[PATCH] locking/atomics: Simplify the op definitions in atomic.h some more
Andrea Parri
andrea.parri at amarulasolutions.com
Mon May 7 02:54:03 PDT 2018
On Sun, May 06, 2018 at 04:57:27PM +0200, Ingo Molnar wrote:
>
> * Andrea Parri <andrea.parri at amarulasolutions.com> wrote:
>
> > Hi Ingo,
> >
> > > From 5affbf7e91901143f84f1b2ca64f4afe70e210fd Mon Sep 17 00:00:00 2001
> > > From: Ingo Molnar <mingo at kernel.org>
> > > Date: Sat, 5 May 2018 10:23:23 +0200
> > > Subject: [PATCH] locking/atomics: Simplify the op definitions in atomic.h some more
> > >
> > > Before:
> > >
> > > #ifndef atomic_fetch_dec_relaxed
> > > # ifndef atomic_fetch_dec
> > > # define atomic_fetch_dec(v) atomic_fetch_sub(1, (v))
> > > # define atomic_fetch_dec_relaxed(v) atomic_fetch_sub_relaxed(1, (v))
> > > # define atomic_fetch_dec_acquire(v) atomic_fetch_sub_acquire(1, (v))
> > > # define atomic_fetch_dec_release(v) atomic_fetch_sub_release(1, (v))
> > > # else
> > > # define atomic_fetch_dec_relaxed atomic_fetch_dec
> > > # define atomic_fetch_dec_acquire atomic_fetch_dec
> > > # define atomic_fetch_dec_release atomic_fetch_dec
> > > # endif
> > > #else
> > > # ifndef atomic_fetch_dec_acquire
> > > # define atomic_fetch_dec_acquire(...) __atomic_op_acquire(atomic_fetch_dec, __VA_ARGS__)
> > > # endif
> > > # ifndef atomic_fetch_dec_release
> > > # define atomic_fetch_dec_release(...) __atomic_op_release(atomic_fetch_dec, __VA_ARGS__)
> > > # endif
> > > # ifndef atomic_fetch_dec
> > > # define atomic_fetch_dec(...) __atomic_op_fence(atomic_fetch_dec, __VA_ARGS__)
> > > # endif
> > > #endif
> > >
> > > After:
> > >
> > > #ifndef atomic_fetch_dec_relaxed
> > > # ifndef atomic_fetch_dec
> > > # define atomic_fetch_dec(v) atomic_fetch_sub(1, (v))
> > > # define atomic_fetch_dec_relaxed(v) atomic_fetch_sub_relaxed(1, (v))
> > > # define atomic_fetch_dec_acquire(v) atomic_fetch_sub_acquire(1, (v))
> > > # define atomic_fetch_dec_release(v) atomic_fetch_sub_release(1, (v))
> > > # else
> > > # define atomic_fetch_dec_relaxed atomic_fetch_dec
> > > # define atomic_fetch_dec_acquire atomic_fetch_dec
> > > # define atomic_fetch_dec_release atomic_fetch_dec
> > > # endif
> > > #else
> > > # ifndef atomic_fetch_dec
> > > # define atomic_fetch_dec(...) __atomic_op_fence(atomic_fetch_dec, __VA_ARGS__)
> > > # define atomic_fetch_dec_acquire(...) __atomic_op_acquire(atomic_fetch_dec, __VA_ARGS__)
> > > # define atomic_fetch_dec_release(...) __atomic_op_release(atomic_fetch_dec, __VA_ARGS__)
> > > # endif
> > > #endif
> > >
> > > The idea is that because we already group these APIs by certain defines
> > > such as atomic_fetch_dec_relaxed and atomic_fetch_dec in the primary
> > > branches - we can do the same in the secondary branch as well.
> > >
> > > ( Also remove some unnecessarily duplicate comments, as the API
> > > group defines are now pretty much self-documenting. )
> > >
> > > No change in functionality.
> > >
> > > Cc: Peter Zijlstra <peterz at infradead.org>
> > > Cc: Linus Torvalds <torvalds at linux-foundation.org>
> > > Cc: Andrew Morton <akpm at linux-foundation.org>
> > > Cc: Thomas Gleixner <tglx at linutronix.de>
> > > Cc: Paul E. McKenney <paulmck at linux.vnet.ibm.com>
> > > Cc: Will Deacon <will.deacon at arm.com>
> > > Cc: linux-kernel at vger.kernel.org
> > > Signed-off-by: Ingo Molnar <mingo at kernel.org>
> >
> > This breaks compilation on RISC-V. (For some of its atomics, the arch
> > currently defines the _relaxed and the full variants and it relies on
> > the generic definitions for the _acquire and the _release variants.)
>
> I don't have cross-compilation for RISC-V, which is a relatively new arch.
> (Is there any RISC-V set of cross-compilation tools on kernel.org somewhere?)
I'm using the toolchain from:
https://riscv.org/software-tools/
(adding Palmer and Albert in Cc:)
>
> Could you please send a patch that defines those variants against Linus's tree,
> like the PowerPC patch that does something similar:
>
> 0476a632cb3a: locking/atomics/powerpc: Move cmpxchg helpers to asm/cmpxchg.h and define the full set of cmpxchg APIs
>
> ?
Yes, please see below for a first RFC.
(BTW, get_maintainer.pl says that that patch missed Benjamin, Paul, Michael
and linuxppc-dev at lists.ozlabs.org: FWIW, I'm Cc-ing the maintainers here.)
Andrea
>From 411f05a44e0b53a435331b977ff864fba7501a95 Mon Sep 17 00:00:00 2001
From: Andrea Parri <andrea.parri at amarulasolutions.com>
Date: Mon, 7 May 2018 10:59:20 +0200
Subject: [RFC PATCH] riscv/atomic: Defines _acquire/_release variants
In preparation for Ingo's renovation of the generic atomic.h header [1],
define the _acquire/_release variants in the arch's header.
No change in code generation.
[1] http://lkml.kernel.org/r/20180505081100.nsyrqrpzq2vd27bk@gmail.com
http://lkml.kernel.org/r/20180505083635.622xmcvb42dw5xxh@gmail.com
Suggested-by: Ingo Molnar <mingo at kernel.org>
Signed-off-by: Andrea Parri <andrea.parri at amarulasolutions.com>
Cc: Palmer Dabbelt <palmer at sifive.com>
Cc: Albert Ou <albert at sifive.com>
Cc: Will Deacon <will.deacon at arm.com>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Boqun Feng <boqun.feng at gmail.com>
Cc: linux-riscv at lists.infradead.org
---
arch/riscv/include/asm/atomic.h | 88 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 88 insertions(+)
diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h
index 855115ace98c8..7cbd8033dfb5d 100644
--- a/arch/riscv/include/asm/atomic.h
+++ b/arch/riscv/include/asm/atomic.h
@@ -153,22 +153,54 @@ ATOMIC_OPS(sub, add, +, -i)
#define atomic_add_return_relaxed atomic_add_return_relaxed
#define atomic_sub_return_relaxed atomic_sub_return_relaxed
+#define atomic_add_return_acquire(...) \
+ __atomic_op_acquire(atomic_add_return, __VA_ARGS__)
+#define atomic_sub_return_acquire(...) \
+ __atomic_op_acquire(atomic_sub_return, __VA_ARGS__)
+#define atomic_add_return_release(...) \
+ __atomic_op_release(atomic_add_return, __VA_ARGS__)
+#define atomic_sub_return_release(...) \
+ __atomic_op_release(atomic_sub_return, __VA_ARGS__)
#define atomic_add_return atomic_add_return
#define atomic_sub_return atomic_sub_return
#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
+#define atomic_fetch_add_acquire(...) \
+ __atomic_op_acquire(atomic_fetch_add, __VA_ARGS__)
+#define atomic_fetch_sub_acquire(...) \
+ __atomic_op_acquire(atomic_fetch_sub, __VA_ARGS__)
+#define atomic_fetch_add_release(...) \
+ __atomic_op_release(atomic_fetch_add, __VA_ARGS__)
+#define atomic_fetch_sub_release(...) \
+ __atomic_op_release(atomic_fetch_sub, __VA_ARGS__)
#define atomic_fetch_add atomic_fetch_add
#define atomic_fetch_sub atomic_fetch_sub
#ifndef CONFIG_GENERIC_ATOMIC64
#define atomic64_add_return_relaxed atomic64_add_return_relaxed
#define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
+#define atomic64_add_return_acquire(...) \
+ __atomic_op_acquire(atomic64_add_return, __VA_ARGS__)
+#define atomic64_sub_return_acquire(...) \
+ __atomic_op_acquire(atomic64_sub_return, __VA_ARGS__)
+#define atomic64_add_return_release(...) \
+ __atomic_op_release(atomic64_add_return, __VA_ARGS__)
+#define atomic64_sub_return_release(...) \
+ __atomic_op_release(atomic64_sub_return, __VA_ARGS__)
#define atomic64_add_return atomic64_add_return
#define atomic64_sub_return atomic64_sub_return
#define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
#define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
+#define atomic64_fetch_add_acquire(...) \
+ __atomic_op_acquire(atomic64_fetch_add, __VA_ARGS__)
+#define atomic64_fetch_sub_acquire(...) \
+ __atomic_op_acquire(atomic64_fetch_sub, __VA_ARGS__)
+#define atomic64_fetch_add_release(...) \
+ __atomic_op_release(atomic64_fetch_add, __VA_ARGS__)
+#define atomic64_fetch_sub_release(...) \
+ __atomic_op_release(atomic64_fetch_sub, __VA_ARGS__)
#define atomic64_fetch_add atomic64_fetch_add
#define atomic64_fetch_sub atomic64_fetch_sub
#endif
@@ -191,6 +223,18 @@ ATOMIC_OPS(xor, xor, i)
#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
+#define atomic_fetch_and_acquire(...) \
+ __atomic_op_acquire(atomic_fetch_and, __VA_ARGS__)
+#define atomic_fetch_or_acquire(...) \
+ __atomic_op_acquire(atomic_fetch_or, __VA_ARGS__)
+#define atomic_fetch_xor_acquire(...) \
+ __atomic_op_acquire(atomic_fetch_xor, __VA_ARGS__)
+#define atomic_fetch_and_release(...) \
+ __atomic_op_release(atomic_fetch_and, __VA_ARGS__)
+#define atomic_fetch_or_release(...) \
+ __atomic_op_release(atomic_fetch_or, __VA_ARGS__)
+#define atomic_fetch_xor_release(...) \
+ __atomic_op_release(atomic_fetch_xor, __VA_ARGS__)
#define atomic_fetch_and atomic_fetch_and
#define atomic_fetch_or atomic_fetch_or
#define atomic_fetch_xor atomic_fetch_xor
@@ -199,6 +243,18 @@ ATOMIC_OPS(xor, xor, i)
#define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
#define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
#define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
+#define atomic64_fetch_and_acquire(...) \
+ __atomic_op_acquire(atomic64_fetch_and, __VA_ARGS__)
+#define atomic64_fetch_or_acquire(...) \
+ __atomic_op_acquire(atomic64_fetch_or, __VA_ARGS__)
+#define atomic64_fetch_xor_acquire(...) \
+ __atomic_op_acquire(atomic64_fetch_xor, __VA_ARGS__)
+#define atomic64_fetch_and_release(...) \
+ __atomic_op_release(atomic64_fetch_and, __VA_ARGS__)
+#define atomic64_fetch_or_release(...) \
+ __atomic_op_release(atomic64_fetch_or, __VA_ARGS__)
+#define atomic64_fetch_xor_release(...) \
+ __atomic_op_release(atomic64_fetch_xor, __VA_ARGS__)
#define atomic64_fetch_and atomic64_fetch_and
#define atomic64_fetch_or atomic64_fetch_or
#define atomic64_fetch_xor atomic64_fetch_xor
@@ -290,22 +346,54 @@ ATOMIC_OPS(dec, add, +, -1)
#define atomic_inc_return_relaxed atomic_inc_return_relaxed
#define atomic_dec_return_relaxed atomic_dec_return_relaxed
+#define atomic_inc_return_acquire(...) \
+ __atomic_op_acquire(atomic_inc_return, __VA_ARGS__)
+#define atomic_dec_return_acquire(...) \
+ __atomic_op_acquire(atomic_dec_return, __VA_ARGS__)
+#define atomic_inc_return_release(...) \
+ __atomic_op_release(atomic_inc_return, __VA_ARGS__)
+#define atomic_dec_return_release(...) \
+ __atomic_op_release(atomic_dec_return, __VA_ARGS__)
#define atomic_inc_return atomic_inc_return
#define atomic_dec_return atomic_dec_return
#define atomic_fetch_inc_relaxed atomic_fetch_inc_relaxed
#define atomic_fetch_dec_relaxed atomic_fetch_dec_relaxed
+#define atomic_fetch_inc_acquire(...) \
+ __atomic_op_acquire(atomic_fetch_inc, __VA_ARGS__)
+#define atomic_fetch_dec_acquire(...) \
+ __atomic_op_acquire(atomic_fetch_dec, __VA_ARGS__)
+#define atomic_fetch_inc_release(...) \
+ __atomic_op_release(atomic_fetch_inc, __VA_ARGS__)
+#define atomic_fetch_dec_release(...) \
+ __atomic_op_release(atomic_fetch_dec, __VA_ARGS__)
#define atomic_fetch_inc atomic_fetch_inc
#define atomic_fetch_dec atomic_fetch_dec
#ifndef CONFIG_GENERIC_ATOMIC64
#define atomic64_inc_return_relaxed atomic64_inc_return_relaxed
#define atomic64_dec_return_relaxed atomic64_dec_return_relaxed
+#define atomic64_inc_return_acquire(...) \
+ __atomic_op_acquire(atomic64_inc_return, __VA_ARGS__)
+#define atomic64_dec_return_acquire(...) \
+ __atomic_op_acquire(atomic64_dec_return, __VA_ARGS__)
+#define atomic64_inc_return_release(...) \
+ __atomic_op_release(atomic64_inc_return, __VA_ARGS__)
+#define atomic64_dec_return_release(...) \
+ __atomic_op_release(atomic64_dec_return, __VA_ARGS__)
#define atomic64_inc_return atomic64_inc_return
#define atomic64_dec_return atomic64_dec_return
#define atomic64_fetch_inc_relaxed atomic64_fetch_inc_relaxed
#define atomic64_fetch_dec_relaxed atomic64_fetch_dec_relaxed
+#define atomic64_fetch_inc_acquire(...) \
+ __atomic_op_acquire(atomic64_fetch_inc, __VA_ARGS__)
+#define atomic64_fetch_dec_acquire(...) \
+ __atomic_op_acquire(atomic64_fetch_dec, __VA_ARGS__)
+#define atomic64_fetch_inc_release(...) \
+ __atomic_op_release(atomic64_fetch_inc, __VA_ARGS__)
+#define atomic64_fetch_dec_release(...) \
+ __atomic_op_release(atomic64_fetch_dec, __VA_ARGS__)
#define atomic64_fetch_inc atomic64_fetch_inc
#define atomic64_fetch_dec atomic64_fetch_dec
#endif
--
2.7.4
>
> ... and I'll integrate it into the proper place to make it all bisectable, etc.
>
> Thanks,
>
> Ingo
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