qib_eeprom.c

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/*
 * Copyright (c) 2012 Intel Corporation. All rights reserved.
 * Copyright (c) 2006 - 2012 QLogic Corporation. All rights reserved.
 * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/vmalloc.h>

#include "qib.h"

/*
 * Functions specific to the serial EEPROM on cards handled by ib_qib.
 * The actual serail interface code is in qib_twsi.c. This file is a client
 */

int qib_eeprom_read(struct qib_devdata *dd, u8 eeprom_offset,
            void *buff, int len)
{
    int ret;

    ret = mutex_lock_interruptible(&dd->eep_lock);
    if (!ret) {
        ret = qib_twsi_reset(dd);
        if (ret)
            qib_dev_err(dd, "EEPROM Reset for read failed\n");
        else
            ret = qib_twsi_blk_rd(dd, dd->twsi_eeprom_dev,
                          eeprom_offset, buff, len);
        mutex_unlock(&dd->eep_lock);
    }

    return ret;
}

/*
 * Actually update the eeprom, first doing write enable if
 * needed, then restoring write enable state.
 * Must be called with eep_lock held
 */
static int eeprom_write_with_enable(struct qib_devdata *dd, u8 offset,
             const void *buf, int len)
{
    int ret, pwen;

    pwen = dd->f_eeprom_wen(dd, 1);
    ret = qib_twsi_reset(dd);
    if (ret)
        qib_dev_err(dd, "EEPROM Reset for write failed\n");
    else
        ret = qib_twsi_blk_wr(dd, dd->twsi_eeprom_dev,
                      offset, buf, len);
    dd->f_eeprom_wen(dd, pwen);
    return ret;
}

int qib_eeprom_write(struct qib_devdata *dd, u8 eeprom_offset,
             const void *buff, int len)
{
    int ret;

    ret = mutex_lock_interruptible(&dd->eep_lock);
    if (!ret) {
        ret = eeprom_write_with_enable(dd, eeprom_offset, buff, len);
        mutex_unlock(&dd->eep_lock);
    }

    return ret;
}

static u8 flash_csum(struct qib_flash *ifp, int adjust)
{
    u8 *ip = (u8 *) ifp;
    u8 csum = 0, len;

    /*
     * Limit length checksummed to max length of actual data.
     * Checksum of erased eeprom will still be bad, but we avoid
     * reading past the end of the buffer we were passed.
     */
    len = ifp->if_length;
    if (len > sizeof(struct qib_flash))
        len = sizeof(struct qib_flash);
    while (len--)
        csum += *ip++;
    csum -= ifp->if_csum;
    csum = ~csum;
    if (adjust)
        ifp->if_csum = csum;

    return csum;
}

void qib_get_eeprom_info(struct qib_devdata *dd)
{
    void *buf;
    struct qib_flash *ifp;
    __be64 guid;
    int len, eep_stat;
    u8 csum, *bguid;
    int t = dd->unit;
    struct qib_devdata *dd0 = qib_lookup(0);

    if (t && dd0->nguid > 1 && t <= dd0->nguid) {
        u8 oguid;
        dd->base_guid = dd0->base_guid;
        bguid = (u8 *) &dd->base_guid;

        oguid = bguid[7];
        bguid[7] += t;
        if (oguid > bguid[7]) {
            if (bguid[6] == 0xff) {
                if (bguid[5] == 0xff) {
                    qib_dev_err(dd,
                        "Can't set %s GUID from base, wraps to OUI!\n",
                        qib_get_unit_name(t));
                    dd->base_guid = 0;
                    goto bail;
                }
                bguid[5]++;
            }
            bguid[6]++;
        }
        dd->nguid = 1;
        goto bail;
    }

    /*
     * Read full flash, not just currently used part, since it may have
     * been written with a newer definition.
     * */
    len = sizeof(struct qib_flash);
    buf = vmalloc(len);
    if (!buf) {
        qib_dev_err(dd,
            "Couldn't allocate memory to read %u bytes from eeprom for GUID\n",
            len);
        goto bail;
    }

    /*
     * Use "public" eeprom read function, which does locking and
     * figures out device. This will migrate to chip-specific.
     */
    eep_stat = qib_eeprom_read(dd, 0, buf, len);

    if (eep_stat) {
        qib_dev_err(dd, "Failed reading GUID from eeprom\n");
        goto done;
    }
    ifp = (struct qib_flash *)buf;

    csum = flash_csum(ifp, 0);
    if (csum != ifp->if_csum) {
        qib_devinfo(dd->pcidev,
            "Bad I2C flash checksum: 0x%x, not 0x%x\n",
            csum, ifp->if_csum);
        goto done;
    }
    if (*(__be64 *) ifp->if_guid == cpu_to_be64(0) ||
        *(__be64 *) ifp->if_guid == ~cpu_to_be64(0)) {
        qib_dev_err(dd,
            "Invalid GUID %llx from flash; ignoring\n",
            *(unsigned long long *) ifp->if_guid);
        /* don't allow GUID if all 0 or all 1's */
        goto done;
    }

    /* complain, but allow it */
    if (*(u64 *) ifp->if_guid == 0x100007511000000ULL)
        qib_devinfo(dd->pcidev,
            "Warning, GUID %llx is default, probably not correct!\n",
            *(unsigned long long *) ifp->if_guid);

    bguid = ifp->if_guid;
    if (!bguid[0] && !bguid[1] && !bguid[2]) {
        /*
         * Original incorrect GUID format in flash; fix in
         * core copy, by shifting up 2 octets; don't need to
         * change top octet, since both it and shifted are 0.
         */
        bguid[1] = bguid[3];
        bguid[2] = bguid[4];
        bguid[3] = 0;
        bguid[4] = 0;
        guid = *(__be64 *) ifp->if_guid;
    } else
        guid = *(__be64 *) ifp->if_guid;
    dd->base_guid = guid;
    dd->nguid = ifp->if_numguid;
    /*
     * Things are slightly complicated by the desire to transparently
     * support both the Pathscale 10-digit serial number and the QLogic
     * 13-character version.
     */
    if ((ifp->if_fversion > 1) && ifp->if_sprefix[0] &&
        ((u8 *) ifp->if_sprefix)[0] != 0xFF) {
        char *snp = dd->serial;

        /*
         * This board has a Serial-prefix, which is stored
         * elsewhere for backward-compatibility.
         */
        memcpy(snp, ifp->if_sprefix, sizeof ifp->if_sprefix);
        snp[sizeof ifp->if_sprefix] = '\0';
        len = strlen(snp);
        snp += len;
        len = (sizeof dd->serial) - len;
        if (len > sizeof ifp->if_serial)
            len = sizeof ifp->if_serial;
        memcpy(snp, ifp->if_serial, len);
    } else
        memcpy(dd->serial, ifp->if_serial,
               sizeof ifp->if_serial);
    if (!strstr(ifp->if_comment, "Tested successfully"))
        qib_dev_err(dd,
            "Board SN %s did not pass functional test: %s\n",
            dd->serial, ifp->if_comment);

    memcpy(&dd->eep_st_errs, &ifp->if_errcntp, QIB_EEP_LOG_CNT);
    /*
     * Power-on (actually "active") hours are kept as little-endian value
     * in EEPROM, but as seconds in a (possibly as small as 24-bit)
     * atomic_t while running.
     */
    atomic_set(&dd->active_time, 0);
    dd->eep_hrs = ifp->if_powerhour[0] | (ifp->if_powerhour[1] << 8);

done:
    vfree(buf);

bail:;
}

int qib_update_eeprom_log(struct qib_devdata *dd)
{
    void *buf;
    struct qib_flash *ifp;
    int len, hi_water;
    uint32_t new_time, new_hrs;
    u8 csum;
    int ret, idx;
    unsigned long flags;

    /* first, check if we actually need to do anything. */
    ret = 0;
    for (idx = 0; idx < QIB_EEP_LOG_CNT; ++idx) {
        if (dd->eep_st_new_errs[idx]) {
            ret = 1;
            break;
        }
    }
    new_time = atomic_read(&dd->active_time);

    if (ret == 0 && new_time < 3600)
        goto bail;

    /*
     * The quick-check above determined that there is something worthy
     * of logging, so get current contents and do a more detailed idea.
     * read full flash, not just currently used part, since it may have
     * been written with a newer definition
     */
    len = sizeof(struct qib_flash);
    buf = vmalloc(len);
    ret = 1;
    if (!buf) {
        qib_dev_err(dd,
            "Couldn't allocate memory to read %u bytes from eeprom for logging\n",
            len);
        goto bail;
    }

    /* Grab semaphore and read current EEPROM. If we get an
     * error, let go, but if not, keep it until we finish write.
     */
    ret = mutex_lock_interruptible(&dd->eep_lock);
    if (ret) {
        qib_dev_err(dd, "Unable to acquire EEPROM for logging\n");
        goto free_bail;
    }
    ret = qib_twsi_blk_rd(dd, dd->twsi_eeprom_dev, 0, buf, len);
    if (ret) {
        mutex_unlock(&dd->eep_lock);
        qib_dev_err(dd, "Unable read EEPROM for logging\n");
        goto free_bail;
    }
    ifp = (struct qib_flash *)buf;

    csum = flash_csum(ifp, 0);
    if (csum != ifp->if_csum) {
        mutex_unlock(&dd->eep_lock);
        qib_dev_err(dd, "EEPROM cks err (0x%02X, S/B 0x%02X)\n",
                csum, ifp->if_csum);
        ret = 1;
        goto free_bail;
    }
    hi_water = 0;
    spin_lock_irqsave(&dd->eep_st_lock, flags);
    for (idx = 0; idx < QIB_EEP_LOG_CNT; ++idx) {
        int new_val = dd->eep_st_new_errs[idx];
        if (new_val) {
            /*
             * If we have seen any errors, add to EEPROM values
             * We need to saturate at 0xFF (255) and we also
             * would need to adjust the checksum if we were
             * trying to minimize EEPROM traffic
             * Note that we add to actual current count in EEPROM,
             * in case it was altered while we were running.
             */
            new_val += ifp->if_errcntp[idx];
            if (new_val > 0xFF)
                new_val = 0xFF;
            if (ifp->if_errcntp[idx] != new_val) {
                ifp->if_errcntp[idx] = new_val;
                hi_water = offsetof(struct qib_flash,
                            if_errcntp) + idx;
            }
            /*
             * update our shadow (used to minimize EEPROM
             * traffic), to match what we are about to write.
             */
            dd->eep_st_errs[idx] = new_val;
            dd->eep_st_new_errs[idx] = 0;
        }
    }
    /*
     * Now update active-time. We would like to round to the nearest hour
     * but unless atomic_t are sure to be proper signed ints we cannot,
     * because we need to account for what we "transfer" to EEPROM and
     * if we log an hour at 31 minutes, then we would need to set
     * active_time to -29 to accurately count the _next_ hour.
     */
    if (new_time >= 3600) {
        new_hrs = new_time / 3600;
        atomic_sub((new_hrs * 3600), &dd->active_time);
        new_hrs += dd->eep_hrs;
        if (new_hrs > 0xFFFF)
            new_hrs = 0xFFFF;
        dd->eep_hrs = new_hrs;
        if ((new_hrs & 0xFF) != ifp->if_powerhour[0]) {
            ifp->if_powerhour[0] = new_hrs & 0xFF;
            hi_water = offsetof(struct qib_flash, if_powerhour);
        }
        if ((new_hrs >> 8) != ifp->if_powerhour[1]) {
            ifp->if_powerhour[1] = new_hrs >> 8;
            hi_water = offsetof(struct qib_flash, if_powerhour) + 1;
        }
    }
    /*
     * There is a tiny possibility that we could somehow fail to write
     * the EEPROM after updating our shadows, but problems from holding
     * the spinlock too long are a much bigger issue.
     */
    spin_unlock_irqrestore(&dd->eep_st_lock, flags);
    if (hi_water) {
        /* we made some change to the data, uopdate cksum and write */
        csum = flash_csum(ifp, 1);
        ret = eeprom_write_with_enable(dd, 0, buf, hi_water + 1);
    }
    mutex_unlock(&dd->eep_lock);
    if (ret)
        qib_dev_err(dd, "Failed updating EEPROM\n");

free_bail:
    vfree(buf);
bail:
    return ret;
}

void qib_inc_eeprom_err(struct qib_devdata *dd, u32 eidx, u32 incr)
{
    uint new_val;
    unsigned long flags;

    spin_lock_irqsave(&dd->eep_st_lock, flags);
    new_val = dd->eep_st_new_errs[eidx] + incr;
    if (new_val > 255)
        new_val = 255;
    dd->eep_st_new_errs[eidx] = new_val;
    spin_unlock_irqrestore(&dd->eep_st_lock, flags);
}