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 #define XSTATE_BNDREGS          0x8
  13 #define XSTATE_BNDCSR           0x10
  14 #define XSTATE_OPMASK           0x20
  15 #define XSTATE_ZMM_Hi256        0x40
  16 #define XSTATE_Hi16_ZMM         0x80
  17
  18 #define XSTATE_FPSSE    (XSTATE_FP | XSTATE_SSE)
  19 /* Bit 63 of XCR0 is reserved for future expansion */
  20 #define XSTATE_EXTEND_MASK      (~(XSTATE_FPSSE | (1ULL << 63)))
  21
  22 #define FXSAVE_SIZE     512
  23
  24 #define XSAVE_HDR_SIZE      64
  25 #define XSAVE_HDR_OFFSET    FXSAVE_SIZE
  26
  27 #define XSAVE_YMM_SIZE      256
  28 #define XSAVE_YMM_OFFSET    (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
  29
  30 /* Supported features which support lazy state saving */
  31 #define XSTATE_LAZY     (XSTATE_FP | XSTATE_SSE | XSTATE_YMM                  \
  32                         | XSTATE_OPMASK | XSTATE_ZMM_Hi256 | XSTATE_Hi16_ZMM)
  33
  34 /* Supported features which require eager state saving */
  35 #define XSTATE_EAGER    (XSTATE_BNDREGS | XSTATE_BNDCSR)
  36
  37 /* All currently supported features */
  38 #define XCNTXT_MASK     (XSTATE_LAZY | XSTATE_EAGER)
  39
  40 #ifdef CONFIG_X86_64
  41 #define REX_PREFIX      "0x48, "
  42 #else
  43 #define REX_PREFIX
  44 #endif
  45
  46 extern unsigned int xstate_size;
  47 extern u64 pcntxt_mask;
  48 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
  49 extern struct xsave_struct *init_xstate_buf;
  50
  51 extern void xsave_init(void);
  52 extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
  53 extern int init_fpu(struct task_struct *child);
  54
  55 static inline int fpu_xrstor_checking(struct xsave_struct *fx)
  56 {
  57         int err;
  58
  59         asm volatile("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
  60                      "2:\n"
  61                      ".section .fixup,\"ax\"\n"
  62                      "3:  movl $-1,%[err]\n"
  63                      "    jmp  2b\n"
  64                      ".previous\n"
  65                      _ASM_EXTABLE(1b, 3b)
  66                      : [err] "=r" (err)
  67                      : "D" (fx), "m" (*fx), "a" (-1), "d" (-1), "0" (0)
  68                      : "memory");
  69
  70         return err;
  71 }
  72
  73 static inline int xsave_user(struct xsave_struct __user *buf)
  74 {
  75         int err;
  76
  77         /*
  78          * Clear the xsave header first, so that reserved fields are
  79          * initialized to zero.
  80          */
  81         err = __clear_user(&buf->xsave_hdr, sizeof(buf->xsave_hdr));
  82         if (unlikely(err))
  83                 return -EFAULT;
  84
  85         __asm__ __volatile__(ASM_STAC "\n"
  86                              "1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
  87                              "2: " ASM_CLAC "\n"
  88                              ".section .fixup,\"ax\"\n"
  89                              "3:  movl $-1,%[err]\n"
  90                              "    jmp  2b\n"
  91                              ".previous\n"
  92                              _ASM_EXTABLE(1b,3b)
  93                              : [err] "=r" (err)
  94                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
  95                              : "memory");
  96         return err;
  97 }
  98
  99 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
 100 {
 101         int err;
 102         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
 103         u32 lmask = mask;
 104         u32 hmask = mask >> 32;
 105
 106         __asm__ __volatile__(ASM_STAC "\n"
 107                              "1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
 108                              "2: " ASM_CLAC "\n"
 109                              ".section .fixup,\"ax\"\n"
 110                              "3:  movl $-1,%[err]\n"
 111                              "    jmp  2b\n"
 112                              ".previous\n"
 113                              _ASM_EXTABLE(1b,3b)
 114                              : [err] "=r" (err)
 115                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
 116                              : "memory");       /* memory required? */
 117         return err;
 118 }
 119
 120 static inline void xrstor_state(struct xsave_struct *fx, u64 mask)
 121 {
 122         u32 lmask = mask;
 123         u32 hmask = mask >> 32;
 124
 125         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x2f\n\t"
 126                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 127                      :   "memory");
 128 }
 129
 130 static inline void xsave_state(struct xsave_struct *fx, u64 mask)
 131 {
 132         u32 lmask = mask;
 133         u32 hmask = mask >> 32;
 134
 135         asm volatile(".byte " REX_PREFIX "0x0f,0xae,0x27\n\t"
 136                      : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 137                      :   "memory");
 138 }
 139
 140 static inline void fpu_xsave(struct fpu *fpu)
 141 {
 142         /* This, however, we can work around by forcing the compiler to select
 143            an addressing mode that doesn't require extended registers. */
 144         alternative_input(
 145                 ".byte " REX_PREFIX "0x0f,0xae,0x27",
 146                 ".byte " REX_PREFIX "0x0f,0xae,0x37",
 147                 X86_FEATURE_XSAVEOPT,
 148                 [fx] "D" (&fpu->state->xsave), "a" (-1), "d" (-1) :
 149                 "memory");
 150 }
 151 #endif