Hi Eric,
On Mon, Aug 22, 2011 at 7:44 AM, Hong Xu hong.xu@atmel.com wrote:
Hi Aneesh,
On 08/19/2011 10:20 PM, Aneesh V wrote:
Hi Hong,
On Friday 19 August 2011 02:53 PM, Hong Xu wrote:
Add a new file arch/arm/cpu/arm926ejs/cache.c and put cache operations into this file.
Signed-off-by: Hong Xuhong.xu@atmel.com Tested-by: Elen Songelen.song@atmel.com CC: Albert Aribaudalbert.u.boot@aribaud.net
Since V1 Modified copyright line Fix for compiling warnings Changed the way to use CONFIG_SYS_CACHELINE_SIZE When unaligned buffer detected, emit ERROR instead of WARNING
Do not make a common v5,v6 cache file. It seems arm946 is lack of Test-and-Clean DCache operation. And maybe more differents...
arch/arm/cpu/arm926ejs/Makefile | 2 +- arch/arm/cpu/arm926ejs/cache.c | 135 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 136 insertions(+), 1 deletions(-) create mode 100644 arch/arm/cpu/arm926ejs/cache.c
[...]
+/*
- The buffer range to be flushed is [start, stop)
- */
+void flush_dcache_range(unsigned long start, unsigned long stop) +{
- cache_range_op(start, stop, FLUSH_CACHE_OP);
+}
+void flush_dcache_all(void) +{
- /*
- * ARM926EJ-S Technical Reference Manual, Chap 2.3.8
- * Clean& Invalidate the entire DCache
- */
- asm("0: mrc p15, 0, r15, c7, c14, 3\n\t" "bne 0b\n" : : :
"memory");
- /* Drain WB */
- asm("mcr p15, 0, %0, c7, c10, 4\n" : : "r" (0));
While looking at the manuals for the armv5 compatibility I stumbled upon the following in Chapter 2.3.8. Are you sure your flush_dcache_all implementation is correct? I suspect the above is flushing only one line?
"The test, clean, and invalidate DCache instruction is the same as test and clean DCache, except that when the entire cache has been cleaned, it is invalidated. This means that you can use the following loop to clean and invalidate the entire DCache:
tci_loop: MRC p15, 0, r15, c7, c14, 3 BNE tci_loop "
As stated in the manual, we can use a loop to clean and invalidate the entire DCache.
The "asm" statement above is a loop, isn't it? ;-)
Oops! I didn't notice that. Sorry for the noise. But, maybe, it could be made two separate lines to make it more readable.
br, Aneesh