On Friday 12 August 2011 01:54 PM, Lukasz Majewski wrote:
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 Majewskil.majewski@samsung.com Signed-off-by: Kyungmin Parkkyungmin.park@samsung.com CC: Aneesh Vaneesh@ti.com CC: Albert ARIBAUDalbert.u.boot@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;
+}
Does memalign() take 0 as input and if so what is the output. The GNU C library seems to mandate only that it's a power of 2. But the following man page seems to says that "The value of alignment must be a power of two and must be greater than or equal to the size of a word."
http://www.s-gms.ms.edus.si/cgi-bin/man-cgi?memalign+3C
Also, you seem to be using get_dcache_line_size() in MMC driver. Is this function defined for all platforms. Maybe, you must implement a weakly linked default function for all platforms?
best regards, Aneesh