Re: [PATCH 4/5] swiotlb: map_page fix for highmem systems

FUJITA Tomonori
2009-03-25T03:07:40Z

On Tue, 24 Mar 2009 16:28:45 -0500
Becky Bruce <beckyb@kernel.crashing.org> wrote:

> The current code calls virt_to_phys() on address that might
> be in highmem, which is bad. This wasn't needed, anyway, because
> we already have the physical address we need. Get rid of the
> now-unused virtual address as well.
>
> Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
> ---
> lib/swiotlb.c | 3 +--
> 1 files changed, 1 insertions(+), 2 deletions(-)
>
> diff --git a/lib/swiotlb.c b/lib/swiotlb.c
> index c152f17..b33180e 100644
> --- a/lib/swiotlb.c
> +++ b/lib/swiotlb.c
> @@ -640,7 +640,6 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
> struct dma_attrs *attrs)
> {
> phys_addr_t phys = page_to_phys(page) + offset;
> - void *ptr = page_address(page) + offset;
> dma_addr_t dev_addr = swiotlb_phys_to_bus(dev, phys);
> void *map;
>
> @@ -651,7 +650,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
> * buffering it.
> */
> if (!address_needs_mapping(dev, dev_addr, size) &&
> - !range_needs_mapping(virt_to_phys(ptr), size))
> + !range_needs_mapping(phys, size))
> return dev_addr;

Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>