[PATCH V2] arm64: tlbflush: avoid writing RES0 bits
Shanker Donthineni
shankerd at codeaurora.org
Tue Mar 27 07:53:16 PDT 2018
On 03/27/2018 06:34 AM, Robin Murphy wrote:
> On 27/03/18 04:21, 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 at 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; \
>> + })
>
> I'd be inclined to make this a static inline function rather than a macro, since it doesn't need to do any wacky type-dodging, but either way the overall change now looks appropriate;
>
> Acked-by: Robin Murphy <robin.murphy at arm.com>
>
Tested-by: Shanker Donthineni <shankerd at codeaurora.org>
> Thanks,
> Robin.
>
>> +
>> /*
>> * 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);
>>
--
Shanker Donthineni
Qualcomm Datacenter Technologies, Inc. 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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