Messages in this thread |  | | Subject | Re: Physical memory addresses/PCI memory addresses/io_remap | Date | Thu, 14 Dec 2000 18:37:22 +0000 (GMT) | From | Alan Cox <> |
| |
> > 1. Should pci_resource_start be returning the PCI memory space address or > > a physical memory space address? > > I believe that pci_resource_start() should return physical address, not > bus one. It already happens on PReP.
It returns a cookie for use with ioremap. Who says that a given device has a constant bus or physical mapping that is unique ?
> > 4. What does this mean for ioremap? (currently, on ARM, ioremap takes > > PCI memory space addresses, not a physical memory address, which makes > > the physmap MTD driver technically broken). > > And ioremap() should take physical address, returning virtual one.
No. Ioremap takes a cookie and returns a different cookie suitable for using with readb/writeb/memcpy_fromio and friends.
Eg on Sparc64 its a physical address and readb uses TLB bypass
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
|  |