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 Xu<hong...@atmel.com> >> Tested-by: Elen Song<elen.s...@atmel.com> >> CC: Albert Aribaud<albert.u.b...@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? ;-) BR, Eric > best regards, > Aneesh _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot