include/asm-x86/xsave.h

   1 #ifndef __ASM_X86_XSAVE_H
   2 #define __ASM_X86_XSAVE_H
   3
   4 #include <asm/processor.h>
   5 #include <asm/i387.h>
   6
   7 #define XSTATE_FP       0x1
   8 #define XSTATE_SSE      0x2
   9
  10 #define XSTATE_FPSSE    (XSTATE_FP | XSTATE_SSE)
  11
  12 #define FXSAVE_SIZE     512
  13
  14 /*
  15  * These are the features that the OS can handle currently.
  16  */
  17 #define XCNTXT_LMASK    (XSTATE_FP | XSTATE_SSE)
  18 #define XCNTXT_HMASK    0x0
  19
  20 #ifdef CONFIG_X86_64
  21 #define REX_PREFIX      "0x48, "
  22 #else
  23 #define REX_PREFIX
  24 #endif
  25
  26 extern unsigned int xstate_size, pcntxt_hmask, pcntxt_lmask;
  27 extern struct xsave_struct *init_xstate_buf;
  28
  29 extern void xsave_cntxt_init(void);
  30 extern void xsave_init(void);
  31 extern int init_fpu(struct task_struct *child);
  32 extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
  33                             void __user *fpstate,
  34                             struct _fpx_sw_bytes *sw);
  35
  36 static inline int xrstor_checking(struct xsave_struct *fx)
  37 {
  38         int err;
  39
  40         asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
  41                      "2:\n"
  42                      ".section .fixup,\"ax\"\n"
  43                      "3:  movl $-1,%[err]\n"
  44                      "    jmp  2b\n"
  45                      ".previous\n"
  46                      _ASM_EXTABLE(1b, 3b)
  47                      : [err] "=r" (err)
  48                      : "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
  49                      : "memory");
  50
  51         return err;
  52 }
  53
  54 static inline int xsave_user(struct xsave_struct __user *buf)
  55 {
  56         int err;
  57         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
  58                              "2:\n"
  59                              ".section .fixup,\"ax\"\n"
  60                              "3:  movl $-1,%[err]\n"
  61                              "    jmp  2b\n"
  62                              ".previous\n"
  63                              ".section __ex_table,\"a\"\n"
  64                              _ASM_ALIGN "\n"
  65                              _ASM_PTR "1b,3b\n"
  66                              ".previous"
  67                              : [err] "=r" (err)
  68                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
  69                              : "memory");
  70         if (unlikely(err) && __clear_user(buf, xstate_size))
  71                 err = -EFAULT;
  72         /* No need to clear here because the caller clears USED_MATH */
  73         return err;
  74 }
  75
  76 static inline int xrestore_user(struct xsave_struct __user *buf,
  77                                 unsigned int lmask,
  78                                 unsigned int hmask)
  79 {
  80         int err;
  81         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
  82
  83         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
  84                              "2:\n"
  85                              ".section .fixup,\"ax\"\n"
  86                              "3:  movl $-1,%[err]\n"
  87                              "    jmp  2b\n"
  88                              ".previous\n"
  89                              ".section __ex_table,\"a\"\n"
  90                              _ASM_ALIGN "\n"
  91                              _ASM_PTR "1b,3b\n"
  92                              ".previous"
  93                              : [err] "=r" (err)
  94                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
  95                              : "memory");       /* memory required? */
  96         return err;
  97 }
  98
  99 static inline void xrstor_state(struct xsave_struct *fx, int lmask, int hmask)
 100 {
 101         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
 102                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 103                      :   "memory");
 104 }
 105
 106 static inline void xsave(struct task_struct *tsk)
 107 {
 108         /* This, however, we can work around by forcing the compiler to select
 109            an addressing mode that doesn't require extended registers. */
 110         __asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27"
 111                              : : "D" (&(tsk->thread.xstate->xsave)),
 112                                  "a" (-1), "d"(-1) : "memory");
 113 }
 114 #endif