On Wed, Feb 21, 2024 at 11:04:22PM +0200, Andy Shevchenko wrote:
On Wed, Feb 21, 2024 at 10:30:02PM +0200, Dmitry Baryshkov wrote:
On Thu, 8 Feb 2024 at 09:45, Lucas De Marchi <lucas.demarchi@xxxxxxxxx> wrote:
...
> +#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
Can sizeof() be used in assembly?
...
> -#define __GENMASK(h, l) \
> - (((~UL(0)) - (UL(1) << (l)) + 1) & \
> - (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
> -#define GENMASK(h, l) \
> - (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
> +#define __GENMASK(t, h, l) \
> + (GENMASK_INPUT_CHECK(h, l) + \
> + (((t)~0ULL - ((t)(1) << (l)) + 1) & \
> + ((t)~0ULL >> (BITS_PER_TYPE(t) - 1 - (h)))))
Nevertheless, the use ~0ULL is not proper assembly, this broke initial
implementation using UL() / ULL().
indeed.
> -#define __GENMASK_ULL(h, l) \
> - (((~ULL(0)) - (ULL(1) << (l)) + 1) & \
> - (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
> -#define GENMASK_ULL(h, l) \
> - (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
Ditto.
problem here seems actually because of the cast to the final type. My
previous impl was avoiding that, but was too verbose compared to this.
I will look at reverting this.
Lucas De Marchi
> +#define GENMASK(h, l) __GENMASK(unsigned long, h, l)
> +#define GENMASK_ULL(h, l) __GENMASK(unsigned long long, h, l)
> +#define GENMASK_U8(h, l) __GENMASK(u8, h, l)
> +#define GENMASK_U16(h, l) __GENMASK(u16, h, l)
> +#define GENMASK_U32(h, l) __GENMASK(u32, h, l)
> +#define GENMASK_U64(h, l) __GENMASK(u64, h, l)
This breaks drm-tip on arm64 architecture:
arch/arm64/kernel/entry-fpsimd.S: Assembler messages:
465arch/arm64/kernel/entry-fpsimd.S:271: Error: found 'l', expected: ')'
466arch/arm64/kernel/entry-fpsimd.S:66: Info: macro invoked from here
467arch/arm64/kernel/entry-fpsimd.S:271: Error: found 'l', expected: ')'
468arch/arm64/kernel/entry-fpsimd.S:66: Info: macro invoked from here
469arch/arm64/kernel/entry-fpsimd.S:271: Error: found 'l', expected: ')'
470arch/arm64/kernel/entry-fpsimd.S:66: Info: macro invoked from here
471arch/arm64/kernel/entry-fpsimd.S:271: Error: found 'l', expected: ')'
472arch/arm64/kernel/entry-fpsimd.S:66: Info: macro invoked from here
473arch/arm64/kernel/entry-fpsimd.S:271: Error: unexpected characters
following instruction at operand 3 -- `bic x2,x1,(0+(((unsigned
long)~0ULL-((unsigned long)(1)<<(0))+1)&((unsigned
long)~0ULL>>((sizeof(unsigned long)*8)-1-(3)))))'
474arch/arm64/kernel/entry-fpsimd.S:66: Info: macro invoked from here
475arch/arm64/kernel/entry-fpsimd.S:282: Error: found 'l', expected: ')'
476arch/arm64/kernel/entry-fpsimd.S:98: Info: macro invoked from here
477arch/arm64/kernel/entry-fpsimd.S:282: Error: found 'l', expected: ')'
478arch/arm64/kernel/entry-fpsimd.S:98: Info: macro invoked from here
479arch/arm64/kernel/entry-fpsimd.S:282: Error: found 'l', expected: ')'
480arch/arm64/kernel/entry-fpsimd.S:98: Info: macro invoked from here
481arch/arm64/kernel/entry-fpsimd.S:282: Error: found 'l', expected: ')'
482arch/arm64/kernel/entry-fpsimd.S:98: Info: macro invoked from here
483arch/arm64/kernel/entry-fpsimd.S:282: Error: unexpected characters
following instruction at operand 3 -- `bic x2,x1,(0+(((unsigned
long)~0ULL-((unsigned long)(1)<<(0))+1)&((unsigned
long)~0ULL>>((sizeof(unsigned long)*8)-1-(3)))))'
484arch/arm64/kernel/entry-fpsimd.S:98: Info: macro invoked from here
--
With Best Regards,
Andy Shevchenko
