diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-02-06 11:36:23 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-02-15 21:39:53 +0000 |
| commit | ad187f956108e1c56b444706212bf08d84c0bee0 (patch) | |
| tree | 5aa54adb07016a87be9629aea20a6fd363d449c2 | |
| parent | 54cb3dbb4a1cccd6b1bffc169ff638f8e74daf44 (diff) | |
ARM: vfp ptrace: no point flushing hw context for PTRACE_GETVFPREGS
If we're only reading the VFP context via the ptrace call, there's
no need to invalidate the hardware context - we only need to do that
on PTRACE_SETVFPREGS. This allows more efficient monitoring of a
traced task.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/include/asm/thread_info.h | 3 | ||||
| -rw-r--r-- | arch/arm/kernel/ptrace.c | 6 | ||||
| -rw-r--r-- | arch/arm/vfp/vfpmodule.c | 25 |
3 files changed, 29 insertions, 5 deletions
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index 2dfb7d7a66e..b74970ec02c 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -115,7 +115,8 @@ extern void iwmmxt_task_restore(struct thread_info *, void *); extern void iwmmxt_task_release(struct thread_info *); extern void iwmmxt_task_switch(struct thread_info *); -extern void vfp_sync_state(struct thread_info *thread); +extern void vfp_sync_hwstate(struct thread_info *); +extern void vfp_flush_hwstate(struct thread_info *); #endif diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index bdf002bab6a..08f899fb76a 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -700,7 +700,7 @@ static int ptrace_getvfpregs(struct task_struct *tsk, void __user *data) union vfp_state *vfp = &thread->vfpstate; struct user_vfp __user *ufp = data; - vfp_sync_state(thread); + vfp_sync_hwstate(thread); /* copy the floating point registers */ if (copy_to_user(&ufp->fpregs, &vfp->hard.fpregs, @@ -723,7 +723,7 @@ static int ptrace_setvfpregs(struct task_struct *tsk, void __user *data) union vfp_state *vfp = &thread->vfpstate; struct user_vfp __user *ufp = data; - vfp_sync_state(thread); + vfp_sync_hwstate(thread); /* copy the floating point registers */ if (copy_from_user(&vfp->hard.fpregs, &ufp->fpregs, @@ -734,6 +734,8 @@ static int ptrace_setvfpregs(struct task_struct *tsk, void __user *data) if (get_user(vfp->hard.fpscr, &ufp->fpscr)) return -EFAULT; + vfp_flush_hwstate(thread); + return 0; } #endif diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 86a57aeeda4..def19f83d81 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -430,7 +430,11 @@ static inline void vfp_pm_init(void) { } * saved one. This function is used by the ptrace mechanism. */ #ifdef CONFIG_SMP -void vfp_sync_state(struct thread_info *thread) +void vfp_sync_hwstate(struct thread_info *thread) +{ +} + +void vfp_flush_hwstate(struct thread_info *thread) { /* * On SMP systems, the VFP state is automatically saved at every @@ -441,7 +445,7 @@ void vfp_sync_state(struct thread_info *thread) thread->vfpstate.hard.cpu = NR_CPUS; } #else -void vfp_sync_state(struct thread_info *thread) +void vfp_sync_hwstate(struct thread_info *thread) { unsigned int cpu = get_cpu(); @@ -457,6 +461,23 @@ void vfp_sync_state(struct thread_info *thread) */ fmxr(FPEXC, fpexc | FPEXC_EN); vfp_save_state(&thread->vfpstate, fpexc | FPEXC_EN); + fmxr(FPEXC, fpexc); + } + + put_cpu(); +} + +void vfp_flush_hwstate(struct thread_info *thread) +{ + unsigned int cpu = get_cpu(); + + /* + * If the thread we're interested in is the current owner of the + * hardware VFP state, then we need to save its state. + */ + if (last_VFP_context[cpu] == &thread->vfpstate) { + u32 fpexc = fmrx(FPEXC); + fmxr(FPEXC, fpexc & ~FPEXC_EN); /* |