1 /*- 2 * Copyright (c) 2017 Mellanox Technologies, Ltd. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 #include <linux/compat.h> 29 #include <linux/slab.h> 30 #include <linux/rcupdate.h> 31 #include <linux/kernel.h> 32 #include <linux/irq_work.h> 33 #include <linux/llist.h> 34 35 #include <sys/param.h> 36 #include <sys/taskqueue.h> 37 #include <vm/uma.h> 38 39 struct linux_kmem_rcu { 40 struct rcu_head rcu_head; 41 struct linux_kmem_cache *cache; 42 }; 43 44 struct linux_kmem_cache { 45 uma_zone_t cache_zone; 46 linux_kmem_ctor_t *cache_ctor; 47 unsigned cache_flags; 48 unsigned cache_size; 49 struct llist_head cache_items; 50 struct task cache_task; 51 }; 52 53 #define LINUX_KMEM_TO_RCU(c, m) \ 54 ((struct linux_kmem_rcu *)((char *)(m) + \ 55 (c)->cache_size - sizeof(struct linux_kmem_rcu))) 56 57 #define LINUX_RCU_TO_KMEM(r) \ 58 ((void *)((char *)(r) + sizeof(struct linux_kmem_rcu) - \ 59 (r)->cache->cache_size)) 60 61 static LLIST_HEAD(linux_kfree_async_list); 62 63 static void lkpi_kmem_cache_free_async_fn(void *, int); 64 65 void * 66 lkpi_kmem_cache_alloc(struct linux_kmem_cache *c, gfp_t flags) 67 { 68 return (uma_zalloc_arg(c->cache_zone, c, 69 linux_check_m_flags(flags))); 70 } 71 72 void * 73 lkpi_kmem_cache_zalloc(struct linux_kmem_cache *c, gfp_t flags) 74 { 75 return (uma_zalloc_arg(c->cache_zone, c, 76 linux_check_m_flags(flags | M_ZERO))); 77 } 78 79 static int 80 linux_kmem_ctor(void *mem, int size, void *arg, int flags) 81 { 82 struct linux_kmem_cache *c = arg; 83 84 if (unlikely(c->cache_flags & SLAB_TYPESAFE_BY_RCU)) { 85 struct linux_kmem_rcu *rcu = LINUX_KMEM_TO_RCU(c, mem); 86 87 /* duplicate cache pointer */ 88 rcu->cache = c; 89 } 90 91 /* check for constructor */ 92 if (likely(c->cache_ctor != NULL)) 93 c->cache_ctor(mem); 94 95 return (0); 96 } 97 98 static void 99 linux_kmem_cache_free_rcu_callback(struct rcu_head *head) 100 { 101 struct linux_kmem_rcu *rcu = 102 container_of(head, struct linux_kmem_rcu, rcu_head); 103 104 uma_zfree(rcu->cache->cache_zone, LINUX_RCU_TO_KMEM(rcu)); 105 } 106 107 struct linux_kmem_cache * 108 linux_kmem_cache_create(const char *name, size_t size, size_t align, 109 unsigned flags, linux_kmem_ctor_t *ctor) 110 { 111 struct linux_kmem_cache *c; 112 113 c = malloc(sizeof(*c), M_KMALLOC, M_WAITOK); 114 115 if (flags & SLAB_HWCACHE_ALIGN) 116 align = UMA_ALIGN_CACHE; 117 else if (align != 0) 118 align--; 119 120 if (flags & SLAB_TYPESAFE_BY_RCU) { 121 /* make room for RCU structure */ 122 size = ALIGN(size, sizeof(void *)); 123 size += sizeof(struct linux_kmem_rcu); 124 125 /* create cache_zone */ 126 c->cache_zone = uma_zcreate(name, size, 127 linux_kmem_ctor, NULL, NULL, NULL, 128 align, UMA_ZONE_ZINIT); 129 } else { 130 /* make room for async task list items */ 131 size = MAX(size, sizeof(struct llist_node)); 132 133 /* create cache_zone */ 134 c->cache_zone = uma_zcreate(name, size, 135 ctor ? linux_kmem_ctor : NULL, NULL, 136 NULL, NULL, align, 0); 137 } 138 139 c->cache_flags = flags; 140 c->cache_ctor = ctor; 141 c->cache_size = size; 142 init_llist_head(&c->cache_items); 143 TASK_INIT(&c->cache_task, 0, lkpi_kmem_cache_free_async_fn, c); 144 return (c); 145 } 146 147 static inline void 148 lkpi_kmem_cache_free_rcu(struct linux_kmem_cache *c, void *m) 149 { 150 struct linux_kmem_rcu *rcu = LINUX_KMEM_TO_RCU(c, m); 151 152 call_rcu(&rcu->rcu_head, linux_kmem_cache_free_rcu_callback); 153 } 154 155 static inline void 156 lkpi_kmem_cache_free_sync(struct linux_kmem_cache *c, void *m) 157 { 158 uma_zfree(c->cache_zone, m); 159 } 160 161 static void 162 lkpi_kmem_cache_free_async_fn(void *context, int pending) 163 { 164 struct linux_kmem_cache *c = context; 165 struct llist_node *freed, *next; 166 167 llist_for_each_safe(freed, next, llist_del_all(&c->cache_items)) 168 lkpi_kmem_cache_free_sync(c, freed); 169 } 170 171 static inline void 172 lkpi_kmem_cache_free_async(struct linux_kmem_cache *c, void *m) 173 { 174 if (m == NULL) 175 return; 176 177 llist_add(m, &c->cache_items); 178 taskqueue_enqueue(linux_irq_work_tq, &c->cache_task); 179 } 180 181 void 182 lkpi_kmem_cache_free(struct linux_kmem_cache *c, void *m) 183 { 184 if (unlikely(c->cache_flags & SLAB_TYPESAFE_BY_RCU)) 185 lkpi_kmem_cache_free_rcu(c, m); 186 else if (unlikely(curthread->td_critnest != 0)) 187 lkpi_kmem_cache_free_async(c, m); 188 else 189 lkpi_kmem_cache_free_sync(c, m); 190 } 191 192 void 193 linux_kmem_cache_destroy(struct linux_kmem_cache *c) 194 { 195 if (c == NULL) 196 return; 197 198 if (unlikely(c->cache_flags & SLAB_TYPESAFE_BY_RCU)) { 199 /* make sure all free callbacks have been called */ 200 rcu_barrier(); 201 } 202 203 if (!llist_empty(&c->cache_items)) 204 taskqueue_enqueue(linux_irq_work_tq, &c->cache_task); 205 taskqueue_drain(linux_irq_work_tq, &c->cache_task); 206 uma_zdestroy(c->cache_zone); 207 free(c, M_KMALLOC); 208 } 209 210 void * 211 lkpi___kmalloc(size_t size, gfp_t flags) 212 { 213 size_t _s; 214 215 /* sizeof(struct llist_node) is used for kfree_async(). */ 216 _s = MAX(size, sizeof(struct llist_node)); 217 218 return (malloc(_s, M_KMALLOC, linux_check_m_flags(flags))); 219 } 220 221 struct lkpi_kmalloc_ctx { 222 size_t size; 223 gfp_t flags; 224 void *addr; 225 }; 226 227 static void 228 lkpi_kmalloc_cb(void *ctx) 229 { 230 struct lkpi_kmalloc_ctx *lmc = ctx; 231 232 lmc->addr = __kmalloc(lmc->size, lmc->flags); 233 } 234 235 void * 236 lkpi_kmalloc(size_t size, gfp_t flags) 237 { 238 struct lkpi_kmalloc_ctx lmc = { .size = size, .flags = flags }; 239 240 lkpi_fpu_safe_exec(&lkpi_kmalloc_cb, &lmc); 241 return(lmc.addr); 242 } 243 244 static void 245 linux_kfree_async_fn(void *context, int pending) 246 { 247 struct llist_node *freed; 248 249 while((freed = llist_del_first(&linux_kfree_async_list)) != NULL) 250 kfree(freed); 251 } 252 static struct task linux_kfree_async_task = 253 TASK_INITIALIZER(0, linux_kfree_async_fn, &linux_kfree_async_task); 254 255 void 256 linux_kfree_async(void *addr) 257 { 258 if (addr == NULL) 259 return; 260 llist_add(addr, &linux_kfree_async_list); 261 taskqueue_enqueue(linux_irq_work_tq, &linux_kfree_async_task); 262 } 263