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 /* These macros all use (%edi)/(%rdi) as the single memory argument. */
  56 #define XSAVE           ".byte " REX_PREFIX "0x0f,0xae,0x27"
  57 #define XSAVEOPT        ".byte " REX_PREFIX "0x0f,0xae,0x37"
  58 #define XSAVES          ".byte " REX_PREFIX "0x0f,0xc7,0x2f"
  59 #define XRSTOR          ".byte " REX_PREFIX "0x0f,0xae,0x2f"
  60 #define XRSTORS         ".byte " REX_PREFIX "0x0f,0xc7,0x1f"
  61
  62 #define xstate_fault    ".section .fixup,\"ax\"\n"      \
  63                         "3:  movl $-1,%[err]\n"         \
  64                         "    jmp  2b\n"                 \
  65                         ".previous\n"                   \
  66                         _ASM_EXTABLE(1b, 3b)            \
  67                         : [err] "=r" (err)
  68
  69 /*
  70  * This function is called only during boot time when x86 caps are not set
  71  * up and alternative can not be used yet.
  72  */
  73 static inline int xsave_state_booting(struct xsave_struct *fx, u64 mask)
  74 {
  75         u32 lmask = mask;
  76         u32 hmask = mask >> 32;
  77         int err = 0;
  78
  79         WARN_ON(system_state != SYSTEM_BOOTING);
  80
  81         if (boot_cpu_has(X86_FEATURE_XSAVES))
  82                 asm volatile("1:"XSAVES"\n\t"
  83                         "2:\n\t"
  84                         : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
  85                         :   "memory");
  86         else
  87                 asm volatile("1:"XSAVE"\n\t"
  88                         "2:\n\t"
  89                         : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
  90                         :   "memory");
  91
  92         asm volatile(xstate_fault
  93                      : "0" (0)
  94                      : "memory");
  95
  96         return err;
  97 }
  98
  99 /*
 100  * This function is called only during boot time when x86 caps are not set
 101  * up and alternative can not be used yet.
 102  */
 103 static inline int xrstor_state_booting(struct xsave_struct *fx, u64 mask)
 104 {
 105         u32 lmask = mask;
 106         u32 hmask = mask >> 32;
 107         int err = 0;
 108
 109         WARN_ON(system_state != SYSTEM_BOOTING);
 110
 111         if (boot_cpu_has(X86_FEATURE_XSAVES))
 112                 asm volatile("1:"XRSTORS"\n\t"
 113                         "2:\n\t"
 114                         : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 115                         :   "memory");
 116         else
 117                 asm volatile("1:"XRSTOR"\n\t"
 118                         "2:\n\t"
 119                         : : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 120                         :   "memory");
 121
 122         asm volatile(xstate_fault
 123                      : "0" (0)
 124                      : "memory");
 125
 126         return err;
 127 }
 128
 129 /*
 130  * Save processor xstate to xsave area.
 131  */
 132 static inline int xsave_state(struct xsave_struct *fx, u64 mask)
 133 {
 134         u32 lmask = mask;
 135         u32 hmask = mask >> 32;
 136         int err = 0;
 137
 138         /*
 139          * If xsaves is enabled, xsaves replaces xsaveopt because
 140          * it supports compact format and supervisor states in addition to
 141          * modified optimization in xsaveopt.
 142          *
 143          * Otherwise, if xsaveopt is enabled, xsaveopt replaces xsave
 144          * because xsaveopt supports modified optimization which is not
 145          * supported by xsave.
 146          *
 147          * If none of xsaves and xsaveopt is enabled, use xsave.
 148          */
 149         alternative_input_2(
 150                 "1:"XSAVE,
 151                 "1:"XSAVEOPT,
 152                 X86_FEATURE_XSAVEOPT,
 153                 "1:"XSAVES,
 154                 X86_FEATURE_XSAVES,
 155                 [fx] "D" (fx), "a" (lmask), "d" (hmask) :
 156                 "memory");
 157         asm volatile("2:\n\t"
 158                      xstate_fault
 159                      : "0" (0)
 160                      : "memory");
 161
 162         return err;
 163 }
 164
 165 /*
 166  * Restore processor xstate from xsave area.
 167  */
 168 static inline int xrstor_state(struct xsave_struct *fx, u64 mask)
 169 {
 170         int err = 0;
 171         u32 lmask = mask;
 172         u32 hmask = mask >> 32;
 173
 174         /*
 175          * Use xrstors to restore context if it is enabled. xrstors supports
 176          * compacted format of xsave area which is not supported by xrstor.
 177          */
 178         alternative_input(
 179                 "1: " XRSTOR,
 180                 "1: " XRSTORS,
 181                 X86_FEATURE_XSAVES,
 182                 "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 183                 : "memory");
 184
 185         asm volatile("2:\n"
 186                      xstate_fault
 187                      : "0" (0)
 188                      : "memory");
 189
 190         return err;
 191 }
 192
 193 /*
 194  * Save xstate context for old process during context switch.
 195  */
 196 static inline void fpu_xsave(struct fpu *fpu)
 197 {
 198         xsave_state(&fpu->state->xsave, -1);
 199 }
 200
 201 /*
 202  * Restore xstate context for new process during context switch.
 203  */
 204 static inline int fpu_xrstor_checking(struct xsave_struct *fx)
 205 {
 206         return xrstor_state(fx, -1);
 207 }
 208
 209 /*
 210  * Save xstate to user space xsave area.
 211  *
 212  * We don't use modified optimization because xrstor/xrstors might track
 213  * a different application.
 214  *
 215  * We don't use compacted format xsave area for
 216  * backward compatibility for old applications which don't understand
 217  * compacted format of xsave area.
 218  */
 219 static inline int xsave_user(struct xsave_struct __user *buf)
 220 {
 221         int err;
 222
 223         /*
 224          * Clear the xsave header first, so that reserved fields are
 225          * initialized to zero.
 226          */
 227         err = __clear_user(&buf->xsave_hdr, sizeof(buf->xsave_hdr));
 228         if (unlikely(err))
 229                 return -EFAULT;
 230
 231         __asm__ __volatile__(ASM_STAC "\n"
 232                              "1:"XSAVE"\n"
 233                              "2: " ASM_CLAC "\n"
 234                              xstate_fault
 235                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
 236                              : "memory");
 237         return err;
 238 }
 239
 240 /*
 241  * Restore xstate from user space xsave area.
 242  */
 243 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
 244 {
 245         int err = 0;
 246         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
 247         u32 lmask = mask;
 248         u32 hmask = mask >> 32;
 249
 250         __asm__ __volatile__(ASM_STAC "\n"
 251                              "1:"XRSTOR"\n"
 252                              "2: " ASM_CLAC "\n"
 253                              xstate_fault
 254                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
 255                              : "memory");       /* memory required? */
 256         return err;
 257 }
 258
 259 void *get_xsave_addr(struct xsave_struct *xsave, int xstate);
 260 void setup_xstate_comp(void);
 261
 262 #endif