[PATCH 3/3] edac: sifive: Add EDAC support for Memory Controller in SiFive SoCs

[Yash Shah]

Add Memory controller EDAC support in exisiting SiFive platform EDAC
driver. It registers for notifier events from the SiFive DDR controller
driver for DDR ECC events.

Signed-off-by: Yash Shah <yash.shah at sifive.com>
---
 drivers/edac/Kconfig       |   2 +-
 drivers/edac/sifive_edac.c | 117 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 118 insertions(+), 1 deletion(-)

diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 7b6ec30..f8b3b53 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -462,7 +462,7 @@ config EDAC_ALTERA_SDMMC
 
 config EDAC_SIFIVE
 	bool "Sifive platform EDAC driver"
-	depends on EDAC=y && SIFIVE_L2
+	depends on EDAC=y && (SIFIVE_L2 || SIFIVE_DDR)
 	help
 	  Support for error detection and correction on the SiFive SoCs.
 
diff --git a/drivers/edac/sifive_edac.c b/drivers/edac/sifive_edac.c
index 3a3dcb1..cf032685 100644
--- a/drivers/edac/sifive_edac.c
+++ b/drivers/edac/sifive_edac.c
@@ -11,14 +11,120 @@
 #include <linux/platform_device.h>
 #include "edac_module.h"
 #include <soc/sifive/sifive_l2_cache.h>
+#include <soc/sifive/sifive_ddr.h>
 
 #define DRVNAME "sifive_edac"
+#define SIFIVE_EDAC_MOD_NAME "Sifive ECC Manager"
 
 struct sifive_edac_priv {
 	struct notifier_block notifier;
 	struct edac_device_ctl_info *dci;
 };
 
+struct sifive_edac_mc_priv {
+	struct notifier_block notifier;
+	struct mem_ctl_info *mci;
+};
+
+/**
+ * EDAC MC error callback
+ *
+ * @event: non-zero if unrecoverable.
+ */
+static
+int ecc_mc_err_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct sifive_ddr_priv *priv = ptr;
+	struct sifive_edac_mc_priv *p;
+
+	p = container_of(this, struct sifive_edac_mc_priv, notifier);
+	if (event == SIFIVE_DDR_ERR_TYPE_UE) {
+		edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, p->mci,
+				     priv->error_count, priv->page_frame_number,
+				     priv->offset_in_page, priv->syndrome,
+				     priv->top_layer, priv->mid_layer,
+				     priv->low_layer, p->mci->ctl_name, "");
+	} else if (event == SIFIVE_DDR_ERR_TYPE_CE) {
+		edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, p->mci,
+				     priv->error_count, priv->page_frame_number,
+				     priv->offset_in_page, priv->syndrome,
+				     priv->top_layer, priv->mid_layer,
+				     priv->low_layer, p->mci->ctl_name, "");
+	}
+
+	return NOTIFY_OK;
+}
+
+static int ecc_mc_register(struct platform_device *pdev)
+{
+	struct sifive_edac_mc_priv *p;
+	struct edac_mc_layer layers[1];
+	int ret;
+
+	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	p->notifier.notifier_call = ecc_mc_err_event;
+	platform_set_drvdata(pdev, p);
+
+	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
+	layers[0].size = 1;
+	layers[0].is_virt_csrow = true;
+
+	p->mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, 0);
+	if (!p->mci) {
+		dev_err(&pdev->dev, "Failed mem allocation for mc instance\n");
+		return -ENOMEM;
+	}
+
+	p->mci->pdev = &pdev->dev;
+	/* Initialize controller capabilities */
+	p->mci->mtype_cap = MEM_FLAG_DDR4;
+	p->mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
+	p->mci->edac_cap = EDAC_FLAG_SECDED;
+	p->mci->scrub_cap = SCRUB_UNKNOWN;
+	p->mci->scrub_mode = SCRUB_HW_PROG;
+	p->mci->ctl_name = dev_name(&pdev->dev);
+	p->mci->dev_name = dev_name(&pdev->dev);
+	p->mci->mod_name = SIFIVE_EDAC_MOD_NAME;
+	p->mci->ctl_page_to_phys = NULL;
+
+	/* Interrupt feature is supported by cadence mc */
+	edac_op_state = EDAC_OPSTATE_INT;
+
+	ret = edac_mc_add_mc(p->mci);
+	if (ret) {
+		edac_printk(KERN_ERR, SIFIVE_EDAC_MOD_NAME,
+			    "Failed to register with EDAC core\n");
+		goto err;
+	}
+
+#ifdef CONFIG_SIFIVE_DDR
+	register_sifive_ddr_error_notifier(&p->notifier);
+#endif
+
+	return 0;
+
+err:
+	edac_mc_free(p->mci);
+
+	return -ENXIO;
+}
+
+static int ecc_mc_unregister(struct platform_device *pdev)
+{
+	struct sifive_edac_mc_priv *p = platform_get_drvdata(pdev);
+
+#ifdef CONFIG_SIFIVE_DDR
+	unregister_sifive_ddr_error_notifier(&p->notifier);
+#endif
+	edac_mc_del_mc(&pdev->dev);
+	edac_mc_free(p->mci);
+
+	return 0;
+}
+
 /**
  * EDAC error callback
  *
@@ -67,7 +173,9 @@ static int ecc_register(struct platform_device *pdev)
 		goto err;
 	}
 
+#ifdef CONFIG_SIFIVE_L2
 	register_sifive_l2_error_notifier(&p->notifier);
+#endif
 
 	return 0;
 
@@ -81,7 +189,9 @@ static int ecc_unregister(struct platform_device *pdev)
 {
 	struct sifive_edac_priv *p = platform_get_drvdata(pdev);
 
+#ifdef CONFIG_SIFIVE_L2
 	unregister_sifive_l2_error_notifier(&p->notifier);
+#endif
 	edac_device_del_device(&pdev->dev);
 	edac_device_free_ctl_info(p->dci);
 
@@ -102,12 +212,19 @@ static int __init sifive_edac_init(void)
 	if (ret)
 		platform_device_unregister(sifive_pdev);
 
+	ret = ecc_mc_register(sifive_pdev);
+	if (ret) {
+		ecc_unregister(sifive_pdev);
+		platform_device_unregister(sifive_pdev);
+	}
+
 	return ret;
 }
 
 static void __exit sifive_edac_exit(void)
 {
 	ecc_unregister(sifive_pdev);
+	ecc_mc_unregister(sifive_pdev);
 	platform_device_unregister(sifive_pdev);
 }
 
-- 
2.7.4