From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kirill Tkhai Date: Fri, 29 Sep 2017 16:06:28 +0000 Subject: [PATCH REBASED 4/6] x86: Add __down_read_killable() Message-Id: <150670118802.23930.1316107715255410256.stgit@localhost.localdomain> List-Id: References: <150670038738.23930.7190484711222807884.stgit@localhost.localdomain> In-Reply-To: <150670038738.23930.7190484711222807884.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org, avagin@virtuozzo.com, peterz@infradead.org, heiko.carstens@de.ibm.com, hpa@zytor.com, gorcunov@virtuozzo.com, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, x86@kernel.org, mingo@redhat.com, mattst88@gmail.com, fenghua.yu@intel.com, arnd@arndb.de, ktkhai@virtuozzo.com, ink@jurassic.park.msu.ru, tglx@linutronix.de, rth@twiddle.net, tony.luck@intel.com, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, schwidefsky@de.ibm.com, davem@davemloft.net, rientjes@google.com, viro@zeniv.linux.org.uk 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 --- 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 a8f486e7a124..1e51195c0b63 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 bf2c6074efd2..dc2ab6ea6768 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