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Date: Tue, 10 Oct 2017 04:05:07 -0700
From: tip-bot for Kirill Tkhai <tipbot@...or.com>
To: linux-tip-commits@...r.kernel.org
Cc: torvalds@...ux-foundation.org, linux-kernel@...r.kernel.org,
peterz@...radead.org, mingo@...nel.org, hpa@...or.com,
tglx@...utronix.de, ktkhai@...tuozzo.com
Subject: [tip:locking/core] locking/arch, x86: Add __down_read_killable()
Commit-ID: 19c60923010b3f56f10ca1fb6d537c9cc852b3f1
Gitweb: https://git.kernel.org/tip/19c60923010b3f56f10ca1fb6d537c9cc852b3f1
Author: Kirill Tkhai <ktkhai@...tuozzo.com>
AuthorDate: Fri, 29 Sep 2017 19:06:28 +0300
Committer: Ingo Molnar <mingo@...nel.org>
CommitDate: Tue, 10 Oct 2017 11:50:15 +0200
locking/arch, x86: Add __down_read_killable()
Similar to __down_write_killable(), add read killable primitive:
extract current __down_read() code to macros and teach it to get
different functions as slow_path argument:
store ax register to ret, and add sp register and preserve its value.
Add call_rwsem_down_read_failed_killable() assembly entry similar
to call_rwsem_down_read_failed():
push dx register to stack in additional to common registers,
as it's not declarated as modifiable in ____down_read().
Signed-off-by: Kirill Tkhai <ktkhai@...tuozzo.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: arnd@...db.de
Cc: avagin@...tuozzo.com
Cc: davem@...emloft.net
Cc: fenghua.yu@...el.com
Cc: gorcunov@...tuozzo.com
Cc: heiko.carstens@...ibm.com
Cc: hpa@...or.com
Cc: ink@...assic.park.msu.ru
Cc: mattst88@...il.com
Cc: rientjes@...gle.com
Cc: rth@...ddle.net
Cc: schwidefsky@...ibm.com
Cc: tony.luck@...el.com
Cc: viro@...iv.linux.org.uk
Link: http://lkml.kernel.org/r/150670118802.23930.1316107715255410256.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
arch/x86/include/asm/rwsem.h | 35 +++++++++++++++++++++++++----------
arch/x86/lib/rwsem.S | 12 ++++++++++++
2 files changed, 37 insertions(+), 10 deletions(-)
diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h
index a8f486e..1e51195 100644
--- a/arch/x86/include/asm/rwsem.h
+++ b/arch/x86/include/asm/rwsem.h
@@ -60,18 +60,33 @@
/*
* lock for reading
*/
+#define ____down_read(sem, slow_path) \
+({ \
+ struct rw_semaphore* ret; \
+ asm volatile("# beginning down_read\n\t" \
+ LOCK_PREFIX _ASM_INC "(%[sem])\n\t" \
+ /* adds 0x00000001 */ \
+ " jns 1f\n" \
+ " call " slow_path "\n" \
+ "1:\n\t" \
+ "# ending down_read\n\t" \
+ : "+m" (sem->count), "=a" (ret), \
+ ASM_CALL_CONSTRAINT \
+ : [sem] "a" (sem) \
+ : "memory", "cc"); \
+ ret; \
+})
+
static inline void __down_read(struct rw_semaphore *sem)
{
- asm volatile("# beginning down_read\n\t"
- LOCK_PREFIX _ASM_INC "(%[sem])\n\t"
- /* adds 0x00000001 */
- " jns 1f\n"
- " call call_rwsem_down_read_failed\n"
- "1:\n\t"
- "# ending down_read\n\t"
- : "+m" (sem->count)
- : [sem] "a" (sem)
- : "memory", "cc");
+ ____down_read(sem, "call_rwsem_down_read_failed");
+}
+
+static inline int __down_read_killable(struct rw_semaphore *sem)
+{
+ if (IS_ERR(____down_read(sem, "call_rwsem_down_read_failed_killable")))
+ return -EINTR;
+ return 0;
}
/*
diff --git a/arch/x86/lib/rwsem.S b/arch/x86/lib/rwsem.S
index bf2c607..dc2ab6e 100644
--- a/arch/x86/lib/rwsem.S
+++ b/arch/x86/lib/rwsem.S
@@ -98,6 +98,18 @@ ENTRY(call_rwsem_down_read_failed)
ret
ENDPROC(call_rwsem_down_read_failed)
+ENTRY(call_rwsem_down_read_failed_killable)
+ FRAME_BEGIN
+ save_common_regs
+ __ASM_SIZE(push,) %__ASM_REG(dx)
+ movq %rax,%rdi
+ call rwsem_down_read_failed_killable
+ __ASM_SIZE(pop,) %__ASM_REG(dx)
+ restore_common_regs
+ FRAME_END
+ ret
+ENDPROC(call_rwsem_down_read_failed_killable)
+
ENTRY(call_rwsem_down_write_failed)
FRAME_BEGIN
save_common_regs
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