diff options
Diffstat (limited to 'include/asm-sh/page.h')
| -rw-r--r-- | include/asm-sh/page.h | 22 |
1 files changed, 9 insertions, 13 deletions
diff --git a/include/asm-sh/page.h b/include/asm-sh/page.h index 407bf5a1493..bff635a078c 100644 --- a/include/asm-sh/page.h +++ b/include/asm-sh/page.h @@ -138,22 +138,18 @@ typedef struct { unsigned long pgd; } pgd_t; #endif /* - * Slub defaults to 8-byte alignment, we're only interested in 4. - * Slab defaults to BYTES_PER_WORD, which ends up being the same anyways. + * Some drivers need to perform DMA into kmalloc'ed buffers + * and so we have to increase the kmalloc minalign for this. */ -#ifdef CONFIG_SUPERH32 -#define ARCH_KMALLOC_MINALIGN 4 -#define ARCH_SLAB_MINALIGN 4 -#else -/* If gcc inlines memset, it will use st.q instructions. Therefore, we need - kmalloc allocations to be 8-byte aligned. Without this, the alignment - becomes BYTE_PER_WORD i.e. only 4 (since sizeof(long)==sizeof(void*)==4 on - sh64 at the moment). */ -#define ARCH_KMALLOC_MINALIGN 8 +#define ARCH_KMALLOC_MINALIGN L1_CACHE_BYTES +#ifdef CONFIG_SUPERH64 /* - * We want 8-byte alignment for the slab caches as well, otherwise we have - * the same BYTES_PER_WORD (sizeof(void *)) min align in kmem_cache_create(). + * While BYTES_PER_WORD == 4 on the current sh64 ABI, GCC will still + * happily generate {ld/st}.q pairs, requiring us to have 8-byte + * alignment to avoid traps. The kmalloc alignment is gauranteed by + * virtue of L1_CACHE_BYTES, requiring this to only be special cased + * for slab caches. */ #define ARCH_SLAB_MINALIGN 8 #endif |