quirks.c

IXP425 平台下嵌入式LINUX的PCI总线的驱动程序

/*
 * $Id: quirks.c,v 1.5 1998/05/02 19:24:14 mj Exp $
 *
 *  This file contains work-arounds for many known PCI hardware
 *  bugs.  Devices present only on certain architectures (host
 *  bridges et cetera) should be handled in arch-specific code.
 *
 *  Copyright (c) 1999 Martin Mares <[e-mail]>
 *
 *  The bridge optimization stuff has been removed. If you really
 *  have a silly BIOS which is unable to set your host bridge right,
 *  use the PowerTweak utility (see http://powertweak.sourceforge.net).
 */

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

#undef DEBUG

/* Deal with broken BIOS'es that neglect to enable passive release,
   which can cause problems in combination with the 82441FX/PPro MTRRs */
static void __init quirk_passive_release(struct pci_dev *dev)
{
	struct pci_dev *d = NULL;
	unsigned char dlc;

	/* We have to make sure a particular bit is set in the PIIX3
	   ISA bridge, so we have to go out and find it. */
	while ((d = pci_find_device(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371SB_0, d))) {
		pci_read_config_byte(d, 0x82, &dlc);
		if (!(dlc & 1<<1)) {
			printk(KERN_ERR "PCI: PIIX3: Enabling Passive Release on %s\n", d->slot_name);
			dlc |= 1<<1;
			pci_write_config_byte(d, 0x82, dlc);
		}
	}
}

/*  The VIA VP2/VP3/MVP3 seem to have some 'features'. There may be a workaround
    but VIA don't answer queries. If you happen to have good contacts at VIA
    ask them for me please -- Alan 
    
    This appears to be BIOS not version dependent. So presumably there is a 
    chipset level fix */
    

int isa_dma_bridge_buggy;		/* Exported */
    
static void __init quirk_isa_dma_hangs(struct pci_dev *dev)
{
	if (!isa_dma_bridge_buggy) {
		isa_dma_bridge_buggy=1;
		printk(KERN_INFO "Activating ISA DMA hang workarounds.\n");
	}
}

int pci_pci_problems;

/*
 *	Chipsets where PCI->PCI transfers vanish or hang
 */

static void __init quirk_nopcipci(struct pci_dev *dev)
{
	if((pci_pci_problems&PCIPCI_FAIL)==0)
	{
		printk(KERN_INFO "Disabling direct PCI/PCI transfers.\n");
		pci_pci_problems|=PCIPCI_FAIL;
	}
}

/*
 *	Triton requires workarounds to be used by the drivers
 */
 
static void __init quirk_triton(struct pci_dev *dev)
{
	if((pci_pci_problems&PCIPCI_TRITON)==0)
	{
		printk(KERN_INFO "Limiting direct PCI/PCI transfers.\n");
		pci_pci_problems|=PCIPCI_TRITON;
	}
}

/*
 *	VIA Apollo KT133 needs PCI latency patch
 *	Made according to a windows driver based patch by George E. Breese
 *	see PCI Latency Adjust on http://www.viahardware.com/download/viatweak.shtm
 *      Also see http://www.au-ja.org/review-kt133a-1-en.phtml for the info on which 
 *	Mr Breese based his work.
 *
 *	Updated based on further information from the site and also on
 *	information provided by VIA 
 */
static void __init quirk_vialatency(struct pci_dev *dev)
{
	struct pci_dev *p;
	u8 rev;
	u8 busarb;
	/* Ok we have a potential problem chipset here. Now see if we have
	   a buggy southbridge */
	   
	p=pci_find_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686, NULL);
	if(p!=NULL)
	{
		pci_read_config_byte(p, PCI_CLASS_REVISION, &rev);
		/* 0x40 - 0x4f == 686B, 0x10 - 0x2f == 686A; thanks Dan Hollis */
		/* Check for buggy part revisions */
		if (rev < 0x40 || rev > 0x42) 
			return;
	}
	else
	{
		p = pci_find_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231, NULL);
		if(p==NULL)	/* No problem parts */
			return;
		pci_read_config_byte(p, PCI_CLASS_REVISION, &rev);
		/* Check for buggy part revisions */
		if (rev < 0x10 || rev > 0x12) 
			return;
	}
	
	/*
	 *	Ok we have the problem. Now set the PCI master grant to 
	 *	occur every master grant. The apparent bug is that under high
	 *	PCI load (quite common in Linux of course) you can get data
	 *	loss when the CPU is held off the bus for 3 bus master requests
	 *	This happens to include the IDE controllers....
	 *
	 *	VIA only apply this fix when an SB Live! is present but under
	 *	both Linux and Windows this isnt enough, and we have seen
	 *	corruption without SB Live! but with things like 3 UDMA IDE
	 *	controllers. So we ignore that bit of the VIA recommendation..
	 */

	pci_read_config_byte(dev, 0x76, &busarb);
	/* Set bit 4 and bi 5 of byte 76 to 0x01 
	   "Master priority rotation on every PCI master grant */
	busarb &= ~(1<<5);
	busarb |= (1<<4);
	pci_write_config_byte(dev, 0x76, busarb);
	printk(KERN_INFO "Applying VIA southbridge workaround.\n");
}

/*
 *	VIA Apollo VP3 needs ETBF on BT848/878
 */
 
static void __init quirk_viaetbf(struct pci_dev *dev)
{
	if((pci_pci_problems&PCIPCI_VIAETBF)==0)
	{
		printk(KERN_INFO "Limiting direct PCI/PCI transfers.\n");
		pci_pci_problems|=PCIPCI_VIAETBF;
	}
}
static void __init quirk_vsfx(struct pci_dev *dev)
{
	if((pci_pci_problems&PCIPCI_VSFX)==0)
	{
		printk(KERN_INFO "Limiting direct PCI/PCI transfers.\n");
		pci_pci_problems|=PCIPCI_VSFX;
	}
}


/*
 *	Natoma has some interesting boundary conditions with Zoran stuff
 *	at least
 */
 
static void __init quirk_natoma(struct pci_dev *dev)
{
	if((pci_pci_problems&PCIPCI_NATOMA)==0)
	{
		printk(KERN_INFO "Limiting direct PCI/PCI transfers.\n");
		pci_pci_problems|=PCIPCI_NATOMA;
	}
}

/*
 *  S3 868 and 968 chips report region size equal to 32M, but they decode 64M.
 *  If it's needed, re-allocate the region.
 */

static void __init quirk_s3_64M(struct pci_dev *dev)
{
	struct resource *r = &dev->resource[0];

	if ((r->start & 0x3ffffff) || r->end != r->start + 0x3ffffff) {
		r->start = 0;
		r->end = 0x3ffffff;
	}
}

static void __init quirk_io_region(struct pci_dev *dev, unsigned region, unsigned size, int nr)
{
	region &= ~(size-1);
	if (region) {
		struct resource *res = dev->resource + nr;

		res->name = dev->name;
		res->start = region;
		res->end = region + size - 1;
		res->flags = IORESOURCE_IO;
		pci_claim_resource(dev, nr);
	}
}	

/*
 * Let's make the southbridge information explicit instead
 * of having to worry about people probing the ACPI areas,
 * for example.. (Yes, it happens, and if you read the wrong
 * ACPI register it will put the machine to sleep with no
 * way of waking it up again. Bummer).
 *
 * ALI M7101: Two IO regions pointed to by words at
 *	0xE0 (64 bytes of ACPI registers)
 *	0xE2 (32 bytes of SMB registers)
 */
static void __init quirk_ali7101_acpi(struct pci_dev *dev)
{
	u16 region;

	pci_read_config_word(dev, 0xE0, &region);
	quirk_io_region(dev, region, 64, PCI_BRIDGE_RESOURCES);
	pci_read_config_word(dev, 0xE2, &region);
	quirk_io_region(dev, region, 32, PCI_BRIDGE_RESOURCES+1);
}

/*
 * PIIX4 ACPI: Two IO regions pointed to by longwords at
 *	0x40 (64 bytes of ACPI registers)
 *	0x90 (32 bytes of SMB registers)
 */
static void __init quirk_piix4_acpi(struct pci_dev *dev)
{
	u32 region;

	pci_read_config_dword(dev, 0x40, &region);
	quirk_io_region(dev, region, 64, PCI_BRIDGE_RESOURCES);
	pci_read_config_dword(dev, 0x90, &region);
	quirk_io_region(dev, region, 32, PCI_BRIDGE_RESOURCES+1);
}

/*
 * VIA ACPI: One IO region pointed to by longword at
 *	0x48 or 0x20 (256 bytes of ACPI registers)
 */
static void __init quirk_vt82c586_acpi(struct pci_dev *dev)
{
	u8 rev;
	u32 region;

	pci_read_config_byte(dev, PCI_CLASS_REVISION, &rev);
	if (rev & 0x10) {
		pci_read_config_dword(dev, 0x48, &region);
		region &= PCI_BASE_ADDRESS_IO_MASK;
		quirk_io_region(dev, region, 256, PCI_BRIDGE_RESOURCES);
	}
}

/*
 * VIA VT82C686 ACPI: Three IO region pointed to by (long)words at
 *	0x48 (256 bytes of ACPI registers)
 *	0x70 (128 bytes of hardware monitoring register)
 *	0x90 (16 bytes of SMB registers)
 */
static void __init quirk_vt82c686_acpi(struct pci_dev *dev)
{
	u16 hm;
	u32 smb;