/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2001 Wind River Systems, Inc.
 * All rights reserved.
 * Written by: John Baldwin <jhb@FreeBSD.org>
 *
 * 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 author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

#ifndef _SYS_PCPU_H_
#define _SYS_PCPU_H_

#ifdef LOCORE
#error "no assembler-serviceable parts inside"
#endif

#include <sys/param.h>
#include <sys/_cpuset.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/_sx.h>
#include <sys/queue.h>
#include <sys/_rmlock.h>
#include <sys/resource.h>
#include <machine/pcpu.h>

#define DPCPU_SETNAME           "set_pcpu"
#define DPCPU_SYMPREFIX         "pcpu_entry_"

#ifdef _KERNEL

/*
 * Define a set for pcpu data.
 */
extern uintptr_t *__start_set_pcpu;
__GLOBL(__start_set_pcpu);
extern uintptr_t *__stop_set_pcpu;
__GLOBL(__stop_set_pcpu);

/*
 * Array of dynamic pcpu base offsets.  Indexed by id.
 */
extern uintptr_t dpcpu_off[];

/*
 * Convenience defines.
 */
#define DPCPU_START             ((uintptr_t)&__start_set_pcpu)
#define DPCPU_STOP              ((uintptr_t)&__stop_set_pcpu)
#define DPCPU_BYTES             (DPCPU_STOP - DPCPU_START)
#define DPCPU_MODMIN            2048
#define DPCPU_SIZE              roundup2(DPCPU_BYTES, PAGE_SIZE)
#define DPCPU_MODSIZE           (DPCPU_SIZE - (DPCPU_BYTES - DPCPU_MODMIN))

/*
 * Declaration and definition.
 */
#define DPCPU_NAME(n)           pcpu_entry_##n
#define DPCPU_DECLARE(t, n)     extern t DPCPU_NAME(n)
/* struct _hack is to stop this from being used with the static keyword. */
#define DPCPU_DEFINE(t, n)      \
    struct _hack; t DPCPU_NAME(n) __section(DPCPU_SETNAME) __used
#if defined(KLD_MODULE) && (defined(__aarch64__) || defined(__riscv) \
                || defined(__powerpc64__) || defined(__i386__))
/*
 * On some architectures the compiler will use PC-relative load to
 * find the address of DPCPU data with the static keyword. We then
 * use this to find the offset of the data in a per-CPU region.
 * This works for in the kernel as we can allocate the space ahead
 * of time, however modules need to allocate a sepatate space and
 * then use relocations to fix the address of the data. As
 * PC-relative data doesn't have a relocation there is nothing for
 * the kernel module linker to fix so data is accessed from the
 * wrong location.
 *
 * This is a workaround until a better solution can be found.
 *
 * VNET_DEFINE_STATIC also has the same workaround.
 */
#define DPCPU_DEFINE_STATIC(t, n)       \
    t DPCPU_NAME(n) __section(DPCPU_SETNAME) __used
#else
#define DPCPU_DEFINE_STATIC(t, n)       \
    static t DPCPU_NAME(n) __section(DPCPU_SETNAME) __used
#endif

/*
 * Accessors with a given base.
 */
#define _DPCPU_PTR(b, n)                                                \
    (__typeof(DPCPU_NAME(n))*)((b) + (uintptr_t)&DPCPU_NAME(n))
#define _DPCPU_GET(b, n)        (*_DPCPU_PTR(b, n))
#define _DPCPU_SET(b, n, v)     (*_DPCPU_PTR(b, n) = v)

/*
 * Accessors for the current cpu.
 */
#define DPCPU_PTR(n)            _DPCPU_PTR(PCPU_GET(dynamic), n)
#define DPCPU_GET(n)            (*DPCPU_PTR(n))
#define DPCPU_SET(n, v)         (*DPCPU_PTR(n) = v)

/*
 * Accessors for remote cpus.
 */
#define DPCPU_ID_PTR(i, n)      _DPCPU_PTR(dpcpu_off[(i)], n)
#define DPCPU_ID_GET(i, n)      (*DPCPU_ID_PTR(i, n))
#define DPCPU_ID_SET(i, n, v)   (*DPCPU_ID_PTR(i, n) = v)

/*
 * Utility macros.
 */
#define DPCPU_SUM(n) __extension__                                      \
({                                                                      \
        u_int _i;                                                       \
        __typeof(*DPCPU_PTR(n)) sum;                                    \
                                                                        \
        sum = 0;                                                        \
        CPU_FOREACH(_i) {                                               \
                sum += *DPCPU_ID_PTR(_i, n);                            \
        }                                                               \
        sum;                                                            \
})

#define DPCPU_VARSUM(n, var) __extension__                              \
({                                                                      \
        u_int _i;                                                       \
        __typeof((DPCPU_PTR(n))->var) sum;                              \
                                                                        \
        sum = 0;                                                        \
        CPU_FOREACH(_i) {                                               \
                sum += (DPCPU_ID_PTR(_i, n))->var;                      \
        }                                                               \
        sum;                                                            \
})

#define DPCPU_ZERO(n) do {                                              \
        u_int _i;                                                       \
                                                                        \
        CPU_FOREACH(_i) {                                               \
                bzero(DPCPU_ID_PTR(_i, n), sizeof(*DPCPU_PTR(n)));      \
        }                                                               \
} while (0)

#endif /* _KERNEL */

/*
 * This structure maps out the global data that needs to be kept on a
 * per-cpu basis.  The members are accessed via the PCPU_GET/SET/PTR
 * macros defined in <machine/pcpu.h>.  Machine dependent fields are
 * defined in the PCPU_MD_FIELDS macro defined in <machine/pcpu.h>.
 */
struct pcpu {
        struct thread   *pc_curthread;          /* Current thread */
        struct thread   *pc_idlethread;         /* Idle thread */
        struct thread   *pc_fpcurthread;        /* Fp state owner */
        struct thread   *pc_deadthread;         /* Zombie thread or NULL */
        struct pcb      *pc_curpcb;             /* Current pcb */
        void            *pc_sched;              /* Scheduler state */
        uint64_t        pc_switchtime;          /* cpu_ticks() at last csw */
        int             pc_switchticks;         /* `ticks' at last csw */
        u_int           pc_cpuid;               /* This cpu number */
        STAILQ_ENTRY(pcpu) pc_allcpu;
        struct lock_list_entry *pc_spinlocks;
        long            pc_cp_time[CPUSTATES];  /* statclock ticks */
        struct _device  *pc_device;             /* CPU device handle */
        void            *pc_netisr;             /* netisr SWI cookie */
        int8_t          pc_vfs_freevnodes;      /* freevnodes counter */
        char            pc_unused1[3];          /* unused pad */
        int             pc_domain;              /* Memory domain. */
        struct rm_queue pc_rm_queue;            /* rmlock list of trackers */
        uintptr_t       pc_dynamic;             /* Dynamic per-cpu data area */
        uint64_t        pc_early_dummy_counter; /* Startup time counter(9) */
        uintptr_t       pc_zpcpu_offset;        /* Offset into zpcpu allocs */

        /*
         * Keep MD fields last, so that CPU-specific variations on a
         * single architecture don't result in offset variations of
         * the machine-independent fields of the pcpu.  Even though
         * the pcpu structure is private to the kernel, some ports
         * (e.g., lsof, part of gtop) define _KERNEL and include this
         * header.  While strictly speaking this is wrong, there's no
         * reason not to keep the offsets of the MI fields constant
         * if only to make kernel debugging easier.
         */
        PCPU_MD_FIELDS;
} __aligned(CACHE_LINE_SIZE);

#ifdef _KERNEL

STAILQ_HEAD(cpuhead, pcpu);

extern struct cpuhead cpuhead;
extern struct pcpu *cpuid_to_pcpu[];

#define curcpu          PCPU_GET(cpuid)
#define curvidata       PCPU_GET(vidata)

#define UMA_PCPU_ALLOC_SIZE             PAGE_SIZE

#include <machine/pcpu_aux.h>

#ifndef curthread
#define curthread       PCPU_GET(curthread)
#endif
#define curproc         (curthread->td_proc)

#ifndef ZPCPU_ASSERT_PROTECTED
#define ZPCPU_ASSERT_PROTECTED() MPASS(curthread->td_critnest > 0)
#endif

#ifndef zpcpu_offset_cpu
#define zpcpu_offset_cpu(cpu)   (UMA_PCPU_ALLOC_SIZE * cpu)
#endif
#ifndef zpcpu_offset
#define zpcpu_offset()          (PCPU_GET(zpcpu_offset))
#endif

#ifndef zpcpu_base_to_offset
#define zpcpu_base_to_offset(base) (base)
#endif
#ifndef zpcpu_offset_to_base
#define zpcpu_offset_to_base(base) (base)
#endif

/* Accessor to elements allocated via UMA_ZONE_PCPU zone. */
#define zpcpu_get(base) ({                                                              \
        __typeof(base) _ptr = (void *)((char *)(base) + zpcpu_offset());                \
        _ptr;                                                                           \
})

#define zpcpu_get_cpu(base, cpu) ({                                                     \
        __typeof(base) _ptr = (void *)((char *)(base) + zpcpu_offset_cpu(cpu));         \
        _ptr;                                                                           \
})

/*
 * This operation is NOT atomic and does not post any barriers.
 * If you use this the assumption is that the target CPU will not
 * be modifying this variable.
 * If you need atomicity use xchg.
 * */
#define zpcpu_replace(base, val) ({                                     \
        __typeof(val) *_ptr = zpcpu_get(base);                          \
        __typeof(val) _old;                                             \
                                                                        \
        _old = *_ptr;                                                   \
        *_ptr = val;                                                    \
        _old;                                                           \
})

#define zpcpu_replace_cpu(base, val, cpu) ({                            \
        __typeof(val) *_ptr = zpcpu_get_cpu(base, cpu);                 \
        __typeof(val) _old;                                             \
                                                                        \
        _old = *_ptr;                                                   \
        *_ptr = val;                                                    \
        _old;                                                           \
})

#ifndef zpcpu_set_protected
#define zpcpu_set_protected(base, val) ({                               \
        ZPCPU_ASSERT_PROTECTED();                                       \
        __typeof(val) *_ptr = zpcpu_get(base);                          \
                                                                        \
        *_ptr = (val);                                                  \
})
#endif

#ifndef zpcpu_add_protected
#define zpcpu_add_protected(base, val) ({                               \
        ZPCPU_ASSERT_PROTECTED();                                       \
        __typeof(val) *_ptr = zpcpu_get(base);                          \
                                                                        \
        *_ptr += (val);                                                 \
})
#endif

#ifndef zpcpu_sub_protected
#define zpcpu_sub_protected(base, val) ({                               \
        ZPCPU_ASSERT_PROTECTED();                                       \
        __typeof(val) *_ptr = zpcpu_get(base);                          \
                                                                        \
        *_ptr -= (val);                                                 \
})
#endif

/*
 * Machine dependent callouts.  cpu_pcpu_init() is responsible for
 * initializing machine dependent fields of struct pcpu, and
 * db_show_mdpcpu() is responsible for handling machine dependent
 * fields for the DDB 'show pcpu' command.
 */
void    cpu_pcpu_init(struct pcpu *pcpu, int cpuid, size_t size);
void    db_show_mdpcpu(struct pcpu *pcpu);

void    *dpcpu_alloc(int size);
void    dpcpu_copy(void *s, int size);
void    dpcpu_free(void *s, int size);
void    dpcpu_init(void *dpcpu, int cpuid);
void    pcpu_destroy(struct pcpu *pcpu);
struct  pcpu *pcpu_find(u_int cpuid);
void    pcpu_init(struct pcpu *pcpu, int cpuid, size_t size);

#endif /* _KERNEL */

#endif /* !_SYS_PCPU_H_ */