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Commit 32544d9c authored by Max Filippov's avatar Max Filippov
Browse files

xtensa: support aliasing cache in k[un]map_atomic 



Map high memory pages at virtual addresses with color that match color
of their physical address. Existing cache alias management mechanisms
may be used with such pages.

Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent a91902db

arch/xtensa/include/asm/fixmap.h

+2 −1
Original line number Diff line number Diff line
@@ -38,7 +38,8 @@ enum fixed_addresses { 
#ifdef CONFIG_HIGHMEM

	/* reserved pte's for temporary kernel mappings */

	FIX_KMAP_BEGIN,

	FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * NR_CPUS) - 1,

	FIX_KMAP_END = FIX_KMAP_BEGIN +

		(KM_TYPE_NR * NR_CPUS * DCACHE_N_COLORS) - 1,

#endif

	__end_of_fixed_addresses

};

arch/xtensa/include/asm/page.h

+2 −0
Original line number Diff line number Diff line
@@ -78,7 +78,9 @@ 
# define DCACHE_ALIAS_EQ(a,b)	((((a) ^ (b)) & DCACHE_ALIAS_MASK) == 0)

#else

# define DCACHE_ALIAS_ORDER	0

# define DCACHE_ALIAS(a)	((void)(a), 0)

#endif

#define DCACHE_N_COLORS		(1 << DCACHE_ALIAS_ORDER)



#if ICACHE_WAY_SIZE > PAGE_SIZE

# define ICACHE_ALIAS_ORDER	(ICACHE_WAY_SHIFT - PAGE_SHIFT)

arch/xtensa/mm/highmem.c

+10 −7
Original line number Diff line number Diff line
@@ -14,18 +14,23 @@ 


static pte_t *kmap_pte;



static inline enum fixed_addresses kmap_idx(int type, unsigned long color)

{

	return (type + KM_TYPE_NR * smp_processor_id()) * DCACHE_N_COLORS +

		color;

}



void *kmap_atomic(struct page *page)

{

	enum fixed_addresses idx;

	unsigned long vaddr;

	int type;



	pagefault_disable();

	if (!PageHighMem(page))

		return page_address(page);



	type = kmap_atomic_idx_push();

	idx = type + KM_TYPE_NR * smp_processor_id();

	idx = kmap_idx(kmap_atomic_idx_push(),

		       DCACHE_ALIAS(page_to_phys(page)));

	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);

#ifdef CONFIG_DEBUG_HIGHMEM

	BUG_ON(!pte_none(*(kmap_pte + idx)));
@@ -38,12 +43,10 @@ EXPORT_SYMBOL(kmap_atomic); 


void __kunmap_atomic(void *kvaddr)

{

	int idx, type;



	if (kvaddr >= (void *)FIXADDR_START &&

	    kvaddr < (void *)FIXADDR_TOP) {

		type = kmap_atomic_idx();

		idx = type + KM_TYPE_NR * smp_processor_id();

		int idx = kmap_idx(kmap_atomic_idx(),

				   DCACHE_ALIAS((unsigned long)kvaddr));



		/*

		 * Force other mappings to Oops if they'll try to access this