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authorPaul Mundt <lethal@linux-sh.org>2007-11-27 15:57:30 +0900
committerPaul Mundt <lethal@linux-sh.org>2008-01-28 13:18:58 +0900
commit66d485b45a5493f6a2ca067c6f472e7b2ca342c2 (patch)
treecda9d1614122fe5183ce2b1f26f630aa0558f01e
parenteddeeb32fe303910c58c4e3c27fde4b6f1503350 (diff)
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op-kernel-dev-66d485b45a5493f6a2ca067c6f472e7b2ca342c2.tar.gz
sh: Bump up ARCH_KMALLOC_MINALIGN for DMA cases.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
-rw-r--r--include/asm-sh/page.h22
1 files changed, 9 insertions, 13 deletions
diff --git a/include/asm-sh/page.h b/include/asm-sh/page.h
index 407bf5a..bff635a 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
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