Merge branch 'master' into sh/hw-breakpoints
Conflict between FPU thread flag migration and debug
thread flag addition.
Conflicts:
arch/sh/include/asm/thread_info.h
arch/sh/include/asm/ubc.h
arch/sh/kernel/process_32.c
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 4a2c866..7399d78 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -133,7 +133,10 @@
regs.regs[5] = (unsigned long)fn;
regs.pc = (unsigned long)kernel_thread_helper;
- regs.sr = (1 << 30);
+ regs.sr = SR_MD;
+#if defined(CONFIG_SH_FPU)
+ regs.sr |= SR_FD;
+#endif
/* Ok, create the new process.. */
pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
@@ -141,6 +144,7 @@
return pid;
}
+EXPORT_SYMBOL(kernel_thread);
/*
* Free current thread data structures etc..
@@ -184,6 +188,16 @@
return fpvalid;
}
+EXPORT_SYMBOL(dump_fpu);
+
+/*
+ * This gets called before we allocate a new thread and copy
+ * the current task into it.
+ */
+void prepare_to_copy(struct task_struct *tsk)
+{
+ unlazy_fpu(tsk, task_pt_regs(tsk));
+}
asmlinkage void ret_from_fork(void);
@@ -193,15 +207,10 @@
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
- struct task_struct *tsk = current;
-
-#if defined(CONFIG_SH_FPU)
- unlazy_fpu(tsk, regs);
- p->thread.fpu = tsk->thread.fpu;
- copy_to_stopped_child_used_math(p);
-#endif
#if defined(CONFIG_SH_DSP)
+ struct task_struct *tsk = current;
+
if (is_dsp_enabled(tsk)) {
/* We can use the __save_dsp or just copy the struct:
* __save_dsp(p);
@@ -220,6 +229,8 @@
} else {
childregs->regs[15] = (unsigned long)childregs;
ti->addr_limit = KERNEL_DS;
+ ti->status &= ~TS_USEDFPU;
+ p->fpu_counter = 0;
}
if (clone_flags & CLONE_SETTLS)
@@ -242,9 +253,13 @@
__notrace_funcgraph struct task_struct *
__switch_to(struct task_struct *prev, struct task_struct *next)
{
-#if defined(CONFIG_SH_FPU)
+ struct thread_struct *next_t = &next->thread;
+
unlazy_fpu(prev, task_pt_regs(prev));
-#endif
+
+ /* we're going to use this soon, after a few expensive things */
+ if (next->fpu_counter > 5)
+ prefetch(&next_t->fpu.hard);
#ifdef CONFIG_MMU
/*
@@ -256,6 +271,14 @@
: "r" (task_thread_info(next)));
#endif
+ /*
+ * If the task has used fpu the last 5 timeslices, just do a full
+ * restore of the math state immediately to avoid the trap; the
+ * chances of needing FPU soon are obviously high now
+ */
+ if (next->fpu_counter > 5)
+ fpu_state_restore(task_pt_regs(next));
+
return prev;
}