arm64: cacheinfo: Update cache_line_size detected from DT or PPTT
cache_line_size is derived from CTR_EL0.CWG field and is called mostly
for I/O device drivers. For some platforms like the HiSilicon Kunpeng920
server SoC, cache line sizes are different between L1/2 cache and L3
cache while L1 cache line size is 64-byte and L3 is 128-byte, but
CTR_EL0.CWG is misreporting using L1 cache line size.
We shall correct the right value which is important for I/O performance.
Let's update the cache line size if it is detected from DT or PPTT
information.
Cc: Will Deacon <will.deacon@arm.com>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Zhenfa Qiu <qiuzhenfa@hisilicon.com>
Reported-by: Zhenfa Qiu <qiuzhenfa@hisilicon.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c
index 0bf0a83..0c0cd4d 100644
--- a/arch/arm64/kernel/cacheinfo.c
+++ b/arch/arm64/kernel/cacheinfo.c
@@ -28,6 +28,17 @@
#define CLIDR_CTYPE(clidr, level) \
(((clidr) & CLIDR_CTYPE_MASK(level)) >> CLIDR_CTYPE_SHIFT(level))
+int cache_line_size(void)
+{
+ u32 cwg = cache_type_cwg();
+
+ if (coherency_max_size != 0)
+ return coherency_max_size;
+
+ return cwg ? 4 << cwg : ARCH_DMA_MINALIGN;
+}
+EXPORT_SYMBOL_GPL(cache_line_size);
+
static inline enum cache_type get_cache_type(int level)
{
u64 clidr;
