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 #define XSTATE_YMM      0x4
  11
  12 #define XSTATE_FPSSE    (XSTATE_FP | XSTATE_SSE)
  13
  14 #define FXSAVE_SIZE     512
  15
  16 /*
  17  * These are the features that the OS can handle currently.
  18  */
  19 #define XCNTXT_MASK     (XSTATE_FP | XSTATE_SSE | XSTATE_YMM)
  20
  21 #ifdef CONFIG_X86_64
  22 #define REX_PREFIX      "0x48, "
  23 #else
  24 #define REX_PREFIX
  25 #endif
  26
  27 extern unsigned int xstate_size;
  28 extern u64 pcntxt_mask;
  29 extern struct xsave_struct *init_xstate_buf;
  30
  31 extern void xsave_cntxt_init(void);
  32 extern void xsave_init(void);
  33 extern int init_fpu(struct task_struct *child);
  34 extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
  35                             void __user *fpstate,
  36                             struct _fpx_sw_bytes *sw);
  37
  38 static inline int xrstor_checking(struct xsave_struct *fx)
  39 {
  40         int err;
  41
  42         asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
  43                      "2:\n"
  44                      ".section .fixup,\"ax\"\n"
  45                      "3:  movl $-1,%[err]\n"
  46                      "    jmp  2b\n"
  47                      ".previous\n"
  48                      _ASM_EXTABLE(1b, 3b)
  49                      : [err] "=r" (err)
  50                      : "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
  51                      : "memory");
  52
  53         return err;
  54 }
  55
  56 static inline int xsave_user(struct xsave_struct __user *buf)
  57 {
  58         int err;
  59         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
  60                              "2:\n"
  61                              ".section .fixup,\"ax\"\n"
  62                              "3:  movl $-1,%[err]\n"
  63                              "    jmp  2b\n"
  64                              ".previous\n"
  65                              ".section __ex_table,\"a\"\n"
  66                              _ASM_ALIGN "\n"
  67                              _ASM_PTR "1b,3b\n"
  68                              ".previous"
  69                              : [err] "=r" (err)
  70                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
  71                              : "memory");
  72         if (unlikely(err) && __clear_user(buf, xstate_size))
  73                 err = -EFAULT;
  74         /* No need to clear here because the caller clears USED_MATH */
  75         return err;
  76 }
  77
  78 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
  79 {
  80         int err;
  81         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
  82         u32 lmask = mask;
  83         u32 hmask = mask >> 32;
  84
  85         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
  86                              "2:\n"
  87                              ".section .fixup,\"ax\"\n"
  88                              "3:  movl $-1,%[err]\n"
  89                              "    jmp  2b\n"
  90                              ".previous\n"
  91                              ".section __ex_table,\"a\"\n"
  92                              _ASM_ALIGN "\n"
  93                              _ASM_PTR "1b,3b\n"
  94                              ".previous"
  95                              : [err] "=r" (err)
  96                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
  97                              : "memory");       /* memory required? */
  98         return err;
  99 }
 100
 101 static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
 102 {
 103         u32 lmask = mask;
 104         u32 hmask = mask >> 32;
 105
 106         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
 107                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 108                      :   "memory");
 109 }
 110
 111 static inline void xsave(struct task_struct *tsk)
 112 {
 113         /* This, however, we can work around by forcing the compiler to select
 114            an addressing mode that doesn't require extended registers. */
 115         __asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27"
 116                              : : "D" (&(tsk->thread.xstate->xsave)),
 117                                  "a" (-1), "d"(-1) : "memory");
 118 }
 119 #endif