umem.c

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/*
 * mm.c - Micro Memory(tm) PCI memory board block device driver - v2.3
 *
 * (C) 2001 San Mehat <[email protected]>
 * (C) 2001 Johannes Erdfelt <[email protected]>
 * (C) 2001 NeilBrown <[email protected]>
 *
 * This driver for the Micro Memory PCI Memory Module with Battery Backup
 * is Copyright Micro Memory Inc 2001-2002.  All rights reserved.
 *
 * This driver is released to the public under the terms of the
 *  GNU GENERAL PUBLIC LICENSE version 2
 * See the file COPYING for details.
 *
 * This driver provides a standard block device interface for Micro Memory(tm)
 * PCI based RAM boards.
 * 10/05/01: Phap Nguyen - Rebuilt the driver
 * 10/22/01: Phap Nguyen - v2.1 Added disk partitioning
 * 29oct2001:NeilBrown   - Use make_request_fn instead of request_fn
 *                       - use stand disk partitioning (so fdisk works).
 * 08nov2001:NeilBrown   - change driver name from "mm" to "umem"
 *           - incorporate into main kernel
 * 08apr2002:NeilBrown   - Move some of interrupt handle to tasklet
 *           - use spin_lock_bh instead of _irq
 *           - Never block on make_request.  queue
 *             bh's instead.
 *           - unregister umem from devfs at mod unload
 *           - Change version to 2.3
 * 07Nov2001:Phap Nguyen - Select pci read command: 06, 12, 15 (Decimal)
 * 07Jan2002: P. Nguyen  - Used PCI Memory Write & Invalidate for DMA
 * 15May2002:NeilBrown   - convert to bio for 2.5
 * 17May2002:NeilBrown   - remove init_mem initialisation.  Instead detect
 *           - a sequence of writes that cover the card, and
 *           - set initialised bit then.
 */

#undef DEBUG    /* #define DEBUG if you want debugging info (pr_debug) */
#include <linux/fs.h>
#include <linux/bio.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/gfp.h>
#include <linux/ioctl.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>

#include <linux/fcntl.h>        /* O_ACCMODE */
#include <linux/hdreg.h>  /* HDIO_GETGEO */

#include "umem.h"

#include <asm/uaccess.h>
#include <asm/io.h>

#define MM_MAXCARDS 4
#define MM_RAHEAD 2      /* two sectors */
#define MM_BLKSIZE 1024  /* 1k blocks */
#define MM_HARDSECT 512  /* 512-byte hardware sectors */
#define MM_SHIFT 6       /* max 64 partitions on 4 cards  */

/*
 * Version Information
 */

#define DRIVER_NAME "umem"
#define DRIVER_VERSION  "v2.3"
#define DRIVER_AUTHOR   "San Mehat, Johannes Erdfelt, NeilBrown"
#define DRIVER_DESC "Micro Memory(tm) PCI memory board block driver"

static int debug;
/* #define HW_TRACE(x)     writeb(x,cards[0].csr_remap + MEMCTRLSTATUS_MAGIC) */
#define HW_TRACE(x)

#define DEBUG_LED_ON_TRANSFER   0x01
#define DEBUG_BATTERY_POLLING   0x02

module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Debug bitmask");

static int pci_read_cmd = 0x0C;     /* Read Multiple */
module_param(pci_read_cmd, int, 0);
MODULE_PARM_DESC(pci_read_cmd, "PCI read command");

static int pci_write_cmd = 0x0F;    /* Write and Invalidate */
module_param(pci_write_cmd, int, 0);
MODULE_PARM_DESC(pci_write_cmd, "PCI write command");

static int pci_cmds;

static int major_nr;

#include <linux/blkdev.h>
#include <linux/blkpg.h>

struct cardinfo {
    struct pci_dev  *dev;

    unsigned char   __iomem *csr_remap;
    unsigned int    mm_size;  /* size in kbytes */

    unsigned int    init_size; /* initial segment, in sectors,
                    * that we know to
                    * have been written
                    */
    struct bio  *bio, *currentbio, **biotail;
    int     current_idx;
    sector_t    current_sector;

    struct request_queue *queue;

    struct mm_page {
        dma_addr_t      page_dma;
        struct mm_dma_desc  *desc;
        int         cnt, headcnt;
        struct bio      *bio, **biotail;
        int         idx;
    } mm_pages[2];
#define DESC_PER_PAGE ((PAGE_SIZE*2)/sizeof(struct mm_dma_desc))

    int  Active, Ready;

    struct tasklet_struct   tasklet;
    unsigned int dma_status;

    struct {
        int     good;
        int     warned;
        unsigned long   last_change;
    } battery[2];

    spinlock_t  lock;
    int     check_batteries;

    int     flags;
};

static struct cardinfo cards[MM_MAXCARDS];
static struct timer_list battery_timer;

static int num_cards;

static struct gendisk *mm_gendisk[MM_MAXCARDS];

static void check_batteries(struct cardinfo *card);

static int get_userbit(struct cardinfo *card, int bit)
{
    unsigned char led;

    led = readb(card->csr_remap + MEMCTRLCMD_LEDCTRL);
    return led & bit;
}

static int set_userbit(struct cardinfo *card, int bit, unsigned char state)
{
    unsigned char led;

    led = readb(card->csr_remap + MEMCTRLCMD_LEDCTRL);
    if (state)
        led |= bit;
    else
        led &= ~bit;
    writeb(led, card->csr_remap + MEMCTRLCMD_LEDCTRL);

    return 0;
}

/*
 * NOTE: For the power LED, use the LED_POWER_* macros since they differ
 */
static void set_led(struct cardinfo *card, int shift, unsigned char state)
{
    unsigned char led;

    led = readb(card->csr_remap + MEMCTRLCMD_LEDCTRL);
    if (state == LED_FLIP)
        led ^= (1<<shift);
    else {
        led &= ~(0x03 << shift);
        led |= (state << shift);
    }
    writeb(led, card->csr_remap + MEMCTRLCMD_LEDCTRL);

}

#ifdef MM_DIAG
static void dump_regs(struct cardinfo *card)
{
    unsigned char *p;
    int i, i1;

    p = card->csr_remap;
    for (i = 0; i < 8; i++) {
        printk(KERN_DEBUG "%p   ", p);

        for (i1 = 0; i1 < 16; i1++)
            printk("%02x ", *p++);

        printk("\n");
    }
}
#endif

static void dump_dmastat(struct cardinfo *card, unsigned int dmastat)
{
    dev_printk(KERN_DEBUG, &card->dev->dev, "DMAstat - ");
    if (dmastat & DMASCR_ANY_ERR)
        printk(KERN_CONT "ANY_ERR ");
    if (dmastat & DMASCR_MBE_ERR)
        printk(KERN_CONT "MBE_ERR ");
    if (dmastat & DMASCR_PARITY_ERR_REP)
        printk(KERN_CONT "PARITY_ERR_REP ");
    if (dmastat & DMASCR_PARITY_ERR_DET)
        printk(KERN_CONT "PARITY_ERR_DET ");
    if (dmastat & DMASCR_SYSTEM_ERR_SIG)
        printk(KERN_CONT "SYSTEM_ERR_SIG ");
    if (dmastat & DMASCR_TARGET_ABT)
        printk(KERN_CONT "TARGET_ABT ");
    if (dmastat & DMASCR_MASTER_ABT)
        printk(KERN_CONT "MASTER_ABT ");
    if (dmastat & DMASCR_CHAIN_COMPLETE)
        printk(KERN_CONT "CHAIN_COMPLETE ");
    if (dmastat & DMASCR_DMA_COMPLETE)
        printk(KERN_CONT "DMA_COMPLETE ");
    printk("\n");
}

/*
 * Theory of request handling
 *
 * Each bio is assigned to one mm_dma_desc - which may not be enough FIXME
 * We have two pages of mm_dma_desc, holding about 64 descriptors
 * each.  These are allocated at init time.
 * One page is "Ready" and is either full, or can have request added.
 * The other page might be "Active", which DMA is happening on it.
 *
 * Whenever IO on the active page completes, the Ready page is activated
 * and the ex-Active page is clean out and made Ready.
 * Otherwise the Ready page is only activated when it becomes full.
 *
 * If a request arrives while both pages a full, it is queued, and b_rdev is
 * overloaded to record whether it was a read or a write.
 *
 * The interrupt handler only polls the device to clear the interrupt.
 * The processing of the result is done in a tasklet.
 */

static void mm_start_io(struct cardinfo *card)
{
    /* we have the lock, we know there is
     * no IO active, and we know that card->Active
     * is set
     */
    struct mm_dma_desc *desc;
    struct mm_page *page;
    int offset;

    /* make the last descriptor end the chain */
    page = &card->mm_pages[card->Active];
    pr_debug("start_io: %d %d->%d\n",
        card->Active, page->headcnt, page->cnt - 1);
    desc = &page->desc[page->cnt-1];

    desc->control_bits |= cpu_to_le32(DMASCR_CHAIN_COMP_EN);
    desc->control_bits &= ~cpu_to_le32(DMASCR_CHAIN_EN);
    desc->sem_control_bits = desc->control_bits;


    if (debug & DEBUG_LED_ON_TRANSFER)
        set_led(card, LED_REMOVE, LED_ON);

    desc = &page->desc[page->headcnt];
    writel(0, card->csr_remap + DMA_PCI_ADDR);
    writel(0, card->csr_remap + DMA_PCI_ADDR + 4);

    writel(0, card->csr_remap + DMA_LOCAL_ADDR);
    writel(0, card->csr_remap + DMA_LOCAL_ADDR + 4);

    writel(0, card->csr_remap + DMA_TRANSFER_SIZE);
    writel(0, card->csr_remap + DMA_TRANSFER_SIZE + 4);

    writel(0, card->csr_remap + DMA_SEMAPHORE_ADDR);
    writel(0, card->csr_remap + DMA_SEMAPHORE_ADDR + 4);

    offset = ((char *)desc) - ((char *)page->desc);
    writel(cpu_to_le32((page->page_dma+offset) & 0xffffffff),
           card->csr_remap + DMA_DESCRIPTOR_ADDR);
    /* Force the value to u64 before shifting otherwise >> 32 is undefined C
     * and on some ports will do nothing ! */
    writel(cpu_to_le32(((u64)page->page_dma)>>32),
           card->csr_remap + DMA_DESCRIPTOR_ADDR + 4);

    /* Go, go, go */
    writel(cpu_to_le32(DMASCR_GO | DMASCR_CHAIN_EN | pci_cmds),
           card->csr_remap + DMA_STATUS_CTRL);
}

static int add_bio(struct cardinfo *card);

static void activate(struct cardinfo *card)
{
    /* if No page is Active, and Ready is
     * not empty, then switch Ready page
     * to active and start IO.
     * Then add any bh's that are available to Ready
     */

    do {
        while (add_bio(card))
            ;

        if (card->Active == -1 &&
            card->mm_pages[card->Ready].cnt > 0) {
            card->Active = card->Ready;
            card->Ready = 1-card->Ready;
            mm_start_io(card);
        }

    } while (card->Active == -1 && add_bio(card));
}

static inline void reset_page(struct mm_page *page)
{
    page->cnt = 0;
    page->headcnt = 0;
    page->bio = NULL;
    page->biotail = &page->bio;
}

/*
 * If there is room on Ready page, take
 * one bh off list and add it.
 * return 1 if there was room, else 0.
 */
static int add_bio(struct cardinfo *card)
{
    struct mm_page *p;
    struct mm_dma_desc *desc;
    dma_addr_t dma_handle;
    int offset;
    struct bio *bio;
    struct bio_vec *vec;
    int idx;
    int rw;
    int len;

    bio = card->currentbio;
    if (!bio && card->bio) {
        card->currentbio = card->bio;
        card->current_idx = card->bio->bi_idx;
        card->current_sector = card->bio->bi_sector;
        card->bio = card->bio->bi_next;
        if (card->bio == NULL)
            card->biotail = &card->bio;
        card->currentbio->bi_next = NULL;
        return 1;
    }
    if (!bio)
        return 0;
    idx = card->current_idx;

    rw = bio_rw(bio);
    if (card->mm_pages[card->Ready].cnt >= DESC_PER_PAGE)
        return 0;

    vec = bio_iovec_idx(bio, idx);
    len = vec->bv_len;
    dma_handle = pci_map_page(card->dev,
                  vec->bv_page,
                  vec->bv_offset,
                  len,
                  (rw == READ) ?
                  PCI_DMA_FROMDEVICE : PCI_DMA_TODEVICE);

    p = &card->mm_pages[card->Ready];
    desc = &p->desc[p->cnt];
    p->cnt++;
    if (p->bio == NULL)
        p->idx = idx;
    if ((p->biotail) != &bio->bi_next) {
        *(p->biotail) = bio;
        p->biotail = &(bio->bi_next);
        bio->bi_next = NULL;
    }

    desc->data_dma_handle = dma_handle;

    desc->pci_addr = cpu_to_le64((u64)desc->data_dma_handle);
    desc->local_addr = cpu_to_le64(card->current_sector << 9);
    desc->transfer_size = cpu_to_le32(len);
    offset = (((char *)&desc->sem_control_bits) - ((char *)p->desc));
    desc->sem_addr = cpu_to_le64((u64)(p->page_dma+offset));
    desc->zero1 = desc->zero2 = 0;
    offset = (((char *)(desc+1)) - ((char *)p->desc));
    desc->next_desc_addr = cpu_to_le64(p->page_dma+offset);
    desc->control_bits = cpu_to_le32(DMASCR_GO|DMASCR_ERR_INT_EN|
                     DMASCR_PARITY_INT_EN|
                     DMASCR_CHAIN_EN |
                     DMASCR_SEM_EN |
                     pci_cmds);
    if (rw == WRITE)
        desc->control_bits |= cpu_to_le32(DMASCR_TRANSFER_READ);
    desc->sem_control_bits = desc->control_bits;

    card->current_sector += (len >> 9);
    idx++;
    card->current_idx = idx;
    if (idx >= bio->bi_vcnt)
        card->currentbio = NULL;

    return 1;
}

static void process_page(unsigned long data)
{
    /* check if any of the requests in the page are DMA_COMPLETE,
     * and deal with them appropriately.
     * If we find a descriptor without DMA_COMPLETE in the semaphore, then
     * dma must have hit an error on that descriptor, so use dma_status
     * instead and assume that all following descriptors must be re-tried.
     */
    struct mm_page *page;
    struct bio *return_bio = NULL;
    struct cardinfo *card = (struct cardinfo *)data;
    unsigned int dma_status = card->dma_status;

    spin_lock_bh(&card->lock);
    if (card->Active < 0)
        goto out_unlock;
    page = &card->mm_pages[card->Active];

    while (page->headcnt < page->cnt) {
        struct bio *bio = page->bio;
        struct mm_dma_desc *desc = &page->desc[page->headcnt];
        int control = le32_to_cpu(desc->sem_control_bits);
        int last = 0;
        int idx;

        if (!(control & DMASCR_DMA_COMPLETE)) {
            control = dma_status;
            last = 1;
        }
        page->headcnt++;
        idx = page->idx;
        page->idx++;
        if (page->idx >= bio->bi_vcnt) {
            page->bio = bio->bi_next;
            if (page->bio)
                page->idx = page->bio->bi_idx;
        }

        pci_unmap_page(card->dev, desc->data_dma_handle,
                   bio_iovec_idx(bio, idx)->bv_len,
                 (control & DMASCR_TRANSFER_READ) ?
                PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
        if (control & DMASCR_HARD_ERROR) {
            /* error */
            clear_bit(BIO_UPTODATE, &bio->bi_flags);
            dev_printk(KERN_WARNING, &card->dev->dev,
                "I/O error on sector %d/%d\n",
                le32_to_cpu(desc->local_addr)>>9,
                le32_to_cpu(desc->transfer_size));
            dump_dmastat(card, control);
        } else if ((bio->bi_rw & REQ_WRITE) &&
               le32_to_cpu(desc->local_addr) >> 9 ==
                card->init_size) {
            card->init_size += le32_to_cpu(desc->transfer_size) >> 9;
            if (card->init_size >> 1 >= card->mm_size) {
                dev_printk(KERN_INFO, &card->dev->dev,
                    "memory now initialised\n");
                set_userbit(card, MEMORY_INITIALIZED, 1);
            }
        }
        if (bio != page->bio) {
            bio->bi_next = return_bio;
            return_bio = bio;
        }

        if (last)
            break;
    }

    if (debug & DEBUG_LED_ON_TRANSFER)
        set_led(card, LED_REMOVE, LED_OFF);

    if (card->check_batteries) {
        card->check_batteries = 0;
        check_batteries(card);
    }
    if (page->headcnt >= page->cnt) {
        reset_page(page);
        card->Active = -1;
        activate(card);
    } else {
        /* haven't finished with this one yet */
        pr_debug("do some more\n");
        mm_start_io(card);
    }
 out_unlock:
    spin_unlock_bh(&card->lock);

    while (return_bio) {
        struct bio *bio = return_bio;

        return_bio = bio->bi_next;
        bio->bi_next = NULL;
        bio_endio(bio, 0);
    }
}

static void mm_unplug(struct blk_plug_cb *cb, bool from_schedule)
{
    struct cardinfo *card = cb->data;

    spin_lock_irq(&card->lock);
    activate(card);
    spin_unlock_irq(&card->lock);
    kfree(cb);
}

static int mm_check_plugged(struct cardinfo *card)
{
    return !!blk_check_plugged(mm_unplug, card, sizeof(struct blk_plug_cb));
}

static void mm_make_request(struct request_queue *q, struct bio *bio)
{
    struct cardinfo *card = q->queuedata;
    pr_debug("mm_make_request %llu %u\n",
         (unsigned long long)bio->bi_sector, bio->bi_size);

    spin_lock_irq(&card->lock);
    *card->biotail = bio;
    bio->bi_next = NULL;
    card->biotail = &bio->bi_next;
    if (bio->bi_rw & REQ_SYNC || !mm_check_plugged(card))
        activate(card);
    spin_unlock_irq(&card->lock);

    return;
}

static irqreturn_t mm_interrupt(int irq, void *__card)
{
    struct cardinfo *card = (struct cardinfo *) __card;
    unsigned int dma_status;
    unsigned short cfg_status;

HW_TRACE(0x30);

    dma_status = le32_to_cpu(readl(card->csr_remap + DMA_STATUS_CTRL));

    if (!(dma_status & (DMASCR_ERROR_MASK | DMASCR_CHAIN_COMPLETE))) {
        /* interrupt wasn't for me ... */
        return IRQ_NONE;
    }

    /* clear COMPLETION interrupts */
    if (card->flags & UM_FLAG_NO_BYTE_STATUS)
        writel(cpu_to_le32(DMASCR_DMA_COMPLETE|DMASCR_CHAIN_COMPLETE),
               card->csr_remap + DMA_STATUS_CTRL);
    else
        writeb((DMASCR_DMA_COMPLETE|DMASCR_CHAIN_COMPLETE) >> 16,
               card->csr_remap + DMA_STATUS_CTRL + 2);

    /* log errors and clear interrupt status */
    if (dma_status & DMASCR_ANY_ERR) {
        unsigned int    data_log1, data_log2;
        unsigned int    addr_log1, addr_log2;
        unsigned char   stat, count, syndrome, check;

        stat = readb(card->csr_remap + MEMCTRLCMD_ERRSTATUS);

        data_log1 = le32_to_cpu(readl(card->csr_remap +
                        ERROR_DATA_LOG));
        data_log2 = le32_to_cpu(readl(card->csr_remap +
                        ERROR_DATA_LOG + 4));
        addr_log1 = le32_to_cpu(readl(card->csr_remap +
                        ERROR_ADDR_LOG));
        addr_log2 = readb(card->csr_remap + ERROR_ADDR_LOG + 4);

        count = readb(card->csr_remap + ERROR_COUNT);
        syndrome = readb(card->csr_remap + ERROR_SYNDROME);
        check = readb(card->csr_remap + ERROR_CHECK);

        dump_dmastat(card, dma_status);

        if (stat & 0x01)
            dev_printk(KERN_ERR, &card->dev->dev,
                "Memory access error detected (err count %d)\n",
                count);
        if (stat & 0x02)
            dev_printk(KERN_ERR, &card->dev->dev,
                "Multi-bit EDC error\n");

        dev_printk(KERN_ERR, &card->dev->dev,
            "Fault Address 0x%02x%08x, Fault Data 0x%08x%08x\n",
            addr_log2, addr_log1, data_log2, data_log1);
        dev_printk(KERN_ERR, &card->dev->dev,
            "Fault Check 0x%02x, Fault Syndrome 0x%02x\n",
            check, syndrome);

        writeb(0, card->csr_remap + ERROR_COUNT);
    }

    if (dma_status & DMASCR_PARITY_ERR_REP) {
        dev_printk(KERN_ERR, &card->dev->dev,
            "PARITY ERROR REPORTED\n");
        pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
        pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
    }

    if (dma_status & DMASCR_PARITY_ERR_DET) {
        dev_printk(KERN_ERR, &card->dev->dev,
            "PARITY ERROR DETECTED\n");
        pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
        pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
    }

    if (dma_status & DMASCR_SYSTEM_ERR_SIG) {
        dev_printk(KERN_ERR, &card->dev->dev, "SYSTEM ERROR\n");
        pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
        pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
    }

    if (dma_status & DMASCR_TARGET_ABT) {
        dev_printk(KERN_ERR, &card->dev->dev, "TARGET ABORT\n");
        pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
        pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
    }

    if (dma_status & DMASCR_MASTER_ABT) {
        dev_printk(KERN_ERR, &card->dev->dev, "MASTER ABORT\n");
        pci_read_config_word(card->dev, PCI_STATUS, &cfg_status);
        pci_write_config_word(card->dev, PCI_STATUS, cfg_status);
    }

    /* and process the DMA descriptors */
    card->dma_status = dma_status;
    tasklet_schedule(&card->tasklet);

HW_TRACE(0x36);

    return IRQ_HANDLED;
}

/*
 * If both batteries are good, no LED
 * If either battery has been warned, solid LED
 * If both batteries are bad, flash the LED quickly
 * If either battery is bad, flash the LED semi quickly
 */
static void set_fault_to_battery_status(struct cardinfo *card)
{
    if (card->battery[0].good && card->battery[1].good)
        set_led(card, LED_FAULT, LED_OFF);
    else if (card->battery[0].warned || card->battery[1].warned)
        set_led(card, LED_FAULT, LED_ON);
    else if (!card->battery[0].good && !card->battery[1].good)
        set_led(card, LED_FAULT, LED_FLASH_7_0);
    else
        set_led(card, LED_FAULT, LED_FLASH_3_5);
}

static void init_battery_timer(void);

static int check_battery(struct cardinfo *card, int battery, int status)
{
    if (status != card->battery[battery].good) {
        card->battery[battery].good = !card->battery[battery].good;
        card->battery[battery].last_change = jiffies;

        if (card->battery[battery].good) {
            dev_printk(KERN_ERR, &card->dev->dev,
                "Battery %d now good\n", battery + 1);
            card->battery[battery].warned = 0;
        } else
            dev_printk(KERN_ERR, &card->dev->dev,
                "Battery %d now FAILED\n", battery + 1);

        return 1;
    } else if (!card->battery[battery].good &&
           !card->battery[battery].warned &&
           time_after_eq(jiffies, card->battery[battery].last_change +
                 (HZ * 60 * 60 * 5))) {
        dev_printk(KERN_ERR, &card->dev->dev,
            "Battery %d still FAILED after 5 hours\n", battery + 1);
        card->battery[battery].warned = 1;

        return 1;
    }

    return 0;
}

static void check_batteries(struct cardinfo *card)
{
    /* NOTE: this must *never* be called while the card
     * is doing (bus-to-card) DMA, or you will need the
     * reset switch
     */
    unsigned char status;
    int ret1, ret2;

    status = readb(card->csr_remap + MEMCTRLSTATUS_BATTERY);
    if (debug & DEBUG_BATTERY_POLLING)
        dev_printk(KERN_DEBUG, &card->dev->dev,
            "checking battery status, 1 = %s, 2 = %s\n",
               (status & BATTERY_1_FAILURE) ? "FAILURE" : "OK",
               (status & BATTERY_2_FAILURE) ? "FAILURE" : "OK");

    ret1 = check_battery(card, 0, !(status & BATTERY_1_FAILURE));
    ret2 = check_battery(card, 1, !(status & BATTERY_2_FAILURE));

    if (ret1 || ret2)
        set_fault_to_battery_status(card);
}

static void check_all_batteries(unsigned long ptr)
{
    int i;

    for (i = 0; i < num_cards; i++)
        if (!(cards[i].flags & UM_FLAG_NO_BATT)) {
            struct cardinfo *card = &cards[i];
            spin_lock_bh(&card->lock);
            if (card->Active >= 0)
                card->check_batteries = 1;
            else
                check_batteries(card);
            spin_unlock_bh(&card->lock);
        }

    init_battery_timer();
}

static void init_battery_timer(void)
{
    init_timer(&battery_timer);
    battery_timer.function = check_all_batteries;
    battery_timer.expires = jiffies + (HZ * 60);
    add_timer(&battery_timer);
}

static void del_battery_timer(void)
{
    del_timer(&battery_timer);
}

/*
 * Note no locks taken out here.  In a worst case scenario, we could drop
 * a chunk of system memory.  But that should never happen, since validation
 * happens at open or mount time, when locks are held.
 *
 *  That's crap, since doing that while some partitions are opened
 * or mounted will give you really nasty results.
 */
static int mm_revalidate(struct gendisk *disk)
{
    struct cardinfo *card = disk->private_data;
    set_capacity(disk, card->mm_size << 1);
    return 0;
}

static int mm_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
    struct cardinfo *card = bdev->bd_disk->private_data;
    int size = card->mm_size * (1024 / MM_HARDSECT);

    /*
     * get geometry: we have to fake one...  trim the size to a
     * multiple of 2048 (1M): tell we have 32 sectors, 64 heads,
     * whatever cylinders.
     */
    geo->heads     = 64;
    geo->sectors   = 32;
    geo->cylinders = size / (geo->heads * geo->sectors);
    return 0;
}

static const struct block_device_operations mm_fops = {
    .owner      = THIS_MODULE,
    .getgeo     = mm_getgeo,
    .revalidate_disk = mm_revalidate,
};

static int __devinit mm_pci_probe(struct pci_dev *dev,
                const struct pci_device_id *id)
{
    int ret = -ENODEV;
    struct cardinfo *card = &cards[num_cards];
    unsigned char   mem_present;
    unsigned char   batt_status;
    unsigned int    saved_bar, data;
    unsigned long   csr_base;
    unsigned long   csr_len;
    int     magic_number;
    static int  printed_version;

    if (!printed_version++)
        printk(KERN_INFO DRIVER_VERSION " : " DRIVER_DESC "\n");

    ret = pci_enable_device(dev);
    if (ret)
        return ret;

    pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0xF8);
    pci_set_master(dev);

    card->dev         = dev;

    csr_base = pci_resource_start(dev, 0);
    csr_len  = pci_resource_len(dev, 0);
    if (!csr_base || !csr_len)
        return -ENODEV;

    dev_printk(KERN_INFO, &dev->dev,
      "Micro Memory(tm) controller found (PCI Mem Module (Battery Backup))\n");

    if (pci_set_dma_mask(dev, DMA_BIT_MASK(64)) &&
        pci_set_dma_mask(dev, DMA_BIT_MASK(32))) {
        dev_printk(KERN_WARNING, &dev->dev, "NO suitable DMA found\n");
        return  -ENOMEM;
    }

    ret = pci_request_regions(dev, DRIVER_NAME);
    if (ret) {
        dev_printk(KERN_ERR, &card->dev->dev,
            "Unable to request memory region\n");
        goto failed_req_csr;
    }

    card->csr_remap = ioremap_nocache(csr_base, csr_len);
    if (!card->csr_remap) {
        dev_printk(KERN_ERR, &card->dev->dev,
            "Unable to remap memory region\n");
        ret = -ENOMEM;

        goto failed_remap_csr;
    }

    dev_printk(KERN_INFO, &card->dev->dev,
        "CSR 0x%08lx -> 0x%p (0x%lx)\n",
           csr_base, card->csr_remap, csr_len);

    switch (card->dev->device) {
    case 0x5415:
        card->flags |= UM_FLAG_NO_BYTE_STATUS | UM_FLAG_NO_BATTREG;
        magic_number = 0x59;
        break;

    case 0x5425:
        card->flags |= UM_FLAG_NO_BYTE_STATUS;
        magic_number = 0x5C;
        break;

    case 0x6155:
        card->flags |= UM_FLAG_NO_BYTE_STATUS |
                UM_FLAG_NO_BATTREG | UM_FLAG_NO_BATT;
        magic_number = 0x99;
        break;

    default:
        magic_number = 0x100;
        break;
    }

    if (readb(card->csr_remap + MEMCTRLSTATUS_MAGIC) != magic_number) {
        dev_printk(KERN_ERR, &card->dev->dev, "Magic number invalid\n");
        ret = -ENOMEM;
        goto failed_magic;
    }

    card->mm_pages[0].desc = pci_alloc_consistent(card->dev,
                        PAGE_SIZE * 2,
                        &card->mm_pages[0].page_dma);
    card->mm_pages[1].desc = pci_alloc_consistent(card->dev,
                        PAGE_SIZE * 2,
                        &card->mm_pages[1].page_dma);
    if (card->mm_pages[0].desc == NULL ||
        card->mm_pages[1].desc == NULL) {
        dev_printk(KERN_ERR, &card->dev->dev, "alloc failed\n");
        goto failed_alloc;
    }
    reset_page(&card->mm_pages[0]);
    reset_page(&card->mm_pages[1]);
    card->Ready = 0;    /* page 0 is ready */
    card->Active = -1;  /* no page is active */
    card->bio = NULL;
    card->biotail = &card->bio;

    card->queue = blk_alloc_queue(GFP_KERNEL);
    if (!card->queue)
        goto failed_alloc;

    blk_queue_make_request(card->queue, mm_make_request);
    card->queue->queue_lock = &card->lock;
    card->queue->queuedata = card;

    tasklet_init(&card->tasklet, process_page, (unsigned long)card);

    card->check_batteries = 0;

    mem_present = readb(card->csr_remap + MEMCTRLSTATUS_MEMORY);
    switch (mem_present) {
    case MEM_128_MB:
        card->mm_size = 1024 * 128;
        break;
    case MEM_256_MB:
        card->mm_size = 1024 * 256;
        break;
    case MEM_512_MB:
        card->mm_size = 1024 * 512;
        break;
    case MEM_1_GB:
        card->mm_size = 1024 * 1024;
        break;
    case MEM_2_GB:
        card->mm_size = 1024 * 2048;
        break;
    default:
        card->mm_size = 0;
        break;
    }

    /* Clear the LED's we control */
    set_led(card, LED_REMOVE, LED_OFF);
    set_led(card, LED_FAULT, LED_OFF);

    batt_status = readb(card->csr_remap + MEMCTRLSTATUS_BATTERY);

    card->battery[0].good = !(batt_status & BATTERY_1_FAILURE);
    card->battery[1].good = !(batt_status & BATTERY_2_FAILURE);
    card->battery[0].last_change = card->battery[1].last_change = jiffies;

    if (card->flags & UM_FLAG_NO_BATT)
        dev_printk(KERN_INFO, &card->dev->dev,
            "Size %d KB\n", card->mm_size);
    else {
        dev_printk(KERN_INFO, &card->dev->dev,
            "Size %d KB, Battery 1 %s (%s), Battery 2 %s (%s)\n",
               card->mm_size,
               batt_status & BATTERY_1_DISABLED ? "Disabled" : "Enabled",
               card->battery[0].good ? "OK" : "FAILURE",
               batt_status & BATTERY_2_DISABLED ? "Disabled" : "Enabled",
               card->battery[1].good ? "OK" : "FAILURE");

        set_fault_to_battery_status(card);
    }

    pci_read_config_dword(dev, PCI_BASE_ADDRESS_1, &saved_bar);
    data = 0xffffffff;
    pci_write_config_dword(dev, PCI_BASE_ADDRESS_1, data);
    pci_read_config_dword(dev, PCI_BASE_ADDRESS_1, &data);
    pci_write_config_dword(dev, PCI_BASE_ADDRESS_1, saved_bar);
    data &= 0xfffffff0;
    data = ~data;
    data += 1;

    if (request_irq(dev->irq, mm_interrupt, IRQF_SHARED, DRIVER_NAME,
            card)) {
        dev_printk(KERN_ERR, &card->dev->dev,
            "Unable to allocate IRQ\n");
        ret = -ENODEV;
        goto failed_req_irq;
    }

    dev_printk(KERN_INFO, &card->dev->dev,
        "Window size %d bytes, IRQ %d\n", data, dev->irq);

    spin_lock_init(&card->lock);

    pci_set_drvdata(dev, card);

    if (pci_write_cmd != 0x0F)  /* If not Memory Write & Invalidate */
        pci_write_cmd = 0x07;   /* then Memory Write command */

    if (pci_write_cmd & 0x08) { /* use Memory Write and Invalidate */
        unsigned short cfg_command;
        pci_read_config_word(dev, PCI_COMMAND, &cfg_command);
        cfg_command |= 0x10; /* Memory Write & Invalidate Enable */
        pci_write_config_word(dev, PCI_COMMAND, cfg_command);
    }
    pci_cmds = (pci_read_cmd << 28) | (pci_write_cmd << 24);

    num_cards++;

    if (!get_userbit(card, MEMORY_INITIALIZED)) {
        dev_printk(KERN_INFO, &card->dev->dev,
          "memory NOT initialized. Consider over-writing whole device.\n");
        card->init_size = 0;
    } else {
        dev_printk(KERN_INFO, &card->dev->dev,
            "memory already initialized\n");
        card->init_size = card->mm_size;
    }

    /* Enable ECC */
    writeb(EDC_STORE_CORRECT, card->csr_remap + MEMCTRLCMD_ERRCTRL);

    return 0;

 failed_req_irq:
 failed_alloc:
    if (card->mm_pages[0].desc)
        pci_free_consistent(card->dev, PAGE_SIZE*2,
                    card->mm_pages[0].desc,
                    card->mm_pages[0].page_dma);
    if (card->mm_pages[1].desc)
        pci_free_consistent(card->dev, PAGE_SIZE*2,
                    card->mm_pages[1].desc,
                    card->mm_pages[1].page_dma);
 failed_magic:
    iounmap(card->csr_remap);
 failed_remap_csr:
    pci_release_regions(dev);
 failed_req_csr:

    return ret;
}

static void mm_pci_remove(struct pci_dev *dev)
{
    struct cardinfo *card = pci_get_drvdata(dev);

    tasklet_kill(&card->tasklet);
    free_irq(dev->irq, card);
    iounmap(card->csr_remap);

    if (card->mm_pages[0].desc)
        pci_free_consistent(card->dev, PAGE_SIZE*2,
                    card->mm_pages[0].desc,
                    card->mm_pages[0].page_dma);
    if (card->mm_pages[1].desc)
        pci_free_consistent(card->dev, PAGE_SIZE*2,
                    card->mm_pages[1].desc,
                    card->mm_pages[1].page_dma);
    blk_cleanup_queue(card->queue);

    pci_release_regions(dev);
    pci_disable_device(dev);
}

static const struct pci_device_id mm_pci_ids[] = {
    {PCI_DEVICE(PCI_VENDOR_ID_MICRO_MEMORY, PCI_DEVICE_ID_MICRO_MEMORY_5415CN)},
    {PCI_DEVICE(PCI_VENDOR_ID_MICRO_MEMORY, PCI_DEVICE_ID_MICRO_MEMORY_5425CN)},
    {PCI_DEVICE(PCI_VENDOR_ID_MICRO_MEMORY, PCI_DEVICE_ID_MICRO_MEMORY_6155)},
    {
    .vendor =   0x8086,
    .device =   0xB555,
    .subvendor =    0x1332,
    .subdevice =    0x5460,
    .class =    0x050000,
    .class_mask =   0,
    }, { /* end: all zeroes */ }
};

MODULE_DEVICE_TABLE(pci, mm_pci_ids);

static struct pci_driver mm_pci_driver = {
    .name       = DRIVER_NAME,
    .id_table   = mm_pci_ids,
    .probe      = mm_pci_probe,
    .remove     = mm_pci_remove,
};

static int __init mm_init(void)
{
    int retval, i;
    int err;

    retval = pci_register_driver(&mm_pci_driver);
    if (retval)
        return -ENOMEM;

    err = major_nr = register_blkdev(0, DRIVER_NAME);
    if (err < 0) {
        pci_unregister_driver(&mm_pci_driver);
        return -EIO;
    }

    for (i = 0; i < num_cards; i++) {
        mm_gendisk[i] = alloc_disk(1 << MM_SHIFT);
        if (!mm_gendisk[i])
            goto out;
    }

    for (i = 0; i < num_cards; i++) {
        struct gendisk *disk = mm_gendisk[i];
        sprintf(disk->disk_name, "umem%c", 'a'+i);
        spin_lock_init(&cards[i].lock);
        disk->major = major_nr;
        disk->first_minor  = i << MM_SHIFT;
        disk->fops = &mm_fops;
        disk->private_data = &cards[i];
        disk->queue = cards[i].queue;
        set_capacity(disk, cards[i].mm_size << 1);
        add_disk(disk);
    }

    init_battery_timer();
    printk(KERN_INFO "MM: desc_per_page = %ld\n", DESC_PER_PAGE);
/* printk("mm_init: Done. 10-19-01 9:00\n"); */
    return 0;

out:
    pci_unregister_driver(&mm_pci_driver);
    unregister_blkdev(major_nr, DRIVER_NAME);
    while (i--)
        put_disk(mm_gendisk[i]);
    return -ENOMEM;
}

static void __exit mm_cleanup(void)
{
    int i;

    del_battery_timer();

    for (i = 0; i < num_cards ; i++) {
        del_gendisk(mm_gendisk[i]);
        put_disk(mm_gendisk[i]);
    }

    pci_unregister_driver(&mm_pci_driver);

    unregister_blkdev(major_nr, DRIVER_NAME);
}

module_init(mm_init);
module_exit(mm_cleanup);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");