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Commit 376e1421 authored by Catalin Marinas's avatar Catalin Marinas
Browse files

Do not flush the cache in flush_cache_v(un)map for VIPT caches 



In case of non-aliasing VIPT caches, there is no need to flush the whole
cache when new mapping is created. The patch introduces this condition
check. In the non-aliasing VIPT case flush_cache_vmap() needs a DSB
since the set_pte_at() function called from vmap_pte_range() does not
have such barrier (done usually via TLB flushing functions).

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 24b647a0

arch/arm/include/asm/cacheflush.h

+26 −10
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 


#include <asm/glue.h>

#include <asm/shmparam.h>

#include <asm/cachetype.h>



#define CACHE_COLOUR(vaddr)	((vaddr & (SHMLBA - 1)) >> PAGE_SHIFT)
@@ -295,16 +296,6 @@ static inline void outer_flush_range(unsigned long start, unsigned long end) 


#endif



/*

 * flush_cache_vmap() is used when creating mappings (eg, via vmap,

 * vmalloc, ioremap etc) in kernel space for pages.  Since the

 * direct-mappings of these pages may contain cached data, we need

 * to do a full cache flush to ensure that writebacks don't corrupt

 * data placed into these pages via the new mappings.

 */

#define flush_cache_vmap(start, end)		flush_cache_all()

#define flush_cache_vunmap(start, end)		flush_cache_all()



/*

 * Copy user data from/to a page which is mapped into a different

 * processes address space.  Really, we want to allow our "user
@@ -444,4 +435,29 @@ static inline void flush_ioremap_region(unsigned long phys, void __iomem *virt, 
	dmac_inv_range(start, start + size);

}



/*

 * flush_cache_vmap() is used when creating mappings (eg, via vmap,

 * vmalloc, ioremap etc) in kernel space for pages.  On non-VIPT

 * caches, since the direct-mappings of these pages may contain cached

 * data, we need to do a full cache flush to ensure that writebacks

 * don't corrupt data placed into these pages via the new mappings.

 */

static inline void flush_cache_vmap(unsigned long start, unsigned long end)

{

	if (!cache_is_vipt_nonaliasing())

		flush_cache_all();

	else

		/*

		 * set_pte_at() called from vmap_pte_range() does not

		 * have a DSB after cleaning the cache line.

		 */

		dsb();

}



static inline void flush_cache_vunmap(unsigned long start, unsigned long end)

{

	if (!cache_is_vipt_nonaliasing())

		flush_cache_all();

}



#endif