[PATCH 1/2] riscv: sbi: Remove sbi_spec_version

[Rick Chen]

Hi Bin

Bin Meng <bmeng.cn at gmail.com> 於 2020年6月1日 週一 下午5:06寫道：
>
> Hi Rick,
>
> On Mon, Jun 1, 2020 at 4:14 PM Rick Chen <rickchen36 at gmail.com> wrote:
> >
> > Hi Bin
> >
> > > From: Bin Meng [mailto:bmeng.cn at gmail.com]
> > > Sent: Wednesday, May 27, 2020 5:05 PM
> > > To: Rick Jian-Zhi Chen(陳建志); U-Boot Mailing List
> > > Cc: Atish Patra; Bin Meng
> > > Subject: [PATCH 1/2] riscv: sbi: Remove sbi_spec_version
> > >
> > > From: Bin Meng <bin.meng at windriver.com>
> > >
> > > U-Boot defaults to use SBI v0.2. Howerver there is a global variable sbi_spec_version that stills refers to v0.1. Since it is not used anywhere, let's remove it.
> > >
> > > Signed-off-by: Bin Meng <bin.meng at windriver.com>
> > > ---
> > >
> > >  arch/riscv/include/asm/sbi.h | 2 --
> > >  arch/riscv/lib/sbi.c         | 3 ---
> > >  2 files changed, 5 deletions(-)
> > >
> > > diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index 453cb5c..08e1ac0 100644
> > > --- a/arch/riscv/include/asm/sbi.h
> > > +++ b/arch/riscv/include/asm/sbi.h
> > > @@ -77,7 +77,6 @@ enum sbi_ext_rfence_fid {
> > >  #define SBI_FID_REMOTE_SFENCE_VMA_ASID SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID
> > >  #endif
> > >
> > > -#define SBI_SPEC_VERSION_DEFAULT       0x1
> > >  #define SBI_SPEC_VERSION_MAJOR_SHIFT   24
> > >  #define SBI_SPEC_VERSION_MAJOR_MASK    0x7f
> > >  #define SBI_SPEC_VERSION_MINOR_MASK    0xffffff
> > > @@ -90,7 +89,6 @@ enum sbi_ext_rfence_fid {
> > >  #define SBI_ERR_DENIED                 -4
> > >  #define SBI_ERR_INVALID_ADDRESS                -5
> > >
> > > -extern unsigned long sbi_spec_version;
> > >  struct sbiret {
> > >         long error;
> > >         long value;
> > > diff --git a/arch/riscv/lib/sbi.c b/arch/riscv/lib/sbi.c index 993597e..f298846 100644
> > > --- a/arch/riscv/lib/sbi.c
> > > +++ b/arch/riscv/lib/sbi.c
> > > @@ -11,9 +11,6 @@
> > >  #include <asm/encoding.h>
> > >  #include <asm/sbi.h>
> > >
> > > -/* default SBI version is 0.1 */
> > > -unsigned long sbi_spec_version = SBI_SPEC_VERSION_DEFAULT;
> >
> > Why not keep this variable and get version of openSbi automatically,
> > then register v01 or v02 callback function just like sbi_init() of
> > Atish' patch.
>
> I feel this is not needed anyway, because we are using Kconfig option
> to pass the same information.

U-Boot proper has been configured as SBI_V02 by default currently.
About backward compatible issue, it is not so friendly for users.
They shall select SBI_VERSION configurations correctly in U-Boot
proper and re-compile between different versions of openSbi.
If U-Boot proper can probe openSbi and switch V01 or V02 mode
automatically, users can run smoothly without awareness of SBI
versions.

Thanks,
Rick



>
> Regards,
> Bin