[PATCH v2 11/12] ARCv2: mm: THP: Implement flush_pmd_tlb_range() optimization

[Vineet Gupta <Vineet.Gupta1@synopsys.com>]

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>
---
 arch/arc/include/asm/hugepage.h |  4 ++++
 arch/arc/mm/tlb.c               | 20 ++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/arch/arc/include/asm/hugepage.h b/arch/arc/include/asm/hugepage.h
index d7614d2af454..bf74f507e038 100644
--- a/arch/arc/include/asm/hugepage.h
+++ b/arch/arc/include/asm/hugepage.h
@@ -75,4 +75,8 @@ extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
 #define __HAVE_ARCH_PGTABLE_WITHDRAW
 extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
 
+#define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
+extern void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,
+				unsigned long end);
+
 #endif
diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c
index 80e28555a5de..b28731c175b1 100644
--- a/arch/arc/mm/tlb.c
+++ b/arch/arc/mm/tlb.c
@@ -626,6 +626,26 @@ 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
-- 
1.9.1

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>