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Subject[PATCH V2] arm64: tlbflush: avoid writing RES0 bits
Date
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 <pelcan@codeaurora.org>
---
arch/arm64/include/asm/tlbflush.h | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index 9e82dd7..b1205e9 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -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);
@@ -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);
--
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.
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