* [PATCH V3] arm64: tlbflush: avoid writing RES0 bits
@ 2018-03-28 1:55 Philip Elcan
2018-03-28 10:19 ` Mark Rutland
0 siblings, 1 reply; 2+ messages in thread
From: Philip Elcan @ 2018-03-28 1:55 UTC (permalink / raw)
To: linux-arm-kernel
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 | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index 9e82dd7..dfc61d7 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);
@@ -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);
--
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.
^ permalink raw reply related [flat|nested] 2+ messages in thread* [PATCH V3] arm64: tlbflush: avoid writing RES0 bits
2018-03-28 1:55 [PATCH V3] arm64: tlbflush: avoid writing RES0 bits Philip Elcan
@ 2018-03-28 10:19 ` Mark Rutland
0 siblings, 0 replies; 2+ messages in thread
From: Mark Rutland @ 2018-03-28 10:19 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, Mar 27, 2018 at 09:55:32PM -0400, Philip Elcan wrote:
> 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 | 25 +++++++++++++++++--------
> 1 file changed, 17 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
> index 9e82dd7..dfc61d7 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; \
> + })
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 <mark.rutland@arm.com>
Thanks,
Mark.
> +
> /*
> * 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);
> --
> 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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