hpilo.c

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/*
 * Driver for the HP iLO management processor.
 *
 * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
 *  David Altobelli <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/file.h>
#include <linux/cdev.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include "hpilo.h"

static struct class *ilo_class;
static unsigned int ilo_major;
static unsigned int max_ccb = MIN_CCB;
static char ilo_hwdev[MAX_ILO_DEV];

static inline int get_entry_id(int entry)
{
    return (entry & ENTRY_MASK_DESCRIPTOR) >> ENTRY_BITPOS_DESCRIPTOR;
}

static inline int get_entry_len(int entry)
{
    return ((entry & ENTRY_MASK_QWORDS) >> ENTRY_BITPOS_QWORDS) << 3;
}

static inline int mk_entry(int id, int len)
{
    int qlen = len & 7 ? (len >> 3) + 1 : len >> 3;
    return id << ENTRY_BITPOS_DESCRIPTOR | qlen << ENTRY_BITPOS_QWORDS;
}

static inline int desc_mem_sz(int nr_entry)
{
    return nr_entry << L2_QENTRY_SZ;
}

/*
 * FIFO queues, shared with hardware.
 *
 * If a queue has empty slots, an entry is added to the queue tail,
 * and that entry is marked as occupied.
 * Entries can be dequeued from the head of the list, when the device
 * has marked the entry as consumed.
 *
 * Returns true on successful queue/dequeue, false on failure.
 */
static int fifo_enqueue(struct ilo_hwinfo *hw, char *fifobar, int entry)
{
    struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
    unsigned long flags;
    int ret = 0;

    spin_lock_irqsave(&hw->fifo_lock, flags);
    if (!(fifo_q->fifobar[(fifo_q->tail + 1) & fifo_q->imask]
          & ENTRY_MASK_O)) {
        fifo_q->fifobar[fifo_q->tail & fifo_q->imask] |=
                (entry & ENTRY_MASK_NOSTATE) | fifo_q->merge;
        fifo_q->tail += 1;
        ret = 1;
    }
    spin_unlock_irqrestore(&hw->fifo_lock, flags);

    return ret;
}

static int fifo_dequeue(struct ilo_hwinfo *hw, char *fifobar, int *entry)
{
    struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
    unsigned long flags;
    int ret = 0;
    u64 c;

    spin_lock_irqsave(&hw->fifo_lock, flags);
    c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
    if (c & ENTRY_MASK_C) {
        if (entry)
            *entry = c & ENTRY_MASK_NOSTATE;

        fifo_q->fifobar[fifo_q->head & fifo_q->imask] =
                            (c | ENTRY_MASK) + 1;
        fifo_q->head += 1;
        ret = 1;
    }
    spin_unlock_irqrestore(&hw->fifo_lock, flags);

    return ret;
}

static int fifo_check_recv(struct ilo_hwinfo *hw, char *fifobar)
{
    struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
    unsigned long flags;
    int ret = 0;
    u64 c;

    spin_lock_irqsave(&hw->fifo_lock, flags);
    c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
    if (c & ENTRY_MASK_C)
        ret = 1;
    spin_unlock_irqrestore(&hw->fifo_lock, flags);

    return ret;
}

static int ilo_pkt_enqueue(struct ilo_hwinfo *hw, struct ccb *ccb,
               int dir, int id, int len)
{
    char *fifobar;
    int entry;

    if (dir == SENDQ)
        fifobar = ccb->ccb_u1.send_fifobar;
    else
        fifobar = ccb->ccb_u3.recv_fifobar;

    entry = mk_entry(id, len);
    return fifo_enqueue(hw, fifobar, entry);
}

static int ilo_pkt_dequeue(struct ilo_hwinfo *hw, struct ccb *ccb,
               int dir, int *id, int *len, void **pkt)
{
    char *fifobar, *desc;
    int entry = 0, pkt_id = 0;
    int ret;

    if (dir == SENDQ) {
        fifobar = ccb->ccb_u1.send_fifobar;
        desc = ccb->ccb_u2.send_desc;
    } else {
        fifobar = ccb->ccb_u3.recv_fifobar;
        desc = ccb->ccb_u4.recv_desc;
    }

    ret = fifo_dequeue(hw, fifobar, &entry);
    if (ret) {
        pkt_id = get_entry_id(entry);
        if (id)
            *id = pkt_id;
        if (len)
            *len = get_entry_len(entry);
        if (pkt)
            *pkt = (void *)(desc + desc_mem_sz(pkt_id));
    }

    return ret;
}

static int ilo_pkt_recv(struct ilo_hwinfo *hw, struct ccb *ccb)
{
    char *fifobar = ccb->ccb_u3.recv_fifobar;

    return fifo_check_recv(hw, fifobar);
}

static inline void doorbell_set(struct ccb *ccb)
{
    iowrite8(1, ccb->ccb_u5.db_base);
}

static inline void doorbell_clr(struct ccb *ccb)
{
    iowrite8(2, ccb->ccb_u5.db_base);
}

static inline int ctrl_set(int l2sz, int idxmask, int desclim)
{
    int active = 0, go = 1;
    return l2sz << CTRL_BITPOS_L2SZ |
           idxmask << CTRL_BITPOS_FIFOINDEXMASK |
           desclim << CTRL_BITPOS_DESCLIMIT |
           active << CTRL_BITPOS_A |
           go << CTRL_BITPOS_G;
}

static void ctrl_setup(struct ccb *ccb, int nr_desc, int l2desc_sz)
{
    /* for simplicity, use the same parameters for send and recv ctrls */
    ccb->send_ctrl = ctrl_set(l2desc_sz, nr_desc-1, nr_desc-1);
    ccb->recv_ctrl = ctrl_set(l2desc_sz, nr_desc-1, nr_desc-1);
}

static inline int fifo_sz(int nr_entry)
{
    /* size of a fifo is determined by the number of entries it contains */
    return (nr_entry * sizeof(u64)) + FIFOHANDLESIZE;
}

static void fifo_setup(void *base_addr, int nr_entry)
{
    struct fifo *fifo_q = base_addr;
    int i;

    /* set up an empty fifo */
    fifo_q->head = 0;
    fifo_q->tail = 0;
    fifo_q->reset = 0;
    fifo_q->nrents = nr_entry;
    fifo_q->imask = nr_entry - 1;
    fifo_q->merge = ENTRY_MASK_O;

    for (i = 0; i < nr_entry; i++)
        fifo_q->fifobar[i] = 0;
}

static void ilo_ccb_close(struct pci_dev *pdev, struct ccb_data *data)
{
    struct ccb *driver_ccb = &data->driver_ccb;
    struct ccb __iomem *device_ccb = data->mapped_ccb;
    int retries;

    /* complicated dance to tell the hw we are stopping */
    doorbell_clr(driver_ccb);
    iowrite32(ioread32(&device_ccb->send_ctrl) & ~(1 << CTRL_BITPOS_G),
          &device_ccb->send_ctrl);
    iowrite32(ioread32(&device_ccb->recv_ctrl) & ~(1 << CTRL_BITPOS_G),
          &device_ccb->recv_ctrl);

    /* give iLO some time to process stop request */
    for (retries = MAX_WAIT; retries > 0; retries--) {
        doorbell_set(driver_ccb);
        udelay(WAIT_TIME);
        if (!(ioread32(&device_ccb->send_ctrl) & (1 << CTRL_BITPOS_A))
            &&
            !(ioread32(&device_ccb->recv_ctrl) & (1 << CTRL_BITPOS_A)))
            break;
    }
    if (retries == 0)
        dev_err(&pdev->dev, "Closing, but controller still active\n");

    /* clear the hw ccb */
    memset_io(device_ccb, 0, sizeof(struct ccb));

    /* free resources used to back send/recv queues */
    pci_free_consistent(pdev, data->dma_size, data->dma_va, data->dma_pa);
}

static int ilo_ccb_setup(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
{
    char *dma_va;
    dma_addr_t dma_pa;
    struct ccb *driver_ccb, *ilo_ccb;

    driver_ccb = &data->driver_ccb;
    ilo_ccb = &data->ilo_ccb;

    data->dma_size = 2 * fifo_sz(NR_QENTRY) +
             2 * desc_mem_sz(NR_QENTRY) +
             ILO_START_ALIGN + ILO_CACHE_SZ;

    data->dma_va = pci_alloc_consistent(hw->ilo_dev, data->dma_size,
                        &data->dma_pa);
    if (!data->dma_va)
        return -ENOMEM;

    dma_va = (char *)data->dma_va;
    dma_pa = data->dma_pa;

    memset(dma_va, 0, data->dma_size);

    dma_va = (char *)roundup((unsigned long)dma_va, ILO_START_ALIGN);
    dma_pa = roundup(dma_pa, ILO_START_ALIGN);

    /*
     * Create two ccb's, one with virt addrs, one with phys addrs.
     * Copy the phys addr ccb to device shared mem.
     */
    ctrl_setup(driver_ccb, NR_QENTRY, L2_QENTRY_SZ);
    ctrl_setup(ilo_ccb, NR_QENTRY, L2_QENTRY_SZ);

    fifo_setup(dma_va, NR_QENTRY);
    driver_ccb->ccb_u1.send_fifobar = dma_va + FIFOHANDLESIZE;
    ilo_ccb->ccb_u1.send_fifobar_pa = dma_pa + FIFOHANDLESIZE;
    dma_va += fifo_sz(NR_QENTRY);
    dma_pa += fifo_sz(NR_QENTRY);

    dma_va = (char *)roundup((unsigned long)dma_va, ILO_CACHE_SZ);
    dma_pa = roundup(dma_pa, ILO_CACHE_SZ);

    fifo_setup(dma_va, NR_QENTRY);
    driver_ccb->ccb_u3.recv_fifobar = dma_va + FIFOHANDLESIZE;
    ilo_ccb->ccb_u3.recv_fifobar_pa = dma_pa + FIFOHANDLESIZE;
    dma_va += fifo_sz(NR_QENTRY);
    dma_pa += fifo_sz(NR_QENTRY);

    driver_ccb->ccb_u2.send_desc = dma_va;
    ilo_ccb->ccb_u2.send_desc_pa = dma_pa;
    dma_pa += desc_mem_sz(NR_QENTRY);
    dma_va += desc_mem_sz(NR_QENTRY);

    driver_ccb->ccb_u4.recv_desc = dma_va;
    ilo_ccb->ccb_u4.recv_desc_pa = dma_pa;

    driver_ccb->channel = slot;
    ilo_ccb->channel = slot;

    driver_ccb->ccb_u5.db_base = hw->db_vaddr + (slot << L2_DB_SIZE);
    ilo_ccb->ccb_u5.db_base = NULL; /* hw ccb's doorbell is not used */

    return 0;
}

static void ilo_ccb_open(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
{
    int pkt_id, pkt_sz;
    struct ccb *driver_ccb = &data->driver_ccb;

    /* copy the ccb with physical addrs to device memory */
    data->mapped_ccb = (struct ccb __iomem *)
                (hw->ram_vaddr + (slot * ILOHW_CCB_SZ));
    memcpy_toio(data->mapped_ccb, &data->ilo_ccb, sizeof(struct ccb));

    /* put packets on the send and receive queues */
    pkt_sz = 0;
    for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++) {
        ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, pkt_sz);
        doorbell_set(driver_ccb);
    }

    pkt_sz = desc_mem_sz(1);
    for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++)
        ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, pkt_sz);

    /* the ccb is ready to use */
    doorbell_clr(driver_ccb);
}

static int ilo_ccb_verify(struct ilo_hwinfo *hw, struct ccb_data *data)
{
    int pkt_id, i;
    struct ccb *driver_ccb = &data->driver_ccb;

    /* make sure iLO is really handling requests */
    for (i = MAX_WAIT; i > 0; i--) {
        if (ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, NULL, NULL))
            break;
        udelay(WAIT_TIME);
    }

    if (i == 0) {
        dev_err(&hw->ilo_dev->dev, "Open could not dequeue a packet\n");
        return -EBUSY;
    }

    ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, 0);
    doorbell_set(driver_ccb);
    return 0;
}

static inline int is_channel_reset(struct ccb *ccb)
{
    /* check for this particular channel needing a reset */
    return FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset;
}

static inline void set_channel_reset(struct ccb *ccb)
{
    /* set a flag indicating this channel needs a reset */
    FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset = 1;
}

static inline int get_device_outbound(struct ilo_hwinfo *hw)
{
    return ioread32(&hw->mmio_vaddr[DB_OUT]);
}

static inline int is_db_reset(int db_out)
{
    return db_out & (1 << DB_RESET);
}

static inline int is_device_reset(struct ilo_hwinfo *hw)
{
    /* check for global reset condition */
    return is_db_reset(get_device_outbound(hw));
}

static inline void clear_pending_db(struct ilo_hwinfo *hw, int clr)
{
    iowrite32(clr, &hw->mmio_vaddr[DB_OUT]);
}

static inline void clear_device(struct ilo_hwinfo *hw)
{
    /* clear the device (reset bits, pending channel entries) */
    clear_pending_db(hw, -1);
}

static inline void ilo_enable_interrupts(struct ilo_hwinfo *hw)
{
    iowrite8(ioread8(&hw->mmio_vaddr[DB_IRQ]) | 1, &hw->mmio_vaddr[DB_IRQ]);
}

static inline void ilo_disable_interrupts(struct ilo_hwinfo *hw)
{
    iowrite8(ioread8(&hw->mmio_vaddr[DB_IRQ]) & ~1,
         &hw->mmio_vaddr[DB_IRQ]);
}

static void ilo_set_reset(struct ilo_hwinfo *hw)
{
    int slot;

    /*
     * Mapped memory is zeroed on ilo reset, so set a per ccb flag
     * to indicate that this ccb needs to be closed and reopened.
     */
    for (slot = 0; slot < max_ccb; slot++) {
        if (!hw->ccb_alloc[slot])
            continue;
        set_channel_reset(&hw->ccb_alloc[slot]->driver_ccb);
    }
}

static ssize_t ilo_read(struct file *fp, char __user *buf,
            size_t len, loff_t *off)
{
    int err, found, cnt, pkt_id, pkt_len;
    struct ccb_data *data = fp->private_data;
    struct ccb *driver_ccb = &data->driver_ccb;
    struct ilo_hwinfo *hw = data->ilo_hw;
    void *pkt;

    if (is_channel_reset(driver_ccb)) {
        /*
         * If the device has been reset, applications
         * need to close and reopen all ccbs.
         */
        return -ENODEV;
    }

    /*
     * This function is to be called when data is expected
     * in the channel, and will return an error if no packet is found
     * during the loop below.  The sleep/retry logic is to allow
     * applications to call read() immediately post write(),
     * and give iLO some time to process the sent packet.
     */
    cnt = 20;
    do {
        /* look for a received packet */
        found = ilo_pkt_dequeue(hw, driver_ccb, RECVQ, &pkt_id,
                    &pkt_len, &pkt);
        if (found)
            break;
        cnt--;
        msleep(100);
    } while (!found && cnt);

    if (!found)
        return -EAGAIN;

    /* only copy the length of the received packet */
    if (pkt_len < len)
        len = pkt_len;

    err = copy_to_user(buf, pkt, len);

    /* return the received packet to the queue */
    ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, desc_mem_sz(1));

    return err ? -EFAULT : len;
}

static ssize_t ilo_write(struct file *fp, const char __user *buf,
             size_t len, loff_t *off)
{
    int err, pkt_id, pkt_len;
    struct ccb_data *data = fp->private_data;
    struct ccb *driver_ccb = &data->driver_ccb;
    struct ilo_hwinfo *hw = data->ilo_hw;
    void *pkt;

    if (is_channel_reset(driver_ccb))
        return -ENODEV;

    /* get a packet to send the user command */
    if (!ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, &pkt_len, &pkt))
        return -EBUSY;

    /* limit the length to the length of the packet */
    if (pkt_len < len)
        len = pkt_len;

    /* on failure, set the len to 0 to return empty packet to the device */
    err = copy_from_user(pkt, buf, len);
    if (err)
        len = 0;

    /* send the packet */
    ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, len);
    doorbell_set(driver_ccb);

    return err ? -EFAULT : len;
}

static unsigned int ilo_poll(struct file *fp, poll_table *wait)
{
    struct ccb_data *data = fp->private_data;
    struct ccb *driver_ccb = &data->driver_ccb;

    poll_wait(fp, &data->ccb_waitq, wait);

    if (is_channel_reset(driver_ccb))
        return POLLERR;
    else if (ilo_pkt_recv(data->ilo_hw, driver_ccb))
        return POLLIN | POLLRDNORM;

    return 0;
}

static int ilo_close(struct inode *ip, struct file *fp)
{
    int slot;
    struct ccb_data *data;
    struct ilo_hwinfo *hw;
    unsigned long flags;

    slot = iminor(ip) % max_ccb;
    hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);

    spin_lock(&hw->open_lock);

    if (hw->ccb_alloc[slot]->ccb_cnt == 1) {

        data = fp->private_data;

        spin_lock_irqsave(&hw->alloc_lock, flags);
        hw->ccb_alloc[slot] = NULL;
        spin_unlock_irqrestore(&hw->alloc_lock, flags);

        ilo_ccb_close(hw->ilo_dev, data);

        kfree(data);
    } else
        hw->ccb_alloc[slot]->ccb_cnt--;

    spin_unlock(&hw->open_lock);

    return 0;
}

static int ilo_open(struct inode *ip, struct file *fp)
{
    int slot, error;
    struct ccb_data *data;
    struct ilo_hwinfo *hw;
    unsigned long flags;

    slot = iminor(ip) % max_ccb;
    hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);

    /* new ccb allocation */
    data = kzalloc(sizeof(*data), GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    spin_lock(&hw->open_lock);

    /* each fd private_data holds sw/hw view of ccb */
    if (hw->ccb_alloc[slot] == NULL) {
        /* create a channel control block for this minor */
        error = ilo_ccb_setup(hw, data, slot);
        if (error) {
            kfree(data);
            goto out;
        }

        data->ccb_cnt = 1;
        data->ccb_excl = fp->f_flags & O_EXCL;
        data->ilo_hw = hw;
        init_waitqueue_head(&data->ccb_waitq);

        /* write the ccb to hw */
        spin_lock_irqsave(&hw->alloc_lock, flags);
        ilo_ccb_open(hw, data, slot);
        hw->ccb_alloc[slot] = data;
        spin_unlock_irqrestore(&hw->alloc_lock, flags);

        /* make sure the channel is functional */
        error = ilo_ccb_verify(hw, data);
        if (error) {

            spin_lock_irqsave(&hw->alloc_lock, flags);
            hw->ccb_alloc[slot] = NULL;
            spin_unlock_irqrestore(&hw->alloc_lock, flags);

            ilo_ccb_close(hw->ilo_dev, data);

            kfree(data);
            goto out;
        }

    } else {
        kfree(data);
        if (fp->f_flags & O_EXCL || hw->ccb_alloc[slot]->ccb_excl) {
            /*
             * The channel exists, and either this open
             * or a previous open of this channel wants
             * exclusive access.
             */
            error = -EBUSY;
        } else {
            hw->ccb_alloc[slot]->ccb_cnt++;
            error = 0;
        }
    }
out:
    spin_unlock(&hw->open_lock);

    if (!error)
        fp->private_data = hw->ccb_alloc[slot];

    return error;
}

static const struct file_operations ilo_fops = {
    .owner      = THIS_MODULE,
    .read       = ilo_read,
    .write      = ilo_write,
    .poll       = ilo_poll,
    .open       = ilo_open,
    .release    = ilo_close,
    .llseek     = noop_llseek,
};

static irqreturn_t ilo_isr(int irq, void *data)
{
    struct ilo_hwinfo *hw = data;
    int pending, i;

    spin_lock(&hw->alloc_lock);

    /* check for ccbs which have data */
    pending = get_device_outbound(hw);
    if (!pending) {
        spin_unlock(&hw->alloc_lock);
        return IRQ_NONE;
    }

    if (is_db_reset(pending)) {
        /* wake up all ccbs if the device was reset */
        pending = -1;
        ilo_set_reset(hw);
    }

    for (i = 0; i < max_ccb; i++) {
        if (!hw->ccb_alloc[i])
            continue;
        if (pending & (1 << i))
            wake_up_interruptible(&hw->ccb_alloc[i]->ccb_waitq);
    }

    /* clear the device of the channels that have been handled */
    clear_pending_db(hw, pending);

    spin_unlock(&hw->alloc_lock);

    return IRQ_HANDLED;
}

static void ilo_unmap_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
{
    pci_iounmap(pdev, hw->db_vaddr);
    pci_iounmap(pdev, hw->ram_vaddr);
    pci_iounmap(pdev, hw->mmio_vaddr);
}

static int __devinit ilo_map_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
{
    int error = -ENOMEM;

    /* map the memory mapped i/o registers */
    hw->mmio_vaddr = pci_iomap(pdev, 1, 0);
    if (hw->mmio_vaddr == NULL) {
        dev_err(&pdev->dev, "Error mapping mmio\n");
        goto out;
    }

    /* map the adapter shared memory region */
    hw->ram_vaddr = pci_iomap(pdev, 2, max_ccb * ILOHW_CCB_SZ);
    if (hw->ram_vaddr == NULL) {
        dev_err(&pdev->dev, "Error mapping shared mem\n");
        goto mmio_free;
    }

    /* map the doorbell aperture */
    hw->db_vaddr = pci_iomap(pdev, 3, max_ccb * ONE_DB_SIZE);
    if (hw->db_vaddr == NULL) {
        dev_err(&pdev->dev, "Error mapping doorbell\n");
        goto ram_free;
    }

    return 0;
ram_free:
    pci_iounmap(pdev, hw->ram_vaddr);
mmio_free:
    pci_iounmap(pdev, hw->mmio_vaddr);
out:
    return error;
}

static void ilo_remove(struct pci_dev *pdev)
{
    int i, minor;
    struct ilo_hwinfo *ilo_hw = pci_get_drvdata(pdev);

    clear_device(ilo_hw);

    minor = MINOR(ilo_hw->cdev.dev);
    for (i = minor; i < minor + max_ccb; i++)
        device_destroy(ilo_class, MKDEV(ilo_major, i));

    cdev_del(&ilo_hw->cdev);
    ilo_disable_interrupts(ilo_hw);
    free_irq(pdev->irq, ilo_hw);
    ilo_unmap_device(pdev, ilo_hw);
    pci_release_regions(pdev);
    /*
     * pci_disable_device(pdev) used to be here. But this PCI device has
     * two functions with interrupt lines connected to a single pin. The
     * other one is a USB host controller. So when we disable the PIN here
     * e.g. by rmmod hpilo, the controller stops working. It is because
     * the interrupt link is disabled in ACPI since it is not refcounted
     * yet. See acpi_pci_link_free_irq called from acpi_pci_irq_disable.
     */
    kfree(ilo_hw);
    ilo_hwdev[(minor / max_ccb)] = 0;
}

static int __devinit ilo_probe(struct pci_dev *pdev,
                   const struct pci_device_id *ent)
{
    int devnum, minor, start, error;
    struct ilo_hwinfo *ilo_hw;

    if (max_ccb > MAX_CCB)
        max_ccb = MAX_CCB;
    else if (max_ccb < MIN_CCB)
        max_ccb = MIN_CCB;

    /* find a free range for device files */
    for (devnum = 0; devnum < MAX_ILO_DEV; devnum++) {
        if (ilo_hwdev[devnum] == 0) {
            ilo_hwdev[devnum] = 1;
            break;
        }
    }

    if (devnum == MAX_ILO_DEV) {
        dev_err(&pdev->dev, "Error finding free device\n");
        return -ENODEV;
    }

    /* track global allocations for this device */
    error = -ENOMEM;
    ilo_hw = kzalloc(sizeof(*ilo_hw), GFP_KERNEL);
    if (!ilo_hw)
        goto out;

    ilo_hw->ilo_dev = pdev;
    spin_lock_init(&ilo_hw->alloc_lock);
    spin_lock_init(&ilo_hw->fifo_lock);
    spin_lock_init(&ilo_hw->open_lock);

    error = pci_enable_device(pdev);
    if (error)
        goto free;

    pci_set_master(pdev);

    error = pci_request_regions(pdev, ILO_NAME);
    if (error)
        goto disable;

    error = ilo_map_device(pdev, ilo_hw);
    if (error)
        goto free_regions;

    pci_set_drvdata(pdev, ilo_hw);
    clear_device(ilo_hw);

    error = request_irq(pdev->irq, ilo_isr, IRQF_SHARED, "hpilo", ilo_hw);
    if (error)
        goto unmap;

    ilo_enable_interrupts(ilo_hw);

    cdev_init(&ilo_hw->cdev, &ilo_fops);
    ilo_hw->cdev.owner = THIS_MODULE;
    start = devnum * max_ccb;
    error = cdev_add(&ilo_hw->cdev, MKDEV(ilo_major, start), max_ccb);
    if (error) {
        dev_err(&pdev->dev, "Could not add cdev\n");
        goto remove_isr;
    }

    for (minor = 0 ; minor < max_ccb; minor++) {
        struct device *dev;
        dev = device_create(ilo_class, &pdev->dev,
                    MKDEV(ilo_major, minor), NULL,
                    "hpilo!d%dccb%d", devnum, minor);
        if (IS_ERR(dev))
            dev_err(&pdev->dev, "Could not create files\n");
    }

    return 0;
remove_isr:
    ilo_disable_interrupts(ilo_hw);
    free_irq(pdev->irq, ilo_hw);
unmap:
    ilo_unmap_device(pdev, ilo_hw);
free_regions:
    pci_release_regions(pdev);
disable:
/*  pci_disable_device(pdev);  see comment in ilo_remove */
free:
    kfree(ilo_hw);
out:
    ilo_hwdev[devnum] = 0;
    return error;
}

static struct pci_device_id ilo_devices[] = {
    { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB204) },
    { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3307) },
    { }
};
MODULE_DEVICE_TABLE(pci, ilo_devices);

static struct pci_driver ilo_driver = {
    .name     = ILO_NAME,
    .id_table = ilo_devices,
    .probe    = ilo_probe,
    .remove   = __devexit_p(ilo_remove),
};

static int __init ilo_init(void)
{
    int error;
    dev_t dev;

    ilo_class = class_create(THIS_MODULE, "iLO");
    if (IS_ERR(ilo_class)) {
        error = PTR_ERR(ilo_class);
        goto out;
    }

    error = alloc_chrdev_region(&dev, 0, MAX_OPEN, ILO_NAME);
    if (error)
        goto class_destroy;

    ilo_major = MAJOR(dev);

    error = pci_register_driver(&ilo_driver);
    if (error)
        goto chr_remove;

    return 0;
chr_remove:
    unregister_chrdev_region(dev, MAX_OPEN);
class_destroy:
    class_destroy(ilo_class);
out:
    return error;
}

static void __exit ilo_exit(void)
{
    pci_unregister_driver(&ilo_driver);
    unregister_chrdev_region(MKDEV(ilo_major, 0), MAX_OPEN);
    class_destroy(ilo_class);
}

MODULE_VERSION("1.3");
MODULE_ALIAS(ILO_NAME);
MODULE_DESCRIPTION(ILO_NAME);
MODULE_AUTHOR("David Altobelli <[email protected]>");
MODULE_LICENSE("GPL v2");

module_param(max_ccb, uint, 0444);
MODULE_PARM_DESC(max_ccb, "Maximum number of HP iLO channels to attach (8)");

module_init(ilo_init);
module_exit(ilo_exit);