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authorMartin Fuzzey <mfuzzey@gmail.com>2009-06-01 09:19:37 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-06-02 22:36:15 +0100
commiteb5f4ca9536ba297c98721ecbbdf41ec5b987bd5 (patch)
treefb1b7dcf66f2f4d00b99776968dca1293f74b8c8 /arch/arm/include/asm/cache.h
parentd9244b5d2fbfe9fa540024b410047af13ceec90f (diff)
downloadblackbird-op-linux-eb5f4ca9536ba297c98721ecbbdf41ec5b987bd5.tar.gz
blackbird-op-linux-eb5f4ca9536ba297c98721ecbbdf41ec5b987bd5.zip
[ARM] 5534/1: kmalloc must return a cache line aligned buffer
Define ARCH_KMALLOC_MINALIGN in asm/cache.h At the request of Russell also move ARCH_SLAB_MINALIGN to this file. Signed-off-by: Martin Fuzzey <mfuzzey@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/cache.h')
-rw-r--r--arch/arm/include/asm/cache.h16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm/include/asm/cache.h b/arch/arm/include/asm/cache.h
index cb7a9e97fd7e..feaa75f0013e 100644
--- a/arch/arm/include/asm/cache.h
+++ b/arch/arm/include/asm/cache.h
@@ -7,4 +7,20 @@
#define L1_CACHE_SHIFT 5
#define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT)
+/*
+ * Memory returned by kmalloc() may be used for DMA, so we must make
+ * sure that all such allocations are cache aligned. Otherwise,
+ * unrelated code may cause parts of the buffer to be read into the
+ * cache before the transfer is done, causing old data to be seen by
+ * the CPU.
+ */
+#define ARCH_KMALLOC_MINALIGN L1_CACHE_BYTES
+
+/*
+ * With EABI on ARMv5 and above we must have 64-bit aligned slab pointers.
+ */
+#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5)
+#define ARCH_SLAB_MINALIGN 8
+#endif
+
#endif
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