Re: [PATCH v3 04/13] riscv: hwcap: make ISA extension ids can be used in asm

From: Jisheng Zhang
Date: Sun Jan 15 2023 - 08:24:26 EST


On Thu, Jan 12, 2023 at 09:28:55PM +0000, Conor Dooley wrote:
> Hey Jisheng,

Hi Conor,

>
> On Thu, Jan 12, 2023 at 01:10:18AM +0800, Jisheng Zhang wrote:
> > We will make use of ISA extension in asm files, so make the multi-letter
> >
> > RISC-V ISA extension IDs macros rather than enums and move them and
> > those base ISA extension IDs to suitable place.
>
> From v2:
> Which base ISA extension IDs? Changelog should match the patch contents,
> and it's a little unclear here since the base ISA extension IDs are
> visible here but in the context not the diff.

"that is not what git thinks you did" is the key, see below.

>
> How about something like:
> "So that ISA extensions can be used in assembly files, convert the
> multi-letter RISC-V ISA extension IDs enums to macros.
> In order to make them visible, move the #ifndef __ASSEMBLY__ guard
> to a later point in the header"

This commit msg looks better, thanks.
>
> Pedantry perhaps, but referring to moving the base IDs looks odd, since
> that is not what git thinks you did - even if that is the copy paste

Aha, this is the key, I moved the base IDs out side of __ASSEMBLY__
macro protection and move extension IDs to macros, but the git doesn't
think I did the base IDs moving ;)

> operation you carried out.
>
> Content itself is
> Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>
> Thanks,
> Conor.
>
> > Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
> > Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>
> > Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
> > ---
> > arch/riscv/include/asm/hwcap.h | 45 ++++++++++++++++------------------
> > 1 file changed, 21 insertions(+), 24 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> > index 86328e3acb02..09a7767723f6 100644
> > --- a/arch/riscv/include/asm/hwcap.h
> > +++ b/arch/riscv/include/asm/hwcap.h
> > @@ -12,20 +12,6 @@
> > #include <linux/bits.h>
> > #include <uapi/asm/hwcap.h>
> >
> > -#ifndef __ASSEMBLY__
> > -#include <linux/jump_label.h>
> > -/*
> > - * This yields a mask that user programs can use to figure out what
> > - * instruction set this cpu supports.
> > - */
> > -#define ELF_HWCAP (elf_hwcap)
> > -
> > -enum {
> > - CAP_HWCAP = 1,
> > -};
> > -
> > -extern unsigned long elf_hwcap;
> > -
> > #define RISCV_ISA_EXT_a ('a' - 'a')
> > #define RISCV_ISA_EXT_c ('c' - 'a')
> > #define RISCV_ISA_EXT_d ('d' - 'a')
> > @@ -46,22 +32,33 @@ extern unsigned long elf_hwcap;
> > #define RISCV_ISA_EXT_BASE 26
> >
> > /*
> > - * This enum represent the logical ID for each multi-letter RISC-V ISA extension.
> > + * These macros represent the logical ID for each multi-letter RISC-V ISA extension.
> > * The logical ID should start from RISCV_ISA_EXT_BASE and must not exceed
> > * RISCV_ISA_EXT_MAX. 0-25 range is reserved for single letter
> > * extensions while all the multi-letter extensions should define the next
> > * available logical extension id.
> > */
> > -enum riscv_isa_ext_id {
> > - RISCV_ISA_EXT_SSCOFPMF = RISCV_ISA_EXT_BASE,
> > - RISCV_ISA_EXT_SVPBMT,
> > - RISCV_ISA_EXT_ZICBOM,
> > - RISCV_ISA_EXT_ZIHINTPAUSE,
> > - RISCV_ISA_EXT_SSTC,
> > - RISCV_ISA_EXT_SVINVAL,
> > - RISCV_ISA_EXT_ID_MAX
> > +#define RISCV_ISA_EXT_SSCOFPMF 26
> > +#define RISCV_ISA_EXT_SVPBMT 27
> > +#define RISCV_ISA_EXT_ZICBOM 28
> > +#define RISCV_ISA_EXT_ZIHINTPAUSE 29
> > +#define RISCV_ISA_EXT_SSTC 30
> > +#define RISCV_ISA_EXT_SVINVAL 31
> > +
> > +#ifndef __ASSEMBLY__
> > +#include <linux/jump_label.h>
> > +/*
> > + * This yields a mask that user programs can use to figure out what
> > + * instruction set this cpu supports.
> > + */
> > +#define ELF_HWCAP (elf_hwcap)
> > +
> > +enum {
> > + CAP_HWCAP = 1,
> > };
> > -static_assert(RISCV_ISA_EXT_ID_MAX <= RISCV_ISA_EXT_MAX);
> > +
> > +extern unsigned long elf_hwcap;
> > +
> >
> > /*
> > * This enum represents the logical ID for each RISC-V ISA extension static
> > --
> > 2.38.1
> >
> >
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