| Message ID | 1395927591-20938-1-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thu, Mar 27, 2014 at 8:39 AM, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > The generic asm/unaligned.h does not allow unaligned accesses, resulting in all > invocations of get_unaligned_xxx() and put_unaligned_xxx() to be expanded into > byte size accesses. On arm64, this is unnecessary, so provide a more permissive > asm/unaligned.h instead. Couldn't the generic version learn to use CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS on arches that enable it? Rob
On 27 March 2014 15:15, Rob Herring <robherring2@gmail.com> wrote: > On Thu, Mar 27, 2014 at 8:39 AM, Ard Biesheuvel > <ard.biesheuvel@linaro.org> wrote: >> The generic asm/unaligned.h does not allow unaligned accesses, resulting in all >> invocations of get_unaligned_xxx() and put_unaligned_xxx() to be expanded into >> byte size accesses. On arm64, this is unnecessary, so provide a more permissive >> asm/unaligned.h instead. > > Couldn't the generic version learn to use > CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS on arches that enable it? > I wasn't aware of that option, but I agree that it seems reasonable to test for that in the asm-generic version.
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild index 43a2c9d2d6f4..f88986a0c1dd 100644 --- a/arch/arm64/include/asm/Kbuild +++ b/arch/arm64/include/asm/Kbuild @@ -46,7 +46,6 @@ generic-y += termios.h generic-y += topology.h generic-y += trace_clock.h generic-y += types.h -generic-y += unaligned.h generic-y += user.h generic-y += vga.h generic-y += xor.h diff --git a/arch/arm64/include/asm/unaligned.h b/arch/arm64/include/asm/unaligned.h new file mode 100644 index 000000000000..00c4a4e02fd1 --- /dev/null +++ b/arch/arm64/include/asm/unaligned.h @@ -0,0 +1,17 @@ +#ifndef __ASM_UNALIGNED_H +#define __ASM_UNALIGNED_H + +#include <linux/unaligned/access_ok.h> +#include <linux/unaligned/generic.h> + +#if defined(__LITTLE_ENDIAN) +#define get_unaligned __get_unaligned_le +#define put_unaligned __put_unaligned_le +#elif defined(__BIG_ENDIAN) +#define get_unaligned __get_unaligned_be +#define put_unaligned __put_unaligned_be +#else +#error need to define endianess +#endif + +#endif /* __ASM_UNALIGNED_H */
The generic asm/unaligned.h does not allow unaligned accesses, resulting in all invocations of get_unaligned_xxx() and put_unaligned_xxx() to be expanded into byte size accesses. On arm64, this is unnecessary, so provide a more permissive asm/unaligned.h instead. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/include/asm/Kbuild | 1 - arch/arm64/include/asm/unaligned.h | 17 +++++++++++++++++ 2 files changed, 17 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/unaligned.h