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 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
  31
  32 extern void xsave_cntxt_init(void);
  33 extern void xsave_init(void);
  34 extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
  35 extern int init_fpu(struct task_struct *child);
  36 extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
  37                             void __user *fpstate,
  38                             struct _fpx_sw_bytes *sw);
  39
  40 static inline int fpu_xrstor_checking(struct fpu *fpu)
  41 {
  42         struct xsave_struct *fx = &fpu->state->xsave;
  43         int err;
  44
  45         asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
  46                      "2:\n"
  47                      ".section .fixup,\"ax\"\n"
  48                      "3:  movl $-1,%[err]\n"
  49                      "    jmp  2b\n"
  50                      ".previous\n"
  51                      _ASM_EXTABLE(1b, 3b)
  52                      : [err] "=r" (err)
  53                      : "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
  54                      : "memory");
  55
  56         return err;
  57 }
  58
  59 static inline int xsave_user(struct xsave_struct __user *buf)
  60 {
  61         int err;
  62         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
  63                              "2:\n"
  64                              ".section .fixup,\"ax\"\n"
  65                              "3:  movl $-1,%[err]\n"
  66                              "    jmp  2b\n"
  67                              ".previous\n"
  68                              ".section __ex_table,\"a\"\n"
  69                              _ASM_ALIGN "\n"
  70                              _ASM_PTR "1b,3b\n"
  71                              ".previous"
  72                              : [err] "=r" (err)
  73                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
  74                              : "memory");
  75         if (unlikely(err) && __clear_user(buf, xstate_size))
  76                 err = -EFAULT;
  77         /* No need to clear here because the caller clears USED_MATH */
  78         return err;
  79 }
  80
  81 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
  82 {
  83         int err;
  84         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
  85         u32 lmask = mask;
  86         u32 hmask = mask >> 32;
  87
  88         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
  89                              "2:\n"
  90                              ".section .fixup,\"ax\"\n"
  91                              "3:  movl $-1,%[err]\n"
  92                              "    jmp  2b\n"
  93                              ".previous\n"
  94                              ".section __ex_table,\"a\"\n"
  95                              _ASM_ALIGN "\n"
  96                              _ASM_PTR "1b,3b\n"
  97                              ".previous"
  98                              : [err] "=r" (err)
  99                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
 100                              : "memory");       /* memory required? */
 101         return err;
 102 }
 103
 104 static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
 105 {
 106         u32 lmask = mask;
 107         u32 hmask = mask >> 32;
 108
 109         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
 110                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 111                      :   "memory");
 112 }
 113
 114 static inline void fpu_xsave(struct fpu *fpu)
 115 {
 116         /* This, however, we can work around by forcing the compiler to select
 117            an addressing mode that doesn't require extended registers. */
 118         __asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27"
 119                              : : "D" (&(fpu->state->xsave)),
 120                                  "a" (-1), "d"(-1) : "memory");
 121 }
 122 #endif