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xtensa: support aliasing cache in k[un]map_atomic

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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: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov 2014-07-15 02:51:49 +04:00
parent a91902db29
commit 32544d9c10
3 changed files with 14 additions and 8 deletions
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3
arch/xtensa/include/asm/fixmap.h
View File

@ -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
};

2
arch/xtensa/include/asm/page.h
View File

@ -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)

17
arch/xtensa/mm/highmem.c
View File

@ -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