Messages in this thread | | | Date | Tue, 07 Sep 2010 13:11:28 +0400 | From | Sergei Shtylyov <> | Subject | Re: [PATCH 1/5] MIPS: HIGHMEM DMA on noncoherent MIPS32 processors |
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Hello.
On 07-09-2010 8:03, Kevin Cernekee wrote:
> The MIPS DMA coherency functions do not work properly (i.e. kernel oops) > when HIGHMEM pages are passed in as arguments. This patch uses the PPC > approach of calling kmap_atomic() with IRQs disabled to temporarily map > high pages, in order to flush them out to memory.
> Signed-off-by: Dezhong Diao <dediao@cisco.com> > Signed-off-by: Kevin Cernekee <cernekee@gmail.com> > --- > arch/mips/mm/dma-default.c | 159 ++++++++++++++++++++++---------------------- > 1 files changed, 80 insertions(+), 79 deletions(-)
> diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c > index 469d401..3f23952 100644 > --- a/arch/mips/mm/dma-default.c > +++ b/arch/mips/mm/dma-default.c [...] > @@ -191,8 +231,8 @@ void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size, > enum dma_data_direction direction) > { > if (cpu_is_noncoherent_r10000(dev)) > - __dma_sync(dma_addr_to_virt(dev, dma_addr), size, > - direction); > + __dma_sync(dma_addr_to_page(dev, dma_addr), > + (dma_addr & ~PAGE_MASK), size, direction);
Parens are not needed here.
> @@ -277,15 +297,10 @@ EXPORT_SYMBOL(dma_sync_single_for_cpu); > void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, > size_t size, enum dma_data_direction direction) > { > - BUG_ON(direction == DMA_NONE); > - > plat_extra_sync_for_device(dev); > - if (!plat_device_is_coherent(dev)) { > - unsigned long addr; > - > - addr = dma_addr_to_virt(dev, dma_handle); > - __dma_sync(addr, size, direction); > - } > + if (!plat_device_is_coherent(dev)) > + __dma_sync(dma_addr_to_page(dev, dma_handle), > + (dma_handle & ~PAGE_MASK), size, direction);
Here as well...
WBR, Sergei
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