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 XSTATE_YMM_SIZE 256
  17 #define XSTATE_YMM_OFFSET (512 + 64)
  18
  19 /*
  20  * These are the features that the OS can handle currently.
  21  */
  22 #define XCNTXT_MASK     (XSTATE_FP | XSTATE_SSE | XSTATE_YMM)
  23
  24 #ifdef CONFIG_X86_64
  25 #define REX_PREFIX      "0x48, "
  26 #else
  27 #define REX_PREFIX
  28 #endif
  29
  30 extern unsigned int xstate_size;
  31 extern u64 pcntxt_mask;
  32 extern struct xsave_struct *init_xstate_buf;
  33 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
  34
  35 extern void xsave_cntxt_init(void);
  36 extern void xsave_init(void);
  37 extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
  38 extern int init_fpu(struct task_struct *child);
  39 extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
  40                             void __user *fpstate,
  41                             struct _fpx_sw_bytes *sw);
  42
  43 static inline int fpu_xrstor_checking(struct fpu *fpu)
  44 {
  45         struct xsave_struct *fx = &fpu->state->xsave;
  46         int err;
  47
  48         asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
  49                      "2:\n"
  50                      ".section .fixup,\"ax\"\n"
  51                      "3:  movl $-1,%[err]\n"
  52                      "    jmp  2b\n"
  53                      ".previous\n"
  54                      _ASM_EXTABLE(1b, 3b)
  55                      : [err] "=r" (err)
  56                      : "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
  57                      : "memory");
  58
  59         return err;
  60 }
  61
  62 static inline int xsave_user(struct xsave_struct __user *buf)
  63 {
  64         int err;
  65         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
  66                              "2:\n"
  67                              ".section .fixup,\"ax\"\n"
  68                              "3:  movl $-1,%[err]\n"
  69                              "    jmp  2b\n"
  70                              ".previous\n"
  71                              ".section __ex_table,\"a\"\n"
  72                              _ASM_ALIGN "\n"
  73                              _ASM_PTR "1b,3b\n"
  74                              ".previous"
  75                              : [err] "=r" (err)
  76                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
  77                              : "memory");
  78         if (unlikely(err) && __clear_user(buf, xstate_size))
  79                 err = -EFAULT;
  80         /* No need to clear here because the caller clears USED_MATH */
  81         return err;
  82 }
  83
  84 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
  85 {
  86         int err;
  87         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
  88         u32 lmask = mask;
  89         u32 hmask = mask >> 32;
  90
  91         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
  92                              "2:\n"
  93                              ".section .fixup,\"ax\"\n"
  94                              "3:  movl $-1,%[err]\n"
  95                              "    jmp  2b\n"
  96                              ".previous\n"
  97                              ".section __ex_table,\"a\"\n"
  98                              _ASM_ALIGN "\n"
  99                              _ASM_PTR "1b,3b\n"
 100                              ".previous"
 101                              : [err] "=r" (err)
 102                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
 103                              : "memory");       /* memory required? */
 104         return err;
 105 }
 106
 107 static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
 108 {
 109         u32 lmask = mask;
 110         u32 hmask = mask >> 32;
 111
 112         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
 113                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 114                      :   "memory");
 115 }
 116
 117 static inline void fpu_xsave(struct fpu *fpu)
 118 {
 119         /* This, however, we can work around by forcing the compiler to select
 120            an addressing mode that doesn't require extended registers. */
 121         __asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27"
 122                              : : "D" (&(fpu->state->xsave)),
 123                                  "a" (-1), "d"(-1) : "memory");
 124 }
 125 #endif