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   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 *alloc_pt)(u32 pfn);
 131         void (fastcall *alloc_pd)(u32 pfn);
 132         void (fastcall *alloc_pd_clone)(u32 pfn, u32 clonepfn, u32 start, u32 count);
 133         void (fastcall *release_pt)(u32 pfn);
 134         void (fastcall *release_pd)(u32 pfn);
 135
 136         void (fastcall *set_pte)(pte_t *ptep, pte_t pteval);
 137         void (fastcall *set_pte_at)(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval);
 138         void (fastcall *set_pmd)(pmd_t *pmdp, pmd_t pmdval);
 139         void (fastcall *pte_update)(struct mm_struct *mm, u32 addr, pte_t *ptep);
 140         void (fastcall *pte_update_defer)(struct mm_struct *mm, u32 addr, pte_t *ptep);
 141 #ifdef CONFIG_X86_PAE
 142         void (fastcall *set_pte_atomic)(pte_t *ptep, pte_t pteval);
 143         void (fastcall *set_pte_present)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
 144         void (fastcall *set_pud)(pud_t *pudp, pud_t pudval);
 145         void (fastcall *pte_clear)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 146         void (fastcall *pmd_clear)(pmd_t *pmdp);
 147 #endif
 148
 149         /* These two are jmp to, not actually called. */
 150         void (fastcall *irq_enable_sysexit)(void);
 151         void (fastcall *iret)(void);
 152 };
 153
 154 /* Mark a paravirt probe function. */
 155 #define paravirt_probe(fn)                                              \
 156  static asmlinkage void (*__paravirtprobe_##fn)(void) __attribute_used__ \
 157                 __attribute__((__section__(".paravirtprobe"))) = fn
 158
 159 extern struct paravirt_ops paravirt_ops;
 160
 161 #define paravirt_enabled() (paravirt_ops.paravirt_enabled)
 162
 163 static inline void load_esp0(struct tss_struct *tss,
 164                              struct thread_struct *thread)
 165 {
 166         paravirt_ops.load_esp0(tss, thread);
 167 }
 168
 169 #define ARCH_SETUP                      paravirt_ops.arch_setup();
 170 static inline unsigned long get_wallclock(void)
 171 {
 172         return paravirt_ops.get_wallclock();
 173 }
 174
 175 static inline int set_wallclock(unsigned long nowtime)
 176 {
 177         return paravirt_ops.set_wallclock(nowtime);
 178 }
 179
 180 static inline void do_time_init(void)
 181 {
 182         return paravirt_ops.time_init();
 183 }
 184
 185 /* The paravirtualized CPUID instruction. */
 186 static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
 187                            unsigned int *ecx, unsigned int *edx)
 188 {
 189         paravirt_ops.cpuid(eax, ebx, ecx, edx);
 190 }
 191
 192 /*
 193  * These special macros can be used to get or set a debugging register
 194  */
 195 #define get_debugreg(var, reg) var = paravirt_ops.get_debugreg(reg)
 196 #define set_debugreg(val, reg) paravirt_ops.set_debugreg(reg, val)
 197
 198 #define clts() paravirt_ops.clts()
 199
 200 #define read_cr0() paravirt_ops.read_cr0()
 201 #define write_cr0(x) paravirt_ops.write_cr0(x)
 202
 203 #define read_cr2() paravirt_ops.read_cr2()
 204 #define write_cr2(x) paravirt_ops.write_cr2(x)
 205
 206 #define read_cr3() paravirt_ops.read_cr3()
 207 #define write_cr3(x) paravirt_ops.write_cr3(x)
 208
 209 #define read_cr4() paravirt_ops.read_cr4()
 210 #define read_cr4_safe(x) paravirt_ops.read_cr4_safe()
 211 #define write_cr4(x) paravirt_ops.write_cr4(x)
 212
 213 static inline void raw_safe_halt(void)
 214 {
 215         paravirt_ops.safe_halt();
 216 }
 217
 218 static inline void halt(void)
 219 {
 220         paravirt_ops.safe_halt();
 221 }
 222 #define wbinvd() paravirt_ops.wbinvd()
 223
 224 #define get_kernel_rpl()  (paravirt_ops.kernel_rpl)
 225
 226 #define rdmsr(msr,val1,val2) do {                               \
 227         int _err;                                               \
 228         u64 _l = paravirt_ops.read_msr(msr,&_err);              \
 229         val1 = (u32)_l;                                         \
 230         val2 = _l >> 32;                                        \
 231 } while(0)
 232
 233 #define wrmsr(msr,val1,val2) do {                               \
 234         u64 _l = ((u64)(val2) << 32) | (val1);                  \
 235         paravirt_ops.write_msr((msr), _l);                      \
 236 } while(0)
 237
 238 #define rdmsrl(msr,val) do {                                    \
 239         int _err;                                               \
 240         val = paravirt_ops.read_msr((msr),&_err);               \
 241 } while(0)
 242
 243 #define wrmsrl(msr,val) (paravirt_ops.write_msr((msr),(val)))
 244 #define wrmsr_safe(msr,a,b) ({                                  \
 245         u64 _l = ((u64)(b) << 32) | (a);                        \
 246         paravirt_ops.write_msr((msr),_l);                       \
 247 })
 248
 249 /* rdmsr with exception handling */
 250 #define rdmsr_safe(msr,a,b) ({                                  \
 251         int _err;                                               \
 252         u64 _l = paravirt_ops.read_msr(msr,&_err);              \
 253         (*a) = (u32)_l;                                         \
 254         (*b) = _l >> 32;                                        \
 255         _err; })
 256
 257 #define rdtsc(low,high) do {                                    \
 258         u64 _l = paravirt_ops.read_tsc();                       \
 259         low = (u32)_l;                                          \
 260         high = _l >> 32;                                        \
 261 } while(0)
 262
 263 #define rdtscl(low) do {                                        \
 264         u64 _l = paravirt_ops.read_tsc();                       \
 265         low = (int)_l;                                          \
 266 } while(0)
 267
 268 #define rdtscll(val) (val = paravirt_ops.read_tsc())
 269
 270 #define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
 271
 272 #define rdpmc(counter,low,high) do {                            \
 273         u64 _l = paravirt_ops.read_pmc();                       \
 274         low = (u32)_l;                                          \
 275         high = _l >> 32;                                        \
 276 } while(0)
 277
 278 #define load_TR_desc() (paravirt_ops.load_tr_desc())
 279 #define load_gdt(dtr) (paravirt_ops.load_gdt(dtr))
 280 #define load_idt(dtr) (paravirt_ops.load_idt(dtr))
 281 #define set_ldt(addr, entries) (paravirt_ops.set_ldt((addr), (entries)))
 282 #define store_gdt(dtr) (paravirt_ops.store_gdt(dtr))
 283 #define store_idt(dtr) (paravirt_ops.store_idt(dtr))
 284 #define store_tr(tr) ((tr) = paravirt_ops.store_tr())
 285 #define load_TLS(t,cpu) (paravirt_ops.load_tls((t),(cpu)))
 286 #define write_ldt_entry(dt, entry, low, high)                           \
 287         (paravirt_ops.write_ldt_entry((dt), (entry), (low), (high)))
 288 #define write_gdt_entry(dt, entry, low, high)                           \
 289         (paravirt_ops.write_gdt_entry((dt), (entry), (low), (high)))
 290 #define write_idt_entry(dt, entry, low, high)                           \
 291         (paravirt_ops.write_idt_entry((dt), (entry), (low), (high)))
 292 #define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask))
 293
 294 /* The paravirtualized I/O functions */
 295 static inline void slow_down_io(void) {
 296         paravirt_ops.io_delay();
 297 #ifdef REALLY_SLOW_IO
 298         paravirt_ops.io_delay();
 299         paravirt_ops.io_delay();
 300         paravirt_ops.io_delay();
 301 #endif
 302 }
 303
 304 #ifdef CONFIG_X86_LOCAL_APIC
 305 /*
 306  * Basic functions accessing APICs.
 307  */
 308 static inline void apic_write(unsigned long reg, unsigned long v)
 309 {
 310         paravirt_ops.apic_write(reg,v);
 311 }
 312
 313 static inline void apic_write_atomic(unsigned long reg, unsigned long v)
 314 {
 315         paravirt_ops.apic_write_atomic(reg,v);
 316 }
 317
 318 static inline unsigned long apic_read(unsigned long reg)
 319 {
 320         return paravirt_ops.apic_read(reg);
 321 }
 322 #endif
 323
 324
 325 #define __flush_tlb() paravirt_ops.flush_tlb_user()
 326 #define __flush_tlb_global() paravirt_ops.flush_tlb_kernel()
 327 #define __flush_tlb_single(addr) paravirt_ops.flush_tlb_single(addr)
 328
 329 #define paravirt_alloc_pt(pfn) paravirt_ops.alloc_pt(pfn)
 330 #define paravirt_release_pt(pfn) paravirt_ops.release_pt(pfn)
 331
 332 #define paravirt_alloc_pd(pfn) paravirt_ops.alloc_pd(pfn)
 333 #define paravirt_alloc_pd_clone(pfn, clonepfn, start, count) \
 334         paravirt_ops.alloc_pd_clone(pfn, clonepfn, start, count)
 335 #define paravirt_release_pd(pfn) paravirt_ops.release_pd(pfn)
 336
 337 static inline void set_pte(pte_t *ptep, pte_t pteval)
 338 {
 339         paravirt_ops.set_pte(ptep, pteval);
 340 }
 341
 342 static inline void set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval)
 343 {
 344         paravirt_ops.set_pte_at(mm, addr, ptep, pteval);
 345 }
 346
 347 static inline void set_pmd(pmd_t *pmdp, pmd_t pmdval)
 348 {
 349         paravirt_ops.set_pmd(pmdp, pmdval);
 350 }
 351
 352 static inline void pte_update(struct mm_struct *mm, u32 addr, pte_t *ptep)
 353 {
 354         paravirt_ops.pte_update(mm, addr, ptep);
 355 }
 356
 357 static inline void pte_update_defer(struct mm_struct *mm, u32 addr, pte_t *ptep)
 358 {
 359         paravirt_ops.pte_update_defer(mm, addr, ptep);
 360 }
 361
 362 #ifdef CONFIG_X86_PAE
 363 static inline void set_pte_atomic(pte_t *ptep, pte_t pteval)
 364 {
 365         paravirt_ops.set_pte_atomic(ptep, pteval);
 366 }
 367
 368 static inline void set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
 369 {
 370         paravirt_ops.set_pte_present(mm, addr, ptep, pte);
 371 }
 372
 373 static inline void set_pud(pud_t *pudp, pud_t pudval)
 374 {
 375         paravirt_ops.set_pud(pudp, pudval);
 376 }
 377
 378 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 379 {
 380         paravirt_ops.pte_clear(mm, addr, ptep);
 381 }
 382
 383 static inline void pmd_clear(pmd_t *pmdp)
 384 {
 385         paravirt_ops.pmd_clear(pmdp);
 386 }
 387 #endif
 388
 389 /* These all sit in the .parainstructions section to tell us what to patch. */
 390 struct paravirt_patch {
 391         u8 *instr;              /* original instructions */
 392         u8 instrtype;           /* type of this instruction */
 393         u8 len;                 /* length of original instruction */
 394         u16 clobbers;           /* what registers you may clobber */
 395 };
 396
 397 #define paravirt_alt(insn_string, typenum, clobber)     \
 398         "771:\n\t" insn_string "\n" "772:\n"            \
 399         ".pushsection .parainstructions,\"a\"\n"        \
 400         "  .long 771b\n"                                \
 401         "  .byte " __stringify(typenum) "\n"            \
 402         "  .byte 772b-771b\n"                           \
 403         "  .short " __stringify(clobber) "\n"           \
 404         ".popsection"
 405
 406 static inline unsigned long __raw_local_save_flags(void)
 407 {
 408         unsigned long f;
 409
 410         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 411                                            "call *%1;"
 412                                            "popl %%edx; popl %%ecx",
 413                                           PARAVIRT_SAVE_FLAGS, CLBR_NONE)
 414                              : "=a"(f): "m"(paravirt_ops.save_fl)
 415                              : "memory", "cc");
 416         return f;
 417 }
 418
 419 static inline void raw_local_irq_restore(unsigned long f)
 420 {
 421         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 422                                            "call *%1;"
 423                                            "popl %%edx; popl %%ecx",
 424                                           PARAVIRT_RESTORE_FLAGS, CLBR_EAX)
 425                              : "=a"(f) : "m" (paravirt_ops.restore_fl), "0"(f)
 426                              : "memory", "cc");
 427 }
 428
 429 static inline void raw_local_irq_disable(void)
 430 {
 431         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 432                                            "call *%0;"
 433                                            "popl %%edx; popl %%ecx",
 434                                           PARAVIRT_IRQ_DISABLE, CLBR_EAX)
 435                              : : "m" (paravirt_ops.irq_disable)
 436                              : "memory", "eax", "cc");
 437 }
 438
 439 static inline void raw_local_irq_enable(void)
 440 {
 441         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 442                                            "call *%0;"
 443                                            "popl %%edx; popl %%ecx",
 444                                           PARAVIRT_IRQ_ENABLE, CLBR_EAX)
 445                              : : "m" (paravirt_ops.irq_enable)
 446                              : "memory", "eax", "cc");
 447 }
 448
 449 static inline unsigned long __raw_local_irq_save(void)
 450 {
 451         unsigned long f;
 452
 453         __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
 454                                            "call *%1; pushl %%eax;"
 455                                            "call *%2; popl %%eax;"
 456                                            "popl %%edx; popl %%ecx",
 457                                           PARAVIRT_SAVE_FLAGS_IRQ_DISABLE,
 458                                           CLBR_NONE)
 459                              : "=a"(f)
 460                              : "m" (paravirt_ops.save_fl),
 461                                "m" (paravirt_ops.irq_disable)
 462                              : "memory", "cc");
 463         return f;
 464 }
 465
 466 #define CLI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;"             \
 467                      "call *paravirt_ops+%c[irq_disable];"              \
 468                      "popl %%edx; popl %%ecx",                          \
 469                      PARAVIRT_IRQ_DISABLE, CLBR_EAX)
 470
 471 #define STI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;"             \
 472                      "call *paravirt_ops+%c[irq_enable];"               \
 473                      "popl %%edx; popl %%ecx",                          \
 474                      PARAVIRT_IRQ_ENABLE, CLBR_EAX)
 475 #define CLI_STI_CLOBBERS , "%eax"
 476 #define CLI_STI_INPUT_ARGS \
 477         ,                                                               \
 478         [irq_disable] "i" (offsetof(struct paravirt_ops, irq_disable)), \
 479         [irq_enable] "i" (offsetof(struct paravirt_ops, irq_enable))
 480
 481 #else  /* __ASSEMBLY__ */
 482
 483 #define PARA_PATCH(ptype, clobbers, ops)        \
 484 771:;                                           \
 485         ops;                                    \
 486 772:;                                           \
 487         .pushsection .parainstructions,"a";     \
 488          .long 771b;                            \
 489          .byte ptype;                           \
 490          .byte 772b-771b;                       \
 491          .short clobbers;                       \
 492         .popsection
 493
 494 #define INTERRUPT_RETURN                                \
 495         PARA_PATCH(PARAVIRT_INTERRUPT_RETURN, CLBR_ANY, \
 496         jmp *%cs:paravirt_ops+PARAVIRT_iret)
 497
 498 #define DISABLE_INTERRUPTS(clobbers)                    \
 499         PARA_PATCH(PARAVIRT_IRQ_DISABLE, clobbers,      \
 500         pushl %ecx; pushl %edx;                         \
 501         call *paravirt_ops+PARAVIRT_irq_disable;        \
 502         popl %edx; popl %ecx)                           \
 503
 504 #define ENABLE_INTERRUPTS(clobbers)                     \
 505         PARA_PATCH(PARAVIRT_IRQ_ENABLE, clobbers,       \
 506         pushl %ecx; pushl %edx;                         \
 507         call *%cs:paravirt_ops+PARAVIRT_irq_enable;     \
 508         popl %edx; popl %ecx)
 509
 510 #define ENABLE_INTERRUPTS_SYSEXIT                       \
 511         PARA_PATCH(PARAVIRT_STI_SYSEXIT, CLBR_ANY,      \
 512         jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit)
 513
 514 #define GET_CR0_INTO_EAX                        \
 515         call *paravirt_ops+PARAVIRT_read_cr0
 516
 517 #endif /* __ASSEMBLY__ */
 518 #endif /* CONFIG_PARAVIRT */
 519 #endif  /* __ASM_PARAVIRT_H */