1 files changed, 553 insertions, 0 deletions
diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c
new file mode 100644
index 000000000..c8fa7dcfd
--- /dev/null
+++ b/drivers/edac/ghes_edac.c
@@ -0,0 +1,553 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * GHES/EDAC Linux driver
+ *
+ * Copyright (c) 2013 by Mauro Carvalho Chehab
+ *
+ * Red Hat Inc. https://www.redhat.com
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <acpi/ghes.h>
+#include <linux/edac.h>
+#include <linux/dmi.h>
+#include "edac_module.h"
+#include <ras/ras_event.h>
+
+#define OTHER_DETAIL_LEN	400
+
+struct ghes_pvt {
+	struct mem_ctl_info *mci;
+
+	/* Buffers for the error handling routine */
+	char other_detail[OTHER_DETAIL_LEN];
+	char msg[80];
+};
+
+static refcount_t ghes_refcount = REFCOUNT_INIT(0);
+
+/*
+ * Access to ghes_pvt must be protected by ghes_lock. The spinlock
+ * also provides the necessary (implicit) memory barrier for the SMP
+ * case to make the pointer visible on another CPU.
+ */
+static struct ghes_pvt *ghes_pvt;
+
+/*
+ * This driver's representation of the system hardware, as collected
+ * from DMI.
+ */
+static struct ghes_hw_desc {
+	int num_dimms;
+	struct dimm_info *dimms;
+} ghes_hw;
+
+/* GHES registration mutex */
+static DEFINE_MUTEX(ghes_reg_mutex);
+
+/*
+ * Sync with other, potentially concurrent callers of
+ * ghes_edac_report_mem_error(). We don't know what the
+ * "inventive" firmware would do.
+ */
+static DEFINE_SPINLOCK(ghes_lock);
+
+/* "ghes_edac.force_load=1" skips the platform check */
+static bool __read_mostly force_load;
+module_param(force_load, bool, 0);
+
+static bool system_scanned;
+
+/* Memory Device - Type 17 of SMBIOS spec */
+struct memdev_dmi_entry {
+	u8 type;
+	u8 length;
+	u16 handle;
+	u16 phys_mem_array_handle;
+	u16 mem_err_info_handle;
+	u16 total_width;
+	u16 data_width;
+	u16 size;
+	u8 form_factor;
+	u8 device_set;
+	u8 device_locator;
+	u8 bank_locator;
+	u8 memory_type;
+	u16 type_detail;
+	u16 speed;
+	u8 manufacturer;
+	u8 serial_number;
+	u8 asset_tag;
+	u8 part_number;
+	u8 attributes;
+	u32 extended_size;
+	u16 conf_mem_clk_speed;
+} __attribute__((__packed__));
+
+static struct dimm_info *find_dimm_by_handle(struct mem_ctl_info *mci, u16 handle)
+{
+	struct dimm_info *dimm;
+
+	mci_for_each_dimm(mci, dimm) {
+		if (dimm->smbios_handle == handle)
+			return dimm;
+	}
+
+	return NULL;
+}
+
+static void dimm_setup_label(struct dimm_info *dimm, u16 handle)
+{
+	const char *bank = NULL, *device = NULL;
+
+	dmi_memdev_name(handle, &bank, &device);
+
+	/*
+	 * Set to a NULL string when both bank and device are zero. In this case,
+	 * the label assigned by default will be preserved.
+	 */
+	snprintf(dimm->label, sizeof(dimm->label), "%s%s%s",
+		 (bank && *bank) ? bank : "",
+		 (bank && *bank && device && *device) ? " " : "",
+		 (device && *device) ? device : "");
+}
+
+static void assign_dmi_dimm_info(struct dimm_info *dimm, struct memdev_dmi_entry *entry)
+{
+	u16 rdr_mask = BIT(7) | BIT(13);
+
+	if (entry->size == 0xffff) {
+		pr_info("Can't get DIMM%i size\n", dimm->idx);
+		dimm->nr_pages = MiB_TO_PAGES(32);/* Unknown */
+	} else if (entry->size == 0x7fff) {
+		dimm->nr_pages = MiB_TO_PAGES(entry->extended_size);
+	} else {
+		if (entry->size & BIT(15))
+			dimm->nr_pages = MiB_TO_PAGES((entry->size & 0x7fff) << 10);
+		else
+			dimm->nr_pages = MiB_TO_PAGES(entry->size);
+	}
+
+	switch (entry->memory_type) {
+	case 0x12:
+		if (entry->type_detail & BIT(13))
+			dimm->mtype = MEM_RDDR;
+		else
+			dimm->mtype = MEM_DDR;
+		break;
+	case 0x13:
+		if (entry->type_detail & BIT(13))
+			dimm->mtype = MEM_RDDR2;
+		else
+			dimm->mtype = MEM_DDR2;
+		break;
+	case 0x14:
+		dimm->mtype = MEM_FB_DDR2;
+		break;
+	case 0x18:
+		if (entry->type_detail & BIT(12))
+			dimm->mtype = MEM_NVDIMM;
+		else if (entry->type_detail & BIT(13))
+			dimm->mtype = MEM_RDDR3;
+		else
+			dimm->mtype = MEM_DDR3;
+		break;
+	case 0x1a:
+		if (entry->type_detail & BIT(12))
+			dimm->mtype = MEM_NVDIMM;
+		else if (entry->type_detail & BIT(13))
+			dimm->mtype = MEM_RDDR4;
+		else
+			dimm->mtype = MEM_DDR4;
+		break;
+	default:
+		if (entry->type_detail & BIT(6))
+			dimm->mtype = MEM_RMBS;
+		else if ((entry->type_detail & rdr_mask) == rdr_mask)
+			dimm->mtype = MEM_RDR;
+		else if (entry->type_detail & BIT(7))
+			dimm->mtype = MEM_SDR;
+		else if (entry->type_detail & BIT(9))
+			dimm->mtype = MEM_EDO;
+		else
+			dimm->mtype = MEM_UNKNOWN;
+	}
+
+	/*
+	 * Actually, we can only detect if the memory has bits for
+	 * checksum or not
+	 */
+	if (entry->total_width == entry->data_width)
+		dimm->edac_mode = EDAC_NONE;
+	else
+		dimm->edac_mode = EDAC_SECDED;
+
+	dimm->dtype = DEV_UNKNOWN;
+	dimm->grain = 128;		/* Likely, worse case */
+
+	dimm_setup_label(dimm, entry->handle);
+
+	if (dimm->nr_pages) {
+		edac_dbg(1, "DIMM%i: %s size = %d MB%s\n",
+			dimm->idx, edac_mem_types[dimm->mtype],
+			PAGES_TO_MiB(dimm->nr_pages),
+			(dimm->edac_mode != EDAC_NONE) ? "(ECC)" : "");
+		edac_dbg(2, "\ttype %d, detail 0x%02x, width %d(total %d)\n",
+			entry->memory_type, entry->type_detail,
+			entry->total_width, entry->data_width);
+	}
+
+	dimm->smbios_handle = entry->handle;
+}
+
+static void enumerate_dimms(const struct dmi_header *dh, void *arg)
+{
+	struct memdev_dmi_entry *entry = (struct memdev_dmi_entry *)dh;
+	struct ghes_hw_desc *hw = (struct ghes_hw_desc *)arg;
+	struct dimm_info *d;
+
+	if (dh->type != DMI_ENTRY_MEM_DEVICE)
+		return;
+
+	/* Enlarge the array with additional 16 */
+	if (!hw->num_dimms || !(hw->num_dimms % 16)) {
+		struct dimm_info *new;
+
+		new = krealloc_array(hw->dimms, hw->num_dimms + 16,
+				     sizeof(struct dimm_info), GFP_KERNEL);
+		if (!new) {
+			WARN_ON_ONCE(1);
+			return;
+		}
+
+		hw->dimms = new;
+	}
+
+	d = &hw->dimms[hw->num_dimms];
+	d->idx = hw->num_dimms;
+
+	assign_dmi_dimm_info(d, entry);
+
+	hw->num_dimms++;
+}
+
+static void ghes_scan_system(void)
+{
+	if (system_scanned)
+		return;
+
+	dmi_walk(enumerate_dimms, &ghes_hw);
+
+	system_scanned = true;
+}
+
+static int print_mem_error_other_detail(const struct cper_sec_mem_err *mem, char *msg,
+					const char *location, unsigned int len)
+{
+	u32 n;
+
+	if (!msg)
+		return 0;
+
+	n = 0;
+	len -= 1;
+
+	n += scnprintf(msg + n, len - n, "APEI location: %s ", location);
+
+	if (!(mem->validation_bits & CPER_MEM_VALID_ERROR_STATUS))
+		goto out;
+
+	n += scnprintf(msg + n, len - n, "status(0x%016llx): ", mem->error_status);
+	n += scnprintf(msg + n, len - n, "%s ", cper_mem_err_status_str(mem->error_status));
+
+out:
+	msg[n] = '\0';
+
+	return n;
+}
+
+void ghes_edac_report_mem_error(int sev, struct cper_sec_mem_err *mem_err)
+{
+	struct cper_mem_err_compact cmem;
+	struct edac_raw_error_desc *e;
+	struct mem_ctl_info *mci;
+	struct ghes_pvt *pvt;
+	unsigned long flags;
+	char *p;
+
+	/*
+	 * We can do the locking below because GHES defers error processing
+	 * from NMI to IRQ context. Whenever that changes, we'd at least
+	 * know.
+	 */
+	if (WARN_ON_ONCE(in_nmi()))
+		return;
+
+	spin_lock_irqsave(&ghes_lock, flags);
+
+	pvt = ghes_pvt;
+	if (!pvt)
+		goto unlock;
+
+	mci = pvt->mci;
+	e = &mci->error_desc;
+
+	/* Cleans the error report buffer */
+	memset(e, 0, sizeof (*e));
+	e->error_count = 1;
+	e->grain = 1;
+	e->msg = pvt->msg;
+	e->other_detail = pvt->other_detail;
+	e->top_layer = -1;
+	e->mid_layer = -1;
+	e->low_layer = -1;
+	*pvt->other_detail = '\0';
+	*pvt->msg = '\0';
+
+	switch (sev) {
+	case GHES_SEV_CORRECTED:
+		e->type = HW_EVENT_ERR_CORRECTED;
+		break;
+	case GHES_SEV_RECOVERABLE:
+		e->type = HW_EVENT_ERR_UNCORRECTED;
+		break;
+	case GHES_SEV_PANIC:
+		e->type = HW_EVENT_ERR_FATAL;
+		break;
+	default:
+	case GHES_SEV_NO:
+		e->type = HW_EVENT_ERR_INFO;
+	}
+
+	edac_dbg(1, "error validation_bits: 0x%08llx\n",
+		 (long long)mem_err->validation_bits);
+
+	/* Error type, mapped on e->msg */
+	if (mem_err->validation_bits & CPER_MEM_VALID_ERROR_TYPE) {
+		u8 etype = mem_err->error_type;
+
+		p = pvt->msg;
+		p += snprintf(p, sizeof(pvt->msg), "%s", cper_mem_err_type_str(etype));
+	} else {
+		strcpy(pvt->msg, "unknown error");
+	}
+
+	/* Error address */
+	if (mem_err->validation_bits & CPER_MEM_VALID_PA) {
+		e->page_frame_number = PHYS_PFN(mem_err->physical_addr);
+		e->offset_in_page = offset_in_page(mem_err->physical_addr);
+	}
+
+	/* Error grain */
+	if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
+		e->grain = ~mem_err->physical_addr_mask + 1;
+
+	/* Memory error location, mapped on e->location */
+	p = e->location;
+	cper_mem_err_pack(mem_err, &cmem);
+	p += cper_mem_err_location(&cmem, p);
+
+	if (mem_err->validation_bits & CPER_MEM_VALID_MODULE_HANDLE) {
+		struct dimm_info *dimm;
+
+		p += cper_dimm_err_location(&cmem, p);
+		dimm = find_dimm_by_handle(mci, mem_err->mem_dev_handle);
+		if (dimm) {
+			e->top_layer = dimm->idx;
+			strcpy(e->label, dimm->label);
+		}
+	}
+	if (p > e->location)
+		*(p - 1) = '\0';
+
+	if (!*e->label)
+		strcpy(e->label, "unknown memory");
+
+	/* All other fields are mapped on e->other_detail */
+	p = pvt->other_detail;
+	p += print_mem_error_other_detail(mem_err, p, e->location, OTHER_DETAIL_LEN);
+	if (p > pvt->other_detail)
+		*(p - 1) = '\0';
+
+	edac_raw_mc_handle_error(e);
+
+unlock:
+	spin_unlock_irqrestore(&ghes_lock, flags);
+}
+
+/*
+ * Known systems that are safe to enable this module.
+ */
+static struct acpi_platform_list plat_list[] = {
+	{"HPE   ", "Server  ", 0, ACPI_SIG_FADT, all_versions},
+	{ } /* End */
+};
+
+int ghes_edac_register(struct ghes *ghes, struct device *dev)
+{
+	bool fake = false;
+	struct mem_ctl_info *mci;
+	struct ghes_pvt *pvt;
+	struct edac_mc_layer layers[1];
+	unsigned long flags;
+	int idx = -1;
+	int rc = 0;
+
+	if (IS_ENABLED(CONFIG_X86)) {
+		/* Check if safe to enable on this system */
+		idx = acpi_match_platform_list(plat_list);
+		if (!force_load && idx < 0)
+			return -ENODEV;
+	} else {
+		force_load = true;
+		idx = 0;
+	}
+
+	/* finish another registration/unregistration instance first */
+	mutex_lock(&ghes_reg_mutex);
+
+	/*
+	 * We have only one logical memory controller to which all DIMMs belong.
+	 */
+	if (refcount_inc_not_zero(&ghes_refcount))
+		goto unlock;
+
+	ghes_scan_system();
+
+	/* Check if we've got a bogus BIOS */
+	if (!ghes_hw.num_dimms) {
+		fake = true;
+		ghes_hw.num_dimms = 1;
+	}
+
+	layers[0].type = EDAC_MC_LAYER_ALL_MEM;
+	layers[0].size = ghes_hw.num_dimms;
+	layers[0].is_virt_csrow = true;
+
+	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, sizeof(struct ghes_pvt));
+	if (!mci) {
+		pr_info("Can't allocate memory for EDAC data\n");
+		rc = -ENOMEM;
+		goto unlock;
+	}
+
+	pvt		= mci->pvt_info;
+	pvt->mci	= mci;
+
+	mci->pdev = dev;
+	mci->mtype_cap = MEM_FLAG_EMPTY;
+	mci->edac_ctl_cap = EDAC_FLAG_NONE;
+	mci->edac_cap = EDAC_FLAG_NONE;
+	mci->mod_name = "ghes_edac.c";
+	mci->ctl_name = "ghes_edac";
+	mci->dev_name = "ghes";
+
+	if (fake) {
+		pr_info("This system has a very crappy BIOS: It doesn't even list the DIMMS.\n");
+		pr_info("Its SMBIOS info is wrong. It is doubtful that the error report would\n");
+		pr_info("work on such system. Use this driver with caution\n");
+	} else if (idx < 0) {
+		pr_info("This EDAC driver relies on BIOS to enumerate memory and get error reports.\n");
+		pr_info("Unfortunately, not all BIOSes reflect the memory layout correctly.\n");
+		pr_info("So, the end result of using this driver varies from vendor to vendor.\n");
+		pr_info("If you find incorrect reports, please contact your hardware vendor\n");
+		pr_info("to correct its BIOS.\n");
+		pr_info("This system has %d DIMM sockets.\n", ghes_hw.num_dimms);
+	}
+
+	if (!fake) {
+		struct dimm_info *src, *dst;
+		int i = 0;
+
+		mci_for_each_dimm(mci, dst) {
+			src = &ghes_hw.dimms[i];
+
+			dst->idx	   = src->idx;
+			dst->smbios_handle = src->smbios_handle;
+			dst->nr_pages	   = src->nr_pages;
+			dst->mtype	   = src->mtype;
+			dst->edac_mode	   = src->edac_mode;
+			dst->dtype	   = src->dtype;
+			dst->grain	   = src->grain;
+
+			/*
+			 * If no src->label, preserve default label assigned
+			 * from EDAC core.
+			 */
+			if (strlen(src->label))
+				memcpy(dst->label, src->label, sizeof(src->label));
+
+			i++;
+		}
+
+	} else {
+		struct dimm_info *dimm = edac_get_dimm(mci, 0, 0, 0);
+
+		dimm->nr_pages = 1;
+		dimm->grain = 128;
+		dimm->mtype = MEM_UNKNOWN;
+		dimm->dtype = DEV_UNKNOWN;
+		dimm->edac_mode = EDAC_SECDED;
+	}
+
+	rc = edac_mc_add_mc(mci);
+	if (rc < 0) {
+		pr_info("Can't register with the EDAC core\n");
+		edac_mc_free(mci);
+		rc = -ENODEV;
+		goto unlock;
+	}
+
+	spin_lock_irqsave(&ghes_lock, flags);
+	ghes_pvt = pvt;
+	spin_unlock_irqrestore(&ghes_lock, flags);
+
+	/* only set on success */
+	refcount_set(&ghes_refcount, 1);
+
+unlock:
+
+	/* Not needed anymore */
+	kfree(ghes_hw.dimms);
+	ghes_hw.dimms = NULL;
+
+	mutex_unlock(&ghes_reg_mutex);
+
+	return rc;
+}
+
+void ghes_edac_unregister(struct ghes *ghes)
+{
+	struct mem_ctl_info *mci;
+	unsigned long flags;
+
+	if (!force_load)
+		return;
+
+	mutex_lock(&ghes_reg_mutex);
+
+	system_scanned = false;
+	memset(&ghes_hw, 0, sizeof(struct ghes_hw_desc));
+
+	if (!refcount_dec_and_test(&ghes_refcount))
+		goto unlock;
+
+	/*
+	 * Wait for the irq handler being finished.
+	 */
+	spin_lock_irqsave(&ghes_lock, flags);
+	mci = ghes_pvt ? ghes_pvt->mci : NULL;
+	ghes_pvt = NULL;
+	spin_unlock_irqrestore(&ghes_lock, flags);
+
+	if (!mci)
+		goto unlock;
+
+	mci = edac_mc_del_mc(mci->pdev);
+	if (mci)
+		edac_mc_free(mci);
+
+unlock:
+	mutex_unlock(&ghes_reg_mutex);
+}