[U-Boot] [PATCH] armv7:cache: D cache line size read method

[Lukasz Majewski]

This commit adds support for reading the D cache line size for armv7
architecture.

The get_dcache_line_size() function is supposed to work in conjunction
with memalign call to provide D cache aligned DMA buffers.

Signed-off-by: Lukasz Majewski <l.majewski at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
CC: Aneesh V <aneesh at ti.com>
CC: Albert ARIBAUD <albert.u.boot at aribaud.net>
---
 arch/arm/cpu/armv7/cache_v7.c |   25 +++++++++++++++++++++++++
 include/common.h              |    1 +
 2 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/arch/arm/cpu/armv7/cache_v7.c b/arch/arm/cpu/armv7/cache_v7.c
index 3e1e1bf..bd0b1a8 100644
--- a/arch/arm/cpu/armv7/cache_v7.c
+++ b/arch/arm/cpu/armv7/cache_v7.c
@@ -246,6 +246,21 @@ static void v7_inval_tlb(void)
 	CP15ISB;
 }
 
+/* Read the cache line size (bytes) */
+static int v7_dcache_line_size(void)
+{
+	u32 ccsidr, log2_line_len;
+
+	ccsidr = get_ccsidr();
+
+	log2_line_len = ((ccsidr & CCSIDR_LINE_SIZE_MASK) >>
+				CCSIDR_LINE_SIZE_OFFSET) + 2;
+	/* Converting from words to bytes */
+	log2_line_len += 2;
+
+	return 1 << log2_line_len;
+}
+
 void invalidate_dcache_all(void)
 {
 	v7_maint_dcache_all(ARMV7_DCACHE_INVAL_ALL);
@@ -303,6 +318,11 @@ void  flush_cache(unsigned long start, unsigned long size)
 {
 	flush_dcache_range(start, start + size);
 }
+
+int get_dcache_line_size(void)
+{
+	return v7_dcache_line_size();
+}
 #else /* #ifndef CONFIG_SYS_DCACHE_OFF */
 void invalidate_dcache_all(void)
 {
@@ -327,6 +347,11 @@ void arm_init_before_mmu(void)
 void  flush_cache(unsigned long start, unsigned long size)
 {
 }
+
+int get_dcache_line_size(void)
+{
+	return 0;
+}
 #endif /* #ifndef CONFIG_SYS_DCACHE_OFF */
 
 #ifndef CONFIG_SYS_ICACHE_OFF
diff --git a/include/common.h b/include/common.h
index 12a1074..b535300 100644
--- a/include/common.h
+++ b/include/common.h
@@ -622,6 +622,7 @@ void	flush_dcache_range(unsigned long start, unsigned long stop);
 void	invalidate_dcache_range(unsigned long start, unsigned long stop);
 void	invalidate_dcache_all(void);
 void	invalidate_icache_all(void);
+int     get_dcache_line_size(void);
 
 /* arch/$(ARCH)/lib/ticks.S */
 unsigned long long get_ticks(void);
-- 
1.7.2.3