From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Jones Subject: [PATCH v5 16/19] arm: Add spinlock implementation Date: Wed, 11 Jun 2014 16:01:31 +0200 Message-ID: <1402495294-30737-17-git-send-email-drjones@redhat.com> References: <1402495294-30737-1-git-send-email-drjones@redhat.com> Cc: christoffer.dall@linaro.org, pbonzini@redhat.com To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:1824 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932307AbaFKOCD (ORCPT ); Wed, 11 Jun 2014 10:02:03 -0400 In-Reply-To: <1402495294-30737-1-git-send-email-drjones@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: From: Christoffer Dall Add simple busy-wait spinlock implementation for ARM. Signed-off-by: Christoffer Dall Signed-off-by: Andrew Jones --- config/config-arm.mak | 3 ++- lib/arm/asm/spinlock.h | 9 ++------- lib/arm/spinlock.c | 28 ++++++++++++++++++++++++++++ 3 files changed, 32 insertions(+), 8 deletions(-) create mode 100644 lib/arm/spinlock.c diff --git a/config/config-arm.mak b/config/config-arm.mak index 915b1cc318d79..d150807ec6fe4 100644 --- a/config/config-arm.mak +++ b/config/config-arm.mak @@ -35,7 +35,8 @@ cflatobjs += \ lib/virtio.o \ lib/virtio-testdev.o \ lib/arm/io.o \ - lib/arm/setup.o + lib/arm/setup.o \ + lib/arm/spinlock.o libeabi = lib/arm/libeabi.a eabiobjs = lib/arm/eabi_compat.o diff --git a/lib/arm/asm/spinlock.h b/lib/arm/asm/spinlock.h index 04f5a1a5538e2..2118a4b3751e0 100644 --- a/lib/arm/asm/spinlock.h +++ b/lib/arm/asm/spinlock.h @@ -5,12 +5,7 @@ struct spinlock { int v; }; -//TODO -static inline void spin_lock(struct spinlock *lock __unused) -{ -} -static inline void spin_unlock(struct spinlock *lock __unused) -{ -} +extern void spin_lock(struct spinlock *lock); +extern void spin_unlock(struct spinlock *lock); #endif /* _ASMARM_SPINLOCK_H_ */ diff --git a/lib/arm/spinlock.c b/lib/arm/spinlock.c new file mode 100644 index 0000000000000..d8a6d4c3383d6 --- /dev/null +++ b/lib/arm/spinlock.c @@ -0,0 +1,28 @@ +#include "libcflat.h" +#include "asm/spinlock.h" +#include "asm/barrier.h" + +void spin_lock(struct spinlock *lock) +{ + u32 val, fail; + + dmb(); + do { + asm volatile( + "1: ldrex %0, [%2]\n" + " teq %0, #0\n" + " bne 1b\n" + " mov %0, #1\n" + " strex %1, %0, [%2]\n" + : "=&r" (val), "=&r" (fail) + : "r" (&lock->v) + : "cc" ); + } while (fail); + dmb(); +} + +void spin_unlock(struct spinlock *lock) +{ + lock->v = 0; + dmb(); +} -- 1.9.3