static const struct of_device_id loongson_edac_of_match[] = {
+ { .compatible = "loongson,ls3a5000-mc-edac", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, loongson_edac_of_match);
+
+static struct platform_driver loongson_edac_driver = {
+ .probe = loongson_edac_probe,
+ .remove = loongson_edac_remove,
+ .driver = {
+ .name = "loongson-mc-edac",
+ .of_match_table = loongson_edac_of_match,
+ },
+};
+module_platform_driver(loongson_edac_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Zhao Qunqin <zhaoqunqin@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("EDAC driver for loongson memory controller");
--
2.43.0