From: Ralf Baechle Date: Sat, 9 Jun 2012 19:48:47 +0000 (+0100) Subject: MIPS: Fix potencial corruption X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a16dad77634;p=linux-beck.git MIPS: Fix potencial corruption Normally r4k_dma_cache_inv should only ever be called with cacheline aligned addresses. If however, it isn't there is the theoretical possibility of data corruption. There is no correct way of handling this and anyway, it should only happen if the DMA API is used incorrectly so drop There is a different corruption scenario with these CACHE instructions removed but again there is no way of handling this correctly and it can be triggered only through incorrect use of the DMA API. So just get rid of the complexity. Signed-off-by: Ralf Baechle Reported-by: James Rodriguez --- diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c index 4c32ede464b5..2b6146241bde 100644 --- a/arch/mips/mm/c-r4k.c +++ b/arch/mips/mm/c-r4k.c @@ -632,9 +632,6 @@ static void r4k_dma_cache_inv(unsigned long addr, unsigned long size) if (size >= scache_size) r4k_blast_scache(); else { - unsigned long lsize = cpu_scache_line_size(); - unsigned long almask = ~(lsize - 1); - /* * There is no clearly documented alignment requirement * for the cache instruction on MIPS processors and @@ -643,9 +640,6 @@ static void r4k_dma_cache_inv(unsigned long addr, unsigned long size) * hit ops with insufficient alignment. Solved by * aligning the address to cache line size. */ - cache_op(Hit_Writeback_Inv_SD, addr & almask); - cache_op(Hit_Writeback_Inv_SD, - (addr + size - 1) & almask); blast_inv_scache_range(addr, addr + size); } __sync(); @@ -655,12 +649,7 @@ static void r4k_dma_cache_inv(unsigned long addr, unsigned long size) if (cpu_has_safe_index_cacheops && size >= dcache_size) { r4k_blast_dcache(); } else { - unsigned long lsize = cpu_dcache_line_size(); - unsigned long almask = ~(lsize - 1); - R4600_HIT_CACHEOP_WAR_IMPL; - cache_op(Hit_Writeback_Inv_D, addr & almask); - cache_op(Hit_Writeback_Inv_D, (addr + size - 1) & almask); blast_inv_dcache_range(addr, addr + size); }