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
  63         /*
  64          * Clear the xsave header first, so that reserved fields are
  65          * initialized to zero.
  66          */
  67         err = __clear_user(&buf->xsave_hdr,
  68                            sizeof(struct xsave_hdr_struct));
  69         if (unlikely(err))
  70                 return -EFAULT;
  71
  72         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
  73                              "2:\n"
  74                              ".section .fixup,\"ax\"\n"
  75                              "3:  movl $-1,%[err]\n"
  76                              "    jmp  2b\n"
  77                              ".previous\n"
  78                              ".section __ex_table,\"a\"\n"
  79                              _ASM_ALIGN "\n"
  80                              _ASM_PTR "1b,3b\n"
  81                              ".previous"
  82                              : [err] "=r" (err)
  83                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
  84                              : "memory");
  85         if (unlikely(err) && __clear_user(buf, xstate_size))
  86                 err = -EFAULT;
  87         /* No need to clear here because the caller clears USED_MATH */
  88         return err;
  89 }
  90
  91 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
  92 {
  93         int err;
  94         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
  95         u32 lmask = mask;
  96         u32 hmask = mask >> 32;
  97
  98         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
  99                              "2:\n"
 100                              ".section .fixup,\"ax\"\n"
 101                              "3:  movl $-1,%[err]\n"
 102                              "    jmp  2b\n"
 103                              ".previous\n"
 104                              ".section __ex_table,\"a\"\n"
 105                              _ASM_ALIGN "\n"
 106                              _ASM_PTR "1b,3b\n"
 107                              ".previous"
 108                              : [err] "=r" (err)
 109                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
 110                              : "memory");       /* memory required? */
 111         return err;
 112 }
 113
 114 static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
 115 {
 116         u32 lmask = mask;
 117         u32 hmask = mask >> 32;
 118
 119         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
 120                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 121                      :   "memory");
 122 }
 123
 124 static inline void fpu_xsave(struct fpu *fpu)
 125 {
 126         /* This, however, we can work around by forcing the compiler to select
 127            an addressing mode that doesn't require extended registers. */
 128         __asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27"
 129                              : : "D" (&(fpu->state->xsave)),
 130                                  "a" (-1), "d"(-1) : "memory");
 131 }
 132 #endif