root/drivers/pci/pci-sysfs.c
// SPDX-License-Identifier: GPL-2.0
/*
 * (C) Copyright 2002-2004 Greg Kroah-Hartman <greg@kroah.com>
 * (C) Copyright 2002-2004 IBM Corp.
 * (C) Copyright 2003 Matthew Wilcox
 * (C) Copyright 2003 Hewlett-Packard
 * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
 * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
 *
 * File attributes for PCI devices
 *
 * Modeled after usb's driverfs.c
 */

#include <linux/bitfield.h>
#include <linux/cleanup.h>
#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/slab.h>
#include <linux/vgaarb.h>
#include <linux/pm_runtime.h>
#include <linux/msi.h>
#include <linux/of.h>
#include <linux/aperture.h>
#include <linux/unaligned.h>
#include "pci.h"

#ifndef ARCH_PCI_DEV_GROUPS
#define ARCH_PCI_DEV_GROUPS
#endif

/* 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 sysfs_emit(buf, format_string, pdev->field);             \
}                                                                       \
static DEVICE_ATTR_RO(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(revision, "0x%02x\n");
pci_config_attr(class, "0x%06x\n");

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

#ifdef CONFIG_PCI_MSI
        /*
         * For MSI, show the first MSI IRQ; for all other cases including
         * MSI-X, show the legacy INTx IRQ.
         */
        if (pdev->msi_enabled)
                return sysfs_emit(buf, "%u\n", pci_irq_vector(pdev, 0));
#endif

        return sysfs_emit(buf, "%u\n", pdev->irq);
}
static DEVICE_ATTR_RO(irq);

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 sysfs_emit(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 (kstrtoul(buf, 0, &val) < 0)
                return -EINVAL;

        pdev->broken_parity_status = !!val;

        return count;
}
static DEVICE_ATTR_RW(broken_parity_status);

static ssize_t pci_dev_show_local_cpu(struct device *dev, bool list,
                                      struct device_attribute *attr, char *buf)
{
        const struct cpumask *mask;

#ifdef CONFIG_NUMA
        if (dev_to_node(dev) == NUMA_NO_NODE)
                mask = cpu_online_mask;
        else
                mask = cpumask_of_node(dev_to_node(dev));
#else
        mask = cpumask_of_pcibus(to_pci_dev(dev)->bus);
#endif
        return cpumap_print_to_pagebuf(list, buf, mask);
}

static ssize_t local_cpus_show(struct device *dev,
                               struct device_attribute *attr, char *buf)
{
        return pci_dev_show_local_cpu(dev, false, attr, buf);
}
static DEVICE_ATTR_RO(local_cpus);

static ssize_t local_cpulist_show(struct device *dev,
                                  struct device_attribute *attr, char *buf)
{
        return pci_dev_show_local_cpu(dev, true, attr, buf);
}
static DEVICE_ATTR_RO(local_cpulist);

/*
 * PCI Bus Class Devices
 */
static ssize_t cpuaffinity_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        const struct cpumask *cpumask = cpumask_of_pcibus(to_pci_bus(dev));

        return cpumap_print_to_pagebuf(false, buf, cpumask);
}
static DEVICE_ATTR_RO(cpuaffinity);

static ssize_t cpulistaffinity_show(struct device *dev,
                                    struct device_attribute *attr, char *buf)
{
        const struct cpumask *cpumask = cpumask_of_pcibus(to_pci_bus(dev));

        return cpumap_print_to_pagebuf(true, buf, cpumask);
}
static DEVICE_ATTR_RO(cpulistaffinity);

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

        return sysfs_emit(buf, "%s\n", pci_power_name(pdev->current_state));
}
static DEVICE_ATTR_RO(power_state);

/* 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);
        int i;
        int max;
        resource_size_t start, end;
        size_t len = 0;

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

        for (i = 0; i < max; i++) {
                struct resource *res = pci_resource_n(pci_dev, i);
                struct resource zerores = {};

                /* For backwards compatibility */
                if (pci_resource_is_bridge_win(i) &&
                    res->flags & (IORESOURCE_UNSET | IORESOURCE_DISABLED))
                        res = &zerores;

                pci_resource_to_user(pci_dev, i, res, &start, &end);
                len += sysfs_emit_at(buf, len, "0x%016llx 0x%016llx 0x%016llx\n",
                                     (unsigned long long)start,
                                     (unsigned long long)end,
                                     (unsigned long long)res->flags);
        }
        return len;
}
static DEVICE_ATTR_RO(resource);

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

        return sysfs_emit(buf, "%s\n",
                          pci_speed_string(pcie_get_speed_cap(pdev)));
}
static DEVICE_ATTR_RO(max_link_speed);

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

        /* We read PCI_EXP_LNKCAP, so we need the device to be accessible. */
        pci_config_pm_runtime_get(pdev);
        ret = sysfs_emit(buf, "%u\n", pcie_get_width_cap(pdev));
        pci_config_pm_runtime_put(pdev);

        return ret;
}
static DEVICE_ATTR_RO(max_link_width);

static ssize_t current_link_speed_show(struct device *dev,
                                       struct device_attribute *attr, char *buf)
{
        struct pci_dev *pci_dev = to_pci_dev(dev);
        u16 linkstat;
        int err;
        enum pci_bus_speed speed;

        pci_config_pm_runtime_get(pci_dev);
        err = pcie_capability_read_word(pci_dev, PCI_EXP_LNKSTA, &linkstat);
        pci_config_pm_runtime_put(pci_dev);

        if (err)
                return -EINVAL;

        speed = pcie_link_speed[linkstat & PCI_EXP_LNKSTA_CLS];

        return sysfs_emit(buf, "%s\n", pci_speed_string(speed));
}
static DEVICE_ATTR_RO(current_link_speed);

static ssize_t current_link_width_show(struct device *dev,
                                       struct device_attribute *attr, char *buf)
{
        struct pci_dev *pci_dev = to_pci_dev(dev);
        u16 linkstat;
        int err;

        pci_config_pm_runtime_get(pci_dev);
        err = pcie_capability_read_word(pci_dev, PCI_EXP_LNKSTA, &linkstat);
        pci_config_pm_runtime_put(pci_dev);

        if (err)
                return -EINVAL;

        return sysfs_emit(buf, "%u\n", FIELD_GET(PCI_EXP_LNKSTA_NLW, linkstat));
}
static DEVICE_ATTR_RO(current_link_width);

static ssize_t secondary_bus_number_show(struct device *dev,
                                         struct device_attribute *attr,
                                         char *buf)
{
        struct pci_dev *pci_dev = to_pci_dev(dev);
        u8 sec_bus;
        int err;

        pci_config_pm_runtime_get(pci_dev);
        err = pci_read_config_byte(pci_dev, PCI_SECONDARY_BUS, &sec_bus);
        pci_config_pm_runtime_put(pci_dev);

        if (err)
                return -EINVAL;

        return sysfs_emit(buf, "%u\n", sec_bus);
}
static DEVICE_ATTR_RO(secondary_bus_number);

static ssize_t subordinate_bus_number_show(struct device *dev,
                                           struct device_attribute *attr,
                                           char *buf)
{
        struct pci_dev *pci_dev = to_pci_dev(dev);
        u8 sub_bus;
        int err;

        pci_config_pm_runtime_get(pci_dev);
        err = pci_read_config_byte(pci_dev, PCI_SUBORDINATE_BUS, &sub_bus);
        pci_config_pm_runtime_put(pci_dev);

        if (err)
                return -EINVAL;

        return sysfs_emit(buf, "%u\n", sub_bus);
}
static DEVICE_ATTR_RO(subordinate_bus_number);

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

        return sysfs_emit(buf, "%u\n", pci_ari_enabled(pci_dev->bus));
}
static DEVICE_ATTR_RO(ari_enabled);

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

        return sysfs_emit(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 DEVICE_ATTR_RO(modalias);

static ssize_t enable_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 = 0;

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

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

        device_lock(dev);
        if (dev->driver)
                result = -EBUSY;
        else if (val)
                result = pci_enable_device(pdev);
        else if (pci_is_enabled(pdev))
                pci_disable_device(pdev);
        else
                result = -EIO;
        device_unlock(dev);

        return result < 0 ? result : count;
}

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

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

#ifdef CONFIG_NUMA
static ssize_t numa_node_store(struct device *dev,
                               struct device_attribute *attr, const char *buf,
                               size_t count)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        int node;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        if (kstrtoint(buf, 0, &node) < 0)
                return -EINVAL;

        if ((node < 0 && node != NUMA_NO_NODE) || node >= MAX_NUMNODES)
                return -EINVAL;

        if (node != NUMA_NO_NODE && !node_online(node))
                return -EINVAL;

        if (node == dev->numa_node)
                return count;

        add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
        pci_alert(pdev, FW_BUG "Overriding NUMA node to %d.  Contact your vendor for updates.",
                  node);

        dev->numa_node = node;
        return count;
}

static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr,
                              char *buf)
{
        return sysfs_emit(buf, "%d\n", dev->numa_node);
}
static DEVICE_ATTR_RW(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 sysfs_emit(buf, "%d\n", fls64(pdev->dma_mask));
}
static DEVICE_ATTR_RO(dma_mask_bits);

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

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

        return sysfs_emit(buf, "%u\n", subordinate ?
                          !(subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI)
                            : !pdev->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);
        struct pci_bus *subordinate = pdev->subordinate;
        unsigned long val;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

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

        /*
         * "no_msi" and "bus_flags" only affect what happens when a driver
         * requests MSI or MSI-X.  They don't affect any drivers that have
         * already requested MSI or MSI-X.
         */
        if (!subordinate) {
                pdev->no_msi = !val;
                pci_info(pdev, "MSI/MSI-X %s for future drivers\n",
                         val ? "allowed" : "disallowed");
                return count;
        }

        if (val)
                subordinate->bus_flags &= ~PCI_BUS_FLAGS_NO_MSI;
        else
                subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;

        dev_info(&subordinate->dev, "MSI/MSI-X %s for future drivers of devices on this bus\n",
                 val ? "allowed" : "disallowed");
        return count;
}
static DEVICE_ATTR_RW(msi_bus);

static ssize_t rescan_store(const struct bus_type *bus, const char *buf, size_t count)
{
        unsigned long val;
        struct pci_bus *b = NULL;

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

        if (val) {
                pci_lock_rescan_remove();
                while ((b = pci_find_next_bus(b)) != NULL)
                        pci_rescan_bus(b);
                pci_unlock_rescan_remove();
        }
        return count;
}
static BUS_ATTR_WO(rescan);

static struct attribute *pci_bus_attrs[] = {
        &bus_attr_rescan.attr,
        NULL,
};

static const struct attribute_group pci_bus_group = {
        .attrs = pci_bus_attrs,
};

const struct attribute_group *pci_bus_groups[] = {
        &pci_bus_group,
        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 (kstrtoul(buf, 0, &val) < 0)
                return -EINVAL;

        if (val) {
                pci_lock_rescan_remove();
                pci_rescan_bus(pdev->bus);
                pci_unlock_rescan_remove();
        }
        return count;
}
static struct device_attribute dev_attr_dev_rescan = __ATTR(rescan, 0200, NULL,
                                                            dev_rescan_store);

static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
                            const char *buf, size_t count)
{
        unsigned long val;

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

        if (val && device_remove_file_self(dev, attr))
                pci_stop_and_remove_bus_device_locked(to_pci_dev(dev));
        return count;
}
static DEVICE_ATTR_IGNORE_LOCKDEP(remove, 0220, NULL,
                                  remove_store);

static ssize_t 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 (kstrtoul(buf, 0, &val) < 0)
                return -EINVAL;

        if (val) {
                pci_lock_rescan_remove();
                if (!pci_is_root_bus(bus) && list_empty(&bus->devices))
                        pci_rescan_bus_bridge_resize(bus->self);
                else
                        pci_rescan_bus(bus);
                pci_unlock_rescan_remove();
        }
        return count;
}
static struct device_attribute dev_attr_bus_rescan = __ATTR(rescan, 0200, NULL,
                                                            bus_rescan_store);

static ssize_t reset_subordinate_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 (!capable(CAP_SYS_ADMIN))
                return -EPERM;

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

        if (val) {
                int ret = pci_try_reset_bridge(pdev);

                if (ret)
                        return ret;
        }

        return count;
}
static DEVICE_ATTR_WO(reset_subordinate);

#if defined(CONFIG_PM) && 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 (kstrtoul(buf, 0, &val) < 0)
                return -EINVAL;

        pdev->d3cold_allowed = !!val;
        pci_bridge_d3_update(pdev);

        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 sysfs_emit(buf, "%u\n", pdev->d3cold_allowed);
}
static DEVICE_ATTR_RW(d3cold_allowed);
#endif

#ifdef CONFIG_OF
static ssize_t devspec_show(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        struct device_node *np = pci_device_to_OF_node(pdev);

        if (np == NULL)
                return 0;
        return sysfs_emit(buf, "%pOF\n", np);
}
static DEVICE_ATTR_RO(devspec);
#endif

static struct attribute *pci_dev_attrs[] = {
        &dev_attr_power_state.attr,
        &dev_attr_resource.attr,
        &dev_attr_vendor.attr,
        &dev_attr_device.attr,
        &dev_attr_subsystem_vendor.attr,
        &dev_attr_subsystem_device.attr,
        &dev_attr_revision.attr,
        &dev_attr_class.attr,
        &dev_attr_irq.attr,
        &dev_attr_local_cpus.attr,
        &dev_attr_local_cpulist.attr,
        &dev_attr_modalias.attr,
#ifdef CONFIG_NUMA
        &dev_attr_numa_node.attr,
#endif
        &dev_attr_dma_mask_bits.attr,
        &dev_attr_consistent_dma_mask_bits.attr,
        &dev_attr_enable.attr,
        &dev_attr_broken_parity_status.attr,
        &dev_attr_msi_bus.attr,
#if defined(CONFIG_PM) && defined(CONFIG_ACPI)
        &dev_attr_d3cold_allowed.attr,
#endif
#ifdef CONFIG_OF
        &dev_attr_devspec.attr,
#endif
        &dev_attr_ari_enabled.attr,
        NULL,
};

static struct attribute *pci_bridge_attrs[] = {
        &dev_attr_subordinate_bus_number.attr,
        &dev_attr_secondary_bus_number.attr,
        &dev_attr_reset_subordinate.attr,
        NULL,
};

static struct attribute *pcie_dev_attrs[] = {
        &dev_attr_current_link_speed.attr,
        &dev_attr_current_link_width.attr,
        &dev_attr_max_link_width.attr,
        &dev_attr_max_link_speed.attr,
        NULL,
};

static struct attribute *pcibus_attrs[] = {
        &dev_attr_bus_rescan.attr,
        &dev_attr_cpuaffinity.attr,
        &dev_attr_cpulistaffinity.attr,
        NULL,
};

static const struct attribute_group pcibus_group = {
        .attrs = pcibus_attrs,
};

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 sysfs_emit(buf, "%u\n", (pdev == vga_dev));

        return sysfs_emit(buf, "%u\n",
                          !!(pci_resource_flags(pdev, PCI_ROM_RESOURCE) &
                             IORESOURCE_ROM_SHADOW));
}
static DEVICE_ATTR_RO(boot_vga);

static ssize_t serial_number_show(struct device *dev,
                                  struct device_attribute *attr, char *buf)
{
        struct pci_dev *pci_dev = to_pci_dev(dev);
        u64 dsn;
        u8 bytes[8];

        dsn = pci_get_dsn(pci_dev);
        if (!dsn)
                return -EIO;

        put_unaligned_be64(dsn, bytes);
        return sysfs_emit(buf, "%8phD\n", bytes);
}
static DEVICE_ATTR_ADMIN_RO(serial_number);

static ssize_t pci_read_config(struct file *filp, struct kobject *kobj,
                               const struct bin_attribute *bin_attr, char *buf,
                               loff_t off, size_t count)
{
        struct pci_dev *dev = to_pci_dev(kobj_to_dev(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 (file_ns_capable(filp, &init_user_ns, CAP_SYS_ADMIN))
                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;
                cond_resched();
        }

        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;
        }

        pci_config_pm_runtime_put(dev);

        return count;
}

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

        ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
        if (ret)
                return ret;

        if (resource_is_exclusive(&dev->driver_exclusive_resource, off,
                                  count)) {
                pci_warn_once(dev, "%s: Unexpected write to kernel-exclusive config offset %llx",
                              current->comm, off);
                add_taint(TAINT_USER, LOCKDEP_STILL_OK);
        }

        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]);

        pci_config_pm_runtime_put(dev);

        return count;
}
static const BIN_ATTR(config, 0644, pci_read_config, pci_write_config, 0);

static const struct bin_attribute *const pci_dev_config_attrs[] = {
        &bin_attr_config,
        NULL,
};

static size_t pci_dev_config_attr_bin_size(struct kobject *kobj,
                                           const struct bin_attribute *a,
                                           int n)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));

        if (pdev->cfg_size > PCI_CFG_SPACE_SIZE)
                return PCI_CFG_SPACE_EXP_SIZE;
        return PCI_CFG_SPACE_SIZE;
}

static const struct attribute_group pci_dev_config_attr_group = {
        .bin_attrs = pci_dev_config_attrs,
        .bin_size = pci_dev_config_attr_bin_size,
};

#ifdef HAVE_PCI_LEGACY
/**
 * pci_read_legacy_io - read byte(s) from legacy I/O port space
 * @filp: open sysfs file
 * @kobj: kobject corresponding to file to read from
 * @bin_attr: struct bin_attribute for this file
 * @buf: buffer to store results
 * @off: offset into legacy I/O port space
 * @count: number of bytes to read
 *
 * Reads 1, 2, or 4 bytes from legacy I/O port space using an arch specific
 * callback routine (pci_legacy_read).
 */
static ssize_t pci_read_legacy_io(struct file *filp, struct kobject *kobj,
                                  const struct bin_attribute *bin_attr,
                                  char *buf, loff_t off, size_t count)
{
        struct pci_bus *bus = to_pci_bus(kobj_to_dev(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);
}

/**
 * pci_write_legacy_io - write byte(s) to legacy I/O port space
 * @filp: open sysfs file
 * @kobj: kobject corresponding to file to read from
 * @bin_attr: struct bin_attribute for this file
 * @buf: buffer containing value to be written
 * @off: offset into legacy I/O port space
 * @count: number of bytes to write
 *
 * Writes 1, 2, or 4 bytes from legacy I/O port space using an arch specific
 * callback routine (pci_legacy_write).
 */
static ssize_t pci_write_legacy_io(struct file *filp, struct kobject *kobj,
                                   const struct bin_attribute *bin_attr,
                                   char *buf, loff_t off, size_t count)
{
        struct pci_bus *bus = to_pci_bus(kobj_to_dev(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);
}

/**
 * pci_mmap_legacy_mem - map legacy PCI memory into user memory space
 * @filp: open sysfs file
 * @kobj: kobject corresponding to device to be mapped
 * @attr: struct bin_attribute for this file
 * @vma: struct vm_area_struct passed to mmap
 *
 * Uses an arch specific callback, pci_mmap_legacy_mem_page_range, to mmap
 * legacy memory space (first meg of bus space) into application virtual
 * memory space.
 */
static int pci_mmap_legacy_mem(struct file *filp, struct kobject *kobj,
                               const struct bin_attribute *attr,
                               struct vm_area_struct *vma)
{
        struct pci_bus *bus = to_pci_bus(kobj_to_dev(kobj));

        return pci_mmap_legacy_page_range(bus, vma, pci_mmap_mem);
}

/**
 * pci_mmap_legacy_io - map legacy PCI IO into user memory space
 * @filp: open sysfs file
 * @kobj: kobject corresponding to device to be mapped
 * @attr: struct bin_attribute for this file
 * @vma: struct vm_area_struct passed to mmap
 *
 * Uses an arch specific callback, pci_mmap_legacy_io_page_range, to mmap
 * legacy IO space (first meg of bus space) into application virtual
 * memory space. Returns -ENOSYS if the operation isn't supported
 */
static int pci_mmap_legacy_io(struct file *filp, struct kobject *kobj,
                              const struct bin_attribute *attr,
                              struct vm_area_struct *vma)
{
        struct pci_bus *bus = to_pci_bus(kobj_to_dev(kobj));

        return pci_mmap_legacy_page_range(bus, vma, pci_mmap_io);
}

bool __weak pci_legacy_has_sparse(struct pci_bus *bus,
                                  enum pci_mmap_state type)
{
        return false;
}

static inline umode_t __pci_legacy_is_visible(struct kobject *kobj,
                                              const struct bin_attribute *a,
                                              enum pci_mmap_state type,
                                              bool sparse)
{
        struct pci_bus *bus = to_pci_bus(kobj_to_dev(kobj));

        if (pci_legacy_has_sparse(bus, type) != sparse)
                return 0;

        return a->attr.mode;
}

static umode_t pci_legacy_io_is_visible(struct kobject *kobj,
                                        const struct bin_attribute *a, int n)
{
        return __pci_legacy_is_visible(kobj, a, pci_mmap_io, false);
}

static umode_t pci_legacy_io_sparse_is_visible(struct kobject *kobj,
                                               const struct bin_attribute *a,
                                               int n)
{
        return __pci_legacy_is_visible(kobj, a, pci_mmap_io, true);
}

static umode_t pci_legacy_mem_is_visible(struct kobject *kobj,
                                         const struct bin_attribute *a, int n)
{
        return __pci_legacy_is_visible(kobj, a, pci_mmap_mem, false);
}

static umode_t pci_legacy_mem_sparse_is_visible(struct kobject *kobj,
                                                const struct bin_attribute *a,
                                                int n)
{
        return __pci_legacy_is_visible(kobj, a, pci_mmap_mem, true);
}

static loff_t pci_llseek_resource_legacy(struct file *filep,
                                         struct kobject *kobj __always_unused,
                                         const struct bin_attribute *attr,
                                         loff_t offset, int whence)
{
        return fixed_size_llseek(filep, offset, whence, attr->size);
}

static const struct bin_attribute pci_legacy_io_attr = {
        .attr = { .name = "legacy_io", .mode = 0600 },
        .size = PCI_LEGACY_IO_SIZE,
        .read = pci_read_legacy_io,
        .write = pci_write_legacy_io,
        .mmap = pci_mmap_legacy_io,
        .llseek = pci_llseek_resource_legacy,
        .f_mapping = iomem_get_mapping,
};

static const struct bin_attribute pci_legacy_io_sparse_attr = {
        .attr = { .name = "legacy_io_sparse", .mode = 0600 },
        .size = PCI_LEGACY_IO_SIZE << 5,
        .read = pci_read_legacy_io,
        .write = pci_write_legacy_io,
        .mmap = pci_mmap_legacy_io,
        .llseek = pci_llseek_resource_legacy,
        .f_mapping = iomem_get_mapping,
};

static const struct bin_attribute pci_legacy_mem_attr = {
        .attr = { .name = "legacy_mem", .mode = 0600 },
        .size = PCI_LEGACY_MEM_SIZE,
        .mmap = pci_mmap_legacy_mem,
        .llseek = pci_llseek_resource_legacy,
        .f_mapping = iomem_get_mapping,
};

static const struct bin_attribute pci_legacy_mem_sparse_attr = {
        .attr = { .name = "legacy_mem_sparse", .mode = 0600 },
        .size = PCI_LEGACY_MEM_SIZE << 5,
        .mmap = pci_mmap_legacy_mem,
        .llseek = pci_llseek_resource_legacy,
        .f_mapping = iomem_get_mapping,
};

static const struct bin_attribute *const pci_legacy_io_attrs[] = {
        &pci_legacy_io_attr,
        NULL,
};

static const struct bin_attribute *const pci_legacy_io_sparse_attrs[] = {
        &pci_legacy_io_sparse_attr,
        NULL,
};

static const struct bin_attribute *const pci_legacy_mem_attrs[] = {
        &pci_legacy_mem_attr,
        NULL,
};

static const struct bin_attribute *const pci_legacy_mem_sparse_attrs[] = {
        &pci_legacy_mem_sparse_attr,
        NULL,
};

static const struct attribute_group pci_legacy_io_group = {
        .bin_attrs = pci_legacy_io_attrs,
        .is_bin_visible = pci_legacy_io_is_visible,
};

static const struct attribute_group pci_legacy_io_sparse_group = {
        .bin_attrs = pci_legacy_io_sparse_attrs,
        .is_bin_visible = pci_legacy_io_sparse_is_visible,
};

static const struct attribute_group pci_legacy_mem_group = {
        .bin_attrs = pci_legacy_mem_attrs,
        .is_bin_visible = pci_legacy_mem_is_visible,
};

static const struct attribute_group pci_legacy_mem_sparse_group = {
        .bin_attrs = pci_legacy_mem_sparse_attrs,
        .is_bin_visible = pci_legacy_mem_sparse_is_visible,
};

#endif /* HAVE_PCI_LEGACY */

const struct attribute_group *pcibus_groups[] = {
        &pcibus_group,
#ifdef HAVE_PCI_LEGACY
        &pci_legacy_io_group,
        &pci_legacy_io_sparse_group,
        &pci_legacy_mem_group,
        &pci_legacy_mem_sparse_group,
#endif
        NULL,
};

#if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
/**
 * pci_mmap_resource - map a PCI resource into user memory space
 * @kobj: kobject for mapping
 * @attr: struct bin_attribute for the file being mapped
 * @vma: struct vm_area_struct passed into the mmap
 * @write_combine: 1 for write_combine mapping
 *
 * Use the regular PCI mapping routines to map a PCI resource into userspace.
 */
static int pci_mmap_resource(struct kobject *kobj, const struct bin_attribute *attr,
                             struct vm_area_struct *vma, int write_combine)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
        int bar = (unsigned long)attr->private;
        enum pci_mmap_state mmap_type;
        int ret;

        ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
        if (ret)
                return ret;

        if (!pci_resource_is_mem(pdev, bar) &&
            !(pci_resource_is_io(pdev, bar) && arch_can_pci_mmap_io()))
                return -EIO;

        if (pci_resource_is_mem(pdev, bar) &&
            iomem_is_exclusive(pci_resource_start(pdev, bar)))
                return -EINVAL;

        if (!pci_mmap_fits(pdev, bar, vma, PCI_MMAP_SYSFS))
                return -EINVAL;

        mmap_type = pci_resource_is_mem(pdev, bar) ? pci_mmap_mem : pci_mmap_io;

        return pci_mmap_resource_range(pdev, bar, vma, mmap_type, write_combine);
}

static int pci_mmap_resource_uc(struct file *filp, struct kobject *kobj,
                                const 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,
                                const 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,
                               const struct bin_attribute *attr, char *buf,
                               loff_t off, size_t count, bool write)
{
#ifdef CONFIG_HAS_IOPORT
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
        int bar = (unsigned long)attr->private;
        unsigned long port = off;

        if (!pci_resource_is_io(pdev, bar))
                return -EIO;

        port += pci_resource_start(pdev, bar);

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

        if (port + count - 1 > pci_resource_end(pdev, bar))
                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;
#else
        return -ENXIO;
#endif
}

static ssize_t pci_read_resource(struct file *filp, struct kobject *kobj,
                                    const 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(struct file *filp, struct kobject *kobj,
                                     const struct bin_attribute *attr, char *buf,
                                     loff_t off, size_t count)
{
        int ret;

        ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
        if (ret)
                return ret;

        return pci_resource_io(filp, kobj, attr, buf, off, count, true);
}

static loff_t pci_llseek_resource(struct file *filep,
                                  struct kobject *kobj,
                                  const struct bin_attribute *attr,
                                  loff_t offset, int whence)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
        int bar = (unsigned long)attr->private;

        return fixed_size_llseek(filep, offset, whence,
                                 pci_resource_len(pdev, bar));
}

/*
 * generic_file_llseek() consults f_mapping->host to determine
 * the file size. As iomem_inode knows nothing about the
 * attribute, it's not going to work, so override it as well.
 */
#if arch_can_pci_mmap_io()
# define __PCI_RESOURCE_IO_MMAP_ATTRS           \
        .f_mapping = iomem_get_mapping,         \
        .llseek = pci_llseek_resource,          \
        .mmap = pci_mmap_resource_uc,
#else
# define __PCI_RESOURCE_IO_MMAP_ATTRS
#endif

#define pci_dev_resource_io_attr(_bar)                                  \
static const struct bin_attribute dev_resource##_bar##_io_attr = {      \
        .attr = { .name = "resource" __stringify(_bar), .mode = 0600 }, \
        .private = (void *)(unsigned long)(_bar),                       \
        .read = pci_read_resource,                                      \
        .write = pci_write_resource,                                    \
        __PCI_RESOURCE_IO_MMAP_ATTRS                                    \
}

#define pci_dev_resource_uc_attr(_bar)                                  \
static const struct bin_attribute dev_resource##_bar##_uc_attr = {      \
        .attr = { .name = "resource" __stringify(_bar), .mode = 0600 }, \
        .private = (void *)(unsigned long)(_bar),                       \
        .f_mapping = iomem_get_mapping,                                 \
        .llseek = pci_llseek_resource,                                  \
        .mmap = pci_mmap_resource_uc,                                   \
}

#define pci_dev_resource_wc_attr(_bar)                                        \
static const struct bin_attribute dev_resource##_bar##_wc_attr = {            \
        .attr = { .name = "resource" __stringify(_bar) "_wc", .mode = 0600 }, \
        .private = (void *)(unsigned long)(_bar),                             \
        .f_mapping = iomem_get_mapping,                                       \
        .llseek = pci_llseek_resource,                                        \
        .mmap = pci_mmap_resource_wc,                                         \
}

static inline umode_t
__pci_resource_attr_is_visible(struct kobject *kobj,
                               const struct bin_attribute *a,
                               int bar, bool write_combine,
                               unsigned long flags)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));

        if (pdev->non_mappable_bars)
                return 0;

        if (!pci_resource_len(pdev, bar))
                return 0;

        if ((pci_resource_flags(pdev, bar) & flags) != flags)
                return 0;

        if (write_combine && !arch_can_pci_mmap_wc())
                return 0;

        return a->attr.mode;
}

static umode_t pci_dev_resource_io_is_visible(struct kobject *kobj,
                                              const struct bin_attribute *a,
                                              int n)
{
        return __pci_resource_attr_is_visible(kobj, a, n, false,
                                              IORESOURCE_IO);
}

static umode_t pci_dev_resource_uc_is_visible(struct kobject *kobj,
                                              const struct bin_attribute *a,
                                              int n)
{
        return __pci_resource_attr_is_visible(kobj, a, n, false,
                                              IORESOURCE_MEM);
}

static umode_t pci_dev_resource_wc_is_visible(struct kobject *kobj,
                                              const struct bin_attribute *a,
                                              int n)
{
        return __pci_resource_attr_is_visible(kobj, a, n, true,
                                              IORESOURCE_MEM | IORESOURCE_PREFETCH);
}

static size_t pci_dev_resource_bin_size(struct kobject *kobj,
                                        const struct bin_attribute *a,
                                        int n)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));

        return pci_resource_len(pdev, n);
}

pci_dev_resource_io_attr(0);
pci_dev_resource_io_attr(1);
pci_dev_resource_io_attr(2);
pci_dev_resource_io_attr(3);
pci_dev_resource_io_attr(4);
pci_dev_resource_io_attr(5);

pci_dev_resource_uc_attr(0);
pci_dev_resource_uc_attr(1);
pci_dev_resource_uc_attr(2);
pci_dev_resource_uc_attr(3);
pci_dev_resource_uc_attr(4);
pci_dev_resource_uc_attr(5);

pci_dev_resource_wc_attr(0);
pci_dev_resource_wc_attr(1);
pci_dev_resource_wc_attr(2);
pci_dev_resource_wc_attr(3);
pci_dev_resource_wc_attr(4);
pci_dev_resource_wc_attr(5);

static const struct bin_attribute *const pci_dev_resource_io_attrs[] = {
        &dev_resource0_io_attr,
        &dev_resource1_io_attr,
        &dev_resource2_io_attr,
        &dev_resource3_io_attr,
        &dev_resource4_io_attr,
        &dev_resource5_io_attr,
        NULL,
};

static const struct bin_attribute *const pci_dev_resource_uc_attrs[] = {
        &dev_resource0_uc_attr,
        &dev_resource1_uc_attr,
        &dev_resource2_uc_attr,
        &dev_resource3_uc_attr,
        &dev_resource4_uc_attr,
        &dev_resource5_uc_attr,
        NULL,
};

static const struct bin_attribute *const pci_dev_resource_wc_attrs[] = {
        &dev_resource0_wc_attr,
        &dev_resource1_wc_attr,
        &dev_resource2_wc_attr,
        &dev_resource3_wc_attr,
        &dev_resource4_wc_attr,
        &dev_resource5_wc_attr,
        NULL,
};

static const struct attribute_group pci_dev_resource_io_attr_group = {
        .bin_attrs = pci_dev_resource_io_attrs,
        .is_bin_visible = pci_dev_resource_io_is_visible,
        .bin_size = pci_dev_resource_bin_size,
};

static const struct attribute_group pci_dev_resource_uc_attr_group = {
        .bin_attrs = pci_dev_resource_uc_attrs,
        .is_bin_visible = pci_dev_resource_uc_is_visible,
        .bin_size = pci_dev_resource_bin_size,
};

static const struct attribute_group pci_dev_resource_wc_attr_group = {
        .bin_attrs = pci_dev_resource_wc_attrs,
        .is_bin_visible = pci_dev_resource_wc_is_visible,
        .bin_size = pci_dev_resource_bin_size,
};

static const struct attribute_group *pci_dev_resource_attr_groups[] = {
        &pci_dev_resource_io_attr_group,
        &pci_dev_resource_uc_attr_group,
        &pci_dev_resource_wc_attr_group,
        NULL,
};
#else
#define pci_dev_resource_attr_groups NULL
#endif

/**
 * pci_write_rom - used to enable access to the PCI ROM display
 * @filp: sysfs file
 * @kobj: kernel object handle
 * @bin_attr: struct bin_attribute for this file
 * @buf: user input
 * @off: file offset
 * @count: number of byte in input
 *
 * Writing a boolean value enables or disables the ROM display.
 */
static ssize_t pci_write_rom(struct file *filp, struct kobject *kobj,
                             const struct bin_attribute *bin_attr, char *buf,
                             loff_t off, size_t count)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
        bool enable;

        if (kstrtobool(buf, &enable))
                return -EINVAL;

        pdev->rom_attr_enabled = enable;

        return count;
}

/**
 * pci_read_rom - read a PCI ROM
 * @filp: sysfs file
 * @kobj: kernel object handle
 * @bin_attr: struct bin_attribute for this file
 * @buf: where to put the data we read from the ROM
 * @off: file offset
 * @count: number of bytes to read
 *
 * Put @count bytes starting at @off into @buf from the ROM in the PCI
 * device corresponding to @kobj.
 */
static ssize_t pci_read_rom(struct file *filp, struct kobject *kobj,
                            const struct bin_attribute *bin_attr, char *buf,
                            loff_t off, size_t count)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(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 const BIN_ATTR(rom, 0600, pci_read_rom, pci_write_rom, 0);

static const struct bin_attribute *const pci_dev_rom_attrs[] = {
        &bin_attr_rom,
        NULL,
};

static umode_t pci_dev_rom_attr_is_visible(struct kobject *kobj,
                                           const struct bin_attribute *a, int n)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));

        /* If the device has a ROM, try to expose it in sysfs. */
        if (!pci_resource_end(pdev, PCI_ROM_RESOURCE))
                return 0;

        return a->attr.mode;
}

static size_t pci_dev_rom_attr_bin_size(struct kobject *kobj,
                                        const struct bin_attribute *a, int n)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));

        return pci_resource_len(pdev, PCI_ROM_RESOURCE);
}

static const struct attribute_group pci_dev_rom_attr_group = {
        .bin_attrs = pci_dev_rom_attrs,
        .is_bin_visible = pci_dev_rom_attr_is_visible,
        .bin_size = pci_dev_rom_attr_bin_size,
};

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;

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

        if (val != 1)
                return -EINVAL;

        pm_runtime_get_sync(dev);
        result = pci_reset_function(pdev);
        pm_runtime_put(dev);
        if (result < 0)
                return result;

        return count;
}
static DEVICE_ATTR_WO(reset);

static struct attribute *pci_dev_reset_attrs[] = {
        &dev_attr_reset.attr,
        NULL,
};

static umode_t pci_dev_reset_attr_is_visible(struct kobject *kobj,
                                             struct attribute *a, int n)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));

        if (!pci_reset_supported(pdev))
                return 0;

        return a->mode;
}

static const struct attribute_group pci_dev_reset_attr_group = {
        .attrs = pci_dev_reset_attrs,
        .is_visible = pci_dev_reset_attr_is_visible,
};

static ssize_t reset_method_show(struct device *dev,
                                 struct device_attribute *attr, char *buf)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        ssize_t len = 0;
        int i, m;

        for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
                m = pdev->reset_methods[i];
                if (!m)
                        break;

                len += sysfs_emit_at(buf, len, "%s%s", len ? " " : "",
                                     pci_reset_fn_methods[m].name);
        }

        if (len)
                len += sysfs_emit_at(buf, len, "\n");

        return len;
}

static int reset_method_lookup(const char *name)
{
        int m;

        for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
                if (sysfs_streq(name, pci_reset_fn_methods[m].name))
                        return m;
        }

        return 0;       /* not found */
}

static ssize_t reset_method_store(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, size_t count)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        char *tmp_options, *name;
        int m, n;
        u8 reset_methods[PCI_NUM_RESET_METHODS] = {};

        if (sysfs_streq(buf, "")) {
                pdev->reset_methods[0] = 0;
                pci_warn(pdev, "All device reset methods disabled by user");
                return count;
        }

        PM_RUNTIME_ACQUIRE(dev, pm);
        if (PM_RUNTIME_ACQUIRE_ERR(&pm))
                return -ENXIO;

        if (sysfs_streq(buf, "default")) {
                pci_init_reset_methods(pdev);
                return count;
        }

        char *options __free(kfree) = kstrndup(buf, count, GFP_KERNEL);
        if (!options)
                return -ENOMEM;

        n = 0;
        tmp_options = options;
        while ((name = strsep(&tmp_options, " ")) != NULL) {
                if (sysfs_streq(name, ""))
                        continue;

                name = strim(name);

                /* Leave previous methods unchanged if input is invalid */
                m = reset_method_lookup(name);
                if (!m) {
                        pci_err(pdev, "Invalid reset method '%s'", name);
                        return -EINVAL;
                }

                if (pci_reset_fn_methods[m].reset_fn(pdev, PCI_RESET_PROBE)) {
                        pci_err(pdev, "Unsupported reset method '%s'", name);
                        return -EINVAL;
                }

                if (n == PCI_NUM_RESET_METHODS - 1) {
                        pci_err(pdev, "Too many reset methods\n");
                        return -EINVAL;
                }

                reset_methods[n++] = m;
        }

        reset_methods[n] = 0;

        /* Warn if dev-specific supported but not highest priority */
        if (pci_reset_fn_methods[1].reset_fn(pdev, PCI_RESET_PROBE) == 0 &&
            reset_methods[0] != 1)
                pci_warn(pdev, "Device-specific reset disabled/de-prioritized by user");
        memcpy(pdev->reset_methods, reset_methods, sizeof(pdev->reset_methods));
        return count;
}
static DEVICE_ATTR_RW(reset_method);

static struct attribute *pci_dev_reset_method_attrs[] = {
        &dev_attr_reset_method.attr,
        NULL,
};

static const struct attribute_group pci_dev_reset_method_attr_group = {
        .attrs = pci_dev_reset_method_attrs,
        .is_visible = pci_dev_reset_attr_is_visible,
};

#if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
static ssize_t __resource_resize_show(struct device *dev, int n, char *buf)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        ssize_t ret;

        pci_config_pm_runtime_get(pdev);

        ret = sysfs_emit(buf, "%016llx\n",
                         pci_rebar_get_possible_sizes(pdev, n));

        pci_config_pm_runtime_put(pdev);

        return ret;
}

static ssize_t __resource_resize_store(struct device *dev, int n,
                                       const char *buf, size_t count)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        struct pci_bus *bus = pdev->bus;
        unsigned long size;
        int ret;
        u16 cmd;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        if (kstrtoul(buf, 0, &size) < 0)
                return -EINVAL;

        device_lock(dev);
        if (dev->driver || pci_num_vf(pdev)) {
                ret = -EBUSY;
                goto unlock;
        }

        pci_config_pm_runtime_get(pdev);

        if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA) {
                ret = aperture_remove_conflicting_pci_devices(pdev,
                                                "resourceN_resize");
                if (ret)
                        goto pm_put;
        }

        pci_read_config_word(pdev, PCI_COMMAND, &cmd);
        pci_write_config_word(pdev, PCI_COMMAND,
                              cmd & ~PCI_COMMAND_MEMORY);

        sysfs_remove_groups(&pdev->dev.kobj, pci_dev_resource_attr_groups);

        ret = pci_resize_resource(pdev, n, size, 0);
        if (ret)
                pci_warn(pdev, "Failed to resize BAR %d: %pe\n",
                         n, ERR_PTR(ret));

        pci_assign_unassigned_bus_resources(bus);

        if (sysfs_create_groups(&pdev->dev.kobj, pci_dev_resource_attr_groups))
                pci_warn(pdev, "Failed to recreate resource groups after BAR resizing\n");

        pci_write_config_word(pdev, PCI_COMMAND, cmd);
pm_put:
        pci_config_pm_runtime_put(pdev);
unlock:
        device_unlock(dev);

        return ret ? ret : count;
}

#define pci_dev_resource_resize_attr(n)                                 \
static ssize_t resource##n##_resize_show(struct device *dev,            \
                                         struct device_attribute *attr, \
                                         char *buf)                     \
{                                                                       \
        return __resource_resize_show(dev, n, buf);                     \
}                                                                       \
static ssize_t resource##n##_resize_store(struct device *dev,           \
                                          struct device_attribute *attr,\
                                          const char *buf, size_t count)\
{                                                                       \
        return __resource_resize_store(dev, n, buf, count);             \
}                                                                       \
static DEVICE_ATTR_RW(resource##n##_resize)

pci_dev_resource_resize_attr(0);
pci_dev_resource_resize_attr(1);
pci_dev_resource_resize_attr(2);
pci_dev_resource_resize_attr(3);
pci_dev_resource_resize_attr(4);
pci_dev_resource_resize_attr(5);

static struct attribute *resource_resize_attrs[] = {
        &dev_attr_resource0_resize.attr,
        &dev_attr_resource1_resize.attr,
        &dev_attr_resource2_resize.attr,
        &dev_attr_resource3_resize.attr,
        &dev_attr_resource4_resize.attr,
        &dev_attr_resource5_resize.attr,
        NULL,
};

static umode_t resource_resize_attr_is_visible(struct kobject *kobj,
                                          struct attribute *a, int n)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));

        return pci_rebar_get_current_size(pdev, n) < 0 ? 0 : a->mode;
}

static const struct attribute_group pci_dev_resource_resize_attr_group = {
        .attrs = resource_resize_attrs,
        .is_visible = resource_resize_attr_is_visible,
};
#endif

static struct attribute *pci_dev_dev_attrs[] = {
        &dev_attr_boot_vga.attr,
        &dev_attr_serial_number.attr,
        NULL,
};

static umode_t pci_dev_attrs_are_visible(struct kobject *kobj,
                                         struct attribute *a, int n)
{
        struct device *dev = kobj_to_dev(kobj);
        struct pci_dev *pdev = to_pci_dev(dev);

        if (a == &dev_attr_boot_vga.attr && pci_is_vga(pdev))
                return a->mode;

        if (a == &dev_attr_serial_number.attr && pci_get_dsn(pdev))
                return a->mode;

        return 0;
}

static struct attribute *pci_dev_hp_attrs[] = {
        &dev_attr_remove.attr,
        &dev_attr_dev_rescan.attr,
        NULL,
};

static umode_t pci_dev_hp_attrs_are_visible(struct kobject *kobj,
                                            struct attribute *a, int n)
{
        struct device *dev = kobj_to_dev(kobj);
        struct pci_dev *pdev = to_pci_dev(dev);

        if (pdev->is_virtfn)
                return 0;

        return a->mode;
}

static umode_t pci_bridge_attrs_are_visible(struct kobject *kobj,
                                            struct attribute *a, int n)
{
        struct device *dev = kobj_to_dev(kobj);
        struct pci_dev *pdev = to_pci_dev(dev);

        if (pci_is_bridge(pdev))
                return a->mode;

        return 0;
}

static umode_t pcie_dev_attrs_are_visible(struct kobject *kobj,
                                          struct attribute *a, int n)
{
        struct device *dev = kobj_to_dev(kobj);
        struct pci_dev *pdev = to_pci_dev(dev);

        if (pci_is_pcie(pdev))
                return a->mode;

        return 0;
}

static const struct attribute_group pci_dev_group = {
        .attrs = pci_dev_attrs,
};

const struct attribute_group *pci_dev_groups[] = {
        &pci_dev_group,
#if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
        &pci_dev_resource_io_attr_group,
        &pci_dev_resource_uc_attr_group,
        &pci_dev_resource_wc_attr_group,
        &pci_dev_resource_resize_attr_group,
#endif
        &pci_dev_config_attr_group,
        &pci_dev_rom_attr_group,
        &pci_dev_reset_attr_group,
        &pci_dev_reset_method_attr_group,
        &pci_dev_vpd_attr_group,
#ifdef CONFIG_DMI
        &pci_dev_smbios_attr_group,
#endif
#ifdef CONFIG_ACPI
        &pci_dev_acpi_attr_group,
#endif
        ARCH_PCI_DEV_GROUPS
        NULL,
};

static const struct attribute_group pci_dev_hp_attr_group = {
        .attrs = pci_dev_hp_attrs,
        .is_visible = pci_dev_hp_attrs_are_visible,
};

static const struct attribute_group pci_dev_attr_group = {
        .attrs = pci_dev_dev_attrs,
        .is_visible = pci_dev_attrs_are_visible,
};

static const struct attribute_group pci_bridge_attr_group = {
        .attrs = pci_bridge_attrs,
        .is_visible = pci_bridge_attrs_are_visible,
};

static const struct attribute_group pcie_dev_attr_group = {
        .attrs = pcie_dev_attrs,
        .is_visible = pcie_dev_attrs_are_visible,
};

const struct attribute_group *pci_dev_attr_groups[] = {
        &pci_dev_attr_group,
        &pci_dev_hp_attr_group,
#ifdef CONFIG_PCI_IOV
        &sriov_pf_dev_attr_group,
        &sriov_vf_dev_attr_group,
#endif
        &pci_bridge_attr_group,
        &pcie_dev_attr_group,
#ifdef CONFIG_PCIEAER
        &aer_stats_attr_group,
        &aer_attr_group,
#endif
#ifdef CONFIG_PCIEASPM
        &aspm_ctrl_attr_group,
#endif
#ifdef CONFIG_PCI_DOE
        &pci_doe_sysfs_group,
#endif
#ifdef CONFIG_PCI_TSM
        &pci_tsm_auth_attr_group,
        &pci_tsm_attr_group,
#endif
        NULL,
};