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

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Message-ID: <Y8P79ap+UbyZUdZ2@xhacker>
Date:   Sun, 15 Jan 2023 21:13:25 +0800
From:   Jisheng Zhang <jszhang@...nel.org>
To:     Conor Dooley <conor@...nel.org>
Cc:     Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Anup Patel <anup@...infault.org>,
        Atish Patra <atishp@...shpatra.org>,
        Heiko Stuebner <heiko@...ech.de>,
        linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org, kvm-riscv@...ts.infradead.org,
        Andrew Jones <ajones@...tanamicro.com>
Subject: Re: [PATCH v3 04/13] riscv: hwcap: make ISA extension ids can be
 used in asm

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@...rochip.com>
> 
> Thanks,
> Conor.
> 
> > Signed-off-by: Jisheng Zhang <jszhang@...nel.org>
> > Reviewed-by: Heiko Stuebner <heiko@...ech.de>
> > Reviewed-by: Andrew Jones <ajones@...tanamicro.com>
> > ---
> >  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
> > 
> > 
> > _______________________________________________
> > linux-riscv mailing list
> > linux-riscv@...ts.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv

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