pci-sysfs.c

Go to the documentation of this file.

/*
 * drivers/pci/pci-sysfs.c
 *
 * (C) Copyright 2002-2004 Greg Kroah-Hartman <[email protected]>
 * (C) Copyright 2002-2004 IBM Corp.
 * (C) Copyright 2003 Matthew Wilcox
 * (C) Copyright 2003 Hewlett-Packard
 * (C) Copyright 2004 Jon Smirl <[email protected]>
 * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <[email protected]>
 *
 * File attributes for PCI devices
 *
 * Modeled after usb's driverfs.c 
 *
 */


#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/stat.h>
#include <linux/export.h>
#include <linux/topology.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/capability.h>
#include <linux/security.h>
#include <linux/pci-aspm.h>
#include <linux/slab.h>
#include <linux/vgaarb.h>
#include <linux/pm_runtime.h>
#include "pci.h"

static int sysfs_initialized;   /* = 0 */

/* show configuration fields */
#define pci_config_attr(field, format_string)               \
static ssize_t                              \
field##_show(struct device *dev, struct device_attribute *attr, char *buf)              \
{                                   \
    struct pci_dev *pdev;                       \
                                    \
    pdev = to_pci_dev (dev);                    \
    return sprintf (buf, format_string, pdev->field);       \
}

pci_config_attr(vendor, "0x%04x\n");
pci_config_attr(device, "0x%04x\n");
pci_config_attr(subsystem_vendor, "0x%04x\n");
pci_config_attr(subsystem_device, "0x%04x\n");
pci_config_attr(class, "0x%06x\n");
pci_config_attr(irq, "%u\n");

static ssize_t broken_parity_status_show(struct device *dev,
                     struct device_attribute *attr,
                     char *buf)
{
    struct pci_dev *pdev = to_pci_dev(dev);
    return sprintf (buf, "%u\n", pdev->broken_parity_status);
}

static ssize_t broken_parity_status_store(struct device *dev,
                      struct device_attribute *attr,
                      const char *buf, size_t count)
{
    struct pci_dev *pdev = to_pci_dev(dev);
    unsigned long val;

    if (strict_strtoul(buf, 0, &val) < 0)
        return -EINVAL;

    pdev->broken_parity_status = !!val;

    return count;
}

static ssize_t local_cpus_show(struct device *dev,
            struct device_attribute *attr, char *buf)
{       
    const struct cpumask *mask;
    int len;

#ifdef CONFIG_NUMA
    mask = (dev_to_node(dev) == -1) ? cpu_online_mask :
                      cpumask_of_node(dev_to_node(dev));
#else
    mask = cpumask_of_pcibus(to_pci_dev(dev)->bus);
#endif
    len = cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
    buf[len++] = '\n';
    buf[len] = '\0';
    return len;
}


static ssize_t local_cpulist_show(struct device *dev,
            struct device_attribute *attr, char *buf)
{
    const struct cpumask *mask;
    int len;

#ifdef CONFIG_NUMA
    mask = (dev_to_node(dev) == -1) ? cpu_online_mask :
                      cpumask_of_node(dev_to_node(dev));
#else
    mask = cpumask_of_pcibus(to_pci_dev(dev)->bus);
#endif
    len = cpulist_scnprintf(buf, PAGE_SIZE-2, mask);
    buf[len++] = '\n';
    buf[len] = '\0';
    return len;
}

/*
 * PCI Bus Class Devices
 */
static ssize_t pci_bus_show_cpuaffinity(struct device *dev,
                    int type,
                    struct device_attribute *attr,
                    char *buf)
{
    int ret;
    const struct cpumask *cpumask;

    cpumask = cpumask_of_pcibus(to_pci_bus(dev));
    ret = type ?
        cpulist_scnprintf(buf, PAGE_SIZE-2, cpumask) :
        cpumask_scnprintf(buf, PAGE_SIZE-2, cpumask);
    buf[ret++] = '\n';
    buf[ret] = '\0';
    return ret;
}

static inline ssize_t pci_bus_show_cpumaskaffinity(struct device *dev,
                    struct device_attribute *attr,
                    char *buf)
{
    return pci_bus_show_cpuaffinity(dev, 0, attr, buf);
}

static inline ssize_t pci_bus_show_cpulistaffinity(struct device *dev,
                    struct device_attribute *attr,
                    char *buf)
{
    return pci_bus_show_cpuaffinity(dev, 1, attr, buf);
}

/* show resources */
static ssize_t
resource_show(struct device * dev, struct device_attribute *attr, char * buf)
{
    struct pci_dev * pci_dev = to_pci_dev(dev);
    char * str = buf;
    int i;
    int max;
    resource_size_t start, end;

    if (pci_dev->subordinate)
        max = DEVICE_COUNT_RESOURCE;
    else
        max = PCI_BRIDGE_RESOURCES;

    for (i = 0; i < max; i++) {
        struct resource *res =  &pci_dev->resource[i];
        pci_resource_to_user(pci_dev, i, res, &start, &end);
        str += sprintf(str,"0x%016llx 0x%016llx 0x%016llx\n",
                   (unsigned long long)start,
                   (unsigned long long)end,
                   (unsigned long long)res->flags);
    }
    return (str - buf);
}

static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct pci_dev *pci_dev = to_pci_dev(dev);

    return sprintf(buf, "pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02x\n",
               pci_dev->vendor, pci_dev->device,
               pci_dev->subsystem_vendor, pci_dev->subsystem_device,
               (u8)(pci_dev->class >> 16), (u8)(pci_dev->class >> 8),
               (u8)(pci_dev->class));
}

static ssize_t is_enabled_store(struct device *dev,
                struct device_attribute *attr, const char *buf,
                size_t count)
{
    struct pci_dev *pdev = to_pci_dev(dev);
    unsigned long val;
    ssize_t result = strict_strtoul(buf, 0, &val);

    if (result < 0)
        return result;

    /* this can crash the machine when done on the "wrong" device */
    if (!capable(CAP_SYS_ADMIN))
        return -EPERM;

    if (!val) {
        if (pci_is_enabled(pdev))
            pci_disable_device(pdev);
        else
            result = -EIO;
    } else
        result = pci_enable_device(pdev);

    return result < 0 ? result : count;
}

static ssize_t is_enabled_show(struct device *dev,
                   struct device_attribute *attr, char *buf)
{
    struct pci_dev *pdev;

    pdev = to_pci_dev (dev);
    return sprintf (buf, "%u\n", atomic_read(&pdev->enable_cnt));
}

#ifdef CONFIG_NUMA
static ssize_t
numa_node_show(struct device *dev, struct device_attribute *attr, char *buf)
{
    return sprintf (buf, "%d\n", dev->numa_node);
}
#endif

static ssize_t
dma_mask_bits_show(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct pci_dev *pdev = to_pci_dev(dev);

    return sprintf (buf, "%d\n", fls64(pdev->dma_mask));
}

static ssize_t
consistent_dma_mask_bits_show(struct device *dev, struct device_attribute *attr,
                 char *buf)
{
    return sprintf (buf, "%d\n", fls64(dev->coherent_dma_mask));
}

static ssize_t
msi_bus_show(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct pci_dev *pdev = to_pci_dev(dev);

    if (!pdev->subordinate)
        return 0;

    return sprintf (buf, "%u\n",
            !(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI));
}

static ssize_t
msi_bus_store(struct device *dev, struct device_attribute *attr,
          const char *buf, size_t count)
{
    struct pci_dev *pdev = to_pci_dev(dev);
    unsigned long val;

    if (strict_strtoul(buf, 0, &val) < 0)
        return -EINVAL;

    /* bad things may happen if the no_msi flag is changed
     * while some drivers are loaded */
    if (!capable(CAP_SYS_ADMIN))
        return -EPERM;

    /* Maybe pci devices without subordinate busses shouldn't even have this
     * attribute in the first place?  */
    if (!pdev->subordinate)
        return count;

    /* Is the flag going to change, or keep the value it already had? */
    if (!(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI) ^
        !!val) {
        pdev->subordinate->bus_flags ^= PCI_BUS_FLAGS_NO_MSI;

        dev_warn(&pdev->dev, "forced subordinate bus to%s support MSI,"
             " bad things could happen\n", val ? "" : " not");
    }

    return count;
}

#ifdef CONFIG_HOTPLUG
static DEFINE_MUTEX(pci_remove_rescan_mutex);
static ssize_t bus_rescan_store(struct bus_type *bus, const char *buf,
                size_t count)
{
    unsigned long val;
    struct pci_bus *b = NULL;

    if (strict_strtoul(buf, 0, &val) < 0)
        return -EINVAL;

    if (val) {
        mutex_lock(&pci_remove_rescan_mutex);
        while ((b = pci_find_next_bus(b)) != NULL)
            pci_rescan_bus(b);
        mutex_unlock(&pci_remove_rescan_mutex);
    }
    return count;
}

struct bus_attribute pci_bus_attrs[] = {
    __ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, bus_rescan_store),
    __ATTR_NULL
};

static ssize_t
dev_rescan_store(struct device *dev, struct device_attribute *attr,
         const char *buf, size_t count)
{
    unsigned long val;
    struct pci_dev *pdev = to_pci_dev(dev);

    if (strict_strtoul(buf, 0, &val) < 0)
        return -EINVAL;

    if (val) {
        mutex_lock(&pci_remove_rescan_mutex);
        pci_rescan_bus(pdev->bus);
        mutex_unlock(&pci_remove_rescan_mutex);
    }
    return count;
}

static void remove_callback(struct device *dev)
{
    struct pci_dev *pdev = to_pci_dev(dev);

    mutex_lock(&pci_remove_rescan_mutex);
    pci_stop_and_remove_bus_device(pdev);
    mutex_unlock(&pci_remove_rescan_mutex);
}

static ssize_t
remove_store(struct device *dev, struct device_attribute *dummy,
         const char *buf, size_t count)
{
    int ret = 0;
    unsigned long val;

    if (strict_strtoul(buf, 0, &val) < 0)
        return -EINVAL;

    /* An attribute cannot be unregistered by one of its own methods,
     * so we have to use this roundabout approach.
     */
    if (val)
        ret = device_schedule_callback(dev, remove_callback);
    if (ret)
        count = ret;
    return count;
}

static ssize_t
dev_bus_rescan_store(struct device *dev, struct device_attribute *attr,
         const char *buf, size_t count)
{
    unsigned long val;
    struct pci_bus *bus = to_pci_bus(dev);

    if (strict_strtoul(buf, 0, &val) < 0)
        return -EINVAL;

    if (val) {
        mutex_lock(&pci_remove_rescan_mutex);
        if (!pci_is_root_bus(bus) && list_empty(&bus->devices))
            pci_rescan_bus_bridge_resize(bus->self);
        else
            pci_rescan_bus(bus);
        mutex_unlock(&pci_remove_rescan_mutex);
    }
    return count;
}

#endif

#if defined(CONFIG_PM_RUNTIME) && defined(CONFIG_ACPI)
static ssize_t d3cold_allowed_store(struct device *dev,
                    struct device_attribute *attr,
                    const char *buf, size_t count)
{
    struct pci_dev *pdev = to_pci_dev(dev);
    unsigned long val;

    if (strict_strtoul(buf, 0, &val) < 0)
        return -EINVAL;

    pdev->d3cold_allowed = !!val;
    pm_runtime_resume(dev);

    return count;
}

static ssize_t d3cold_allowed_show(struct device *dev,
                   struct device_attribute *attr, char *buf)
{
    struct pci_dev *pdev = to_pci_dev(dev);
    return sprintf (buf, "%u\n", pdev->d3cold_allowed);
}
#endif

struct device_attribute pci_dev_attrs[] = {
    __ATTR_RO(resource),
    __ATTR_RO(vendor),
    __ATTR_RO(device),
    __ATTR_RO(subsystem_vendor),
    __ATTR_RO(subsystem_device),
    __ATTR_RO(class),
    __ATTR_RO(irq),
    __ATTR_RO(local_cpus),
    __ATTR_RO(local_cpulist),
    __ATTR_RO(modalias),
#ifdef CONFIG_NUMA
    __ATTR_RO(numa_node),
#endif
    __ATTR_RO(dma_mask_bits),
    __ATTR_RO(consistent_dma_mask_bits),
    __ATTR(enable, 0600, is_enabled_show, is_enabled_store),
    __ATTR(broken_parity_status,(S_IRUGO|S_IWUSR),
        broken_parity_status_show,broken_parity_status_store),
    __ATTR(msi_bus, 0644, msi_bus_show, msi_bus_store),
#ifdef CONFIG_HOTPLUG
    __ATTR(remove, (S_IWUSR|S_IWGRP), NULL, remove_store),
    __ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, dev_rescan_store),
#endif
#if defined(CONFIG_PM_RUNTIME) && defined(CONFIG_ACPI)
    __ATTR(d3cold_allowed, 0644, d3cold_allowed_show, d3cold_allowed_store),
#endif
    __ATTR_NULL,
};

struct device_attribute pcibus_dev_attrs[] = {
#ifdef CONFIG_HOTPLUG
    __ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, dev_bus_rescan_store),
#endif
    __ATTR(cpuaffinity, S_IRUGO, pci_bus_show_cpumaskaffinity, NULL),
    __ATTR(cpulistaffinity, S_IRUGO, pci_bus_show_cpulistaffinity, NULL),
    __ATTR_NULL,
};

static ssize_t
boot_vga_show(struct device *dev, struct device_attribute *attr, char *buf)
{
    struct pci_dev *pdev = to_pci_dev(dev);
    struct pci_dev *vga_dev = vga_default_device();

    if (vga_dev)
        return sprintf(buf, "%u\n", (pdev == vga_dev));

    return sprintf(buf, "%u\n",
        !!(pdev->resource[PCI_ROM_RESOURCE].flags &
           IORESOURCE_ROM_SHADOW));
}
struct device_attribute vga_attr = __ATTR_RO(boot_vga);

static ssize_t
pci_read_config(struct file *filp, struct kobject *kobj,
        struct bin_attribute *bin_attr,
        char *buf, loff_t off, size_t count)
{
    struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
    unsigned int size = 64;
    loff_t init_off = off;
    u8 *data = (u8*) buf;

    /* Several chips lock up trying to read undefined config space */
    if (security_capable(filp->f_cred, &init_user_ns, CAP_SYS_ADMIN) == 0) {
        size = dev->cfg_size;
    } else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
        size = 128;
    }

    if (off > size)
        return 0;
    if (off + count > size) {
        size -= off;
        count = size;
    } else {
        size = count;
    }

    pci_config_pm_runtime_get(dev);

    if ((off & 1) && size) {
        u8 val;
        pci_user_read_config_byte(dev, off, &val);
        data[off - init_off] = val;
        off++;
        size--;
    }

    if ((off & 3) && size > 2) {
        u16 val;
        pci_user_read_config_word(dev, off, &val);
        data[off - init_off] = val & 0xff;
        data[off - init_off + 1] = (val >> 8) & 0xff;
        off += 2;
        size -= 2;
    }

    while (size > 3) {
        u32 val;
        pci_user_read_config_dword(dev, off, &val);
        data[off - init_off] = val & 0xff;
        data[off - init_off + 1] = (val >> 8) & 0xff;
        data[off - init_off + 2] = (val >> 16) & 0xff;
        data[off - init_off + 3] = (val >> 24) & 0xff;
        off += 4;
        size -= 4;
    }

    if (size >= 2) {
        u16 val;
        pci_user_read_config_word(dev, off, &val);
        data[off - init_off] = val & 0xff;
        data[off - init_off + 1] = (val >> 8) & 0xff;
        off += 2;
        size -= 2;
    }

    if (size > 0) {
        u8 val;
        pci_user_read_config_byte(dev, off, &val);
        data[off - init_off] = val;
        off++;
        --size;
    }

    pci_config_pm_runtime_put(dev);

    return count;
}

static ssize_t
pci_write_config(struct file* filp, struct kobject *kobj,
         struct bin_attribute *bin_attr,
         char *buf, loff_t off, size_t count)
{
    struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
    unsigned int size = count;
    loff_t init_off = off;
    u8 *data = (u8*) buf;

    if (off > dev->cfg_size)
        return 0;
    if (off + count > dev->cfg_size) {
        size = dev->cfg_size - off;
        count = size;
    }
    
    pci_config_pm_runtime_get(dev);

    if ((off & 1) && size) {
        pci_user_write_config_byte(dev, off, data[off - init_off]);
        off++;
        size--;
    }
    
    if ((off & 3) && size > 2) {
        u16 val = data[off - init_off];
        val |= (u16) data[off - init_off + 1] << 8;
                pci_user_write_config_word(dev, off, val);
                off += 2;
                size -= 2;
        }

    while (size > 3) {
        u32 val = data[off - init_off];
        val |= (u32) data[off - init_off + 1] << 8;
        val |= (u32) data[off - init_off + 2] << 16;
        val |= (u32) data[off - init_off + 3] << 24;
        pci_user_write_config_dword(dev, off, val);
        off += 4;
        size -= 4;
    }
    
    if (size >= 2) {
        u16 val = data[off - init_off];
        val |= (u16) data[off - init_off + 1] << 8;
        pci_user_write_config_word(dev, off, val);
        off += 2;
        size -= 2;
    }

    if (size) {
        pci_user_write_config_byte(dev, off, data[off - init_off]);
        off++;
        --size;
    }

    pci_config_pm_runtime_put(dev);

    return count;
}

static ssize_t
read_vpd_attr(struct file *filp, struct kobject *kobj,
          struct bin_attribute *bin_attr,
          char *buf, loff_t off, size_t count)
{
    struct pci_dev *dev =
        to_pci_dev(container_of(kobj, struct device, kobj));

    if (off > bin_attr->size)
        count = 0;
    else if (count > bin_attr->size - off)
        count = bin_attr->size - off;

    return pci_read_vpd(dev, off, count, buf);
}

static ssize_t
write_vpd_attr(struct file *filp, struct kobject *kobj,
           struct bin_attribute *bin_attr,
           char *buf, loff_t off, size_t count)
{
    struct pci_dev *dev =
        to_pci_dev(container_of(kobj, struct device, kobj));

    if (off > bin_attr->size)
        count = 0;
    else if (count > bin_attr->size - off)
        count = bin_attr->size - off;

    return pci_write_vpd(dev, off, count, buf);
}

#ifdef HAVE_PCI_LEGACY

static ssize_t
pci_read_legacy_io(struct file *filp, struct kobject *kobj,
           struct bin_attribute *bin_attr,
           char *buf, loff_t off, size_t count)
{
        struct pci_bus *bus = to_pci_bus(container_of(kobj,
                                                      struct device,
                              kobj));

        /* Only support 1, 2 or 4 byte accesses */
        if (count != 1 && count != 2 && count != 4)
                return -EINVAL;

        return pci_legacy_read(bus, off, (u32 *)buf, count);
}

static ssize_t
pci_write_legacy_io(struct file *filp, struct kobject *kobj,
            struct bin_attribute *bin_attr,
            char *buf, loff_t off, size_t count)
{
        struct pci_bus *bus = to_pci_bus(container_of(kobj,
                              struct device,
                              kobj));
        /* Only support 1, 2 or 4 byte accesses */
        if (count != 1 && count != 2 && count != 4)
                return -EINVAL;

        return pci_legacy_write(bus, off, *(u32 *)buf, count);
}

static int
pci_mmap_legacy_mem(struct file *filp, struct kobject *kobj,
            struct bin_attribute *attr,
                    struct vm_area_struct *vma)
{
        struct pci_bus *bus = to_pci_bus(container_of(kobj,
                                                      struct device,
                              kobj));

        return pci_mmap_legacy_page_range(bus, vma, pci_mmap_mem);
}

static int
pci_mmap_legacy_io(struct file *filp, struct kobject *kobj,
           struct bin_attribute *attr,
           struct vm_area_struct *vma)
{
        struct pci_bus *bus = to_pci_bus(container_of(kobj,
                                                      struct device,
                              kobj));

        return pci_mmap_legacy_page_range(bus, vma, pci_mmap_io);
}

void __weak
pci_adjust_legacy_attr(struct pci_bus *b, enum pci_mmap_state mmap_type)
{
    return;
}

void pci_create_legacy_files(struct pci_bus *b)
{
    int error;

    b->legacy_io = kzalloc(sizeof(struct bin_attribute) * 2,
                   GFP_ATOMIC);
    if (!b->legacy_io)
        goto kzalloc_err;

    sysfs_bin_attr_init(b->legacy_io);
    b->legacy_io->attr.name = "legacy_io";
    b->legacy_io->size = 0xffff;
    b->legacy_io->attr.mode = S_IRUSR | S_IWUSR;
    b->legacy_io->read = pci_read_legacy_io;
    b->legacy_io->write = pci_write_legacy_io;
    b->legacy_io->mmap = pci_mmap_legacy_io;
    pci_adjust_legacy_attr(b, pci_mmap_io);
    error = device_create_bin_file(&b->dev, b->legacy_io);
    if (error)
        goto legacy_io_err;

    /* Allocated above after the legacy_io struct */
    b->legacy_mem = b->legacy_io + 1;
    sysfs_bin_attr_init(b->legacy_mem);
    b->legacy_mem->attr.name = "legacy_mem";
    b->legacy_mem->size = 1024*1024;
    b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;
    b->legacy_mem->mmap = pci_mmap_legacy_mem;
    pci_adjust_legacy_attr(b, pci_mmap_mem);
    error = device_create_bin_file(&b->dev, b->legacy_mem);
    if (error)
        goto legacy_mem_err;

    return;

legacy_mem_err:
    device_remove_bin_file(&b->dev, b->legacy_io);
legacy_io_err:
    kfree(b->legacy_io);
    b->legacy_io = NULL;
kzalloc_err:
    printk(KERN_WARNING "pci: warning: could not create legacy I/O port "
           "and ISA memory resources to sysfs\n");
    return;
}

void pci_remove_legacy_files(struct pci_bus *b)
{
    if (b->legacy_io) {
        device_remove_bin_file(&b->dev, b->legacy_io);
        device_remove_bin_file(&b->dev, b->legacy_mem);
        kfree(b->legacy_io); /* both are allocated here */
    }
}
#endif /* HAVE_PCI_LEGACY */

#ifdef HAVE_PCI_MMAP

int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
          enum pci_mmap_api mmap_api)
{
    unsigned long nr, start, size, pci_start;

    if (pci_resource_len(pdev, resno) == 0)
        return 0;
    nr = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
    start = vma->vm_pgoff;
    size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1;
    pci_start = (mmap_api == PCI_MMAP_PROCFS) ?
            pci_resource_start(pdev, resno) >> PAGE_SHIFT : 0;
    if (start >= pci_start && start < pci_start + size &&
            start + nr <= pci_start + size)
        return 1;
    return 0;
}

static int
pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
          struct vm_area_struct *vma, int write_combine)
{
    struct pci_dev *pdev = to_pci_dev(container_of(kobj,
                               struct device, kobj));
    struct resource *res = attr->private;
    enum pci_mmap_state mmap_type;
    resource_size_t start, end;
    int i;

    for (i = 0; i < PCI_ROM_RESOURCE; i++)
        if (res == &pdev->resource[i])
            break;
    if (i >= PCI_ROM_RESOURCE)
        return -ENODEV;

    if (!pci_mmap_fits(pdev, i, vma, PCI_MMAP_SYSFS)) {
        WARN(1, "process \"%s\" tried to map 0x%08lx bytes "
            "at page 0x%08lx on %s BAR %d (start 0x%16Lx, size 0x%16Lx)\n",
            current->comm, vma->vm_end-vma->vm_start, vma->vm_pgoff,
            pci_name(pdev), i,
            (u64)pci_resource_start(pdev, i),
            (u64)pci_resource_len(pdev, i));
        return -EINVAL;
    }

    /* pci_mmap_page_range() expects the same kind of entry as coming
     * from /proc/bus/pci/ which is a "user visible" value. If this is
     * different from the resource itself, arch will do necessary fixup.
     */
    pci_resource_to_user(pdev, i, res, &start, &end);
    vma->vm_pgoff += start >> PAGE_SHIFT;
    mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;

    if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(start))
        return -EINVAL;

    return pci_mmap_page_range(pdev, vma, mmap_type, write_combine);
}

static int
pci_mmap_resource_uc(struct file *filp, struct kobject *kobj,
             struct bin_attribute *attr,
             struct vm_area_struct *vma)
{
    return pci_mmap_resource(kobj, attr, vma, 0);
}

static int
pci_mmap_resource_wc(struct file *filp, struct kobject *kobj,
             struct bin_attribute *attr,
             struct vm_area_struct *vma)
{
    return pci_mmap_resource(kobj, attr, vma, 1);
}

static ssize_t
pci_resource_io(struct file *filp, struct kobject *kobj,
        struct bin_attribute *attr, char *buf,
        loff_t off, size_t count, bool write)
{
    struct pci_dev *pdev = to_pci_dev(container_of(kobj,
                               struct device, kobj));
    struct resource *res = attr->private;
    unsigned long port = off;
    int i;

    for (i = 0; i < PCI_ROM_RESOURCE; i++)
        if (res == &pdev->resource[i])
            break;
    if (i >= PCI_ROM_RESOURCE)
        return -ENODEV;

    port += pci_resource_start(pdev, i);

    if (port > pci_resource_end(pdev, i))
        return 0;

    if (port + count - 1 > pci_resource_end(pdev, i))
        return -EINVAL;

    switch (count) {
    case 1:
        if (write)
            outb(*(u8 *)buf, port);
        else
            *(u8 *)buf = inb(port);
        return 1;
    case 2:
        if (write)
            outw(*(u16 *)buf, port);
        else
            *(u16 *)buf = inw(port);
        return 2;
    case 4:
        if (write)
            outl(*(u32 *)buf, port);
        else
            *(u32 *)buf = inl(port);
        return 4;
    }
    return -EINVAL;
}

static ssize_t
pci_read_resource_io(struct file *filp, struct kobject *kobj,
             struct bin_attribute *attr, char *buf,
             loff_t off, size_t count)
{
    return pci_resource_io(filp, kobj, attr, buf, off, count, false);
}

static ssize_t
pci_write_resource_io(struct file *filp, struct kobject *kobj,
              struct bin_attribute *attr, char *buf,
              loff_t off, size_t count)
{
    return pci_resource_io(filp, kobj, attr, buf, off, count, true);
}

static void
pci_remove_resource_files(struct pci_dev *pdev)
{
    int i;

    for (i = 0; i < PCI_ROM_RESOURCE; i++) {
        struct bin_attribute *res_attr;

        res_attr = pdev->res_attr[i];
        if (res_attr) {
            sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
            kfree(res_attr);
        }

        res_attr = pdev->res_attr_wc[i];
        if (res_attr) {
            sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
            kfree(res_attr);
        }
    }
}

static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine)
{
    /* allocate attribute structure, piggyback attribute name */
    int name_len = write_combine ? 13 : 10;
    struct bin_attribute *res_attr;
    int retval;

    res_attr = kzalloc(sizeof(*res_attr) + name_len, GFP_ATOMIC);
    if (res_attr) {
        char *res_attr_name = (char *)(res_attr + 1);

        sysfs_bin_attr_init(res_attr);
        if (write_combine) {
            pdev->res_attr_wc[num] = res_attr;
            sprintf(res_attr_name, "resource%d_wc", num);
            res_attr->mmap = pci_mmap_resource_wc;
        } else {
            pdev->res_attr[num] = res_attr;
            sprintf(res_attr_name, "resource%d", num);
            res_attr->mmap = pci_mmap_resource_uc;
        }
        if (pci_resource_flags(pdev, num) & IORESOURCE_IO) {
            res_attr->read = pci_read_resource_io;
            res_attr->write = pci_write_resource_io;
        }
        res_attr->attr.name = res_attr_name;
        res_attr->attr.mode = S_IRUSR | S_IWUSR;
        res_attr->size = pci_resource_len(pdev, num);
        res_attr->private = &pdev->resource[num];
        retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
    } else
        retval = -ENOMEM;

    return retval;
}

static int pci_create_resource_files(struct pci_dev *pdev)
{
    int i;
    int retval;

    /* Expose the PCI resources from this device as files */
    for (i = 0; i < PCI_ROM_RESOURCE; i++) {

        /* skip empty resources */
        if (!pci_resource_len(pdev, i))
            continue;

        retval = pci_create_attr(pdev, i, 0);
        /* for prefetchable resources, create a WC mappable file */
        if (!retval && pdev->resource[i].flags & IORESOURCE_PREFETCH)
            retval = pci_create_attr(pdev, i, 1);

        if (retval) {
            pci_remove_resource_files(pdev);
            return retval;
        }
    }
    return 0;
}
#else /* !HAVE_PCI_MMAP */
int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }
void __weak pci_remove_resource_files(struct pci_dev *dev) { return; }
#endif /* HAVE_PCI_MMAP */

static ssize_t
pci_write_rom(struct file *filp, struct kobject *kobj,
          struct bin_attribute *bin_attr,
          char *buf, loff_t off, size_t count)
{
    struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));

    if ((off ==  0) && (*buf == '0') && (count == 2))
        pdev->rom_attr_enabled = 0;
    else
        pdev->rom_attr_enabled = 1;

    return count;
}

static ssize_t
pci_read_rom(struct file *filp, struct kobject *kobj,
         struct bin_attribute *bin_attr,
         char *buf, loff_t off, size_t count)
{
    struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
    void __iomem *rom;
    size_t size;

    if (!pdev->rom_attr_enabled)
        return -EINVAL;
    
    rom = pci_map_rom(pdev, &size); /* size starts out as PCI window size */
    if (!rom || !size)
        return -EIO;
        
    if (off >= size)
        count = 0;
    else {
        if (off + count > size)
            count = size - off;
        
        memcpy_fromio(buf, rom + off, count);
    }
    pci_unmap_rom(pdev, rom);
        
    return count;
}

static struct bin_attribute pci_config_attr = {
    .attr = {
        .name = "config",
        .mode = S_IRUGO | S_IWUSR,
    },
    .size = PCI_CFG_SPACE_SIZE,
    .read = pci_read_config,
    .write = pci_write_config,
};

static struct bin_attribute pcie_config_attr = {
    .attr = {
        .name = "config",
        .mode = S_IRUGO | S_IWUSR,
    },
    .size = PCI_CFG_SPACE_EXP_SIZE,
    .read = pci_read_config,
    .write = pci_write_config,
};

int __weak pcibios_add_platform_entries(struct pci_dev *dev)
{
    return 0;
}

static ssize_t reset_store(struct device *dev,
               struct device_attribute *attr, const char *buf,
               size_t count)
{
    struct pci_dev *pdev = to_pci_dev(dev);
    unsigned long val;
    ssize_t result = strict_strtoul(buf, 0, &val);

    if (result < 0)
        return result;

    if (val != 1)
        return -EINVAL;

    result = pci_reset_function(pdev);
    if (result < 0)
        return result;

    return count;
}

static struct device_attribute reset_attr = __ATTR(reset, 0200, NULL, reset_store);

static int pci_create_capabilities_sysfs(struct pci_dev *dev)
{
    int retval;
    struct bin_attribute *attr;

    /* If the device has VPD, try to expose it in sysfs. */
    if (dev->vpd) {
        attr = kzalloc(sizeof(*attr), GFP_ATOMIC);
        if (!attr)
            return -ENOMEM;

        sysfs_bin_attr_init(attr);
        attr->size = dev->vpd->len;
        attr->attr.name = "vpd";
        attr->attr.mode = S_IRUSR | S_IWUSR;
        attr->read = read_vpd_attr;
        attr->write = write_vpd_attr;
        retval = sysfs_create_bin_file(&dev->dev.kobj, attr);
        if (retval) {
            kfree(attr);
            return retval;
        }
        dev->vpd->attr = attr;
    }

    /* Active State Power Management */
    pcie_aspm_create_sysfs_dev_files(dev);

    if (!pci_probe_reset_function(dev)) {
        retval = device_create_file(&dev->dev, &reset_attr);
        if (retval)
            goto error;
        dev->reset_fn = 1;
    }
    return 0;

error:
    pcie_aspm_remove_sysfs_dev_files(dev);
    if (dev->vpd && dev->vpd->attr) {
        sysfs_remove_bin_file(&dev->dev.kobj, dev->vpd->attr);
        kfree(dev->vpd->attr);
    }

    return retval;
}

int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
{
    int retval;
    int rom_size = 0;
    struct bin_attribute *attr;

    if (!sysfs_initialized)
        return -EACCES;

    if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
        retval = sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
    else
        retval = sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
    if (retval)
        goto err;

    retval = pci_create_resource_files(pdev);
    if (retval)
        goto err_config_file;

    if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
        rom_size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
    else if (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW)
        rom_size = 0x20000;

    /* If the device has a ROM, try to expose it in sysfs. */
    if (rom_size) {
        attr = kzalloc(sizeof(*attr), GFP_ATOMIC);
        if (!attr) {
            retval = -ENOMEM;
            goto err_resource_files;
        }
        sysfs_bin_attr_init(attr);
        attr->size = rom_size;
        attr->attr.name = "rom";
        attr->attr.mode = S_IRUSR | S_IWUSR;
        attr->read = pci_read_rom;
        attr->write = pci_write_rom;
        retval = sysfs_create_bin_file(&pdev->dev.kobj, attr);
        if (retval) {
            kfree(attr);
            goto err_resource_files;
        }
        pdev->rom_attr = attr;
    }

    if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA) {
        retval = device_create_file(&pdev->dev, &vga_attr);
        if (retval)
            goto err_rom_file;
    }

    /* add platform-specific attributes */
    retval = pcibios_add_platform_entries(pdev);
    if (retval)
        goto err_vga_file;

    /* add sysfs entries for various capabilities */
    retval = pci_create_capabilities_sysfs(pdev);
    if (retval)
        goto err_vga_file;

    pci_create_firmware_label_files(pdev);

    return 0;

err_vga_file:
    if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
        device_remove_file(&pdev->dev, &vga_attr);
err_rom_file:
    if (rom_size) {
        sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
        kfree(pdev->rom_attr);
        pdev->rom_attr = NULL;
    }
err_resource_files:
    pci_remove_resource_files(pdev);
err_config_file:
    if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
        sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
    else
        sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
err:
    return retval;
}

static void pci_remove_capabilities_sysfs(struct pci_dev *dev)
{
    if (dev->vpd && dev->vpd->attr) {
        sysfs_remove_bin_file(&dev->dev.kobj, dev->vpd->attr);
        kfree(dev->vpd->attr);
    }

    pcie_aspm_remove_sysfs_dev_files(dev);
    if (dev->reset_fn) {
        device_remove_file(&dev->dev, &reset_attr);
        dev->reset_fn = 0;
    }
}

void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
{
    int rom_size = 0;

    if (!sysfs_initialized)
        return;

    pci_remove_capabilities_sysfs(pdev);

    if (pdev->cfg_size < PCI_CFG_SPACE_EXP_SIZE)
        sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
    else
        sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);

    pci_remove_resource_files(pdev);

    if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
        rom_size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
    else if (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW)
        rom_size = 0x20000;

    if (rom_size && pdev->rom_attr) {
        sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
        kfree(pdev->rom_attr);
    }

    pci_remove_firmware_label_files(pdev);

}

static int __init pci_sysfs_init(void)
{
    struct pci_dev *pdev = NULL;
    int retval;

    sysfs_initialized = 1;
    for_each_pci_dev(pdev) {
        retval = pci_create_sysfs_dev_files(pdev);
        if (retval) {
            pci_dev_put(pdev);
            return retval;
        }
    }

    return 0;
}

late_initcall(pci_sysfs_init);