[MIPS] FPU ownership management & preemption fixes
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/cpu-features.h b/include/asm-mips/cpu-features.h
index eadca26..5e4bed1 100644
--- a/include/asm-mips/cpu-features.h
+++ b/include/asm-mips/cpu-features.h
@@ -40,6 +40,9 @@
#endif
#ifndef cpu_has_fpu
#define cpu_has_fpu (current_cpu_data.options & MIPS_CPU_FPU)
+#define raw_cpu_has_fpu (raw_current_cpu_data.options & MIPS_CPU_FPU)
+#else
+#define raw_cpu_has_fpu cpu_has_fpu
#endif
#ifndef cpu_has_32fpr
#define cpu_has_32fpr (cpu_data[0].options & MIPS_CPU_32FPR)
diff --git a/include/asm-mips/cpu-info.h b/include/asm-mips/cpu-info.h
index 610d0cd..22fe845 100644
--- a/include/asm-mips/cpu-info.h
+++ b/include/asm-mips/cpu-info.h
@@ -87,6 +87,7 @@
extern struct cpuinfo_mips cpu_data[];
#define current_cpu_data cpu_data[smp_processor_id()]
+#define raw_current_cpu_data cpu_data[raw_smp_processor_id()]
extern void cpu_probe(void);
extern void cpu_report(void);
diff --git a/include/asm-mips/fpu.h b/include/asm-mips/fpu.h
index efef843b..4e12d1f 100644
--- 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 @@
/* 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 @@
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 lose_fpu(void)
+static inline void own_fpu(int restore)
{
- if (cpu_has_fpu) {
+ preempt_disable();
+ if (cpu_has_fpu && !__is_fpu_owner()) {
+ __own_fpu();
+ if (restore)
+ _restore_fp(current);
+ }
+ preempt_enable();
+}
+
+static inline void lose_fpu(int save)
+{
+ 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 @@
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 */
diff --git a/include/asm-mips/thread_info.h b/include/asm-mips/thread_info.h
index fbcda82..6cf05f4 100644
--- a/include/asm-mips/thread_info.h
+++ b/include/asm-mips/thread_info.h
@@ -119,6 +119,7 @@
#define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 18
#define TIF_FREEZE 19
+#define TIF_ALLOW_FP_IN_KERNEL 20
#define TIF_SYSCALL_TRACE 31 /* syscall trace active */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)