[PATCH v1 03/13] arm64: mm: Implicitly invalidate user ASID based on TLBI operation

[Ryan Roberts <ryan.roberts@arm.com>]

When kpti is enabled, separate ASIDs are used for userspace and
kernelspace, requiring ASID-qualified TLB invalidation by virtual
address to invalidate both of them.

Push the logic for invalidating the two ASIDs down into the low-level
tlbi-op-specific functions and remove the burden from the caller to
handle the kpti-specific behaviour.

Co-developed-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
 arch/arm64/include/asm/tlbflush.h | 27 ++++++++++-----------------
 1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index c5111d2afc66..31f43d953ce2 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -110,6 +110,7 @@ typedef void (*tlbi_op)(u64 arg);
 static __always_inline void vae1is(u64 arg)
 {
 	__tlbi(vae1is, arg);
+	__tlbi_user(vae1is, arg);
 }
 
 static __always_inline void vae2is(u64 arg)
@@ -126,6 +127,7 @@ static __always_inline void vale1(u64 arg)
 static __always_inline void vale1is(u64 arg)
 {
 	__tlbi(vale1is, arg);
+	__tlbi_user(vale1is, arg);
 }
 
 static __always_inline void vale2is(u64 arg)
@@ -162,11 +164,6 @@ static __always_inline void __tlbi_level(tlbi_op op, u64 addr, u32 level)
 	op(arg);
 }
 
-#define __tlbi_user_level(op, arg, level) do {				\
-	if (arm64_kernel_unmapped_at_el0())				\
-		__tlbi_level(op, (arg | USER_ASID_FLAG), level);	\
-} while (0)
-
 /*
  * This macro creates a properly formatted VA operand for the TLB RANGE. The
  * value bit assignments are:
@@ -435,8 +432,6 @@ static inline void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
  * @stride:	Flush granularity
  * @asid:	The ASID of the task (0 for IPA instructions)
  * @tlb_level:	Translation Table level hint, if known
- * @tlbi_user:	If 'true', call an additional __tlbi_user()
- *              (typically for user ASIDs). 'flase' for IPA instructions
  * @lpa2:	If 'true', the lpa2 scheme is used as set out below
  *
  * When the CPU does not support TLB range operations, flush the TLB
@@ -462,6 +457,7 @@ static inline void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
 static __always_inline void rvae1is(u64 arg)
 {
 	__tlbi(rvae1is, arg);
+	__tlbi_user(rvae1is, arg);
 }
 
 static __always_inline void rvale1(u64 arg)
@@ -473,6 +469,7 @@ static __always_inline void rvale1(u64 arg)
 static __always_inline void rvale1is(u64 arg)
 {
 	__tlbi(rvale1is, arg);
+	__tlbi_user(rvale1is, arg);
 }
 
 static __always_inline void rvaale1is(u64 arg)
@@ -491,7 +488,7 @@ static __always_inline void __tlbi_range(tlbi_op op, u64 arg)
 }
 
 #define __flush_tlb_range_op(op, start, pages, stride,			\
-				asid, tlb_level, tlbi_user, lpa2)	\
+				asid, tlb_level, lpa2)			\
 do {									\
 	typeof(start) __flush_start = start;				\
 	typeof(pages) __flush_pages = pages;				\
@@ -506,8 +503,6 @@ do {									\
 		    (lpa2 && __flush_start != ALIGN(__flush_start, SZ_64K))) {	\
 			addr = __TLBI_VADDR(__flush_start, asid);	\
 			__tlbi_level(op, addr, tlb_level);		\
-			if (tlbi_user)					\
-				__tlbi_user_level(op, addr, tlb_level);	\
 			__flush_start += stride;			\
 			__flush_pages -= stride >> PAGE_SHIFT;		\
 			continue;					\
@@ -518,8 +513,6 @@ do {									\
 			addr = __TLBI_VADDR_RANGE(__flush_start >> shift, asid, \
 						scale, num, tlb_level);	\
 			__tlbi_range(r##op, addr);			\
-			if (tlbi_user)					\
-				__tlbi_user(r##op, addr);		\
 			__flush_start += __TLBI_RANGE_PAGES(num, scale) << PAGE_SHIFT; \
 			__flush_pages -= __TLBI_RANGE_PAGES(num, scale);\
 		}							\
@@ -528,7 +521,7 @@ do {									\
 } while (0)
 
 #define __flush_s2_tlb_range_op(op, start, pages, stride, tlb_level) \
-	__flush_tlb_range_op(op, start, pages, stride, 0, tlb_level, false, kvm_lpa2_is_enabled());
+	__flush_tlb_range_op(op, start, pages, stride, 0, tlb_level, kvm_lpa2_is_enabled());
 
 static inline bool __flush_tlb_range_limit_excess(unsigned long start,
 		unsigned long end, unsigned long pages, unsigned long stride)
@@ -568,10 +561,10 @@ static inline void __flush_tlb_range_nosync(struct mm_struct *mm,
 
 	if (last_level)
 		__flush_tlb_range_op(vale1is, start, pages, stride, asid,
-				     tlb_level, true, lpa2_is_enabled());
+				     tlb_level, lpa2_is_enabled());
 	else
 		__flush_tlb_range_op(vae1is, start, pages, stride, asid,
-				     tlb_level, true, lpa2_is_enabled());
+				     tlb_level, lpa2_is_enabled());
 
 	mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
 }
@@ -630,7 +623,7 @@ static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end
 
 	dsb(ishst);
 	__flush_tlb_range_op(vaale1is, start, pages, stride, 0,
-			     TLBI_TTL_UNKNOWN, false, lpa2_is_enabled());
+			     TLBI_TTL_UNKNOWN, lpa2_is_enabled());
 	dsb(ish);
 	isb();
 }
@@ -681,6 +674,6 @@ static inline bool huge_pmd_needs_flush(pmd_t oldpmd, pmd_t newpmd)
 }
 #define huge_pmd_needs_flush huge_pmd_needs_flush
 
+#undef __tlbi_user
 #endif
-
 #endif
-- 
2.43.0