pci.c

讲述linux的初始化过程

/*
 *	linux/arch/alpha/kernel/pci.c
 *
 * Extruded from code written by
 *	Dave Rusling ([e-mail])
 *	David Mosberger ([e-mail])
 */

/* 2.3.x PCI/resources, 1999 Andrea Arcangeli <[e-mail]> */

/*
 * Nov 2000, Ivan Kokshaysky <[e-mail]>
 *	     PCI-PCI bridges cleanup
 */

#include <linux/string.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/bootmem.h>
#include <asm/machvec.h>

#include "proto.h"
#include "pci_impl.h"


/*
 * Some string constants used by the various core logics. 
 */

const char *const pci_io_names[] = {
  "PCI IO bus 0", "PCI IO bus 1", "PCI IO bus 2", "PCI IO bus 3",
  "PCI IO bus 4", "PCI IO bus 5", "PCI IO bus 6", "PCI IO bus 7"
};

const char *const pci_mem_names[] = {
  "PCI mem bus 0", "PCI mem bus 1", "PCI mem bus 2", "PCI mem bus 3",
  "PCI mem bus 4", "PCI mem bus 5", "PCI mem bus 6", "PCI mem bus 7"
};

const char pci_hae0_name[] = "HAE0";


/*
 * The PCI controler list.
 */

struct pci_controler *hose_head, **hose_tail = &hose_head;
struct pci_controler *pci_isa_hose;

/*
 * Quirks.
 */

static void __init
quirk_eisa_bridge(struct pci_dev *dev)
{
	dev->class = PCI_CLASS_BRIDGE_EISA << 8;
}

static void __init
quirk_isa_bridge(struct pci_dev *dev)
{
	dev->class = PCI_CLASS_BRIDGE_ISA << 8;
}

static void __init
quirk_ali_ide_ports(struct pci_dev *dev)
{
	if (dev->resource[0].end == 0xffff)
		dev->resource[0].end = dev->resource[0].start + 7;
	if (dev->resource[2].end == 0xffff)
		dev->resource[2].end = dev->resource[2].start + 7;
	if (dev->resource[3].end == 0xffff)
		dev->resource[3].end = dev->resource[3].start + 7;
}

/*
 * Notorious Cy82C693 chip. One of its numerous bugs: although
 * Cypress IDE controller doesn't support native mode, it has
 * programmable addresses of IDE command/control registers.
 * This violates PCI specifications, confuses IDE subsystem
 * and causes resource conflict between primary HD_CMD register
 * and floppy controller. Ugh.
 * Fix that.
 */
static void __init
quirk_cypress_ide_ports(struct pci_dev *dev)
{
	if (dev->class >> 8 != PCI_CLASS_STORAGE_IDE)
		return;
	dev->resource[0].flags = 0;
	dev->resource[1].flags = 0;
}

static void __init
quirk_vga_enable_rom(struct pci_dev *dev)
{
	/* If it's a VGA, enable its BIOS ROM at C0000.
	   But if its a Cirrus 543x/544x DISABLE it, since
	   enabling ROM disables the memory... */
	if ((dev->class >> 8) == PCI_CLASS_DISPLAY_VGA &&
	    (dev->vendor != PCI_VENDOR_ID_CIRRUS ||
	     (dev->device < 0x00a0) || (dev->device > 0x00ac)))
	{
		u32 reg;

		pci_read_config_dword(dev, dev->rom_base_reg, &reg);
		reg |= PCI_ROM_ADDRESS_ENABLE;
		pci_write_config_dword(dev, dev->rom_base_reg, reg);
		dev->resource[PCI_ROM_RESOURCE].flags |= PCI_ROM_ADDRESS_ENABLE;
	}
}

struct pci_fixup pcibios_fixups[] __initdata = {
	{ PCI_FIXUP_HEADER, PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82375,
	  quirk_eisa_bridge },
	{ PCI_FIXUP_HEADER, PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82378,
	  quirk_isa_bridge },
	{ PCI_FIXUP_HEADER, PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M5229,
	  quirk_ali_ide_ports },
	{ PCI_FIXUP_HEADER, PCI_VENDOR_ID_CONTAQ, PCI_DEVICE_ID_CONTAQ_82C693,
	  quirk_cypress_ide_ports },
	{ PCI_FIXUP_FINAL, PCI_ANY_ID, PCI_ANY_ID, quirk_vga_enable_rom },
	{ 0 }
};

#define MAX(val1, val2)		((val1) > (val2) ? (val1) : (val2))
#define ALIGN(val,align)	(((val) + ((align) - 1)) & ~((align) - 1))
#define KB			1024
#define MB			(1024*KB)
#define GB			(1024*MB)

void
pcibios_align_resource(void *data, struct resource *res, unsigned long size)
{
	struct pci_dev *dev = data;
	struct pci_controler *hose = dev->sysdata;
	unsigned long alignto;
	unsigned long start = res->start;

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

		/*
		 * Put everything into 0x00-0xff region modulo 0x400
		 */
		if (start & 0x300) {
			start = (start + 0x3ff) & ~0x3ff;
			res->start = start;
		}
	}
	else if	(res->flags & IORESOURCE_MEM) {
		/* Make sure we start at our min on all hoses */
		if (start - hose->mem_space->start < PCIBIOS_MIN_MEM)
			start = PCIBIOS_MIN_MEM + hose->io_space->start;

		/*
		 * The following holds at least for the Low Cost
		 * Alpha implementation of the PCI interface:
		 *
		 * In sparse memory address space, the first
		 * octant (16MB) of every 128MB segment is
		 * aliased to the very first 16 MB of the
		 * address space (i.e., it aliases the ISA
		 * memory address space).  Thus, we try to
		 * avoid allocating PCI devices in that range.
		 * Can be allocated in 2nd-7th octant only.
		 * Devices that need more than 112MB of
		 * address space must be accessed through
		 * dense memory space only!
		 */

		/* Align to multiple of size of minimum base.  */
		alignto = MAX(0x1000, size);
		start = ALIGN(start, alignto);
		if (size <= 7 * 16*MB) {
			if (((start / (16*MB)) & 0x7) == 0) {
				start &= ~(128*MB - 1);
				start += 16*MB;
				start  = ALIGN(start, alignto);
			}
			if (start/(128*MB) != (start + size)/(128*MB)) {
				start &= ~(128*MB - 1);
				start += (128 + 16)*MB;
				start  = ALIGN(start, alignto);
			}
		}
	}

	res->start = start;
}
#undef MAX
#undef ALIGN
#undef KB
#undef MB
#undef GB

void __init
pcibios_init(void)
{
	if (!alpha_mv.init_pci)
		return;
	alpha_mv.init_pci();
}

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

void __init
pcibios_fixup_resource(struct resource *res, struct resource *root)
{
	res->start += root->start;
	res->end += root->start;
}

void __init
pcibios_fixup_device_resources(struct pci_dev *dev, struct pci_bus *bus)
{
	/* Update device resources.  */
	struct pci_controler *hose = (struct pci_controler *)bus->sysdata;
	int i;

	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
		if (!dev->resource[i].start)
			continue;
		if (dev->resource[i].flags & IORESOURCE_IO)
			pcibios_fixup_resource(&dev->resource[i],
					       hose->io_space);
		else if (dev->resource[i].flags & IORESOURCE_MEM)
			pcibios_fixup_resource(&dev->resource[i],
					       hose->mem_space);
	}
}

void __init
pcibios_fixup_bus(struct pci_bus *bus)
{
	/* Propogate hose info into the subordinate devices.  */

	struct pci_controler *hose = bus->sysdata;
	struct list_head *ln;
	struct pci_dev *dev = bus->self;

	if (!dev) {
		/* Root bus */
		bus->resource[0] = hose->io_space;
		bus->resource[1] = hose->mem_space;
	} else {
		/* This is a bridge. Do not care how it's initialized,
		   just link its resources to the bus ones */
		int i;

		for(i=0; i<3; i++) {
			bus->resource[i] =
				&dev->resource[PCI_BRIDGE_RESOURCES+i];
			bus->resource[i]->name = bus->name;
		}
		bus->resource[0]->flags |= pci_bridge_check_io(dev);
		bus->resource[1]->flags |= IORESOURCE_MEM;
		/* For now, propogate hose limits to the bus;
		   we'll adjust them later. */
		bus->resource[0]->end = hose->io_space->end;
		bus->resource[1]->end = hose->mem_space->end;
		/* Turn off downstream PF memory address range by default */
		bus->resource[2]->start = 1024*1024;
		bus->resource[2]->end = bus->resource[2]->start - 1;
	}

	for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) {
		struct pci_dev *dev = pci_dev_b(ln);
		if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
			pcibios_fixup_device_resources(dev, bus);
	}
}

void
pcibios_update_resource(struct pci_dev *dev, struct resource *root,
			struct resource *res, int resource)
{
	struct pci_controler *hose = dev->sysdata;
	int where;
	u32 reg;

	if (resource < PCI_ROM_RESOURCE) 
		where = PCI_BASE_ADDRESS_0 + (resource * 4);
	else if (resource == PCI_ROM_RESOURCE)
		where = dev->rom_base_reg;
	else {
		return; /* Don't update non-standard resources here. */
	}

	/* Point root at the hose root. */
	if (res->flags & IORESOURCE_IO)
		root = hose->io_space;
	if (res->flags & IORESOURCE_MEM)
		root = hose->mem_space;

	reg = (res->start - root->start) | (res->flags & 0xf);
	pci_write_config_dword(dev, where, reg);
	if ((res->flags & (PCI_BASE_ADDRESS_SPACE
			   | PCI_BASE_ADDRESS_MEM_TYPE_MASK))
	    == (PCI_BASE_ADDRESS_SPACE_MEMORY
		| PCI_BASE_ADDRESS_MEM_TYPE_64)) {
		pci_write_config_dword(dev, where+4, 0);
		printk(KERN_WARNING "PCI: dev %s type 64-bit\n", dev->name);
	}

	/* ??? FIXME -- record old value for shutdown.  */
}

void __init
pcibios_update_irq(struct pci_dev *dev, int irq)
{
	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);

	/* ??? FIXME -- record old value for shutdown.  */
}

/* Most Alphas have straight-forward swizzling needs.  */

u8 __init
common_swizzle(struct pci_dev *dev, u8 *pinp)
{
	struct pci_controler *hose = dev->sysdata;

	if (dev->bus->number != hose->first_busno) {
		u8 pin = *pinp;
		do {
			pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn));
			/* Move up the chain of bridges. */
			dev = dev->bus->self;
		} while (dev->bus->self);
		*pinp = pin;

		/* The slot is the slot of the last bridge. */
	}

	return PCI_SLOT(dev->devfn);
}

void __init
pcibios_fixup_pbus_ranges(struct pci_bus * bus,
			  struct pbus_set_ranges_data * ranges)
{
	struct pci_controler *hose = (struct pci_controler *)bus->sysdata;

	ranges->io_start -= hose->io_space->start;
	ranges->io_end -= hose->io_space->start;
	ranges->mem_start -= hose->mem_space->start;
	ranges->mem_end -= hose->mem_space->start;
}

int
pcibios_enable_device(struct pci_dev *dev)
{
	/* Nothing to do, since we enable all devices at startup.  */
	return 0;
}

/*
 *  If we set up a device for bus mastering, we need to check the latency
 *  timer as certain firmware forgets to set it properly, as seen
 *  on SX164 and LX164 with SRM.
 */
void
pcibios_set_master(struct pci_dev *dev)
{
	u8 lat;
	pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
	if (lat >= 16) return;
	printk("PCI: Setting latency timer of device %s to 64\n",
							dev->slot_name);
	pci_write_config_byte(dev, PCI_LATENCY_TIMER, 64);
}

void __init
common_init_pci(void)
{
	struct pci_controler *hose;
	struct pci_bus *bus;
	int next_busno;

	/* Scan all of the recorded PCI controlers.  */
	for (next_busno = 0, hose = hose_head; hose; hose = hose->next) {
		hose->first_busno = next_busno;
		hose->last_busno = 0xff;
		bus = pci_scan_bus(next_busno, alpha_mv.pci_ops, hose);
		hose->bus = bus;
		next_busno = hose->last_busno = bus->subordinate;
		next_busno += 1;
	}

	pci_assign_unassigned_resources();
	pci_fixup_irqs(alpha_mv.pci_swizzle, alpha_mv.pci_map_irq);
}


struct pci_controler * __init
alloc_pci_controler(void)
{
	struct pci_controler *hose;

	hose = alloc_bootmem(sizeof(*hose));

	*hose_tail = hose;
	hose_tail = &hose->next;

	return hose;
}

struct resource * __init
alloc_resource(void)
{
	struct resource *res;

	res = alloc_bootmem(sizeof(*res));

	return res;
}


/* Provide information on locations of various I/O regions in physical
   memory.  Do this on a per-card basis so that we choose the right hose.  */

asmlinkage long
sys_pciconfig_iobase(long which, unsigned long bus, unsigned long dfn)
{
	struct pci_controler *hose;
	struct pci_dev *dev;

	/* from hose or from bus.devfn */
	if (which & IOBASE_FROM_HOSE) {
		for(hose = hose_head; hose; hose = hose->next) 
			if (hose->index == bus) break;
		if (!hose) return -ENODEV;
	} else {
	/* Special hook for ISA access.  */
	if (bus == 0 && dfn == 0) {
		hose = pci_isa_hose;
	} else {
		dev = pci_find_slot(bus, dfn);
		if (!dev)
			return -ENODEV;
		hose = dev->sysdata;
	}
	}

	switch (which & ~IOBASE_FROM_HOSE) {
	case IOBASE_HOSE:
		return hose->index;
	case IOBASE_SPARSE_MEM:
		return hose->sparse_mem_base;
	case IOBASE_DENSE_MEM:
		return hose->dense_mem_base;
	case IOBASE_SPARSE_IO:
		return hose->sparse_io_base;
	case IOBASE_DENSE_IO:
		return hose->dense_io_base;
	case IOBASE_ROOT_BUS:
		return hose->bus->number;
	}

	return -EOPNOTSUPP;
}