pci-auto.c

LINUX 2.6.17.4的源码

/*
 * PCI autoconfiguration library
 *
 * Author: Matt Porter <[e-mail]>
 *
 * Copyright 2000, 2001 MontaVista Software Inc.
 * Copyright 2001 Bradley D. LaRonde <[e-mail]>
 * Copyright 2003 Paul Mundt <[e-mail]>
 *
 * 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.
 */

/*
 * Modified for MIPS by Jun Sun, [e-mail]
 *
 * . Simplify the interface between pci_auto and the rest: a single function.
 * . Assign resources from low address to upper address.
 * . change most int to u32.
 *
 * Further modified to include it as mips generic code, [e-mail].
 *
 * 2001-10-26  Bradley D. LaRonde <[e-mail]>
 * - Add a top_bus argument to the "early config" functions so that
 *   they can set a fake parent bus pointer to convince the underlying
 *   pci ops to use type 1 configuration for sub busses.
 * - Set bridge base and limit registers correctly.
 * - Align io and memory base properly before and after bridge setup.
 * - Don't fall through to pci_setup_bars for bridge.
 * - Reformat the debug output to look more like lspci's output.
 *
 * Cloned for SuperH by M. R. Brown, [e-mail]
 *
 * 2003-08-05  Paul Mundt <[e-mail]>
 * - Don't update the BAR values on systems that already have valid addresses
 *   and don't want these updated for whatever reason, by way of a new config
 *   option check. However, we still read in the old BAR values so that they
 *   can still be reported through the debug output.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/pci.h>

#undef	DEBUG
#ifdef 	DEBUG
#define	DBG(x...)	printk(x)
#else
#define	DBG(x...)	
#endif

/*
 * These functions are used early on before PCI scanning is done
 * and all of the pci_dev and pci_bus structures have been created.
 */
static struct pci_dev *fake_pci_dev(struct pci_channel *hose,
	int top_bus, int busnr, int devfn)
{
	static struct pci_dev dev;
	static struct pci_bus bus;

	dev.bus = &bus;
	dev.sysdata = hose;
	dev.devfn = devfn;
	bus.number = busnr;
	bus.ops = hose->pci_ops;

	if(busnr != top_bus)
		/* Fake a parent bus structure. */
		bus.parent = &bus;
	else
		bus.parent = NULL;

	return &dev;
}

#define EARLY_PCI_OP(rw, size, type)					\
int early_##rw##_config_##size(struct pci_channel *hose,		\
	int top_bus, int bus, int devfn, int offset, type value)	\
{									\
	return pci_##rw##_config_##size(				\
		fake_pci_dev(hose, top_bus, bus, devfn),		\
		offset, value);						\
}

EARLY_PCI_OP(read, byte, u8 *)
EARLY_PCI_OP(read, word, u16 *)
EARLY_PCI_OP(read, dword, u32 *)
EARLY_PCI_OP(write, byte, u8)
EARLY_PCI_OP(write, word, u16)
EARLY_PCI_OP(write, dword, u32)

static struct resource *io_resource_inuse;
static struct resource *mem_resource_inuse;

static u32 pciauto_lower_iospc;
static u32 pciauto_upper_iospc;

static u32 pciauto_lower_memspc;
static u32 pciauto_upper_memspc;

static void __init 
pciauto_setup_bars(struct pci_channel *hose,
		   int top_bus,
		   int current_bus,
		   int pci_devfn,
		   int bar_limit)
{
	u32 bar_response, bar_size, bar_value;
	u32 bar, addr_mask, bar_nr = 0;
	u32 * upper_limit;
	u32 * lower_limit;
	int found_mem64 = 0;

	for (bar = PCI_BASE_ADDRESS_0; bar <= bar_limit; bar+=4) {
#if !defined(CONFIG_SH_HS7751RVOIP) && !defined(CONFIG_SH_RTS7751R2D)
		u32 bar_addr;

		/* Read the old BAR value */
		early_read_config_dword(hose, top_bus,
					current_bus,
					pci_devfn,
					bar,
					&bar_addr);
#endif

		/* Tickle the BAR and get the response */
		early_write_config_dword(hose, top_bus,
					 current_bus,
					 pci_devfn,
					 bar,
					 0xffffffff);

		early_read_config_dword(hose, top_bus,
					current_bus,
					pci_devfn,
					bar,
					&bar_response);

#if !defined(CONFIG_SH_HS7751RVOIP) && !defined(CONFIG_SH_RTS7751R2D)
		/* 
		 * Write the old BAR value back out, only update the BAR
		 * if we implicitly want resources to be updated, which
		 * is done by the generic code further down. -- PFM.
		 */
		early_write_config_dword(hose, top_bus,
					 current_bus,
					 pci_devfn,
					 bar,
					 bar_addr);
#endif

		/* If BAR is not implemented go to the next BAR */
		if (!bar_response)
			continue;

		/*
		 * Workaround for a BAR that doesn't use its upper word,
		 * like the ALi 1535D+ PCI DC-97 Controller Modem (M5457).
		 * bdl <[e-mail]>
		 */
		if (!(bar_response & 0xffff0000))
			bar_response |= 0xffff0000;

retry:
		/* Check the BAR type and set our address mask */
		if (bar_response & PCI_BASE_ADDRESS_SPACE) {
			addr_mask = PCI_BASE_ADDRESS_IO_MASK;
			upper_limit = &pciauto_upper_iospc;
			lower_limit = &pciauto_lower_iospc;
			DBG("        I/O");
		} else {
			if ((bar_response & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
			    PCI_BASE_ADDRESS_MEM_TYPE_64)
				found_mem64 = 1;

			addr_mask = PCI_BASE_ADDRESS_MEM_MASK;		
			upper_limit = &pciauto_upper_memspc;
			lower_limit = &pciauto_lower_memspc;
			DBG("        Mem");
		}


		/* Calculate requested size */
		bar_size = ~(bar_response & addr_mask) + 1;

		/* Allocate a base address */
		bar_value = ((*lower_limit - 1) & ~(bar_size - 1)) + bar_size;

		if ((bar_value + bar_size) > *upper_limit) {
			if (bar_response & PCI_BASE_ADDRESS_SPACE) {
				if (io_resource_inuse->child) {
					io_resource_inuse = 
						io_resource_inuse->child;
					pciauto_lower_iospc = 
						io_resource_inuse->start;
					pciauto_upper_iospc = 
						io_resource_inuse->end + 1;
					goto retry;
				}

			} else {
				if (mem_resource_inuse->child) {
					mem_resource_inuse = 
						mem_resource_inuse->child;
					pciauto_lower_memspc = 
						mem_resource_inuse->start;
					pciauto_upper_memspc = 
						mem_resource_inuse->end + 1;
					goto retry;
				}
			}
			DBG(" unavailable -- skipping, value %x size %x\n",
					bar_value, bar_size);
			continue;
		}

#ifdef CONFIG_PCI_AUTO_UPDATE_RESOURCES
		/* Write it out and update our limit */
		early_write_config_dword(hose, top_bus, current_bus, pci_devfn,
					 bar, bar_value);
#endif

		*lower_limit = bar_value + bar_size;

		/*
		 * If we are a 64-bit decoder then increment to the
		 * upper 32 bits of the bar and force it to locate
		 * in the lower 4GB of memory.
		 */ 
		if (found_mem64) {
			bar += 4;
			early_write_config_dword(hose, top_bus,
						 current_bus,
						 pci_devfn,
						 bar,
						 0x00000000);
		}

		DBG(" at 0x%.8x [size=0x%x]\n", bar_value, bar_size);

		bar_nr++;
	}

}

static void __init
pciauto_prescan_setup_bridge(struct pci_channel *hose,
			     int top_bus,
			     int current_bus,
			     int pci_devfn,
			     int sub_bus)
{
	/* Configure bus number registers */
	early_write_config_byte(hose, top_bus, current_bus, pci_devfn,
	                        PCI_PRIMARY_BUS, current_bus);
	early_write_config_byte(hose, top_bus, current_bus, pci_devfn,
				PCI_SECONDARY_BUS, sub_bus + 1);
	early_write_config_byte(hose, top_bus, current_bus, pci_devfn,
				PCI_SUBORDINATE_BUS, 0xff);

	/* Align memory and I/O to 1MB and 4KB boundaries. */
	pciauto_lower_memspc = (pciauto_lower_memspc + (0x100000 - 1))
		& ~(0x100000 - 1);
	pciauto_lower_iospc = (pciauto_lower_iospc + (0x1000 - 1))
		& ~(0x1000 - 1);

	/* Set base (lower limit) of address range behind bridge. */
	early_write_config_word(hose, top_bus, current_bus, pci_devfn,
		PCI_MEMORY_BASE, pciauto_lower_memspc >> 16);
	early_write_config_byte(hose, top_bus, current_bus, pci_devfn,
		PCI_IO_BASE, (pciauto_lower_iospc & 0x0000f000) >> 8);
	early_write_config_word(hose, top_bus, current_bus, pci_devfn,
		PCI_IO_BASE_UPPER16, pciauto_lower_iospc >> 16);