include/asm-i386/paravirt.h

   1 #ifndef __ASM_PARAVIRT_H
   2 #define __ASM_PARAVIRT_H
   3 /* Various instructions on x86 need to be replaced for
   4  * para-virtualization: those hooks are defined here. */
   5 #include <linux/linkage.h>
   6 #include <linux/stringify.h>
   7
   8 #ifdef CONFIG_PARAVIRT
   9 /* These are the most performance critical ops, so we want to be able to patch
  10  * callers */
  11 #define PARAVIRT_IRQ_DISABLE 0
  12 #define PARAVIRT_IRQ_ENABLE 1
  13 #define PARAVIRT_RESTORE_FLAGS 2
  14 #define PARAVIRT_SAVE_FLAGS 3
  15 #define PARAVIRT_SAVE_FLAGS_IRQ_DISABLE 4
  16 #define PARAVIRT_INTERRUPT_RETURN 5
  17 #define PARAVIRT_STI_SYSEXIT 6
  18
  19 /* Bitmask of what can be clobbered: usually at least eax. */
  20 #define CLBR_NONE 0x0
  21 #define CLBR_EAX 0x1
  22 #define CLBR_ECX 0x2
  23 #define CLBR_EDX 0x4
  24 #define CLBR_ANY 0x7
  25
  26 #ifndef __ASSEMBLY__
  27 struct thread_struct;
  28 struct Xgt_desc_struct;
  29 struct tss_struct;
  30 struct paravirt_ops
  31 {
  32         unsigned int kernel_rpl;
  33         int paravirt_enabled;
  34         const char *name;
  35
  36         /*
  37          * Patch may replace one of the defined code sequences with arbitrary
  38          * code, subject to the same register constraints.  This generally
  39          * means the code is not free to clobber any registers other than EAX.
  40          * The patch function should return the number of bytes of code
  41          * generated, as we nop pad the rest in generic code.
  42          */
  43         unsigned (*patch)(u8 type, u16 clobber, void *firstinsn, unsigned len);
  44
  45         void (*arch_setup)(void);
  46         char *(*memory_setup)(void);
  47         void (*init_IRQ)(void);
  48
  49         void (*banner)(void);
  50
  51         unsigned long (*get_wallclock)(void);
  52         int (*set_wallclock)(unsigned long);
  53         void (*time_init)(void);
  54
  55         /* All the function pointers here are declared as "fastcall"
  56            so that we get a specific register-based calling
  57            convention.  This makes it easier to implement inline
  58            assembler replacements. */
  59
  60         void (fastcall *cpuid)(unsigned int *eax, unsigned int *ebx,
  61                       unsigned int *ecx, unsigned int *edx);
  62
  63         unsigned long (fastcall *get_debugreg)(int regno);
  64         void (fastcall *set_debugreg)(int regno, unsigned long value);
  65
  66         void (fastcall *clts)(void);
  67
  68         unsigned long (fastcall *read_cr0)(void);
  69         void (fastcall *write_cr0)(unsigned long);
  70
  71         unsigned long (fastcall *read_cr2)(void);
  72         void (fastcall *write_cr2)(unsigned long);
  73
  74         unsigned long (fastcall *read_cr3)(void);
  75         void (fastcall *write_cr3)(unsigned long);
  76
  77         unsigned long (fastcall *read_cr4_safe)(void);
  78         unsigned long (fastcall *read_cr4)(void);
  79         void (fastcall *write_cr4)(unsigned long);
  80
  81         unsigned long (fastcall *save_fl)(void);
  82         void (fastcall *restore_fl)(unsigned long);
  83         void (fastcall *irq_disable)(void);
  84         void (fastcall *irq_enable)(void);
  85         void (fastcall *safe_halt)(void);
  86         void (fastcall *halt)(void);
  87         void (fastcall *wbinvd)(void);
  88
  89         /* err = 0/-EFAULT.  wrmsr returns 0/-EFAULT. */
  90         u64 (fastcall *read_msr)(unsigned int msr, int *err);
  91         int (fastcall *write_msr)(unsigned int msr, u64 val);
  92
  93         u64 (fastcall *read_tsc)(void);
  94         u64 (fastcall *read_pmc)(void);
  95
  96         void (fastcall *load_tr_desc)(void);
  97         void (fastcall *load_gdt)(const struct Xgt_desc_struct *);
  98         void (fastcall *load_idt)(const struct Xgt_desc_struct *);
  99         void (fastcall *store_gdt)(struct Xgt_desc_struct *);
 100         void (fastcall *store_idt)(struct Xgt_desc_struct *);
 101         void (fastcall *set_ldt)(const void *desc, unsigned entries);
 102         unsigned long (fastcall *store_tr)(void);
 103         void (fastcall *load_tls)(struct thread_struct *t, unsigned int cpu);
 104         void (fastcall *write_ldt_entry)(void *dt, int entrynum,
 105                                          u32 low, u32 high);
 106         void (fastcall *write_gdt_entry)(void *dt, int entrynum,
 107                                          u32 low, u32 high);
 108         void (fastcall *write_idt_entry)(void *dt, int entrynum,
 109                                          u32 low, u32 high);
 110         void (fastcall *load_esp0)(struct tss_struct *tss,
 111                                    struct thread_struct *thread);
 112
 113         void (fastcall *set_iopl_mask)(unsigned mask);
 114
 115         void (fastcall *io_delay)(void);
 116         void (*const_udelay)(unsigned long loops);
 117
 118         /* These two are jmp to, not actually called. */
 119         void (fastcall *irq_enable_sysexit)(void);
 120         void (fastcall *iret)(void);
 121 };
 122
 123 /* Mark a paravirt probe function. */
 124 #define paravirt_probe(fn)                                              \
 125  static asmlinkage void (*__paravirtprobe_##fn)(void) __attribute_used__ \
 126                 __attribute__((__section__(".paravirtprobe"))) = fn
 127
 128 extern struct paravirt_ops paravirt_ops;
 129
 130 #define paravirt_enabled() (paravirt_ops.paravirt_enabled)
 131
 132 static inline void load_esp0(struct tss_struct *tss,
 133                              struct thread_struct *thread)
 134 {
 135         paravirt_ops.load_esp0(tss, thread);
 136 }
 137
 138 #define ARCH_SETUP                      paravirt_ops.arch_setup();
 139 static inline unsigned long get_wallclock(void)
 140 {
 141         return paravirt_ops.get_wallclock();
 142 }
 143
 144 static inline int set_wallclock(unsigned long nowtime)
 145 {
 146         return paravirt_ops.set_wallclock(nowtime);
 147 }
 148
 149 static inline void do_time_init(void)
 150 {
 151         return paravirt_ops.time_init();
 152 }
 153
 154 /* The paravirtualized CPUID instruction. */
 155 static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
 156                            unsigned int *ecx, unsigned int *edx)
 157 {
 158         paravirt_ops.cpuid(eax, ebx, ecx, edx);
 159 }
 160
 161 /*
 162  * These special macros can be used to get or set a debugging register
 163  */
 164 #define get_debugreg(var, reg) var = paravirt_ops.get_debugreg(reg)
 165 #define set_debugreg(val, reg) paravirt_ops.set_debugreg(reg, val)
 166
 167 #define clts() paravirt_ops.clts()
 168
 169 #define read_cr0() paravirt_ops.read_cr0()
 170 #define write_cr0(x) paravirt_ops.write_cr0(x)
 171
 172 #define read_cr2() paravirt_ops.read_cr2()
 173 #define write_cr2(x) paravirt_ops.write_cr2(x)
 174
 175 #define read_cr3() paravirt_ops.read_cr3()
 176 #define write_cr3(x) paravirt_ops.write_cr3(x)
 177
 178 #define read_cr4() paravirt_ops.read_cr4()
 179 #define read_cr4_safe(x) paravirt_ops.read_cr4_safe()
 180 #define write_cr4(x) paravirt_ops.write_cr4(x)
 181
 182 static inline void raw_safe_halt(void)
 183 {
 184         paravirt_ops.safe_halt();
 185 }
 186
 187 static inline void halt(void)
 188 {
 189         paravirt_ops.safe_halt();
 190 }
 191 #define wbinvd() paravirt_ops.wbinvd()
 192
 193 #define get_kernel_rpl()  (paravirt_ops.kernel_rpl)
 194
 195 #define rdmsr(msr,val1,val2) do {                               \
 196         int _err;                                               \
 197         u64 _l = paravirt_ops.read_msr(msr,&_err);              \
 198         val1 = (u32)_l;                                         \
 199         val2 = _l >> 32;                                        \
 200 } while(0)
 201
 202 #define wrmsr(msr,val1,val2) do {                               \
 203         u64 _l = ((u64)(val2) << 32) | (val1);                  \
 204         paravirt_ops.write_msr((msr), _l);                      \
 205 } while(0)
 206
 207 #define rdmsrl(msr,val) do {                                    \
 208         int _err;                                               \
 209         val = paravirt_ops.read_msr((msr),&_err);               \
 210 } while(0)
 211
 212 #define wrmsrl(msr,val) (paravirt_ops.write_msr((msr),(val)))
 213 #define wrmsr_safe(msr,a,b) ({                                  \
 214         u64 _l = ((u64)(b) << 32) | (a);                        \
 215         paravirt_ops.write_msr((msr),_l);                       \
 216 })
 217
 218 /* rdmsr with exception handling */
 219 #define rdmsr_safe(msr,a,b) ({                                  \
 220         int _err;                                               \
 221         u64 _l = paravirt_ops.read_msr(msr,&_err);              \
 222         (*a) = (u32)_l;                                         \
 223         (*b) = _l >> 32;                                        \
 224         _err; })
 225
 226 #define rdtsc(low,high) do {                                    \
 227         u64 _l = paravirt_ops.read_tsc();                       \
 228         low = (u32)_l;                                          \
 229         high = _l >> 32;                                        \
 230 } while(0)
 231
 232 #define rdtscl(low) do {                                        \
 233         u64 _l = paravirt_ops.read_tsc();                       \
 234         low = (int)_l;                                          \
 235 } while(0)
 236
 237 #define rdtscll(val) (val = paravirt_ops.read_tsc())
 238
 239 #define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
 240
 241 #define rdpmc(counter,low,high) do {                            \
 242         u64 _l = paravirt_ops.read_pmc();                       \
 243         low = (u32)_l;                                          \
 244         high = _l >> 32;                                        \
 245 } while(0)
 246
 247 #define load_TR_desc() (paravirt_ops.load_tr_desc())
 248 #define load_gdt(dtr) (paravirt_ops.load_gdt(dtr))
 249 #define load_idt(dtr) (paravirt_ops.load_idt(dtr))
 250 #define set_ldt(addr, entries) (paravirt_ops.set_ldt((addr), (entries)))
 251 #define store_gdt(dtr) (paravirt_ops.store_gdt(dtr))
 252 #define store_idt(dtr) (paravirt_ops.store_idt(dtr))
 253 #define store_tr(tr) ((tr) = paravirt_ops.store_tr())
 254 #define load_TLS(t,cpu) (paravirt_ops.load_tls((t),(cpu)))
 255 #define write_ldt_entry(dt, entry, low, high)                           \
 256         (paravirt_ops.write_ldt_entry((dt), (entry), (low), (high)))
 257 #define write_gdt_entry(dt, entry, low, high)                           \
 258         (paravirt_ops.write_gdt_entry((dt), (entry), (low), (high)))
 259 #define write_idt_entry(dt, entry, low, high)                           \
 260         (paravirt_ops.write_idt_entry((dt), (entry), (low), (high)))
 261 #define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask))
 262
 263 /* The paravirtualized I/O functions */
 264 static inline void slow_down_io(void) {
 265         paravirt_ops.io_delay();
 266 #ifdef REALLY_SLOW_IO
 267         paravirt_ops.io_delay();
 268         paravirt_ops.io_delay();
 269         paravirt_ops.io_delay();
 270 #endif
 271 }
 272
 273 /* These all sit in the .parainstructions section to tell us what to patch. */
 274 struct paravirt_patch {
 275         u8 *instr;              /* original instructions */
 276         u8 instrtype;           /* type of this instruction */
 277         u8 len;                 /* length of original instruction */
 278         u16 clobbers;           /* what registers you may clobber */
 279 };
 280
 281 #define paravirt_alt(insn_string, typenum, clobber)     \
 282         "771:\n\t" insn_string "\n" "772:\n"            \
 283         ".pushsection .parainstructions,\"a\"\n"        \
 284         "  .long 771b\n"                                \
 285         "  .byte " __stringify(typenum) "\n"            \
 286         "  .byte 772b-771b\n"                           \
 287         "  .short " __stringify(clobber) "\n"           \
 288         ".popsection"
 289
 290 static inline unsigned long __raw_local_save_flags(void)
 291 {
 292         unsigned long f;
 293
 294         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 295                                            "call *%1;"
 296                                            "popl %%edx; popl %%ecx",
 297                                           PARAVIRT_SAVE_FLAGS, CLBR_NONE)
 298                              : "=a"(f): "m"(paravirt_ops.save_fl)
 299                              : "memory", "cc");
 300         return f;
 301 }
 302
 303 static inline void raw_local_irq_restore(unsigned long f)
 304 {
 305         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 306                                            "call *%1;"
 307                                            "popl %%edx; popl %%ecx",
 308                                           PARAVIRT_RESTORE_FLAGS, CLBR_EAX)
 309                              : "=a"(f) : "m" (paravirt_ops.restore_fl), "0"(f)
 310                              : "memory", "cc");
 311 }
 312
 313 static inline void raw_local_irq_disable(void)
 314 {
 315         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 316                                            "call *%0;"
 317                                            "popl %%edx; popl %%ecx",
 318                                           PARAVIRT_IRQ_DISABLE, CLBR_EAX)
 319                              : : "m" (paravirt_ops.irq_disable)
 320                              : "memory", "eax", "cc");
 321 }
 322
 323 static inline void raw_local_irq_enable(void)
 324 {
 325         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 326                                            "call *%0;"
 327                                            "popl %%edx; popl %%ecx",
 328                                           PARAVIRT_IRQ_ENABLE, CLBR_EAX)
 329                              : : "m" (paravirt_ops.irq_enable)
 330                              : "memory", "eax", "cc");
 331 }
 332
 333 static inline unsigned long __raw_local_irq_save(void)
 334 {
 335         unsigned long f;
 336
 337         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 338                                            "call *%1; pushl %%eax;"
 339                                            "call *%2; popl %%eax;"
 340                                            "popl %%edx; popl %%ecx",
 341                                           PARAVIRT_SAVE_FLAGS_IRQ_DISABLE,
 342                                           CLBR_NONE)
 343                              : "=a"(f)
 344                              : "m" (paravirt_ops.save_fl),
 345                                "m" (paravirt_ops.irq_disable)
 346                              : "memory", "cc");
 347         return f;
 348 }
 349
 350 #define CLI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;"             \
 351                      "call *paravirt_ops+%c[irq_disable];"              \
 352                      "popl %%edx; popl %%ecx",                          \
 353                      PARAVIRT_IRQ_DISABLE, CLBR_EAX)
 354
 355 #define STI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;"             \
 356                      "call *paravirt_ops+%c[irq_enable];"               \
 357                      "popl %%edx; popl %%ecx",                          \
 358                      PARAVIRT_IRQ_ENABLE, CLBR_EAX)
 359 #define CLI_STI_CLOBBERS , "%eax"
 360 #define CLI_STI_INPUT_ARGS \
 361         ,                                                               \
 362         [irq_disable] "i" (offsetof(struct paravirt_ops, irq_disable)), \
 363         [irq_enable] "i" (offsetof(struct paravirt_ops, irq_enable))
 364
 365 #else  /* __ASSEMBLY__ */
 366
 367 #define PARA_PATCH(ptype, clobbers, ops)        \
 368 771:;                                           \
 369         ops;                                    \
 370 772:;                                           \
 371         .pushsection .parainstructions,"a";     \
 372          .long 771b;                            \
 373          .byte ptype;                           \
 374          .byte 772b-771b;                       \
 375          .short clobbers;                       \
 376         .popsection
 377
 378 #define INTERRUPT_RETURN                                \
 379         PARA_PATCH(PARAVIRT_INTERRUPT_RETURN, CLBR_ANY, \
 380         jmp *%cs:paravirt_ops+PARAVIRT_iret)
 381
 382 #define DISABLE_INTERRUPTS(clobbers)                    \
 383         PARA_PATCH(PARAVIRT_IRQ_DISABLE, clobbers,      \
 384         pushl %ecx; pushl %edx;                         \
 385         call *paravirt_ops+PARAVIRT_irq_disable;        \
 386         popl %edx; popl %ecx)                           \
 387
 388 #define ENABLE_INTERRUPTS(clobbers)                     \
 389         PARA_PATCH(PARAVIRT_IRQ_ENABLE, clobbers,       \
 390         pushl %ecx; pushl %edx;                         \
 391         call *%cs:paravirt_ops+PARAVIRT_irq_enable;     \
 392         popl %edx; popl %ecx)
 393
 394 #define ENABLE_INTERRUPTS_SYSEXIT                       \
 395         PARA_PATCH(PARAVIRT_STI_SYSEXIT, CLBR_ANY,      \
 396         jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit)
 397
 398 #define GET_CR0_INTO_EAX                        \
 399         call *paravirt_ops+PARAVIRT_read_cr0
 400
 401 #endif /* __ASSEMBLY__ */
 402 #endif /* CONFIG_PARAVIRT */
 403 #endif  /* __ASM_PARAVIRT_H */