arch/x86/include/asm/fpu/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 /* The highest xstate bit above (of XSTATE_Hi16_ZMM): */
  19 #define XFEATURES_NR_MAX        8
  20
  21 #define XSTATE_FPSSE    (XSTATE_FP | XSTATE_SSE)
  22 #define XSTATE_AVX512   (XSTATE_OPMASK | XSTATE_ZMM_Hi256 | XSTATE_Hi16_ZMM)
  23 /* Bit 63 of XCR0 is reserved for future expansion */
  24 #define XSTATE_EXTEND_MASK      (~(XSTATE_FPSSE | (1ULL << 63)))
  25
  26 #define FXSAVE_SIZE     512
  27
  28 #define XSAVE_HDR_SIZE      64
  29 #define XSAVE_HDR_OFFSET    FXSAVE_SIZE
  30
  31 #define XSAVE_YMM_SIZE      256
  32 #define XSAVE_YMM_OFFSET    (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
  33
  34 /* Supported features which support lazy state saving */
  35 #define XSTATE_LAZY     (XSTATE_FP | XSTATE_SSE | XSTATE_YMM                  \
  36                         | XSTATE_OPMASK | XSTATE_ZMM_Hi256 | XSTATE_Hi16_ZMM)
  37
  38 /* Supported features which require eager state saving */
  39 #define XSTATE_EAGER    (XSTATE_BNDREGS | XSTATE_BNDCSR)
  40
  41 /* All currently supported features */
  42 #define XCNTXT_MASK     (XSTATE_LAZY | XSTATE_EAGER)
  43
  44 #ifdef CONFIG_X86_64
  45 #define REX_PREFIX      "0x48, "
  46 #else
  47 #define REX_PREFIX
  48 #endif
  49
  50 extern unsigned int xstate_size;
  51 extern u64 xfeatures_mask;
  52 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
  53 extern struct xsave_struct init_xstate_ctx;
  54
  55 extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
  56
  57 /* These macros all use (%edi)/(%rdi) as the single memory argument. */
  58 #define XSAVE           ".byte " REX_PREFIX "0x0f,0xae,0x27"
  59 #define XSAVEOPT        ".byte " REX_PREFIX "0x0f,0xae,0x37"
  60 #define XSAVES          ".byte " REX_PREFIX "0x0f,0xc7,0x2f"
  61 #define XRSTOR          ".byte " REX_PREFIX "0x0f,0xae,0x2f"
  62 #define XRSTORS         ".byte " REX_PREFIX "0x0f,0xc7,0x1f"
  63
  64 #define xstate_fault    ".section .fixup,\"ax\"\n"      \
  65                         "3:  movl $-1,%[err]\n"         \
  66                         "    jmp  2b\n"                 \
  67                         ".previous\n"                   \
  68                         _ASM_EXTABLE(1b, 3b)            \
  69                         : [err] "=r" (err)
  70
  71 /*
  72  * This function is called only during boot time when x86 caps are not set
  73  * up and alternative can not be used yet.
  74  */
  75 static inline int xsave_state_booting(struct xsave_struct *fx)
  76 {
  77         u64 mask = -1;
  78         u32 lmask = mask;
  79         u32 hmask = mask >> 32;
  80         int err = 0;
  81
  82         WARN_ON(system_state != SYSTEM_BOOTING);
  83
  84         if (boot_cpu_has(X86_FEATURE_XSAVES))
  85                 asm volatile("1:"XSAVES"\n\t"
  86                         "2:\n\t"
  87                              xstate_fault
  88                         : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
  89                         :   "memory");
  90         else
  91                 asm volatile("1:"XSAVE"\n\t"
  92                         "2:\n\t"
  93                              xstate_fault
  94                         : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
  95                         :   "memory");
  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                              xstate_fault
 115                         : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 116                         :   "memory");
 117         else
 118                 asm volatile("1:"XRSTOR"\n\t"
 119                         "2:\n\t"
 120                              xstate_fault
 121                         : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 122                         :   "memory");
 123         return err;
 124 }
 125
 126 /*
 127  * Save processor xstate to xsave area.
 128  */
 129 static inline int xsave_state(struct xsave_struct *fx)
 130 {
 131         u64 mask = -1;
 132         u32 lmask = mask;
 133         u32 hmask = mask >> 32;
 134         int err = 0;
 135
 136         WARN_ON(system_state == SYSTEM_BOOTING);
 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                 XSAVEOPT,
 152                 X86_FEATURE_XSAVEOPT,
 153                 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                 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  * Restore xstate context for new process during context switch.
 195  */
 196 static inline int fpu_xrstor_checking(struct xsave_struct *fx)
 197 {
 198         return xrstor_state(fx, -1);
 199 }
 200
 201 /*
 202  * Save xstate to user space xsave area.
 203  *
 204  * We don't use modified optimization because xrstor/xrstors might track
 205  * a different application.
 206  *
 207  * We don't use compacted format xsave area for
 208  * backward compatibility for old applications which don't understand
 209  * compacted format of xsave area.
 210  */
 211 static inline int xsave_user(struct xsave_struct __user *buf)
 212 {
 213         int err;
 214
 215         /*
 216          * Clear the xsave header first, so that reserved fields are
 217          * initialized to zero.
 218          */
 219         err = __clear_user(&buf->header, sizeof(buf->header));
 220         if (unlikely(err))
 221                 return -EFAULT;
 222
 223         __asm__ __volatile__(ASM_STAC "\n"
 224                              "1:"XSAVE"\n"
 225                              "2: " ASM_CLAC "\n"
 226                              xstate_fault
 227                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
 228                              : "memory");
 229         return err;
 230 }
 231
 232 /*
 233  * Restore xstate from user space xsave area.
 234  */
 235 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
 236 {
 237         int err = 0;
 238         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
 239         u32 lmask = mask;
 240         u32 hmask = mask >> 32;
 241
 242         __asm__ __volatile__(ASM_STAC "\n"
 243                              "1:"XRSTOR"\n"
 244                              "2: " ASM_CLAC "\n"
 245                              xstate_fault
 246                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
 247                              : "memory");       /* memory required? */
 248         return err;
 249 }
 250
 251 void *get_xsave_addr(struct xsave_struct *xsave, int xstate);
 252 void setup_xstate_comp(void);
 253
 254 #endif