lkml.org 
[lkml]   [2019]   [Apr]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RESEND PATCH v3 02/11] arm64: mark (__)cpus_have_const_cap as __always_inline
[adding relevant arm64 folk to Cc]

On Tue, Apr 23, 2019 at 12:49:50PM +0900, Masahiro Yamada wrote:
> This prepares to move CONFIG_OPTIMIZE_INLINING from x86 to a common
> place. We need to eliminate potential issues beforehand.
>
> If it is enabled for arm64, the following errors are reported:
>
> In file included from ././include/linux/compiler_types.h:68,
> from <command-line>:
> ./arch/arm64/include/asm/jump_label.h: In function 'cpus_have_const_cap':
> ./include/linux/compiler-gcc.h:120:38: warning: asm operand 0 probably doesn't match constraints
> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
> ^~~
> ./arch/arm64/include/asm/jump_label.h:32:2: note: in expansion of macro 'asm_volatile_goto'
> asm_volatile_goto(
> ^~~~~~~~~~~~~~~~~
> ./include/linux/compiler-gcc.h:120:38: error: impossible constraint in 'asm'
> #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
> ^~~
> ./arch/arm64/include/asm/jump_label.h:32:2: note: in expansion of macro 'asm_volatile_goto'
> asm_volatile_goto(
> ^~~~~~~~~~~~~~~~~
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

This looks sound to me, and from a quick scan of v5.1-rc6 with:

$ git grep -wW inline -- arch/arm64

... I didn't spot any other sites which obviously needed to be made
__always_inline.

I've built and booted this atop of defconfig and my usual suite of debug
options for fuzzing, at EL1 under QEMU/KVM, and at EL2 under QEMU/TCG,
with no issues in either case, so FWIW:

Tested-by: Mark Rutland <mark.rutland@arm.com>

Thanks,
Mark.

> ---
>
> Changes in v3: None
> Changes in v2:
> - split into a separate patch
>
> arch/arm64/include/asm/cpufeature.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
> index e505e1fbd2b9..77d1aa57323e 100644
> --- a/arch/arm64/include/asm/cpufeature.h
> +++ b/arch/arm64/include/asm/cpufeature.h
> @@ -406,7 +406,7 @@ static inline bool cpu_have_feature(unsigned int num)
> }
>
> /* System capability check for constant caps */
> -static inline bool __cpus_have_const_cap(int num)
> +static __always_inline bool __cpus_have_const_cap(int num)
> {
> if (num >= ARM64_NCAPS)
> return false;
> @@ -420,7 +420,7 @@ static inline bool cpus_have_cap(unsigned int num)
> return test_bit(num, cpu_hwcaps);
> }
>
> -static inline bool cpus_have_const_cap(int num)
> +static __always_inline bool cpus_have_const_cap(int num)
> {
> if (static_branch_likely(&arm64_const_caps_ready))
> return __cpus_have_const_cap(num);
> --
> 2.17.1
>

\
 
 \ /
  Last update: 2019-04-23 13:32    [W:0.243 / U:2.516 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site