ie31200_edac: Introduce the driver

Add a driver for the E3-1200 series of Intel DRAM controllers, based on
the following E3-1200 specs:

http://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200-family-vol-2-datasheet.html
http://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200v3-vol-2-datasheet.html

I've tested this on bad memory hardware, and observed correlating bad
reads and uncorrected memory errors as reported by the driver.

Tested against:

CPU E3-1270 v3 @ 3.50GHz : 8086:0c08 (haswell)
CPU E3-1270 V2 @ 3.50GHz : 8086:0158 (ivy bridge)
CPU E31270 @ 3.40GHz : 8086:0108 (sandy bridge)

Signed-off-by: Jason Baron <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
[ Boris: realign defines ]
Signed-off-by: Borislav Petkov <[e-mail]>

drivers/edac/Kconfig

···
 	  Support for error detection and correction on the Intel
 	  3200 and 3210 server chipsets.
 
+config EDAC_IE31200
+	tristate "Intel e312xx"
+	depends on EDAC_MM_EDAC && PCI && X86
+	help
+	  Support for error detection and correction on the Intel
+	  E3-1200 based DRAM controllers.
+
 config EDAC_X38
 	tristate "Intel X38"
 	depends on EDAC_MM_EDAC && PCI && X86

drivers/edac/Makefile

···
 obj-$(CONFIG_EDAC_I82975X)		+= i82975x_edac.o
 obj-$(CONFIG_EDAC_I3000)		+= i3000_edac.o
 obj-$(CONFIG_EDAC_I3200)		+= i3200_edac.o
+obj-$(CONFIG_EDAC_IE31200)		+= ie31200_edac.o
 obj-$(CONFIG_EDAC_X38)			+= x38_edac.o
 obj-$(CONFIG_EDAC_I82860)		+= i82860_edac.o
 obj-$(CONFIG_EDAC_R82600)		+= r82600_edac.o

drivers/edac/ie31200_edac.c

···
+/*
+ * Intel E3-1200
+ * Copyright (C) 2014 Jason Baron <[e-mail]>
+ *
+ * Support for the E3-1200 processor family. Heavily based on previous
+ * Intel EDAC drivers.
+ *
+ * Since the DRAM controller is on the cpu chip, we can use its PCI device
+ * id to identify these processors.
+ *
+ * PCI DRAM controller device ids (Taken from The PCI ID Repository - http://pci-ids.ucw.cz/)
+ *
+ * 0108: Xeon E3-1200 Processor Family DRAM Controller
+ * 010c: Xeon E3-1200/2nd Generation Core Processor Family DRAM Controller
+ * 0150: Xeon E3-1200 v2/3rd Gen Core processor DRAM Controller
+ * 0158: Xeon E3-1200 v2/Ivy Bridge DRAM Controller
+ * 015c: Xeon E3-1200 v2/3rd Gen Core processor DRAM Controller
+ * 0c04: Xeon E3-1200 v3/4th Gen Core Processor DRAM Controller
+ * 0c08: Xeon E3-1200 v3 Processor DRAM Controller
+ *
+ * Based on Intel specification:
+ * http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/xeon-e3-1200v3-vol-2-datasheet.pdf
+ * http://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200-family-vol-2-datasheet.html
+ *
+ * According to the above datasheet (p.16):
+ * "
+ * 6. Software must not access B0/D0/F0 32-bit memory-mapped registers with
+ * requests that cross a DW boundary.
+ * "
+ *
+ * Thus, we make use of the explicit: lo_hi_readq(), which breaks the readq into
+ * 2 readl() calls. This restriction may be lifted in subsequent chip releases,
+ * but lo_hi_readq() ensures that we are safe across all e3-1200 processors.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+#include <linux/edac.h>
+
+#include <asm-generic/io-64-nonatomic-lo-hi.h>
+#include "edac_core.h"
+
+#define IE31200_REVISION "1.0"
+#define EDAC_MOD_STR "ie31200_edac"
+
+#define ie31200_printk(level, fmt, arg...) \
+	edac_printk(level, "ie31200", fmt, ##arg)
+
+#define PCI_DEVICE_ID_INTEL_IE31200_HB_1 0x0108
+#define PCI_DEVICE_ID_INTEL_IE31200_HB_2 0x010c
+#define PCI_DEVICE_ID_INTEL_IE31200_HB_3 0x0150
+#define PCI_DEVICE_ID_INTEL_IE31200_HB_4 0x0158
+#define PCI_DEVICE_ID_INTEL_IE31200_HB_5 0x015c
+#define PCI_DEVICE_ID_INTEL_IE31200_HB_6 0x0c04
+#define PCI_DEVICE_ID_INTEL_IE31200_HB_7 0x0c08
+
+#define IE31200_DIMMS			4
+#define IE31200_RANKS			8
+#define IE31200_RANKS_PER_CHANNEL	4
+#define IE31200_DIMMS_PER_CHANNEL	2
+#define IE31200_CHANNELS		2
+
+/* Intel IE31200 register addresses - device 0 function 0 - DRAM Controller */
+#define IE31200_MCHBAR_LOW		0x48
+#define IE31200_MCHBAR_HIGH		0x4c
+#define IE31200_MCHBAR_MASK		GENMASK_ULL(38, 15)
+#define IE31200_MMR_WINDOW_SIZE		BIT(15)
+
+/*
+ * Error Status Register (16b)
+ *
+ * 15    reserved
+ * 14    Isochronous TBWRR Run Behind FIFO Full
+ *       (ITCV)
+ * 13    Isochronous TBWRR Run Behind FIFO Put
+ *       (ITSTV)
+ * 12    reserved
+ * 11    MCH Thermal Sensor Event
+ *       for SMI/SCI/SERR (GTSE)
+ * 10    reserved
+ *  9    LOCK to non-DRAM Memory Flag (LCKF)
+ *  8    reserved
+ *  7    DRAM Throttle Flag (DTF)
+ *  6:2  reserved
+ *  1    Multi-bit DRAM ECC Error Flag (DMERR)
+ *  0    Single-bit DRAM ECC Error Flag (DSERR)
+ */
+#define IE31200_ERRSTS			0xc8
+#define IE31200_ERRSTS_UE		BIT(1)
+#define IE31200_ERRSTS_CE		BIT(0)
+#define IE31200_ERRSTS_BITS		(IE31200_ERRSTS_UE | IE31200_ERRSTS_CE)
+
+/*
+ * Channel 0 ECC Error Log (64b)
+ *
+ * 63:48 Error Column Address (ERRCOL)
+ * 47:32 Error Row Address (ERRROW)
+ * 31:29 Error Bank Address (ERRBANK)
+ * 28:27 Error Rank Address (ERRRANK)
+ * 26:24 reserved
+ * 23:16 Error Syndrome (ERRSYND)
+ * 15: 2 reserved
+ *    1  Multiple Bit Error Status (MERRSTS)
+ *    0  Correctable Error Status (CERRSTS)
+ */
+#define IE31200_C0ECCERRLOG			0x40c8
+#define IE31200_C1ECCERRLOG			0x44c8
+#define IE31200_ECCERRLOG_CE			BIT(0)
+#define IE31200_ECCERRLOG_UE			BIT(1)
+#define IE31200_ECCERRLOG_RANK_BITS		GENMASK_ULL(28, 27)
+#define IE31200_ECCERRLOG_RANK_SHIFT		27
+#define IE31200_ECCERRLOG_SYNDROME_BITS		GENMASK_ULL(23, 16)
+#define IE31200_ECCERRLOG_SYNDROME_SHIFT	16
+
+#define IE31200_ECCERRLOG_SYNDROME(log)		   \
+	((log & IE31200_ECCERRLOG_SYNDROME_BITS) >> \
+	 IE31200_ECCERRLOG_SYNDROME_SHIFT)
+
+#define IE31200_CAPID0			0xe4
+#define IE31200_CAPID0_PDCD		BIT(4)
+#define IE31200_CAPID0_DDPCD		BIT(6)
+#define IE31200_CAPID0_ECC		BIT(1)
+
+#define IE31200_MAD_DIMM_0_OFFSET	0x5004
+#define IE31200_MAD_DIMM_SIZE		GENMASK_ULL(7, 0)
+#define IE31200_MAD_DIMM_A_RANK		BIT(17)
+#define IE31200_MAD_DIMM_A_WIDTH	BIT(19)
+
+#define IE31200_PAGES(n)		(n << (28 - PAGE_SHIFT))
+
+static int nr_channels;
+
+struct ie31200_priv {
+	void __iomem *window;
+};
+
+enum ie31200_chips {
+	IE31200 = 0,
+};
+
+struct ie31200_dev_info {
+	const char *ctl_name;
+};
+
+struct ie31200_error_info {
+	u16 errsts;
+	u16 errsts2;
+	u64 eccerrlog[IE31200_CHANNELS];
+};
+
+static const struct ie31200_dev_info ie31200_devs[] = {
+	[IE31200] = {
+		.ctl_name = "IE31200"
+	},
+};
+
+struct dimm_data {
+	u8 size; /* in 256MB multiples */
+	u8 dual_rank : 1,
+	   x16_width : 1; /* 0 means x8 width */
+};
+
+static int how_many_channels(struct pci_dev *pdev)
+{
+	int n_channels;
+	unsigned char capid0_2b; /* 2nd byte of CAPID0 */
+
+	pci_read_config_byte(pdev, IE31200_CAPID0 + 1, &capid0_2b);
+
+	/* check PDCD: Dual Channel Disable */
+	if (capid0_2b & IE31200_CAPID0_PDCD) {
+		edac_dbg(0, "In single channel mode\n");
+		n_channels = 1;
+	} else {
+		edac_dbg(0, "In dual channel mode\n");
+		n_channels = 2;
+	}
+
+	/* check DDPCD - check if both channels are filled */
+	if (capid0_2b & IE31200_CAPID0_DDPCD)
+		edac_dbg(0, "2 DIMMS per channel disabled\n");
+	else
+		edac_dbg(0, "2 DIMMS per channel enabled\n");
+
+	return n_channels;
+}
+
+static bool ecc_capable(struct pci_dev *pdev)
+{
+	unsigned char capid0_4b; /* 4th byte of CAPID0 */
+
+	pci_read_config_byte(pdev, IE31200_CAPID0 + 3, &capid0_4b);
+	if (capid0_4b & IE31200_CAPID0_ECC)
+		return false;
+	return true;
+}
+
+static int eccerrlog_row(int channel, u64 log)
+{
+	int rank = ((log & IE31200_ECCERRLOG_RANK_BITS) >>
+		IE31200_ECCERRLOG_RANK_SHIFT);
+	return rank | (channel * IE31200_RANKS_PER_CHANNEL);
+}
+
+static void ie31200_clear_error_info(struct mem_ctl_info *mci)
+{
+	/*
+	 * Clear any error bits.
+	 * (Yes, we really clear bits by writing 1 to them.)
+	 */
+	pci_write_bits16(to_pci_dev(mci->pdev), IE31200_ERRSTS,
+			 IE31200_ERRSTS_BITS, IE31200_ERRSTS_BITS);
+}
+
+static void ie31200_get_and_clear_error_info(struct mem_ctl_info *mci,
+					     struct ie31200_error_info *info)
+{
+	struct pci_dev *pdev;
+	struct ie31200_priv *priv = mci->pvt_info;
+	void __iomem *window = priv->window;
+
+	pdev = to_pci_dev(mci->pdev);
+
+	/*
+	 * This is a mess because there is no atomic way to read all the
+	 * registers at once and the registers can transition from CE being
+	 * overwritten by UE.
+	 */
+	pci_read_config_word(pdev, IE31200_ERRSTS, &info->errsts);
+	if (!(info->errsts & IE31200_ERRSTS_BITS))
+		return;
+
+	info->eccerrlog[0] = lo_hi_readq(window + IE31200_C0ECCERRLOG);
+	if (nr_channels == 2)
+		info->eccerrlog[1] = lo_hi_readq(window + IE31200_C1ECCERRLOG);
+
+	pci_read_config_word(pdev, IE31200_ERRSTS, &info->errsts2);
+
+	/*
+	 * If the error is the same for both reads then the first set
+	 * of reads is valid.  If there is a change then there is a CE
+	 * with no info and the second set of reads is valid and
+	 * should be UE info.
+	 */
+	if ((info->errsts ^ info->errsts2) & IE31200_ERRSTS_BITS) {
+		info->eccerrlog[0] = lo_hi_readq(window + IE31200_C0ECCERRLOG);
+		if (nr_channels == 2)
+			info->eccerrlog[1] =
+				lo_hi_readq(window + IE31200_C1ECCERRLOG);
+	}
+
+	ie31200_clear_error_info(mci);
+}
+
+static void ie31200_process_error_info(struct mem_ctl_info *mci,
+				       struct ie31200_error_info *info)
+{
+	int channel;
+	u64 log;
+
+	if (!(info->errsts & IE31200_ERRSTS_BITS))
+		return;
+
+	if ((info->errsts ^ info->errsts2) & IE31200_ERRSTS_BITS) {
+		edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1, 0, 0, 0,
+				     -1, -1, -1, "UE overwrote CE", "");
+		info->errsts = info->errsts2;
+	}
+
+	for (channel = 0; channel < nr_channels; channel++) {
+		log = info->eccerrlog[channel];
+		if (log & IE31200_ECCERRLOG_UE) {
+			edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
+					     0, 0, 0,
+					     eccerrlog_row(channel, log),
+					     channel, -1,
+					     "ie31200 UE", "");
+		} else if (log & IE31200_ECCERRLOG_CE) {
+			edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
+					     0, 0,
+					     IE31200_ECCERRLOG_SYNDROME(log),
+					     eccerrlog_row(channel, log),
+					     channel, -1,
+					     "ie31200 CE", "");
+		}
+	}
+}
+
+static void ie31200_check(struct mem_ctl_info *mci)
+{
+	struct ie31200_error_info info;
+
+	edac_dbg(1, "MC%d\n", mci->mc_idx);
+	ie31200_get_and_clear_error_info(mci, &info);
+	ie31200_process_error_info(mci, &info);
+}
+
+static void __iomem *ie31200_map_mchbar(struct pci_dev *pdev)
+{
+	union {
+		u64 mchbar;
+		struct {
+			u32 mchbar_low;
+			u32 mchbar_high;
+		};
+	} u;
+	void __iomem *window;
+
+	pci_read_config_dword(pdev, IE31200_MCHBAR_LOW, &u.mchbar_low);
+	pci_read_config_dword(pdev, IE31200_MCHBAR_HIGH, &u.mchbar_high);
+	u.mchbar &= IE31200_MCHBAR_MASK;
+
+	if (u.mchbar != (resource_size_t)u.mchbar) {
+		ie31200_printk(KERN_ERR, "mmio space beyond accessible range (0x%llx)\n",
+			       (unsigned long long)u.mchbar);
+		return NULL;
+	}
+
+	window = ioremap_nocache(u.mchbar, IE31200_MMR_WINDOW_SIZE);
+	if (!window)
+		ie31200_printk(KERN_ERR, "Cannot map mmio space at 0x%llx\n",
+			       (unsigned long long)u.mchbar);
+
+	return window;
+}
+
+static int ie31200_probe1(struct pci_dev *pdev, int dev_idx)
+{
+	int rc;
+	int i, j;
+	struct mem_ctl_info *mci = NULL;
+	struct edac_mc_layer layers[2];
+	struct dimm_data dimm_info[IE31200_CHANNELS][IE31200_DIMMS_PER_CHANNEL];
+	void __iomem *window;
+	struct ie31200_priv *priv;
+	u32 addr_decode;
+
+	edac_dbg(0, "MC:\n");
+
+	if (!ecc_capable(pdev)) {
+		ie31200_printk(KERN_INFO, "No ECC support\n");
+		return -ENODEV;
+	}
+
+	window = ie31200_map_mchbar(pdev);
+	if (!window)
+		return -ENODEV;
+
+	/* populate DIMM info */
+	for (i = 0; i < IE31200_CHANNELS; i++) {
+		addr_decode = readl(window + IE31200_MAD_DIMM_0_OFFSET +
+					(i * 4));
+		edac_dbg(0, "addr_decode: 0x%x\n", addr_decode);
+		for (j = 0; j < IE31200_DIMMS_PER_CHANNEL; j++) {
+			dimm_info[i][j].size = (addr_decode >> (j * 8)) &
+						IE31200_MAD_DIMM_SIZE;
+			dimm_info[i][j].dual_rank = (addr_decode &
+				(IE31200_MAD_DIMM_A_RANK << j)) ? 1 : 0;
+			dimm_info[i][j].x16_width = (addr_decode &
+				(IE31200_MAD_DIMM_A_WIDTH << j)) ? 1 : 0;
+			edac_dbg(0, "size: 0x%x, rank: %d, width: %d\n",
+				 dimm_info[i][j].size,
+				 dimm_info[i][j].dual_rank,
+				 dimm_info[i][j].x16_width);
+		}
+	}
+
+	nr_channels = how_many_channels(pdev);
+
+	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
+	layers[0].size = IE31200_DIMMS;
+	layers[0].is_virt_csrow = true;
+	layers[1].type = EDAC_MC_LAYER_CHANNEL;
+	layers[1].size = nr_channels;
+	layers[1].is_virt_csrow = false;
+	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers,
+			    sizeof(struct ie31200_priv));
+
+	rc = -ENOMEM;
+	if (!mci)
+		goto fail_unmap;
+
+	edac_dbg(3, "MC: init mci\n");
+
+	mci->pdev = &pdev->dev;
+	mci->mtype_cap = MEM_FLAG_DDR3;
+
+	mci->edac_ctl_cap = EDAC_FLAG_SECDED;
+	mci->edac_cap = EDAC_FLAG_SECDED;
+
+	mci->mod_name = EDAC_MOD_STR;
+	mci->mod_ver = IE31200_REVISION;
+	mci->ctl_name = ie31200_devs[dev_idx].ctl_name;
+	mci->dev_name = pci_name(pdev);
+	mci->edac_check = ie31200_check;
+	mci->ctl_page_to_phys = NULL;
+	priv = mci->pvt_info;
+	priv->window = window;
+
+	/*
+	 * The dram rank boundary (DRB) reg values are boundary addresses
+	 * for each DRAM rank with a granularity of 64MB.  DRB regs are
+	 * cumulative; the last one will contain the total memory
+	 * contained in all ranks.
+	 */
+	for (i = 0; i < IE31200_DIMMS_PER_CHANNEL; i++) {
+		for (j = 0; j < IE31200_CHANNELS; j++) {
+			struct dimm_info *dimm;
+			unsigned long nr_pages;
+
+			nr_pages = IE31200_PAGES(dimm_info[j][i].size);
+			if (nr_pages == 0)
+				continue;
+
+			if (dimm_info[j][i].dual_rank) {
+				nr_pages = nr_pages / 2;
+				dimm = EDAC_DIMM_PTR(mci->layers, mci->dimms,
+						     mci->n_layers, (i * 2) + 1,
+						     j, 0);
+				dimm->nr_pages = nr_pages;
+				edac_dbg(0, "set nr pages: 0x%lx\n", nr_pages);
+				dimm->grain = 8; /* just a guess */
+				dimm->mtype = MEM_DDR3;
+				dimm->dtype = DEV_UNKNOWN;
+				dimm->edac_mode = EDAC_UNKNOWN;
+			}
+			dimm = EDAC_DIMM_PTR(mci->layers, mci->dimms,
+					     mci->n_layers, i * 2, j, 0);
+			dimm->nr_pages = nr_pages;
+			edac_dbg(0, "set nr pages: 0x%lx\n", nr_pages);
+			dimm->grain = 8; /* same guess */
+			dimm->mtype = MEM_DDR3;
+			dimm->dtype = DEV_UNKNOWN;
+			dimm->edac_mode = EDAC_UNKNOWN;
+		}
+	}
+
+	ie31200_clear_error_info(mci);
+
+	rc = -ENODEV;
+	if (edac_mc_add_mc(mci)) {
+		edac_dbg(3, "MC: failed edac_mc_add_mc()\n");
+		goto fail_free;
+	}
+
+	/* get this far and it's successful */
+	edac_dbg(3, "MC: success\n");
+	return 0;
+
+fail_free:
+	if (mci)
+		edac_mc_free(mci);
+fail_unmap:
+	iounmap(window);
+
+	return rc;
+}
+
+static int ie31200_init_one(struct pci_dev *pdev,
+			    const struct pci_device_id *ent)
+{
+	edac_dbg(0, "MC:\n");
+
+	if (pci_enable_device(pdev) < 0)
+		return -EIO;
+
+	return ie31200_probe1(pdev, ent->driver_data);
+}
+
+static void ie31200_remove_one(struct pci_dev *pdev)
+{
+	struct mem_ctl_info *mci;
+	struct ie31200_priv *priv;
+
+	edac_dbg(0, "\n");
+	mci = edac_mc_del_mc(&pdev->dev);
+	if (!mci)
+		return;
+	priv = mci->pvt_info;
+	iounmap(priv->window);
+	edac_mc_free(mci);
+}
+
+static const struct pci_device_id ie31200_pci_tbl[] = {
+	{
+		PCI_VEND_DEV(INTEL, IE31200_HB_1), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		IE31200},
+	{
+		PCI_VEND_DEV(INTEL, IE31200_HB_2), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		IE31200},
+	{
+		PCI_VEND_DEV(INTEL, IE31200_HB_3), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		IE31200},
+	{
+		PCI_VEND_DEV(INTEL, IE31200_HB_4), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		IE31200},
+	{
+		PCI_VEND_DEV(INTEL, IE31200_HB_5), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		IE31200},
+	{
+		PCI_VEND_DEV(INTEL, IE31200_HB_6), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		IE31200},
+	{
+		PCI_VEND_DEV(INTEL, IE31200_HB_7), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		IE31200},
+	{
+		0,
+	}            /* 0 terminated list. */
+};
+MODULE_DEVICE_TABLE(pci, ie31200_pci_tbl);
+
+static struct pci_driver ie31200_driver = {
+	.name = EDAC_MOD_STR,
+	.probe = ie31200_init_one,
+	.remove = ie31200_remove_one,
+	.id_table = ie31200_pci_tbl,
+};
+
+static int __init ie31200_init(void)
+{
+	edac_dbg(3, "MC:\n");
+	/* Ensure that the OPSTATE is set correctly for POLL or NMI */
+	opstate_init();
+
+	return pci_register_driver(&ie31200_driver);
+}
+
+static void __exit ie31200_exit(void)
+{
+	edac_dbg(3, "MC:\n");
+	pci_unregister_driver(&ie31200_driver);
+}
+
+module_init(ie31200_init);
+module_exit(ie31200_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jason Baron <[e-mail]>");
+MODULE_DESCRIPTION("MC support for Intel Processor E31200 memory hub controllers");