| Message ID | 1456174472-30028-11-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Mon, Feb 22, 2016 at 09:54:32PM +0100, Ard Biesheuvel wrote: > Now that we have replaced all occurrences of __pa() translations > involving virtual addresses that are covered by the kernel text, > we can redefine __virt_to_phys and __pa() etc to only take virtual > address that are covered by the linear mapping. This means we can > remove the comparison with PAGE_OFFSET in the definition of > __virt_to_phys(). > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > arch/arm64/include/asm/memory.h | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > index 56d6739430f3..3b5dc5b243ac 100644 > --- a/arch/arm64/include/asm/memory.h > +++ b/arch/arm64/include/asm/memory.h > @@ -86,11 +86,14 @@ > * private definitions which should NOT be used outside memory.h > * files. Use virt_to_phys/phys_to_virt/__pa/__va instead. > */ > -#define __virt_to_phys(x) ({ \ > +#ifndef CONFIG_DEBUG_VM > +#define __virt_to_phys(x) (((phys_addr_t)(x) & ~PAGE_OFFSET) + PHYS_OFFSET) > +#else > +#define __virt_to_phys(x) ({ \ > phys_addr_t __x = (phys_addr_t)(x); \ > - __x & BIT(VA_BITS - 1) ? (__x & ~PAGE_OFFSET) + PHYS_OFFSET : \ > - (__x - kimage_voffset); }) > - > + BUG_ON(__x < PAGE_OFFSET); \ > + (((phys_addr_t)__x & ~PAGE_OFFSET) + PHYS_OFFSET); }) What's the #include-hell like if you try to use VM_BUG_ON instead? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On 23 February 2016 at 13:26, Will Deacon <will.deacon@arm.com> wrote: > On Mon, Feb 22, 2016 at 09:54:32PM +0100, Ard Biesheuvel wrote: >> Now that we have replaced all occurrences of __pa() translations >> involving virtual addresses that are covered by the kernel text, >> we can redefine __virt_to_phys and __pa() etc to only take virtual >> address that are covered by the linear mapping. This means we can >> remove the comparison with PAGE_OFFSET in the definition of >> __virt_to_phys(). >> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> >> --- >> arch/arm64/include/asm/memory.h | 12 +++++++----- >> 1 file changed, 7 insertions(+), 5 deletions(-) >> >> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h >> index 56d6739430f3..3b5dc5b243ac 100644 >> --- a/arch/arm64/include/asm/memory.h >> +++ b/arch/arm64/include/asm/memory.h >> @@ -86,11 +86,14 @@ >> * private definitions which should NOT be used outside memory.h >> * files. Use virt_to_phys/phys_to_virt/__pa/__va instead. >> */ >> -#define __virt_to_phys(x) ({ \ >> +#ifndef CONFIG_DEBUG_VM >> +#define __virt_to_phys(x) (((phys_addr_t)(x) & ~PAGE_OFFSET) + PHYS_OFFSET) >> +#else >> +#define __virt_to_phys(x) ({ \ >> phys_addr_t __x = (phys_addr_t)(x); \ >> - __x & BIT(VA_BITS - 1) ? (__x & ~PAGE_OFFSET) + PHYS_OFFSET : \ >> - (__x - kimage_voffset); }) >> - >> + BUG_ON(__x < PAGE_OFFSET); \ >> + (((phys_addr_t)__x & ~PAGE_OFFSET) + PHYS_OFFSET); }) > > What's the #include-hell like if you try to use VM_BUG_ON instead? > The #include hell would not change I think, since include/linux/mmdebug.h:18:#define VM_BUG_ON(cond) BUG_ON(cond) but it would certainly make this code look a lot cleaner. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Tue, Feb 23, 2016 at 01:29:21PM +0100, Ard Biesheuvel wrote: > On 23 February 2016 at 13:26, Will Deacon <will.deacon@arm.com> wrote: > > On Mon, Feb 22, 2016 at 09:54:32PM +0100, Ard Biesheuvel wrote: > >> Now that we have replaced all occurrences of __pa() translations > >> involving virtual addresses that are covered by the kernel text, > >> we can redefine __virt_to_phys and __pa() etc to only take virtual > >> address that are covered by the linear mapping. This means we can > >> remove the comparison with PAGE_OFFSET in the definition of > >> __virt_to_phys(). > >> > >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > >> --- > >> arch/arm64/include/asm/memory.h | 12 +++++++----- > >> 1 file changed, 7 insertions(+), 5 deletions(-) > >> > >> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > >> index 56d6739430f3..3b5dc5b243ac 100644 > >> --- a/arch/arm64/include/asm/memory.h > >> +++ b/arch/arm64/include/asm/memory.h > >> @@ -86,11 +86,14 @@ > >> * private definitions which should NOT be used outside memory.h > >> * files. Use virt_to_phys/phys_to_virt/__pa/__va instead. > >> */ > >> -#define __virt_to_phys(x) ({ \ > >> +#ifndef CONFIG_DEBUG_VM > >> +#define __virt_to_phys(x) (((phys_addr_t)(x) & ~PAGE_OFFSET) + PHYS_OFFSET) > >> +#else > >> +#define __virt_to_phys(x) ({ \ > >> phys_addr_t __x = (phys_addr_t)(x); \ > >> - __x & BIT(VA_BITS - 1) ? (__x & ~PAGE_OFFSET) + PHYS_OFFSET : \ > >> - (__x - kimage_voffset); }) > >> - > >> + BUG_ON(__x < PAGE_OFFSET); \ > >> + (((phys_addr_t)__x & ~PAGE_OFFSET) + PHYS_OFFSET); }) > > > > What's the #include-hell like if you try to use VM_BUG_ON instead? > > > > The #include hell would not change I think, since > > include/linux/mmdebug.h:18:#define VM_BUG_ON(cond) BUG_ON(cond) > > but it would certainly make this code look a lot cleaner. Yup, and likewise for PHYS_OFFSET. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 56d6739430f3..3b5dc5b243ac 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -86,11 +86,14 @@ * private definitions which should NOT be used outside memory.h * files. Use virt_to_phys/phys_to_virt/__pa/__va instead. */ -#define __virt_to_phys(x) ({ \ +#ifndef CONFIG_DEBUG_VM +#define __virt_to_phys(x) (((phys_addr_t)(x) & ~PAGE_OFFSET) + PHYS_OFFSET) +#else +#define __virt_to_phys(x) ({ \ phys_addr_t __x = (phys_addr_t)(x); \ - __x & BIT(VA_BITS - 1) ? (__x & ~PAGE_OFFSET) + PHYS_OFFSET : \ - (__x - kimage_voffset); }) - + BUG_ON(__x < PAGE_OFFSET); \ + (((phys_addr_t)__x & ~PAGE_OFFSET) + PHYS_OFFSET); }) +#endif #define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET) | PAGE_OFFSET) #define __kimg_to_phys(x) ((phys_addr_t)(x) - kimage_voffset) @@ -134,7 +137,6 @@ #endif #ifndef __ASSEMBLY__ -#include <linux/bitops.h> extern phys_addr_t memstart_addr; /* PHYS_OFFSET - the physical address of the start of memory. */
Now that we have replaced all occurrences of __pa() translations involving virtual addresses that are covered by the kernel text, we can redefine __virt_to_phys and __pa() etc to only take virtual address that are covered by the linear mapping. This means we can remove the comparison with PAGE_OFFSET in the definition of __virt_to_phys(). Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/include/asm/memory.h | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) -- 2.5.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel