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 #define XSTATE_AVX512   (XSTATE_OPMASK | XSTATE_ZMM_Hi256 | XSTATE_Hi16_ZMM)
  20 /* Bit 63 of XCR0 is reserved for future expansion */
  21 #define XSTATE_EXTEND_MASK      (~(XSTATE_FPSSE | (1ULL << 63)))
  22
  23 #define FXSAVE_SIZE     512
  24
  25 #define XSAVE_HDR_SIZE      64
  26 #define XSAVE_HDR_OFFSET    FXSAVE_SIZE
  27
  28 #define XSAVE_YMM_SIZE      256
  29 #define XSAVE_YMM_OFFSET    (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
  30
  31 /* Supported features which support lazy state saving */
  32 #define XSTATE_LAZY     (XSTATE_FP | XSTATE_SSE | XSTATE_YMM                  \
  33                         | XSTATE_OPMASK | XSTATE_ZMM_Hi256 | XSTATE_Hi16_ZMM)
  34
  35 /* Supported features which require eager state saving */
  36 #define XSTATE_EAGER    (XSTATE_BNDREGS | XSTATE_BNDCSR)
  37
  38 /* All currently supported features */
  39 #define XCNTXT_MASK     (XSTATE_LAZY | XSTATE_EAGER)
  40
  41 #ifdef CONFIG_X86_64
  42 #define REX_PREFIX      "0x48, "
  43 #else
  44 #define REX_PREFIX
  45 #endif
  46
  47 extern unsigned int xstate_size;
  48 extern u64 pcntxt_mask;
  49 extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
  50 extern struct xsave_struct *init_xstate_buf;
  51
  52 extern void xsave_init(void);
  53 extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
  54 extern int init_fpu(struct task_struct *child);
  55
  56 /* These macros all use (%edi)/(%rdi) as the single memory argument. */
  57 #define XSAVE           ".byte " REX_PREFIX "0x0f,0xae,0x27"
  58 #define XSAVEOPT        ".byte " REX_PREFIX "0x0f,0xae,0x37"
  59 #define XSAVES          ".byte " REX_PREFIX "0x0f,0xc7,0x2f"
  60 #define XRSTOR          ".byte " REX_PREFIX "0x0f,0xae,0x2f"
  61 #define XRSTORS         ".byte " REX_PREFIX "0x0f,0xc7,0x1f"
  62
  63 #define xstate_fault    ".section .fixup,\"ax\"\n"      \
  64                         "3:  movl $-1,%[err]\n"         \
  65                         "    jmp  2b\n"                 \
  66                         ".previous\n"                   \
  67                         _ASM_EXTABLE(1b, 3b)            \
  68                         : [err] "=r" (err)
  69
  70 /*
  71  * This function is called only during boot time when x86 caps are not set
  72  * up and alternative can not be used yet.
  73  */
  74 static inline int xsave_state_booting(struct xsave_struct *fx, u64 mask)
  75 {
  76         u32 lmask = mask;
  77         u32 hmask = mask >> 32;
  78         int err = 0;
  79
  80         WARN_ON(system_state != SYSTEM_BOOTING);
  81
  82         if (boot_cpu_has(X86_FEATURE_XSAVES))
  83                 asm volatile("1:"XSAVES"\n\t"
  84                         "2:\n\t"
  85                              xstate_fault
  86                         : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
  87                         :   "memory");
  88         else
  89                 asm volatile("1:"XSAVE"\n\t"
  90                         "2:\n\t"
  91                              xstate_fault
  92                         : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
  93                         :   "memory");
  94         return err;
  95 }
  96
  97 /*
  98  * This function is called only during boot time when x86 caps are not set
  99  * up and alternative can not be used yet.
 100  */
 101 static inline int xrstor_state_booting(struct xsave_struct *fx, u64 mask)
 102 {
 103         u32 lmask = mask;
 104         u32 hmask = mask >> 32;
 105         int err = 0;
 106
 107         WARN_ON(system_state != SYSTEM_BOOTING);
 108
 109         if (boot_cpu_has(X86_FEATURE_XSAVES))
 110                 asm volatile("1:"XRSTORS"\n\t"
 111                         "2:\n\t"
 112                              xstate_fault
 113                         : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 114                         :   "memory");
 115         else
 116                 asm volatile("1:"XRSTOR"\n\t"
 117                         "2:\n\t"
 118                              xstate_fault
 119                         : "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 120                         :   "memory");
 121         return err;
 122 }
 123
 124 /*
 125  * Save processor xstate to xsave area.
 126  */
 127 static inline int xsave_state(struct xsave_struct *fx, u64 mask)
 128 {
 129         u32 lmask = mask;
 130         u32 hmask = mask >> 32;
 131         int err = 0;
 132
 133         /*
 134          * If xsaves is enabled, xsaves replaces xsaveopt because
 135          * it supports compact format and supervisor states in addition to
 136          * modified optimization in xsaveopt.
 137          *
 138          * Otherwise, if xsaveopt is enabled, xsaveopt replaces xsave
 139          * because xsaveopt supports modified optimization which is not
 140          * supported by xsave.
 141          *
 142          * If none of xsaves and xsaveopt is enabled, use xsave.
 143          */
 144         alternative_input_2(
 145                 "1:"XSAVE,
 146                 XSAVEOPT,
 147                 X86_FEATURE_XSAVEOPT,
 148                 XSAVES,
 149                 X86_FEATURE_XSAVES,
 150                 [fx] "D" (fx), "a" (lmask), "d" (hmask) :
 151                 "memory");
 152         asm volatile("2:\n\t"
 153                      xstate_fault
 154                      : "0" (0)
 155                      : "memory");
 156
 157         return err;
 158 }
 159
 160 /*
 161  * Restore processor xstate from xsave area.
 162  */
 163 static inline int xrstor_state(struct xsave_struct *fx, u64 mask)
 164 {
 165         int err = 0;
 166         u32 lmask = mask;
 167         u32 hmask = mask >> 32;
 168
 169         /*
 170          * Use xrstors to restore context if it is enabled. xrstors supports
 171          * compacted format of xsave area which is not supported by xrstor.
 172          */
 173         alternative_input(
 174                 "1: " XRSTOR,
 175                 XRSTORS,
 176                 X86_FEATURE_XSAVES,
 177                 "D" (fx), "m" (*fx), "a" (lmask), "d" (hmask)
 178                 : "memory");
 179
 180         asm volatile("2:\n"
 181                      xstate_fault
 182                      : "0" (0)
 183                      : "memory");
 184
 185         return err;
 186 }
 187
 188 /*
 189  * Save xstate context for old process during context switch.
 190  */
 191 static inline void fpu_xsave(struct fpu *fpu)
 192 {
 193         xsave_state(&fpu->state->xsave, -1);
 194 }
 195
 196 /*
 197  * Restore xstate context for new process during context switch.
 198  */
 199 static inline int fpu_xrstor_checking(struct xsave_struct *fx)
 200 {
 201         return xrstor_state(fx, -1);
 202 }
 203
 204 /*
 205  * Save xstate to user space xsave area.
 206  *
 207  * We don't use modified optimization because xrstor/xrstors might track
 208  * a different application.
 209  *
 210  * We don't use compacted format xsave area for
 211  * backward compatibility for old applications which don't understand
 212  * compacted format of xsave area.
 213  */
 214 static inline int xsave_user(struct xsave_struct __user *buf)
 215 {
 216         int err;
 217
 218         /*
 219          * Clear the xsave header first, so that reserved fields are
 220          * initialized to zero.
 221          */
 222         err = __clear_user(&buf->xsave_hdr, sizeof(buf->xsave_hdr));
 223         if (unlikely(err))
 224                 return -EFAULT;
 225
 226         __asm__ __volatile__(ASM_STAC "\n"
 227                              "1:"XSAVE"\n"
 228                              "2: " ASM_CLAC "\n"
 229                              xstate_fault
 230                              : "D" (buf), "a" (-1), "d" (-1), "0" (0)
 231                              : "memory");
 232         return err;
 233 }
 234
 235 /*
 236  * Restore xstate from user space xsave area.
 237  */
 238 static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
 239 {
 240         int err = 0;
 241         struct xsave_struct *xstate = ((__force struct xsave_struct *)buf);
 242         u32 lmask = mask;
 243         u32 hmask = mask >> 32;
 244
 245         __asm__ __volatile__(ASM_STAC "\n"
 246                              "1:"XRSTOR"\n"
 247                              "2: " ASM_CLAC "\n"
 248                              xstate_fault
 249                              : "D" (xstate), "a" (lmask), "d" (hmask), "0" (0)
 250                              : "memory");       /* memory required? */
 251         return err;
 252 }
 253
 254 void *get_xsave_addr(struct xsave_struct *xsave, int xstate);
 255 void setup_xstate_comp(void);
 256
 257 #endif