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authorMikulas Patocka <mpatocka@redhat.com>2024-07-27 20:22:52 +0200
committerHelge Deller <deller@gmx.de>2024-07-29 16:19:07 +0200
commit7ae04ba36b381bffe2471eff3a93edced843240f (patch)
tree21ffe22db1baa2cfa54ac2feffca011bffc94c9f /arch/parisc
parent1fd2c10acb7b35d72101a4619ee5b2cddb9efd3a (diff)
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parisc: fix a possible DMA corruption
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@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc')
-rw-r--r--arch/parisc/Kconfig1
-rw-r--r--arch/parisc/include/asm/cache.h11
2 files changed, 11 insertions, 1 deletions
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 5d650e02cbf4..b0a2ac3ba916 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -20,6 +20,7 @@ config PARISC
select ARCH_SUPPORTS_HUGETLBFS if PA20
select ARCH_SUPPORTS_MEMORY_FAILURE
select ARCH_STACKWALK
+ select ARCH_HAS_CACHE_LINE_SIZE
select ARCH_HAS_DEBUG_VM_PGTABLE
select HAVE_RELIABLE_STACKTRACE
select DMA_OPS
diff --git a/arch/parisc/include/asm/cache.h b/arch/parisc/include/asm/cache.h
index 2a60d7a72f1f..a3f0f100f219 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")