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 #define XSAVE_HDR_SIZE      64
  17 #define XSAVE_HDR_OFFSET    FXSAVE_SIZE
  18
  19 #define XSAVE_YMM_SIZE      256
  20 #define XSAVE_YMM_OFFSET    (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
  21
  22 /*
  23  * These are the features that the OS can handle currently.
  24  */
  25 #define XCNTXT_MASK     (XSTATE_FP | XSTATE_SSE | XSTATE_YMM)
  26
  27 #ifdef CONFIG_X86_64
  28 #define REX_PREFIX      "0x48, "
  29 #else
  30 #define REX_PREFIX
  31 #endif
  32
  33 extern unsigned int xstate_size;
  34 extern u64 pcntxt_mask;
  35 extern struct xsave_struct *init_xstate_buf;
  36 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
  37
  38 extern void xsave_cntxt_init(void);
  39 extern void xsave_init(void);
  40 extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
  41 extern int init_fpu(struct task_struct *child);
  42 extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
  43                             void __user *fpstate,
  44                             struct _fpx_sw_bytes *sw);
  45
  46 static inline int fpu_xrstor_checking(struct fpu *fpu)
  47 {
  48         struct xsave_struct *fx = &fpu->state->xsave;
  49         int err;
  50
  51         asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
  52                      "2:\n"
  53                      ".section .fixup,\"ax\"\n"
  54                      "3:  movl $-1,%[err]\n"
  55                      "    jmp  2b\n"
  56                      ".previous\n"
  57                      _ASM_EXTABLE(1b, 3b)
  58                      : [err] "=r" (err)
  59                      : "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
  60                      : "memory");
  61
  62         return err;
  63 }
  64
  65 static inline int xsave_user(struct xsave_struct __user *buf)
  66 {
  67         int err;
  68         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
  69                              "2:\n"
  70                              ".section .fixup,\"ax\"\n"
  71                              "3:  movl $-1,%[err]\n"
  72                              "    jmp  2b\n"
  73                              ".previous\n"
  74                              ".section __ex_table,\"a\"\n"
  75                              _ASM_ALIGN "\n"
  76                              _ASM_PTR "1b,3b\n"
  77                              ".previous"
  78                              : [err] "=r" (err)
  79                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
  80                              : "memory");
  81         if (unlikely(err) && __clear_user(buf, xstate_size))
  82                 err = -EFAULT;
  83         /* No need to clear here because the caller clears USED_MATH */
  84         return err;
  85 }
  86
  87 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
  88 {
  89         int err;
  90         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
  91         u32 lmask = mask;
  92         u32 hmask = mask >> 32;
  93
  94         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
  95                              "2:\n"
  96                              ".section .fixup,\"ax\"\n"
  97                              "3:  movl $-1,%[err]\n"
  98                              "    jmp  2b\n"
  99                              ".previous\n"
 100                              ".section __ex_table,\"a\"\n"
 101                              _ASM_ALIGN "\n"
 102                              _ASM_PTR "1b,3b\n"
 103                              ".previous"
 104                              : [err] "=r" (err)
 105                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
 106                              : "memory");       /* memory required? */
 107         return err;
 108 }
 109
 110 static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
 111 {
 112         u32 lmask = mask;
 113         u32 hmask = mask >> 32;
 114
 115         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
 116                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 117                      :   "memory");
 118 }
 119
 120 static inline void fpu_xsave(struct fpu *fpu)
 121 {
 122         /* This, however, we can work around by forcing the compiler to select
 123            an addressing mode that doesn't require extended registers. */
 124         __asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27"
 125                              : : "D" (&(fpu->state->xsave)),
 126                                  "a" (-1), "d"(-1) : "memory");
 127 }
 128 #endif