Re: [PATCH 2/2] x86: gart alloc_coherent does virtual mapppings only when necessary

From: Joerg Roedel
Date: Thu Sep 11 2008 - 10:16:45 EST


Looks good to me.

On Thu, Sep 11, 2008 at 11:08:48PM +0900, FUJITA Tomonori wrote:
> gart alloc_coherent need to do virtual mapppings only when an
> allocated buffer is not DMA-capable for a device.
>
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
> Cc: Joerg Roedel <joerg.roedel@xxxxxxx>

Acked-by: Joerg Roedel <joerg.roedel@xxxxxxx>

> ---
> arch/x86/kernel/pci-gart_64.c | 10 +++++++++-
> 1 files changed, 9 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
> index 1b0c412..47abe43 100644
> --- a/arch/x86/kernel/pci-gart_64.c
> +++ b/arch/x86/kernel/pci-gart_64.c
> @@ -488,15 +488,23 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr,
> gfp_t flag)
> {
> void *vaddr;
> + dma_addr_t paddr;
> unsigned long align_mask;
> + u64 dma_mask = dma_alloc_coherent_mask(dev, flag);
>
> vaddr = (void *)__get_free_pages(flag | __GFP_ZERO, get_order(size));
> if (!vaddr)
> return NULL;
>
> + paddr = virt_to_phys(vaddr);
> + if (is_buffer_dma_capable(dma_mask, paddr, size)) {
> + *dma_addr = paddr;
> + return vaddr;
> + }
> +
> align_mask = (1UL << get_order(size)) - 1;
>
> - *dma_addr = dma_map_area(dev, __pa(vaddr), size, DMA_BIDIRECTIONAL,
> + *dma_addr = dma_map_area(dev, paddr, size, DMA_BIDIRECTIONAL,
> align_mask);
> flush_gart();
>
> --
> 1.5.4.2
>
>

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