pci.c

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/*
 * Port for PPC64 David Engebretsen, IBM Corp.
 * Contains common pci routines for ppc64 platform, pSeries and iSeries brands.
 * 
 * Copyright (C) 2003 Anton Blanchard <[e-mail]>, IBM
 *   Rework, based on alpha PCI code.
 *
 *      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/config.h>
#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 <asm/processor.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/machdep.h>
#include <asm/udbg.h>

#include "pci.h"

#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif

unsigned long pci_probe_only = 1;
unsigned long pci_assign_all_buses = 0;

/*
 * legal IO pages under MAX_ISA_PORT.  This is to ensure we don't touch
 * devices we don't have access to.
 */
unsigned long io_page_mask;

EXPORT_SYMBOL(io_page_mask);


unsigned int pcibios_assign_all_busses(void)
{
	return pci_assign_all_buses;
}

/* pci_io_base -- the base address from which io bars are offsets.
 * This is the lowest I/O base address (so bar values are always positive),
 * and it *must* be the start of ISA space if an ISA bus exists because
 * ISA drivers use hard coded offsets.  If no ISA bus exists a dummy
 * page is mapped and isa_io_limit prevents access to it.
 */
unsigned long isa_io_base;	/* NULL if no ISA bus */
unsigned long pci_io_base;

void iSeries_pcibios_init(void);

LIST_HEAD(hose_list);

struct pci_dma_ops pci_dma_ops;
EXPORT_SYMBOL(pci_dma_ops);

int global_phb_number;		/* Global phb counter */

/* Cached ISA bridge dev. */
struct pci_dev *ppc64_isabridge_dev = NULL;

static void fixup_broken_pcnet32(struct pci_dev* dev)
{
	if ((dev->class>>8 == PCI_CLASS_NETWORK_ETHERNET)) {
		dev->vendor = PCI_VENDOR_ID_AMD;
		pci_write_config_word(dev, PCI_VENDOR_ID, PCI_VENDOR_ID_AMD);
		pci_name_device(dev);
	}
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_TRIDENT, PCI_ANY_ID, fixup_broken_pcnet32);

void  pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
			      struct resource *res)
{
	unsigned long offset = 0;
	struct pci_controller *hose = pci_bus_to_host(dev->bus);

	if (!hose)
		return;

	if (res->flags & IORESOURCE_IO)
	        offset = (unsigned long)hose->io_base_virt - pci_io_base;

	if (res->flags & IORESOURCE_MEM)
		offset = hose->pci_mem_offset;

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

#ifdef CONFIG_HOTPLUG
EXPORT_SYMBOL(pcibios_resource_to_bus);
#endif

/*
 * We need to avoid collisions with `mirrored' VGA ports
 * and other strange ISA hardware, so we always want the
 * addresses to be allocated in the 0x000-0x0ff region
 * modulo 0x400.
 *
 * Why? Because some silly external IO cards only decode
 * the low 10 bits of the IO address. The 0x00-0xff region
 * is reserved for motherboard devices that decode all 16
 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
 * but we want to try to avoid allocating at 0x2900-0x2bff
 * which might have be mirrored at 0x0100-0x03ff..
 */
void pcibios_align_resource(void *data, struct resource *res,
			    unsigned long size, unsigned long align)
{
	struct pci_dev *dev = data;
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	unsigned long start = res->start;
	unsigned long alignto;

	if (res->flags & IORESOURCE_IO) {
	        unsigned long offset = (unsigned long)hose->io_base_virt -
					pci_io_base;
		/* Make sure we start at our min on all hoses */
		if (start - offset < PCIBIOS_MIN_IO)
			start = PCIBIOS_MIN_IO + offset;

		/*
		 * Put everything into 0x00-0xff region modulo 0x400
		 */
		if (start & 0x300)
			start = (start + 0x3ff) & ~0x3ff;

	} else if (res->flags & IORESOURCE_MEM) {
		/* Make sure we start at our min on all hoses */
		if (start - hose->pci_mem_offset < PCIBIOS_MIN_MEM)
			start = PCIBIOS_MIN_MEM + hose->pci_mem_offset;

		/* Align to multiple of size of minimum base.  */
		alignto = max(0x1000UL, align);
		start = ALIGN(start, alignto);
	}

	res->start = start;
}

static DEFINE_SPINLOCK(hose_spinlock);

/*
 * pci_controller(phb) initialized common variables.
 */
void __devinit pci_setup_pci_controller(struct pci_controller *hose)
{
	memset(hose, 0, sizeof(struct pci_controller));

	spin_lock(&hose_spinlock);
	hose->global_number = global_phb_number++;
	list_add_tail(&hose->list_node, &hose_list);
	spin_unlock(&hose_spinlock);
}

static void __init pcibios_claim_one_bus(struct pci_bus *b)
{
	struct pci_dev *dev;
	struct pci_bus *child_bus;

	list_for_each_entry(dev, &b->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;
			pci_claim_resource(dev, i);
		}
	}

	list_for_each_entry(child_bus, &b->children, node)
		pcibios_claim_one_bus(child_bus);
}

#ifndef CONFIG_PPC_ISERIES
static void __init pcibios_claim_of_setup(void)
{
	struct pci_bus *b;

	list_for_each_entry(b, &pci_root_buses, node)
		pcibios_claim_one_bus(b);
}
#endif

static int __init pcibios_init(void)
{
	struct pci_controller *hose, *tmp;
	struct pci_bus *bus;

#ifdef CONFIG_PPC_ISERIES
	iSeries_pcibios_init(); 
#endif

	printk("PCI: Probing PCI hardware\n");

	/* Scan all of the recorded PCI controllers.  */
	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
		hose->last_busno = 0xff;
		bus = pci_scan_bus(hose->first_busno, hose->ops,
				   hose->arch_data);
		hose->bus = bus;
		hose->last_busno = bus->subordinate;
	}

#ifndef CONFIG_PPC_ISERIES
	if (pci_probe_only)
		pcibios_claim_of_setup();
	else
		/* FIXME: `else' will be removed when
		   pci_assign_unassigned_resources() is able to work
		   correctly with [partially] allocated PCI tree. */
		pci_assign_unassigned_resources();
#endif /* !CONFIG_PPC_ISERIES */

	/* Call machine dependent final fixup */
	if (ppc_md.pcibios_fixup)
		ppc_md.pcibios_fixup();

	/* Cache the location of the ISA bridge (if we have one) */
	ppc64_isabridge_dev = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, NULL);
	if (ppc64_isabridge_dev != NULL)
		printk("ISA bridge at %s\n", pci_name(ppc64_isabridge_dev));

	printk("PCI: Probing PCI hardware done\n");

	return 0;
}

subsys_initcall(pcibios_init);

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

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) {
		printk(KERN_DEBUG "PCI: Enabling device: (%s), cmd %x\n",
		       pci_name(dev), cmd);
                /* Enable the appropriate bits in the PCI command register.  */
		pci_write_config_word(dev, PCI_COMMAND, cmd);
	}
	return 0;
}

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

	return hose->global_number;
#endif
}

EXPORT_SYMBOL(pci_domain_nr);

/* Set the name of the bus as it appears in /proc/bus/pci */
int pci_name_bus(char *name, struct pci_bus *bus)
{
#ifndef CONFIG_PPC_ISERIES
	struct pci_controller *hose = pci_bus_to_host(bus);

	if (hose->buid)
		sprintf(name, "%04x:%02x", pci_domain_nr(bus), bus->number);
	else
#endif
		sprintf(name, "%02x", bus->number);

	return 0;
}

/*
 * 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 __inline__ int __pci_mmap_make_offset(struct pci_dev *dev,
					     struct vm_area_struct *vma,
					     enum pci_mmap_state mmap_state)
{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
	unsigned long io_offset = 0;
	int i, res_bit;

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

	/* If memory, add on the PCI bridge address offset */
	if (mmap_state == pci_mmap_mem) {
		offset += hose->pci_mem_offset;
		res_bit = IORESOURCE_MEM;
	} else {
		io_offset = (unsigned long)hose->io_base_virt;
		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;

		vma->vm_pgoff = offset >> PAGE_SHIFT;
		return 0;
	}

	return -EINVAL;
}

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

/*
 * Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
 * device mapping.
 */
static __inline__ void __pci_mmap_set_pgprot(struct pci_dev *dev,
					     struct vm_area_struct *vma,
					     enum pci_mmap_state mmap_state,
					     int write_combine)
{
	long prot = pgprot_val(vma->vm_page_prot);

	/* XXX would be nice to have a way to ask for write-through */
	prot |= _PAGE_NO_CACHE;
	if (!write_combine)
		prot |= _PAGE_GUARDED;
	vma->vm_page_prot = __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)
{
	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, write_combine);