drivers/pci: Create pci_map_bar function

It is no longer always true that the pci bus address can be
used as the virtual address for pci accesses.  pci_map_bar()
is created to return the virtual address for a pci region.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
This commit is contained in:
Becky Bruce
2009-02-03 18:10:50 -06:00
committed by Wolfgang Denk
parent 2ecca34017
commit 6e61fae4d3
2 changed files with 43 additions and 4 deletions

View File

@ -116,6 +116,25 @@ PCI_READ_VIA_DWORD_OP(word, u16 *, 0x02)
PCI_WRITE_VIA_DWORD_OP(byte, u8, 0x03, 0x000000ff)
PCI_WRITE_VIA_DWORD_OP(word, u16, 0x02, 0x0000ffff)
/* Get a virtual address associated with a BAR region */
void *pci_map_bar(pci_dev_t pdev, int bar, int flags)
{
pci_addr_t pci_bus_addr;
u32 bar_response;
/* read BAR address */
pci_read_config_dword(pdev, bar, &bar_response);
pci_bus_addr = (pci_addr_t)(bar_response & ~0xf);
/*
* Pass "0" as the length argument to pci_bus_to_virt. The arg
* isn't actualy used on any platform because u-boot assumes a static
* linear mapping. In the future, this could read the BAR size
* and pass that as the size if needed.
*/
return pci_bus_to_virt(pdev, pci_bus_addr, flags, 0, MAP_NOCACHE);
}
/*
*
*/