[RFC PATCH v1 2/3] arm64: tlb: use mm_struct.context.flags to indicate TTL

[Zhenyu Ye <yezhenyu2@xxxxxxxxxx>]

Use Architecture-specific MM context to indicate the level of page
table walk. This avoids lots of changes to common-interface.

Signed-off-by: Zhenyu Ye <yezhenyu2@xxxxxxxxxx>
---
 arch/arm64/include/asm/mmu.h      | 11 +++++++++++
 arch/arm64/include/asm/tlbflush.h |  8 +++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index e4d862420bb4..7410d2997c2a 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -8,6 +8,10 @@
 #include <asm/cputype.h>
 
 #define MMCF_AARCH32	0x1	/* mm context flag for AArch32 executables */
+#define TLBI_LEVEL_1	0x10	/* mm context flag for the level of ptw */
+#define TLBI_LEVEL_2	0x20
+#define TLBI_LEVEL_3	0x30
+
 #define USER_ASID_BIT	48
 #define USER_ASID_FLAG	(UL(1) << USER_ASID_BIT)
 #define TTBR_ASID_MASK	(UL(0xffff) << 48)
@@ -19,6 +23,10 @@
 typedef struct {
 	atomic64_t	id;
 	void		*vdso;
+	/*
+	 * flags[3:0]: AArch32 executables
+	 * flags[7:4]: the level of page table walk
+	 */
 	unsigned long	flags;
 } mm_context_t;
 
@@ -29,6 +37,9 @@ typedef struct {
  */
 #define ASID(mm)	((mm)->context.id.counter & 0xffff)
 
+/* This macro is only used by TLBI TTL */
+#define TLBI_LEVEL(mm)	((mm)->context.flags >> 4 & 0xf)
+
 extern bool arm64_use_ng_mappings;
 
 static inline bool arm64_kernel_unmapped_at_el0(void)
diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index 10b12710b7cc..9f02a5383ac3 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -172,7 +172,8 @@ static inline void flush_tlb_mm(struct mm_struct *mm)
 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), 0);
+	unsigned long ttl = (__TLB_TG << 2) + TLBI_LEVEL(vma->vm_mm);
+	unsigned long addr = __TLBI_VADDR(uaddr, ASID(vma->vm_mm), ttl);
 
 	dsb(ishst);
 	__tlbi(vale1is, addr);
@@ -197,6 +198,7 @@ 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 long ttl = (__TLB_TG << 2) + TLBI_LEVEL(vma->vm_mm);
 	unsigned long addr;
 
 	start = round_down(start, stride);
@@ -210,8 +212,8 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
 	/* Convert the stride into units of 4k */
 	stride >>= 12;
 
-	start = __TLBI_VADDR(start, asid, 0);
-	end = __TLBI_VADDR(end, asid, 0);
+	start = __TLBI_VADDR(start, asid, ttl);
+	end = __TLBI_VADDR(end, asid, ttl);
 
 	dsb(ishst);
 	for (addr = start; addr < end; addr += stride) {
-- 
2.19.1