From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: lkml <linux-kernel@vger.kernel.org>, <arc-linux-dev@synopsys.com>,
Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: [PATCH 2/6] ARC: refactor atomic inline asm operands with symbolic names
Date: Mon, 3 Aug 2015 15:33:04 +0530 [thread overview]
Message-ID: <1438596188-10875-3-git-send-email-vgupta@synopsys.com> (raw)
In-Reply-To: <1438596188-10875-1-git-send-email-vgupta@synopsys.com>
This reduces the diff in forth-coming patches and also helps understand
better the incremental changes to inline asm.
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
arch/arc/include/asm/atomic.h | 32 +++++++++++++++++---------------
1 file changed, 17 insertions(+), 15 deletions(-)
diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h
index 20b7dc17979e..3dd36c1efee1 100644
--- a/arch/arc/include/asm/atomic.h
+++ b/arch/arc/include/asm/atomic.h
@@ -26,22 +26,23 @@
#define ATOMIC_OP(op, c_op, asm_op) \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
- unsigned int temp; \
+ unsigned int val; \
\
__asm__ __volatile__( \
- "1: llock %0, [%1] \n" \
- " " #asm_op " %0, %0, %2 \n" \
- " scond %0, [%1] \n" \
- " bnz 1b \n" \
- : "=&r"(temp) /* Early clobber, to prevent reg reuse */ \
- : "r"(&v->counter), "ir"(i) \
+ "1: llock %[val], [%[ctr]] \n" \
+ " " #asm_op " %[val], %[val], %[i] \n" \
+ " scond %[val], [%[ctr]] \n" \
+ " bnz 1b \n" \
+ : [val] "=&r" (val) /* Early clobber to prevent reg reuse */ \
+ : [ctr] "r" (&v->counter), /* Not "m": llock only supports reg direct addr mode */ \
+ [i] "ir" (i) \
: "cc"); \
} \
#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
static inline int atomic_##op##_return(int i, atomic_t *v) \
{ \
- unsigned int temp; \
+ unsigned int val; \
\
/* \
* Explicit full memory barrier needed before/after as \
@@ -50,17 +51,18 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \
smp_mb(); \
\
__asm__ __volatile__( \
- "1: llock %0, [%1] \n" \
- " " #asm_op " %0, %0, %2 \n" \
- " scond %0, [%1] \n" \
- " bnz 1b \n" \
- : "=&r"(temp) \
- : "r"(&v->counter), "ir"(i) \
+ "1: llock %[val], [%[ctr]] \n" \
+ " " #asm_op " %[val], %[val], %[i] \n" \
+ " scond %[val], [%[ctr]] \n" \
+ " bnz 1b \n" \
+ : [val] "=&r" (val) \
+ : [ctr] "r" (&v->counter), \
+ [i] "ir" (i) \
: "cc"); \
\
smp_mb(); \
\
- return temp; \
+ return val; \
}
#else /* !CONFIG_ARC_HAS_LLSC */
--
1.9.1
next prev parent reply other threads:[~2015-08-03 10:04 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-03 10:03 [PATCH 0/6] ARC: spinlocks/atomics rework Vineet Gupta
2015-08-03 10:03 ` [PATCH 1/6] Revert "ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock" Vineet Gupta
2015-08-03 10:03 ` Vineet Gupta [this message]
2015-08-03 10:03 ` [PATCH 3/6] ARC: LLOCK/SCOND based spin_lock Vineet Gupta
2015-08-03 11:29 ` Peter Zijlstra
2015-08-03 11:44 ` Vineet Gupta
2015-08-03 10:03 ` [PATCH 4/6] ARC: LLOCK/SCOND based rwlock Vineet Gupta
2015-08-03 11:33 ` Peter Zijlstra
2015-08-03 11:51 ` Vineet Gupta
2015-08-03 10:03 ` [PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff Vineet Gupta
2015-08-03 11:41 ` Peter Zijlstra
2015-08-03 13:01 ` Vineet Gupta
2015-08-03 13:50 ` Vineet Gupta
2015-08-03 14:08 ` Peter Zijlstra
2015-08-03 11:50 ` Peter Zijlstra
2015-08-03 13:02 ` Vineet Gupta
2015-08-03 13:06 ` Peter Zijlstra
2015-08-03 10:03 ` [PATCH 6/6] ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle Vineet Gupta
2015-08-03 11:43 ` Peter Zijlstra
2015-08-03 14:40 ` Vineet Gupta
2015-08-03 14:42 ` Peter Zijlstra
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1438596188-10875-3-git-send-email-vgupta@synopsys.com \
--to=vineet.gupta1@synopsys.com \
--cc=arc-linux-dev@synopsys.com \
--cc=linux-kernel@vger.kernel.org \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox