Messages in this thread Patch in this message | | | Date | Fri, 8 Mar 2013 09:51:17 +0900 | From | Joonsoo Kim <> | Subject | Re: [PATCH] ARM: mm: clean-up in order to reduce to call kmap_high_get() |
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Hello, Russell.
On Thu, Mar 07, 2013 at 01:26:23PM +0000, Russell King - ARM Linux wrote: > On Mon, Mar 04, 2013 at 01:50:09PM +0900, Joonsoo Kim wrote: > > In kmap_atomic(), kmap_high_get() is invoked for checking already > > mapped area. In __flush_dcache_page() and dma_cache_maint_page(), > > we explicitly call kmap_high_get() before kmap_atomic() > > when cache_is_vipt(), so kmap_high_get() can be invoked twice. > > This is useless operation, so remove one. > > > > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> > > > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > > index c7e3759..b7711be 100644 > > --- a/arch/arm/mm/dma-mapping.c > > +++ b/arch/arm/mm/dma-mapping.c > > @@ -822,16 +822,16 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, > > if (PageHighMem(page)) { > > if (len + offset > PAGE_SIZE) > > len = PAGE_SIZE - offset; > > - vaddr = kmap_high_get(page); > > - if (vaddr) { > > - vaddr += offset; > > - op(vaddr, len, dir); > > - kunmap_high(page); > > - } else if (cache_is_vipt()) { > > - /* unmapped pages might still be cached */ > > + if (cache_is_vipt()) { > > This should be: > if (cache_is_vipt_nonaliasing()) > > to make it _explicit_ that this technique is only for non-aliasing VIPT > caches (this doesn't work on any other of our cache types.) Yes, I > know we don't support highmem with VIPT aliasing caches - but still, > we should ensure that this is self-documented in this code. > > Same for arch/arm/mm/flush.c
Okay. I will re-work and will send v2 soon.
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