ARC: Fix bogus gcc warning and micro-optimise TLB iteration loop

------------------>8----------------------
arch/arc/mm/tlb.c: In function ‘do_tlb_overlap_fault’:
arch/arc/mm/tlb.c:688:13: warning: array subscript is above array bounds
[-Warray-bounds]
         (pd0[n] & PAGE_MASK)) {
             ^
------------------>8----------------------

While at it, remove the usless last iteration of outer loop when reading
a TLB SET for duplicate entries.

Suggested-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c
index 71cb26d..5f53050 100644 (file)
--- a/arch/arc/mm/tlb.c
+++ b/arch/arc/mm/tlb.c
@@ -610,9 +610,9 @@ void do_tlb_overlap_fault(unsigned long cause, unsigned long address,
                          struct pt_regs *regs)
 {
        int set, way, n;
-       unsigned int pd0[4], pd1[4];    /* assume max 4 ways */
        unsigned long flags, is_valid;
        struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
+       unsigned int pd0[mmu->ways], pd1[mmu->ways];
 
        local_irq_save(flags);
 
@@ -637,7 +637,7 @@ void do_tlb_overlap_fault(unsigned long cause, unsigned long address,
                        continue;
 
                /* Scan the set for duplicate ways: needs a nested loop */
-               for (way = 0; way < mmu->ways; way++) {
+               for (way = 0; way < mmu->ways - 1; way++) {
                        if (!pd0[way])
                                continue;