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
   7 #define XSTATE_CPUID            0x0000000d
   8
   9 #define XSTATE_FP       0x1
  10 #define XSTATE_SSE      0x2
  11 #define XSTATE_YMM      0x4
  12
  13 #define XSTATE_FPSSE    (XSTATE_FP | XSTATE_SSE)
  14
  15 #define FXSAVE_SIZE     512
  16
  17 #define XSAVE_HDR_SIZE      64
  18 #define XSAVE_HDR_OFFSET    FXSAVE_SIZE
  19
  20 #define XSAVE_YMM_SIZE      256
  21 #define XSAVE_YMM_OFFSET    (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
  22
  23 /*
  24  * These are the features that the OS can handle currently.
  25  */
  26 #define XCNTXT_MASK     (XSTATE_FP | XSTATE_SSE | XSTATE_YMM)
  27
  28 #ifdef CONFIG_X86_64
  29 #define REX_PREFIX      "0x48, "
  30 #else
  31 #define REX_PREFIX
  32 #endif
  33
  34 extern unsigned int xstate_size;
  35 extern u64 pcntxt_mask;
  36 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
  37 extern struct xsave_struct *init_xstate_buf;
  38
  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
  43 static inline int fpu_xrstor_checking(struct xsave_struct *fx)
  44 {
  45         int err;
  46
  47         asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
  48                      "2:\n"
  49                      ".section .fixup,\"ax\"\n"
  50                      "3:  movl $-1,%[err]\n"
  51                      "    jmp  2b\n"
  52                      ".previous\n"
  53                      _ASM_EXTABLE(1b, 3b)
  54                      : [err] "=r" (err)
  55                      : "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
  56                      : "memory");
  57
  58         return err;
  59 }
  60
  61 static inline int xsave_user(struct xsave_struct __user *buf)
  62 {
  63         int err;
  64
  65         /*
  66          * Clear the xsave header first, so that reserved fields are
  67          * initialized to zero.
  68          */
  69         err = __clear_user(&buf->xsave_hdr, sizeof(buf->xsave_hdr));
  70         if (unlikely(err))
  71                 return -EFAULT;
  72
  73         __asm__ __volatile__(ASM_STAC "\n"
  74                              "1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
  75                              "2: " ASM_CLAC "\n"
  76                              ".section .fixup,\"ax\"\n"
  77                              "3:  movl $-1,%[err]\n"
  78                              "    jmp  2b\n"
  79                              ".previous\n"
  80                              _ASM_EXTABLE(1b,3b)
  81                              : [err] "=r" (err)
  82                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
  83                              : "memory");
  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__(ASM_STAC "\n"
  95                              "1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
  96                              "2: " ASM_CLAC "\n"
  97                              ".section .fixup,\"ax\"\n"
  98                              "3:  movl $-1,%[err]\n"
  99                              "    jmp  2b\n"
 100                              ".previous\n"
 101                              _ASM_EXTABLE(1b,3b)
 102                              : [err] "=r" (err)
 103                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
 104                              : "memory");       /* memory required? */
 105         return err;
 106 }
 107
 108 static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
 109 {
 110         u32 lmask = mask;
 111         u32 hmask = mask >> 32;
 112
 113         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
 114                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 115                      :   "memory");
 116 }
 117
 118 static inline void xsave_state(struct xsave_struct *fx, u64 mask)
 119 {
 120         u32 lmask = mask;
 121         u32 hmask = mask >> 32;
 122
 123         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x27\n\t"
 124                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 125                      :   "memory");
 126 }
 127
 128 static inline void fpu_xsave(struct fpu *fpu)
 129 {
 130         /* This, however, we can work around by forcing the compiler to select
 131            an addressing mode that doesn't require extended registers. */
 132         alternative_input(
 133                 ".byte " REX_PREFIX "0x0f,0xae,0x27",
 134                 ".byte " REX_PREFIX "0x0f,0xae,0x37",
 135                 X86_FEATURE_XSAVEOPT,
 136                 [fx] "D" (&fpu->state->xsave), "a" (-1), "d" (-1) :
 137                 "memory");
 138 }
 139 #endif