| Message ID | 1512563739-25239-20-git-send-email-will.deacon@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: Unmap the kernel whilst running in userspace (KPTI) | expand |
On Wed, Dec 06, 2017 at 12:35:38PM +0000, Will Deacon wrote: > There are now a handful of open-coded masks to extract the ASID from a > TTBR value, so introduce a TTBR_ASID_MASK and use that instead. > > Suggested-by: Mark Rutland <mark.rutland@arm.com> > Signed-off-by: Will Deacon <will.deacon@arm.com> Thanks! Reviewed-by: Mark Rutland <mark.rutland@arm.com> Mark. > --- > arch/arm64/include/asm/asm-uaccess.h | 3 ++- > arch/arm64/include/asm/mmu.h | 1 + > arch/arm64/include/asm/uaccess.h | 4 ++-- > arch/arm64/kernel/entry.S | 2 +- > 4 files changed, 6 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h > index 21b8cf304028..f4f234b6155e 100644 > --- a/arch/arm64/include/asm/asm-uaccess.h > +++ b/arch/arm64/include/asm/asm-uaccess.h > @@ -4,6 +4,7 @@ > > #include <asm/alternative.h> > #include <asm/kernel-pgtable.h> > +#include <asm/mmu.h> > #include <asm/sysreg.h> > #include <asm/assembler.h> > > @@ -17,7 +18,7 @@ > msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 > isb > sub \tmp1, \tmp1, #SWAPPER_DIR_SIZE > - bic \tmp1, \tmp1, #(0xffff << 48) > + bic \tmp1, \tmp1, #TTBR_ASID_MASK > msr ttbr1_el1, \tmp1 // set reserved ASID > isb > .endm > diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h > index da6f12e40714..6f7bdb89817f 100644 > --- a/arch/arm64/include/asm/mmu.h > +++ b/arch/arm64/include/asm/mmu.h > @@ -18,6 +18,7 @@ > > #define MMCF_AARCH32 0x1 /* mm context flag for AArch32 executables */ > #define USER_ASID_FLAG (UL(1) << 48) > +#define TTBR_ASID_MASK (UL(0xffff) << 48) > > #ifndef __ASSEMBLY__ > > diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h > index 750a3b76a01c..6eadf55ebaf0 100644 > --- a/arch/arm64/include/asm/uaccess.h > +++ b/arch/arm64/include/asm/uaccess.h > @@ -112,7 +112,7 @@ static inline void __uaccess_ttbr0_disable(void) > write_sysreg(ttbr + SWAPPER_DIR_SIZE, ttbr0_el1); > isb(); > /* Set reserved ASID */ > - ttbr &= ~(0xffffUL << 48); > + ttbr &= ~TTBR_ASID_MASK; > write_sysreg(ttbr, ttbr1_el1); > isb(); > } > @@ -131,7 +131,7 @@ static inline void __uaccess_ttbr0_enable(void) > > /* Restore active ASID */ > ttbr1 = read_sysreg(ttbr1_el1); > - ttbr1 |= ttbr0 & (0xffffUL << 48); > + ttbr1 |= ttbr0 & TTBR_ASID_MASK; > write_sysreg(ttbr1, ttbr1_el1); > isb(); > > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index 5d51bdbb2131..3eabcb194c87 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -205,7 +205,7 @@ alternative_else_nop_endif > > .if \el != 0 > mrs x21, ttbr1_el1 > - tst x21, #0xffff << 48 // Check for the reserved ASID > + tst x21, #TTBR_ASID_MASK // Check for the reserved ASID > orr x23, x23, #PSR_PAN_BIT // Set the emulated PAN in the saved SPSR > b.eq 1f // TTBR0 access already disabled > and x23, x23, #~PSR_PAN_BIT // Clear the emulated PAN in the saved SPSR > -- > 2.1.4 >
diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h index 21b8cf304028..f4f234b6155e 100644 --- a/arch/arm64/include/asm/asm-uaccess.h +++ b/arch/arm64/include/asm/asm-uaccess.h @@ -4,6 +4,7 @@ #include <asm/alternative.h> #include <asm/kernel-pgtable.h> +#include <asm/mmu.h> #include <asm/sysreg.h> #include <asm/assembler.h> @@ -17,7 +18,7 @@ msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 isb sub \tmp1, \tmp1, #SWAPPER_DIR_SIZE - bic \tmp1, \tmp1, #(0xffff << 48) + bic \tmp1, \tmp1, #TTBR_ASID_MASK msr ttbr1_el1, \tmp1 // set reserved ASID isb .endm diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h index da6f12e40714..6f7bdb89817f 100644 --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -18,6 +18,7 @@ #define MMCF_AARCH32 0x1 /* mm context flag for AArch32 executables */ #define USER_ASID_FLAG (UL(1) << 48) +#define TTBR_ASID_MASK (UL(0xffff) << 48) #ifndef __ASSEMBLY__ diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 750a3b76a01c..6eadf55ebaf0 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -112,7 +112,7 @@ static inline void __uaccess_ttbr0_disable(void) write_sysreg(ttbr + SWAPPER_DIR_SIZE, ttbr0_el1); isb(); /* Set reserved ASID */ - ttbr &= ~(0xffffUL << 48); + ttbr &= ~TTBR_ASID_MASK; write_sysreg(ttbr, ttbr1_el1); isb(); } @@ -131,7 +131,7 @@ static inline void __uaccess_ttbr0_enable(void) /* Restore active ASID */ ttbr1 = read_sysreg(ttbr1_el1); - ttbr1 |= ttbr0 & (0xffffUL << 48); + ttbr1 |= ttbr0 & TTBR_ASID_MASK; write_sysreg(ttbr1, ttbr1_el1); isb(); diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 5d51bdbb2131..3eabcb194c87 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -205,7 +205,7 @@ alternative_else_nop_endif .if \el != 0 mrs x21, ttbr1_el1 - tst x21, #0xffff << 48 // Check for the reserved ASID + tst x21, #TTBR_ASID_MASK // Check for the reserved ASID orr x23, x23, #PSR_PAN_BIT // Set the emulated PAN in the saved SPSR b.eq 1f // TTBR0 access already disabled and x23, x23, #~PSR_PAN_BIT // Clear the emulated PAN in the saved SPSR
There are now a handful of open-coded masks to extract the ASID from a TTBR value, so introduce a TTBR_ASID_MASK and use that instead. Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm64/include/asm/asm-uaccess.h | 3 ++- arch/arm64/include/asm/mmu.h | 1 + arch/arm64/include/asm/uaccess.h | 4 ++-- arch/arm64/kernel/entry.S | 2 +- 4 files changed, 6 insertions(+), 4 deletions(-) -- 2.1.4