FreeBSD/Linux Kernel Cross Reference
sys/sys/systm.h

     /*-
      * SPDX-License-Identifier: BSD-3-Clause
      *
      * Copyright (c) 1982, 1988, 1991, 1993
      *      The Regents of the University of California.  All rights reserved.
      * (c) UNIX System Laboratories, Inc.
      * All or some portions of this file are derived from material licensed
      * to the University of California by American Telephone and Telegraph
      * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     * the permission of UNIX System Laboratories, Inc.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      @(#)systm.h     8.7 (Berkeley) 3/29/95
     * $FreeBSD: releng/12.0/sys/sys/systm.h 339735 2018-10-25 17:00:39Z brooks $
     */
    
    #ifndef _SYS_SYSTM_H_
    #define _SYS_SYSTM_H_
    
    #include <sys/cdefs.h>
    #include <machine/atomic.h>
    #include <machine/cpufunc.h>
    #include <sys/callout.h>
    #include <sys/queue.h>
    #include <sys/stdint.h>         /* for people using printf mainly */
    
    __NULLABILITY_PRAGMA_PUSH
    
    extern int cold;                /* nonzero if we are doing a cold boot */
    extern int suspend_blocked;     /* block suspend due to pending shutdown */
    extern int rebooting;           /* kern_reboot() has been called. */
    extern const char *panicstr;    /* panic message */
    extern char version[];          /* system version */
    extern char compiler_version[]; /* compiler version */
    extern char copyright[];        /* system copyright */
    extern int kstack_pages;        /* number of kernel stack pages */
    
    extern u_long pagesizes[];      /* supported page sizes */
    extern long physmem;            /* physical memory */
    extern long realmem;            /* 'real' memory */
    
    extern char *rootdevnames[2];   /* names of possible root devices */
    
    extern int boothowto;           /* reboot flags, from console subsystem */
    extern int bootverbose;         /* nonzero to print verbose messages */
    
    extern int maxusers;            /* system tune hint */
    extern int ngroups_max;         /* max # of supplemental groups */
    extern int vm_guest;            /* Running as virtual machine guest? */
    
    /*
     * Detected virtual machine guest types. The intention is to expand
     * and/or add to the VM_GUEST_VM type if specific VM functionality is
     * ever implemented (e.g. vendor-specific paravirtualization features).
     * Keep in sync with vm_guest_sysctl_names[].
     */
    enum VM_GUEST { VM_GUEST_NO = 0, VM_GUEST_VM, VM_GUEST_XEN, VM_GUEST_HV,
                    VM_GUEST_VMWARE, VM_GUEST_KVM, VM_GUEST_BHYVE, VM_LAST };
    
    /*
     * These functions need to be declared before the KASSERT macro is invoked in
     * !KASSERT_PANIC_OPTIONAL builds, so their declarations are sort of out of
     * place compared to other function definitions in this header.  On the other
     * hand, this header is a bit disorganized anyway.
     */
    void    panic(const char *, ...) __dead2 __printflike(1, 2);
    void    vpanic(const char *, __va_list) __dead2 __printflike(1, 0);
    
    #if defined(WITNESS) || defined(INVARIANT_SUPPORT)
    #ifdef KASSERT_PANIC_OPTIONAL
    void    kassert_panic(const char *fmt, ...)  __printflike(1, 2);
    #else
    #define kassert_panic   panic
    #endif
    #endif
    
   #ifdef  INVARIANTS              /* The option is always available */
   #define KASSERT(exp,msg) do {                                           \
           if (__predict_false(!(exp)))                                    \
                   kassert_panic msg;                                      \
   } while (0)
   #define VNASSERT(exp, vp, msg) do {                                     \
           if (__predict_false(!(exp))) {                                  \
                   vn_printf(vp, "VNASSERT failed\n");                     \
                   kassert_panic msg;                                      \
           }                                                               \
   } while (0)
   #else
   #define KASSERT(exp,msg) do { \
   } while (0)
   
   #define VNASSERT(exp, vp, msg) do { \
   } while (0)
   #endif
   
   #ifndef CTASSERT        /* Allow lint to override */
   #define CTASSERT(x)     _Static_assert(x, "compile-time assertion failed")
   #endif
   
   #if defined(_KERNEL)
   #include <sys/param.h>          /* MAXCPU */
   #include <sys/pcpu.h>           /* curthread */
   #include <sys/kpilite.h>
   #endif
   
   /*
    * Assert that a pointer can be loaded from memory atomically.
    *
    * This assertion enforces stronger alignment than necessary.  For example,
    * on some architectures, atomicity for unaligned loads will depend on
    * whether or not the load spans multiple cache lines.
    */
   #define ASSERT_ATOMIC_LOAD_PTR(var, msg)                                \
           KASSERT(sizeof(var) == sizeof(void *) &&                        \
               ((uintptr_t)&(var) & (sizeof(void *) - 1)) == 0, msg)
   
   /*
    * Assert that a thread is in critical(9) section.
    */
   #define CRITICAL_ASSERT(td)                                             \
           KASSERT((td)->td_critnest >= 1, ("Not in critical section"));
    
   /*
    * If we have already panic'd and this is the thread that called
    * panic(), then don't block on any mutexes but silently succeed.
    * Otherwise, the kernel will deadlock since the scheduler isn't
    * going to run the thread that holds any lock we need.
    */
   #define SCHEDULER_STOPPED_TD(td)  ({                                    \
           MPASS((td) == curthread);                                       \
           __predict_false((td)->td_stopsched);                            \
   })
   #define SCHEDULER_STOPPED() SCHEDULER_STOPPED_TD(curthread)
   
   /*
    * Align variables.
    */
   #define __read_mostly           __section(".data.read_mostly")
   #define __read_frequently       __section(".data.read_frequently")
   #define __exclusive_cache_line  __aligned(CACHE_LINE_SIZE) \
                                       __section(".data.exclusive_cache_line")
   /*
    * XXX the hints declarations are even more misplaced than most declarations
    * in this file, since they are needed in one file (per arch) and only used
    * in two files.
    * XXX most of these variables should be const.
    */
   extern int osreldate;
   extern bool dynamic_kenv;
   extern struct mtx kenv_lock;
   extern char *kern_envp;
   extern char *md_envp;
   extern char static_env[];
   extern char static_hints[];     /* by config for now */
   
   extern char **kenvp;
   
   extern const void *zero_region; /* address space maps to a zeroed page  */
   
   extern int unmapped_buf_allowed;
   
   #ifdef __LP64__
   #define IOSIZE_MAX              iosize_max()
   #define DEVFS_IOSIZE_MAX        devfs_iosize_max()
   #else
   #define IOSIZE_MAX              SSIZE_MAX
   #define DEVFS_IOSIZE_MAX        SSIZE_MAX
   #endif
   
   /*
    * General function declarations.
    */
   
   struct inpcb;
   struct lock_object;
   struct malloc_type;
   struct mtx;
   struct proc;
   struct socket;
   struct thread;
   struct tty;
   struct ucred;
   struct uio;
   struct _jmp_buf;
   struct trapframe;
   struct eventtimer;
   
   int     setjmp(struct _jmp_buf *) __returns_twice;
   void    longjmp(struct _jmp_buf *, int) __dead2;
   int     dumpstatus(vm_offset_t addr, off_t count);
   int     nullop(void);
   int     eopnotsupp(void);
   int     ureadc(int, struct uio *);
   void    hashdestroy(void *, struct malloc_type *, u_long);
   void    *hashinit(int count, struct malloc_type *type, u_long *hashmask);
   void    *hashinit_flags(int count, struct malloc_type *type,
       u_long *hashmask, int flags);
   #define HASH_NOWAIT     0x00000001
   #define HASH_WAITOK     0x00000002
   
   void    *phashinit(int count, struct malloc_type *type, u_long *nentries);
   void    *phashinit_flags(int count, struct malloc_type *type, u_long *nentries,
       int flags);
   void    g_waitidle(void);
   
   void    cpu_boot(int);
   void    cpu_flush_dcache(void *, size_t);
   void    cpu_rootconf(void);
   void    critical_enter_KBI(void);
   void    critical_exit_KBI(void);
   void    critical_exit_preempt(void);
   void    init_param1(void);
   void    init_param2(long physpages);
   void    init_static_kenv(char *, size_t);
   void    tablefull(const char *);
   
   #if defined(KLD_MODULE) || defined(KTR_CRITICAL) || !defined(_KERNEL) || defined(GENOFFSET)
   #define critical_enter() critical_enter_KBI()
   #define critical_exit() critical_exit_KBI()
   #else
   static __inline void
   critical_enter(void)
   {
           struct thread_lite *td;
   
           td = (struct thread_lite *)curthread;
           td->td_critnest++;
           __compiler_membar();
   }
   
   static __inline void
   critical_exit(void)
   {
           struct thread_lite *td;
   
           td = (struct thread_lite *)curthread;
           KASSERT(td->td_critnest != 0,
               ("critical_exit: td_critnest == 0"));
           __compiler_membar();
           td->td_critnest--;
           __compiler_membar();
           if (__predict_false(td->td_owepreempt))
                   critical_exit_preempt();
   
   }
   #endif
   
   
   #ifdef  EARLY_PRINTF
   typedef void early_putc_t(int ch);
   extern early_putc_t *early_putc;
   #endif
   int     kvprintf(char const *, void (*)(int, void*), void *, int,
               __va_list) __printflike(1, 0);
   void    log(int, const char *, ...) __printflike(2, 3);
   void    log_console(struct uio *);
   void    vlog(int, const char *, __va_list) __printflike(2, 0);
   int     asprintf(char **ret, struct malloc_type *mtp, const char *format, 
               ...) __printflike(3, 4);
   int     printf(const char *, ...) __printflike(1, 2);
   int     snprintf(char *, size_t, const char *, ...) __printflike(3, 4);
   int     sprintf(char *buf, const char *, ...) __printflike(2, 3);
   int     uprintf(const char *, ...) __printflike(1, 2);
   int     vprintf(const char *, __va_list) __printflike(1, 0);
   int     vasprintf(char **ret, struct malloc_type *mtp, const char *format,
               __va_list ap) __printflike(3, 0);
   int     vsnprintf(char *, size_t, const char *, __va_list) __printflike(3, 0);
   int     vsnrprintf(char *, size_t, int, const char *, __va_list) __printflike(4, 0);
   int     vsprintf(char *buf, const char *, __va_list) __printflike(2, 0);
   int     ttyprintf(struct tty *, const char *, ...) __printflike(2, 3);
   int     sscanf(const char *, char const * _Nonnull, ...) __scanflike(2, 3);
   int     vsscanf(const char * _Nonnull, char const * _Nonnull, __va_list)  __scanflike(2, 0);
   long    strtol(const char *, char **, int);
   u_long  strtoul(const char *, char **, int);
   quad_t  strtoq(const char *, char **, int);
   u_quad_t strtouq(const char *, char **, int);
   void    tprintf(struct proc *p, int pri, const char *, ...) __printflike(3, 4);
   void    vtprintf(struct proc *, int, const char *, __va_list) __printflike(3, 0);
   void    hexdump(const void *ptr, int length, const char *hdr, int flags);
   #define HD_COLUMN_MASK  0xff
   #define HD_DELIM_MASK   0xff00
   #define HD_OMIT_COUNT   (1 << 16)
   #define HD_OMIT_HEX     (1 << 17)
   #define HD_OMIT_CHARS   (1 << 18)
   
   #define ovbcopy(f, t, l) bcopy((f), (t), (l))
   void    bcopy(const void * _Nonnull from, void * _Nonnull to, size_t len);
   #define bcopy(from, to, len) __builtin_memmove((to), (from), (len))
   void    bzero(void * _Nonnull buf, size_t len);
   #define bzero(buf, len) __builtin_memset((buf), 0, (len))
   void    explicit_bzero(void * _Nonnull, size_t);
   int     bcmp(const void *b1, const void *b2, size_t len);
   #define bcmp(b1, b2, len) __builtin_memcmp((b1), (b2), (len))
   
   void    *memset(void * _Nonnull buf, int c, size_t len);
   #define memset(buf, c, len) __builtin_memset((buf), (c), (len))
   void    *memcpy(void * _Nonnull to, const void * _Nonnull from, size_t len);
   #define memcpy(to, from, len) __builtin_memcpy((to), (from), (len))
   void    *memmove(void * _Nonnull dest, const void * _Nonnull src, size_t n);
   #define memmove(dest, src, n) __builtin_memmove((dest), (src), (n))
   int     memcmp(const void *b1, const void *b2, size_t len);
   #define memcmp(b1, b2, len) __builtin_memcmp((b1), (b2), (len))
   
   void    *memset_early(void * _Nonnull buf, int c, size_t len);
   #define bzero_early(buf, len) memset_early((buf), 0, (len))
   void    *memcpy_early(void * _Nonnull to, const void * _Nonnull from, size_t len);
   void    *memmove_early(void * _Nonnull dest, const void * _Nonnull src, size_t n);
   #define bcopy_early(from, to, len) memmove_early((to), (from), (len))
   
   int     copystr(const void * _Nonnull __restrict kfaddr,
               void * _Nonnull __restrict kdaddr, size_t len,
               size_t * __restrict lencopied);
   int     copyinstr(const void * __restrict udaddr,
               void * _Nonnull __restrict kaddr, size_t len,
               size_t * __restrict lencopied);
   int     copyin(const void * __restrict udaddr,
               void * _Nonnull __restrict kaddr, size_t len);
   int     copyin_nofault(const void * __restrict udaddr,
               void * _Nonnull __restrict kaddr, size_t len);
   int     copyout(const void * _Nonnull __restrict kaddr,
               void * __restrict udaddr, size_t len);
   int     copyout_nofault(const void * _Nonnull __restrict kaddr,
               void * __restrict udaddr, size_t len);
   
   int     fubyte(volatile const void *base);
   long    fuword(volatile const void *base);
   int     fuword16(volatile const void *base);
   int32_t fuword32(volatile const void *base);
   int64_t fuword64(volatile const void *base);
   int     fueword(volatile const void *base, long *val);
   int     fueword32(volatile const void *base, int32_t *val);
   int     fueword64(volatile const void *base, int64_t *val);
   int     subyte(volatile void *base, int byte);
   int     suword(volatile void *base, long word);
   int     suword16(volatile void *base, int word);
   int     suword32(volatile void *base, int32_t word);
   int     suword64(volatile void *base, int64_t word);
   uint32_t casuword32(volatile uint32_t *base, uint32_t oldval, uint32_t newval);
   u_long  casuword(volatile u_long *p, u_long oldval, u_long newval);
   int     casueword32(volatile uint32_t *base, uint32_t oldval, uint32_t *oldvalp,
               uint32_t newval);
   int     casueword(volatile u_long *p, u_long oldval, u_long *oldvalp,
               u_long newval);
   
   void    realitexpire(void *);
   
   int     sysbeep(int hertz, int period);
   
   void    hardclock(int cnt, int usermode);
   void    hardclock_sync(int cpu);
   void    softclock(void *);
   void    statclock(int cnt, int usermode);
   void    profclock(int cnt, int usermode, uintfptr_t pc);
   
   int     hardclockintr(void);
   
   void    startprofclock(struct proc *);
   void    stopprofclock(struct proc *);
   void    cpu_startprofclock(void);
   void    cpu_stopprofclock(void);
   void    suspendclock(void);
   void    resumeclock(void);
   sbintime_t      cpu_idleclock(void);
   void    cpu_activeclock(void);
   void    cpu_new_callout(int cpu, sbintime_t bt, sbintime_t bt_opt);
   void    cpu_et_frequency(struct eventtimer *et, uint64_t newfreq);
   extern int      cpu_disable_c2_sleep;
   extern int      cpu_disable_c3_sleep;
   
   char    *kern_getenv(const char *name);
   void    freeenv(char *env);
   int     getenv_int(const char *name, int *data);
   int     getenv_uint(const char *name, unsigned int *data);
   int     getenv_long(const char *name, long *data);
   int     getenv_ulong(const char *name, unsigned long *data);
   int     getenv_string(const char *name, char *data, int size);
   int     getenv_int64(const char *name, int64_t *data);
   int     getenv_uint64(const char *name, uint64_t *data);
   int     getenv_quad(const char *name, quad_t *data);
   int     kern_setenv(const char *name, const char *value);
   int     kern_unsetenv(const char *name);
   int     testenv(const char *name);
   
   int     getenv_array(const char *name, void *data, int size, int *psize,
       int type_size, bool allow_signed);
   #define GETENV_UNSIGNED false   /* negative numbers not allowed */
   #define GETENV_SIGNED   true    /* negative numbers allowed */
   
   typedef uint64_t (cpu_tick_f)(void);
   void set_cputicker(cpu_tick_f *func, uint64_t freq, unsigned var);
   extern cpu_tick_f *cpu_ticks;
   uint64_t cpu_tickrate(void);
   uint64_t cputick2usec(uint64_t tick);
   
   #ifdef APM_FIXUP_CALLTODO
   struct timeval;
   void    adjust_timeout_calltodo(struct timeval *time_change);
   #endif /* APM_FIXUP_CALLTODO */
   
   #include <sys/libkern.h>
   
   /* Initialize the world */
   void    consinit(void);
   void    cpu_initclocks(void);
   void    cpu_initclocks_bsp(void);
   void    cpu_initclocks_ap(void);
   void    usrinfoinit(void);
   
   /* Finalize the world */
   void    kern_reboot(int) __dead2;
   void    shutdown_nice(int);
   
   /* Timeouts */
   typedef void timeout_t(void *); /* timeout function type */
   #define CALLOUT_HANDLE_INITIALIZER(handle)      \
           { NULL }
   
   void    callout_handle_init(struct callout_handle *);
   struct  callout_handle timeout(timeout_t *, void *, int);
   void    untimeout(timeout_t *, void *, struct callout_handle);
   
   /* Stubs for obsolete functions that used to be for interrupt management */
   static __inline intrmask_t      splbio(void)            { return 0; }
   static __inline intrmask_t      splcam(void)            { return 0; }
   static __inline intrmask_t      splclock(void)          { return 0; }
   static __inline intrmask_t      splhigh(void)           { return 0; }
   static __inline intrmask_t      splimp(void)            { return 0; }
   static __inline intrmask_t      splnet(void)            { return 0; }
   static __inline intrmask_t      spltty(void)            { return 0; }
   static __inline void            splx(intrmask_t ipl __unused)   { return; }
   
   /*
    * Common `proc' functions are declared here so that proc.h can be included
    * less often.
    */
   int     _sleep(void * _Nonnull chan, struct lock_object *lock, int pri,
              const char *wmesg, sbintime_t sbt, sbintime_t pr, int flags);
   #define msleep(chan, mtx, pri, wmesg, timo)                             \
           _sleep((chan), &(mtx)->lock_object, (pri), (wmesg),             \
               tick_sbt * (timo), 0, C_HARDCLOCK)
   #define msleep_sbt(chan, mtx, pri, wmesg, bt, pr, flags)                \
           _sleep((chan), &(mtx)->lock_object, (pri), (wmesg), (bt), (pr), \
               (flags))
   int     msleep_spin_sbt(void * _Nonnull chan, struct mtx *mtx,
               const char *wmesg, sbintime_t sbt, sbintime_t pr, int flags);
   #define msleep_spin(chan, mtx, wmesg, timo)                             \
           msleep_spin_sbt((chan), (mtx), (wmesg), tick_sbt * (timo),      \
               0, C_HARDCLOCK)
   int     pause_sbt(const char *wmesg, sbintime_t sbt, sbintime_t pr,
               int flags);
   #define pause(wmesg, timo)                                              \
           pause_sbt((wmesg), tick_sbt * (timo), 0, C_HARDCLOCK)
   #define pause_sig(wmesg, timo)                                          \
           pause_sbt((wmesg), tick_sbt * (timo), 0, C_HARDCLOCK | C_CATCH)
   #define tsleep(chan, pri, wmesg, timo)                                  \
           _sleep((chan), NULL, (pri), (wmesg), tick_sbt * (timo),         \
               0, C_HARDCLOCK)
   #define tsleep_sbt(chan, pri, wmesg, bt, pr, flags)                     \
           _sleep((chan), NULL, (pri), (wmesg), (bt), (pr), (flags))
   void    wakeup(void * chan);
   void    wakeup_one(void * chan);
   
   /*
    * Common `struct cdev *' stuff are declared here to avoid #include poisoning
    */
   
   struct cdev;
   dev_t dev2udev(struct cdev *x);
   const char *devtoname(struct cdev *cdev);
   
   #ifdef __LP64__
   size_t  devfs_iosize_max(void);
   size_t  iosize_max(void);
   #endif
   
   int poll_no_poll(int events);
   
   /* XXX: Should be void nanodelay(u_int nsec); */
   void    DELAY(int usec);
   
   /* Root mount holdback API */
   struct root_hold_token;
   
   struct root_hold_token *root_mount_hold(const char *identifier);
   void root_mount_rel(struct root_hold_token *h);
   int root_mounted(void);
   
   
   /*
    * Unit number allocation API. (kern/subr_unit.c)
    */
   struct unrhdr;
   struct unrhdr *new_unrhdr(int low, int high, struct mtx *mutex);
   void init_unrhdr(struct unrhdr *uh, int low, int high, struct mtx *mutex);
   void delete_unrhdr(struct unrhdr *uh);
   void clear_unrhdr(struct unrhdr *uh);
   void clean_unrhdr(struct unrhdr *uh);
   void clean_unrhdrl(struct unrhdr *uh);
   int alloc_unr(struct unrhdr *uh);
   int alloc_unr_specific(struct unrhdr *uh, u_int item);
   int alloc_unrl(struct unrhdr *uh);
   void free_unr(struct unrhdr *uh, u_int item);
   
   void    intr_prof_stack_use(struct thread *td, struct trapframe *frame);
   
   void counted_warning(unsigned *counter, const char *msg);
   
   /*
    * APIs to manage deprecation and obsolescence.
    */
   struct device;
   void _gone_in(int major, const char *msg);
   void _gone_in_dev(struct device *dev, int major, const char *msg);
   #ifdef NO_OBSOLETE_CODE
   #define __gone_ok(m, msg)                                        \
           _Static_assert(m < P_OSREL_MAJOR(__FreeBSD_version)),    \
               "Obsolete code" msg);
   #else
   #define __gone_ok(m, msg)
   #endif
   #define gone_in(major, msg)             __gone_ok(major, msg) _gone_in(major, msg)
   #define gone_in_dev(dev, major, msg)    __gone_ok(major, msg) _gone_in_dev(dev, major, msg)
   #define gone_by_fcp101_dev(dev)                                         \
           gone_in_dev((dev), 13,                                          \
               "see https://github.com/freebsd/fcp/blob/master/fcp-0101.md")
   
   __NULLABILITY_PRAGMA_POP
   
   #endif /* !_SYS_SYSTM_H_ */

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