8 files changed, 48 insertions, 42 deletions

diff --git a/arch/sh/include/asm/fpu.h b/arch/sh/include/asm/fpu.h
index bfd78e19de1b..d7709c06fac4 100644
--- a/arch/sh/include/asm/fpu.h
+++ b/arch/sh/include/asm/fpu.h
@@ -18,17 +18,14 @@ static inline void grab_fpu(struct pt_regs *regs)
 
 struct task_struct;
 
-extern void save_fpu(struct task_struct *__tsk, struct pt_regs *regs);
+extern void save_fpu(struct task_struct *__tsk);
 void fpu_state_restore(struct pt_regs *regs);
 #else
 
+#define save_fpu(tsk)           do { } while (0)
 #define release_fpu(regs)       do { } while (0)
 #define grab_fpu(regs)          do { } while (0)
 
-static inline void save_fpu(struct task_struct *tsk, struct pt_regs *regs)
-{
-        clear_tsk_thread_flag(tsk, TIF_USEDFPU);
-}
 #endif
 
 struct user_regset;
@@ -40,21 +37,28 @@ extern int fpregs_get(struct task_struct *target,
                       unsigned int pos, unsigned int count,
                       void *kbuf, void __user *ubuf);
 
+static inline void __unlazy_fpu(struct task_struct *tsk, struct pt_regs *regs)
+{
+        if (task_thread_info(tsk)->status & TS_USEDFPU) {
+                task_thread_info(tsk)->status &= ~TS_USEDFPU;
+                save_fpu(tsk);
+                release_fpu(regs);
+        } else
+                tsk->fpu_counter = 0;
+}
+
 static inline void unlazy_fpu(struct task_struct *tsk, struct pt_regs *regs)
 {
         preempt_disable();
-        if (test_tsk_thread_flag(tsk, TIF_USEDFPU))
-                save_fpu(tsk, regs);
-        else
-                tsk->fpu_counter = 0;
+        __unlazy_fpu(tsk, regs);
         preempt_enable();
 }
 
 static inline void clear_fpu(struct task_struct *tsk, struct pt_regs *regs)
 {
         preempt_disable();
-        if (test_tsk_thread_flag(tsk, TIF_USEDFPU)) {
-                clear_tsk_thread_flag(tsk, TIF_USEDFPU);
+        if (task_thread_info(tsk)->status & TS_USEDFPU) {
+                task_thread_info(tsk)->status &= ~TS_USEDFPU;
                 release_fpu(regs);
         }
         preempt_enable();
diff --git a/arch/sh/include/asm/processor_32.h b/arch/sh/include/asm/processor_32.h
index 9a8714945dc9..1f3d6fab660c 100644
--- a/arch/sh/include/asm/processor_32.h
+++ b/arch/sh/include/asm/processor_32.h
@@ -56,6 +56,7 @@ asmlinkage void __init sh_cpu_init(void);
 #define SR_DSP          0x00001000
 #define SR_IMASK        0x000000f0
 #define SR_FD           0x00008000
+#define SR_MD           0x40000000
 
 /*
  * DSP structure and data
@@ -136,7 +137,7 @@ struct mm_struct;
 extern void release_thread(struct task_struct *);
 
 /* Prepare to copy thread state - unlazy all lazy status */
-#define prepare_to_copy(tsk)    do { } while (0)
+void prepare_to_copy(struct task_struct *tsk);
 
 /*
  * create a kernel thread without removing it from tasklists
diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index 23eeed89467a..1f3d927e2265 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -51,6 +51,7 @@ struct thread_info {
         .task           = &tsk,                 \
         .exec_domain    = &default_exec_domain, \
         .flags          = 0,                    \
+        .status         = 0,                    \
         .cpu            = 0,                    \
         .preempt_count  = INIT_PREEMPT_COUNT,   \
         .addr_limit     = KERNEL_DS,            \
@@ -117,7 +118,6 @@ extern void free_thread_info(struct thread_info *ti);
 #define TIF_SECCOMP             6       /* secure computing */
 #define TIF_NOTIFY_RESUME       7       /* callback before returning to user */
 #define TIF_SYSCALL_TRACEPOINT  8       /* for ftrace syscall instrumentation */
-#define TIF_USEDFPU             16      /* FPU was used by this task this quantum (SMP) */
 #define TIF_POLLING_NRFLAG      17      /* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE              18
 #define TIF_FREEZE              19      /* Freezing for suspend */
@@ -130,7 +130,6 @@ extern void free_thread_info(struct thread_info *ti);
 #define _TIF_SECCOMP            (1 << TIF_SECCOMP)
 #define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
 #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
-#define _TIF_USEDFPU            (1 << TIF_USEDFPU)
 #define _TIF_POLLING_NRFLAG     (1 << TIF_POLLING_NRFLAG)
 #define _TIF_FREEZE             (1 << TIF_FREEZE)
 
@@ -163,6 +162,7 @@ extern void free_thread_info(struct thread_info *ti);
  * have to worry about atomic accesses.
  */
 #define TS_RESTORE_SIGMASK      0x0001  /* restore signal mask in do_signal() */
+#define TS_USEDFPU              0x0002  /* FPU used by this task this quantum */
 
 #ifndef __ASSEMBLY__
 #define HAVE_SET_RESTORE_SIGMASK        1
diff --git a/arch/sh/kernel/cpu/init.c b/arch/sh/kernel/cpu/init.c
index 580d58b94cc5..ad9dfff9427c 100644
--- a/arch/sh/kernel/cpu/init.c
+++ b/arch/sh/kernel/cpu/init.c
@@ -311,12 +311,12 @@ asmlinkage void __init sh_cpu_init(void)
         if (fpu_disabled) {
                 printk("FPU Disabled\n");
                 current_cpu_data.flags &= ~CPU_HAS_FPU;
-                disable_fpu();
         }
 
         /* FPU initialization */
+        disable_fpu();
         if ((current_cpu_data.flags & CPU_HAS_FPU)) {
-                clear_thread_flag(TIF_USEDFPU);
+                current_thread_info()->status &= ~TS_USEDFPU;
                 clear_used_math();
         }
 
diff --git a/arch/sh/kernel/cpu/sh2a/fpu.c b/arch/sh/kernel/cpu/sh2a/fpu.c
index 6df2fb98eb30..13817ee49d52 100644
--- a/arch/sh/kernel/cpu/sh2a/fpu.c
+++ b/arch/sh/kernel/cpu/sh2a/fpu.c
@@ -25,14 +25,12 @@
 
 /*
  * Save FPU registers onto task structure.
- * Assume called with FPU enabled (SR.FD=0).
  */
 void
-save_fpu(struct task_struct *tsk, struct pt_regs *regs)
+save_fpu(struct task_struct *tsk)
 {
         unsigned long dummy;
 
-        clear_tsk_thread_flag(tsk, TIF_USEDFPU);
         enable_fpu();
         asm volatile("sts.l     fpul, @-%0\n\t"
                      "sts.l     fpscr, @-%0\n\t"
@@ -60,7 +58,6 @@ save_fpu(struct task_struct *tsk, struct pt_regs *regs)
                      : "memory");
 
         disable_fpu();
-        release_fpu(regs);
 }
 
 static void
@@ -598,13 +595,13 @@ BUILD_TRAP_HANDLER(fpu_error)
         struct task_struct *tsk = current;
         TRAP_HANDLER_DECL;
 
-        save_fpu(tsk, regs);
+        __unlazy_fpu(tsk, regs);
         if (ieee_fpe_handler(regs)) {
                 tsk->thread.fpu.hard.fpscr &=
                         ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK);
                 grab_fpu(regs);
                 restore_fpu(tsk);
-                set_tsk_thread_flag(tsk, TIF_USEDFPU);
+                task_thread_info(tsk)->status |= TS_USEDFPU;
                 return;
         }
 
@@ -630,5 +627,5 @@ BUILD_TRAP_HANDLER(fpu_state_restore)
                 fpu_init();
                 set_used_math();
         }
-        set_tsk_thread_flag(tsk, TIF_USEDFPU);
+        task_thread_info(tsk)->status |= TS_USEDFPU;
 }
diff --git a/arch/sh/kernel/cpu/sh4/fpu.c b/arch/sh/kernel/cpu/sh4/fpu.c
index d79226fa59d1..e97857aec8a0 100644
--- a/arch/sh/kernel/cpu/sh4/fpu.c
+++ b/arch/sh/kernel/cpu/sh4/fpu.c
@@ -41,13 +41,11 @@ static unsigned int fpu_exception_flags;
 
 /*
  * Save FPU registers onto task structure.
- * Assume called with FPU enabled (SR.FD=0).
  */
-void save_fpu(struct task_struct *tsk, struct pt_regs *regs)
+void save_fpu(struct task_struct *tsk)
 {
         unsigned long dummy;
 
-        clear_tsk_thread_flag(tsk, TIF_USEDFPU);
         enable_fpu();
         asm volatile ("sts.l    fpul, @-%0\n\t"
                       "sts.l    fpscr, @-%0\n\t"
@@ -92,7 +90,6 @@ void save_fpu(struct task_struct *tsk, struct pt_regs *regs)
                       :"memory");
 
         disable_fpu();
-        release_fpu(regs);
 }
 
 static void restore_fpu(struct task_struct *tsk)
@@ -285,7 +282,6 @@ static int ieee_fpe_handler(struct pt_regs *regs)
                 /* fcnvsd */
                 struct task_struct *tsk = current;
 
-                save_fpu(tsk, regs);
                 if ((tsk->thread.fpu.hard.fpscr & FPSCR_CAUSE_ERROR))
                         /* FPU error */
                         denormal_to_double(&tsk->thread.fpu.hard,
@@ -462,7 +458,7 @@ BUILD_TRAP_HANDLER(fpu_error)
         struct task_struct *tsk = current;
         TRAP_HANDLER_DECL;
 
-        save_fpu(tsk, regs);
+        __unlazy_fpu(tsk, regs);
         fpu_exception_flags = 0;
         if (ieee_fpe_handler(regs)) {
                 tsk->thread.fpu.hard.fpscr &=
@@ -473,7 +469,7 @@ BUILD_TRAP_HANDLER(fpu_error)
                 tsk->thread.fpu.hard.fpscr |= (fpu_exception_flags >> 10);
                 grab_fpu(regs);
                 restore_fpu(tsk);
-                set_tsk_thread_flag(tsk, TIF_USEDFPU);
+                task_thread_info(tsk)->status |= TS_USEDFPU;
                 if ((((tsk->thread.fpu.hard.fpscr & FPSCR_ENABLE_MASK) >> 7) &
                      (fpu_exception_flags >> 2)) == 0) {
                         return;
@@ -502,7 +498,7 @@ void fpu_state_restore(struct pt_regs *regs)
                 fpu_init();
                 set_used_math();
         }
-        set_tsk_thread_flag(tsk, TIF_USEDFPU);
+        task_thread_info(tsk)->status |= TS_USEDFPU;
         tsk->fpu_counter++;
 }
 
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 7733f5fa6bb5..d721f9297c09 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -134,7 +134,10 @@ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
         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,
@@ -189,6 +192,15 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 }
 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);
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
@@ -197,16 +209,10 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 {
         struct thread_info *ti = task_thread_info(p);
         struct pt_regs *childregs;
-#if defined(CONFIG_SH_FPU) || defined(CONFIG_SH_DSP)
+#if defined(CONFIG_SH_DSP)
         struct task_struct *tsk = current;
 #endif
 
-#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)
         if (is_dsp_enabled(tsk)) {
                 /* We can use the __save_dsp or just copy the struct:
@@ -226,6 +232,8 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
         } 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)
diff --git a/arch/sh/math-emu/math.c b/arch/sh/math-emu/math.c
index ac2d7abd2567..d6c15cae0912 100644
--- a/arch/sh/math-emu/math.c
+++ b/arch/sh/math-emu/math.c
@@ -558,7 +558,7 @@ static int ieee_fpe_handler(struct pt_regs *regs)
                                             (finsn >> 8) & 0xf);
                         tsk->thread.fpu.hard.fpscr &=
                                 ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK);
-                        set_tsk_thread_flag(tsk, TIF_USEDFPU);
+                        task_thread_info(tsk)->status |= TS_USEDFPU;
                 } else {
                         info.si_signo = SIGFPE;
                         info.si_errno = 0;
@@ -619,10 +619,10 @@ int do_fpu_inst(unsigned short inst, struct pt_regs *regs)
         struct task_struct *tsk = current;
         struct sh_fpu_soft_struct *fpu = &(tsk->thread.fpu.soft);
 
-        if (!test_tsk_thread_flag(tsk, TIF_USEDFPU)) {
+        if (!(task_thread_info(tsk)->status & TS_USEDFPU)) {
                 /* initialize once. */
                 fpu_init(fpu);
-                set_tsk_thread_flag(tsk, TIF_USEDFPU);
+                task_thread_info(tsk)->status |= TS_USEDFPU;
         }
 
         return fpu_emulate(inst, fpu, regs);