[MIPS] FPU ownership management & preemption fixes

[mirror_ubuntu-artful-kernel.git] / include / asm-mips / fpu.h

diff --git a/include/asm-mips/fpu.h b/include/asm-mips/fpu.h
index efef843b93f0c1694a2084f1a502523a5ac69318..4e12d1f9534f9d99d43123c0cb517887946b5443 100644 (file)
--- a/include/asm-mips/fpu.h
+++ b/include/asm-mips/fpu.h
@@ -27,11 +27,11 @@
 struct sigcontext;
 struct sigcontext32;
 
-extern asmlinkage int (*save_fp_context)(struct sigcontext *sc);
-extern asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
+extern asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
+extern asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
 
-extern asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
-extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
+extern asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
+extern asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
 
 extern void fpu_emulator_init_fpu(void);
 extern void _init_fpu(void);
@@ -68,6 +68,8 @@ do {                                                                  \
        /* We don't care about the c0 hazard here  */                   \
 } while (0)
 
+#define __fpu_enabled()        (read_c0_status() & ST0_CU1)
+
 #define enable_fpu()                                                   \
 do {                                                                   \
        if (cpu_has_fpu)                                                \
@@ -93,31 +95,47 @@ static inline int is_fpu_owner(void)
        return cpu_has_fpu && __is_fpu_owner();
 }
 
-static inline void own_fpu(void)
+static inline void __own_fpu(void)
 {
-       if (cpu_has_fpu) {
-               __enable_fpu();
-               KSTK_STATUS(current) |= ST0_CU1;
-               set_thread_flag(TIF_USEDFPU);
+       __enable_fpu();
+       KSTK_STATUS(current) |= ST0_CU1;
+       set_thread_flag(TIF_USEDFPU);
+}
+
+static inline void own_fpu(int restore)
+{
+       preempt_disable();
+       if (cpu_has_fpu && !__is_fpu_owner()) {
+               __own_fpu();
+               if (restore)
+                       _restore_fp(current);
        }
+       preempt_enable();
 }
 
-static inline void lose_fpu(void)
+static inline void lose_fpu(int save)
 {
-       if (cpu_has_fpu) {
+       preempt_disable();
+       if (is_fpu_owner()) {
+               if (save)
+                       _save_fp(current);
                KSTK_STATUS(current) &= ~ST0_CU1;
                clear_thread_flag(TIF_USEDFPU);
                __disable_fpu();
        }
+       preempt_enable();
 }
 
 static inline void init_fpu(void)
 {
+       preempt_disable();
        if (cpu_has_fpu) {
+               __own_fpu();
                _init_fpu();
        } else {
                fpu_emulator_init_fpu();
        }
+       preempt_enable();
 }
 
 static inline void save_fp(struct task_struct *tsk)
@@ -144,4 +162,18 @@ static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
        return tsk->thread.fpu.fpr;
 }
 
+static inline void enable_fp_in_kernel(void)
+{
+       set_thread_flag(TIF_ALLOW_FP_IN_KERNEL);
+       /* make sure CU1 and FPU ownership are consistent */
+       if (!__is_fpu_owner() && __fpu_enabled())
+               __disable_fpu();
+}
+
+static inline void disable_fp_in_kernel(void)
+{
+       BUG_ON(!__is_fpu_owner() && __fpu_enabled());
+       clear_thread_flag(TIF_ALLOW_FP_IN_KERNEL);
+}
+
 #endif /* _ASM_FPU_H */