From 8840e14cd82d398d348b2947fad3a630e93260ba Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Tue, 13 Oct 2015 12:11:38 +0530 Subject: [PATCH] ARC: mm: Improve Duplicate PD Fault handler - Move the verbosity knob from .data to .bss by using inverted logic - No need to readout PD1 descriptor - clip the non pfn bits of PD0 to avoid clipping inside the loop Signed-off-by: Vineet Gupta --- arch/arc/mm/tlb.c | 48 +++++++++++++++++++++++------------------------ 1 file changed, 24 insertions(+), 24 deletions(-) diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c index 2a30c91f7977..5dcae21dd8dc 100644 --- a/arch/arc/mm/tlb.c +++ b/arch/arc/mm/tlb.c @@ -856,15 +856,15 @@ void arc_mmu_init(void) * the duplicate one. * -Knob to be verbose abt it.(TODO: hook them up to debugfs) */ -volatile int dup_pd_verbose = 1;/* Be slient abt it or complain (default) */ +volatile int dup_pd_silent; /* Be slient abt it or complain (default) */ void do_tlb_overlap_fault(unsigned long cause, unsigned long address, struct pt_regs *regs) { - int set, way, n; - unsigned long flags, is_valid; struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu; - unsigned int pd0[mmu->ways], pd1[mmu->ways]; + unsigned int pd0[mmu->ways]; + unsigned long flags; + int set; local_irq_save(flags); @@ -874,14 +874,16 @@ void do_tlb_overlap_fault(unsigned long cause, unsigned long address, /* loop thru all sets of TLB */ for (set = 0; set < mmu->sets; set++) { + int is_valid, way; + /* read out all the ways of current set */ for (way = 0, is_valid = 0; way < mmu->ways; way++) { write_aux_reg(ARC_REG_TLBINDEX, SET_WAY_TO_IDX(mmu, set, way)); write_aux_reg(ARC_REG_TLBCOMMAND, TLBRead); pd0[way] = read_aux_reg(ARC_REG_TLBPD0); - pd1[way] = read_aux_reg(ARC_REG_TLBPD1); is_valid |= pd0[way] & _PAGE_PRESENT; + pd0[way] &= PAGE_MASK; } /* If all the WAYS in SET are empty, skip to next SET */ @@ -890,30 +892,28 @@ void do_tlb_overlap_fault(unsigned long cause, unsigned long address, /* Scan the set for duplicate ways: needs a nested loop */ for (way = 0; way < mmu->ways - 1; way++) { + + int n; + if (!pd0[way]) continue; for (n = way + 1; n < mmu->ways; n++) { - if ((pd0[way] & PAGE_MASK) == - (pd0[n] & PAGE_MASK)) { - - if (dup_pd_verbose) { - pr_info("Duplicate PD's @" - "[%d:%d]/[%d:%d]\n", - set, way, set, n); - pr_info("TLBPD0[%u]: %08x\n", - way, pd0[way]); - } - - /* - * clear entry @way and not @n. This is - * critical to our optimised loop - */ - pd0[way] = pd1[way] = 0; - write_aux_reg(ARC_REG_TLBINDEX, + if (pd0[way] != pd0[n]) + continue; + + if (!dup_pd_silent) + pr_info("Dup TLB PD0 %08x @ set %d ways %d,%d\n", + pd0[way], set, way, n); + + /* + * clear entry @way and not @n. + * This is critical to our optimised loop + */ + pd0[way] = 0; + write_aux_reg(ARC_REG_TLBINDEX, SET_WAY_TO_IDX(mmu, set, way)); - __tlb_entry_erase(); - } + __tlb_entry_erase(); } } } -- 2.34.1