+/**
+ * pci_resource_bar - get position of the BAR associated with a resource
+ * @dev: the PCI device
+ * @resno: the resource number
+ * @type: the BAR type to be filled in
+ *
+ * Returns BAR position in config space, or 0 if the BAR is invalid.
+ */
+int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type)
+{
+ int reg;
+
+ if (resno < PCI_ROM_RESOURCE) {
+ *type = pci_bar_unknown;
+ return PCI_BASE_ADDRESS_0 + 4 * resno;
+ } else if (resno == PCI_ROM_RESOURCE) {
+ *type = pci_bar_mem32;
+ return dev->rom_base_reg;
+ } else if (resno < PCI_BRIDGE_RESOURCES) {
+ /* device specific resource */
+ reg = pci_iov_resource_bar(dev, resno, type);
+ if (reg)
+ return reg;
+ }
+
+ dev_err(&dev->dev, "BAR %d: invalid resource\n", resno);
+ return 0;
+}
+
+/**
+ * pci_set_vga_state - set VGA decode state on device and parents if requested
+ * @dev: the PCI device
+ * @decode: true = enable decoding, false = disable decoding
+ * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY
+ * @change_bridge: traverse ancestors and change bridges
+ */
+int pci_set_vga_state(struct pci_dev *dev, bool decode,
+ unsigned int command_bits, bool change_bridge)
+{
+ struct pci_bus *bus;
+ struct pci_dev *bridge;
+ u16 cmd;
+
+ WARN_ON(command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY));
+
+ pci_read_config_word(dev, PCI_COMMAND, &cmd);
+ if (decode == true)
+ cmd |= command_bits;
+ else
+ cmd &= ~command_bits;
+ pci_write_config_word(dev, PCI_COMMAND, cmd);
+
+ if (change_bridge == false)
+ return 0;
+
+ bus = dev->bus;
+ while (bus) {
+ bridge = bus->self;
+ if (bridge) {
+ pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
+ &cmd);
+ if (decode == true)
+ cmd |= PCI_BRIDGE_CTL_VGA;
+ else
+ cmd &= ~PCI_BRIDGE_CTL_VGA;
+ pci_write_config_word(bridge, PCI_BRIDGE_CONTROL,
+ cmd);
+ }
+ bus = bus->parent;
+ }
+ return 0;
+}
+
+#define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
+static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
+static DEFINE_SPINLOCK(resource_alignment_lock);
+
+/**
+ * pci_specified_resource_alignment - get resource alignment specified by user.
+ * @dev: the PCI device to get
+ *
+ * RETURNS: Resource alignment if it is specified.
+ * Zero if it is not specified.
+ */
+resource_size_t pci_specified_resource_alignment(struct pci_dev *dev)
+{
+ int seg, bus, slot, func, align_order, count;
+ resource_size_t align = 0;
+ char *p;
+
+ spin_lock(&resource_alignment_lock);
+ p = resource_alignment_param;
+ while (*p) {
+ count = 0;
+ if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
+ p[count] == '@') {
+ p += count + 1;
+ } else {
+ align_order = -1;
+ }
+ if (sscanf(p, "%x:%x:%x.%x%n",
+ &seg, &bus, &slot, &func, &count) != 4) {
+ seg = 0;
+ if (sscanf(p, "%x:%x.%x%n",
+ &bus, &slot, &func, &count) != 3) {
+ /* Invalid format */
+ printk(KERN_ERR "PCI: Can't parse resource_alignment parameter: %s\n",
+ p);
+ break;
+ }
+ }
+ p += count;
+ if (seg == pci_domain_nr(dev->bus) &&
+ bus == dev->bus->number &&
+ slot == PCI_SLOT(dev->devfn) &&
+ func == PCI_FUNC(dev->devfn)) {
+ if (align_order == -1) {
+ align = PAGE_SIZE;
+ } else {
+ align = 1 << align_order;
+ }
+ /* Found */
+ break;
+ }
+ if (*p != ';' && *p != ',') {
+ /* End of param or invalid format */
+ break;
+ }
+ p++;
+ }
+ spin_unlock(&resource_alignment_lock);
+ return align;
+}
+
+/**
+ * pci_is_reassigndev - check if specified PCI is target device to reassign
+ * @dev: the PCI device to check
+ *
+ * RETURNS: non-zero for PCI device is a target device to reassign,
+ * or zero is not.
+ */
+int pci_is_reassigndev(struct pci_dev *dev)
+{
+ return (pci_specified_resource_alignment(dev) != 0);
+}
+
+ssize_t pci_set_resource_alignment_param(const char *buf, size_t count)
+{
+ if (count > RESOURCE_ALIGNMENT_PARAM_SIZE - 1)
+ count = RESOURCE_ALIGNMENT_PARAM_SIZE - 1;
+ spin_lock(&resource_alignment_lock);
+ strncpy(resource_alignment_param, buf, count);
+ resource_alignment_param[count] = '\0';
+ spin_unlock(&resource_alignment_lock);
+ return count;
+}
+
+ssize_t pci_get_resource_alignment_param(char *buf, size_t size)
+{
+ size_t count;
+ spin_lock(&resource_alignment_lock);
+ count = snprintf(buf, size, "%s", resource_alignment_param);
+ spin_unlock(&resource_alignment_lock);
+ return count;
+}
+
+static ssize_t pci_resource_alignment_show(struct bus_type *bus, char *buf)
+{
+ return pci_get_resource_alignment_param(buf, PAGE_SIZE);
+}
+
+static ssize_t pci_resource_alignment_store(struct bus_type *bus,
+ const char *buf, size_t count)
+{
+ return pci_set_resource_alignment_param(buf, count);
+}
+
+BUS_ATTR(resource_alignment, 0644, pci_resource_alignment_show,
+ pci_resource_alignment_store);
+
+static int __init pci_resource_alignment_sysfs_init(void)
+{
+ return bus_create_file(&pci_bus_type,
+ &bus_attr_resource_alignment);
+}
+
+late_initcall(pci_resource_alignment_sysfs_init);
+