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 #include <asm/page.h>
   8
   9 #ifdef CONFIG_PARAVIRT
  10 /* These are the most performance critical ops, so we want to be able to patch
  11  * callers */
  12 #define PARAVIRT_IRQ_DISABLE 0
  13 #define PARAVIRT_IRQ_ENABLE 1
  14 #define PARAVIRT_RESTORE_FLAGS 2
  15 #define PARAVIRT_SAVE_FLAGS 3
  16 #define PARAVIRT_SAVE_FLAGS_IRQ_DISABLE 4
  17 #define PARAVIRT_INTERRUPT_RETURN 5
  18 #define PARAVIRT_STI_SYSEXIT 6
  19
  20 /* Bitmask of what can be clobbered: usually at least eax. */
  21 #define CLBR_NONE 0x0
  22 #define CLBR_EAX 0x1
  23 #define CLBR_ECX 0x2
  24 #define CLBR_EDX 0x4
  25 #define CLBR_ANY 0x7
  26
  27 #ifndef __ASSEMBLY__
  28 struct thread_struct;
  29 struct Xgt_desc_struct;
  30 struct tss_struct;
  31 struct mm_struct;
  32 struct paravirt_ops
  33 {
  34         unsigned int kernel_rpl;
  35         int paravirt_enabled;
  36         const char *name;
  37
  38         /*
  39          * Patch may replace one of the defined code sequences with arbitrary
  40          * code, subject to the same register constraints.  This generally
  41          * means the code is not free to clobber any registers other than EAX.
  42          * The patch function should return the number of bytes of code
  43          * generated, as we nop pad the rest in generic code.
  44          */
  45         unsigned (*patch)(u8 type, u16 clobber, void *firstinsn, unsigned len);
  46
  47         void (*arch_setup)(void);
  48         char *(*memory_setup)(void);
  49         void (*init_IRQ)(void);
  50
  51         void (*banner)(void);
  52
  53         unsigned long (*get_wallclock)(void);
  54         int (*set_wallclock)(unsigned long);
  55         void (*time_init)(void);
  56
  57         /* All the function pointers here are declared as "fastcall"
  58            so that we get a specific register-based calling
  59            convention.  This makes it easier to implement inline
  60            assembler replacements. */
  61
  62         void (fastcall *cpuid)(unsigned int *eax, unsigned int *ebx,
  63                       unsigned int *ecx, unsigned int *edx);
  64
  65         unsigned long (fastcall *get_debugreg)(int regno);
  66         void (fastcall *set_debugreg)(int regno, unsigned long value);
  67
  68         void (fastcall *clts)(void);
  69
  70         unsigned long (fastcall *read_cr0)(void);
  71         void (fastcall *write_cr0)(unsigned long);
  72
  73         unsigned long (fastcall *read_cr2)(void);
  74         void (fastcall *write_cr2)(unsigned long);
  75
  76         unsigned long (fastcall *read_cr3)(void);
  77         void (fastcall *write_cr3)(unsigned long);
  78
  79         unsigned long (fastcall *read_cr4_safe)(void);
  80         unsigned long (fastcall *read_cr4)(void);
  81         void (fastcall *write_cr4)(unsigned long);
  82
  83         unsigned long (fastcall *save_fl)(void);
  84         void (fastcall *restore_fl)(unsigned long);
  85         void (fastcall *irq_disable)(void);
  86         void (fastcall *irq_enable)(void);
  87         void (fastcall *safe_halt)(void);
  88         void (fastcall *halt)(void);
  89         void (fastcall *wbinvd)(void);
  90
  91         /* err = 0/-EFAULT.  wrmsr returns 0/-EFAULT. */
  92         u64 (fastcall *read_msr)(unsigned int msr, int *err);
  93         int (fastcall *write_msr)(unsigned int msr, u64 val);
  94
  95         u64 (fastcall *read_tsc)(void);
  96         u64 (fastcall *read_pmc)(void);
  97
  98         void (fastcall *load_tr_desc)(void);
  99         void (fastcall *load_gdt)(const struct Xgt_desc_struct *);
 100         void (fastcall *load_idt)(const struct Xgt_desc_struct *);
 101         void (fastcall *store_gdt)(struct Xgt_desc_struct *);
 102         void (fastcall *store_idt)(struct Xgt_desc_struct *);
 103         void (fastcall *set_ldt)(const void *desc, unsigned entries);
 104         unsigned long (fastcall *store_tr)(void);
 105         void (fastcall *load_tls)(struct thread_struct *t, unsigned int cpu);
 106         void (fastcall *write_ldt_entry)(void *dt, int entrynum,
 107                                          u32 low, u32 high);
 108         void (fastcall *write_gdt_entry)(void *dt, int entrynum,
 109                                          u32 low, u32 high);
 110         void (fastcall *write_idt_entry)(void *dt, int entrynum,
 111                                          u32 low, u32 high);
 112         void (fastcall *load_esp0)(struct tss_struct *tss,
 113                                    struct thread_struct *thread);
 114
 115         void (fastcall *set_iopl_mask)(unsigned mask);
 116
 117         void (fastcall *io_delay)(void);
 118         void (*const_udelay)(unsigned long loops);
 119
 120 #ifdef CONFIG_X86_LOCAL_APIC
 121         void (fastcall *apic_write)(unsigned long reg, unsigned long v);
 122         void (fastcall *apic_write_atomic)(unsigned long reg, unsigned long v);
 123         unsigned long (fastcall *apic_read)(unsigned long reg);
 124 #endif
 125
 126         void (fastcall *flush_tlb_user)(void);
 127         void (fastcall *flush_tlb_kernel)(void);
 128         void (fastcall *flush_tlb_single)(u32 addr);
 129
 130         void (fastcall *set_pte)(pte_t *ptep, pte_t pteval);
 131         void (fastcall *set_pte_at)(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval);
 132         void (fastcall *set_pmd)(pmd_t *pmdp, pmd_t pmdval);
 133         void (fastcall *pte_update)(struct mm_struct *mm, u32 addr, pte_t *ptep);
 134         void (fastcall *pte_update_defer)(struct mm_struct *mm, u32 addr, pte_t *ptep);
 135 #ifdef CONFIG_X86_PAE
 136         void (fastcall *set_pte_atomic)(pte_t *ptep, pte_t pteval);
 137         void (fastcall *set_pte_present)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
 138         void (fastcall *set_pud)(pud_t *pudp, pud_t pudval);
 139         void (fastcall *pte_clear)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 140         void (fastcall *pmd_clear)(pmd_t *pmdp);
 141 #endif
 142
 143         /* These two are jmp to, not actually called. */
 144         void (fastcall *irq_enable_sysexit)(void);
 145         void (fastcall *iret)(void);
 146 };
 147
 148 /* Mark a paravirt probe function. */
 149 #define paravirt_probe(fn)                                              \
 150  static asmlinkage void (*__paravirtprobe_##fn)(void) __attribute_used__ \
 151                 __attribute__((__section__(".paravirtprobe"))) = fn
 152
 153 extern struct paravirt_ops paravirt_ops;
 154
 155 #define paravirt_enabled() (paravirt_ops.paravirt_enabled)
 156
 157 static inline void load_esp0(struct tss_struct *tss,
 158                              struct thread_struct *thread)
 159 {
 160         paravirt_ops.load_esp0(tss, thread);
 161 }
 162
 163 #define ARCH_SETUP                      paravirt_ops.arch_setup();
 164 static inline unsigned long get_wallclock(void)
 165 {
 166         return paravirt_ops.get_wallclock();
 167 }
 168
 169 static inline int set_wallclock(unsigned long nowtime)
 170 {
 171         return paravirt_ops.set_wallclock(nowtime);
 172 }
 173
 174 static inline void do_time_init(void)
 175 {
 176         return paravirt_ops.time_init();
 177 }
 178
 179 /* The paravirtualized CPUID instruction. */
 180 static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
 181                            unsigned int *ecx, unsigned int *edx)
 182 {
 183         paravirt_ops.cpuid(eax, ebx, ecx, edx);
 184 }
 185
 186 /*
 187  * These special macros can be used to get or set a debugging register
 188  */
 189 #define get_debugreg(var, reg) var = paravirt_ops.get_debugreg(reg)
 190 #define set_debugreg(val, reg) paravirt_ops.set_debugreg(reg, val)
 191
 192 #define clts() paravirt_ops.clts()
 193
 194 #define read_cr0() paravirt_ops.read_cr0()
 195 #define write_cr0(x) paravirt_ops.write_cr0(x)
 196
 197 #define read_cr2() paravirt_ops.read_cr2()
 198 #define write_cr2(x) paravirt_ops.write_cr2(x)
 199
 200 #define read_cr3() paravirt_ops.read_cr3()
 201 #define write_cr3(x) paravirt_ops.write_cr3(x)
 202
 203 #define read_cr4() paravirt_ops.read_cr4()
 204 #define read_cr4_safe(x) paravirt_ops.read_cr4_safe()
 205 #define write_cr4(x) paravirt_ops.write_cr4(x)
 206
 207 static inline void raw_safe_halt(void)
 208 {
 209         paravirt_ops.safe_halt();
 210 }
 211
 212 static inline void halt(void)
 213 {
 214         paravirt_ops.safe_halt();
 215 }
 216 #define wbinvd() paravirt_ops.wbinvd()
 217
 218 #define get_kernel_rpl()  (paravirt_ops.kernel_rpl)
 219
 220 #define rdmsr(msr,val1,val2) do {                               \
 221         int _err;                                               \
 222         u64 _l = paravirt_ops.read_msr(msr,&_err);              \
 223         val1 = (u32)_l;                                         \
 224         val2 = _l >> 32;                                        \
 225 } while(0)
 226
 227 #define wrmsr(msr,val1,val2) do {                               \
 228         u64 _l = ((u64)(val2) << 32) | (val1);                  \
 229         paravirt_ops.write_msr((msr), _l);                      \
 230 } while(0)
 231
 232 #define rdmsrl(msr,val) do {                                    \
 233         int _err;                                               \
 234         val = paravirt_ops.read_msr((msr),&_err);               \
 235 } while(0)
 236
 237 #define wrmsrl(msr,val) (paravirt_ops.write_msr((msr),(val)))
 238 #define wrmsr_safe(msr,a,b) ({                                  \
 239         u64 _l = ((u64)(b) << 32) | (a);                        \
 240         paravirt_ops.write_msr((msr),_l);                       \
 241 })
 242
 243 /* rdmsr with exception handling */
 244 #define rdmsr_safe(msr,a,b) ({                                  \
 245         int _err;                                               \
 246         u64 _l = paravirt_ops.read_msr(msr,&_err);              \
 247         (*a) = (u32)_l;                                         \
 248         (*b) = _l >> 32;                                        \
 249         _err; })
 250
 251 #define rdtsc(low,high) do {                                    \
 252         u64 _l = paravirt_ops.read_tsc();                       \
 253         low = (u32)_l;                                          \
 254         high = _l >> 32;                                        \
 255 } while(0)
 256
 257 #define rdtscl(low) do {                                        \
 258         u64 _l = paravirt_ops.read_tsc();                       \
 259         low = (int)_l;                                          \
 260 } while(0)
 261
 262 #define rdtscll(val) (val = paravirt_ops.read_tsc())
 263
 264 #define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
 265
 266 #define rdpmc(counter,low,high) do {                            \
 267         u64 _l = paravirt_ops.read_pmc();                       \
 268         low = (u32)_l;                                          \
 269         high = _l >> 32;                                        \
 270 } while(0)
 271
 272 #define load_TR_desc() (paravirt_ops.load_tr_desc())
 273 #define load_gdt(dtr) (paravirt_ops.load_gdt(dtr))
 274 #define load_idt(dtr) (paravirt_ops.load_idt(dtr))
 275 #define set_ldt(addr, entries) (paravirt_ops.set_ldt((addr), (entries)))
 276 #define store_gdt(dtr) (paravirt_ops.store_gdt(dtr))
 277 #define store_idt(dtr) (paravirt_ops.store_idt(dtr))
 278 #define store_tr(tr) ((tr) = paravirt_ops.store_tr())
 279 #define load_TLS(t,cpu) (paravirt_ops.load_tls((t),(cpu)))
 280 #define write_ldt_entry(dt, entry, low, high)                           \
 281         (paravirt_ops.write_ldt_entry((dt), (entry), (low), (high)))
 282 #define write_gdt_entry(dt, entry, low, high)                           \
 283         (paravirt_ops.write_gdt_entry((dt), (entry), (low), (high)))
 284 #define write_idt_entry(dt, entry, low, high)                           \
 285         (paravirt_ops.write_idt_entry((dt), (entry), (low), (high)))
 286 #define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask))
 287
 288 /* The paravirtualized I/O functions */
 289 static inline void slow_down_io(void) {
 290         paravirt_ops.io_delay();
 291 #ifdef REALLY_SLOW_IO
 292         paravirt_ops.io_delay();
 293         paravirt_ops.io_delay();
 294         paravirt_ops.io_delay();
 295 #endif
 296 }
 297
 298 #ifdef CONFIG_X86_LOCAL_APIC
 299 /*
 300  * Basic functions accessing APICs.
 301  */
 302 static inline void apic_write(unsigned long reg, unsigned long v)
 303 {
 304         paravirt_ops.apic_write(reg,v);
 305 }
 306
 307 static inline void apic_write_atomic(unsigned long reg, unsigned long v)
 308 {
 309         paravirt_ops.apic_write_atomic(reg,v);
 310 }
 311
 312 static inline unsigned long apic_read(unsigned long reg)
 313 {
 314         return paravirt_ops.apic_read(reg);
 315 }
 316 #endif
 317
 318
 319 #define __flush_tlb() paravirt_ops.flush_tlb_user()
 320 #define __flush_tlb_global() paravirt_ops.flush_tlb_kernel()
 321 #define __flush_tlb_single(addr) paravirt_ops.flush_tlb_single(addr)
 322
 323 static inline void set_pte(pte_t *ptep, pte_t pteval)
 324 {
 325         paravirt_ops.set_pte(ptep, pteval);
 326 }
 327
 328 static inline void set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval)
 329 {
 330         paravirt_ops.set_pte_at(mm, addr, ptep, pteval);
 331 }
 332
 333 static inline void set_pmd(pmd_t *pmdp, pmd_t pmdval)
 334 {
 335         paravirt_ops.set_pmd(pmdp, pmdval);
 336 }
 337
 338 static inline void pte_update(struct mm_struct *mm, u32 addr, pte_t *ptep)
 339 {
 340         paravirt_ops.pte_update(mm, addr, ptep);
 341 }
 342
 343 static inline void pte_update_defer(struct mm_struct *mm, u32 addr, pte_t *ptep)
 344 {
 345         paravirt_ops.pte_update_defer(mm, addr, ptep);
 346 }
 347
 348 #ifdef CONFIG_X86_PAE
 349 static inline void set_pte_atomic(pte_t *ptep, pte_t pteval)
 350 {
 351         paravirt_ops.set_pte_atomic(ptep, pteval);
 352 }
 353
 354 static inline void set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
 355 {
 356         paravirt_ops.set_pte_present(mm, addr, ptep, pte);
 357 }
 358
 359 static inline void set_pud(pud_t *pudp, pud_t pudval)
 360 {
 361         paravirt_ops.set_pud(pudp, pudval);
 362 }
 363
 364 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 365 {
 366         paravirt_ops.pte_clear(mm, addr, ptep);
 367 }
 368
 369 static inline void pmd_clear(pmd_t *pmdp)
 370 {
 371         paravirt_ops.pmd_clear(pmdp);
 372 }
 373 #endif
 374
 375 /* These all sit in the .parainstructions section to tell us what to patch. */
 376 struct paravirt_patch {
 377         u8 *instr;              /* original instructions */
 378         u8 instrtype;           /* type of this instruction */
 379         u8 len;                 /* length of original instruction */
 380         u16 clobbers;           /* what registers you may clobber */
 381 };
 382
 383 #define paravirt_alt(insn_string, typenum, clobber)     \
 384         "771:\n\t" insn_string "\n" "772:\n"            \
 385         ".pushsection .parainstructions,\"a\"\n"        \
 386         "  .long 771b\n"                                \
 387         "  .byte " __stringify(typenum) "\n"            \
 388         "  .byte 772b-771b\n"                           \
 389         "  .short " __stringify(clobber) "\n"           \
 390         ".popsection"
 391
 392 static inline unsigned long __raw_local_save_flags(void)
 393 {
 394         unsigned long f;
 395
 396         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 397                                            "call *%1;"
 398                                            "popl %%edx; popl %%ecx",
 399                                           PARAVIRT_SAVE_FLAGS, CLBR_NONE)
 400                              : "=a"(f): "m"(paravirt_ops.save_fl)
 401                              : "memory", "cc");
 402         return f;
 403 }
 404
 405 static inline void raw_local_irq_restore(unsigned long f)
 406 {
 407         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 408                                            "call *%1;"
 409                                            "popl %%edx; popl %%ecx",
 410                                           PARAVIRT_RESTORE_FLAGS, CLBR_EAX)
 411                              : "=a"(f) : "m" (paravirt_ops.restore_fl), "0"(f)
 412                              : "memory", "cc");
 413 }
 414
 415 static inline void raw_local_irq_disable(void)
 416 {
 417         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 418                                            "call *%0;"
 419                                            "popl %%edx; popl %%ecx",
 420                                           PARAVIRT_IRQ_DISABLE, CLBR_EAX)
 421                              : : "m" (paravirt_ops.irq_disable)
 422                              : "memory", "eax", "cc");
 423 }
 424
 425 static inline void raw_local_irq_enable(void)
 426 {
 427         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 428                                            "call *%0;"
 429                                            "popl %%edx; popl %%ecx",
 430                                           PARAVIRT_IRQ_ENABLE, CLBR_EAX)
 431                              : : "m" (paravirt_ops.irq_enable)
 432                              : "memory", "eax", "cc");
 433 }
 434
 435 static inline unsigned long __raw_local_irq_save(void)
 436 {
 437         unsigned long f;
 438
 439         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 440                                            "call *%1; pushl %%eax;"
 441                                            "call *%2; popl %%eax;"
 442                                            "popl %%edx; popl %%ecx",
 443                                           PARAVIRT_SAVE_FLAGS_IRQ_DISABLE,
 444                                           CLBR_NONE)
 445                              : "=a"(f)
 446                              : "m" (paravirt_ops.save_fl),
 447                                "m" (paravirt_ops.irq_disable)
 448                              : "memory", "cc");
 449         return f;
 450 }
 451
 452 #define CLI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;"             \
 453                      "call *paravirt_ops+%c[irq_disable];"              \
 454                      "popl %%edx; popl %%ecx",                          \
 455                      PARAVIRT_IRQ_DISABLE, CLBR_EAX)
 456
 457 #define STI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;"             \
 458                      "call *paravirt_ops+%c[irq_enable];"               \
 459                      "popl %%edx; popl %%ecx",                          \
 460                      PARAVIRT_IRQ_ENABLE, CLBR_EAX)
 461 #define CLI_STI_CLOBBERS , "%eax"
 462 #define CLI_STI_INPUT_ARGS \
 463         ,                                                               \
 464         [irq_disable] "i" (offsetof(struct paravirt_ops, irq_disable)), \
 465         [irq_enable] "i" (offsetof(struct paravirt_ops, irq_enable))
 466
 467 #else  /* __ASSEMBLY__ */
 468
 469 #define PARA_PATCH(ptype, clobbers, ops)        \
 470 771:;                                           \
 471         ops;                                    \
 472 772:;                                           \
 473         .pushsection .parainstructions,"a";     \
 474          .long 771b;                            \
 475          .byte ptype;                           \
 476          .byte 772b-771b;                       \
 477          .short clobbers;                       \
 478         .popsection
 479
 480 #define INTERRUPT_RETURN                                \
 481         PARA_PATCH(PARAVIRT_INTERRUPT_RETURN, CLBR_ANY, \
 482         jmp *%cs:paravirt_ops+PARAVIRT_iret)
 483
 484 #define DISABLE_INTERRUPTS(clobbers)                    \
 485         PARA_PATCH(PARAVIRT_IRQ_DISABLE, clobbers,      \
 486         pushl %ecx; pushl %edx;                         \
 487         call *paravirt_ops+PARAVIRT_irq_disable;        \
 488         popl %edx; popl %ecx)                           \
 489
 490 #define ENABLE_INTERRUPTS(clobbers)                     \
 491         PARA_PATCH(PARAVIRT_IRQ_ENABLE, clobbers,       \
 492         pushl %ecx; pushl %edx;                         \
 493         call *%cs:paravirt_ops+PARAVIRT_irq_enable;     \
 494         popl %edx; popl %ecx)
 495
 496 #define ENABLE_INTERRUPTS_SYSEXIT                       \
 497         PARA_PATCH(PARAVIRT_STI_SYSEXIT, CLBR_ANY,      \
 498         jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit)
 499
 500 #define GET_CR0_INTO_EAX                        \
 501         call *paravirt_ops+PARAVIRT_read_cr0
 502
 503 #endif /* __ASSEMBLY__ */
 504 #endif /* CONFIG_PARAVIRT */
 505 #endif  /* __ASM_PARAVIRT_H */