On 10:20 Sat 06 Dec , Ralf Baechle wrote:
> On Fri, Dec 05, 2008 at 11:43:42PM +0800, Zhang Le wrote:
> > I have tried xorg-server-1.5.2 on loongson 2f recently.
> > But I found it doesn't work.
> > It's mainly because of this change:
> > http://www.x.org/wiki/PciReworkProposal
> > In short:
> > "Rather than duplicating the efforts of kernel developers, X.org needs to
> > use the
> > interfaces provided by the kernel as much as possible."
> > I have read some code of libpciaccess, the new library utilizing kernel
> > function
> > to access pci bus. It will try to mmap this file:
> > /sys/bus/pci/devices/0000:0x:xx.x/resource0
> > (replace x with any digit appropriate)
> > Note there is a 0 at the end of the file name. This file's permission is
> > 600.
> > However, I found on my loongson system, there is only
> > /sys/bus/pci/devices/0000:0x:xx.x/resource
> > Note there is no 0 at the end.
> > Then I tried to read kernel code. I found it seems that for mips linux to
> > have
> > this file, HAVE_PCI_MMAP must be defined. However, it is currently not
> > defined.
> > Since I am not familiar with PCI, yet.
> > So could someone please shed some light on this?
> > Why HAVE_PCI_MMAP is not defined?
> Here is a quick'n'dirty solution which I've not tested beyond just
> compiling. It should work but performance will be bad. Either way, I'm
> interested in a test report with X.
I will test it.
> Signed-off-by: Ralf Baechle <email@example.com>
> diff --git a/arch/mips/include/asm/pci.h b/arch/mips/include/asm/pci.h
> index 5510c53..053e463 100644
> --- a/arch/mips/include/asm/pci.h
> +++ b/arch/mips/include/asm/pci.h
> @@ -79,6 +79,11 @@ static inline void pcibios_penalize_isa_irq(int irq, int
> /* We don't do dynamic PCI IRQ allocation */
> +#define HAVE_PCI_MMAP
> +extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct
> + enum pci_mmap_state mmap_state, int write_combine);
> * Dynamic DMA mapping stuff.
> * MIPS has everything mapped statically.
> diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c
> index a377e9d..9233193 100644
> --- a/arch/mips/pci/pci.c
> +++ b/arch/mips/pci/pci.c
> @@ -354,6 +354,22 @@ EXPORT_SYMBOL(PCIBIOS_MIN_IO);
> +int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
> + enum pci_mmap_state mmap_state, int write_combine)
> + unsigned long prot;
> + /*
> + * Ignore write-combine; for now only return uncached mappings.
> + */
> + prot = pgprot_val(vma->vm_page_prot);
> + prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;
> + vma->vm_page_prot = __pgprot(prot);
> + return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
> + vma->vm_end - vma->vm_start, vma->vm_page_prot);
> char * (*pcibios_plat_setup)(char *str) __devinitdata;
> char *__devinit pcibios_setup(char *str)