[2/4] riscv: Improve flush_tlb_range() for hugetlb pages

Message ID 20230711075434.10936-3-alexghiti@rivosinc.com
State New
Headers
Series riscv: tlb flush improvements |

Commit Message

Alexandre Ghiti July 11, 2023, 7:54 a.m. UTC
  flush_tlb_range() uses a fixed stride of PAGE_SIZE and in its current form,
when a hugetlb mapping needs to be flushed, flush_tlb_range() flushes the
whole tlb: so set a stride of the size of the hugetlb mapping in order to
only flush the hugetlb mapping.

Note that THPs are directly handled by flush_pmd_tlb_range().

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
 arch/riscv/mm/tlbflush.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
  

Patch

diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c
index fa03289853d8..3e4acef1f6bc 100644
--- a/arch/riscv/mm/tlbflush.c
+++ b/arch/riscv/mm/tlbflush.c
@@ -3,6 +3,7 @@ 
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/sched.h>
+#include <linux/hugetlb.h>
 #include <asm/sbi.h>
 #include <asm/mmu_context.h>
 
@@ -147,7 +148,14 @@  void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 		     unsigned long end)
 {
-	__flush_tlb_range(vma->vm_mm, start, end - start, PAGE_SIZE);
+	unsigned long stride_shift;
+
+	stride_shift = is_vm_hugetlb_page(vma) ?
+				huge_page_shift(hstate_vma(vma)) :
+				PAGE_SHIFT;
+
+	__flush_tlb_range(vma->vm_mm,
+			  start, end - start, 1 << stride_shift);
 }
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,