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Commit ee6a7fce authored by Catalin Marinas's avatar Catalin Marinas
Browse files

arm64: Remove I-cache invalidation from flush_cache_range() 



The flush_cache_range() function (similarly for flush_cache_page()) is
called when the kernel is changing an existing VA->PA mapping range to
either a new PA or to different attributes. Since ARMv8 has PIPT-like
D-caches, this function does not need to perform any D-cache
maintenance. The I-cache maintenance is already handled via set_pte_at()
and flush_cache_range() cannot anyway guarantee that there are no cache
lines left after invalidation due to the speculative loads.

This patch makes flush_cache_range() a no-op.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 833a9f4b

arch/arm64/include/asm/cacheflush.h

+5 −1
Original line number Diff line number Diff line
@@ -65,7 +65,6 @@ 
 *		- kaddr  - page address

 *		- size   - region size

 */

extern void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end);

extern void flush_icache_range(unsigned long start, unsigned long end);

extern void __flush_dcache_area(void *addr, size_t len);

extern void __clean_dcache_area_poc(void *addr, size_t len);
@@ -82,6 +81,11 @@ static inline void flush_cache_page(struct vm_area_struct *vma, 
{

}



static inline void flush_cache_range(struct vm_area_struct *vma,

				     unsigned long start, unsigned long end)

{

}



/*

 * Cache maintenance functions used by the DMA API. No to be used directly.

 */

arch/arm64/mm/flush.c

+0 −7
Original line number Diff line number Diff line
@@ -25,13 +25,6 @@ 
#include <asm/cachetype.h>

#include <asm/tlbflush.h>



void flush_cache_range(struct vm_area_struct *vma, unsigned long start,

		       unsigned long end)

{

	if (vma->vm_flags & VM_EXEC)

		__flush_icache_all();

}



void sync_icache_aliases(void *kaddr, unsigned long len)

{

	unsigned long addr = (unsigned long)kaddr;