On Tue, May 26, 2015 at 11:25:08PM -0700, Petri Gynther wrote:
> bmips_wr_vec() copies exception vector code from start to dst.
>
> The call to dma_cache_wback() needs to flush (end-start) bytes,
> starting at dst, from write-back cache to memory.
>
> Signed-off-by: Petri Gynther <pgynther@xxxxxxxxxx>
> ---
> arch/mips/kernel/smp-bmips.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
> index fd528d7..336708a 100644
> --- a/arch/mips/kernel/smp-bmips.c
> +++ b/arch/mips/kernel/smp-bmips.c
> @@ -444,7 +444,7 @@ struct plat_smp_ops bmips5000_smp_ops = {
> static void bmips_wr_vec(unsigned long dst, char *start, char *end)
> {
> memcpy((void *)dst, start, end - start);
> - dma_cache_wback((unsigned long)start, end - start);
> + dma_cache_wback(dst, end - start);
dma_cache_wback is a guess what - DMA function. It doesn't handle
I-caches at all and on some platforms might actually do nothing at all.
or use other optimizations that only work for DMA buffers and it's not
SMP aware - nor will it. So if it ever worked for your case then just
because you're lucky. This really should use flush_icache_range which
also conveniently for your code takes an end pointer as argument.
Ralf
