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
  38 extern void xsave_init(void);
  39 extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
  40 extern int init_fpu(struct task_struct *child);
  41 extern int check_for_xstate(struct i387_fxsave_struct __user *buf,
  42                             void __user *fpstate,
  43                             struct _fpx_sw_bytes *sw);
  44
  45 static inline int fpu_xrstor_checking(struct fpu *fpu)
  46 {
  47         struct xsave_struct *fx = &fpu->state->xsave;
  48         int err;
  49
  50         asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
  51                      "2:\n"
  52                      ".section .fixup,\"ax\"\n"
  53                      "3:  movl $-1,%[err]\n"
  54                      "    jmp  2b\n"
  55                      ".previous\n"
  56                      _ASM_EXTABLE(1b, 3b)
  57                      : [err] "=r" (err)
  58                      : "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
  59                      : "memory");
  60
  61         return err;
  62 }
  63
  64 static inline int xsave_user(struct xsave_struct __user *buf)
  65 {
  66         int err;
  67
  68         /*
  69          * Clear the xsave header first, so that reserved fields are
  70          * initialized to zero.
  71          */
  72         err = __clear_user(&buf->xsave_hdr,
  73                            sizeof(struct xsave_hdr_struct));
  74         if (unlikely(err))
  75                 return -EFAULT;
  76
  77         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
  78                              "2:\n"
  79                              ".section .fixup,\"ax\"\n"
  80                              "3:  movl $-1,%[err]\n"
  81                              "    jmp  2b\n"
  82                              ".previous\n"
  83                              _ASM_EXTABLE(1b,3b)
  84                              : [err] "=r" (err)
  85                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
  86                              : "memory");
  87         if (unlikely(err) && __clear_user(buf, xstate_size))
  88                 err = -EFAULT;
  89         /* No need to clear here because the caller clears USED_MATH */
  90         return err;
  91 }
  92
  93 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
  94 {
  95         int err;
  96         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
  97         u32 lmask = mask;
  98         u32 hmask = mask >> 32;
  99
 100         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
 101                              "2:\n"
 102                              ".section .fixup,\"ax\"\n"
 103                              "3:  movl $-1,%[err]\n"
 104                              "    jmp  2b\n"
 105                              ".previous\n"
 106                              _ASM_EXTABLE(1b,3b)
 107                              : [err] "=r" (err)
 108                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
 109                              : "memory");       /* memory required? */
 110         return err;
 111 }
 112
 113 static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
 114 {
 115         u32 lmask = mask;
 116         u32 hmask = mask >> 32;
 117
 118         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
 119                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 120                      :   "memory");
 121 }
 122
 123 static inline void xsave_state(struct xsave_struct *fx, u64 mask)
 124 {
 125         u32 lmask = mask;
 126         u32 hmask = mask >> 32;
 127
 128         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x27\n\t"
 129                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 130                      :   "memory");
 131 }
 132
 133 static inline void fpu_xsave(struct fpu *fpu)
 134 {
 135         /* This, however, we can work around by forcing the compiler to select
 136            an addressing mode that doesn't require extended registers. */
 137         alternative_input(
 138                 ".byte " REX_PREFIX "0x0f,0xae,0x27",
 139                 ".byte " REX_PREFIX "0x0f,0xae,0x37",
 140                 X86_FEATURE_XSAVEOPT,
 141                 [fx] "D" (&fpu->state->xsave), "a" (-1), "d" (-1) :
 142                 "memory");
 143 }
 144 #endif