| Message ID | 1572904606-27961-1-git-send-email-bhsharma@redhat.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 218564b164ad9d283d3cb3d5367705726123a610 |
| Headers | show |
| Series | arm64: mm: Remove MAX_USER_VA_BITS definition | expand |
On Tue, Nov 05, 2019 at 03:26:46AM +0530, Bhupesh Sharma wrote: > commit 9b31cf493ffa ("arm64: mm: Introduce MAX_USER_VA_BITS definition") > introduced the MAX_USER_VA_BITS definition, which was used to support > the arm64 mm use-cases where the user-space could use 52-bit virtual > addresses whereas the kernel-space would still could a maximum of 48-bit > virtual addressing. > > But, now with commit b6d00d47e81a ("arm64: mm: Introduce 52-bit Kernel > VAs"), we removed the 52-bit user/48-bit kernel kconfig option and hence > there is no longer any scenario where user VA != kernel VA size > (even with CONFIG_ARM64_FORCE_52BIT enabled, the same is true). > > Hence we can do away with the MAX_USER_VA_BITS macro as it is equal to > VA_BITS (maximum VA space size) in all possible use-cases. Note that > even though the 'vabits_actual' value would be 48 for arm64 hardware > which don't support LVA-8.2 extension (even when CONFIG_ARM64_VA_BITS_52 > is enabled), VA_BITS would still be set to a value 52. Hence this change > would be safe in all possible VA address space combinations. > > Cc: James Morse <james.morse@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Will Deacon <will@kernel.org> > Cc: Steve Capper <steve.capper@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> > Cc: linux-kernel@vger.kernel.org > Cc: kexec@lists.infradead.org > Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com> As the commit message says, there should be no functional change as a result of this patch, and it looks like a nice cleanup to me: Reviewed-by: Mark Rutland <mark.rutland@arm.com> Mark. > --- > arch/arm64/include/asm/memory.h | 6 ------ > arch/arm64/include/asm/pgtable-hwdef.h | 2 +- > arch/arm64/include/asm/processor.h | 2 +- > 3 files changed, 2 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > index c23c47360664..a4f9ca5479b0 100644 > --- a/arch/arm64/include/asm/memory.h > +++ b/arch/arm64/include/asm/memory.h > @@ -69,12 +69,6 @@ > #define KERNEL_START _text > #define KERNEL_END _end > > -#ifdef CONFIG_ARM64_VA_BITS_52 > -#define MAX_USER_VA_BITS 52 > -#else > -#define MAX_USER_VA_BITS VA_BITS > -#endif > - > /* > * Generic and tag-based KASAN require 1/8th and 1/16th of the kernel virtual > * address space for the shadow region respectively. They can bloat the stack > diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h > index 3df60f97da1f..d9fbd433cc17 100644 > --- a/arch/arm64/include/asm/pgtable-hwdef.h > +++ b/arch/arm64/include/asm/pgtable-hwdef.h > @@ -69,7 +69,7 @@ > #define PGDIR_SHIFT ARM64_HW_PGTABLE_LEVEL_SHIFT(4 - CONFIG_PGTABLE_LEVELS) > #define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT) > #define PGDIR_MASK (~(PGDIR_SIZE-1)) > -#define PTRS_PER_PGD (1 << (MAX_USER_VA_BITS - PGDIR_SHIFT)) > +#define PTRS_PER_PGD (1 << (VA_BITS - PGDIR_SHIFT)) > > /* > * Section address mask and size definitions. > diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h > index 5623685c7d13..586fcd4b1965 100644 > --- a/arch/arm64/include/asm/processor.h > +++ b/arch/arm64/include/asm/processor.h > @@ -9,7 +9,7 @@ > #define __ASM_PROCESSOR_H > > #define KERNEL_DS UL(-1) > -#define USER_DS ((UL(1) << MAX_USER_VA_BITS) - 1) > +#define USER_DS ((UL(1) << VA_BITS) - 1) > > /* > * On arm64 systems, unaligned accesses by the CPU are cheap, and so there is > -- > 2.7.4 >
On Tue, Nov 05, 2019 at 03:26:46AM +0530, Bhupesh Sharma wrote: > commit 9b31cf493ffa ("arm64: mm: Introduce MAX_USER_VA_BITS definition") > introduced the MAX_USER_VA_BITS definition, which was used to support > the arm64 mm use-cases where the user-space could use 52-bit virtual > addresses whereas the kernel-space would still could a maximum of 48-bit > virtual addressing. > > But, now with commit b6d00d47e81a ("arm64: mm: Introduce 52-bit Kernel > VAs"), we removed the 52-bit user/48-bit kernel kconfig option and hence > there is no longer any scenario where user VA != kernel VA size > (even with CONFIG_ARM64_FORCE_52BIT enabled, the same is true). > > Hence we can do away with the MAX_USER_VA_BITS macro as it is equal to > VA_BITS (maximum VA space size) in all possible use-cases. Note that > even though the 'vabits_actual' value would be 48 for arm64 hardware > which don't support LVA-8.2 extension (even when CONFIG_ARM64_VA_BITS_52 > is enabled), VA_BITS would still be set to a value 52. Hence this change > would be safe in all possible VA address space combinations. > > Cc: James Morse <james.morse@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Will Deacon <will@kernel.org> > Cc: Steve Capper <steve.capper@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> > Cc: linux-kernel@vger.kernel.org > Cc: kexec@lists.infradead.org > Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com> Queued for 5.5. Thanks.
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index c23c47360664..a4f9ca5479b0 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -69,12 +69,6 @@ #define KERNEL_START _text #define KERNEL_END _end -#ifdef CONFIG_ARM64_VA_BITS_52 -#define MAX_USER_VA_BITS 52 -#else -#define MAX_USER_VA_BITS VA_BITS -#endif - /* * Generic and tag-based KASAN require 1/8th and 1/16th of the kernel virtual * address space for the shadow region respectively. They can bloat the stack diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index 3df60f97da1f..d9fbd433cc17 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -69,7 +69,7 @@ #define PGDIR_SHIFT ARM64_HW_PGTABLE_LEVEL_SHIFT(4 - CONFIG_PGTABLE_LEVELS) #define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT) #define PGDIR_MASK (~(PGDIR_SIZE-1)) -#define PTRS_PER_PGD (1 << (MAX_USER_VA_BITS - PGDIR_SHIFT)) +#define PTRS_PER_PGD (1 << (VA_BITS - PGDIR_SHIFT)) /* * Section address mask and size definitions. diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 5623685c7d13..586fcd4b1965 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -9,7 +9,7 @@ #define __ASM_PROCESSOR_H #define KERNEL_DS UL(-1) -#define USER_DS ((UL(1) << MAX_USER_VA_BITS) - 1) +#define USER_DS ((UL(1) << VA_BITS) - 1) /* * On arm64 systems, unaligned accesses by the CPU are cheap, and so there is
commit 9b31cf493ffa ("arm64: mm: Introduce MAX_USER_VA_BITS definition") introduced the MAX_USER_VA_BITS definition, which was used to support the arm64 mm use-cases where the user-space could use 52-bit virtual addresses whereas the kernel-space would still could a maximum of 48-bit virtual addressing. But, now with commit b6d00d47e81a ("arm64: mm: Introduce 52-bit Kernel VAs"), we removed the 52-bit user/48-bit kernel kconfig option and hence there is no longer any scenario where user VA != kernel VA size (even with CONFIG_ARM64_FORCE_52BIT enabled, the same is true). Hence we can do away with the MAX_USER_VA_BITS macro as it is equal to VA_BITS (maximum VA space size) in all possible use-cases. Note that even though the 'vabits_actual' value would be 48 for arm64 hardware which don't support LVA-8.2 extension (even when CONFIG_ARM64_VA_BITS_52 is enabled), VA_BITS would still be set to a value 52. Hence this change would be safe in all possible VA address space combinations. Cc: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Steve Capper <steve.capper@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: linux-kernel@vger.kernel.org Cc: kexec@lists.infradead.org Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com> --- arch/arm64/include/asm/memory.h | 6 ------ arch/arm64/include/asm/pgtable-hwdef.h | 2 +- arch/arm64/include/asm/processor.h | 2 +- 3 files changed, 2 insertions(+), 8 deletions(-)