/*
 * Intel 5100 Memory Controllers kernel module
 *
 * This file may be distributed under the terms of the
 * GNU General Public License.
 *
 * This module is based on the following document:
 *
 * Intel 5100X Chipset Memory Controller Hub (MCH) - Datasheet
 *      http://download.intel.com/design/chipsets/datashts/318378.pdf
 *
 * The intel 5100 has two independent channels. EDAC core currently
 * can not reflect this configuration so instead the chip-select
 * rows for each respective channel are laid out one after another,
 * the first half belonging to channel 0, the second half belonging
 * to channel 1.
 *
 * This driver is for DDR2 DIMMs, and it uses chip select to select among the
 * several ranks. However, instead of showing memories as ranks, it outputs
 * them as DIMM's. An internal table creates the association between ranks
 * and DIMM's.
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/edac.h>
#include <linux/delay.h>
#include <linux/mmzone.h>
#include <linux/debugfs.h>

#include "edac_module.h"

/* register addresses */

/* device 16, func 1 */
#define I5100_MC                0x40    /* Memory Control Register */
#define         I5100_MC_SCRBEN_MASK    (1 << 7)
#define         I5100_MC_SCRBDONE_MASK  (1 << 4)
#define I5100_MS                0x44    /* Memory Status Register */
#define I5100_SPDDATA           0x48    /* Serial Presence Detect Status Reg */
#define I5100_SPDCMD            0x4c    /* Serial Presence Detect Command Reg */
#define I5100_TOLM              0x6c    /* Top of Low Memory */
#define I5100_MIR0              0x80    /* Memory Interleave Range 0 */
#define I5100_MIR1              0x84    /* Memory Interleave Range 1 */
#define I5100_AMIR_0            0x8c    /* Adjusted Memory Interleave Range 0 */
#define I5100_AMIR_1            0x90    /* Adjusted Memory Interleave Range 1 */
#define I5100_FERR_NF_MEM       0xa0    /* MC First Non Fatal Errors */
#define         I5100_FERR_NF_MEM_M16ERR_MASK   (1 << 16)
#define         I5100_FERR_NF_MEM_M15ERR_MASK   (1 << 15)
#define         I5100_FERR_NF_MEM_M14ERR_MASK   (1 << 14)
#define         I5100_FERR_NF_MEM_M12ERR_MASK   (1 << 12)
#define         I5100_FERR_NF_MEM_M11ERR_MASK   (1 << 11)
#define         I5100_FERR_NF_MEM_M10ERR_MASK   (1 << 10)
#define         I5100_FERR_NF_MEM_M6ERR_MASK    (1 << 6)
#define         I5100_FERR_NF_MEM_M5ERR_MASK    (1 << 5)
#define         I5100_FERR_NF_MEM_M4ERR_MASK    (1 << 4)
#define         I5100_FERR_NF_MEM_M1ERR_MASK    (1 << 1)
#define         I5100_FERR_NF_MEM_ANY_MASK      \
                        (I5100_FERR_NF_MEM_M16ERR_MASK | \
                        I5100_FERR_NF_MEM_M15ERR_MASK | \
                        I5100_FERR_NF_MEM_M14ERR_MASK | \
                        I5100_FERR_NF_MEM_M12ERR_MASK | \
                        I5100_FERR_NF_MEM_M11ERR_MASK | \
                        I5100_FERR_NF_MEM_M10ERR_MASK | \
                        I5100_FERR_NF_MEM_M6ERR_MASK | \
                        I5100_FERR_NF_MEM_M5ERR_MASK | \
                        I5100_FERR_NF_MEM_M4ERR_MASK | \
                        I5100_FERR_NF_MEM_M1ERR_MASK)
#define I5100_NERR_NF_MEM       0xa4    /* MC Next Non-Fatal Errors */
#define I5100_EMASK_MEM         0xa8    /* MC Error Mask Register */
#define I5100_MEM0EINJMSK0      0x200   /* Injection Mask0 Register Channel 0 */
#define I5100_MEM1EINJMSK0      0x208   /* Injection Mask0 Register Channel 1 */
#define         I5100_MEMXEINJMSK0_EINJEN       (1 << 27)
#define I5100_MEM0EINJMSK1      0x204   /* Injection Mask1 Register Channel 0 */
#define I5100_MEM1EINJMSK1      0x206   /* Injection Mask1 Register Channel 1 */

/* Device 19, Function 0 */
#define I5100_DINJ0 0x9a

/* device 21 and 22, func 0 */
#define I5100_MTR_0     0x154   /* Memory Technology Registers 0-3 */
#define I5100_DMIR      0x15c   /* DIMM Interleave Range */
#define I5100_VALIDLOG  0x18c   /* Valid Log Markers */
#define I5100_NRECMEMA  0x190   /* Non-Recoverable Memory Error Log Reg A */
#define I5100_NRECMEMB  0x194   /* Non-Recoverable Memory Error Log Reg B */
#define I5100_REDMEMA   0x198   /* Recoverable Memory Data Error Log Reg A */
#define I5100_REDMEMB   0x19c   /* Recoverable Memory Data Error Log Reg B */
#define I5100_RECMEMA   0x1a0   /* Recoverable Memory Error Log Reg A */
#define I5100_RECMEMB   0x1a4   /* Recoverable Memory Error Log Reg B */
#define I5100_MTR_4     0x1b0   /* Memory Technology Registers 4,5 */

/* bit field accessors */

static inline u32 i5100_mc_scrben(u32 mc)
{
        return mc >> 7 & 1;
}

static inline u32 i5100_mc_errdeten(u32 mc)
{
        return mc >> 5 & 1;
}

static inline u32 i5100_mc_scrbdone(u32 mc)
{
        return mc >> 4 & 1;
}

static inline u16 i5100_spddata_rdo(u16 a)
{
        return a >> 15 & 1;
}

static inline u16 i5100_spddata_sbe(u16 a)
{
        return a >> 13 & 1;
}

static inline u16 i5100_spddata_busy(u16 a)
{
        return a >> 12 & 1;
}

static inline u16 i5100_spddata_data(u16 a)
{
        return a & ((1 << 8) - 1);
}

static inline u32 i5100_spdcmd_create(u32 dti, u32 ckovrd, u32 sa, u32 ba,
                                      u32 data, u32 cmd)
{
        return  ((dti & ((1 << 4) - 1))  << 28) |
                ((ckovrd & 1)            << 27) |
                ((sa & ((1 << 3) - 1))   << 24) |
                ((ba & ((1 << 8) - 1))   << 16) |
                ((data & ((1 << 8) - 1)) <<  8) |
                (cmd & 1);
}

static inline u16 i5100_tolm_tolm(u16 a)
{
        return a >> 12 & ((1 << 4) - 1);
}

static inline u16 i5100_mir_limit(u16 a)
{
        return a >> 4 & ((1 << 12) - 1);
}

static inline u16 i5100_mir_way1(u16 a)
{
        return a >> 1 & 1;
}

static inline u16 i5100_mir_way0(u16 a)
{
        return a & 1;
}

static inline u32 i5100_ferr_nf_mem_chan_indx(u32 a)
{
        return a >> 28 & 1;
}

static inline u32 i5100_ferr_nf_mem_any(u32 a)
{
        return a & I5100_FERR_NF_MEM_ANY_MASK;
}

static inline u32 i5100_nerr_nf_mem_any(u32 a)
{
        return i5100_ferr_nf_mem_any(a);
}

static inline u32 i5100_dmir_limit(u32 a)
{
        return a >> 16 & ((1 << 11) - 1);
}

static inline u32 i5100_dmir_rank(u32 a, u32 i)
{
        return a >> (4 * i) & ((1 << 2) - 1);
}

static inline u16 i5100_mtr_present(u16 a)
{
        return a >> 10 & 1;
}

static inline u16 i5100_mtr_ethrottle(u16 a)
{
        return a >> 9 & 1;
}

static inline u16 i5100_mtr_width(u16 a)
{
        return a >> 8 & 1;
}

static inline u16 i5100_mtr_numbank(u16 a)
{
        return a >> 6 & 1;
}

static inline u16 i5100_mtr_numrow(u16 a)
{
        return a >> 2 & ((1 << 2) - 1);
}

static inline u16 i5100_mtr_numcol(u16 a)
{
        return a & ((1 << 2) - 1);
}


static inline u32 i5100_validlog_redmemvalid(u32 a)
{
        return a >> 2 & 1;
}

static inline u32 i5100_validlog_recmemvalid(u32 a)
{
        return a >> 1 & 1;
}

static inline u32 i5100_validlog_nrecmemvalid(u32 a)
{
        return a & 1;
}

static inline u32 i5100_nrecmema_merr(u32 a)
{
        return a >> 15 & ((1 << 5) - 1);
}

static inline u32 i5100_nrecmema_bank(u32 a)
{
        return a >> 12 & ((1 << 3) - 1);
}

static inline u32 i5100_nrecmema_rank(u32 a)
{
        return a >>  8 & ((1 << 3) - 1);
}

static inline u32 i5100_nrecmemb_cas(u32 a)
{
        return a >> 16 & ((1 << 13) - 1);
}

static inline u32 i5100_nrecmemb_ras(u32 a)
{
        return a & ((1 << 16) - 1);
}

static inline u32 i5100_recmema_merr(u32 a)
{
        return i5100_nrecmema_merr(a);
}

static inline u32 i5100_recmema_bank(u32 a)
{
        return i5100_nrecmema_bank(a);
}

static inline u32 i5100_recmema_rank(u32 a)
{
        return i5100_nrecmema_rank(a);
}

static inline u32 i5100_recmemb_cas(u32 a)
{
        return i5100_nrecmemb_cas(a);
}

static inline u32 i5100_recmemb_ras(u32 a)
{
        return i5100_nrecmemb_ras(a);
}

/* some generic limits */
#define I5100_MAX_RANKS_PER_CHAN        6
#define I5100_CHANNELS                      2
#define I5100_MAX_RANKS_PER_DIMM        4
#define I5100_DIMM_ADDR_LINES           (6 - 3) /* 64 bits / 8 bits per byte */
#define I5100_MAX_DIMM_SLOTS_PER_CHAN   4
#define I5100_MAX_RANK_INTERLEAVE       4
#define I5100_MAX_DMIRS                 5
#define I5100_SCRUB_REFRESH_RATE        (5 * 60 * HZ)

struct i5100_priv {
        /* ranks on each dimm -- 0 maps to not present -- obtained via SPD */
        int dimm_numrank[I5100_CHANNELS][I5100_MAX_DIMM_SLOTS_PER_CHAN];

        /*
         * mainboard chip select map -- maps i5100 chip selects to
         * DIMM slot chip selects.  In the case of only 4 ranks per
         * channel, the mapping is fairly obvious but not unique.
         * we map -1 -> NC and assume both channels use the same
         * map...
         *
         */
        int dimm_csmap[I5100_MAX_DIMM_SLOTS_PER_CHAN][I5100_MAX_RANKS_PER_DIMM];

        /* memory interleave range */
        struct {
                u64      limit;
                unsigned way[2];
        } mir[I5100_CHANNELS];

        /* adjusted memory interleave range register */
        unsigned amir[I5100_CHANNELS];

        /* dimm interleave range */
        struct {
                unsigned rank[I5100_MAX_RANK_INTERLEAVE];
                u64      limit;
        } dmir[I5100_CHANNELS][I5100_MAX_DMIRS];

        /* memory technology registers... */
        struct {
                unsigned present;       /* 0 or 1 */
                unsigned ethrottle;     /* 0 or 1 */
                unsigned width;         /* 4 or 8 bits  */
                unsigned numbank;       /* 2 or 3 lines */
                unsigned numrow;        /* 13 .. 16 lines */
                unsigned numcol;        /* 11 .. 12 lines */
        } mtr[I5100_CHANNELS][I5100_MAX_RANKS_PER_CHAN];

        u64 tolm;               /* top of low memory in bytes */
        unsigned ranksperchan;  /* number of ranks per channel */

        struct pci_dev *mc;     /* device 16 func 1 */
        struct pci_dev *einj;   /* device 19 func 0 */
        struct pci_dev *ch0mm;  /* device 21 func 0 */
        struct pci_dev *ch1mm;  /* device 22 func 0 */

        struct delayed_work i5100_scrubbing;
        int scrub_enable;

        /* Error injection */
        u8 inject_channel;
        u8 inject_hlinesel;
        u8 inject_deviceptr1;
        u8 inject_deviceptr2;
        u16 inject_eccmask1;
        u16 inject_eccmask2;

        struct dentry *debugfs;
};

static struct dentry *i5100_debugfs;

/* map a rank/chan to a slot number on the mainboard */
static int i5100_rank_to_slot(const struct mem_ctl_info *mci,
                              int chan, int rank)
{
        const struct i5100_priv *priv = mci->pvt_info;
        int i;

        for (i = 0; i < I5100_MAX_DIMM_SLOTS_PER_CHAN; i++) {
                int j;
                const int numrank = priv->dimm_numrank[chan][i];

                for (j = 0; j < numrank; j++)
                        if (priv->dimm_csmap[i][j] == rank)
                                return i * 2 + chan;
        }

        return -1;
}

static const char *i5100_err_msg(unsigned err)
{
        static const char *merrs[] = {
                "unknown", /* 0 */
                "uncorrectable data ECC on replay", /* 1 */
                "unknown", /* 2 */
                "unknown", /* 3 */
                "aliased uncorrectable demand data ECC", /* 4 */
                "aliased uncorrectable spare-copy data ECC", /* 5 */
                "aliased uncorrectable patrol data ECC", /* 6 */
                "unknown", /* 7 */
                "unknown", /* 8 */
                "unknown", /* 9 */
                "non-aliased uncorrectable demand data ECC", /* 10 */
                "non-aliased uncorrectable spare-copy data ECC", /* 11 */
                "non-aliased uncorrectable patrol data ECC", /* 12 */
                "unknown", /* 13 */
                "correctable demand data ECC", /* 14 */
                "correctable spare-copy data ECC", /* 15 */
                "correctable patrol data ECC", /* 16 */
                "unknown", /* 17 */
                "SPD protocol error", /* 18 */
                "unknown", /* 19 */
                "spare copy initiated", /* 20 */
                "spare copy completed", /* 21 */
        };
        unsigned i;

        for (i = 0; i < ARRAY_SIZE(merrs); i++)
                if (1 << i & err)
                        return merrs[i];

        return "none";
}

/* convert csrow index into a rank (per channel -- 0..5) */
static unsigned int i5100_csrow_to_rank(const struct mem_ctl_info *mci,
                                        unsigned int csrow)
{
        const struct i5100_priv *priv = mci->pvt_info;

        return csrow % priv->ranksperchan;
}

/* convert csrow index into a channel (0..1) */
static unsigned int i5100_csrow_to_chan(const struct mem_ctl_info *mci,
                                        unsigned int csrow)
{
        const struct i5100_priv *priv = mci->pvt_info;

        return csrow / priv->ranksperchan;
}

static void i5100_handle_ce(struct mem_ctl_info *mci,
                            int chan,
                            unsigned bank,
                            unsigned rank,
                            unsigned long syndrome,
                            unsigned cas,
                            unsigned ras,
                            const char *msg)
{
        char detail[80];

        /* Form out message */
        snprintf(detail, sizeof(detail),
                 "bank %u, cas %u, ras %u\n",
                 bank, cas, ras);

        edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
                             0, 0, syndrome,
                             chan, rank, -1,
                             msg, detail);
}

static void i5100_handle_ue(struct mem_ctl_info *mci,
                            int chan,
                            unsigned bank,
                            unsigned rank,
                            unsigned long syndrome,
                            unsigned cas,
                            unsigned ras,
                            const char *msg)
{
        char detail[80];

        /* Form out message */
        snprintf(detail, sizeof(detail),
                 "bank %u, cas %u, ras %u\n",
                 bank, cas, ras);

        edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
                             0, 0, syndrome,
                             chan, rank, -1,
                             msg, detail);
}

static void i5100_read_log(struct mem_ctl_info *mci, int chan,
                           u32 ferr, u32 nerr)
{
        struct i5100_priv *priv = mci->pvt_info;
        struct pci_dev *pdev = (chan) ? priv->ch1mm : priv->ch0mm;
        u32 dw;
        u32 dw2;
        unsigned syndrome = 0;
        unsigned merr;
        unsigned bank;
        unsigned rank;
        unsigned cas;
        unsigned ras;

        pci_read_config_dword(pdev, I5100_VALIDLOG, &dw);

        if (i5100_validlog_redmemvalid(dw)) {
                pci_read_config_dword(pdev, I5100_REDMEMA, &dw2);
                syndrome = dw2;
                pci_read_config_dword(pdev, I5100_REDMEMB, &dw2);
        }

        if (i5100_validlog_recmemvalid(dw)) {
                const char *msg;

                pci_read_config_dword(pdev, I5100_RECMEMA, &dw2);
                merr = i5100_recmema_merr(dw2);
                bank = i5100_recmema_bank(dw2);
                rank = i5100_recmema_rank(dw2);

                pci_read_config_dword(pdev, I5100_RECMEMB, &dw2);
                cas = i5100_recmemb_cas(dw2);
                ras = i5100_recmemb_ras(dw2);

                /* FIXME:  not really sure if this is what merr is...
                 */
                if (!merr)
                        msg = i5100_err_msg(ferr);
                else
                        msg = i5100_err_msg(nerr);

                i5100_handle_ce(mci, chan, bank, rank, syndrome, cas, ras, msg);
        }

        if (i5100_validlog_nrecmemvalid(dw)) {
                const char *msg;

                pci_read_config_dword(pdev, I5100_NRECMEMA, &dw2);
                merr = i5100_nrecmema_merr(dw2);
                bank = i5100_nrecmema_bank(dw2);
                rank = i5100_nrecmema_rank(dw2);

                pci_read_config_dword(pdev, I5100_NRECMEMB, &dw2);
                cas = i5100_nrecmemb_cas(dw2);
                ras = i5100_nrecmemb_ras(dw2);

                /* FIXME:  not really sure if this is what merr is...
                 */
                if (!merr)
                        msg = i5100_err_msg(ferr);
                else
                        msg = i5100_err_msg(nerr);

                i5100_handle_ue(mci, chan, bank, rank, syndrome, cas, ras, msg);
        }

        pci_write_config_dword(pdev, I5100_VALIDLOG, dw);
}

static void i5100_check_error(struct mem_ctl_info *mci)
{
        struct i5100_priv *priv = mci->pvt_info;
        u32 dw, dw2;

        pci_read_config_dword(priv->mc, I5100_FERR_NF_MEM, &dw);
        if (i5100_ferr_nf_mem_any(dw)) {

                pci_read_config_dword(priv->mc, I5100_NERR_NF_MEM, &dw2);

                i5100_read_log(mci, i5100_ferr_nf_mem_chan_indx(dw),
                               i5100_ferr_nf_mem_any(dw),
                               i5100_nerr_nf_mem_any(dw2));

                pci_write_config_dword(priv->mc, I5100_NERR_NF_MEM, dw2);
        }
        pci_write_config_dword(priv->mc, I5100_FERR_NF_MEM, dw);
}

/* The i5100 chipset will scrub the entire memory once, then
 * set a done bit. Continuous scrubbing is achieved by enqueing
 * delayed work to a workqueue, checking every few minutes if
 * the scrubbing has completed and if so reinitiating it.
 */

static void i5100_refresh_scrubbing(struct work_struct *work)
{
        struct delayed_work *i5100_scrubbing = to_delayed_work(work);
        struct i5100_priv *priv = container_of(i5100_scrubbing,
                                               struct i5100_priv,
                                               i5100_scrubbing);
        u32 dw;

        pci_read_config_dword(priv->mc, I5100_MC, &dw);

        if (priv->scrub_enable) {

                pci_read_config_dword(priv->mc, I5100_MC, &dw);

                if (i5100_mc_scrbdone(dw)) {
                        dw |= I5100_MC_SCRBEN_MASK;
                        pci_write_config_dword(priv->mc, I5100_MC, dw);
                        pci_read_config_dword(priv->mc, I5100_MC, &dw);
                }

                schedule_delayed_work(&(priv->i5100_scrubbing),
                                      I5100_SCRUB_REFRESH_RATE);
        }
}
/*
 * The bandwidth is based on experimentation, feel free to refine it.
 */
static int i5100_set_scrub_rate(struct mem_ctl_info *mci, u32 bandwidth)
{
        struct i5100_priv *priv = mci->pvt_info;
        u32 dw;

        pci_read_config_dword(priv->mc, I5100_MC, &dw);
        if (bandwidth) {
                priv->scrub_enable = 1;
                dw |= I5100_MC_SCRBEN_MASK;
                schedule_delayed_work(&(priv->i5100_scrubbing),
                                      I5100_SCRUB_REFRESH_RATE);
        } else {
                priv->scrub_enable = 0;
                dw &= ~I5100_MC_SCRBEN_MASK;
                cancel_delayed_work(&(priv->i5100_scrubbing));
        }
        pci_write_config_dword(priv->mc, I5100_MC, dw);

        pci_read_config_dword(priv->mc, I5100_MC, &dw);

        bandwidth = 5900000 * i5100_mc_scrben(dw);

        return bandwidth;
}

static int i5100_get_scrub_rate(struct mem_ctl_info *mci)
{
        struct i5100_priv *priv = mci->pvt_info;
        u32 dw;

        pci_read_config_dword(priv->mc, I5100_MC, &dw);

        return 5900000 * i5100_mc_scrben(dw);
}

static struct pci_dev *pci_get_device_func(unsigned vendor,
                                           unsigned device,
                                           unsigned func)
{
        struct pci_dev *ret = NULL;

        while (1) {
                ret = pci_get_device(vendor, device, ret);

                if (!ret)
                        break;

                if (PCI_FUNC(ret->devfn) == func)
                        break;
        }

        return ret;
}

static unsigned long i5100_npages(struct mem_ctl_info *mci, unsigned int csrow)
{
        struct i5100_priv *priv = mci->pvt_info;
        const unsigned int chan_rank = i5100_csrow_to_rank(mci, csrow);
        const unsigned int chan = i5100_csrow_to_chan(mci, csrow);
        unsigned addr_lines;

        /* dimm present? */
        if (!priv->mtr[chan][chan_rank].present)
                return 0ULL;

        addr_lines =
                I5100_DIMM_ADDR_LINES +
                priv->mtr[chan][chan_rank].numcol +
                priv->mtr[chan][chan_rank].numrow +
                priv->mtr[chan][chan_rank].numbank;

        return (unsigned long)
                ((unsigned long long) (1ULL << addr_lines) / PAGE_SIZE);
}

static void i5100_init_mtr(struct mem_ctl_info *mci)
{
        struct i5100_priv *priv = mci->pvt_info;
        struct pci_dev *mms[2] = { priv->ch0mm, priv->ch1mm };
        int i;

        for (i = 0; i < I5100_CHANNELS; i++) {
                int j;
                struct pci_dev *pdev = mms[i];

                for (j = 0; j < I5100_MAX_RANKS_PER_CHAN; j++) {
                        const unsigned addr =
                                (j < 4) ? I5100_MTR_0 + j * 2 :
                                          I5100_MTR_4 + (j - 4) * 2;
                        u16 w;

                        pci_read_config_word(pdev, addr, &w);

                        priv->mtr[i][j].present = i5100_mtr_present(w);
                        priv->mtr[i][j].ethrottle = i5100_mtr_ethrottle(w);
                        priv->mtr[i][j].width = 4 + 4 * i5100_mtr_width(w);
                        priv->mtr[i][j].numbank = 2 + i5100_mtr_numbank(w);
                        priv->mtr[i][j].numrow = 13 + i5100_mtr_numrow(w);
                        priv->mtr[i][j].numcol = 10 + i5100_mtr_numcol(w);
                }
        }
}

/*
 * FIXME: make this into a real i2c adapter (so that dimm-decode
 * will work)?
 */
static int i5100_read_spd_byte(const struct mem_ctl_info *mci,
                               u8 ch, u8 slot, u8 addr, u8 *byte)
{
        struct i5100_priv *priv = mci->pvt_info;
        u16 w;

        pci_read_config_word(priv->mc, I5100_SPDDATA, &w);
        if (i5100_spddata_busy(w))
                return -1;

        pci_write_config_dword(priv->mc, I5100_SPDCMD,
                               i5100_spdcmd_create(0xa, 1, ch * 4 + slot, addr,
                                                   0, 0));

        /* wait up to 100ms */
        udelay(100);
        while (1) {
                pci_read_config_word(priv->mc, I5100_SPDDATA, &w);
                if (!i5100_spddata_busy(w))
                        break;
                udelay(100);
        }

        if (!i5100_spddata_rdo(w) || i5100_spddata_sbe(w))
                return -1;

        *byte = i5100_spddata_data(w);

        return 0;
}

/*
 * fill dimm chip select map
 *
 * FIXME:
 *   o not the only way to may chip selects to dimm slots
 *   o investigate if there is some way to obtain this map from the bios
 */
static void i5100_init_dimm_csmap(struct mem_ctl_info *mci)
{
        struct i5100_priv *priv = mci->pvt_info;
        int i;

        for (i = 0; i < I5100_MAX_DIMM_SLOTS_PER_CHAN; i++) {
                int j;

                for (j = 0; j < I5100_MAX_RANKS_PER_DIMM; j++)
                        priv->dimm_csmap[i][j] = -1; /* default NC */
        }

        /* only 2 chip selects per slot... */
        if (priv->ranksperchan == 4) {
                priv->dimm_csmap[0][0] = 0;
                priv->dimm_csmap[0][1] = 3;
                priv->dimm_csmap[1][0] = 1;
                priv->dimm_csmap[1][1] = 2;
                priv->dimm_csmap[2][0] = 2;
                priv->dimm_csmap[3][0] = 3;
        } else {
                priv->dimm_csmap[0][0] = 0;
                priv->dimm_csmap[0][1] = 1;
                priv->dimm_csmap[1][0] = 2;
                priv->dimm_csmap[1][1] = 3;
                priv->dimm_csmap[2][0] = 4;
                priv->dimm_csmap[2][1] = 5;
        }
}

static void i5100_init_dimm_layout(struct pci_dev *pdev,
                                   struct mem_ctl_info *mci)
{
        struct i5100_priv *priv = mci->pvt_info;
        int i;

        for (i = 0; i < I5100_CHANNELS; i++) {
                int j;

                for (j = 0; j < I5100_MAX_DIMM_SLOTS_PER_CHAN; j++) {
                        u8 rank;

                        if (i5100_read_spd_byte(mci, i, j, 5, &rank) < 0)
                                priv->dimm_numrank[i][j] = 0;
                        else
                                priv->dimm_numrank[i][j] = (rank & 3) + 1;
                }
        }

        i5100_init_dimm_csmap(mci);
}

static void i5100_init_interleaving(struct pci_dev *pdev,
                                    struct mem_ctl_info *mci)
{
        u16 w;
        u32 dw;
        struct i5100_priv *priv = mci->pvt_info;
        struct pci_dev *mms[2] = { priv->ch0mm, priv->ch1mm };
        int i;

        pci_read_config_word(pdev, I5100_TOLM, &w);
        priv->tolm = (u64) i5100_tolm_tolm(w) * 256 * 1024 * 1024;

        pci_read_config_word(pdev, I5100_MIR0, &w);
        priv->mir[0].limit = (u64) i5100_mir_limit(w) << 28;
        priv->mir[0].way[1] = i5100_mir_way1(w);
        priv->mir[0].way[0] = i5100_mir_way0(w);

        pci_read_config_word(pdev, I5100_MIR1, &w);
        priv->mir[1].limit = (u64) i5100_mir_limit(w) << 28;
        priv->mir[1].way[1] = i5100_mir_way1(w);
        priv->mir[1].way[0] = i5100_mir_way0(w);

        pci_read_config_word(pdev, I5100_AMIR_0, &w);
        priv->amir[0] = w;
        pci_read_config_word(pdev, I5100_AMIR_1, &w);
        priv->amir[1] = w;

        for (i = 0; i < I5100_CHANNELS; i++) {
                int j;

                for (j = 0; j < 5; j++) {
                        int k;

                        pci_read_config_dword(mms[i], I5100_DMIR + j * 4, &dw);

                        priv->dmir[i][j].limit =
                                (u64) i5100_dmir_limit(dw) << 28;
                        for (k = 0; k < I5100_MAX_RANKS_PER_DIMM; k++)
                                priv->dmir[i][j].rank[k] =
                                        i5100_dmir_rank(dw, k);
                }
        }

        i5100_init_mtr(mci);
}

static void i5100_init_csrows(struct mem_ctl_info *mci)
{
        struct i5100_priv *priv = mci->pvt_info;
        struct dimm_info *dimm;

        mci_for_each_dimm(mci, dimm) {
                const unsigned long npages = i5100_npages(mci, dimm->idx);
                const unsigned int chan = i5100_csrow_to_chan(mci, dimm->idx);
                const unsigned int rank = i5100_csrow_to_rank(mci, dimm->idx);

                if (!npages)
                        continue;

                dimm->nr_pages = npages;
                dimm->grain = 32;
                dimm->dtype = (priv->mtr[chan][rank].width == 4) ?
                                DEV_X4 : DEV_X8;
                dimm->mtype = MEM_RDDR2;
                dimm->edac_mode = EDAC_SECDED;
                snprintf(dimm->label, sizeof(dimm->label), "DIMM%u",
                         i5100_rank_to_slot(mci, chan, rank));

                edac_dbg(2, "dimm channel %d, rank %d, size %ld\n",
                         chan, rank, (long)PAGES_TO_MiB(npages));
        }
}

/****************************************************************************
 *                       Error injection routines
 ****************************************************************************/

static void i5100_do_inject(struct mem_ctl_info *mci)
{
        struct i5100_priv *priv = mci->pvt_info;
        u32 mask0;
        u16 mask1;

        /* MEM[1:0]EINJMSK0
         * 31    - ADDRMATCHEN
         * 29:28 - HLINESEL
         *         00 Reserved
         *         01 Lower half of cache line
         *         10 Upper half of cache line
         *         11 Both upper and lower parts of cache line
         * 27    - EINJEN
         * 25:19 - XORMASK1 for deviceptr1
         * 9:5   - SEC2RAM for deviceptr2
         * 4:0   - FIR2RAM for deviceptr1
         */
        mask0 = ((priv->inject_hlinesel & 0x3) << 28) |
                I5100_MEMXEINJMSK0_EINJEN |
                ((priv->inject_eccmask1 & 0xffff) << 10) |
                ((priv->inject_deviceptr2 & 0x1f) << 5) |
                (priv->inject_deviceptr1 & 0x1f);

        /* MEM[1:0]EINJMSK1
         * 15:0  - XORMASK2 for deviceptr2
         */
        mask1 = priv->inject_eccmask2;

        if (priv->inject_channel == 0) {
                pci_write_config_dword(priv->mc, I5100_MEM0EINJMSK0, mask0);
                pci_write_config_word(priv->mc, I5100_MEM0EINJMSK1, mask1);
        } else {
                pci_write_config_dword(priv->mc, I5100_MEM1EINJMSK0, mask0);
                pci_write_config_word(priv->mc, I5100_MEM1EINJMSK1, mask1);
        }

        /* Error Injection Response Function
         * Intel 5100 Memory Controller Hub Chipset (318378) datasheet
         * hints about this register but carry no data about them. All
         * data regarding device 19 is based on experimentation and the
         * Intel 7300 Chipset Memory Controller Hub (318082) datasheet
         * which appears to be accurate for the i5100 in this area.
         *
         * The injection code don't work without setting this register.
         * The register needs to be flipped off then on else the hardware
         * will only perform the first injection.
         *
         * Stop condition bits 7:4
         * 1010 - Stop after one injection
         * 1011 - Never stop injecting faults
         *
         * Start condition bits 3:0
         * 1010 - Never start
         * 1011 - Start immediately
         */
        pci_write_config_byte(priv->einj, I5100_DINJ0, 0xaa);
        pci_write_config_byte(priv->einj, I5100_DINJ0, 0xab);
}

#define to_mci(k) container_of(k, struct mem_ctl_info, dev)
static ssize_t inject_enable_write(struct file *file, const char __user *data,
                size_t count, loff_t *ppos)
{
        struct device *dev = file->private_data;
        struct mem_ctl_info *mci = to_mci(dev);

        i5100_do_inject(mci);

        return count;
}

static const struct file_operations i5100_inject_enable_fops = {
        .open = simple_open,
        .write = inject_enable_write,
        .llseek = generic_file_llseek,
};

static int i5100_setup_debugfs(struct mem_ctl_info *mci)
{
        struct i5100_priv *priv = mci->pvt_info;

        if (!i5100_debugfs)
                return -ENODEV;

        priv->debugfs = edac_debugfs_create_dir_at(mci->bus->name, i5100_debugfs);

        if (!priv->debugfs)
                return -ENOMEM;

        edac_debugfs_create_x8("inject_channel", S_IRUGO | S_IWUSR, priv->debugfs,
                                &priv->inject_channel);
        edac_debugfs_create_x8("inject_hlinesel", S_IRUGO | S_IWUSR, priv->debugfs,
                                &priv->inject_hlinesel);
        edac_debugfs_create_x8("inject_deviceptr1", S_IRUGO | S_IWUSR, priv->debugfs,
                                &priv->inject_deviceptr1);
        edac_debugfs_create_x8("inject_deviceptr2", S_IRUGO | S_IWUSR, priv->debugfs,
                                &priv->inject_deviceptr2);
        edac_debugfs_create_x16("inject_eccmask1", S_IRUGO | S_IWUSR, priv->debugfs,
                                &priv->inject_eccmask1);
        edac_debugfs_create_x16("inject_eccmask2", S_IRUGO | S_IWUSR, priv->debugfs,
                                &priv->inject_eccmask2);
        edac_debugfs_create_file("inject_enable", S_IWUSR, priv->debugfs,
                                &mci->dev, &i5100_inject_enable_fops);

        return 0;

}

static int i5100_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
        int rc;
        struct mem_ctl_info *mci;
        struct edac_mc_layer layers[2];
        struct i5100_priv *priv;
        struct pci_dev *ch0mm, *ch1mm, *einj;
        int ret = 0;
        u32 dw;
        int ranksperch;

        if (PCI_FUNC(pdev->devfn) != 1)
                return -ENODEV;

        rc = pci_enable_device(pdev);
        if (rc < 0) {
                ret = rc;
                goto bail;
        }

        /* ECC enabled? */
        pci_read_config_dword(pdev, I5100_MC, &dw);
        if (!i5100_mc_errdeten(dw)) {
                printk(KERN_INFO "i5100_edac: ECC not enabled.\n");
                ret = -ENODEV;
                goto bail_pdev;
        }

        /* figure out how many ranks, from strapped state of 48GB_Mode input */
        pci_read_config_dword(pdev, I5100_MS, &dw);
        ranksperch = !!(dw & (1 << 8)) * 2 + 4;

        /* enable error reporting... */
        pci_read_config_dword(pdev, I5100_EMASK_MEM, &dw);
        dw &= ~I5100_FERR_NF_MEM_ANY_MASK;
        pci_write_config_dword(pdev, I5100_EMASK_MEM, dw);

        /* device 21, func 0, Channel 0 Memory Map, Error Flag/Mask, etc... */
        ch0mm = pci_get_device_func(PCI_VENDOR_ID_INTEL,
                                    PCI_DEVICE_ID_INTEL_5100_21, 0);
        if (!ch0mm) {
                ret = -ENODEV;
                goto bail_pdev;
        }

        rc = pci_enable_device(ch0mm);
        if (rc < 0) {
                ret = rc;
                goto bail_ch0;
        }

        /* device 22, func 0, Channel 1 Memory Map, Error Flag/Mask, etc... */
        ch1mm = pci_get_device_func(PCI_VENDOR_ID_INTEL,
                                    PCI_DEVICE_ID_INTEL_5100_22, 0);
        if (!ch1mm) {
                ret = -ENODEV;
                goto bail_disable_ch0;
        }

        rc = pci_enable_device(ch1mm);
        if (rc < 0) {
                ret = rc;
                goto bail_ch1;
        }

        layers[0].type = EDAC_MC_LAYER_CHANNEL;
        layers[0].size = 2;
        layers[0].is_virt_csrow = false;
        layers[1].type = EDAC_MC_LAYER_SLOT;
        layers[1].size = ranksperch;
        layers[1].is_virt_csrow = true;
        mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers,
                            sizeof(*priv));
        if (!mci) {
                ret = -ENOMEM;
                goto bail_disable_ch1;
        }


        /* device 19, func 0, Error injection */
        einj = pci_get_device_func(PCI_VENDOR_ID_INTEL,
                                    PCI_DEVICE_ID_INTEL_5100_19, 0);
        if (!einj) {
                ret = -ENODEV;
                goto bail_mc_free;
        }

        rc = pci_enable_device(einj);
        if (rc < 0) {
                ret = rc;
                goto bail_einj;
        }

        mci->pdev = &pdev->dev;

        priv = mci->pvt_info;
        priv->ranksperchan = ranksperch;
        priv->mc = pdev;
        priv->ch0mm = ch0mm;
        priv->ch1mm = ch1mm;
        priv->einj = einj;

        INIT_DELAYED_WORK(&(priv->i5100_scrubbing), i5100_refresh_scrubbing);

        /* If scrubbing was already enabled by the bios, start maintaining it */
        pci_read_config_dword(pdev, I5100_MC, &dw);
        if (i5100_mc_scrben(dw)) {
                priv->scrub_enable = 1;
                schedule_delayed_work(&(priv->i5100_scrubbing),
                                      I5100_SCRUB_REFRESH_RATE);
        }

        i5100_init_dimm_layout(pdev, mci);
        i5100_init_interleaving(pdev, mci);

        mci->mtype_cap = MEM_FLAG_FB_DDR2;
        mci->edac_ctl_cap = EDAC_FLAG_SECDED;
        mci->edac_cap = EDAC_FLAG_SECDED;
        mci->mod_name = "i5100_edac.c";
        mci->ctl_name = "i5100";
        mci->dev_name = pci_name(pdev);
        mci->ctl_page_to_phys = NULL;

        mci->edac_check = i5100_check_error;
        mci->set_sdram_scrub_rate = i5100_set_scrub_rate;
        mci->get_sdram_scrub_rate = i5100_get_scrub_rate;

        priv->inject_channel = 0;
        priv->inject_hlinesel = 0;
        priv->inject_deviceptr1 = 0;
        priv->inject_deviceptr2 = 0;
        priv->inject_eccmask1 = 0;
        priv->inject_eccmask2 = 0;

        i5100_init_csrows(mci);

        /* this strange construction seems to be in every driver, dunno why */
        switch (edac_op_state) {
        case EDAC_OPSTATE_POLL:
        case EDAC_OPSTATE_NMI:
                break;
        default:
                edac_op_state = EDAC_OPSTATE_POLL;
                break;
        }

        if (edac_mc_add_mc(mci)) {
                ret = -ENODEV;
                goto bail_scrub;
        }

        i5100_setup_debugfs(mci);

        return ret;

bail_scrub:
        priv->scrub_enable = 0;
        cancel_delayed_work_sync(&(priv->i5100_scrubbing));
        pci_disable_device(einj);

bail_einj:
        pci_dev_put(einj);

bail_mc_free:
        edac_mc_free(mci);

bail_disable_ch1:
        pci_disable_device(ch1mm);

bail_ch1:
        pci_dev_put(ch1mm);

bail_disable_ch0:
        pci_disable_device(ch0mm);

bail_ch0:
        pci_dev_put(ch0mm);

bail_pdev:
        pci_disable_device(pdev);

bail:
        return ret;
}

static void i5100_remove_one(struct pci_dev *pdev)
{
        struct mem_ctl_info *mci;
        struct i5100_priv *priv;

        mci = edac_mc_del_mc(&pdev->dev);

        if (!mci)
                return;

        priv = mci->pvt_info;

        edac_debugfs_remove_recursive(priv->debugfs);

        priv->scrub_enable = 0;
        cancel_delayed_work_sync(&(priv->i5100_scrubbing));

        pci_disable_device(pdev);
        pci_disable_device(priv->ch0mm);
        pci_disable_device(priv->ch1mm);
        pci_disable_device(priv->einj);
        pci_dev_put(priv->ch0mm);
        pci_dev_put(priv->ch1mm);
        pci_dev_put(priv->einj);

        edac_mc_free(mci);
}

static const struct pci_device_id i5100_pci_tbl[] = {
        /* Device 16, Function 0, Channel 0 Memory Map, Error Flag/Mask, ... */
        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5100_16) },
        { 0, }
};
MODULE_DEVICE_TABLE(pci, i5100_pci_tbl);

static struct pci_driver i5100_driver = {
        .name = KBUILD_BASENAME,
        .probe = i5100_init_one,
        .remove = i5100_remove_one,
        .id_table = i5100_pci_tbl,
};

static int __init i5100_init(void)
{
        int pci_rc;

        i5100_debugfs = edac_debugfs_create_dir_at("i5100_edac", NULL);

        pci_rc = pci_register_driver(&i5100_driver);
        return (pci_rc < 0) ? pci_rc : 0;
}

static void __exit i5100_exit(void)
{
        edac_debugfs_remove(i5100_debugfs);

        pci_unregister_driver(&i5100_driver);
}

module_init(i5100_init);
module_exit(i5100_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arthur Jones <ajones@riverbed.com>");
MODULE_DESCRIPTION("MC Driver for Intel I5100 memory controllers");