alistair23-linux/lib/pci_iomap.c
Michael S. Tsirkin b923650b84 lib: add NO_GENERIC_PCI_IOPORT_MAP
Some architectures need to override the way
IO port mapping is done on PCI devices.
Supply a generic macro that calls
ioport_map, and make it possible for architectures
to override.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-01-31 23:19:47 +02:00

49 lines
1.4 KiB
C

/*
* Implement the default iomap interfaces
*
* (C) Copyright 2004 Linus Torvalds
*/
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/export.h>
#ifdef CONFIG_PCI
/**
* pci_iomap - create a virtual mapping cookie for a PCI BAR
* @dev: PCI device that owns the BAR
* @bar: BAR number
* @maxlen: length of the memory to map
*
* Using this function you will get a __iomem address to your device BAR.
* You can access it using ioread*() and iowrite*(). These functions hide
* the details if this is a MMIO or PIO address space and will just do what
* you expect from them in the correct way.
*
* @maxlen specifies the maximum length to map. If you want to get access to
* the complete BAR without checking for its length first, pass %0 here.
* */
void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
{
resource_size_t start = pci_resource_start(dev, bar);
resource_size_t len = pci_resource_len(dev, bar);
unsigned long flags = pci_resource_flags(dev, bar);
if (!len || !start)
return NULL;
if (maxlen && len > maxlen)
len = maxlen;
if (flags & IORESOURCE_IO)
return __pci_ioport_map(dev, start, len);
if (flags & IORESOURCE_MEM) {
if (flags & IORESOURCE_CACHEABLE)
return ioremap(start, len);
return ioremap_nocache(start, len);
}
/* What? */
return NULL;
}
EXPORT_SYMBOL(pci_iomap);
#endif /* CONFIG_PCI */