On Mon, Aug 04, 2014 at 11:08:50AM +0100, James Hogan wrote: > Hi Aurelien, > > On 02/08/14 22:35, Aurelien Jarno wrote: > > On Thu, Jul 31, 2014 at 10:33:55AM -0700, David Daney wrote: > >> diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c > >> index f99ec587..341add1 100644 > >> --- a/arch/mips/mm/tlbex.c > >> +++ b/arch/mips/mm/tlbex.c > >> @@ -1299,6 +1299,8 @@ static void build_r4000_tlb_refill_handler(void) > >> } > >> #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT > >> uasm_l_tlb_huge_update(&l, p); > >> + if (!use_bbit_insns()) > >> + UASM_i_LW(&p, K0, 0, K1); > >> build_huge_update_entries(&p, htlb_info.huge_pte, K1); > >> build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random, > >> htlb_info.restore_scratch); > > > > This patch fixes the issue, thanks. That said it doesn't look fully > > correct. The test should be done the same way as for > > build_fast_tlb_refill_handler. For example the fast handler is not > > called on a 32-bit machine with bbit instructions, so it would need > > to reload K0. > > In the non fast case build_is_huge_pte() will still use bbit1 if > available after restoring K0, and I don't think the bbit1 would clobber > K0 when the branch is taken, so I think the test for !use_bbit_insns() > is correct. > Oh you are right! Therefore this second patch is: Reviewed-by: Aurelien Jarno <aurelien@xxxxxxxxxxx> Tested-by: Aurelien Jarno <aurelien@xxxxxxxxxxx> -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurelien@xxxxxxxxxxx http://www.aurel32.net
