edac x38: new MC driver module

I wrote a new module for Intel X38 chipset.  This chipset is very similar
to Intel 3200 chipset, but there are some different points, so I copyed
i3200_edac.c and modified.

This is Intel's web page describing this chipset.
http://www.intel.com/Products/Desktop/Chipsets/X38/X38-overview.htm

I've tested this new module with broken memory, and it seems to be working
well.

Signed-off-by: Hitoshi Mitake <mitake@clustcom.com>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 532 insertions, 0 deletions

diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 5a11e3cbcae2..e0dbd388757f 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -102,6 +102,13 @@ config EDAC_I3000
           Support for error detection and correction on the Intel
           3000 and 3010 server chipsets.
 
+config EDAC_X38
+        tristate "Intel X38"
+        depends on EDAC_MM_EDAC && PCI && X86
+        help
+          Support for error detection and correction on the Intel
+          X38 server chipsets.
+
 config EDAC_I82860
         tristate "Intel 82860"
         depends on EDAC_MM_EDAC && PCI && X86_32
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index e5e9104b5520..62c2d9bad8dc 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_EDAC_I82443BXGX)		+= i82443bxgx_edac.o
 obj-$(CONFIG_EDAC_I82875P)              += i82875p_edac.o
 obj-$(CONFIG_EDAC_I82975X)              += i82975x_edac.o
 obj-$(CONFIG_EDAC_I3000)                += i3000_edac.o
+obj-$(CONFIG_EDAC_X38)                  += x38_edac.o
 obj-$(CONFIG_EDAC_I82860)               += i82860_edac.o
 obj-$(CONFIG_EDAC_R82600)               += r82600_edac.o
 obj-$(CONFIG_EDAC_PASEMI)               += pasemi_edac.o
diff --git a/drivers/edac/x38_edac.c b/drivers/edac/x38_edac.c
new file mode 100644
index 000000000000..2406c2ce2844
--- /dev/null
+++ b/drivers/edac/x38_edac.c
@@ -0,0 +1,524 @@
+/*
+ * Intel X38 Memory Controller kernel module
+ * Copyright (C) 2008 Cluster Computing, Inc.
+ *
+ * This file may be distributed under the terms of the
+ * GNU General Public License.
+ *
+ * This file is based on i3200_edac.c
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+#include <linux/slab.h>
+#include <linux/edac.h>
+#include "edac_core.h"
+
+#define X38_REVISION            "1.1"
+
+#define EDAC_MOD_STR            "x38_edac"
+
+#define PCI_DEVICE_ID_INTEL_X38_HB      0x29e0
+
+#define X38_RANKS               8
+#define X38_RANKS_PER_CHANNEL   4
+#define X38_CHANNELS            2
+
+/* Intel X38 register addresses - device 0 function 0 - DRAM Controller */
+
+#define X38_MCHBAR_LOW  0x48    /* MCH Memory Mapped Register BAR */
+#define X38_MCHBAR_HIGH 0x4b
+#define X38_MCHBAR_MASK 0xfffffc000ULL  /* bits 35:14 */
+#define X38_MMR_WINDOW_SIZE     16384
+
+#define X38_TOM 0xa0    /* Top of Memory (16b)
+                                 *
+                                 * 15:10 reserved
+                                 *  9:0  total populated physical memory
+                                 */
+#define X38_TOM_MASK    0x3ff   /* bits 9:0 */
+#define X38_TOM_SHIFT 26        /* 64MiB grain */
+
+#define X38_ERRSTS      0xc8    /* 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 X38_ERRSTS_UE           0x0002
+#define X38_ERRSTS_CE           0x0001
+#define X38_ERRSTS_BITS (X38_ERRSTS_UE | X38_ERRSTS_CE)
+
+
+/* Intel  MMIO register space - device 0 function 0 - MMR space */
+
+#define X38_C0DRB       0x200   /* Channel 0 DRAM Rank Boundary (16b x 4)
+                                 *
+                                 * 15:10 reserved
+                                 *  9:0  Channel 0 DRAM Rank Boundary Address
+                                 */
+#define X38_C1DRB       0x600   /* Channel 1 DRAM Rank Boundary (16b x 4) */
+#define X38_DRB_MASK    0x3ff   /* bits 9:0 */
+#define X38_DRB_SHIFT 26        /* 64MiB grain */
+
+#define X38_C0ECCERRLOG 0x280   /* 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 X38_C1ECCERRLOG 0x680   /* Channel 1 ECC Error Log (64b) */
+#define X38_ECCERRLOG_CE        0x1
+#define X38_ECCERRLOG_UE        0x2
+#define X38_ECCERRLOG_RANK_BITS 0x18000000
+#define X38_ECCERRLOG_SYNDROME_BITS     0xff0000
+
+#define X38_CAPID0 0xe0 /* see P.94 of spec for details */
+
+static int x38_channel_num;
+
+static int how_many_channel(struct pci_dev *pdev)
+{
+        unsigned char capid0_8b; /* 8th byte of CAPID0 */
+
+        pci_read_config_byte(pdev, X38_CAPID0 + 8, &capid0_8b);
+        if (capid0_8b & 0x20) { /* check DCD: Dual Channel Disable */
+                debugf0("In single channel mode.\n");
+                x38_channel_num = 1;
+        } else {
+                debugf0("In dual channel mode.\n");
+                x38_channel_num = 2;
+        }
+
+        return x38_channel_num;
+}
+
+static unsigned long eccerrlog_syndrome(u64 log)
+{
+        return (log & X38_ECCERRLOG_SYNDROME_BITS) >> 16;
+}
+
+static int eccerrlog_row(int channel, u64 log)
+{
+        return ((log & X38_ECCERRLOG_RANK_BITS) >> 27) |
+                (channel * X38_RANKS_PER_CHANNEL);
+}
+
+enum x38_chips {
+        X38 = 0,
+};
+
+struct x38_dev_info {
+        const char *ctl_name;
+};
+
+struct x38_error_info {
+        u16 errsts;
+        u16 errsts2;
+        u64 eccerrlog[X38_CHANNELS];
+};
+
+static const struct x38_dev_info x38_devs[] = {
+        [X38] = {
+                .ctl_name = "x38"},
+};
+
+static struct pci_dev *mci_pdev;
+static int x38_registered = 1;
+
+
+static void x38_clear_error_info(struct mem_ctl_info *mci)
+{
+        struct pci_dev *pdev;
+
+        pdev = to_pci_dev(mci->dev);
+
+        /*
+         * Clear any error bits.
+         * (Yes, we really clear bits by writing 1 to them.)
+         */
+        pci_write_bits16(pdev, X38_ERRSTS, X38_ERRSTS_BITS,
+                         X38_ERRSTS_BITS);
+}
+
+static u64 x38_readq(const void __iomem *addr)
+{
+        return readl(addr) | (((u64)readl(addr + 4)) << 32);
+}
+
+static void x38_get_and_clear_error_info(struct mem_ctl_info *mci,
+                                 struct x38_error_info *info)
+{
+        struct pci_dev *pdev;
+        void __iomem *window = mci->pvt_info;
+
+        pdev = to_pci_dev(mci->dev);
+
+        /*
+         * 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, X38_ERRSTS, &info->errsts);
+        if (!(info->errsts & X38_ERRSTS_BITS))
+                return;
+
+        info->eccerrlog[0] = x38_readq(window + X38_C0ECCERRLOG);
+        if (x38_channel_num == 2)
+                info->eccerrlog[1] = x38_readq(window + X38_C1ECCERRLOG);
+
+        pci_read_config_word(pdev, X38_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) & X38_ERRSTS_BITS) {
+                info->eccerrlog[0] = x38_readq(window + X38_C0ECCERRLOG);
+                if (x38_channel_num == 2)
+                        info->eccerrlog[1] =
+                                x38_readq(window + X38_C1ECCERRLOG);
+        }
+
+        x38_clear_error_info(mci);
+}
+
+static void x38_process_error_info(struct mem_ctl_info *mci,
+                                struct x38_error_info *info)
+{
+        int channel;
+        u64 log;
+
+        if (!(info->errsts & X38_ERRSTS_BITS))
+                return;
+
+        if ((info->errsts ^ info->errsts2) & X38_ERRSTS_BITS) {
+                edac_mc_handle_ce_no_info(mci, "UE overwrote CE");
+                info->errsts = info->errsts2;
+        }
+
+        for (channel = 0; channel < x38_channel_num; channel++) {
+                log = info->eccerrlog[channel];
+                if (log & X38_ECCERRLOG_UE) {
+                        edac_mc_handle_ue(mci, 0, 0,
+                                eccerrlog_row(channel, log), "x38 UE");
+                } else if (log & X38_ECCERRLOG_CE) {
+                        edac_mc_handle_ce(mci, 0, 0,
+                                eccerrlog_syndrome(log),
+                                eccerrlog_row(channel, log), 0, "x38 CE");
+                }
+        }
+}
+
+static void x38_check(struct mem_ctl_info *mci)
+{
+        struct x38_error_info info;
+
+        debugf1("MC%d: %s()\n", mci->mc_idx, __func__);
+        x38_get_and_clear_error_info(mci, &info);
+        x38_process_error_info(mci, &info);
+}
+
+
+void __iomem *x38_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, X38_MCHBAR_LOW, &u.mchbar_low);
+        pci_write_config_dword(pdev, X38_MCHBAR_LOW, u.mchbar_low | 0x1);
+        pci_read_config_dword(pdev, X38_MCHBAR_HIGH, &u.mchbar_high);
+        u.mchbar &= X38_MCHBAR_MASK;
+
+        if (u.mchbar != (resource_size_t)u.mchbar) {
+                printk(KERN_ERR
+                        "x38: mmio space beyond accessible range (0x%llx)\n",
+                        (unsigned long long)u.mchbar);
+                return NULL;
+        }
+
+        window = ioremap_nocache(u.mchbar, X38_MMR_WINDOW_SIZE);
+        if (!window)
+                printk(KERN_ERR "x38: cannot map mmio space at 0x%llx\n",
+                        (unsigned long long)u.mchbar);
+
+        return window;
+}
+
+
+static void x38_get_drbs(void __iomem *window,
+                        u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL])
+{
+        int i;
+
+        for (i = 0; i < X38_RANKS_PER_CHANNEL; i++) {
+                drbs[0][i] = readw(window + X38_C0DRB + 2*i) & X38_DRB_MASK;
+                drbs[1][i] = readw(window + X38_C1DRB + 2*i) & X38_DRB_MASK;
+        }
+}
+
+static bool x38_is_stacked(struct pci_dev *pdev,
+                        u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL])
+{
+        u16 tom;
+
+        pci_read_config_word(pdev, X38_TOM, &tom);
+        tom &= X38_TOM_MASK;
+
+        return drbs[X38_CHANNELS - 1][X38_RANKS_PER_CHANNEL - 1] == tom;
+}
+
+static unsigned long drb_to_nr_pages(
+                        u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL],
+                        bool stacked, int channel, int rank)
+{
+        int n;
+
+        n = drbs[channel][rank];
+        if (rank > 0)
+                n -= drbs[channel][rank - 1];
+        if (stacked && (channel == 1) && drbs[channel][rank] ==
+                                drbs[channel][X38_RANKS_PER_CHANNEL - 1]) {
+                n -= drbs[0][X38_RANKS_PER_CHANNEL - 1];
+        }
+
+        n <<= (X38_DRB_SHIFT - PAGE_SHIFT);
+        return n;
+}
+
+static int x38_probe1(struct pci_dev *pdev, int dev_idx)
+{
+        int rc;
+        int i;
+        struct mem_ctl_info *mci = NULL;
+        unsigned long last_page;
+        u16 drbs[X38_CHANNELS][X38_RANKS_PER_CHANNEL];
+        bool stacked;
+        void __iomem *window;
+
+        debugf0("MC: %s()\n", __func__);
+
+        window = x38_map_mchbar(pdev);
+        if (!window)
+                return -ENODEV;
+
+        x38_get_drbs(window, drbs);
+
+        how_many_channel(pdev);
+
+        /* FIXME: unconventional pvt_info usage */
+        mci = edac_mc_alloc(0, X38_RANKS, x38_channel_num, 0);
+        if (!mci)
+                return -ENOMEM;
+
+        debugf3("MC: %s(): init mci\n", __func__);
+
+        mci->dev = &pdev->dev;
+        mci->mtype_cap = MEM_FLAG_DDR2;
+
+        mci->edac_ctl_cap = EDAC_FLAG_SECDED;
+        mci->edac_cap = EDAC_FLAG_SECDED;
+
+        mci->mod_name = EDAC_MOD_STR;
+        mci->mod_ver = X38_REVISION;
+        mci->ctl_name = x38_devs[dev_idx].ctl_name;
+        mci->dev_name = pci_name(pdev);
+        mci->edac_check = x38_check;
+        mci->ctl_page_to_phys = NULL;
+        mci->pvt_info = window;
+
+        stacked = x38_is_stacked(pdev, drbs);
+
+        /*
+         * 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.
+         */
+        last_page = -1UL;
+        for (i = 0; i < mci->nr_csrows; i++) {
+                unsigned long nr_pages;
+                struct csrow_info *csrow = &mci->csrows[i];
+
+                nr_pages = drb_to_nr_pages(drbs, stacked,
+                        i / X38_RANKS_PER_CHANNEL,
+                        i % X38_RANKS_PER_CHANNEL);
+
+                if (nr_pages == 0) {
+                        csrow->mtype = MEM_EMPTY;
+                        continue;
+                }
+
+                csrow->first_page = last_page + 1;
+                last_page += nr_pages;
+                csrow->last_page = last_page;
+                csrow->nr_pages = nr_pages;
+
+                csrow->grain = nr_pages << PAGE_SHIFT;
+                csrow->mtype = MEM_DDR2;
+                csrow->dtype = DEV_UNKNOWN;
+                csrow->edac_mode = EDAC_UNKNOWN;
+        }
+
+        x38_clear_error_info(mci);
+
+        rc = -ENODEV;
+        if (edac_mc_add_mc(mci)) {
+                debugf3("MC: %s(): failed edac_mc_add_mc()\n", __func__);
+                goto fail;
+        }
+
+        /* get this far and it's successful */
+        debugf3("MC: %s(): success\n", __func__);
+        return 0;
+
+fail:
+        iounmap(window);
+        if (mci)
+                edac_mc_free(mci);
+
+        return rc;
+}
+
+static int __devinit x38_init_one(struct pci_dev *pdev,
+                                const struct pci_device_id *ent)
+{
+        int rc;
+
+        debugf0("MC: %s()\n", __func__);
+
+        if (pci_enable_device(pdev) < 0)
+                return -EIO;
+
+        rc = x38_probe1(pdev, ent->driver_data);
+        if (!mci_pdev)
+                mci_pdev = pci_dev_get(pdev);
+
+        return rc;
+}
+
+static void __devexit x38_remove_one(struct pci_dev *pdev)
+{
+        struct mem_ctl_info *mci;
+
+        debugf0("%s()\n", __func__);
+
+        mci = edac_mc_del_mc(&pdev->dev);
+        if (!mci)
+                return;
+
+        iounmap(mci->pvt_info);
+
+        edac_mc_free(mci);
+}
+
+static const struct pci_device_id x38_pci_tbl[] __devinitdata = {
+        {
+         PCI_VEND_DEV(INTEL, X38_HB), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+         X38},
+        {
+         0,
+         }                      /* 0 terminated list. */
+};
+
+MODULE_DEVICE_TABLE(pci, x38_pci_tbl);
+
+static struct pci_driver x38_driver = {
+        .name = EDAC_MOD_STR,
+        .probe = x38_init_one,
+        .remove = __devexit_p(x38_remove_one),
+        .id_table = x38_pci_tbl,
+};
+
+static int __init x38_init(void)
+{
+        int pci_rc;
+
+        debugf3("MC: %s()\n", __func__);
+
+        /* Ensure that the OPSTATE is set correctly for POLL or NMI */
+        opstate_init();
+
+        pci_rc = pci_register_driver(&x38_driver);
+        if (pci_rc < 0)
+                goto fail0;
+
+        if (!mci_pdev) {
+                x38_registered = 0;
+                mci_pdev = pci_get_device(PCI_VENDOR_ID_INTEL,
+                                        PCI_DEVICE_ID_INTEL_X38_HB, NULL);
+                if (!mci_pdev) {
+                        debugf0("x38 pci_get_device fail\n");
+                        pci_rc = -ENODEV;
+                        goto fail1;
+                }
+
+                pci_rc = x38_init_one(mci_pdev, x38_pci_tbl);
+                if (pci_rc < 0) {
+                        debugf0("x38 init fail\n");
+                        pci_rc = -ENODEV;
+                        goto fail1;
+                }
+        }
+
+        return 0;
+
+fail1:
+        pci_unregister_driver(&x38_driver);
+
+fail0:
+        if (mci_pdev)
+                pci_dev_put(mci_pdev);
+
+        return pci_rc;
+}
+
+static void __exit x38_exit(void)
+{
+        debugf3("MC: %s()\n", __func__);
+
+        pci_unregister_driver(&x38_driver);
+        if (!x38_registered) {
+                x38_remove_one(mci_pdev);
+                pci_dev_put(mci_pdev);
+        }
+}
+
+module_init(x38_init);
+module_exit(x38_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Cluster Computing, Inc. Hitoshi Mitake");
+MODULE_DESCRIPTION("MC support for Intel X38 memory hub controllers");
+
+module_param(edac_op_state, int, 0444);
+MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");