linux/arch/powerpc/kernel/pci-common.c

/*
 * Contains common pci routines for ALL ppc platform
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#undef DEBUG

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mm.h>
#include <linux/list.h>
#include <linux/syscalls.h>
#include <linux/irq.h>
#include <linux/vmalloc.h>

#include <asm/processor.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/byteorder.h>
#include <asm/machdep.h>
#include <asm/ppc-pci.h>
#include <asm/firmware.h>

#ifdef DEBUG
#include <asm/udbg.h>
#define DBG(fmt...) printk(fmt)
#else
#define DBG(fmt...)
#endif

/*
 * Return the domain number for this bus.
 */
int pci_domain_nr(struct pci_bus *bus)
{
	if (firmware_has_feature(FW_FEATURE_ISERIES))
		return 0;
	else {
		struct pci_controller *hose = pci_bus_to_host(bus);

		return hose->global_number;
	}
}

EXPORT_SYMBOL(pci_domain_nr);

#ifdef CONFIG_PPC_OF
static ssize_t pci_show_devspec(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct pci_dev *pdev;
	struct device_node *np;

	pdev = to_pci_dev (dev);
	np = pci_device_to_OF_node(pdev);
	if (np == NULL || np->full_name == NULL)
		return 0;
	return sprintf(buf, "%s", np->full_name);
}
static DEVICE_ATTR(devspec, S_IRUGO, pci_show_devspec, NULL);
#endif /* CONFIG_PPC_OF */

/* Add sysfs properties */
void pcibios_add_platform_entries(struct pci_dev *pdev)
{
#ifdef CONFIG_PPC_OF
	device_create_file(&pdev->dev, &dev_attr_devspec);
#endif /* CONFIG_PPC_OF */
}

char __init *pcibios_setup(char *str)
{
	return str;
}

/*
 * Reads the interrupt pin to determine if interrupt is use by card.
 * If the interrupt is used, then gets the interrupt line from the
 * openfirmware and sets it in the pci_dev and pci_config line.
 */
int pci_read_irq_line(struct pci_dev *pci_dev)
{
	struct of_irq oirq;
	unsigned int virq;

	DBG("Try to map irq for %s...\n", pci_name(pci_dev));

#ifdef DEBUG
	memset(&oirq, 0xff, sizeof(oirq));
#endif
	/* Try to get a mapping from the device-tree */
	if (of_irq_map_pci(pci_dev, &oirq)) {
		u8 line, pin;

		/* If that fails, lets fallback to what is in the config
		 * space and map that through the default controller. We
		 * also set the type to level low since that's what PCI
		 * interrupts are. If your platform does differently, then
		 * either provide a proper interrupt tree or don't use this
		 * function.
		 */
		if (pci_read_config_byte(pci_dev, PCI_INTERRUPT_PIN, &pin))
			return -1;
		if (pin == 0)
			return -1;
		if (pci_read_config_byte(pci_dev, PCI_INTERRUPT_LINE, &line) ||
		    line == 0xff) {
			return -1;
		}
		DBG(" -> no map ! Using irq line %d from PCI config\n", line);

		virq = irq_create_mapping(NULL, line);
		if (virq != NO_IRQ)
			set_irq_type(virq, IRQ_TYPE_LEVEL_LOW);
	} else {
		DBG(" -> got one, spec %d cells (0x%08x 0x%08x...) on %s\n",
		    oirq.size, oirq.specifier[0], oirq.specifier[1],
		    oirq.controller->full_name);

		virq = irq_create_of_mapping(oirq.controller, oirq.specifier,
					     oirq.size);
	}
	if(virq == NO_IRQ) {
		DBG(" -> failed to map !\n");
		return -1;
	}

	DBG(" -> mapped to linux irq %d\n", virq);

	pci_dev->irq = virq;

	return 0;
}
EXPORT_SYMBOL(pci_read_irq_line);

/*
 * Platform support for /proc/bus/pci/X/Y mmap()s,
 * modelled on the sparc64 implementation by Dave Miller.
 *  -- paulus.
 */

/*
 * 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 struct resource *__pci_mmap_make_offset(struct pci_dev *dev,
					       resource_size_t *offset,
					       enum pci_mmap_state mmap_state)
{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	unsigned long io_offset = 0;
	int i, res_bit;

	if (hose == 0)
		return NULL;		/* should never happen */

	/* If memory, add on the PCI bridge address offset */
	if (mmap_state == pci_mmap_mem) {
#if 0 /* See comment in pci_resource_to_user() for why this is disabled */
		*offset += hose->pci_mem_offset;
#endif
		res_bit = IORESOURCE_MEM;
	} else {
		io_offset = (unsigned long)hose->io_base_virt - _IO_BASE;
		*offset += io_offset;
		res_bit = IORESOURCE_IO;
	}

	/*
	 * Check that the offset requested corresponds to one of the
	 * resources of the device.
	 */
	for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
		struct resource *rp = &dev->resource[i];
		int flags = rp->flags;

		/* treat ROM as memory (should be already) */
		if (i == PCI_ROM_RESOURCE)
			flags |= IORESOURCE_MEM;

		/* Active and same type? */
		if ((flags & res_bit) == 0)
			continue;

		/* In the range of this resource? */
		if (*offset < (rp->start & PAGE_MASK) || *offset > rp->end)
			continue;

		/* found it! construct the final physical address */
		if (mmap_state == pci_mmap_io)
			*offset += hose->io_base_phys - io_offset;
		return rp;
	}

	return NULL;
}

/*
 * Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
 * device mapping.
 */
static pgprot_t __pci_mmap_set_pgprot(struct pci_dev *dev, struct resource *rp,
				      pgprot_t protection,
				      enum pci_mmap_state mmap_state,
				      int write_combine)
{
	unsigned long prot = pgprot_val(protection);

	/* Write combine is always 0 on non-memory space mappings. On
	 * memory space, if the user didn't pass 1, we check for a
	 * "prefetchable" resource. This is a bit hackish, but we use
	 * this to workaround the inability of /sysfs to provide a write
	 * combine bit
	 */
	if (mmap_state != pci_mmap_mem)
		write_combine = 0;
	else if (write_combine == 0) {
		if (rp->flags & IORESOURCE_PREFETCH)
			write_combine = 1;
	}

	/* XXX would be nice to have a way to ask for write-through */
	prot |= _PAGE_NO_CACHE;
	if (write_combine)
		prot &= ~_PAGE_GUARDED;
	else
		prot |= _PAGE_GUARDED;

	return __pgprot(prot);
}

/*
 * This one is used by /dev/mem and fbdev who have no clue about the
 * PCI device, it tries to find the PCI device first and calls the
 * above routine
 */
pgprot_t pci_phys_mem_access_prot(struct file *file,
				  unsigned long pfn,
				  unsigned long size,
				  pgprot_t protection)
{
	struct pci_dev *pdev = NULL;
	struct resource *found = NULL;
	unsigned long prot = pgprot_val(protection);
	unsigned long offset = pfn << PAGE_SHIFT;
	int i;

	if (page_is_ram(pfn))
		return __pgprot(prot);

	prot |= _PAGE_NO_CACHE | _PAGE_GUARDED;

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

			/* Active and same type? */
			if ((flags & IORESOURCE_MEM) == 0)
				continue;
			/* In the range of this resource? */
			if (offset < (rp->start & PAGE_MASK) ||
			    offset > rp->end)
				continue;
			found = rp;
			break;
		}
		if (found)
			break;
	}
	if (found) {
		if (found->flags & IORESOURCE_PREFETCH)
			prot &= ~_PAGE_GUARDED;
		pci_dev_put(pdev);
	}

	DBG("non-PCI map for %lx, prot: %lx\n", offset, prot);

	return __pgprot(prot);
}


/*
 * 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)
{
	resource_size_t offset = vma->vm_pgoff << PAGE_SHIFT;
	struct resource *rp;
	int ret;

	rp = __pci_mmap_make_offset(dev, &offset, mmap_state);
	if (rp == NULL)
		return -EINVAL;

	vma->vm_pgoff = offset >> PAGE_SHIFT;
	vma->vm_page_prot = __pci_mmap_set_pgprot(dev, rp,
						  vma->vm_page_prot,
						  mmap_state, write_combine);

	ret = remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
			       vma->vm_end - vma->vm_start, vma->vm_page_prot);

	return ret;
}

void pci_resource_to_user(const struct pci_dev *dev, int bar,
			  const struct resource *rsrc,
			  resource_size_t *start, resource_size_t *end)
{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	resource_size_t offset = 0;

	if (hose == NULL)
		return;

	if (rsrc->flags & IORESOURCE_IO)
		offset = (unsigned long)hose->io_base_virt - _IO_BASE;

	/* We pass a fully fixed up address to userland for MMIO instead of
	 * a BAR value because X is lame and expects to be able to use that
	 * to pass to /dev/mem !
	 *
	 * That means that we'll have potentially 64 bits values where some
	 * userland apps only expect 32 (like X itself since it thinks only
	 * Sparc has 64 bits MMIO) but if we don't do that, we break it on
	 * 32 bits CHRPs :-(
	 *
	 * Hopefully, the sysfs insterface is immune to that gunk. Once X
	 * has been fixed (and the fix spread enough), we can re-enable the
	 * 2 lines below and pass down a BAR value to userland. In that case
	 * we'll also have to re-enable the matching code in
	 * __pci_mmap_make_offset().
	 *
	 * BenH.
	 */
#if 0
	else if (rsrc->flags & IORESOURCE_MEM)
		offset = hose->pci_mem_offset;
#endif

	*start = rsrc->start - offset;
	*end = rsrc->end - offset;
}