sparc/kernel/pci.c

// SPDX-License-Identifier: GPL-2.0
/* pci.c: UltraSparc PCI controller support.
 *
 * Copyright (C) 1997, 1998, 1999 David S. Miller (davem@redhat.com)
 * Copyright (C) 1998, 1999 Eddie C. Dost   (ecd@skynet.be)
 * Copyright (C) 1999 Jakub Jelinek   (jj@ultra.linux.cz)
 *
 * OF tree based PCI bus probing taken from the PowerPC port
 * with minor modifications, see there for credits.
 */

#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <linux/irq.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pgtable.h>

#include <linux/uaccess.h>
#include <asm/irq.h>
#include <asm/prom.h>
#include <asm/apb.h>

#include "pci_impl.h"
#include "kernel.h"

/* List of all PCI controllers found in the system. */
struct pci_pbm_info *pci_pbm_root = NULL;

/* Each PBM found gets a unique index. */
int pci_num_pbms = 0;

volatile int pci_poke_in_progress;
volatile int pci_poke_cpu = -1;
volatile int pci_poke_faulted;

static DEFINE_SPINLOCK(pci_poke_lock);

void pci_config_read8(u8 *addr, u8 *ret)
{
	unsigned long flags;
	u8 byte;

	spin_lock_irqsave(&pci_poke_lock, flags);
	pci_poke_cpu = smp_processor_id();
	pci_poke_in_progress = 1;
	pci_poke_faulted = 0;
	__asm__ __volatile__("membar #Sync\n\t"
			     "lduba [%1] %2, %0\n\t"
			     "membar #Sync"
			     : "=r" (byte)
			     : "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E_L)
			     : "memory");
	pci_poke_in_progress = 0;
	pci_poke_cpu = -1;
	if (!pci_poke_faulted)
		*ret = byte;
	spin_unlock_irqrestore(&pci_poke_lock, flags);
}

void pci_config_read16(u16 *addr, u16 *ret)
{
	unsigned long flags;
	u16 word;

	spin_lock_irqsave(&pci_poke_lock, flags);
	pci_poke_cpu = smp_processor_id();
	pci_poke_in_progress = 1;
	pci_poke_faulted = 0;
	__asm__ __volatile__("membar #Sync\n\t"
			     "lduha [%1] %2, %0\n\t"
			     "membar #Sync"
			     : "=r" (word)
			     : "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E_L)
			     : "memory");
	pci_poke_in_progress = 0;
	pci_poke_cpu = -1;
	if (!pci_poke_faulted)
		*ret = word;
	spin_unlock_irqrestore(&pci_poke_lock, flags);
}

void pci_config_read32(u32 *addr, u32 *ret)
{
	unsigned long flags;
	u32 dword;

	spin_lock_irqsave(&pci_poke_lock, flags);
	pci_poke_cpu = smp_processor_id();
	pci_poke_in_progress = 1;
	pci_poke_faulted = 0;
	__asm__ __volatile__("membar #Sync\n\t"
			     "lduwa [%1] %2, %0\n\t"
			     "membar #Sync"
			     : "=r" (dword)
			     : "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E_L)
			     : "memory");
	pci_poke_in_progress = 0;
	pci_poke_cpu = -1;
	if (!pci_poke_faulted)
		*ret = dword;
	spin_unlock_irqrestore(&pci_poke_lock, flags);
}

void pci_config_write8(u8 *addr, u8 val)
{
	unsigned long flags;

	spin_lock_irqsave(&pci_poke_lock, flags);
	pci_poke_cpu = smp_processor_id();
	pci_poke_in_progress = 1;
	pci_poke_faulted = 0;
	__asm__ __volatile__("membar #Sync\n\t"
			     "stba %0, [%1] %2\n\t"
			     "membar #Sync"
			     : /* no outputs */
			     : "r" (val), "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E_L)
			     : "memory");
	pci_poke_in_progress = 0;
	pci_poke_cpu = -1;
	spin_unlock_irqrestore(&pci_poke_lock, flags);
}

void pci_config_write16(u16 *addr, u16 val)
{
	unsigned long flags;

	spin_lock_irqsave(&pci_poke_lock, flags);
	pci_poke_cpu = smp_processor_id();
	pci_poke_in_progress = 1;
	pci_poke_faulted = 0;
	__asm__ __volatile__("membar #Sync\n\t"
			     "stha %0, [%1] %2\n\t"
			     "membar #Sync"
			     : /* no outputs */
			     : "r" (val), "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E_L)
			     : "memory");
	pci_poke_in_progress = 0;
	pci_poke_cpu = -1;
	spin_unlock_irqrestore(&pci_poke_lock, flags);
}

void pci_config_write32(u32 *addr, u32 val)
{
	unsigned long flags;

	spin_lock_irqsave(&pci_poke_lock, flags);
	pci_poke_cpu = smp_processor_id();
	pci_poke_in_progress = 1;
	pci_poke_faulted = 0;
	__asm__ __volatile__("membar #Sync\n\t"
			     "stwa %0, [%1] %2\n\t"
			     "membar #Sync"
			     : /* no outputs */
			     : "r" (val), "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E_L)
			     : "memory");
	pci_poke_in_progress = 0;
	pci_poke_cpu = -1;
	spin_unlock_irqrestore(&pci_poke_lock, flags);
}

static int ofpci_verbose;

static int __init ofpci_debug(char *str)
{
	int val = 0;

	get_option(&str, &val);
	if (val)
		ofpci_verbose = 1;
	return 1;
}

__setup("ofpci_debug=", ofpci_debug);

static unsigned long pci_parse_of_flags(u32 addr0)
{
	unsigned long flags = 0;

	if (addr0 & 0x02000000) {
		flags = IORESOURCE_MEM | PCI_BASE_ADDRESS_SPACE_MEMORY;
		flags |= (addr0 >> 28) & PCI_BASE_ADDRESS_MEM_TYPE_1M;
		if (addr0 & 0x01000000)
			flags |= IORESOURCE_MEM_64
				 | PCI_BASE_ADDRESS_MEM_TYPE_64;
		if (addr0 & 0x40000000)
			flags |= IORESOURCE_PREFETCH
				 | PCI_BASE_ADDRESS_MEM_PREFETCH;
	} else if (addr0 & 0x01000000)
		flags = IORESOURCE_IO | PCI_BASE_ADDRESS_SPACE_IO;
	return flags;
}

/* The of_device layer has translated all of the assigned-address properties
 * into physical address resources, we only have to figure out the register
 * mapping.
 */
static void pci_parse_of_addrs(struct platform_device *op,
			       struct device_node *node,
			       struct pci_dev *dev)
{
	struct resource *op_res;
	const u32 *addrs;
	int proplen;

	addrs = of_get_property(node, "assigned-addresses", &proplen);
	if (!addrs)
		return;
	if (ofpci_verbose)
		pci_info(dev, "    parse addresses (%d bytes) @ %p\n",
			 proplen, addrs);
	op_res = &op->resource[0];
	for (; proplen >= 20; proplen -= 20, addrs += 5, op_res++) {
		struct resource *res;
		unsigned long flags;
		int i;

		flags = pci_parse_of_flags(addrs[0]);
		if (!flags)
			continue;
		i = addrs[0] & 0xff;
		if (ofpci_verbose)
			pci_info(dev, "  start: %llx, end: %llx, i: %x\n",
				 op_res->start, op_res->end, i);

		if (PCI_BASE_ADDRESS_0 <= i && i <= PCI_BASE_ADDRESS_5) {
			res = &dev->resource[(i - PCI_BASE_ADDRESS_0) >> 2];
		} else if (i == dev->rom_base_reg) {
			res = &dev->resource[PCI_ROM_RESOURCE];
			flags |= IORESOURCE_READONLY | IORESOURCE_SIZEALIGN;
		} else {
			pci_err(dev, "bad cfg reg num 0x%x\n", i);
			continue;
		}
		res->start = op_res->start;
		res->end = op_res->end;
		res->flags = flags;
		res->name = pci_name(dev);

		pci_info(dev, "reg 0x%x: %pR\n", i, res);
	}
}

static void pci_init_dev_archdata(struct dev_archdata *sd, void *iommu,
				  void *stc, void *host_controller,
				  struct platform_device  *op,
				  int numa_node)
{
	sd->iommu = iommu;
	sd->stc = stc;
	sd->host_controller = host_controller;
	sd->op = op;
	sd->numa_node = numa_node;
}

static struct pci_dev *of_create_pci_dev(struct pci_pbm_info *pbm,
					 struct device_node *node,
					 struct pci_bus *bus, int devfn)
{
	struct dev_archdata *sd;
	struct platform_device *op;
	struct pci_dev *dev;
	u32 class;

	dev = pci_alloc_dev(bus);
	if (!dev)
		return NULL;

	op = of_find_device_by_node(node);
	sd = &dev->dev.archdata;
	pci_init_dev_archdata(sd, pbm->iommu, &pbm->stc, pbm, op,
			      pbm->numa_node);
	sd = &op->dev.archdata;
	sd->iommu = pbm->iommu;
	sd->stc = &pbm->stc;
	sd->numa_node = pbm->numa_node;

	if (of_node_name_eq(node, "ebus"))
		of_propagate_archdata(op);

	if (ofpci_verbose)
		pci_info(bus,"    create device, devfn: %x, type: %s\n",
			 devfn, of_node_get_device_type(node));

	dev->sysdata = node;
	dev->dev.parent = bus->bridge;
	dev->dev.bus = &pci_bus_type;
	dev->dev.of_node = of_node_get(node);
	dev->devfn = devfn;
	dev->multifunction = 0;		/* maybe a lie? */
	set_pcie_port_type(dev);

	pci_dev_assign_slot(dev);
	dev->vendor = of_getintprop_default(node, "vendor-id", 0xffff);
	dev->device = of_getintprop_default(node, "device-id", 0xffff);
	dev->subsystem_vendor =
		of_getintprop_default(node, "subsystem-vendor-id", 0);
	dev->subsystem_device =
		of_getintprop_default(node, "subsystem-id", 0);

	dev->cfg_size = pci_cfg_space_size(dev);

	/* We can't actually use the firmware value, we have
	 * to read what is in the register right now.  One
	 * reason is that in the case of IDE interfaces the
	 * firmware can sample the value before the the IDE
	 * interface is programmed into native mode.
	 */
	pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
	dev->class = class >> 8;
	dev->revision = class & 0xff;

	dev_set_name(&dev->dev, "%04x:%02x:%02x.%d", pci_domain_nr(bus),
		dev->bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn));

	/* I have seen IDE devices which will not respond to
	 * the bmdma simplex check reads if bus mastering is
	 * disabled.
	 */
	if ((dev->class >> 8) == PCI_CLASS_STORAGE_IDE)
		pci_set_master(dev);

	dev->current_state = PCI_UNKNOWN;	/* unknown power state */
	dev->error_state = pci_channel_io_normal;
	dev->dma_mask = 0xffffffff;

	if (of_node_name_eq(node, "pci")) {
		/* a PCI-PCI bridge */
		dev->hdr_type = PCI_HEADER_TYPE_BRIDGE;
		dev->rom_base_reg = PCI_ROM_ADDRESS1;
	} else if (of_node_is_type(node, "cardbus")) {
		dev->hdr_type = PCI_HEADER_TYPE_CARDBUS;
	} else {
		dev->hdr_type = PCI_HEADER_TYPE_NORMAL;
		dev->rom_base_reg = PCI_ROM_ADDRESS;

		dev->irq = sd->op->archdata.irqs[0];
		if (dev->irq == 0xffffffff)
			dev->irq = PCI_IRQ_NONE;
	}

	pci_info(dev, "[%04x:%04x] type %02x class %#08x\n",
		 dev->vendor, dev->device, dev->hdr_type, dev->class);

	pci_parse_of_addrs(sd->op, node, dev);

	if (ofpci_verbose)
		pci_info(dev, "    adding to system ...\n");

	pci_device_add(dev, bus);

	return dev;
}

static void apb_calc_first_last(u8 map, u32 *first_p, u32 *last_p)
{
	u32 idx, first, last;

	first = 8;
	last = 0;
	for (idx = 0; idx < 8; idx++) {
		if ((map & (1 << idx)) != 0) {
			if (first > idx)
				first = idx;
			if (last < idx)
				last = idx;
		}
	}

	*first_p = first;
	*last_p = last;
}

/* Cook up fake bus resources for SUNW,simba PCI bridges which lack
 * a proper 'ranges' property.
 */
static void apb_fake_ranges(struct pci_dev *dev,
			    struct pci_bus *bus,
			    struct pci_pbm_info *pbm)
{
	struct pci_bus_region region;
	struct resource *res;
	u32 first, last;
	u8 map;

	pci_read_config_byte(dev, APB_IO_ADDRESS_MAP, &map);
	apb_calc_first_last(map, &first, &last);
	res = bus->resource[0];
	res->flags = IORESOURCE_IO;
	region.start = (first << 21);
	region.end = (last << 21) + ((1 << 21) - 1);
	pcibios_bus_to_resource(dev->bus, res, &region);

	pci_read_config_byte(dev, APB_MEM_ADDRESS_MAP, &map);
	apb_calc_first_last(map, &first, &last);
	res = bus->resource[1];
	res->flags = IORESOURCE_MEM;
	region.start = (first << 29);
	region.end = (last << 29) + ((1 << 29) - 1);
	pcibios_bus_to_resource(dev->bus, res, &region);
}

static void pci_of_scan_bus(struct pci_pbm_info *pbm,
			    struct device_node *node,
			    struct pci_bus *bus);

#define GET_64BIT(prop, i)	((((u64) (prop)[(i)]) << 32) | (prop)[(i)+1])

static void of_scan_pci_bridge(struct pci_pbm_info *pbm,
			       struct device_node *node,
			       struct pci_dev *dev)
{
	struct pci_bus *bus;
	const u32 *busrange, *ranges;
	int len, i, simba;
	struct pci_bus_region region;
	struct resource *res;
	unsigned int flags;
	u64 size;

	if (ofpci_verbose)
		pci_info(dev, "of_scan_pci_bridge(%pOF)\n", node);

	/* parse bus-range property */
	busrange = of_get_property(node, "bus-range", &len);
	if (busrange == NULL || len != 8) {
		pci_info(dev, "Can't get bus-range for PCI-PCI bridge %pOF\n",
		       node);
		return;
	}

	if (ofpci_verbose)
		pci_info(dev, "    Bridge bus range [%u --> %u]\n",
			 busrange[0], busrange[1]);

	ranges = of_get_property(node, "ranges", &len);
	simba = 0;
	if (ranges == NULL) {
		const char *model = of_get_property(node, "model", NULL);
		if (model && !strcmp(model, "SUNW,simba"))
			simba = 1;
	}

	bus = pci_add_new_bus(dev->bus, dev, busrange[0]);
	if (!bus) {
		pci_err(dev, "Failed to create pci bus for %pOF\n",
			node);
		return;
	}

	bus->primary = dev->bus->number;
	pci_bus_insert_busn_res(bus, busrange[0], busrange[1]);
	bus->bridge_ctl = 0;

	if (ofpci_verbose)
		pci_info(dev, "    Bridge ranges[%p] simba[%d]\n",
			 ranges, simba);

	/* parse ranges property, or cook one up by hand for Simba */
	/* PCI #address-cells == 3 and #size-cells == 2 always */
	res = &dev->resource[PCI_BRIDGE_RESOURCES];
	for (i = 0; i < PCI_NUM_RESOURCES - PCI_BRIDGE_RESOURCES; ++i) {
		res->flags = 0;
		bus->resource[i] = res;
		++res;
	}
	if (simba) {
		apb_fake_ranges(dev, bus, pbm);
		goto after_ranges;
	} else if (ranges == NULL) {
		pci_read_bridge_bases(bus);
		goto after_ranges;
	}
	i = 1;
	for (; len >= 32; len -= 32, ranges += 8) {
		u64 start;

		if (ofpci_verbose)
			pci_info(dev, "    RAW Range[%08x:%08x:%08x:%08x:%08x:%08x:"
				 "%08x:%08x]\n",
				 ranges[0], ranges[1], ranges[2], ranges[3],
				 ranges[4], ranges[5], ranges[6], ranges[7]);

		flags = pci_parse_of_flags(ranges[0]);
		size = GET_64BIT(ranges, 6);
		if (flags == 0 || size == 0)
			continue;

		/* On PCI-Express systems, PCI bridges that have no devices downstream
		 * have a bogus size value where the first 32-bit cell is 0xffffffff.
		 * This results in a bogus range where start + size overflows.
		 *
		 * Just skip these otherwise the kernel will complain when the resource
		 * tries to be claimed.
		 */
		if (size >> 32 == 0xffffffff)
			continue;

		if (flags & IORESOURCE_IO) {
			res = bus->resource[0];
			if (res->flags) {
				pci_err(dev, "ignoring extra I/O range"
					" for bridge %pOF\n", node);
				continue;
			}
		} else {
			if (i >= PCI_NUM_RESOURCES - PCI_BRIDGE_RESOURCES) {
				pci_err(dev, "too many memory ranges"
					" for bridge %pOF\n", node);
				continue;
			}
			res = bus->resource[i];
			++i;
		}

		res->flags = flags;
		region.start = start = GET_64BIT(ranges, 1);
		region.end = region.start + size - 1;

		if (ofpci_verbose)
			pci_info(dev, "      Using flags[%08x] start[%016llx] size[%016llx]\n",
				 flags, start, size);

		pcibios_bus_to_resource(dev->bus, res, &region);
	}
after_ranges:
	sprintf(bus->name, "PCI Bus %04x:%02x", pci_domain_nr(bus),
		bus->number);
	if (ofpci_verbose)
		pci_info(dev, "    bus name: %s\n", bus->name);

	pci_of_scan_bus(pbm, node, bus);
}

static void pci_of_scan_bus(struct pci_pbm_info *pbm,
			    struct device_node *node,
			    struct pci_bus *bus)
{
	struct device_node *child;
	const u32 *reg;
	int reglen, devfn, prev_devfn;
	struct pci_dev *dev;

	if (ofpci_verbose)
		pci_info(bus, "scan_bus[%pOF] bus no %d\n",
			 node, bus->number);

	child = NULL;
	prev_devfn = -1;
	while ((child = of_get_next_child(node, child)) != NULL) {
		if (ofpci_verbose)
			pci_info(bus, "  * %pOF\n", child);
		reg = of_get_property(child, "reg", &reglen);
		if (reg == NULL || reglen < 20)
			continue;

		devfn = (reg[0] >> 8) & 0xff;

		/* This is a workaround for some device trees
		 * which list PCI devices twice.  On the V100
		 * for example, device number 3 is listed twice.
		 * Once as "pm" and once again as "lomp".
		 */
		if (devfn == prev_devfn)
			continue;
		prev_devfn = devfn;

		/* create a new pci_dev for this device */
		dev = of_create_pci_dev(pbm, child, bus, devfn);
		if (!dev)
			continue;
		if (ofpci_verbose)
			pci_info(dev, "dev header type: %x\n", dev->hdr_type);

		if (pci_is_bridge(dev))
			of_scan_pci_bridge(pbm, child, dev);
	}
}

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

	pdev = to_pci_dev(dev);
	dp = pdev->dev.of_node;

	return scnprintf(buf, PAGE_SIZE, "%pOF\n", dp);
}

static DEVICE_ATTR(obppath, S_IRUSR | S_IRGRP | S_IROTH, show_pciobppath_attr, NULL);

static void pci_bus_register_of_sysfs(struct pci_bus *bus)
{
	struct pci_dev *dev;
	struct pci_bus *child_bus;
	int err;

	list_for_each_entry(dev, &bus->devices, bus_list) {
		/* we don't really care if we can create this file or
		 * not, but we need to assign the result of the call
		 * or the world will fall under alien invasion and
		 * everybody will be frozen on a spaceship ready to be
		 * eaten on alpha centauri by some green and jelly
		 * humanoid.
		 */
		err = sysfs_create_file(&dev->dev.kobj, &dev_attr_obppath.attr);
		(void) err;
	}
	list_for_each_entry(child_bus, &bus->children, node)
		pci_bus_register_of_sysfs(child_bus);
}

static void pci_claim_legacy_resources(struct pci_dev *dev)
{
	struct pci_bus_region region;
	struct resource *p, *root, *conflict;

	if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
		return;

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	if (!p)
		return;

	p->name = "Video RAM area";
	p->flags = IORESOURCE_MEM | IORESOURCE_BUSY;

	region.start = 0xa0000UL;
	region.end = region.start + 0x1ffffUL;
	pcibios_bus_to_resource(dev->bus, p, &region);

	root = pci_find_parent_resource(dev, p);
	if (!root) {
		pci_info(dev, "can't claim VGA legacy %pR: no compatible bridge window\n", p);
		goto err;
	}

	conflict = request_resource_conflict(root, p);
	if (conflict) {
		pci_info(dev, "can't claim VGA legacy %pR: address conflict with %s %pR\n",
			 p, conflict->name, conflict);
		goto err;
	}

	pci_info(dev, "VGA legacy framebuffer %pR\n", p);
	return;

err:
	kfree(p);
}

static void pci_claim_bus_resources(struct pci_bus *bus)
{
	struct pci_bus *child_bus;
	struct pci_dev *dev;

	list_for_each_entry(dev, &bus->devices, bus_list) {
		int i;

		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
			struct resource *r = &dev->resource[i];

			if (r->parent || !r->start || !r->flags)
				continue;

			if (ofpci_verbose)
				pci_info(dev, "Claiming Resource %d: %pR\n",
					 i, r);

			pci_claim_resource(dev, i);
		}

		pci_claim_legacy_resources(dev);
	}

	list_for_each_entry(child_bus, &bus->children, node)
		pci_claim_bus_resources(child_bus);
}

struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm,
				 struct device *parent)
{
	LIST_HEAD(resources);
	struct device_node *node = pbm->op->dev.of_node;
	struct pci_bus *bus;

	printk("PCI: Scanning PBM %pOF\n", node);

	pci_add_resource_offset(&resources, &pbm->io_space,
				pbm->io_offset);
	pci_add_resource_offset(&resources, &pbm->mem_space,
				pbm->mem_offset);
	if (pbm->mem64_space.flags)
		pci_add_resource_offset(&resources, &pbm->mem64_space,
					pbm->mem64_offset);
	pbm->busn.start = pbm->pci_first_busno;
	pbm->busn.end	= pbm->pci_last_busno;
	pbm->busn.flags	= IORESOURCE_BUS;
	pci_add_resource(&resources, &pbm->busn);
	bus = pci_create_root_bus(parent, pbm->pci_first_busno, pbm->pci_ops,
				  pbm, &resources);
	if (!bus) {
		printk(KERN_ERR "Failed to create bus for %pOF\n", node);
		pci_free_resource_list(&resources);
		return NULL;
	}

	pci_of_scan_bus(pbm, node, bus);
	pci_bus_register_of_sysfs(bus);

	pci_claim_bus_resources(bus);

	pci_bus_add_devices(bus);
	return bus;
}

int pcibios_enable_device(struct pci_dev *dev, int mask)
{
	u16 cmd, oldcmd;
	int i;

	pci_read_config_word(dev, PCI_COMMAND, &cmd);
	oldcmd = cmd;

	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
		struct resource *res = &dev->resource[i];

		/* Only set up the requested stuff */
		if (!(mask & (1<<i)))
			continue;

		if (res->flags & IORESOURCE_IO)
			cmd |= PCI_COMMAND_IO;
		if (res->flags & IORESOURCE_MEM)
			cmd |= PCI_COMMAND_MEMORY;
	}

	if (cmd != oldcmd) {
		pci_info(dev, "enabling device (%04x -> %04x)\n", oldcmd, cmd);
		pci_write_config_word(dev, PCI_COMMAND, cmd);
	}
	return 0;
}

/* Platform support for /proc/bus/pci/X/Y mmap()s. */

/* If the user uses a host-bridge as the PCI device, he may use
 * this to perform a raw mmap() of the I/O or MEM space behind
 * that controller.
 *
 * This can be useful for execution of x86 PCI bios initialization code
 * on a PCI card, like the xfree86 int10 stuff does.
 */
static int __pci_mmap_make_offset_bus(struct pci_dev *pdev, struct vm_area_struct *vma,
				      enum pci_mmap_state mmap_state)
{
	struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
	unsigned long space_size, user_offset, user_size;

	if (mmap_state == pci_mmap_io) {
		space_size = resource_size(&pbm->io_space);
	} else {
		space_size = resource_size(&pbm->mem_space);
	}

	/* Make sure the request is in range. */
	user_offset = vma->vm_pgoff << PAGE_SHIFT;
	user_size = vma->vm_end - vma->vm_start;

	if (user_offset >= space_size ||
	    (user_offset + user_size) > space_size)
		return -EINVAL;

	if (mmap_state == pci_mmap_io) {
		vma->vm_pgoff = (pbm->io_space.start +
				 user_offset) >> PAGE_SHIFT;
	} else {
		vma->vm_pgoff = (pbm->mem_space.start +
				 user_offset) >> PAGE_SHIFT;
	}

	return 0;
}

/* Adjust vm_pgoff of VMA such that it is the physical page offset
 * corresponding to the 32-bit pci bus offset for DEV requested by the user.
 *
 * Basically, the user finds the base address for his device which he wishes
 * to mmap.  They read the 32-bit value from the config space base register,
 * add whatever PAGE_SIZE multiple offset they wish, and feed this into the
 * offset parameter of mmap on /proc/bus/pci/XXX for that device.
 *
 * Returns negative error code on failure, zero on success.
 */
static int __pci_mmap_make_offset(struct pci_dev *pdev,
				  struct vm_area_struct *vma,
				  enum pci_mmap_state mmap_state)
{
	unsigned long user_paddr, user_size;
	int i, err;

	/* First compute the physical address in vma->vm_pgoff,
	 * making sure the user offset is within range in the
	 * appropriate PCI space.
	 */
	err = __pci_mmap_make_offset_bus(pdev, vma, mmap_state);
	if (err)
		return err;

	/* If this is a mapping on a host bridge, any address
	 * is OK.
	 */
	if ((pdev->class >> 8) == PCI_CLASS_BRIDGE_HOST)
		return err;

	/* Otherwise make sure it's in the range for one of the
	 * device's resources.
	 */
	user_paddr = vma->vm_pgoff << PAGE_SHIFT;
	user_size = vma->vm_end - vma->vm_start;

	for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
		struct resource *rp = &pdev->resource[i];
		resource_size_t aligned_end;

		/* Active? */
		if (!rp->flags)
			continue;

		/* Same type? */
		if (i == PCI_ROM_RESOURCE) {
			if (mmap_state != pci_mmap_mem)
				continue;
		} else {
			if ((mmap_state == pci_mmap_io &&
			     (rp->flags & IORESOURCE_IO) == 0) ||
			    (mmap_state == pci_mmap_mem &&
			     (rp->flags & IORESOURCE_MEM) == 0))
				continue;
		}

		/* Align the resource end to the next page address.
		 * PAGE_SIZE intentionally added instead of (PAGE_SIZE - 1),
		 * because actually we need the address of the next byte
		 * after rp->end.
		 */
		aligned_end = (rp->end + PAGE_SIZE) & PAGE_MASK;

		if ((rp->start <= user_paddr) &&
		    (user_paddr + user_size) <= aligned_end)
			break;
	}

	if (i > PCI_ROM_RESOURCE)
		return -EINVAL;

	return 0;
}

/* Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
 * device mapping.
 */
static void __pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vma,
					     enum pci_mmap_state mmap_state)
{
	/* Our io_remap_pfn_range takes care of this, do nothing.  */
}

/* Perform the actual remap of the pages for a PCI device mapping, as appropriate
 * for this architecture.  The region in the process to map is described by vm_start
 * and vm_end members of VMA, the base physical address is found in vm_pgoff.
 * The pci device structure is provided so that architectures may make mapping
 * decisions on a per-device or per-bus basis.
 *
 * Returns a negative error code on failure, zero on success.
 */
int pci_mmap_page_range(struct pci_dev *dev, int bar,
			struct vm_area_struct *vma,
			enum pci_mmap_state mmap_state, int write_combine)
{
	int ret;

	ret = __pci_mmap_make_offset(dev, vma, mmap_state);
	if (ret < 0)
		return ret;

	__pci_mmap_set_pgprot(dev, vma, mmap_state);

	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
	ret = io_remap_pfn_range(vma, vma->vm_start,
				 vma->vm_pgoff,
				 vma->vm_end - vma->vm_start,
				 vma->vm_page_prot);
	if (ret)
		return ret;

	return 0;
}

#ifdef CONFIG_NUMA
int pcibus_to_node(struct pci_bus *pbus)
{
	struct pci_pbm_info *pbm = pbus->sysdata;

	return pbm->numa_node;
}
EXPORT_SYMBOL(pcibus_to_node);
#endif

/* Return the domain number for this pci bus */

int pci_domain_nr(struct pci_bus *pbus)
{
	struct pci_pbm_info *pbm = pbus->sysdata;
	int ret;

	if (!pbm) {
		ret = -ENXIO;
	} else {
		ret = pbm->index;
	}

	return ret;
}
EXPORT_SYMBOL(pci_domain_nr);

#ifdef CONFIG_PCI_MSI
int arch_setup_msi_irq(struct pci_dev *pdev, struct msi_desc *desc)
{
	struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
	unsigned int irq;

	if (!pbm->setup_msi_irq)
		return -EINVAL;

	return pbm->setup_msi_irq(&irq, pdev, desc);
}

void arch_teardown_msi_irq(unsigned int irq)
{
	struct msi_desc *entry = irq_get_msi_desc(irq);
	struct pci_dev *pdev = msi_desc_to_pci_dev(entry);
	struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;

	if (pbm->teardown_msi_irq)
		pbm->teardown_msi_irq(irq, pdev);
}
#endif /* !(CONFIG_PCI_MSI) */

/* ALI sound chips generate 31-bits of DMA, a special register
 * determines what bit 31 is emitted as.
 */
int ali_sound_dma_hack(struct device *dev, u64 device_mask)
{
	struct iommu *iommu = dev->archdata.iommu;
	struct pci_dev *ali_isa_bridge;
	u8 val;

	if (!dev_is_pci(dev))
		return 0;

	if (to_pci_dev(dev)->vendor != PCI_VENDOR_ID_AL ||
	    to_pci_dev(dev)->device != PCI_DEVICE_ID_AL_M5451 ||
	    device_mask != 0x7fffffff)
		return 0;

	ali_isa_bridge = pci_get_device(PCI_VENDOR_ID_AL,
					 PCI_DEVICE_ID_AL_M1533,
					 NULL);

	pci_read_config_byte(ali_isa_bridge, 0x7e, &val);
	if (iommu->dma_addr_mask & 0x80000000)
		val |= 0x01;
	else
		val &= ~0x01;
	pci_write_config_byte(ali_isa_bridge, 0x7e, val);
	pci_dev_put(ali_isa_bridge);
	return 1;
}

void pci_resource_to_user(const struct pci_dev *pdev, int bar,
			  const struct resource *rp, resource_size_t *start,
			  resource_size_t *end)
{
	struct pci_bus_region region;

	/*
	 * "User" addresses are shown in /sys/devices/pci.../.../resource
	 * and /proc/bus/pci/devices and used as mmap offsets for
	 * /proc/bus/pci/BB/DD.F files (see proc_bus_pci_mmap()).
	 *
	 * On sparc, these are PCI bus addresses, i.e., raw BAR values.
	 */
	pcibios_resource_to_bus(pdev->bus, &region, (struct resource *) rp);
	*start = region.start;
	*end = region.end;
}

void pcibios_set_master(struct pci_dev *dev)
{
	/* No special bus mastering setup handling */
}

#ifdef CONFIG_PCI_IOV
int pcibios_add_device(struct pci_dev *dev)
{
	struct pci_dev *pdev;

	/* Add sriov arch specific initialization here.
	 * Copy dev_archdata from PF to VF
	 */
	if (dev->is_virtfn) {
		struct dev_archdata *psd;

		pdev = dev->physfn;
		psd = &pdev->dev.archdata;
		pci_init_dev_archdata(&dev->dev.archdata, psd->iommu,
				      psd->stc, psd->host_controller, NULL,
				      psd->numa_node);
	}
	return 0;
}
#endif /* CONFIG_PCI_IOV */

static int __init pcibios_init(void)
{
	pci_dfl_cache_line_size = 64 >> 2;
	return 0;
}
subsys_initcall(pcibios_init);

#ifdef CONFIG_SYSFS

#define SLOT_NAME_SIZE  11  /* Max decimal digits + null in u32 */

static void pcie_bus_slot_names(struct pci_bus *pbus)
{
	struct pci_dev *pdev;
	struct pci_bus *bus;

	list_for_each_entry(pdev, &pbus->devices, bus_list) {
		char name[SLOT_NAME_SIZE];
		struct pci_slot *pci_slot;
		const u32 *slot_num;
		int len;

		slot_num = of_get_property(pdev->dev.of_node,
					   "physical-slot#", &len);

		if (slot_num == NULL || len != 4)
			continue;

		snprintf(name, sizeof(name), "%u", slot_num[0]);
		pci_slot = pci_create_slot(pbus, slot_num[0], name, NULL);

		if (IS_ERR(pci_slot))
			pr_err("PCI: pci_create_slot returned %ld.\n",
			       PTR_ERR(pci_slot));
	}

	list_for_each_entry(bus, &pbus->children, node)
		pcie_bus_slot_names(bus);
}

static void pci_bus_slot_names(struct device_node *node, struct pci_bus *bus)
{
	const struct pci_slot_names {
		u32	slot_mask;
		char	names[0];
	} *prop;
	const char *sp;
	int len, i;
	u32 mask;

	prop = of_get_property(node, "slot-names", &len);
	if (!prop)
		return;

	mask = prop->slot_mask;
	sp = prop->names;

	if (ofpci_verbose)
		pci_info(bus, "Making slots for [%pOF] mask[0x%02x]\n",
			 node, mask);

	i = 0;
	while (mask) {
		struct pci_slot *pci_slot;
		u32 this_bit = 1 << i;

		if (!(mask & this_bit)) {
			i++;
			continue;
		}

		if (ofpci_verbose)
			pci_info(bus, "Making slot [%s]\n", sp);

		pci_slot = pci_create_slot(bus, i, sp, NULL);
		if (IS_ERR(pci_slot))
			pci_err(bus, "pci_create_slot returned %ld\n",
				PTR_ERR(pci_slot));

		sp += strlen(sp) + 1;
		mask &= ~this_bit;
		i++;
	}
}

static int __init of_pci_slot_init(void)
{
	struct pci_bus *pbus = NULL;

	while ((pbus = pci_find_next_bus(pbus)) != NULL) {
		struct device_node *node;
		struct pci_dev *pdev;

		pdev = list_first_entry(&pbus->devices, struct pci_dev,
					bus_list);

		if (pdev && pci_is_pcie(pdev)) {
			pcie_bus_slot_names(pbus);
		} else {

			if (pbus->self) {

				/* PCI->PCI bridge */
				node = pbus->self->dev.of_node;

			} else {
				struct pci_pbm_info *pbm = pbus->sysdata;

				/* Host PCI controller */
				node = pbm->op->dev.of_node;
			}

			pci_bus_slot_names(node, pbus);
		}
	}

	return 0;
}
device_initcall(of_pci_slot_init);
#endif