Re: [PATCH 2.6.15-rc4 1/1] cpia: use vm_insert_page() instead of remap_pfn_range()

[Nick Piggin <nickpiggin@yahoo.com.au>]

Nick Holloway wrote:
> On Tue, Dec 06, 2005 at 07:10:12PM +0000, Christoph Hellwig wrote:
>
> > >    pos = (unsigned long)(cam->frame_buf);
> > >    while (size > 0) {
> > > -           page = vmalloc_to_pfn((void *)pos);
> > > -           if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) {
> > > +           page = vmalloc_to_page((void *)pos);
> > > +           if (vm_insert_page(vma, start, page)) {
> >
> > it would be nicer to do the arithmetis on pos as pointers rather than unsigned
> > long.  Also you might want to use alloc_pages + vmap instead of vmalloc so that
> > you already have a page array.  Or we should provide a helper that walks over
> > a vmalloc'ed region and calls vmalloc_to_page + vm_insert_page.  Either way
> > this type of code is duplicated far too much and we'd really need some better
> > interface for it.
>
>
> As I said in my previous mail, the patch was just switching to use
> vm_insert_page, and not any other cleanups.
>
> I agree that a helper is a good idea, as the vmalloc, SetPageReserved,
> remap_pfn_range (was remap_page_range in 2.4) pattern has been copied
> and pasted across many video4linux drivers.
>
> The cpia driver could do with other cleanups.
>
>         - It doesn't have a sysfs release callback (so says warning printk).
> 	- The colourspace conversion has been disabled, but should be
> 	  ripped out.
> 	- Needs to support V4L2 API

- remove the last traces of rvmalloc (which is an oft repeated code
  sequence in drivers, means something like vmalloc + SetPageReserved)

--
SUSE Labs, Novell Inc.

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