/*
 * Intel e7xxx Memory Controller kernel module
 * (C) 2003 Linux Networx (http://lnxi.com)
 * This file may be distributed under the terms of the
 * GNU General Public License.
 *
 * See "enum e7xxx_chips" below for supported chipsets
 *
 * Written by Thayne Harbaugh
 * Based on work by Dan Hollis <goemon at anime dot net> and others.
 *      http://www.anime.net/~goemon/linux-ecc/
 *
 * Datasheet:
 *      http://www.intel.com/content/www/us/en/chipsets/e7501-chipset-memory-controller-hub-datasheet.html
 *
 * Contributors:
 *      Eric Biederman (Linux Networx)
 *      Tom Zimmerman (Linux Networx)
 *      Jim Garlick (Lawrence Livermore National Labs)
 *      Dave Peterson (Lawrence Livermore National Labs)
 *      That One Guy (Some other place)
 *      Wang Zhenyu (intel.com)
 *
 * $Id: edac_e7xxx.c,v 1.5.2.9 2005/10/05 00:43:44 dsp_llnl Exp $
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/edac.h>
#include "edac_module.h"

#define EDAC_MOD_STR    "e7xxx_edac"

#define e7xxx_printk(level, fmt, arg...) \
        edac_printk(level, "e7xxx", fmt, ##arg)

#define e7xxx_mc_printk(mci, level, fmt, arg...) \
        edac_mc_chipset_printk(mci, level, "e7xxx", fmt, ##arg)

#ifndef PCI_DEVICE_ID_INTEL_7205_0
#define PCI_DEVICE_ID_INTEL_7205_0      0x255d
#endif                          /* PCI_DEVICE_ID_INTEL_7205_0 */

#ifndef PCI_DEVICE_ID_INTEL_7205_1_ERR
#define PCI_DEVICE_ID_INTEL_7205_1_ERR  0x2551
#endif                          /* PCI_DEVICE_ID_INTEL_7205_1_ERR */

#ifndef PCI_DEVICE_ID_INTEL_7500_0
#define PCI_DEVICE_ID_INTEL_7500_0      0x2540
#endif                          /* PCI_DEVICE_ID_INTEL_7500_0 */

#ifndef PCI_DEVICE_ID_INTEL_7500_1_ERR
#define PCI_DEVICE_ID_INTEL_7500_1_ERR  0x2541
#endif                          /* PCI_DEVICE_ID_INTEL_7500_1_ERR */

#ifndef PCI_DEVICE_ID_INTEL_7501_0
#define PCI_DEVICE_ID_INTEL_7501_0      0x254c
#endif                          /* PCI_DEVICE_ID_INTEL_7501_0 */

#ifndef PCI_DEVICE_ID_INTEL_7501_1_ERR
#define PCI_DEVICE_ID_INTEL_7501_1_ERR  0x2541
#endif                          /* PCI_DEVICE_ID_INTEL_7501_1_ERR */

#ifndef PCI_DEVICE_ID_INTEL_7505_0
#define PCI_DEVICE_ID_INTEL_7505_0      0x2550
#endif                          /* PCI_DEVICE_ID_INTEL_7505_0 */

#ifndef PCI_DEVICE_ID_INTEL_7505_1_ERR
#define PCI_DEVICE_ID_INTEL_7505_1_ERR  0x2551
#endif                          /* PCI_DEVICE_ID_INTEL_7505_1_ERR */

#define E7XXX_NR_CSROWS         8       /* number of csrows */
#define E7XXX_NR_DIMMS          8       /* 2 channels, 4 dimms/channel */

/* E7XXX register addresses - device 0 function 0 */
#define E7XXX_DRB               0x60    /* DRAM row boundary register (8b) */
#define E7XXX_DRA               0x70    /* DRAM row attribute register (8b) */
                                        /*
                                         * 31   Device width row 7 0=x8 1=x4
                                         * 27   Device width row 6
                                         * 23   Device width row 5
                                         * 19   Device width row 4
                                         * 15   Device width row 3
                                         * 11   Device width row 2
                                         *  7   Device width row 1
                                         *  3   Device width row 0
                                         */
#define E7XXX_DRC               0x7C    /* DRAM controller mode reg (32b) */
                                        /*
                                         * 22    Number channels 0=1,1=2
                                         * 19:18 DRB Granularity 32/64MB
                                         */
#define E7XXX_TOLM              0xC4    /* DRAM top of low memory reg (16b) */
#define E7XXX_REMAPBASE         0xC6    /* DRAM remap base address reg (16b) */
#define E7XXX_REMAPLIMIT        0xC8    /* DRAM remap limit address reg (16b) */

/* E7XXX register addresses - device 0 function 1 */
#define E7XXX_DRAM_FERR         0x80    /* DRAM first error register (8b) */
#define E7XXX_DRAM_NERR         0x82    /* DRAM next error register (8b) */
#define E7XXX_DRAM_CELOG_ADD    0xA0    /* DRAM first correctable memory */
                                        /*     error address register (32b) */
                                        /*
                                         * 31:28 Reserved
                                         * 27:6  CE address (4k block 33:12)
                                         *  5:0  Reserved
                                         */
#define E7XXX_DRAM_UELOG_ADD    0xB0    /* DRAM first uncorrectable memory */
                                        /*     error address register (32b) */
                                        /*
                                         * 31:28 Reserved
                                         * 27:6  CE address (4k block 33:12)
                                         *  5:0  Reserved
                                         */
#define E7XXX_DRAM_CELOG_SYNDROME 0xD0  /* DRAM first correctable memory */
                                        /*     error syndrome register (16b) */

enum e7xxx_chips {
        E7500 = 0,
        E7501,
        E7505,
        E7205,
};

struct e7xxx_pvt {
        struct pci_dev *bridge_ck;
        u32 tolm;
        u32 remapbase;
        u32 remaplimit;
        const struct e7xxx_dev_info *dev_info;
};

struct e7xxx_dev_info {
        u16 err_dev;
        const char *ctl_name;
};

struct e7xxx_error_info {
        u8 dram_ferr;
        u8 dram_nerr;
        u32 dram_celog_add;
        u16 dram_celog_syndrome;
        u32 dram_uelog_add;
};

static struct edac_pci_ctl_info *e7xxx_pci;

static const struct e7xxx_dev_info e7xxx_devs[] = {
        [E7500] = {
                .err_dev = PCI_DEVICE_ID_INTEL_7500_1_ERR,
                .ctl_name = "E7500"},
        [E7501] = {
                .err_dev = PCI_DEVICE_ID_INTEL_7501_1_ERR,
                .ctl_name = "E7501"},
        [E7505] = {
                .err_dev = PCI_DEVICE_ID_INTEL_7505_1_ERR,
                .ctl_name = "E7505"},
        [E7205] = {
                .err_dev = PCI_DEVICE_ID_INTEL_7205_1_ERR,
                .ctl_name = "E7205"},
};

/* FIXME - is this valid for both SECDED and S4ECD4ED? */
static inline int e7xxx_find_channel(u16 syndrome)
{
        edac_dbg(3, "\n");

        if ((syndrome & 0xff00) == 0)
                return 0;

        if ((syndrome & 0x00ff) == 0)
                return 1;

        if ((syndrome & 0xf000) == 0 || (syndrome & 0x0f00) == 0)
                return 0;

        return 1;
}

static unsigned long ctl_page_to_phys(struct mem_ctl_info *mci,
                                unsigned long page)
{
        u32 remap;
        struct e7xxx_pvt *pvt = (struct e7xxx_pvt *)mci->pvt_info;

        edac_dbg(3, "\n");

        if ((page < pvt->tolm) ||
                ((page >= 0x100000) && (page < pvt->remapbase)))
                return page;

        remap = (page - pvt->tolm) + pvt->remapbase;

        if (remap < pvt->remaplimit)
                return remap;

        e7xxx_printk(KERN_ERR, "Invalid page %lx - out of range\n", page);
        return pvt->tolm - 1;
}

static void process_ce(struct mem_ctl_info *mci, struct e7xxx_error_info *info)
{
        u32 error_1b, page;
        u16 syndrome;
        int row;
        int channel;

        edac_dbg(3, "\n");
        /* read the error address */
        error_1b = info->dram_celog_add;
        /* FIXME - should use PAGE_SHIFT */
        page = error_1b >> 6;   /* convert the address to 4k page */
        /* read the syndrome */
        syndrome = info->dram_celog_syndrome;
        /* FIXME - check for -1 */
        row = edac_mc_find_csrow_by_page(mci, page);
        /* convert syndrome to channel */
        channel = e7xxx_find_channel(syndrome);
        edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1, page, 0, syndrome,
                             row, channel, -1, "e7xxx CE", "");
}

static void process_ce_no_info(struct mem_ctl_info *mci)
{
        edac_dbg(3, "\n");
        edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1, 0, 0, 0, -1, -1, -1,
                             "e7xxx CE log register overflow", "");
}

static void process_ue(struct mem_ctl_info *mci, struct e7xxx_error_info *info)
{
        u32 error_2b, block_page;
        int row;

        edac_dbg(3, "\n");
        /* read the error address */
        error_2b = info->dram_uelog_add;
        /* FIXME - should use PAGE_SHIFT */
        block_page = error_2b >> 6;     /* convert to 4k address */
        row = edac_mc_find_csrow_by_page(mci, block_page);

        edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1, block_page, 0, 0,
                             row, -1, -1, "e7xxx UE", "");
}

static void process_ue_no_info(struct mem_ctl_info *mci)
{
        edac_dbg(3, "\n");

        edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1, 0, 0, 0, -1, -1, -1,
                             "e7xxx UE log register overflow", "");
}

static void e7xxx_get_error_info(struct mem_ctl_info *mci,
                                 struct e7xxx_error_info *info)
{
        struct e7xxx_pvt *pvt;

        pvt = (struct e7xxx_pvt *)mci->pvt_info;
        pci_read_config_byte(pvt->bridge_ck, E7XXX_DRAM_FERR, &info->dram_ferr);
        pci_read_config_byte(pvt->bridge_ck, E7XXX_DRAM_NERR, &info->dram_nerr);

        if ((info->dram_ferr & 1) || (info->dram_nerr & 1)) {
                pci_read_config_dword(pvt->bridge_ck, E7XXX_DRAM_CELOG_ADD,
                                &info->dram_celog_add);
                pci_read_config_word(pvt->bridge_ck,
                                E7XXX_DRAM_CELOG_SYNDROME,
                                &info->dram_celog_syndrome);
        }

        if ((info->dram_ferr & 2) || (info->dram_nerr & 2))
                pci_read_config_dword(pvt->bridge_ck, E7XXX_DRAM_UELOG_ADD,
                                &info->dram_uelog_add);

        if (info->dram_ferr & 3)
                pci_write_bits8(pvt->bridge_ck, E7XXX_DRAM_FERR, 0x03, 0x03);

        if (info->dram_nerr & 3)
                pci_write_bits8(pvt->bridge_ck, E7XXX_DRAM_NERR, 0x03, 0x03);
}

static int e7xxx_process_error_info(struct mem_ctl_info *mci,
                                struct e7xxx_error_info *info,
                                int handle_errors)
{
        int error_found;

        error_found = 0;

        /* decode and report errors */
        if (info->dram_ferr & 1) {      /* check first error correctable */
                error_found = 1;

                if (handle_errors)
                        process_ce(mci, info);
        }

        if (info->dram_ferr & 2) {      /* check first error uncorrectable */
                error_found = 1;

                if (handle_errors)
                        process_ue(mci, info);
        }

        if (info->dram_nerr & 1) {      /* check next error correctable */
                error_found = 1;

                if (handle_errors) {
                        if (info->dram_ferr & 1)
                                process_ce_no_info(mci);
                        else
                                process_ce(mci, info);
                }
        }

        if (info->dram_nerr & 2) {      /* check next error uncorrectable */
                error_found = 1;

                if (handle_errors) {
                        if (info->dram_ferr & 2)
                                process_ue_no_info(mci);
                        else
                                process_ue(mci, info);
                }
        }

        return error_found;
}

static void e7xxx_check(struct mem_ctl_info *mci)
{
        struct e7xxx_error_info info;

        e7xxx_get_error_info(mci, &info);
        e7xxx_process_error_info(mci, &info, 1);
}

/* Return 1 if dual channel mode is active.  Else return 0. */
static inline int dual_channel_active(u32 drc, int dev_idx)
{
        return (dev_idx == E7501) ? ((drc >> 22) & 0x1) : 1;
}

/* Return DRB granularity (0=32mb, 1=64mb). */
static inline int drb_granularity(u32 drc, int dev_idx)
{
        /* only e7501 can be single channel */
        return (dev_idx == E7501) ? ((drc >> 18) & 0x3) : 1;
}

static void e7xxx_init_csrows(struct mem_ctl_info *mci, struct pci_dev *pdev,
                        int dev_idx, u32 drc)
{
        unsigned long last_cumul_size;
        int index, j;
        u8 value;
        u32 dra, cumul_size, nr_pages;
        int drc_chan, drc_drbg, drc_ddim, mem_dev;
        struct csrow_info *csrow;
        struct dimm_info *dimm;
        enum edac_type edac_mode;

        pci_read_config_dword(pdev, E7XXX_DRA, &dra);
        drc_chan = dual_channel_active(drc, dev_idx);
        drc_drbg = drb_granularity(drc, dev_idx);
        drc_ddim = (drc >> 20) & 0x3;
        last_cumul_size = 0;

        /* The dram row boundary (DRB) reg values are boundary address
         * for each DRAM row with a granularity of 32 or 64MB (single/dual
         * channel operation).  DRB regs are cumulative; therefore DRB7 will
         * contain the total memory contained in all eight rows.
         */
        for (index = 0; index < mci->nr_csrows; index++) {
                /* mem_dev 0=x8, 1=x4 */
                mem_dev = (dra >> (index * 4 + 3)) & 0x1;
                csrow = mci->csrows[index];

                pci_read_config_byte(pdev, E7XXX_DRB + index, &value);
                /* convert a 64 or 32 MiB DRB to a page size. */
                cumul_size = value << (25 + drc_drbg - PAGE_SHIFT);
                edac_dbg(3, "(%d) cumul_size 0x%x\n", index, cumul_size);
                if (cumul_size == last_cumul_size)
                        continue;       /* not populated */

                csrow->first_page = last_cumul_size;
                csrow->last_page = cumul_size - 1;
                nr_pages = cumul_size - last_cumul_size;
                last_cumul_size = cumul_size;

                /*
                * if single channel or x8 devices then SECDED
                * if dual channel and x4 then S4ECD4ED
                */
                if (drc_ddim) {
                        if (drc_chan && mem_dev) {
                                edac_mode = EDAC_S4ECD4ED;
                                mci->edac_cap |= EDAC_FLAG_S4ECD4ED;
                        } else {
                                edac_mode = EDAC_SECDED;
                                mci->edac_cap |= EDAC_FLAG_SECDED;
                        }
                } else
                        edac_mode = EDAC_NONE;

                for (j = 0; j < drc_chan + 1; j++) {
                        dimm = csrow->channels[j]->dimm;

                        dimm->nr_pages = nr_pages / (drc_chan + 1);
                        dimm->grain = 1 << 12;  /* 4KiB - resolution of CELOG */
                        dimm->mtype = MEM_RDDR; /* only one type supported */
                        dimm->dtype = mem_dev ? DEV_X4 : DEV_X8;
                        dimm->edac_mode = edac_mode;
                }
        }
}

static int e7xxx_probe1(struct pci_dev *pdev, int dev_idx)
{
        u16 pci_data;
        struct mem_ctl_info *mci = NULL;
        struct edac_mc_layer layers[2];
        struct e7xxx_pvt *pvt = NULL;
        u32 drc;
        int drc_chan;
        struct e7xxx_error_info discard;

        edac_dbg(0, "mci\n");

        pci_read_config_dword(pdev, E7XXX_DRC, &drc);

        drc_chan = dual_channel_active(drc, dev_idx);
        /*
         * According with the datasheet, this device has a maximum of
         * 4 DIMMS per channel, either single-rank or dual-rank. So, the
         * total amount of dimms is 8 (E7XXX_NR_DIMMS).
         * That means that the DIMM is mapped as CSROWs, and the channel
         * will map the rank. So, an error to either channel should be
         * attributed to the same dimm.
         */
        layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
        layers[0].size = E7XXX_NR_CSROWS;
        layers[0].is_virt_csrow = true;
        layers[1].type = EDAC_MC_LAYER_CHANNEL;
        layers[1].size = drc_chan + 1;
        layers[1].is_virt_csrow = false;
        mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, sizeof(*pvt));
        if (mci == NULL)
                return -ENOMEM;

        edac_dbg(3, "init mci\n");
        mci->mtype_cap = MEM_FLAG_RDDR;
        mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED |
                EDAC_FLAG_S4ECD4ED;
        /* FIXME - what if different memory types are in different csrows? */
        mci->mod_name = EDAC_MOD_STR;
        mci->pdev = &pdev->dev;
        edac_dbg(3, "init pvt\n");
        pvt = (struct e7xxx_pvt *)mci->pvt_info;
        pvt->dev_info = &e7xxx_devs[dev_idx];
        pvt->bridge_ck = pci_get_device(PCI_VENDOR_ID_INTEL,
                                        pvt->dev_info->err_dev, pvt->bridge_ck);

        if (!pvt->bridge_ck) {
                e7xxx_printk(KERN_ERR, "error reporting device not found:"
                        "vendor %x device 0x%x (broken BIOS?)\n",
                        PCI_VENDOR_ID_INTEL, e7xxx_devs[dev_idx].err_dev);
                goto fail0;
        }

        edac_dbg(3, "more mci init\n");
        mci->ctl_name = pvt->dev_info->ctl_name;
        mci->dev_name = pci_name(pdev);
        mci->edac_check = e7xxx_check;
        mci->ctl_page_to_phys = ctl_page_to_phys;
        e7xxx_init_csrows(mci, pdev, dev_idx, drc);
        mci->edac_cap |= EDAC_FLAG_NONE;
        edac_dbg(3, "tolm, remapbase, remaplimit\n");
        /* load the top of low memory, remap base, and remap limit vars */
        pci_read_config_word(pdev, E7XXX_TOLM, &pci_data);
        pvt->tolm = ((u32) pci_data) << 4;
        pci_read_config_word(pdev, E7XXX_REMAPBASE, &pci_data);
        pvt->remapbase = ((u32) pci_data) << 14;
        pci_read_config_word(pdev, E7XXX_REMAPLIMIT, &pci_data);
        pvt->remaplimit = ((u32) pci_data) << 14;
        e7xxx_printk(KERN_INFO,
                "tolm = %x, remapbase = %x, remaplimit = %x\n", pvt->tolm,
                pvt->remapbase, pvt->remaplimit);

        /* clear any pending errors, or initial state bits */
        e7xxx_get_error_info(mci, &discard);

        /* Here we assume that we will never see multiple instances of this
         * type of memory controller.  The ID is therefore hardcoded to 0.
         */
        if (edac_mc_add_mc(mci)) {
                edac_dbg(3, "failed edac_mc_add_mc()\n");
                goto fail1;
        }

        /* allocating generic PCI control info */
        e7xxx_pci = edac_pci_create_generic_ctl(&pdev->dev, EDAC_MOD_STR);
        if (!e7xxx_pci) {
                printk(KERN_WARNING
                        "%s(): Unable to create PCI control\n",
                        __func__);
                printk(KERN_WARNING
                        "%s(): PCI error report via EDAC not setup\n",
                        __func__);
        }

        /* get this far and it's successful */
        edac_dbg(3, "success\n");
        return 0;

fail1:
        pci_dev_put(pvt->bridge_ck);

fail0:
        edac_mc_free(mci);

        return -ENODEV;
}

/* returns count (>= 0), or negative on error */
static int e7xxx_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        edac_dbg(0, "\n");

        /* wake up and enable device */
        return pci_enable_device(pdev) ?
                -EIO : e7xxx_probe1(pdev, ent->driver_data);
}

static void e7xxx_remove_one(struct pci_dev *pdev)
{
        struct mem_ctl_info *mci;
        struct e7xxx_pvt *pvt;

        edac_dbg(0, "\n");

        if (e7xxx_pci)
                edac_pci_release_generic_ctl(e7xxx_pci);

        if ((mci = edac_mc_del_mc(&pdev->dev)) == NULL)
                return;

        pvt = (struct e7xxx_pvt *)mci->pvt_info;
        pci_dev_put(pvt->bridge_ck);
        edac_mc_free(mci);
}

static const struct pci_device_id e7xxx_pci_tbl[] = {
        {
         PCI_VEND_DEV(INTEL, 7205_0), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
         E7205},
        {
         PCI_VEND_DEV(INTEL, 7500_0), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
         E7500},
        {
         PCI_VEND_DEV(INTEL, 7501_0), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
         E7501},
        {
         PCI_VEND_DEV(INTEL, 7505_0), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
         E7505},
        {
         0,
         }                      /* 0 terminated list. */
};

MODULE_DEVICE_TABLE(pci, e7xxx_pci_tbl);

static struct pci_driver e7xxx_driver = {
        .name = EDAC_MOD_STR,
        .probe = e7xxx_init_one,
        .remove = e7xxx_remove_one,
        .id_table = e7xxx_pci_tbl,
};

static int __init e7xxx_init(void)
{
       /* Ensure that the OPSTATE is set correctly for POLL or NMI */
       opstate_init();

        return pci_register_driver(&e7xxx_driver);
}

static void __exit e7xxx_exit(void)
{
        pci_unregister_driver(&e7xxx_driver);
}

module_init(e7xxx_init);
module_exit(e7xxx_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Linux Networx (http://lnxi.com) Thayne Harbaugh et al");
MODULE_DESCRIPTION("MC support for Intel e7xxx memory controllers");
module_param(edac_op_state, int, 0444);
MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting state: 0=Poll,1=NMI");