linux/arch/x86/include/asm/paravirt.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_X86_PARAVIRT_H
   3#define _ASM_X86_PARAVIRT_H
   4/* Various instructions on x86 need to be replaced for
   5 * para-virtualization: those hooks are defined here. */
   6
   7#ifdef CONFIG_PARAVIRT
   8#include <asm/pgtable_types.h>
   9#include <asm/asm.h>
  10#include <asm/nospec-branch.h>
  11
  12#include <asm/paravirt_types.h>
  13
  14#ifndef __ASSEMBLY__
  15#include <linux/bug.h>
  16#include <linux/types.h>
  17#include <linux/cpumask.h>
  18#include <linux/static_call_types.h>
  19#include <asm/frame.h>
  20
  21u64 dummy_steal_clock(int cpu);
  22u64 dummy_sched_clock(void);
  23
  24DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock);
  25DECLARE_STATIC_CALL(pv_sched_clock, dummy_sched_clock);
  26
  27void paravirt_set_sched_clock(u64 (*func)(void));
  28
  29static inline u64 paravirt_sched_clock(void)
  30{
  31        return static_call(pv_sched_clock)();
  32}
  33
  34struct static_key;
  35extern struct static_key paravirt_steal_enabled;
  36extern struct static_key paravirt_steal_rq_enabled;
  37
  38__visible void __native_queued_spin_unlock(struct qspinlock *lock);
  39bool pv_is_native_spin_unlock(void);
  40__visible bool __native_vcpu_is_preempted(long cpu);
  41bool pv_is_native_vcpu_is_preempted(void);
  42
  43static inline u64 paravirt_steal_clock(int cpu)
  44{
  45        return static_call(pv_steal_clock)(cpu);
  46}
  47
  48#ifdef CONFIG_PARAVIRT_SPINLOCKS
  49void __init paravirt_set_cap(void);
  50#endif
  51
  52/* The paravirtualized I/O functions */
  53static inline void slow_down_io(void)
  54{
  55        PVOP_VCALL0(cpu.io_delay);
  56#ifdef REALLY_SLOW_IO
  57        PVOP_VCALL0(cpu.io_delay);
  58        PVOP_VCALL0(cpu.io_delay);
  59        PVOP_VCALL0(cpu.io_delay);
  60#endif
  61}
  62
  63void native_flush_tlb_local(void);
  64void native_flush_tlb_global(void);
  65void native_flush_tlb_one_user(unsigned long addr);
  66void native_flush_tlb_multi(const struct cpumask *cpumask,
  67                             const struct flush_tlb_info *info);
  68
  69static inline void __flush_tlb_local(void)
  70{
  71        PVOP_VCALL0(mmu.flush_tlb_user);
  72}
  73
  74static inline void __flush_tlb_global(void)
  75{
  76        PVOP_VCALL0(mmu.flush_tlb_kernel);
  77}
  78
  79static inline void __flush_tlb_one_user(unsigned long addr)
  80{
  81        PVOP_VCALL1(mmu.flush_tlb_one_user, addr);
  82}
  83
  84static inline void __flush_tlb_multi(const struct cpumask *cpumask,
  85                                      const struct flush_tlb_info *info)
  86{
  87        PVOP_VCALL2(mmu.flush_tlb_multi, cpumask, info);
  88}
  89
  90static inline void paravirt_tlb_remove_table(struct mmu_gather *tlb, void *table)
  91{
  92        PVOP_VCALL2(mmu.tlb_remove_table, tlb, table);
  93}
  94
  95static inline void paravirt_arch_exit_mmap(struct mm_struct *mm)
  96{
  97        PVOP_VCALL1(mmu.exit_mmap, mm);
  98}
  99
 100static inline void notify_page_enc_status_changed(unsigned long pfn,
 101                                                  int npages, bool enc)
 102{
 103        PVOP_VCALL3(mmu.notify_page_enc_status_changed, pfn, npages, enc);
 104}
 105
 106#ifdef CONFIG_PARAVIRT_XXL
 107static inline void load_sp0(unsigned long sp0)
 108{
 109        PVOP_VCALL1(cpu.load_sp0, sp0);
 110}
 111
 112/* The paravirtualized CPUID instruction. */
 113static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
 114                           unsigned int *ecx, unsigned int *edx)
 115{
 116        PVOP_VCALL4(cpu.cpuid, eax, ebx, ecx, edx);
 117}
 118
 119/*
 120 * These special macros can be used to get or set a debugging register
 121 */
 122static __always_inline unsigned long paravirt_get_debugreg(int reg)
 123{
 124        return PVOP_CALL1(unsigned long, cpu.get_debugreg, reg);
 125}
 126#define get_debugreg(var, reg) var = paravirt_get_debugreg(reg)
 127static __always_inline void set_debugreg(unsigned long val, int reg)
 128{
 129        PVOP_VCALL2(cpu.set_debugreg, reg, val);
 130}
 131
 132static inline unsigned long read_cr0(void)
 133{
 134        return PVOP_CALL0(unsigned long, cpu.read_cr0);
 135}
 136
 137static inline void write_cr0(unsigned long x)
 138{
 139        PVOP_VCALL1(cpu.write_cr0, x);
 140}
 141
 142static __always_inline unsigned long read_cr2(void)
 143{
 144        return PVOP_ALT_CALLEE0(unsigned long, mmu.read_cr2,
 145                                "mov %%cr2, %%rax;",
 146                                ALT_NOT(X86_FEATURE_XENPV));
 147}
 148
 149static __always_inline void write_cr2(unsigned long x)
 150{
 151        PVOP_VCALL1(mmu.write_cr2, x);
 152}
 153
 154static inline unsigned long __read_cr3(void)
 155{
 156        return PVOP_ALT_CALL0(unsigned long, mmu.read_cr3,
 157                              "mov %%cr3, %%rax;", ALT_NOT(X86_FEATURE_XENPV));
 158}
 159
 160static inline void write_cr3(unsigned long x)
 161{
 162        PVOP_ALT_VCALL1(mmu.write_cr3, x,
 163                        "mov %%rdi, %%cr3", ALT_NOT(X86_FEATURE_XENPV));
 164}
 165
 166static inline void __write_cr4(unsigned long x)
 167{
 168        PVOP_VCALL1(cpu.write_cr4, x);
 169}
 170
 171static inline void arch_safe_halt(void)
 172{
 173        PVOP_VCALL0(irq.safe_halt);
 174}
 175
 176static inline void halt(void)
 177{
 178        PVOP_VCALL0(irq.halt);
 179}
 180
 181static inline void wbinvd(void)
 182{
 183        PVOP_ALT_VCALL0(cpu.wbinvd, "wbinvd", ALT_NOT(X86_FEATURE_XENPV));
 184}
 185
 186static inline u64 paravirt_read_msr(unsigned msr)
 187{
 188        return PVOP_CALL1(u64, cpu.read_msr, msr);
 189}
 190
 191static inline void paravirt_write_msr(unsigned msr,
 192                                      unsigned low, unsigned high)
 193{
 194        PVOP_VCALL3(cpu.write_msr, msr, low, high);
 195}
 196
 197static inline u64 paravirt_read_msr_safe(unsigned msr, int *err)
 198{
 199        return PVOP_CALL2(u64, cpu.read_msr_safe, msr, err);
 200}
 201
 202static inline int paravirt_write_msr_safe(unsigned msr,
 203                                          unsigned low, unsigned high)
 204{
 205        return PVOP_CALL3(int, cpu.write_msr_safe, msr, low, high);
 206}
 207
 208#define rdmsr(msr, val1, val2)                  \
 209do {                                            \
 210        u64 _l = paravirt_read_msr(msr);        \
 211        val1 = (u32)_l;                         \
 212        val2 = _l >> 32;                        \
 213} while (0)
 214
 215#define wrmsr(msr, val1, val2)                  \
 216do {                                            \
 217        paravirt_write_msr(msr, val1, val2);    \
 218} while (0)
 219
 220#define rdmsrl(msr, val)                        \
 221do {                                            \
 222        val = paravirt_read_msr(msr);           \
 223} while (0)
 224
 225static inline void wrmsrl(unsigned msr, u64 val)
 226{
 227        wrmsr(msr, (u32)val, (u32)(val>>32));
 228}
 229
 230#define wrmsr_safe(msr, a, b)   paravirt_write_msr_safe(msr, a, b)
 231
 232/* rdmsr with exception handling */
 233#define rdmsr_safe(msr, a, b)                           \
 234({                                                      \
 235        int _err;                                       \
 236        u64 _l = paravirt_read_msr_safe(msr, &_err);    \
 237        (*a) = (u32)_l;                                 \
 238        (*b) = _l >> 32;                                \
 239        _err;                                           \
 240})
 241
 242static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
 243{
 244        int err;
 245
 246        *p = paravirt_read_msr_safe(msr, &err);
 247        return err;
 248}
 249
 250static inline unsigned long long paravirt_read_pmc(int counter)
 251{
 252        return PVOP_CALL1(u64, cpu.read_pmc, counter);
 253}
 254
 255#define rdpmc(counter, low, high)               \
 256do {                                            \
 257        u64 _l = paravirt_read_pmc(counter);    \
 258        low = (u32)_l;                          \
 259        high = _l >> 32;                        \
 260} while (0)
 261
 262#define rdpmcl(counter, val) ((val) = paravirt_read_pmc(counter))
 263
 264static inline void paravirt_alloc_ldt(struct desc_struct *ldt, unsigned entries)
 265{
 266        PVOP_VCALL2(cpu.alloc_ldt, ldt, entries);
 267}
 268
 269static inline void paravirt_free_ldt(struct desc_struct *ldt, unsigned entries)
 270{
 271        PVOP_VCALL2(cpu.free_ldt, ldt, entries);
 272}
 273
 274static inline void load_TR_desc(void)
 275{
 276        PVOP_VCALL0(cpu.load_tr_desc);
 277}
 278static inline void load_gdt(const struct desc_ptr *dtr)
 279{
 280        PVOP_VCALL1(cpu.load_gdt, dtr);
 281}
 282static inline void load_idt(const struct desc_ptr *dtr)
 283{
 284        PVOP_VCALL1(cpu.load_idt, dtr);
 285}
 286static inline void set_ldt(const void *addr, unsigned entries)
 287{
 288        PVOP_VCALL2(cpu.set_ldt, addr, entries);
 289}
 290static inline unsigned long paravirt_store_tr(void)
 291{
 292        return PVOP_CALL0(unsigned long, cpu.store_tr);
 293}
 294
 295#define store_tr(tr)    ((tr) = paravirt_store_tr())
 296static inline void load_TLS(struct thread_struct *t, unsigned cpu)
 297{
 298        PVOP_VCALL2(cpu.load_tls, t, cpu);
 299}
 300
 301static inline void load_gs_index(unsigned int gs)
 302{
 303        PVOP_VCALL1(cpu.load_gs_index, gs);
 304}
 305
 306static inline void write_ldt_entry(struct desc_struct *dt, int entry,
 307                                   const void *desc)
 308{
 309        PVOP_VCALL3(cpu.write_ldt_entry, dt, entry, desc);
 310}
 311
 312static inline void write_gdt_entry(struct desc_struct *dt, int entry,
 313                                   void *desc, int type)
 314{
 315        PVOP_VCALL4(cpu.write_gdt_entry, dt, entry, desc, type);
 316}
 317
 318static inline void write_idt_entry(gate_desc *dt, int entry, const gate_desc *g)
 319{
 320        PVOP_VCALL3(cpu.write_idt_entry, dt, entry, g);
 321}
 322
 323#ifdef CONFIG_X86_IOPL_IOPERM
 324static inline void tss_invalidate_io_bitmap(void)
 325{
 326        PVOP_VCALL0(cpu.invalidate_io_bitmap);
 327}
 328
 329static inline void tss_update_io_bitmap(void)
 330{
 331        PVOP_VCALL0(cpu.update_io_bitmap);
 332}
 333#endif
 334
 335static inline void paravirt_activate_mm(struct mm_struct *prev,
 336                                        struct mm_struct *next)
 337{
 338        PVOP_VCALL2(mmu.activate_mm, prev, next);
 339}
 340
 341static inline void paravirt_arch_dup_mmap(struct mm_struct *oldmm,
 342                                          struct mm_struct *mm)
 343{
 344        PVOP_VCALL2(mmu.dup_mmap, oldmm, mm);
 345}
 346
 347static inline int paravirt_pgd_alloc(struct mm_struct *mm)
 348{
 349        return PVOP_CALL1(int, mmu.pgd_alloc, mm);
 350}
 351
 352static inline void paravirt_pgd_free(struct mm_struct *mm, pgd_t *pgd)
 353{
 354        PVOP_VCALL2(mmu.pgd_free, mm, pgd);
 355}
 356
 357static inline void paravirt_alloc_pte(struct mm_struct *mm, unsigned long pfn)
 358{
 359        PVOP_VCALL2(mmu.alloc_pte, mm, pfn);
 360}
 361static inline void paravirt_release_pte(unsigned long pfn)
 362{
 363        PVOP_VCALL1(mmu.release_pte, pfn);
 364}
 365
 366static inline void paravirt_alloc_pmd(struct mm_struct *mm, unsigned long pfn)
 367{
 368        PVOP_VCALL2(mmu.alloc_pmd, mm, pfn);
 369}
 370
 371static inline void paravirt_release_pmd(unsigned long pfn)
 372{
 373        PVOP_VCALL1(mmu.release_pmd, pfn);
 374}
 375
 376static inline void paravirt_alloc_pud(struct mm_struct *mm, unsigned long pfn)
 377{
 378        PVOP_VCALL2(mmu.alloc_pud, mm, pfn);
 379}
 380static inline void paravirt_release_pud(unsigned long pfn)
 381{
 382        PVOP_VCALL1(mmu.release_pud, pfn);
 383}
 384
 385static inline void paravirt_alloc_p4d(struct mm_struct *mm, unsigned long pfn)
 386{
 387        PVOP_VCALL2(mmu.alloc_p4d, mm, pfn);
 388}
 389
 390static inline void paravirt_release_p4d(unsigned long pfn)
 391{
 392        PVOP_VCALL1(mmu.release_p4d, pfn);
 393}
 394
 395static inline pte_t __pte(pteval_t val)
 396{
 397        return (pte_t) { PVOP_ALT_CALLEE1(pteval_t, mmu.make_pte, val,
 398                                          "mov %%rdi, %%rax",
 399                                          ALT_NOT(X86_FEATURE_XENPV)) };
 400}
 401
 402static inline pteval_t pte_val(pte_t pte)
 403{
 404        return PVOP_ALT_CALLEE1(pteval_t, mmu.pte_val, pte.pte,
 405                                "mov %%rdi, %%rax", ALT_NOT(X86_FEATURE_XENPV));
 406}
 407
 408static inline pgd_t __pgd(pgdval_t val)
 409{
 410        return (pgd_t) { PVOP_ALT_CALLEE1(pgdval_t, mmu.make_pgd, val,
 411                                          "mov %%rdi, %%rax",
 412                                          ALT_NOT(X86_FEATURE_XENPV)) };
 413}
 414
 415static inline pgdval_t pgd_val(pgd_t pgd)
 416{
 417        return PVOP_ALT_CALLEE1(pgdval_t, mmu.pgd_val, pgd.pgd,
 418                                "mov %%rdi, %%rax", ALT_NOT(X86_FEATURE_XENPV));
 419}
 420
 421#define  __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
 422static inline pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr,
 423                                           pte_t *ptep)
 424{
 425        pteval_t ret;
 426
 427        ret = PVOP_CALL3(pteval_t, mmu.ptep_modify_prot_start, vma, addr, ptep);
 428
 429        return (pte_t) { .pte = ret };
 430}
 431
 432static inline void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
 433                                           pte_t *ptep, pte_t old_pte, pte_t pte)
 434{
 435
 436        PVOP_VCALL4(mmu.ptep_modify_prot_commit, vma, addr, ptep, pte.pte);
 437}
 438
 439static inline void set_pte(pte_t *ptep, pte_t pte)
 440{
 441        PVOP_VCALL2(mmu.set_pte, ptep, pte.pte);
 442}
 443
 444static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 445{
 446        PVOP_VCALL2(mmu.set_pmd, pmdp, native_pmd_val(pmd));
 447}
 448
 449static inline pmd_t __pmd(pmdval_t val)
 450{
 451        return (pmd_t) { PVOP_ALT_CALLEE1(pmdval_t, mmu.make_pmd, val,
 452                                          "mov %%rdi, %%rax",
 453                                          ALT_NOT(X86_FEATURE_XENPV)) };
 454}
 455
 456static inline pmdval_t pmd_val(pmd_t pmd)
 457{
 458        return PVOP_ALT_CALLEE1(pmdval_t, mmu.pmd_val, pmd.pmd,
 459                                "mov %%rdi, %%rax", ALT_NOT(X86_FEATURE_XENPV));
 460}
 461
 462static inline void set_pud(pud_t *pudp, pud_t pud)
 463{
 464        PVOP_VCALL2(mmu.set_pud, pudp, native_pud_val(pud));
 465}
 466
 467static inline pud_t __pud(pudval_t val)
 468{
 469        pudval_t ret;
 470
 471        ret = PVOP_ALT_CALLEE1(pudval_t, mmu.make_pud, val,
 472                               "mov %%rdi, %%rax", ALT_NOT(X86_FEATURE_XENPV));
 473
 474        return (pud_t) { ret };
 475}
 476
 477static inline pudval_t pud_val(pud_t pud)
 478{
 479        return PVOP_ALT_CALLEE1(pudval_t, mmu.pud_val, pud.pud,
 480                                "mov %%rdi, %%rax", ALT_NOT(X86_FEATURE_XENPV));
 481}
 482
 483static inline void pud_clear(pud_t *pudp)
 484{
 485        set_pud(pudp, native_make_pud(0));
 486}
 487
 488static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
 489{
 490        p4dval_t val = native_p4d_val(p4d);
 491
 492        PVOP_VCALL2(mmu.set_p4d, p4dp, val);
 493}
 494
 495#if CONFIG_PGTABLE_LEVELS >= 5
 496
 497static inline p4d_t __p4d(p4dval_t val)
 498{
 499        p4dval_t ret = PVOP_ALT_CALLEE1(p4dval_t, mmu.make_p4d, val,
 500                                        "mov %%rdi, %%rax",
 501                                        ALT_NOT(X86_FEATURE_XENPV));
 502
 503        return (p4d_t) { ret };
 504}
 505
 506static inline p4dval_t p4d_val(p4d_t p4d)
 507{
 508        return PVOP_ALT_CALLEE1(p4dval_t, mmu.p4d_val, p4d.p4d,
 509                                "mov %%rdi, %%rax", ALT_NOT(X86_FEATURE_XENPV));
 510}
 511
 512static inline void __set_pgd(pgd_t *pgdp, pgd_t pgd)
 513{
 514        PVOP_VCALL2(mmu.set_pgd, pgdp, native_pgd_val(pgd));
 515}
 516
 517#define set_pgd(pgdp, pgdval) do {                                      \
 518        if (pgtable_l5_enabled())                                               \
 519                __set_pgd(pgdp, pgdval);                                \
 520        else                                                            \
 521                set_p4d((p4d_t *)(pgdp), (p4d_t) { (pgdval).pgd });     \
 522} while (0)
 523
 524#define pgd_clear(pgdp) do {                                            \
 525        if (pgtable_l5_enabled())                                       \
 526                set_pgd(pgdp, native_make_pgd(0));                      \
 527} while (0)
 528
 529#endif  /* CONFIG_PGTABLE_LEVELS == 5 */
 530
 531static inline void p4d_clear(p4d_t *p4dp)
 532{
 533        set_p4d(p4dp, native_make_p4d(0));
 534}
 535
 536static inline void set_pte_atomic(pte_t *ptep, pte_t pte)
 537{
 538        set_pte(ptep, pte);
 539}
 540
 541static inline void pte_clear(struct mm_struct *mm, unsigned long addr,
 542                             pte_t *ptep)
 543{
 544        set_pte(ptep, native_make_pte(0));
 545}
 546
 547static inline void pmd_clear(pmd_t *pmdp)
 548{
 549        set_pmd(pmdp, native_make_pmd(0));
 550}
 551
 552#define  __HAVE_ARCH_START_CONTEXT_SWITCH
 553static inline void arch_start_context_switch(struct task_struct *prev)
 554{
 555        PVOP_VCALL1(cpu.start_context_switch, prev);
 556}
 557
 558static inline void arch_end_context_switch(struct task_struct *next)
 559{
 560        PVOP_VCALL1(cpu.end_context_switch, next);
 561}
 562
 563#define  __HAVE_ARCH_ENTER_LAZY_MMU_MODE
 564static inline void arch_enter_lazy_mmu_mode(void)
 565{
 566        PVOP_VCALL0(mmu.lazy_mode.enter);
 567}
 568
 569static inline void arch_leave_lazy_mmu_mode(void)
 570{
 571        PVOP_VCALL0(mmu.lazy_mode.leave);
 572}
 573
 574static inline void arch_flush_lazy_mmu_mode(void)
 575{
 576        PVOP_VCALL0(mmu.lazy_mode.flush);
 577}
 578
 579static inline void __set_fixmap(unsigned /* enum fixed_addresses */ idx,
 580                                phys_addr_t phys, pgprot_t flags)
 581{
 582        pv_ops.mmu.set_fixmap(idx, phys, flags);
 583}
 584#endif
 585
 586#if defined(CONFIG_SMP) && defined(CONFIG_PARAVIRT_SPINLOCKS)
 587
 588static __always_inline void pv_queued_spin_lock_slowpath(struct qspinlock *lock,
 589                                                        u32 val)
 590{
 591        PVOP_VCALL2(lock.queued_spin_lock_slowpath, lock, val);
 592}
 593
 594static __always_inline void pv_queued_spin_unlock(struct qspinlock *lock)
 595{
 596        PVOP_ALT_VCALLEE1(lock.queued_spin_unlock, lock,
 597                          "movb $0, (%%" _ASM_ARG1 ");",
 598                          ALT_NOT(X86_FEATURE_PVUNLOCK));
 599}
 600
 601static __always_inline void pv_wait(u8 *ptr, u8 val)
 602{
 603        PVOP_VCALL2(lock.wait, ptr, val);
 604}
 605
 606static __always_inline void pv_kick(int cpu)
 607{
 608        PVOP_VCALL1(lock.kick, cpu);
 609}
 610
 611static __always_inline bool pv_vcpu_is_preempted(long cpu)
 612{
 613        return PVOP_ALT_CALLEE1(bool, lock.vcpu_is_preempted, cpu,
 614                                "xor %%" _ASM_AX ", %%" _ASM_AX ";",
 615                                ALT_NOT(X86_FEATURE_VCPUPREEMPT));
 616}
 617
 618void __raw_callee_save___native_queued_spin_unlock(struct qspinlock *lock);
 619bool __raw_callee_save___native_vcpu_is_preempted(long cpu);
 620
 621#endif /* SMP && PARAVIRT_SPINLOCKS */
 622
 623#ifdef CONFIG_X86_32
 624/* save and restore all caller-save registers, except return value */
 625#define PV_SAVE_ALL_CALLER_REGS         "pushl %ecx;"
 626#define PV_RESTORE_ALL_CALLER_REGS      "popl  %ecx;"
 627#else
 628/* save and restore all caller-save registers, except return value */
 629#define PV_SAVE_ALL_CALLER_REGS                                         \
 630        "push %rcx;"                                                    \
 631        "push %rdx;"                                                    \
 632        "push %rsi;"                                                    \
 633        "push %rdi;"                                                    \
 634        "push %r8;"                                                     \
 635        "push %r9;"                                                     \
 636        "push %r10;"                                                    \
 637        "push %r11;"
 638#define PV_RESTORE_ALL_CALLER_REGS                                      \
 639        "pop %r11;"                                                     \
 640        "pop %r10;"                                                     \
 641        "pop %r9;"                                                      \
 642        "pop %r8;"                                                      \
 643        "pop %rdi;"                                                     \
 644        "pop %rsi;"                                                     \
 645        "pop %rdx;"                                                     \
 646        "pop %rcx;"
 647#endif
 648
 649/*
 650 * Generate a thunk around a function which saves all caller-save
 651 * registers except for the return value.  This allows C functions to
 652 * be called from assembler code where fewer than normal registers are
 653 * available.  It may also help code generation around calls from C
 654 * code if the common case doesn't use many registers.
 655 *
 656 * When a callee is wrapped in a thunk, the caller can assume that all
 657 * arg regs and all scratch registers are preserved across the
 658 * call. The return value in rax/eax will not be saved, even for void
 659 * functions.
 660 */
 661#define PV_THUNK_NAME(func) "__raw_callee_save_" #func
 662#define __PV_CALLEE_SAVE_REGS_THUNK(func, section)                      \
 663        extern typeof(func) __raw_callee_save_##func;                   \
 664                                                                        \
 665        asm(".pushsection " section ", \"ax\";"                         \
 666            ".globl " PV_THUNK_NAME(func) ";"                           \
 667            ".type " PV_THUNK_NAME(func) ", @function;"                 \
 668            PV_THUNK_NAME(func) ":"                                     \
 669            ASM_ENDBR                                                   \
 670            FRAME_BEGIN                                                 \
 671            PV_SAVE_ALL_CALLER_REGS                                     \
 672            "call " #func ";"                                           \
 673            PV_RESTORE_ALL_CALLER_REGS                                  \
 674            FRAME_END                                                   \
 675            ASM_RET                                                     \
 676            ".size " PV_THUNK_NAME(func) ", .-" PV_THUNK_NAME(func) ";" \
 677            ".popsection")
 678
 679#define PV_CALLEE_SAVE_REGS_THUNK(func)                 \
 680        __PV_CALLEE_SAVE_REGS_THUNK(func, ".text")
 681
 682/* Get a reference to a callee-save function */
 683#define PV_CALLEE_SAVE(func)                                            \
 684        ((struct paravirt_callee_save) { __raw_callee_save_##func })
 685
 686/* Promise that "func" already uses the right calling convention */
 687#define __PV_IS_CALLEE_SAVE(func)                       \
 688        ((struct paravirt_callee_save) { func })
 689
 690#ifdef CONFIG_PARAVIRT_XXL
 691static __always_inline unsigned long arch_local_save_flags(void)
 692{
 693        return PVOP_ALT_CALLEE0(unsigned long, irq.save_fl, "pushf; pop %%rax;",
 694                                ALT_NOT(X86_FEATURE_XENPV));
 695}
 696
 697static __always_inline void arch_local_irq_disable(void)
 698{
 699        PVOP_ALT_VCALLEE0(irq.irq_disable, "cli;", ALT_NOT(X86_FEATURE_XENPV));
 700}
 701
 702static __always_inline void arch_local_irq_enable(void)
 703{
 704        PVOP_ALT_VCALLEE0(irq.irq_enable, "sti;", ALT_NOT(X86_FEATURE_XENPV));
 705}
 706
 707static __always_inline unsigned long arch_local_irq_save(void)
 708{
 709        unsigned long f;
 710
 711        f = arch_local_save_flags();
 712        arch_local_irq_disable();
 713        return f;
 714}
 715#endif
 716
 717
 718/* Make sure as little as possible of this mess escapes. */
 719#undef PARAVIRT_CALL
 720#undef __PVOP_CALL
 721#undef __PVOP_VCALL
 722#undef PVOP_VCALL0
 723#undef PVOP_CALL0
 724#undef PVOP_VCALL1
 725#undef PVOP_CALL1
 726#undef PVOP_VCALL2
 727#undef PVOP_CALL2
 728#undef PVOP_VCALL3
 729#undef PVOP_CALL3
 730#undef PVOP_VCALL4
 731#undef PVOP_CALL4
 732
 733extern void default_banner(void);
 734
 735#else  /* __ASSEMBLY__ */
 736
 737#define _PVSITE(ptype, ops, word, algn)         \
 738771:;                                           \
 739        ops;                                    \
 740772:;                                           \
 741        .pushsection .parainstructions,"a";     \
 742         .align algn;                           \
 743         word 771b;                             \
 744         .byte ptype;                           \
 745         .byte 772b-771b;                       \
 746        .popsection
 747
 748
 749#ifdef CONFIG_X86_64
 750#ifdef CONFIG_PARAVIRT_XXL
 751
 752#define PARA_PATCH(off)         ((off) / 8)
 753#define PARA_SITE(ptype, ops)   _PVSITE(ptype, ops, .quad, 8)
 754#define PARA_INDIRECT(addr)     *addr(%rip)
 755
 756#ifdef CONFIG_DEBUG_ENTRY
 757.macro PARA_IRQ_save_fl
 758        PARA_SITE(PARA_PATCH(PV_IRQ_save_fl),
 759                  ANNOTATE_RETPOLINE_SAFE;
 760                  call PARA_INDIRECT(pv_ops+PV_IRQ_save_fl);)
 761.endm
 762
 763#define SAVE_FLAGS      ALTERNATIVE "PARA_IRQ_save_fl;", "pushf; pop %rax;", \
 764                                    ALT_NOT(X86_FEATURE_XENPV)
 765#endif
 766#endif /* CONFIG_PARAVIRT_XXL */
 767#endif  /* CONFIG_X86_64 */
 768
 769#endif /* __ASSEMBLY__ */
 770#else  /* CONFIG_PARAVIRT */
 771# define default_banner x86_init_noop
 772#endif /* !CONFIG_PARAVIRT */
 773
 774#ifndef __ASSEMBLY__
 775#ifndef CONFIG_PARAVIRT_XXL
 776static inline void paravirt_arch_dup_mmap(struct mm_struct *oldmm,
 777                                          struct mm_struct *mm)
 778{
 779}
 780#endif
 781
 782#ifndef CONFIG_PARAVIRT
 783static inline void paravirt_arch_exit_mmap(struct mm_struct *mm)
 784{
 785}
 786#endif
 787
 788#ifndef CONFIG_PARAVIRT_SPINLOCKS
 789static inline void paravirt_set_cap(void)
 790{
 791}
 792#endif
 793#endif /* __ASSEMBLY__ */
 794#endif /* _ASM_X86_PARAVIRT_H */
 795