pci.c

底层驱动开发

	return 0;
}

subsys_initcall(pcibios_init);

void pcibios_fixup_bus(struct pci_bus *pbus)
{
	struct pci_pbm_info *pbm = pbus->sysdata;

	/* Generic PCI bus probing sets these to point at
	 * &io{port,mem}_resouce which is wrong for us.
	 */
	pbus->resource[0] = &pbm->io_space;
	pbus->resource[1] = &pbm->mem_space;
}

struct resource *pcibios_select_root(struct pci_dev *pdev, struct resource *r)
{
	struct pci_pbm_info *pbm = pdev->bus->sysdata;
	struct resource *root = NULL;

	if (r->flags & IORESOURCE_IO)
		root = &pbm->io_space;
	if (r->flags & IORESOURCE_MEM)
		root = &pbm->mem_space;

	return root;
}

void pcibios_update_irq(struct pci_dev *pdev, int irq)
{
}

void pcibios_align_resource(void *data, struct resource *res,
			    unsigned long size, unsigned long align)
{
}

int pcibios_enable_device(struct pci_dev *pdev, int mask)
{
	return 0;
}

void pcibios_resource_to_bus(struct pci_dev *pdev, struct pci_bus_region *region,
			     struct resource *res)
{
	struct pci_pbm_info *pbm = pdev->bus->sysdata;
	struct resource zero_res, *root;

	zero_res.start = 0;
	zero_res.end = 0;
	zero_res.flags = res->flags;

	if (res->flags & IORESOURCE_IO)
		root = &pbm->io_space;
	else
		root = &pbm->mem_space;

	pbm->parent->resource_adjust(pdev, &zero_res, root);

	region->start = res->start - zero_res.start;
	region->end = res->end - zero_res.start;
}

void pcibios_bus_to_resource(struct pci_dev *pdev, struct resource *res,
			     struct pci_bus_region *region)
{
	struct pci_pbm_info *pbm = pdev->bus->sysdata;
	struct resource *root;

	res->start = region->start;
	res->end = region->end;

	if (res->flags & IORESOURCE_IO)
		root = &pbm->io_space;
	else
		root = &pbm->mem_space;

	pbm->parent->resource_adjust(pdev, res, root);
}
EXPORT_SYMBOL(pcibios_bus_to_resource);

char * __init pcibios_setup(char *str)
{
	if (!strcmp(str, "onboardfirst")) {
		pci_device_reorder = 1;
		return NULL;
	}
	if (!strcmp(str, "noreorder")) {
		pci_device_reorder = 0;
		return NULL;
	}
	return str;
}

/* 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 pcidev_cookie *pcp = pdev->sysdata;
	struct pci_pbm_info *pbm;
	struct pci_controller_info *p;
	unsigned long space_size, user_offset, user_size;

	if (!pcp)
		return -ENXIO;
	pbm = pcp->pbm;
	if (!pbm)
		return -ENXIO;

	p = pbm->parent;
	if (p->pbms_same_domain) {
		unsigned long lowest, highest;

		lowest = ~0UL; highest = 0UL;
		if (mmap_state == pci_mmap_io) {
			if (p->pbm_A.io_space.flags) {
				lowest = p->pbm_A.io_space.start;
				highest = p->pbm_A.io_space.end + 1;
			}
			if (p->pbm_B.io_space.flags) {
				if (lowest > p->pbm_B.io_space.start)
					lowest = p->pbm_B.io_space.start;
				if (highest < p->pbm_B.io_space.end + 1)
					highest = p->pbm_B.io_space.end + 1;
			}
			space_size = highest - lowest;
		} else {
			if (p->pbm_A.mem_space.flags) {
				lowest = p->pbm_A.mem_space.start;
				highest = p->pbm_A.mem_space.end + 1;
			}
			if (p->pbm_B.mem_space.flags) {
				if (lowest > p->pbm_B.mem_space.start)
					lowest = p->pbm_B.mem_space.start;
				if (highest < p->pbm_B.mem_space.end + 1)
					highest = p->pbm_B.mem_space.end + 1;
			}
			space_size = highest - lowest;
		}
	} else {
		if (mmap_state == pci_mmap_io) {
			space_size = (pbm->io_space.end -
				      pbm->io_space.start) + 1;
		} else {
			space_size = (pbm->mem_space.end -
				      pbm->mem_space.start) + 1;
		}
	}

	/* 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 (p->pbms_same_domain) {
		unsigned long lowest = ~0UL;

		if (mmap_state == pci_mmap_io) {
			if (p->pbm_A.io_space.flags)
				lowest = p->pbm_A.io_space.start;
			if (p->pbm_B.io_space.flags &&
			    lowest > p->pbm_B.io_space.start)
				lowest = p->pbm_B.io_space.start;
		} else {
			if (p->pbm_A.mem_space.flags)
				lowest = p->pbm_A.mem_space.start;
			if (p->pbm_B.mem_space.flags &&
			    lowest > p->pbm_B.mem_space.start)
				lowest = p->pbm_B.mem_space.start;
		}
		vma->vm_pgoff = (lowest + user_offset) >> PAGE_SHIFT;
	} else {
		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 *dev, struct vm_area_struct *vma,
				  enum pci_mmap_state mmap_state)
{
	unsigned long user_offset = vma->vm_pgoff << PAGE_SHIFT;
	unsigned long user32 = user_offset & pci_memspace_mask;
	unsigned long largest_base, this_base, addr32;
	int i;

	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_HOST)
		return __pci_mmap_make_offset_bus(dev, vma, mmap_state);

	/* Figure out which base address this is for. */
	largest_base = 0UL;
	for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
		struct resource *rp = &dev->resource[i];

		/* 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;
		}

		this_base = rp->start;

		addr32 = (this_base & PAGE_MASK) & pci_memspace_mask;

		if (mmap_state == pci_mmap_io)
			addr32 &= 0xffffff;

		if (addr32 <= user32 && this_base > largest_base)
			largest_base = this_base;
	}

	if (largest_base == 0UL)
		return -EINVAL;

	/* Now construct the final physical address. */
	if (mmap_state == pci_mmap_io)
		vma->vm_pgoff = (((largest_base & ~0xffffffUL) | user32) >> PAGE_SHIFT);
	else
		vma->vm_pgoff = (((largest_base & ~(pci_memspace_mask)) | user32) >> PAGE_SHIFT);

	return 0;
}

/* Set vm_flags of VMA, as appropriate for this architecture, for a pci device
 * mapping.
 */
static void __pci_mmap_set_flags(struct pci_dev *dev, struct vm_area_struct *vma,
					    enum pci_mmap_state mmap_state)
{
	vma->vm_flags |= (VM_IO | VM_RESERVED);
}

/* 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, 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_flags(dev, vma, mmap_state);
	__pci_mmap_set_pgprot(dev, vma, mmap_state);

	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;

	vma->vm_flags |= VM_IO;
	return 0;
}

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

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

	if (pbm == NULL || pbm->parent == NULL) {
		ret = -ENXIO;
	} else {
		struct pci_controller_info *p = pbm->parent;

		ret = p->index;
		if (p->pbms_same_domain == 0)
			ret = ((ret << 1) +
			       ((pbm == &pbm->parent->pbm_B) ? 1 : 0));
	}

	return ret;
}
EXPORT_SYMBOL(pci_domain_nr);

int pcibios_prep_mwi(struct pci_dev *dev)
{
	/* We set correct PCI_CACHE_LINE_SIZE register values for every
	 * device probed on this platform.  So there is nothing to check
	 * and this always succeeds.
	 */
	return 0;
}

#endif /* !(CONFIG_PCI) */