From: Mikulas Patocka mpatocka@redhat.com
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 Signed-off-by: Bin Lan bin.lan.cn@windriver.com --- 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 3341d4a42199..3a32b49d7ad0 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -18,6 +18,7 @@ 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 e23d06b51a20..91e753f08eaa 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")
On Tue, Nov 19, 2024 at 01:49:33PM +0800, Bin Lan wrote:
From: Mikulas Patocka mpatocka@redhat.com
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 Signed-off-by: Bin Lan bin.lan.cn@windriver.com
arch/parisc/Kconfig | 1 + arch/parisc/include/asm/cache.h | 11 ++++++++++- 2 files changed, 11 insertions(+), 1 deletion(-)
You seem to have forgotten to add the git id :(
On 11/19/2024 9:15 PM, Greg KH wrote:
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On Tue, Nov 19, 2024 at 01:49:33PM +0800, Bin Lan wrote:
From: Mikulas Patocka mpatocka@redhat.com
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 Signed-off-by: Bin Lan bin.lan.cn@windriver.com
arch/parisc/Kconfig | 1 + arch/parisc/include/asm/cache.h | 11 ++++++++++- 2 files changed, 11 insertions(+), 1 deletion(-)
You seem to have forgotten to add the git id :(
Thank you. I will send v2 patch for review.
Bin Lan
linux-stable-mirror@lists.linaro.org
-
Bin Lan -
Greg KH