As with any other such change, the goal is to prevent inadvertent writes to these structures (assuming DEBUG_RODATA is enabled), and to separate data (possibly frequently) written to from such never getting modified. Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
		
			
				
	
	
		
			315 lines
		
	
	
	
		
			6.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			315 lines
		
	
	
	
		
			6.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * direct.c - Low-level direct PCI config space access
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 */
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#include <linux/pci.h>
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#include <linux/init.h>
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#include <linux/dmi.h>
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#include <asm/pci_x86.h>
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/*
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 * Functions for accessing PCI base (first 256 bytes) and extended
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 * (4096 bytes per PCI function) configuration space with type 1
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 * accesses.
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 */
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#define PCI_CONF1_ADDRESS(bus, devfn, reg) \
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	(0x80000000 | ((reg & 0xF00) << 16) | (bus << 16) \
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	| (devfn << 8) | (reg & 0xFC))
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static int pci_conf1_read(unsigned int seg, unsigned int bus,
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			  unsigned int devfn, int reg, int len, u32 *value)
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{
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	unsigned long flags;
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	if (seg || (bus > 255) || (devfn > 255) || (reg > 4095)) {
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		*value = -1;
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		return -EINVAL;
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	}
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	raw_spin_lock_irqsave(&pci_config_lock, flags);
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	outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8);
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	switch (len) {
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	case 1:
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		*value = inb(0xCFC + (reg & 3));
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		break;
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	case 2:
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		*value = inw(0xCFC + (reg & 2));
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		break;
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	case 4:
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		*value = inl(0xCFC);
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		break;
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	}
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	raw_spin_unlock_irqrestore(&pci_config_lock, flags);
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	return 0;
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}
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static int pci_conf1_write(unsigned int seg, unsigned int bus,
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			   unsigned int devfn, int reg, int len, u32 value)
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{
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	unsigned long flags;
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	if (seg || (bus > 255) || (devfn > 255) || (reg > 4095))
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		return -EINVAL;
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	raw_spin_lock_irqsave(&pci_config_lock, flags);
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	outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8);
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	switch (len) {
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	case 1:
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		outb((u8)value, 0xCFC + (reg & 3));
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		break;
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	case 2:
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		outw((u16)value, 0xCFC + (reg & 2));
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		break;
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	case 4:
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		outl((u32)value, 0xCFC);
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		break;
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	}
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	raw_spin_unlock_irqrestore(&pci_config_lock, flags);
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	return 0;
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}
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#undef PCI_CONF1_ADDRESS
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const struct pci_raw_ops pci_direct_conf1 = {
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	.read =		pci_conf1_read,
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	.write =	pci_conf1_write,
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};
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/*
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 * Functions for accessing PCI configuration space with type 2 accesses
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 */
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#define PCI_CONF2_ADDRESS(dev, reg)	(u16)(0xC000 | (dev << 8) | reg)
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static int pci_conf2_read(unsigned int seg, unsigned int bus,
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			  unsigned int devfn, int reg, int len, u32 *value)
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{
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	unsigned long flags;
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	int dev, fn;
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	WARN_ON(seg);
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	if ((bus > 255) || (devfn > 255) || (reg > 255)) {
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		*value = -1;
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		return -EINVAL;
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	}
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	dev = PCI_SLOT(devfn);
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	fn = PCI_FUNC(devfn);
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	if (dev & 0x10) 
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		return PCIBIOS_DEVICE_NOT_FOUND;
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	raw_spin_lock_irqsave(&pci_config_lock, flags);
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	outb((u8)(0xF0 | (fn << 1)), 0xCF8);
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	outb((u8)bus, 0xCFA);
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	switch (len) {
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	case 1:
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		*value = inb(PCI_CONF2_ADDRESS(dev, reg));
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		break;
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	case 2:
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		*value = inw(PCI_CONF2_ADDRESS(dev, reg));
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		break;
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	case 4:
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		*value = inl(PCI_CONF2_ADDRESS(dev, reg));
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		break;
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	}
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	outb(0, 0xCF8);
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	raw_spin_unlock_irqrestore(&pci_config_lock, flags);
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	return 0;
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}
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static int pci_conf2_write(unsigned int seg, unsigned int bus,
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			   unsigned int devfn, int reg, int len, u32 value)
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{
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	unsigned long flags;
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	int dev, fn;
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	WARN_ON(seg);
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	if ((bus > 255) || (devfn > 255) || (reg > 255)) 
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		return -EINVAL;
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	dev = PCI_SLOT(devfn);
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	fn = PCI_FUNC(devfn);
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	if (dev & 0x10) 
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		return PCIBIOS_DEVICE_NOT_FOUND;
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	raw_spin_lock_irqsave(&pci_config_lock, flags);
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	outb((u8)(0xF0 | (fn << 1)), 0xCF8);
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	outb((u8)bus, 0xCFA);
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	switch (len) {
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	case 1:
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		outb((u8)value, PCI_CONF2_ADDRESS(dev, reg));
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		break;
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	case 2:
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		outw((u16)value, PCI_CONF2_ADDRESS(dev, reg));
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		break;
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	case 4:
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		outl((u32)value, PCI_CONF2_ADDRESS(dev, reg));
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		break;
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	}
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	outb(0, 0xCF8);    
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	raw_spin_unlock_irqrestore(&pci_config_lock, flags);
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	return 0;
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}
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#undef PCI_CONF2_ADDRESS
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static const struct pci_raw_ops pci_direct_conf2 = {
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	.read =		pci_conf2_read,
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	.write =	pci_conf2_write,
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};
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/*
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 * Before we decide to use direct hardware access mechanisms, we try to do some
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 * trivial checks to ensure it at least _seems_ to be working -- we just test
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 * whether bus 00 contains a host bridge (this is similar to checking
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 * techniques used in XFree86, but ours should be more reliable since we
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 * attempt to make use of direct access hints provided by the PCI BIOS).
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 *
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 * This should be close to trivial, but it isn't, because there are buggy
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 * chipsets (yes, you guessed it, by Intel and Compaq) that have no class ID.
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 */
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static int __init pci_sanity_check(const struct pci_raw_ops *o)
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{
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	u32 x = 0;
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	int year, devfn;
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	if (pci_probe & PCI_NO_CHECKS)
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		return 1;
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	/* Assume Type 1 works for newer systems.
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	   This handles machines that don't have anything on PCI Bus 0. */
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	dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL);
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	if (year >= 2001)
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		return 1;
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	for (devfn = 0; devfn < 0x100; devfn++) {
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		if (o->read(0, 0, devfn, PCI_CLASS_DEVICE, 2, &x))
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			continue;
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		if (x == PCI_CLASS_BRIDGE_HOST || x == PCI_CLASS_DISPLAY_VGA)
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			return 1;
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		if (o->read(0, 0, devfn, PCI_VENDOR_ID, 2, &x))
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			continue;
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		if (x == PCI_VENDOR_ID_INTEL || x == PCI_VENDOR_ID_COMPAQ)
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			return 1;
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	}
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	DBG(KERN_WARNING "PCI: Sanity check failed\n");
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	return 0;
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}
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static int __init pci_check_type1(void)
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{
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	unsigned long flags;
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	unsigned int tmp;
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	int works = 0;
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	local_irq_save(flags);
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	outb(0x01, 0xCFB);
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	tmp = inl(0xCF8);
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	outl(0x80000000, 0xCF8);
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	if (inl(0xCF8) == 0x80000000 && pci_sanity_check(&pci_direct_conf1)) {
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		works = 1;
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	}
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	outl(tmp, 0xCF8);
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	local_irq_restore(flags);
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	return works;
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}
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static int __init pci_check_type2(void)
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{
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	unsigned long flags;
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	int works = 0;
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	local_irq_save(flags);
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	outb(0x00, 0xCFB);
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	outb(0x00, 0xCF8);
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	outb(0x00, 0xCFA);
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	if (inb(0xCF8) == 0x00 && inb(0xCFA) == 0x00 &&
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	    pci_sanity_check(&pci_direct_conf2)) {
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		works = 1;
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	}
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	local_irq_restore(flags);
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	return works;
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}
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void __init pci_direct_init(int type)
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{
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	if (type == 0)
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		return;
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	printk(KERN_INFO "PCI: Using configuration type %d for base access\n",
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		 type);
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	if (type == 1) {
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		raw_pci_ops = &pci_direct_conf1;
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		if (raw_pci_ext_ops)
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			return;
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		if (!(pci_probe & PCI_HAS_IO_ECS))
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			return;
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		printk(KERN_INFO "PCI: Using configuration type 1 "
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		       "for extended access\n");
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		raw_pci_ext_ops = &pci_direct_conf1;
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		return;
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	}
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	raw_pci_ops = &pci_direct_conf2;
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}
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int __init pci_direct_probe(void)
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{
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	if ((pci_probe & PCI_PROBE_CONF1) == 0)
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		goto type2;
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	if (!request_region(0xCF8, 8, "PCI conf1"))
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		goto type2;
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	if (pci_check_type1()) {
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		raw_pci_ops = &pci_direct_conf1;
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		port_cf9_safe = true;
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		return 1;
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	}
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	release_region(0xCF8, 8);
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 type2:
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	if ((pci_probe & PCI_PROBE_CONF2) == 0)
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		return 0;
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	if (!request_region(0xCF8, 4, "PCI conf2"))
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		return 0;
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	if (!request_region(0xC000, 0x1000, "PCI conf2"))
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		goto fail2;
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	if (pci_check_type2()) {
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		raw_pci_ops = &pci_direct_conf2;
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		port_cf9_safe = true;
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		return 2;
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	}
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	release_region(0xC000, 0x1000);
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 fail2:
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	release_region(0xCF8, 4);
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	return 0;
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}
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