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| author | Akinobu Mita <akinobu.mita@gmail.com> | 2013-03-29 03:44:43 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-03-31 19:29:12 -0400 |
| commit | 54df2db36c93bbb8c757f172d97c577040de6abb (patch) | |
| tree | 201c8a8217ef40e4fc5eeb8e7b3c5f17ad96b29c | |
| parent | 71196a26d85be2aae2e587dfd3c3190a651133c6 (diff) | |
| download | lwn-54df2db36c93bbb8c757f172d97c577040de6abb.tar.gz lwn-54df2db36c93bbb8c757f172d97c577040de6abb.zip | |
sparc/srmmu: clear trailing edge of bitmap properly
srmmu_nocache_bitmap is cleared by bit_map_init(). But bit_map_init()
attempts to clear by memset(), so it can't clear the trailing edge of
bitmap properly on big-endian architecture if the number of bits is not
a multiple of BITS_PER_LONG.
Actually, the number of bits in srmmu_nocache_bitmap is not always
a multiple of BITS_PER_LONG. It is calculated as below:
bitmap_bits = srmmu_nocache_size >> SRMMU_NOCACHE_BITMAP_SHIFT;
srmmu_nocache_size is decided proportionally by the amount of system RAM
and it is rounded to a multiple of PAGE_SIZE. SRMMU_NOCACHE_BITMAP_SHIFT
is defined as (PAGE_SHIFT - 4). So it can only be said that bitmap_bits
is a multiple of 16.
This fixes the problem by using bitmap_clear() instead of memset()
in bit_map_init() and this also uses BITS_TO_LONGS() to calculate correct
size at bitmap allocation time.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | arch/sparc/lib/bitext.c | 6 | ||||
| -rw-r--r-- | arch/sparc/mm/srmmu.c | 4 |
2 files changed, 4 insertions, 6 deletions
diff --git a/arch/sparc/lib/bitext.c b/arch/sparc/lib/bitext.c index 48d00e72ce15..8ec4e9c0251a 100644 --- a/arch/sparc/lib/bitext.c +++ b/arch/sparc/lib/bitext.c @@ -119,11 +119,7 @@ void bit_map_clear(struct bit_map *t, int offset, int len) void bit_map_init(struct bit_map *t, unsigned long *map, int size) { - - if ((size & 07) != 0) - BUG(); - memset(map, 0, size>>3); - + bitmap_zero(map, size); memset(t, 0, sizeof *t); spin_lock_init(&t->lock); t->map = map; diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c index c38bb72e3e80..036c2797dece 100644 --- a/arch/sparc/mm/srmmu.c +++ b/arch/sparc/mm/srmmu.c @@ -280,7 +280,9 @@ static void __init srmmu_nocache_init(void) SRMMU_NOCACHE_ALIGN_MAX, 0UL); memset(srmmu_nocache_pool, 0, srmmu_nocache_size); - srmmu_nocache_bitmap = __alloc_bootmem(bitmap_bits >> 3, SMP_CACHE_BYTES, 0UL); + srmmu_nocache_bitmap = + __alloc_bootmem(BITS_TO_LONGS(bitmap_bits) * sizeof(long), + SMP_CACHE_BYTES, 0UL); bit_map_init(&srmmu_nocache_map, srmmu_nocache_bitmap, bitmap_bits); srmmu_swapper_pg_dir = __srmmu_get_nocache(SRMMU_PGD_TABLE_SIZE, SRMMU_PGD_TABLE_SIZE); |