MIPS: kconfig: add option for MIPS_L1_CACHE_SHIFT

Add Kconfig symbol for L1 cache shift like the kernel does.
The value of CONFIG_SYS_CACHELINE_SIZE is not a reliable source
for ARCH_DMA_MINALIGN anymore, because it is optional on MIPS.
If CONFIG_SYS_CACHELINE_SIZE is not defined by a board, the
cache sizes are automatically detected and ARCH_DMA_MINALIGN
would be set to 128 Bytes.

The default value for CONFIG_MIPS_L1_CACHE_SHIFT is 5 which
corresponds to 32 Bytes. All current MIPS boards already used
that value. While on it, fix the Malta board to use a value of 6
like the kernel port does.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 388e4c0..1b39c4c 100644 (file)
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -28,6 +28,7 @@ config TARGET_MALTA
        select SUPPORTS_CPU_MIPS32_R1
        select SUPPORTS_CPU_MIPS32_R2
        select SWAP_IO_SPACE
+       select MIPS_L1_CACHE_SHIFT_6
 
 config TARGET_VCT
        bool "Support vct"
@@ -196,6 +197,26 @@ config SWAP_IO_SPACE
 config SYS_MIPS_CACHE_INIT_RAM_LOAD
        bool
 
+config MIPS_L1_CACHE_SHIFT_4
+       bool
+
+config MIPS_L1_CACHE_SHIFT_5
+       bool
+
+config MIPS_L1_CACHE_SHIFT_6
+       bool
+
+config MIPS_L1_CACHE_SHIFT_7
+       bool
+
+config MIPS_L1_CACHE_SHIFT
+       int
+       default "7" if MIPS_L1_CACHE_SHIFT_7
+       default "6" if MIPS_L1_CACHE_SHIFT_6
+       default "5" if MIPS_L1_CACHE_SHIFT_5
+       default "4" if MIPS_L1_CACHE_SHIFT_4
+       default "5"
+
 endif
 
 endmenu

diff --git a/arch/mips/include/asm/cache.h b/arch/mips/include/asm/cache.h
index 0dfb54e..806bd26 100644 (file)
--- a/arch/mips/include/asm/cache.h
+++ b/arch/mips/include/asm/cache.h
@@ -7,15 +7,9 @@
 #ifndef __MIPS_CACHE_H__
 #define __MIPS_CACHE_H__
 
-/*
- * The maximum L1 data cache line size on MIPS seems to be 128 bytes.  We use
- * that as a default for aligning DMA buffers unless the board config has
- * specified another cache line size.
- */
-#ifdef CONFIG_SYS_CACHELINE_SIZE
-#define ARCH_DMA_MINALIGN      CONFIG_SYS_CACHELINE_SIZE
-#else
-#define ARCH_DMA_MINALIGN      128
-#endif
+#define L1_CACHE_SHIFT         CONFIG_MIPS_L1_CACHE_SHIFT
+#define L1_CACHE_BYTES         (1 << L1_CACHE_SHIFT)
+
+#define ARCH_DMA_MINALIGN      (L1_CACHE_BYTES)
 
 #endif /* __MIPS_CACHE_H__ */