From 5e0b8d508ed51004bd836384293be00950ee62c9 Mon Sep 17 00:00:00 2001 From: Pasha Date: Tue, 20 Feb 2024 18:49:50 +0000 Subject: init gnumach copy --- kern/slab.h | 243 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 243 insertions(+) create mode 100644 kern/slab.h (limited to 'kern/slab.h') diff --git a/kern/slab.h b/kern/slab.h new file mode 100644 index 0000000..4d51755 --- /dev/null +++ b/kern/slab.h @@ -0,0 +1,243 @@ +/* + * Copyright (c) 2011 Free Software Foundation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +/* + * Copyright (c) 2010, 2011 Richard Braun. + * All rights reserved. + * + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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. + * + * + * Object caching memory allocator. + */ + +#ifndef _KERN_SLAB_H +#define _KERN_SLAB_H + +#include +#include +#include +#include +#include +#include +#include +#include + +struct kmem_cache; + +#if SLAB_USE_CPU_POOLS + +/* + * Per-processor cache of pre-constructed objects. + * + * The flags member is a read-only CPU-local copy of the parent cache flags. + */ +struct kmem_cpu_pool { + simple_lock_data_t lock; + int flags; + int size; + int transfer_size; + int nr_objs; + void **array; +} __attribute__((aligned(CPU_L1_SIZE))); + +/* + * When a cache is created, its CPU pool type is determined from the buffer + * size. For small buffer sizes, many objects can be cached in a CPU pool. + * Conversely, for large buffer sizes, this would incur much overhead, so only + * a few objects are stored in a CPU pool. + */ +struct kmem_cpu_pool_type { + size_t buf_size; + int array_size; + size_t array_align; + struct kmem_cache *array_cache; +}; +#endif /* SLAB_USE_CPU_POOLS */ + +/* + * Buffer descriptor. + * + * For normal caches (i.e. without SLAB_CF_VERIFY), bufctls are located at the + * end of (but inside) each buffer. If SLAB_CF_VERIFY is set, bufctls are + * located after each buffer. + * + * When an object is allocated to a client, its bufctl isn't used. This memory + * is instead used for redzoning if cache debugging is in effect. + */ +union kmem_bufctl { + union kmem_bufctl *next; + unsigned long redzone; +}; + +/* + * Buffer tag. + * + * This structure is only used for SLAB_CF_VERIFY caches. It is located after + * the bufctl and includes information about the state of the buffer it + * describes (allocated or not). It should be thought of as a debugging + * extension of the bufctl. + */ +struct kmem_buftag { + unsigned long state; +}; + +/* + * Page-aligned collection of unconstructed buffers. + */ +struct kmem_slab { + struct kmem_cache *cache; + struct list list_node; + struct rbtree_node tree_node; + unsigned long nr_refs; + union kmem_bufctl *first_free; + void *addr; +}; + +/* + * Type for constructor functions. + * + * The pre-constructed state of an object is supposed to include only + * elements such as e.g. linked lists, locks, reference counters. Therefore + * constructors are expected to 1) never fail and 2) not need any + * user-provided data. The first constraint implies that object construction + * never performs dynamic resource allocation, which also means there is no + * need for destructors. + */ +typedef void (*kmem_cache_ctor_t)(void *obj); + +/* + * Cache name buffer size. The size is chosen so that struct + * kmem_cache fits into two cache lines. The size of a cache line on + * a typical CPU is 64 bytes. + */ +#define KMEM_CACHE_NAME_SIZE 24 + +/* + * Cache of objects. + * + * Locking order : cpu_pool -> cache. CPU pools locking is ordered by CPU ID. + * + * Currently, SLAB_USE_CPU_POOLS is not defined. KMEM_CACHE_NAME_SIZE + * is chosen so that the struct fits into two cache lines. The first + * cache line contains all hot fields. + */ +struct kmem_cache { +#if SLAB_USE_CPU_POOLS + /* CPU pool layer */ + struct kmem_cpu_pool cpu_pools[NCPUS]; + struct kmem_cpu_pool_type *cpu_pool_type; +#endif /* SLAB_USE_CPU_POOLS */ + + /* Slab layer */ + simple_lock_data_t lock; + struct list node; /* Cache list linkage */ + struct list partial_slabs; + struct list free_slabs; + struct rbtree active_slabs; + int flags; + size_t bufctl_dist; /* Distance from buffer to bufctl */ + size_t slab_size; + long_natural_t bufs_per_slab; + long_natural_t nr_objs; /* Number of allocated objects */ + long_natural_t nr_free_slabs; + kmem_cache_ctor_t ctor; + /* All fields below are cold */ + size_t obj_size; /* User-provided size */ + /* Assuming ! SLAB_USE_CPU_POOLS, here is the cacheline boundary */ + size_t align; + size_t buf_size; /* Aligned object size */ + size_t color; + size_t color_max; + long_natural_t nr_bufs; /* Total number of buffers */ + long_natural_t nr_slabs; + char name[KMEM_CACHE_NAME_SIZE]; + size_t buftag_dist; /* Distance from buffer to buftag */ + size_t redzone_pad; /* Bytes from end of object to redzone word */ +} __cacheline_aligned; + +/* + * Mach-style declarations for struct kmem_cache. + */ +typedef struct kmem_cache *kmem_cache_t; +#define KMEM_CACHE_NULL ((kmem_cache_t) 0) + +/* + * Cache initialization flags. + */ +#define KMEM_CACHE_NOOFFSLAB 0x1 /* Don't allocate external slab data */ +#define KMEM_CACHE_PHYSMEM 0x2 /* Allocate from physical memory */ +#define KMEM_CACHE_VERIFY 0x4 /* Use debugging facilities */ + +/* + * Initialize a cache. + */ +void kmem_cache_init(struct kmem_cache *cache, const char *name, + size_t obj_size, size_t align, + kmem_cache_ctor_t ctor, int flags); + +/* + * Allocate an object from a cache. + */ +vm_offset_t kmem_cache_alloc(struct kmem_cache *cache); + +/* + * Release an object to its cache. + */ +void kmem_cache_free(struct kmem_cache *cache, vm_offset_t obj); + +/* + * Initialize the memory allocator module. + */ +void slab_bootstrap(void); +void slab_init(void); + +/* + * Release free slabs to the VM system. + */ +void slab_collect(void); + +/* + * Display a summary of all kernel caches. + */ +void slab_info(void); + +#if MACH_KDB +void db_show_slab_info(void); +void db_whatis_slab(vm_offset_t addr); +#endif /* MACH_KDB */ + +#endif /* _KERN_SLAB_H */ -- cgit v1.2.1