/*
 * Copyright (c) 2006-2019 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
#ifndef _SYS_MCACHE_H
#define _SYS_MCACHE_H

#ifdef KERNEL_PRIVATE

#ifdef  __cplusplus
extern "C" {
#endif

#include <sys/types.h>
#include <sys/queue.h>
#include <mach/boolean.h>
#include <kern/locks.h>
#include <libkern/OSAtomic.h>

#ifdef ASSERT
#undef ASSERT
#endif

#ifdef VERIFY
#undef VERIFY
#endif

/*
 * Unlike VERIFY(), ASSERT() is evaluated only in DEBUG/DEVELOPMENT build.
 */
#define VERIFY(EX)      \
	((void)(__probable((EX)) || assfail(#EX, __FILE__, __LINE__)))
#if (DEBUG || DEVELOPMENT)
#define ASSERT(EX)      VERIFY(EX)
#else
#define ASSERT(EX)      ((void)0)
#endif

/*
 * Use CPU_CACHE_LINE_SIZE instead of MAX_CPU_CACHE_LINE_SIZE, unless
 * wasting space is of no concern.
 */
#define MAX_CPU_CACHE_LINE_SIZE 128
#define CPU_CACHE_LINE_SIZE     mcache_cache_line_size()

#ifndef IS_P2ALIGNED
#define IS_P2ALIGNED(v, a) \
	((((uintptr_t)(v)) & ((uintptr_t)(a) - 1)) == 0)
#endif /* IS_P2ALIGNED */

#ifndef P2ROUNDUP
#define P2ROUNDUP(x, align) \
	(-(-((uintptr_t)(x)) & -((uintptr_t)align)))
#endif /* P2ROUNDUP */

#ifndef P2ROUNDDOWN
#define P2ROUNDDOWN(x, align) \
	(((uintptr_t)(x)) & ~((uintptr_t)(align) - 1))
#endif /* P2ROUNDDOWN */

#ifndef P2ALIGN
#define P2ALIGN(x, align) \
	((uintptr_t)(x) & -((uintptr_t)(align)))
#endif /* P2ALIGN */

#define MCACHE_FREE_PATTERN             0xdeadbeefdeadbeefULL
#define MCACHE_UNINITIALIZED_PATTERN    0xbaddcafebaddcafeULL

/*
 * mcache allocation request flags.
 *
 * MCR_NOSLEEP and MCR_FAILOK are mutually exclusive.  The latter is used
 * by the mbuf allocator to handle the implementation of several caches that
 * involve multiple layers of mcache.  It implies a best effort blocking
 * allocation request; if the request cannot be satisfied, the caller will
 * be blocked until further notice, similar to MCR_SLEEP, except that upon
 * a wake up it will return immediately to the caller regardless of whether
 * the request can been fulfilled.
 *
 * MCR_TRYHARD implies a non-blocking allocation request, regardless of
 * whether MCR_NOSLEEP is set.  It informs the allocator that the request
 * should not cause the calling thread to block, and that it must have
 * exhausted all possible schemes to fulfill the request, including doing
 * reclaims and/or purges, before returning to the caller.
 *
 * Regular mcache clients should only use MCR_SLEEP or MCR_NOSLEEP.
 */
#define MCR_SLEEP       0x0000          /* same as M_WAITOK */
#define MCR_NOSLEEP     0x0001          /* same as M_NOWAIT */
#define MCR_FAILOK      0x0100          /* private, for internal use only */
#define MCR_TRYHARD     0x0200          /* private, for internal use only */
#define MCR_USR1        0x1000          /* private, for internal use only */

#define MCR_NONBLOCKING (MCR_NOSLEEP | MCR_FAILOK | MCR_TRYHARD)

/*
 * Generic one-way linked list element structure.  This is used to handle
 * mcache_alloc_ext() requests in order to chain the allocated objects
 * together before returning them to the caller.
 */
typedef struct mcache_obj {
	struct mcache_obj       *obj_next;
} mcache_obj_t;

typedef struct mcache_bkt {
	void            *bkt_next;      /* next bucket in list */
	struct mcache_bkttype *bkt_type; /* bucket type */
	void            *bkt_obj[1];    /* one or more objects */
} mcache_bkt_t;

typedef struct mcache_bktlist {
	mcache_bkt_t    *bl_list;       /* bucket list */
	u_int32_t       bl_total;       /* number of buckets */
	u_int32_t       bl_min;         /* min since last update */
	u_int32_t       bl_reaplimit;   /* max reapable buckets */
	u_int64_t       bl_alloc;       /* allocations from this list */
} mcache_bktlist_t;

typedef struct mcache_bkttype {
	int             bt_bktsize;     /* bucket size (number of elements) */
	size_t          bt_minbuf;      /* all smaller buffers qualify */
	size_t          bt_maxbuf;      /* no larger bfufers qualify */
	struct mcache   *bt_cache;      /* bucket cache */
} mcache_bkttype_t;

typedef struct mcache_cpu {
	decl_lck_mtx_data(, cc_lock);
	mcache_bkt_t    *cc_filled;     /* the currently filled bucket */
	mcache_bkt_t    *cc_pfilled;    /* the previously filled bucket */
	u_int64_t       cc_alloc;       /* allocations from this cpu */
	u_int64_t       cc_free;        /* frees to this cpu */
	int             cc_objs;        /* number of objects in filled bkt */
	int             cc_pobjs;       /* number of objects in previous bkt */
	int             cc_bktsize;     /* number of elements in a full bkt */
} __attribute__((aligned(MAX_CPU_CACHE_LINE_SIZE))) mcache_cpu_t;

typedef unsigned int (*mcache_allocfn_t)(void *, mcache_obj_t ***,
    unsigned int, int);
typedef void (*mcache_freefn_t)(void *, mcache_obj_t *, boolean_t);
typedef void (*mcache_auditfn_t)(void *, mcache_obj_t *, boolean_t);
typedef void (*mcache_logfn_t)(u_int32_t, mcache_obj_t *, boolean_t);
typedef void (*mcache_notifyfn_t)(void *, u_int32_t);

typedef struct mcache {
	/*
	 * Cache properties
	 */
	LIST_ENTRY(mcache) mc_list;     /* cache linkage */
	char            mc_name[32];    /* cache name */
	struct zone     *mc_slab_zone;  /* backend zone allocator */
	mcache_allocfn_t mc_slab_alloc; /* slab layer allocate callback */
	mcache_freefn_t mc_slab_free;   /* slab layer free callback */
	mcache_auditfn_t mc_slab_audit; /* slab layer audit callback */
	mcache_logfn_t mc_slab_log;     /* slab layer log callback */
	mcache_notifyfn_t mc_slab_notify; /* slab layer notify callback */
	void            *mc_private;    /* opaque arg to callbacks */
	size_t          mc_bufsize;     /* object size */
	size_t          mc_align;       /* object alignment */
	u_int32_t       mc_flags;       /* cache creation flags */
	u_int32_t       mc_purge_cnt;   /* # of purges requested by slab */
	u_int32_t       mc_enable_cnt;  /* # of reenables due to purges */
	u_int32_t       mc_waiter_cnt;  /* # of slab layer waiters */
	u_int32_t       mc_wretry_cnt;  /* # of wait retries */
	u_int32_t       mc_nwretry_cnt; /* # of no-wait retry attempts */
	u_int32_t       mc_nwfail_cnt;  /* # of no-wait retries that failed */
	decl_lck_mtx_data(, mc_sync_lock); /* protects purges and reenables */
	lck_grp_t       *mc_sync_lock_grp;
	/*
	 * Keep CPU and buckets layers lock statistics separate.
	 */
	lck_grp_t       *mc_cpu_lock_grp;

	/*
	 * Bucket layer common to all CPUs
	 */
	decl_lck_mtx_data(, mc_bkt_lock);
	lck_grp_t       *mc_bkt_lock_grp;
	mcache_bkttype_t *cache_bkttype;        /* bucket type */
	mcache_bktlist_t mc_full;               /* full buckets */
	mcache_bktlist_t mc_empty;              /* empty buckets */
	size_t          mc_chunksize;           /* bufsize + alignment */
	u_int32_t       mc_bkt_contention;      /* lock contention count */
	u_int32_t       mc_bkt_contention_prev; /* previous snapshot */

	/*
	 * Per-CPU layer, aligned at cache line boundary
	 */
	mcache_cpu_t    mc_cpu[1]
	__attribute__((aligned(MAX_CPU_CACHE_LINE_SIZE)));
} mcache_t;

#define MCACHE_ALIGN    8       /* default guaranteed alignment */

/* Valid values for mc_flags */
#define MCF_VERIFY      0x00000001      /* enable verification */
#define MCF_TRACE       0x00000002      /* enable transaction auditing */
#define MCF_NOCPUCACHE  0x00000010      /* disable CPU layer caching */
#define MCF_NOLEAKLOG   0x00000100      /* disable leak logging */
#define MCF_EXPLEAKLOG  0x00000200      /* expose leak info to user space */

#define MCF_DEBUG       (MCF_VERIFY | MCF_TRACE)
#define MCF_FLAGS_MASK  \
	(MCF_DEBUG | MCF_NOCPUCACHE | MCF_NOLEAKLOG | MCF_EXPLEAKLOG)

/* Valid values for notify callback */
#define MCN_RETRYALLOC  0x00000001      /* Allocation should be retried */

#define MCACHE_STACK_DEPTH 16

#define MCA_TRN_MAX     2               /* Number of transactions to record */

#define DUMP_MCA_BUF_SIZE       512

typedef struct mcache_audit {
	struct mcache_audit *mca_next;  /* next audit struct */
	void            *mca_addr;      /* address of buffer */
	mcache_t        *mca_cache;     /* parent cache of the buffer */
	size_t          mca_contents_size; /* size of saved contents */
	void            *mca_contents;  /* user-specific saved contents */
	void            *mca_uptr;      /* user-specific pointer */
	uint32_t        mca_uflags;     /* user-specific flags */
	uint32_t        mca_next_trn;
	struct mca_trn {
		struct thread   *mca_thread;    /* thread doing transaction */
		uint32_t        mca_tstamp;
		uint16_t        mca_depth;
		void            *mca_stack[MCACHE_STACK_DEPTH];
	} mca_trns[MCA_TRN_MAX];
} mcache_audit_t;

__private_extern__ int assfail(const char *, const char *, int) __abortlike;
__private_extern__ void mcache_init(void);
__private_extern__ unsigned int mcache_getflags(void);
__private_extern__ unsigned int mcache_cache_line_size(void);
__private_extern__ mcache_t *mcache_create(const char *, size_t,
    size_t, u_int32_t, int);
__private_extern__ void *mcache_alloc(mcache_t *, int);
__private_extern__ void mcache_free(mcache_t *, void *);
__private_extern__ mcache_t *mcache_create_ext(const char *, size_t,
    mcache_allocfn_t, mcache_freefn_t, mcache_auditfn_t, mcache_logfn_t,
    mcache_notifyfn_t, void *__unsafe_indexable, u_int32_t, int);
__private_extern__ void mcache_destroy(mcache_t *);
__private_extern__ unsigned int mcache_alloc_ext(mcache_t *, mcache_obj_t **,
    unsigned int, int);
__private_extern__ void mcache_free_ext(mcache_t *, mcache_obj_t *);
__private_extern__ void mcache_reap(void);
__private_extern__ void mcache_reap_now(mcache_t *, boolean_t);
__private_extern__ boolean_t mcache_purge_cache(mcache_t *, boolean_t);
__private_extern__ void mcache_waiter_inc(mcache_t *);
__private_extern__ void mcache_waiter_dec(mcache_t *);
__private_extern__ boolean_t mcache_bkt_isempty(mcache_t *);

struct timeval;
__private_extern__ void mcache_buffer_log(mcache_audit_t *, void *, mcache_t *,
    struct timeval *);
__private_extern__ void mcache_set_pattern(u_int64_t, void *, size_t);
__private_extern__ void *mcache_verify_pattern(u_int64_t, void *, size_t);
__private_extern__ void mcache_audit_free_verify(mcache_audit_t *,
    void *, size_t, size_t);
__private_extern__ void mcache_audit_free_verify_set(mcache_audit_t *,
    void *, size_t, size_t);
__private_extern__ char *mcache_dump_mca(char buf[DUMP_MCA_BUF_SIZE], mcache_audit_t *);

extern mcache_t *mcache_audit_cache;

#ifdef  __cplusplus
}
#endif

#endif /* KERNEL_PRIVATE */

#endif /* _SYS_MCACHE_H */
