[RFC PATCH v4 5/6] arm64: tlb: Use translation level hint in vm_flags

[Zhenyu Ye <yezhenyu2@xxxxxxxxxx>]

This patch used the VM_LEVEL flags in vma->vm_flags to set the
TTL field in tlbi instruction.

Signed-off-by: Zhenyu Ye <yezhenyu2@xxxxxxxxxx>
---
 arch/arm64/include/asm/mmu.h      |  2 ++
 arch/arm64/include/asm/tlbflush.h | 14 ++++++++------
 arch/arm64/mm/mmu.c               | 14 ++++++++++++++
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index d79ce6df9e12..a8b8824a7405 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -86,6 +86,8 @@ extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
 extern void *fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot);
 extern void mark_linear_text_alias_ro(void);
 extern bool kaslr_requires_kpti(void);
+extern unsigned int get_vma_level(struct vm_area_struct *vma);
+
 
 #define INIT_MM_CONTEXT(name)	\
 	.pgd = init_pg_dir,
diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index d141c080e494..93bb09fdfafd 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -218,10 +218,11 @@ static inline void flush_tlb_page_nosync(struct vm_area_struct *vma,
 					 unsigned long uaddr)
 {
 	unsigned long addr = __TLBI_VADDR(uaddr, ASID(vma->vm_mm));
+	unsigned int level = get_vma_level(vma);
 
 	dsb(ishst);
-	__tlbi_level(vale1is, addr, 0);
-	__tlbi_user_level(vale1is, addr, 0);
+	__tlbi_level(vale1is, addr, level);
+	__tlbi_user_level(vale1is, addr, level);
 }
 
 static inline void flush_tlb_page(struct vm_area_struct *vma,
@@ -242,6 +243,7 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
 				     unsigned long stride, bool last_level)
 {
 	unsigned long asid = ASID(vma->vm_mm);
+	unsigned int level = get_vma_level(vma);
 	unsigned long addr;
 
 	start = round_down(start, stride);
@@ -261,11 +263,11 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
 	dsb(ishst);
 	for (addr = start; addr < end; addr += stride) {
 		if (last_level) {
-			__tlbi_level(vale1is, addr, 0);
-			__tlbi_user_level(vale1is, addr, 0);
+			__tlbi_level(vale1is, addr, level);
+			__tlbi_user_level(vale1is, addr, level);
 		} else {
-			__tlbi_level(vae1is, addr, 0);
-			__tlbi_user_level(vae1is, addr, 0);
+			__tlbi_level(vae1is, addr, level);
+			__tlbi_user_level(vae1is, addr, level);
 		}
 	}
 	dsb(ish);
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 128f70852bf3..e6a1221cd86b 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -60,6 +60,20 @@ static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused;
 
 static DEFINE_SPINLOCK(swapper_pgdir_lock);
 
+inline unsigned int get_vma_level(struct vm_area_struct *vma)
+{
+	unsigned int level = 0;
+	if (vma->vm_flags & VM_LEVEL_PUD)
+		level = 1;
+	else if (vma->vm_flags & VM_LEVEL_PMD)
+		level = 2;
+	else if (vma->vm_flags & VM_LEVEL_PTE)
+		level = 3;
+
+	vma->vm_flags &= ~(VM_LEVEL_PUD | VM_LEVEL_PMD | VM_LEVEL_PTE);
+	return level;
+}
+
 void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd)
 {
 	pgd_t *fixmap_pgdp;
-- 
2.19.1