Commit-ID: 19c60923010b3f56f10ca1fb6d537c9cc852b3f1 Gitweb: https://git.kernel.org/tip/19c60923010b3f56f10ca1fb6d537c9cc852b3f1 Author: Kirill Tkhai <ktk...@virtuozzo.com> AuthorDate: Fri, 29 Sep 2017 19:06:28 +0300 Committer: Ingo Molnar <mi...@kernel.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 <ktk...@virtuozzo.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: a...@arndb.de Cc: ava...@virtuozzo.com Cc: da...@davemloft.net Cc: fenghua...@intel.com Cc: gorcu...@virtuozzo.com Cc: heiko.carst...@de.ibm.com Cc: h...@zytor.com Cc: i...@jurassic.park.msu.ru Cc: matts...@gmail.com Cc: rient...@google.com Cc: r...@twiddle.net Cc: schwidef...@de.ibm.com Cc: tony.l...@intel.com Cc: v...@zeniv.linux.org.uk Link: http://lkml.kernel.org/r/150670118802.23930.1316107715255410256.stgit@localhost.localdomain Signed-off-by: Ingo Molnar <mi...@kernel.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
