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pci: add pci_iomap_range 

Virtio drivers should map the part of the BAR they need, not necessarily
all of it.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Michael S. Tsirkin 2013-05-29 11:52:21 +09:30 committed by Rusty Russell
parent 54cfe08b5f
commit eb29d8d2aa
2 changed files with 53 additions and 18 deletions
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10
include/asm-generic/pci_iomap.h
View File

@ -15,6 +15,9 @@ struct pci_dev;
#ifdef CONFIG_PCI
/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
extern void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
unsigned long offset,
unsigned long maxlen);
/* Create a virtual mapping cookie for a port on a given PCI device.
* Do not call this directly, it exists to make it easier for architectures
* to override */
@ -30,6 +33,13 @@ static inline void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned lon
{
return NULL;
}
static inline void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
unsigned long offset,
unsigned long maxlen)
{
return NULL;
}
#endif
#endif /* __ASM_GENERIC_IO_H */

61
lib/pci_iomap.c
View File

@ -9,6 +9,48 @@
#include <linux/export.h>
#ifdef CONFIG_PCI
/**
* pci_iomap_range - create a virtual mapping cookie for a PCI BAR
* @dev: PCI device that owns the BAR
* @bar: BAR number
* @offset: map memory at the given offset in BAR
* @maxlen: max 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 from offset to the end, pass %0 here.
* */
void __iomem *pci_iomap_range(struct pci_dev *dev,
int bar,
unsigned long offset,
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 <= offset || !start)
return NULL;
len -= offset;
start += offset;
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_range);
/**
* pci_iomap - create a virtual mapping cookie for a PCI BAR
* @dev: PCI device that owns the BAR
@ -25,24 +67,7 @@
* */
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;
return pci_iomap_range(dev, bar, 0, maxlen);
}
EXPORT_SYMBOL(pci_iomap);
#endif /* CONFIG_PCI */