ARCv2: mm: THP: Implement flush_pmd_tlb_range() optimization

Implement the TLB flush routine to evict a sepcific Super TLB entry,
vs. moving to a new ASID on every such flush.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c
index 91905b1c3d72..005090e425f4 100644
--- a/arch/arc/mm/tlb.c
+++ b/arch/arc/mm/tlb.c
@@ -659,6 +659,26 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
         return pgtable;
 }
 
+void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,
+                         unsigned long end)
+{
+        unsigned int cpu;
+        unsigned long flags;
+
+        local_irq_save(flags);
+
+        cpu = smp_processor_id();
+
+        if (likely(asid_mm(vma->vm_mm, cpu) != MM_CTXT_NO_ASID)) {
+                unsigned int asid = hw_pid(vma->vm_mm, cpu);
+
+                /* No need to loop here: this will always be for 1 Huge Page */
+                tlb_entry_erase(start | _PAGE_HW_SZ | asid);
+        }
+
+        local_irq_restore(flags);
+}
+
 #endif
 
 /* Read the Cache Build Confuration Registers, Decode them and save into