From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
[ Upstream commit 7ae04ba36b381bffe2471eff3a93edced843240f]
ARCH_DMA_MINALIGN was defined as 16 - this is too small - it may be
possible that two unrelated 16-byte allocations share a cache line. If
one of these allocations is written using DMA and the other is written
using cached write, the value that was written with DMA may be
corrupted.
This commit changes ARCH_DMA_MINALIGN to be 128 on PA20 and 32 on PA1.1 -
that's the largest possible cache line size.
As different parisc microarchitectures have different cache line size, we
define arch_slab_minalign(), cache_line_size() and
dma_get_cache_alignment() so that the kernel may tune slab cache
parameters dynamically, based on the detected cache line size.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Mingli Yu <mingli.yu@xxxxxxxxxxxxx>
---
arch/parisc/Kconfig | 1 +
arch/parisc/include/asm/cache.h | 11 ++++++++++-
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 6ac0c4b98e28..9888e0b3f675 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -15,6 +15,7 @@ config PARISC
select ARCH_SPLIT_ARG64 if !64BIT
select ARCH_SUPPORTS_HUGETLBFS if PA20
select ARCH_SUPPORTS_MEMORY_FAILURE
+ select ARCH_HAS_CACHE_LINE_SIZE
select DMA_OPS
select RTC_CLASS
select RTC_DRV_GENERIC
diff --git a/arch/parisc/include/asm/cache.h b/arch/parisc/include/asm/cache.h
index d53e9e27dba0..99e26c686f7f 100644
--- a/arch/parisc/include/asm/cache.h
+++ b/arch/parisc/include/asm/cache.h
@@ -20,7 +20,16 @@
#define SMP_CACHE_BYTES L1_CACHE_BYTES
-#define ARCH_DMA_MINALIGN L1_CACHE_BYTES
+#ifdef CONFIG_PA20
+#define ARCH_DMA_MINALIGN 128
+#else
+#define ARCH_DMA_MINALIGN 32
+#endif
+#define ARCH_KMALLOC_MINALIGN 16 /* ldcw requires 16-byte alignment */
+
+#define arch_slab_minalign() ((unsigned)dcache_stride)
+#define cache_line_size() dcache_stride
+#define dma_get_cache_alignment cache_line_size
#define __read_mostly __section(".data..read_mostly")
--
2.34.1
