arm64: tlbflush: avoid writing RES0 bits

PATCH In review Philip Elcan 2 participants 2 messages Mar 28, 2018 arm64

Share & tools

Philip Elcan

author

2018-03-28 01:55 UTC #0 lore raw

PATCH v3 1/1 arm64: tlbflush: avoid writing RES0 bits

Several of the bits of the TLBI register operand are RES0 per the ARM ARM, so TLBI operations should avoid writing non-zero values to these bits.

This patch adds a macro __TLBI_VADDR(addr, asid) that creates the operand register in the correct format and honors the RES0 bits.

Signed-off-by Philip Elcan <[email protected]>

---
 arch/arm64/include/asm/tlbflush.h | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

arch/arm64/include/asm/tlbflush.h +17 -8

index 9e82dd7..dfc61d7 100644
@@ -60,6 +60,15 @@
 		__tlbi(op, (arg) | USER_ASID_FLAG);				\
 } while (0)
 
+/* This macro creates a properly formatted VA operand for the TLBI */
+#define __TLBI_VADDR(addr, asid)				\
+	({							\
+		unsigned long __ta = (addr) >> 12;		\
+		__ta &= GENMASK_ULL(43, 0);			\
+		__ta |= (unsigned long)(asid) << 48;		\
+		__ta;						\
+	})
+
 /*
  *	TLB Management
  *	==============

@@ -117,7 +126,7 @@ static inline void flush_tlb_all(void)
 
 static inline void flush_tlb_mm(struct mm_struct *mm)
 {
-	unsigned long asid = ASID(mm) << 48;
+	unsigned long asid = __TLBI_VADDR(0, ASID(mm));
 
 	dsb(ishst);
 	__tlbi(aside1is, asid);

@@ -128,7 +137,7 @@ static inline void flush_tlb_mm(struct mm_struct *mm)
 static inline void flush_tlb_page(struct vm_area_struct *vma,
 				  unsigned long uaddr)
 {
-	unsigned long addr = uaddr >> 12 | (ASID(vma->vm_mm) << 48);
+	unsigned long addr = __TLBI_VADDR(uaddr, ASID(vma->vm_mm));
 
 	dsb(ishst);
 	__tlbi(vale1is, addr);

@@ -146,7 +155,7 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
 				     unsigned long start, unsigned long end,
 				     bool last_level)
 {
-	unsigned long asid = ASID(vma->vm_mm) << 48;
+	unsigned long asid = ASID(vma->vm_mm);
 	unsigned long addr;
 
 	if ((end - start) > MAX_TLB_RANGE) {

@@ -154,8 +163,8 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
 		return;
 	}
 
-	start = asid | (start >> 12);
-	end = asid | (end >> 12);
+	start = __TLBI_VADDR(start, asid);
+	end = __TLBI_VADDR(end, asid);
 
 	dsb(ishst);
 	for (addr = start; addr < end; addr += 1 << (PAGE_SHIFT - 12)) {

@@ -185,8 +194,8 @@ static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end
 		return;
 	}
 
-	start >>= 12;
-	end >>= 12;
+	start = __TLBI_VADDR(start, 0);
+	end = __TLBI_VADDR(end, 0);
 
 	dsb(ishst);
 	for (addr = start; addr < end; addr += 1 << (PAGE_SHIFT - 12))

@@ -202,7 +211,7 @@ static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end
 static inline void __flush_tlb_pgtable(struct mm_struct *mm,
 				       unsigned long uaddr)
 {
-	unsigned long addr = uaddr >> 12 | (ASID(mm) << 48);
+	unsigned long addr = __TLBI_VADDR(uaddr, ASID(mm));
 
 	__tlbi(vae1is, addr);
 	__tlbi_user(vae1is, addr);

Signature · 3 lines

Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.

Mark Rutland

reviewer Acked-by on v3 1/1

2018-03-28 10:19 UTC #1 lore raw

Quoted 18 lines · Philip Elcan

Several of the bits of the TLBI register operand are RES0 per the ARM ARM, so TLBI operations should avoid writing non-zero values to these bits.
This patch adds a macro __TLBI_VADDR(addr, asid) that creates the operand register in the correct format and honors the RES0 bits.
Signed-off-by Philip Elcan <[email protected]>
---
 arch/arm64/include/asm/tlbflush.h | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)
arch/arm64/include/asm/tlbflush.h +0 -0
index 9e82dd7..dfc61d7 100644
@@ -60,6 +60,15 @@
 		__tlbi(op, (arg) | USER_ASID_FLAG);				\

arch/arm64/include/asm/tlbflush.h line 70

Quoted 10 lines

arch/arm64/include/asm/tlbflush.h +8 -0

 } while (0)
 
+/* This macro creates a properly formatted VA operand for the TLBI */
+#define __TLBI_VADDR(addr, asid)				\
+	({							\
+		unsigned long __ta = (addr) >> 12;		\
+		__ta &= GENMASK_ULL(43, 0);			\
+		__ta |= (unsigned long)(asid) << 48;		\
+		__ta;						\
+	})

As a minor nit, we typically don't indent the start of the macro function body, and we could drop the leading tab on each line, but either way:

Acked-by Mark Rutland <[email protected]>

Thanks,
Mark.

Quoted 67 lines

arch/arm64/include/asm/tlbflush.h +9 -8

+
 /*
  *	TLB Management
  *	==============

@@ -117,7 +126,7 @@ static inline void flush_tlb_all(void)
 
 static inline void flush_tlb_mm(struct mm_struct *mm)
 {
-	unsigned long asid = ASID(mm) << 48;
+	unsigned long asid = __TLBI_VADDR(0, ASID(mm));
 
 	dsb(ishst);
 	__tlbi(aside1is, asid);

@@ -128,7 +137,7 @@ static inline void flush_tlb_mm(struct mm_struct *mm)
 static inline void flush_tlb_page(struct vm_area_struct *vma,
 				  unsigned long uaddr)
 {
-	unsigned long addr = uaddr >> 12 | (ASID(vma->vm_mm) << 48);
+	unsigned long addr = __TLBI_VADDR(uaddr, ASID(vma->vm_mm));
 
 	dsb(ishst);
 	__tlbi(vale1is, addr);

@@ -146,7 +155,7 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
 				     unsigned long start, unsigned long end,
 				     bool last_level)
 {
-	unsigned long asid = ASID(vma->vm_mm) << 48;
+	unsigned long asid = ASID(vma->vm_mm);
 	unsigned long addr;
 
 	if ((end - start) > MAX_TLB_RANGE) {

@@ -154,8 +163,8 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
 		return;
 	}
 
-	start = asid | (start >> 12);
-	end = asid | (end >> 12);
+	start = __TLBI_VADDR(start, asid);
+	end = __TLBI_VADDR(end, asid);
 
 	dsb(ishst);
 	for (addr = start; addr < end; addr += 1 << (PAGE_SHIFT - 12)) {

@@ -185,8 +194,8 @@ static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end
 		return;
 	}
 
-	start >>= 12;
-	end >>= 12;
+	start = __TLBI_VADDR(start, 0);
+	end = __TLBI_VADDR(end, 0);
 
 	dsb(ishst);
 	for (addr = start; addr < end; addr += 1 << (PAGE_SHIFT - 12))

@@ -202,7 +211,7 @@ static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end
 static inline void __flush_tlb_pgtable(struct mm_struct *mm,
 				       unsigned long uaddr)
 {
-	unsigned long addr = uaddr >> 12 | (ASID(mm) << 48);
+	unsigned long addr = __TLBI_VADDR(uaddr, ASID(mm));
 
 	__tlbi(vae1is, addr);
 	__tlbi_user(vae1is, addr);

Signature · 3 lines

Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.