[PATCH] RISC-V: selftests: cbo: Use exported __cpu_to_le32() with uapi header

[Woodrow Shen]

Short background: while I'm building the riscv/hwprobe tests, it seems
I always hit the "error: impossible constraint in 'asm'" even though
the commit https://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git/commit/tools/testing/selftests/riscv/hwprobe/cbo.c?id=0de65288d75ff96c30e216557d979fb9342c4323
is applied. I'm not sure if this only happens to me as I tried to
build them on a clean debian chroot. To apply this patch makes the
build happy, but if there is no need to change, please ignore this
patch.

And sorry to forget cc more maintainers for reviewing.

Cheers,
Woodrow


On Thu, Mar 21, 2024 at 7:52 PM <woodrow.shen at sifive.com> wrote:
>
> From: Hsieh-Tseng Shen <woodrow.shen at sifive.com>
>
> cpu_to_le32 is not defined in uapi headers, and it could cause an error
> of impossible constraint in 'asm' during compilation. However,
> the reason is due to undefined reference to cpu_to_le32.
> __cpu_to_le32() defined from byteorder.h should be used instead.
>
> Signed-off-by: Hsieh-Tseng Shen <woodrow.shen at sifive.com>
> ---
>  tools/testing/selftests/riscv/hwprobe/cbo.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/riscv/hwprobe/cbo.c b/tools/testing/selftests/riscv/hwprobe/cbo.c
> index c537d52fafc5..b2dd18b3e360 100644
> --- a/tools/testing/selftests/riscv/hwprobe/cbo.c
> +++ b/tools/testing/selftests/riscv/hwprobe/cbo.c
> @@ -15,11 +15,12 @@
>  #include <linux/compiler.h>
>  #include <linux/kernel.h>
>  #include <asm/ucontext.h>
> +#include <asm/byteorder.h>
>
>  #include "hwprobe.h"
>  #include "../../kselftest.h"
>
> -#define MK_CBO(fn) cpu_to_le32((fn) << 20 | 10 << 15 | 2 << 12 | 0 << 7 | 15)
> +#define MK_CBO(fn) __cpu_to_le32((fn) << 20 | 10 << 15 | 2 << 12 | 0 << 7 | 15)
>
>  static char mem[4096] __aligned(4096) = { [0 ... 4095] = 0xa5 };
>
> --
> 2.34.1
>