arch/x86/include/asm/xsave.h

   1 #ifndef __ASM_X86_XSAVE_H
   2 #define __ASM_X86_XSAVE_H
   3
   4 #include <linux/types.h>
   5 #include <asm/processor.h>
   6 #include <asm/i387.h>
   7
   8 #define XSTATE_FP       0x1
   9 #define XSTATE_SSE      0x2
  10
  11 #define XSTATE_FPSSE    (XSTATE_FP | XSTATE_SSE)
  12
  13 #define FXSAVE_SIZE     512
  14
  15 /*
  16  * These are the features that the OS can handle currently.
  17  */
  18 #define XCNTXT_MASK     (XSTATE_FP | XSTATE_SSE)
  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;
  27 extern u64 pcntxt_mask;
  28 extern struct xsave_struct *init_xstate_buf;
  29
  30 extern void xsave_cntxt_init(void);
  31 extern void xsave_init(void);
  32 extern int init_fpu(struct task_struct *child);
  33 extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
  34                             void __user *fpstate,
  35                             struct _fpx_sw_bytes *sw);
  36
  37 static inline int xrstor_checking(struct xsave_struct *fx)
  38 {
  39         int err;
  40
  41         asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
  42                      "2:\n"
  43                      ".section .fixup,\"ax\"\n"
  44                      "3:  movl $-1,%[err]\n"
  45                      "    jmp  2b\n"
  46                      ".previous\n"
  47                      _ASM_EXTABLE(1b, 3b)
  48                      : [err] "=r" (err)
  49                      : "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
  50                      : "memory");
  51
  52         return err;
  53 }
  54
  55 static inline int xsave_user(struct xsave_struct __user *buf)
  56 {
  57         int err;
  58         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
  59                              "2:\n"
  60                              ".section .fixup,\"ax\"\n"
  61                              "3:  movl $-1,%[err]\n"
  62                              "    jmp  2b\n"
  63                              ".previous\n"
  64                              ".section __ex_table,\"a\"\n"
  65                              _ASM_ALIGN "\n"
  66                              _ASM_PTR "1b,3b\n"
  67                              ".previous"
  68                              : [err] "=r" (err)
  69                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
  70                              : "memory");
  71         if (unlikely(err) && __clear_user(buf, xstate_size))
  72                 err = -EFAULT;
  73         /* No need to clear here because the caller clears USED_MATH */
  74         return err;
  75 }
  76
  77 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
  78 {
  79         int err;
  80         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
  81         u32 lmask = mask;
  82         u32 hmask = mask >> 32;
  83
  84         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
  85                              "2:\n"
  86                              ".section .fixup,\"ax\"\n"
  87                              "3:  movl $-1,%[err]\n"
  88                              "    jmp  2b\n"
  89                              ".previous\n"
  90                              ".section __ex_table,\"a\"\n"
  91                              _ASM_ALIGN "\n"
  92                              _ASM_PTR "1b,3b\n"
  93                              ".previous"
  94                              : [err] "=r" (err)
  95                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
  96                              : "memory");       /* memory required? */
  97         return err;
  98 }
  99
 100 static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
 101 {
 102         u32 lmask = mask;
 103         u32 hmask = mask >> 32;
 104
 105         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
 106                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 107                      :   "memory");
 108 }
 109
 110 static inline void xsave(struct task_struct *tsk)
 111 {
 112         /* This, however, we can work around by forcing the compiler to select
 113            an addressing mode that doesn't require extended registers. */
 114         __asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27"
 115                              : : "D" (&(tsk->thread.xstate->xsave)),
 116                                  "a" (-1), "d"(-1) : "memory");
 117 }
 118 #endif