/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 2012 Joyent, Inc.  All rights reserved.
 * Copyright (c) 2015 by Delphix. All rights reserved.
 */

#ifndef _UMEM_IMPL_H
#define _UMEM_IMPL_H

#include <umem.h>

#include <sys/sysmacros.h>
#include <sys/time.h>
#include <sys/vmem.h>
#include <thread.h>

#ifdef  __cplusplus
extern "C" {
#endif

/*
 * umem memory allocator: implementation-private data structures
 */

/*
 * Internal flags for umem_cache_create
 */
#define UMC_QCACHE      0x00100000
#define UMC_INTERNAL    0x80000000

/*
 * Cache flags
 */
#define UMF_AUDIT       0x00000001      /* transaction auditing */
#define UMF_DEADBEEF    0x00000002      /* deadbeef checking */
#define UMF_REDZONE     0x00000004      /* redzone checking */
#define UMF_CONTENTS    0x00000008      /* freed-buffer content logging */
#define UMF_CHECKSIGNAL 0x00000010      /* abort when in signal context */
#define UMF_NOMAGAZINE  0x00000020      /* disable per-cpu magazines */
#define UMF_FIREWALL    0x00000040      /* put all bufs before unmapped pages */
#define UMF_LITE        0x00000100      /* lightweight debugging */

#define UMF_HASH        0x00000200      /* cache has hash table */
#define UMF_RANDOMIZE   0x00000400      /* randomize other umem_flags */
#define UMF_PTC         0x00000800      /* cache has per-thread caching */

#define UMF_CHECKNULL   0x00001000      /* heap exhaustion checking */

#define UMF_BUFTAG      (UMF_DEADBEEF | UMF_REDZONE)
#define UMF_TOUCH       (UMF_BUFTAG | UMF_LITE | UMF_CONTENTS)
#define UMF_RANDOM      (UMF_TOUCH | UMF_AUDIT | UMF_NOMAGAZINE)
#define UMF_DEBUG       (UMF_RANDOM | UMF_FIREWALL)

#define UMEM_STACK_DEPTH        umem_stack_depth

#define UMEM_FREE_PATTERN               0xdeadbeefdeadbeefULL
#define UMEM_UNINITIALIZED_PATTERN      0xbaddcafebaddcafeULL
#define UMEM_REDZONE_PATTERN            0xfeedfacefeedfaceULL
#define UMEM_REDZONE_BYTE               0xbb

#define UMEM_FATAL_FLAGS        (UMEM_NOFAIL)
#define UMEM_SLEEP_FLAGS        (0)

/*
 * Redzone size encodings for umem_alloc() / umem_free().  We encode the
 * allocation size, rather than storing it directly, so that umem_free()
 * can distinguish frees of the wrong size from redzone violations.
 */
#define UMEM_SIZE_ENCODE(x)     (251 * (x) + 1)
#define UMEM_SIZE_DECODE(x)     ((x) / 251)
#define UMEM_SIZE_VALID(x)      ((x) % 251 == 1)

/*
 * The bufctl (buffer control) structure keeps some minimal information
 * about each buffer: its address, its slab, and its current linkage,
 * which is either on the slab's freelist (if the buffer is free), or
 * on the cache's buf-to-bufctl hash table (if the buffer is allocated).
 * In the case of non-hashed, or "raw", caches (the common case), only
 * the freelist linkage is necessary: the buffer address is at a fixed
 * offset from the bufctl address, and the slab is at the end of the page.
 *
 * NOTE: bc_next must be the first field; raw buffers have linkage only.
 */
typedef struct umem_bufctl {
        struct umem_bufctl      *bc_next;       /* next bufctl struct */
        void                    *bc_addr;       /* address of buffer */
        struct umem_slab        *bc_slab;       /* controlling slab */
} umem_bufctl_t;

/*
 * The UMF_AUDIT version of the bufctl structure.  The beginning of this
 * structure must be identical to the normal bufctl structure so that
 * pointers are interchangeable.
 */

#define UMEM_BUFCTL_AUDIT_SIZE_DEPTH(frames) \
        ((size_t)(&((umem_bufctl_audit_t *)0)->bc_stack[frames]))

/*
 * umem_bufctl_audits must be allocated from a UMC_NOHASH cache, so we
 * require that 2 of them, plus 2 buftags, plus a umem_slab_t, all fit on
 * a single page.
 *
 * For ILP32, this is about 1000 frames.
 * For LP64, this is about 490 frames.
 */

#define UMEM_BUFCTL_AUDIT_ALIGN 32

#define UMEM_BUFCTL_AUDIT_MAX_SIZE                                      \
        (P2ALIGN((PAGESIZE - sizeof (umem_slab_t))/2 -                  \
            sizeof (umem_buftag_t), UMEM_BUFCTL_AUDIT_ALIGN))

#define UMEM_MAX_STACK_DEPTH                                            \
        ((UMEM_BUFCTL_AUDIT_MAX_SIZE -                                  \
            UMEM_BUFCTL_AUDIT_SIZE_DEPTH(0)) / sizeof (uintptr_t))

typedef struct umem_bufctl_audit {
        struct umem_bufctl      *bc_next;       /* next bufctl struct */
        void                    *bc_addr;       /* address of buffer */
        struct umem_slab        *bc_slab;       /* controlling slab */
        umem_cache_t            *bc_cache;      /* controlling cache */
        hrtime_t                bc_timestamp;   /* transaction time */
        thread_t                bc_thread;      /* thread doing transaction */
        struct umem_bufctl      *bc_lastlog;    /* last log entry */
        void                    *bc_contents;   /* contents at last free */
        int                     bc_depth;       /* stack depth */
        uintptr_t               bc_stack[1];    /* pc stack */
} umem_bufctl_audit_t;

#define UMEM_LOCAL_BUFCTL_AUDIT(bcpp)                                   \
                *(bcpp) = (umem_bufctl_audit_t *)                       \
                    alloca(UMEM_BUFCTL_AUDIT_SIZE)

#define UMEM_BUFCTL_AUDIT_SIZE                                          \
        UMEM_BUFCTL_AUDIT_SIZE_DEPTH(UMEM_STACK_DEPTH)

/*
 * A umem_buftag structure is appended to each buffer whenever any of the
 * UMF_BUFTAG flags (UMF_DEADBEEF, UMF_REDZONE, UMF_VERIFY) are set.
 */
typedef struct umem_buftag {
        uint64_t                bt_redzone;     /* 64-bit redzone pattern */
        umem_bufctl_t           *bt_bufctl;     /* bufctl */
        intptr_t                bt_bxstat;      /* bufctl ^ (alloc/free) */
} umem_buftag_t;

#define UMEM_BUFTAG(cp, buf)            \
        ((umem_buftag_t *)((char *)(buf) + (cp)->cache_buftag))

#define UMEM_BUFCTL(cp, buf)            \
        ((umem_bufctl_t *)((char *)(buf) + (cp)->cache_bufctl))

#define UMEM_BUF(cp, bcp)               \
        ((void *)((char *)(bcp) - (cp)->cache_bufctl))

#define UMEM_SLAB(cp, buf)              \
        ((umem_slab_t *)P2END((uintptr_t)(buf), (cp)->cache_slabsize) - 1)

#define UMEM_CPU_CACHE(cp, cpu)         \
        (umem_cpu_cache_t *)((char *)cp + cpu->cpu_cache_offset)

#define UMEM_MAGAZINE_VALID(cp, mp)     \
        (((umem_slab_t *)P2END((uintptr_t)(mp), PAGESIZE) - 1)->slab_cache == \
            (cp)->cache_magtype->mt_cache)

#define UMEM_SLAB_MEMBER(sp, buf)       \
        ((size_t)(buf) - (size_t)(sp)->slab_base < \
            (sp)->slab_cache->cache_slabsize)

#define UMEM_BUFTAG_ALLOC       0xa110c8edUL
#define UMEM_BUFTAG_FREE        0xf4eef4eeUL

typedef struct umem_slab {
        struct umem_cache       *slab_cache;    /* controlling cache */
        void                    *slab_base;     /* base of allocated memory */
        struct umem_slab        *slab_next;     /* next slab on freelist */
        struct umem_slab        *slab_prev;     /* prev slab on freelist */
        struct umem_bufctl      *slab_head;     /* first free buffer */
        long                    slab_refcnt;    /* outstanding allocations */
        long                    slab_chunks;    /* chunks (bufs) in this slab */
} umem_slab_t;

#define UMEM_HASH_INITIAL       64

#define UMEM_HASH(cp, buf)      \
        ((cp)->cache_hash_table +       \
        (((uintptr_t)(buf) >> (cp)->cache_hash_shift) & (cp)->cache_hash_mask))

typedef struct umem_magazine {
        void    *mag_next;
        void    *mag_round[1];          /* one or more rounds */
} umem_magazine_t;

/*
 * The magazine types for fast per-cpu allocation
 */
typedef struct umem_magtype {
        int             mt_magsize;     /* magazine size (number of rounds) */
        int             mt_align;       /* magazine alignment */
        size_t          mt_minbuf;      /* all smaller buffers qualify */
        size_t          mt_maxbuf;      /* no larger buffers qualify */
        umem_cache_t    *mt_cache;      /* magazine cache */
} umem_magtype_t;

#define UMEM_CPU_CACHE_SIZE     64      /* must be power of 2 */
#define UMEM_CPU_PAD            (UMEM_CPU_CACHE_SIZE - sizeof (mutex_t) - \
        2 * sizeof (uint_t) - 2 * sizeof (void *) - 4 * sizeof (int))
#define UMEM_CACHE_SIZE(ncpus)  \
        ((size_t)(&((umem_cache_t *)0)->cache_cpu[ncpus]))

typedef struct umem_cpu_cache {
        mutex_t         cc_lock;        /* protects this cpu's local cache */
        uint_t          cc_alloc;       /* allocations from this cpu */
        uint_t          cc_free;        /* frees to this cpu */
        umem_magazine_t *cc_loaded;     /* the currently loaded magazine */
        umem_magazine_t *cc_ploaded;    /* the previously loaded magazine */
        int             cc_rounds;      /* number of objects in loaded mag */
        int             cc_prounds;     /* number of objects in previous mag */
        int             cc_magsize;     /* number of rounds in a full mag */
        int             cc_flags;       /* CPU-local copy of cache_flags */
#ifndef _LP64
        char            cc_pad[UMEM_CPU_PAD]; /* for nice alignment (32-bit) */
#endif
} umem_cpu_cache_t;

/*
 * The magazine lists used in the depot.
 */
typedef struct umem_maglist {
        umem_magazine_t *ml_list;       /* magazine list */
        long            ml_total;       /* number of magazines */
        long            ml_min;         /* min since last update */
        long            ml_reaplimit;   /* max reapable magazines */
        uint64_t        ml_alloc;       /* allocations from this list */
} umem_maglist_t;

#define UMEM_CACHE_NAMELEN      31

struct umem_cache {
        /*
         * Statistics
         */
        uint64_t        cache_slab_create;      /* slab creates */
        uint64_t        cache_slab_destroy;     /* slab destroys */
        uint64_t        cache_slab_alloc;       /* slab layer allocations */
        uint64_t        cache_slab_free;        /* slab layer frees */
        uint64_t        cache_alloc_fail;       /* total failed allocations */
        uint64_t        cache_buftotal;         /* total buffers */
        uint64_t        cache_bufmax;           /* max buffers ever */
        uint64_t        cache_rescale;          /* # of hash table rescales */
        uint64_t        cache_lookup_depth;     /* hash lookup depth */
        uint64_t        cache_depot_contention; /* mutex contention count */
        uint64_t        cache_depot_contention_prev; /* previous snapshot */

        /*
         * Cache properties
         */
        char            cache_name[UMEM_CACHE_NAMELEN + 1];
        size_t          cache_bufsize;          /* object size */
        size_t          cache_align;            /* object alignment */
        umem_constructor_t *cache_constructor;
        umem_destructor_t *cache_destructor;
        umem_reclaim_t  *cache_reclaim;
        void            *cache_private;         /* opaque arg to callbacks */
        vmem_t          *cache_arena;           /* vmem source for slabs */
        int             cache_cflags;           /* cache creation flags */
        int             cache_flags;            /* various cache state info */
        int             cache_uflags;           /* UMU_* flags */
        uint32_t        cache_mtbf;             /* induced alloc failure rate */
        umem_cache_t    *cache_next;            /* forward cache linkage */
        umem_cache_t    *cache_prev;            /* backward cache linkage */
        umem_cache_t    *cache_unext;           /* next in update list */
        umem_cache_t    *cache_uprev;           /* prev in update list */
        uint32_t        cache_cpu_mask;         /* mask for cpu offset */

        /*
         * Slab layer
         */
        mutex_t         cache_lock;             /* protects slab layer */
        size_t          cache_chunksize;        /* buf + alignment [+ debug] */
        size_t          cache_slabsize;         /* size of a slab */
        size_t          cache_bufctl;           /* buf-to-bufctl distance */
        size_t          cache_buftag;           /* buf-to-buftag distance */
        size_t          cache_verify;           /* bytes to verify */
        size_t          cache_contents;         /* bytes of saved content */
        size_t          cache_color;            /* next slab color */
        size_t          cache_mincolor;         /* maximum slab color */
        size_t          cache_maxcolor;         /* maximum slab color */
        size_t          cache_hash_shift;       /* get to interesting bits */
        size_t          cache_hash_mask;        /* hash table mask */
        umem_slab_t     *cache_freelist;        /* slab free list */
        umem_slab_t     cache_nullslab;         /* end of freelist marker */
        umem_cache_t    *cache_bufctl_cache;    /* source of bufctls */
        umem_bufctl_t   **cache_hash_table;     /* hash table base */
        /*
         * Depot layer
         */
        mutex_t         cache_depot_lock;       /* protects depot */
        umem_magtype_t  *cache_magtype;         /* magazine type */
        umem_maglist_t  cache_full;             /* full magazines */
        umem_maglist_t  cache_empty;            /* empty magazines */

        /*
         * Per-CPU layer
         */
        umem_cpu_cache_t cache_cpu[1];          /* cache_cpu_mask + 1 entries */
};

typedef struct umem_cpu_log_header {
        mutex_t         clh_lock;
        char            *clh_current;
        size_t          clh_avail;
        int             clh_chunk;
        int             clh_hits;
        char            clh_pad[64 - sizeof (mutex_t) - sizeof (char *) -
                                sizeof (size_t) - 2 * sizeof (int)];
} umem_cpu_log_header_t;

typedef struct umem_log_header {
        mutex_t         lh_lock;
        char            *lh_base;
        int             *lh_free;
        size_t          lh_chunksize;
        int             lh_nchunks;
        int             lh_head;
        int             lh_tail;
        int             lh_hits;
        umem_cpu_log_header_t lh_cpu[1];        /* actually umem_max_ncpus */
} umem_log_header_t;

typedef struct umem_cpu {
        uint32_t cpu_cache_offset;
        uint32_t cpu_number;
} umem_cpu_t;

#define UMEM_MAXBUF     131072

#define UMEM_ALIGN              8       /* min guaranteed alignment */
#define UMEM_ALIGN_SHIFT        3       /* log2(UMEM_ALIGN) */
#define UMEM_VOID_FRACTION      8       /* never waste more than 1/8 of slab */

/*
 * For 64 bits, buffers >= 16 bytes must be 16-byte aligned
 */
#ifdef _LP64
#define UMEM_SECOND_ALIGN 16
#else
#define UMEM_SECOND_ALIGN UMEM_ALIGN
#endif

#define MALLOC_MAGIC                    0x3a10c000 /* 8-byte tag */
#define MEMALIGN_MAGIC                  0x3e3a1000

#ifdef _LP64
#define MALLOC_SECOND_MAGIC             0x16ba7000 /* 8-byte tag, 16-aligned */
#define MALLOC_OVERSIZE_MAGIC           0x06e47000 /* 16-byte tag, _LP64 */
#endif

#define UMEM_MALLOC_ENCODE(type, sz)    (uint32_t)((type) - (sz))
#define UMEM_MALLOC_DECODE(stat, sz)    (uint32_t)((stat) + (sz))
#define UMEM_FREE_PATTERN_32            (uint32_t)(UMEM_FREE_PATTERN)

#define UMU_MAGAZINE_RESIZE     0x00000001
#define UMU_HASH_RESCALE        0x00000002
#define UMU_REAP                0x00000004
#define UMU_NOTIFY              0x08000000
#define UMU_ACTIVE              0x80000000

#define UMEM_READY_INIT_FAILED          -1
#define UMEM_READY_STARTUP              1
#define UMEM_READY_INITING              2
#define UMEM_READY                      3

#ifdef UMEM_STANDALONE
extern void umem_startup(caddr_t, size_t, size_t, caddr_t, caddr_t);
extern int umem_add(caddr_t, size_t);
#endif

/*
 * Private interface with libc for tcumem.
 */
extern uintptr_t _tmem_get_base(void);
extern int _tmem_get_nentries(void);
extern void _tmem_set_cleanup(void(*)(void *, int));

#ifdef  __cplusplus
}
#endif

#endif  /* _UMEM_IMPL_H */