[RFC,v2,0/3] Deduplicate RISCV cmpxchg.h and atomic.c macros

Message

Leonardo Bras Aug. 3, 2023, 5:13 a.m. UTC

I unified previous patchsets into a single one, since the work is related.

While studying riscv's cmpxchg.h file, I got really interested in
understanding how RISCV asm implemented the different versions of
{cmp,}xchg.

When I understood the pattern, it made sense for me to remove the
duplications and create macros to make it easier to understand what exactly
changes between the versions: Instruction sufixes & barriers.

Also, did the same kind of work on atomic.c.

Note to Guo Ren:
I did some further improvement after your previous reviews, so I ended
up afraid including your Reviewed-by before cheching if the changes are
ok for you. Please check it out again, I just removed some helper macros
that were not being used elsewhere in the kernel.

Thanks!
Leo


Changes since squashed cmpxchg:
- Unified with atomic.c patchset 
- Rebased on top of torvalds/master (thanks Andrea Parri!)
- Removed helper macros that were not being used elsewhere in the kernel.

Changes since (cmpxchg) RFCv3:
- Squashed the 6 original patches in 2: one for cmpxchg and one for xchg
https://lore.kernel.org/all/[e-mail]/

Changes since (cmpxchg) RFCv2:
- Fixed  macros that depend on having a local variable with a magic name
- Previous cast to (long) is now only applied on 4-bytes cmpxchg
https://lore.kernel.org/all/[e-mail]/

Changes since (cmpxchg) RFCv1:
- Fixed patch 4/6 suffix from 'w.aqrl' to '.w.aqrl', to avoid build error
https://lore.kernel.org/all/[e-mail]/


Leonardo Bras (3):
  riscv/cmpxchg: Deduplicate xchg() asm functions
  riscv/cmpxchg: Deduplicate cmpxchg() asm and macros
  riscv/atomic.h : Deduplicate arch_atomic.*

 arch/riscv/include/asm/atomic.h  | 164 ++++++++--------
 arch/riscv/include/asm/cmpxchg.h | 318 +++++--------------------------
 2 files changed, 123 insertions(+), 359 deletions(-)

Comments

Andrea Parri Aug. 3, 2023, 1:53 p.m. UTC | #1

On Thu, Aug 03, 2023 at 02:13:57AM -0300, Leonardo Bras wrote:
> I unified previous patchsets into a single one, since the work is related.
> 
> While studying riscv's cmpxchg.h file, I got really interested in
> understanding how RISCV asm implemented the different versions of
> {cmp,}xchg.
> 
> When I understood the pattern, it made sense for me to remove the
> duplications and create macros to make it easier to understand what exactly
> changes between the versions: Instruction sufixes & barriers.
> 
> Also, did the same kind of work on atomic.c.
> 
> Note to Guo Ren:
> I did some further improvement after your previous reviews, so I ended
> up afraid including your Reviewed-by before cheching if the changes are
> ok for you. Please check it out again, I just removed some helper macros
> that were not being used elsewhere in the kernel.
> 
> Thanks!
> Leo
> 
> 
> Changes since squashed cmpxchg:
> - Unified with atomic.c patchset 
> - Rebased on top of torvalds/master (thanks Andrea Parri!)
> - Removed helper macros that were not being used elsewhere in the kernel.
> 
> Changes since (cmpxchg) RFCv3:
> - Squashed the 6 original patches in 2: one for cmpxchg and one for xchg
> https://lore.kernel.org/all/[e-mail]/
> 
> Changes since (cmpxchg) RFCv2:
> - Fixed  macros that depend on having a local variable with a magic name
> - Previous cast to (long) is now only applied on 4-bytes cmpxchg
> https://lore.kernel.org/all/[e-mail]/
> 
> Changes since (cmpxchg) RFCv1:
> - Fixed patch 4/6 suffix from 'w.aqrl' to '.w.aqrl', to avoid build error
> https://lore.kernel.org/all/[e-mail]/
> 
> 
> Leonardo Bras (3):
>   riscv/cmpxchg: Deduplicate xchg() asm functions
>   riscv/cmpxchg: Deduplicate cmpxchg() asm and macros
>   riscv/atomic.h : Deduplicate arch_atomic.*
> 
>  arch/riscv/include/asm/atomic.h  | 164 ++++++++--------
>  arch/riscv/include/asm/cmpxchg.h | 318 +++++--------------------------
>  2 files changed, 123 insertions(+), 359 deletions(-)

LGTM.  For the series,

Reviewed-by: Andrea Parri <[e-mail]>

  Andrea

Guo Ren Aug. 4, 2023, 12:53 a.m. UTC | #2

On Thu, Aug 3, 2023 at 1:14 PM Leonardo Bras <[e-mail]> wrote:
>
> I unified previous patchsets into a single one, since the work is related.
>
> While studying riscv's cmpxchg.h file, I got really interested in
> understanding how RISCV asm implemented the different versions of
> {cmp,}xchg.
>
> When I understood the pattern, it made sense for me to remove the
> duplications and create macros to make it easier to understand what exactly
> changes between the versions: Instruction sufixes & barriers.
>
> Also, did the same kind of work on atomic.c.
>
> Note to Guo Ren:
> I did some further improvement after your previous reviews, so I ended
> up afraid including your Reviewed-by before cheching if the changes are
> ok for you. Please check it out again, I just removed some helper macros
> that were not being used elsewhere in the kernel.
I found this optimization has conflicts with the below patches:
https://lore.kernel.org/linux-riscv/[e-mail]/
https://lore.kernel.org/linux-riscv/[e-mail]/

If yours merged, how do we support the inline cmpxchg/xchg_small
function? It's very struggling to use macros to implement complex
functions.

Could you consider a more relaxed optimization in which we could
insert inline cmpxchg/xchg_small?

>
> Thanks!
> Leo
>
>
> Changes since squashed cmpxchg:
> - Unified with atomic.c patchset
> - Rebased on top of torvalds/master (thanks Andrea Parri!)
> - Removed helper macros that were not being used elsewhere in the kernel.
>
> Changes since (cmpxchg) RFCv3:
> - Squashed the 6 original patches in 2: one for cmpxchg and one for xchg
> https://lore.kernel.org/all/[e-mail]/
>
> Changes since (cmpxchg) RFCv2:
> - Fixed  macros that depend on having a local variable with a magic name
> - Previous cast to (long) is now only applied on 4-bytes cmpxchg
> https://lore.kernel.org/all/[e-mail]/
>
> Changes since (cmpxchg) RFCv1:
> - Fixed patch 4/6 suffix from 'w.aqrl' to '.w.aqrl', to avoid build error
> https://lore.kernel.org/all/[e-mail]/
>
>
> Leonardo Bras (3):
>   riscv/cmpxchg: Deduplicate xchg() asm functions
>   riscv/cmpxchg: Deduplicate cmpxchg() asm and macros
>   riscv/atomic.h : Deduplicate arch_atomic.*
>
>  arch/riscv/include/asm/atomic.h  | 164 ++++++++--------
>  arch/riscv/include/asm/cmpxchg.h | 318 +++++--------------------------
>  2 files changed, 123 insertions(+), 359 deletions(-)
>
> --
> 2.41.0
>

Leonardo Bras Aug. 4, 2023, 2:19 a.m. UTC | #3

On Thu, Aug 3, 2023 at 9:53 PM Guo Ren <[e-mail]> wrote:
>
> On Thu, Aug 3, 2023 at 1:14 PM Leonardo Bras <[e-mail]> wrote:
> >
> > I unified previous patchsets into a single one, since the work is related.
> >
> > While studying riscv's cmpxchg.h file, I got really interested in
> > understanding how RISCV asm implemented the different versions of
> > {cmp,}xchg.
> >
> > When I understood the pattern, it made sense for me to remove the
> > duplications and create macros to make it easier to understand what exactly
> > changes between the versions: Instruction sufixes & barriers.
> >
> > Also, did the same kind of work on atomic.c.
> >
> > Note to Guo Ren:
> > I did some further improvement after your previous reviews, so I ended
> > up afraid including your Reviewed-by before cheching if the changes are
> > ok for you. Please check it out again, I just removed some helper macros
> > that were not being used elsewhere in the kernel.
> I found this optimization has conflicts with the below patches:
> https://lore.kernel.org/linux-riscv/[e-mail]/
> https://lore.kernel.org/linux-riscv/[e-mail]/
>
> If yours merged, how do we support the inline cmpxchg/xchg_small
> function?

Oh, I actually introduced my series so I could introduce new xchg and
cmpxchg for size 1 and 2. Is that what your patches are about, right?

I was working on that yesterday, and decided to send the patchset
without them because I was still not sure enough.

About implementation strategy, I was introducing a new macros for xchg
& cmpxchg with asm which would work for both for size 1 & size 2, and
use the switch-case to create the mask and and_value.

You think that works enough?

> It's very struggling to use macros to implement complex
> functions.

I agree, but with this we can achieve more generic code, which makes
more clear what is the pattern for given function.

> Could you consider a more relaxed optimization in which we could
> insert inline cmpxchg/xchg_small?

What about this: I finish the patches I have been working with
(cmpxchg & xchg for sizes 1 and 2), and if they are fine we expand
this patchset with them.  If not, I try relaxing them a little so we
can merge with your set.

Does that work for you?

Best regards,
Leo


>
> >
> > Thanks!
> > Leo
> >
> >
> > Changes since squashed cmpxchg:
> > - Unified with atomic.c patchset
> > - Rebased on top of torvalds/master (thanks Andrea Parri!)
> > - Removed helper macros that were not being used elsewhere in the kernel.
> >
> > Changes since (cmpxchg) RFCv3:
> > - Squashed the 6 original patches in 2: one for cmpxchg and one for xchg
> > https://lore.kernel.org/all/[e-mail]/
> >
> > Changes since (cmpxchg) RFCv2:
> > - Fixed  macros that depend on having a local variable with a magic name
> > - Previous cast to (long) is now only applied on 4-bytes cmpxchg
> > https://lore.kernel.org/all/[e-mail]/
> >
> > Changes since (cmpxchg) RFCv1:
> > - Fixed patch 4/6 suffix from 'w.aqrl' to '.w.aqrl', to avoid build error
> > https://lore.kernel.org/all/[e-mail]/
> >
> >
> > Leonardo Bras (3):
> >   riscv/cmpxchg: Deduplicate xchg() asm functions
> >   riscv/cmpxchg: Deduplicate cmpxchg() asm and macros
> >   riscv/atomic.h : Deduplicate arch_atomic.*
> >
> >  arch/riscv/include/asm/atomic.h  | 164 ++++++++--------
> >  arch/riscv/include/asm/cmpxchg.h | 318 +++++--------------------------
> >  2 files changed, 123 insertions(+), 359 deletions(-)
> >
> > --
> > 2.41.0
> >
>
>
> --
> Best Regards
>  Guo Ren
>

Leonardo Bras Aug. 4, 2023, 2:20 a.m. UTC | #4

On Thu, Aug 3, 2023 at 10:53 AM Andrea Parri <[e-mail]> wrote:
>
> On Thu, Aug 03, 2023 at 02:13:57AM -0300, Leonardo Bras wrote:
> > I unified previous patchsets into a single one, since the work is related.
> >
> > While studying riscv's cmpxchg.h file, I got really interested in
> > understanding how RISCV asm implemented the different versions of
> > {cmp,}xchg.
> >
> > When I understood the pattern, it made sense for me to remove the
> > duplications and create macros to make it easier to understand what exactly
> > changes between the versions: Instruction sufixes & barriers.
> >
> > Also, did the same kind of work on atomic.c.
> >
> > Note to Guo Ren:
> > I did some further improvement after your previous reviews, so I ended
> > up afraid including your Reviewed-by before cheching if the changes are
> > ok for you. Please check it out again, I just removed some helper macros
> > that were not being used elsewhere in the kernel.
> >
> > Thanks!
> > Leo
> >
> >
> > Changes since squashed cmpxchg:
> > - Unified with atomic.c patchset
> > - Rebased on top of torvalds/master (thanks Andrea Parri!)
> > - Removed helper macros that were not being used elsewhere in the kernel.
> >
> > Changes since (cmpxchg) RFCv3:
> > - Squashed the 6 original patches in 2: one for cmpxchg and one for xchg
> > https://lore.kernel.org/all/[e-mail]/
> >
> > Changes since (cmpxchg) RFCv2:
> > - Fixed  macros that depend on having a local variable with a magic name
> > - Previous cast to (long) is now only applied on 4-bytes cmpxchg
> > https://lore.kernel.org/all/[e-mail]/
> >
> > Changes since (cmpxchg) RFCv1:
> > - Fixed patch 4/6 suffix from 'w.aqrl' to '.w.aqrl', to avoid build error
> > https://lore.kernel.org/all/[e-mail]/
> >
> >
> > Leonardo Bras (3):
> >   riscv/cmpxchg: Deduplicate xchg() asm functions
> >   riscv/cmpxchg: Deduplicate cmpxchg() asm and macros
> >   riscv/atomic.h : Deduplicate arch_atomic.*
> >
> >  arch/riscv/include/asm/atomic.h  | 164 ++++++++--------
> >  arch/riscv/include/asm/cmpxchg.h | 318 +++++--------------------------
> >  2 files changed, 123 insertions(+), 359 deletions(-)
>
> LGTM.  For the series,
>
> Reviewed-by: Andrea Parri <[e-mail]>
>
>   Andrea

Thanks Andrea!

>

Guo Ren Aug. 4, 2023, 2:29 a.m. UTC | #5

On Fri, Aug 4, 2023 at 10:20 AM Leonardo Bras Soares Passos
<[e-mail]> wrote:
>
> On Thu, Aug 3, 2023 at 9:53 PM Guo Ren <[e-mail]> wrote:
> >
> > On Thu, Aug 3, 2023 at 1:14 PM Leonardo Bras <[e-mail]> wrote:
> > >
> > > I unified previous patchsets into a single one, since the work is related.
> > >
> > > While studying riscv's cmpxchg.h file, I got really interested in
> > > understanding how RISCV asm implemented the different versions of
> > > {cmp,}xchg.
> > >
> > > When I understood the pattern, it made sense for me to remove the
> > > duplications and create macros to make it easier to understand what exactly
> > > changes between the versions: Instruction sufixes & barriers.
> > >
> > > Also, did the same kind of work on atomic.c.
> > >
> > > Note to Guo Ren:
> > > I did some further improvement after your previous reviews, so I ended
> > > up afraid including your Reviewed-by before cheching if the changes are
> > > ok for you. Please check it out again, I just removed some helper macros
> > > that were not being used elsewhere in the kernel.
> > I found this optimization has conflicts with the below patches:
> > https://lore.kernel.org/linux-riscv/[e-mail]/
> > https://lore.kernel.org/linux-riscv/[e-mail]/
> >
> > If yours merged, how do we support the inline cmpxchg/xchg_small
> > function?
>
> Oh, I actually introduced my series so I could introduce new xchg and
> cmpxchg for size 1 and 2. Is that what your patches are about, right?
>
> I was working on that yesterday, and decided to send the patchset
> without them because I was still not sure enough.
>
> About implementation strategy, I was introducing a new macros for xchg
> & cmpxchg with asm which would work for both for size 1 & size 2, and
> use the switch-case to create the mask and and_value.
>
> You think that works enough?
Good, go ahead.

>
> > It's very struggling to use macros to implement complex
> > functions.
>
> I agree, but with this we can achieve more generic code, which makes
> more clear what is the pattern for given function.
>
> > Could you consider a more relaxed optimization in which we could
> > insert inline cmpxchg/xchg_small?
>
> What about this: I finish the patches I have been working with
> (cmpxchg & xchg for sizes 1 and 2), and if they are fine we expand
> this patchset with them.  If not, I try relaxing them a little so we
> can merge with your set.
>
> Does that work for you?
Great, you could provide cmpxchg & xchg for sizes 1 and 2, then my
patch series would base on yours. After tested, I would give you
Tested-by.
>
> Best regards,
> Leo
>
>
> >
> > >
> > > Thanks!
> > > Leo
> > >
> > >
> > > Changes since squashed cmpxchg:
> > > - Unified with atomic.c patchset
> > > - Rebased on top of torvalds/master (thanks Andrea Parri!)
> > > - Removed helper macros that were not being used elsewhere in the kernel.
> > >
> > > Changes since (cmpxchg) RFCv3:
> > > - Squashed the 6 original patches in 2: one for cmpxchg and one for xchg
> > > https://lore.kernel.org/all/[e-mail]/
> > >
> > > Changes since (cmpxchg) RFCv2:
> > > - Fixed  macros that depend on having a local variable with a magic name
> > > - Previous cast to (long) is now only applied on 4-bytes cmpxchg
> > > https://lore.kernel.org/all/[e-mail]/
> > >
> > > Changes since (cmpxchg) RFCv1:
> > > - Fixed patch 4/6 suffix from 'w.aqrl' to '.w.aqrl', to avoid build error
> > > https://lore.kernel.org/all/[e-mail]/
> > >
> > >
> > > Leonardo Bras (3):
> > >   riscv/cmpxchg: Deduplicate xchg() asm functions
> > >   riscv/cmpxchg: Deduplicate cmpxchg() asm and macros
> > >   riscv/atomic.h : Deduplicate arch_atomic.*
> > >
> > >  arch/riscv/include/asm/atomic.h  | 164 ++++++++--------
> > >  arch/riscv/include/asm/cmpxchg.h | 318 +++++--------------------------
> > >  2 files changed, 123 insertions(+), 359 deletions(-)
> > >
> > > --
> > > 2.41.0
> > >
> >
> >
> > --
> > Best Regards
> >  Guo Ren
> >
>

Leonardo Bras Aug. 4, 2023, 8:05 a.m. UTC | #6

On Thu, Aug 3, 2023 at 11:29 PM Guo Ren <[e-mail]> wrote:
>
> On Fri, Aug 4, 2023 at 10:20 AM Leonardo Bras Soares Passos
> <[e-mail]> wrote:
> >
> > On Thu, Aug 3, 2023 at 9:53 PM Guo Ren <[e-mail]> wrote:
> > >
> > > On Thu, Aug 3, 2023 at 1:14 PM Leonardo Bras <[e-mail]> wrote:
> > > >
> > > > I unified previous patchsets into a single one, since the work is related.
> > > >
> > > > While studying riscv's cmpxchg.h file, I got really interested in
> > > > understanding how RISCV asm implemented the different versions of
> > > > {cmp,}xchg.
> > > >
> > > > When I understood the pattern, it made sense for me to remove the
> > > > duplications and create macros to make it easier to understand what exactly
> > > > changes between the versions: Instruction sufixes & barriers.
> > > >
> > > > Also, did the same kind of work on atomic.c.
> > > >
> > > > Note to Guo Ren:
> > > > I did some further improvement after your previous reviews, so I ended
> > > > up afraid including your Reviewed-by before cheching if the changes are
> > > > ok for you. Please check it out again, I just removed some helper macros
> > > > that were not being used elsewhere in the kernel.
> > > I found this optimization has conflicts with the below patches:
> > > https://lore.kernel.org/linux-riscv/[e-mail]/
> > > https://lore.kernel.org/linux-riscv/[e-mail]/
> > >
> > > If yours merged, how do we support the inline cmpxchg/xchg_small
> > > function?
> >
> > Oh, I actually introduced my series so I could introduce new xchg and
> > cmpxchg for size 1 and 2. Is that what your patches are about, right?
> >
> > I was working on that yesterday, and decided to send the patchset
> > without them because I was still not sure enough.
> >
> > About implementation strategy, I was introducing a new macros for xchg
> > & cmpxchg with asm which would work for both for size 1 & size 2, and
> > use the switch-case to create the mask and and_value.
> >
> > You think that works enough?
> Good, go ahead.
>
> >
> > > It's very struggling to use macros to implement complex
> > > functions.
> >
> > I agree, but with this we can achieve more generic code, which makes
> > more clear what is the pattern for given function.
> >
> > > Could you consider a more relaxed optimization in which we could
> > > insert inline cmpxchg/xchg_small?
> >
> > What about this: I finish the patches I have been working with
> > (cmpxchg & xchg for sizes 1 and 2), and if they are fine we expand
> > this patchset with them.  If not, I try relaxing them a little so we
> > can merge with your set.
> >
> > Does that work for you?
> Great, you could provide cmpxchg & xchg for sizes 1 and 2, then my
> patch series would base on yours. After tested, I would give you
> Tested-by.

Awesome! Thanks!

I will send it shortly, just compile-testing the kernel.

> >
> > Best regards,
> > Leo
> >
> >
> > >
> > > >
> > > > Thanks!
> > > > Leo
> > > >
> > > >
> > > > Changes since squashed cmpxchg:
> > > > - Unified with atomic.c patchset
> > > > - Rebased on top of torvalds/master (thanks Andrea Parri!)
> > > > - Removed helper macros that were not being used elsewhere in the kernel.
> > > >
> > > > Changes since (cmpxchg) RFCv3:
> > > > - Squashed the 6 original patches in 2: one for cmpxchg and one for xchg
> > > > https://lore.kernel.org/all/[e-mail]/
> > > >
> > > > Changes since (cmpxchg) RFCv2:
> > > > - Fixed  macros that depend on having a local variable with a magic name
> > > > - Previous cast to (long) is now only applied on 4-bytes cmpxchg
> > > > https://lore.kernel.org/all/[e-mail]/
> > > >
> > > > Changes since (cmpxchg) RFCv1:
> > > > - Fixed patch 4/6 suffix from 'w.aqrl' to '.w.aqrl', to avoid build error
> > > > https://lore.kernel.org/all/[e-mail]/
> > > >
> > > >
> > > > Leonardo Bras (3):
> > > >   riscv/cmpxchg: Deduplicate xchg() asm functions
> > > >   riscv/cmpxchg: Deduplicate cmpxchg() asm and macros
> > > >   riscv/atomic.h : Deduplicate arch_atomic.*
> > > >
> > > >  arch/riscv/include/asm/atomic.h  | 164 ++++++++--------
> > > >  arch/riscv/include/asm/cmpxchg.h | 318 +++++--------------------------
> > > >  2 files changed, 123 insertions(+), 359 deletions(-)
> > > >
> > > > --
> > > > 2.41.0
> > > >
> > >
> > >
> > > --
> > > Best Regards
> > >  Guo Ren
> > >
> >
>
>
> --
> Best Regards
>  Guo Ren
>

Leonardo Bras Aug. 4, 2023, 8:55 a.m. UTC | #7

On Fri, Aug 4, 2023 at 5:05 AM Leonardo Bras Soares Passos
<[e-mail]> wrote:
>
> On Thu, Aug 3, 2023 at 11:29 PM Guo Ren <[e-mail]> wrote:
> >
> > On Fri, Aug 4, 2023 at 10:20 AM Leonardo Bras Soares Passos
> > <[e-mail]> wrote:
> > >
> > > On Thu, Aug 3, 2023 at 9:53 PM Guo Ren <[e-mail]> wrote:
> > > >
> > > > On Thu, Aug 3, 2023 at 1:14 PM Leonardo Bras <[e-mail]> wrote:
> > > > >
> > > > > I unified previous patchsets into a single one, since the work is related.
> > > > >
> > > > > While studying riscv's cmpxchg.h file, I got really interested in
> > > > > understanding how RISCV asm implemented the different versions of
> > > > > {cmp,}xchg.
> > > > >
> > > > > When I understood the pattern, it made sense for me to remove the
> > > > > duplications and create macros to make it easier to understand what exactly
> > > > > changes between the versions: Instruction sufixes & barriers.
> > > > >
> > > > > Also, did the same kind of work on atomic.c.
> > > > >
> > > > > Note to Guo Ren:
> > > > > I did some further improvement after your previous reviews, so I ended
> > > > > up afraid including your Reviewed-by before cheching if the changes are
> > > > > ok for you. Please check it out again, I just removed some helper macros
> > > > > that were not being used elsewhere in the kernel.
> > > > I found this optimization has conflicts with the below patches:
> > > > https://lore.kernel.org/linux-riscv/[e-mail]/
> > > > https://lore.kernel.org/linux-riscv/[e-mail]/
> > > >
> > > > If yours merged, how do we support the inline cmpxchg/xchg_small
> > > > function?
> > >
> > > Oh, I actually introduced my series so I could introduce new xchg and
> > > cmpxchg for size 1 and 2. Is that what your patches are about, right?
> > >
> > > I was working on that yesterday, and decided to send the patchset
> > > without them because I was still not sure enough.
> > >
> > > About implementation strategy, I was introducing a new macros for xchg
> > > & cmpxchg with asm which would work for both for size 1 & size 2, and
> > > use the switch-case to create the mask and and_value.
> > >
> > > You think that works enough?
> > Good, go ahead.
> >
> > >
> > > > It's very struggling to use macros to implement complex
> > > > functions.
> > >
> > > I agree, but with this we can achieve more generic code, which makes
> > > more clear what is the pattern for given function.
> > >
> > > > Could you consider a more relaxed optimization in which we could
> > > > insert inline cmpxchg/xchg_small?
> > >
> > > What about this: I finish the patches I have been working with
> > > (cmpxchg & xchg for sizes 1 and 2), and if they are fine we expand
> > > this patchset with them.  If not, I try relaxing them a little so we
> > > can merge with your set.
> > >
> > > Does that work for you?
> > Great, you could provide cmpxchg & xchg for sizes 1 and 2, then my
> > patch series would base on yours. After tested, I would give you
> > Tested-by.
>
> Awesome! Thanks!
>
> I will send it shortly, just compile-testing the kernel.
>

v3:
https://patchwork.kernel.org/project/linux-riscv/list/?series=772986&state=%2A&archive=both

> > >
> > > Best regards,
> > > Leo
> > >
> > >
> > > >
> > > > >
> > > > > Thanks!
> > > > > Leo
> > > > >
> > > > >
> > > > > Changes since squashed cmpxchg:
> > > > > - Unified with atomic.c patchset
> > > > > - Rebased on top of torvalds/master (thanks Andrea Parri!)
> > > > > - Removed helper macros that were not being used elsewhere in the kernel.
> > > > >
> > > > > Changes since (cmpxchg) RFCv3:
> > > > > - Squashed the 6 original patches in 2: one for cmpxchg and one for xchg
> > > > > https://lore.kernel.org/all/[e-mail]/
> > > > >
> > > > > Changes since (cmpxchg) RFCv2:
> > > > > - Fixed  macros that depend on having a local variable with a magic name
> > > > > - Previous cast to (long) is now only applied on 4-bytes cmpxchg
> > > > > https://lore.kernel.org/all/[e-mail]/
> > > > >
> > > > > Changes since (cmpxchg) RFCv1:
> > > > > - Fixed patch 4/6 suffix from 'w.aqrl' to '.w.aqrl', to avoid build error
> > > > > https://lore.kernel.org/all/[e-mail]/
> > > > >
> > > > >
> > > > > Leonardo Bras (3):
> > > > >   riscv/cmpxchg: Deduplicate xchg() asm functions
> > > > >   riscv/cmpxchg: Deduplicate cmpxchg() asm and macros
> > > > >   riscv/atomic.h : Deduplicate arch_atomic.*
> > > > >
> > > > >  arch/riscv/include/asm/atomic.h  | 164 ++++++++--------
> > > > >  arch/riscv/include/asm/cmpxchg.h | 318 +++++--------------------------
> > > > >  2 files changed, 123 insertions(+), 359 deletions(-)
> > > > >
> > > > > --
> > > > > 2.41.0
> > > > >
> > > >
> > > >
> > > > --
> > > > Best Regards
> > > >  Guo Ren
> > > >
> > >
> >
> >
> > --
> > Best Regards
> >  Guo Ren
> >