#include <linux/sched.h>
#include <linux/init.h>
+#include <linux/kernel_stat.h>
#include <asm/processor.h>
#include <asm/sigcontext.h>
#include <asm/user.h>
-extern unsigned long mxcsr_feature_mask;
extern void mxcsr_feature_mask_init(void);
extern void init_fpu(struct task_struct *);
+
/*
* FPU lazy state save handling...
*/
-extern void restore_fpu( struct task_struct *tsk );
+
+/*
+ * The "nop" is needed to make the instructions the same
+ * length.
+ */
+#define restore_fpu(tsk) \
+ alternative_input( \
+ "nop ; frstor %1", \
+ "fxrstor %1", \
+ X86_FEATURE_FXSR, \
+ "m" ((tsk)->thread.i387.fxsave))
extern void kernel_fpu_begin(void);
#define kernel_fpu_end() do { stts(); preempt_enable(); } while(0)
+/* We need a safe address that is cheap to find and that is already
+ in L1 during context switch. The best choices are unfortunately
+ different for UP and SMP */
+#ifdef CONFIG_SMP
+#define safe_address (__per_cpu_offset[0])
+#else
+#define safe_address (kstat_cpu(0).cpustat.user)
+#endif
+
/*
* These must be called with preempt disabled
*/
static inline void __save_init_fpu( struct task_struct *tsk )
{
- if ( cpu_has_fxsr ) {
- asm volatile( "fxsave %0 ; fnclex"
- : "=m" (tsk->thread.i387.fxsave) );
- } else {
- asm volatile( "fnsave %0 ; fwait"
- : "=m" (tsk->thread.i387.fsave) );
- }
- tsk->thread_info->status &= ~TS_USEDFPU;
+ /* Use more nops than strictly needed in case the compiler
+ varies code */
+ alternative_input(
+ "fnsave %[fx] ;fwait;" GENERIC_NOP8 GENERIC_NOP4,
+ "fxsave %[fx]\n"
+ "bt $7,%[fsw] ; jnc 1f ; fnclex\n1:",
+ X86_FEATURE_FXSR,
+ [fx] "m" (tsk->thread.i387.fxsave),
+ [fsw] "m" (tsk->thread.i387.fxsave.swd) : "memory");
+ /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
+ is pending. Clear the x87 state here by setting it to fixed
+ values. safe_address is a random variable that should be in L1 */
+ alternative_input(
+ GENERIC_NOP8 GENERIC_NOP2,
+ "emms\n\t" /* clear stack tags */
+ "fildl %[addr]", /* set F?P to defined value */
+ X86_FEATURE_FXSAVE_LEAK,
+ [addr] "m" (safe_address));
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
}
#define __unlazy_fpu( tsk ) do { \
- if ((tsk)->thread_info->status & TS_USEDFPU) \
- save_init_fpu( tsk ); \
+ if (task_thread_info(tsk)->status & TS_USEDFPU) \
+ save_init_fpu( tsk ); \
+ else \
+ tsk->fpu_counter = 0; \
} while (0)
#define __clear_fpu( tsk ) \
do { \
- if ((tsk)->thread_info->status & TS_USEDFPU) { \
- asm volatile("fwait"); \
- (tsk)->thread_info->status &= ~TS_USEDFPU; \
+ if (task_thread_info(tsk)->status & TS_USEDFPU) { \
+ asm volatile("fnclex ; fwait"); \
+ task_thread_info(tsk)->status &= ~TS_USEDFPU; \
stts(); \
} \
} while (0)
*/
extern unsigned short get_fpu_cwd( struct task_struct *tsk );
extern unsigned short get_fpu_swd( struct task_struct *tsk );
-extern unsigned short get_fpu_twd( struct task_struct *tsk );
extern unsigned short get_fpu_mxcsr( struct task_struct *tsk );
-
-extern void set_fpu_cwd( struct task_struct *tsk, unsigned short cwd );
-extern void set_fpu_swd( struct task_struct *tsk, unsigned short swd );
-extern void set_fpu_twd( struct task_struct *tsk, unsigned short twd );
+extern asmlinkage void math_state_restore(void);
/*
* Signal frame handlers...
extern int restore_i387( struct _fpstate __user *buf );
/*
- * ptrace request handers...
+ * ptrace request handlers...
*/
-extern int get_fpregs( struct user_i387_struct __user *buf,
- struct task_struct *tsk );
-extern int set_fpregs( struct task_struct *tsk,
- struct user_i387_struct __user *buf );
+extern int get_fpregs(struct user_i387_struct *, struct task_struct *);
+extern int set_fpregs(struct task_struct *, const struct user_i387_struct *);
+extern void updated_fpxregs(struct task_struct *tsk);
-extern int get_fpxregs( struct user_fxsr_struct __user *buf,
- struct task_struct *tsk );
-extern int set_fpxregs( struct task_struct *tsk,
- struct user_fxsr_struct __user *buf );
/*
* FPU state for core dumps...
*/
extern int dump_fpu( struct pt_regs *regs,
struct user_i387_struct *fpu );
-extern int dump_extended_fpu( struct pt_regs *regs,
- struct user_fxsr_struct *fpu );
#endif /* __ASM_I386_I387_H */