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/*
* $Id: pci.c,v 1.91 1999/01/21 13:34:01 davem Exp $
*
* PCI Bus Services, see include/linux/pci.h for further explanation.
*
* Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
* David Mosberger-Tang
*
* Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
*/
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <asm/dma.h> /* isa_dma_bridge_buggy */
#include "pci.h"
/**
* pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
* @bus: pointer to PCI bus structure to search
*
* Given a PCI bus, returns the highest PCI bus number present in the set
* including the given PCI bus and its list of child PCI buses.
*/
unsigned char __devinit
pci_bus_max_busnr(struct pci_bus* bus)
{
struct list_head *tmp;
unsigned char max, n;
max = bus->subordinate;
list_for_each(tmp, &bus->children) {
n = pci_bus_max_busnr(pci_bus_b(tmp));
if(n > max)
max = n;
}
return max;
}
EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
#if 0
/**
* pci_max_busnr - returns maximum PCI bus number
*
* Returns the highest PCI bus number present in the system global list of
* PCI buses.
*/
unsigned char __devinit
pci_max_busnr(void)
{
struct pci_bus *bus = NULL;
unsigned char max, n;
max = 0;
while ((bus = pci_find_next_bus(bus)) != NULL) {
n = pci_bus_max_busnr(bus);
if(n > max)
max = n;
}
return max;
}
#endif /* 0 */
static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn, u8 pos, int cap)
{
u8 id;
int ttl = 48;
while (ttl--) {
pci_bus_read_config_byte(bus, devfn, pos, &pos);
if (pos < 0x40)
break;
pos &= ~3;
pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID,
&id);
if (id == 0xff)
break;
if (id == cap)
return pos;
pos += PCI_CAP_LIST_NEXT;
}
return 0;
}
int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
{
return __pci_find_next_cap(dev->bus, dev->devfn,
pos + PCI_CAP_LIST_NEXT, cap);
}
EXPORT_SYMBOL_GPL(pci_find_next_capability);
static int __pci_bus_find_cap(struct pci_bus *bus, unsigned int devfn, u8 hdr_type, int cap)
{
u16 status;
u8 pos;
pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
if (!(status & PCI_STATUS_CAP_LIST))
return 0;
switch (hdr_type) {
case PCI_HEADER_TYPE_NORMAL:
case PCI_HEADER_TYPE_BRIDGE:
pos = PCI_CAPABILITY_LIST;
break;
case PCI_HEADER_TYPE_CARDBUS:
pos = PCI_CB_CAPABILITY_LIST;
break;
default:
return 0;
}
return __pci_find_next_cap(bus, devfn, pos, cap);
}
/**
* pci_find_capability - query for devices' capabilities
* @dev: PCI device to query
* @cap: capability code
*
* Tell if a device supports a given PCI capability.
* Returns the address of the requested capability structure within the
* device's PCI configuration space or 0 in case the device does not
* support it. Possible values for @cap:
*
* %PCI_CAP_ID_PM Power Management
* %PCI_CAP_ID_AGP Accelerated Graphics Port
* %PCI_CAP_ID_VPD Vital Product Data
* %PCI_CAP_ID_SLOTID Slot Identification
* %PCI_CAP_ID_MSI Message Signalled Interrupts
* %PCI_CAP_ID_CHSWP CompactPCI HotSwap
* %PCI_CAP_ID_PCIX PCI-X
* %PCI_CAP_ID_EXP PCI Express
*/
int pci_find_capability(struct pci_dev *dev, int cap)
{
return __pci_bus_find_cap(dev->bus, dev->devfn, dev->hdr_type, cap);
}
/**
* pci_bus_find_capability - query for devices' capabilities
* @bus: the PCI bus to query
* @devfn: PCI device to query
* @cap: capability code
*
* Like pci_find_capability() but works for pci devices that do not have a
* pci_dev structure set up yet.
*
* Returns the address of the requested capability structure within the
* device's PCI configuration space or 0 in case the device does not
* support it.
*/
int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap)
{
u8 hdr_type;
pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type);
return __pci_bus_find_cap(bus, devfn, hdr_type & 0x7f, cap);
}
/**
* pci_find_ext_capability - Find an extended capability
* @dev: PCI device to query
* @cap: capability code
*
* Returns the address of the requested extended capability structure
* within the device's PCI configuration space or 0 if the device does
* not support it. Possible values for @cap:
*
* %PCI_EXT_CAP_ID_ERR Advanced Error Reporting
* %PCI_EXT_CAP_ID_VC Virtual Channel
* %PCI_EXT_CAP_ID_DSN Device Serial Number
* %PCI_EXT_CAP_ID_PWR Power Budgeting
*/
int pci_find_ext_capability(struct pci_dev *dev, int cap)
{
u32 header;
int ttl = 480; /* 3840 bytes, minimum 8 bytes per capability */
int pos = 0x100;
if (dev->cfg_size <= 256)
return 0;
if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL)
return 0;
/*
* If we have no capabilities, this is indicated by cap ID,
* cap version and next pointer all being 0.
*/
if (header == 0)
return 0;
while (ttl-- > 0) {
if (PCI_EXT_CAP_ID(header) == cap)
return pos;
pos = PCI_EXT_CAP_NEXT(header);
if (pos
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