[U-Boot] [PATCH v1 7/9] MIPS: kconfig: add option for MIPS_L1_CACHE_SHIFT

[Daniel Schwierzeck]

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 at gmail.com>

---

 arch/mips/Kconfig             | 21 +++++++++++++++++++++
 arch/mips/include/asm/cache.h | 14 ++++----------
 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 388e4c0..1b39c4c 100644
--- 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
--- 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__ */
-- 
2.5.0