kernel/freebsd/contigmem/contigmem.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2014 Intel Corporation
   3  */
   4
   5 #include <sys/cdefs.h>
   6 __FBSDID("$FreeBSD$");
   7
   8 #include <sys/param.h>
   9 #include <sys/bio.h>
  10 #include <sys/bus.h>
  11 #include <sys/conf.h>
  12 #include <sys/kernel.h>
  13 #include <sys/malloc.h>
  14 #include <sys/module.h>
  15 #include <sys/proc.h>
  16 #include <sys/lock.h>
  17 #include <sys/rwlock.h>
  18 #include <sys/mutex.h>
  19 #include <sys/systm.h>
  20 #include <sys/sysctl.h>
  21 #include <sys/vmmeter.h>
  22 #include <sys/eventhandler.h>
  23
  24 #include <machine/bus.h>
  25
  26 #include <vm/vm.h>
  27 #include <vm/pmap.h>
  28 #include <vm/vm_param.h>
  29 #include <vm/vm_object.h>
  30 #include <vm/vm_page.h>
  31 #include <vm/vm_pager.h>
  32 #include <vm/vm_phys.h>
  33
  34 struct contigmem_buffer {
  35         void           *addr;
  36         int             refcnt;
  37         struct mtx      mtx;
  38 };
  39
  40 struct contigmem_vm_handle {
  41         int             buffer_index;
  42 };
  43
  44 static int              contigmem_load(void);
  45 static int              contigmem_unload(void);
  46 static int              contigmem_physaddr(SYSCTL_HANDLER_ARGS);
  47
  48 static d_mmap_single_t  contigmem_mmap_single;
  49 static d_open_t         contigmem_open;
  50 static d_close_t        contigmem_close;
  51
  52 static int              contigmem_num_buffers = RTE_CONTIGMEM_DEFAULT_NUM_BUFS;
  53 static int64_t          contigmem_buffer_size = RTE_CONTIGMEM_DEFAULT_BUF_SIZE;
  54
  55 static eventhandler_tag contigmem_eh_tag;
  56 static struct contigmem_buffer contigmem_buffers[RTE_CONTIGMEM_MAX_NUM_BUFS];
  57 static struct cdev     *contigmem_cdev = NULL;
  58 static int              contigmem_refcnt;
  59
  60 TUNABLE_INT("hw.contigmem.num_buffers", &contigmem_num_buffers);
  61 TUNABLE_QUAD("hw.contigmem.buffer_size", &contigmem_buffer_size);
  62
  63 static SYSCTL_NODE(_hw, OID_AUTO, contigmem, CTLFLAG_RD, 0, "contigmem");
  64
  65 SYSCTL_INT(_hw_contigmem, OID_AUTO, num_buffers, CTLFLAG_RD,
  66         &contigmem_num_buffers, 0, "Number of contigmem buffers allocated");
  67 SYSCTL_QUAD(_hw_contigmem, OID_AUTO, buffer_size, CTLFLAG_RD,
  68         &contigmem_buffer_size, 0, "Size of each contiguous buffer");
  69 SYSCTL_INT(_hw_contigmem, OID_AUTO, num_references, CTLFLAG_RD,
  70         &contigmem_refcnt, 0, "Number of references to contigmem");
  71
  72 static SYSCTL_NODE(_hw_contigmem, OID_AUTO, physaddr, CTLFLAG_RD, 0,
  73         "physaddr");
  74
  75 MALLOC_DEFINE(M_CONTIGMEM, "contigmem", "contigmem(4) allocations");
  76
  77 static int contigmem_modevent(module_t mod, int type, void *arg)
  78 {
  79         int error = 0;
  80
  81         switch (type) {
  82         case MOD_LOAD:
  83                 error = contigmem_load();
  84                 break;
  85         case MOD_UNLOAD:
  86                 error = contigmem_unload();
  87                 break;
  88         default:
  89                 break;
  90         }
  91
  92         return error;
  93 }
  94
  95 moduledata_t contigmem_mod = {
  96         "contigmem",
  97         (modeventhand_t)contigmem_modevent,
  98         0
  99 };
 100
 101 DECLARE_MODULE(contigmem, contigmem_mod, SI_SUB_DRIVERS, SI_ORDER_ANY);
 102 MODULE_VERSION(contigmem, 1);
 103
 104 static struct cdevsw contigmem_ops = {
 105         .d_name         = "contigmem",
 106         .d_version      = D_VERSION,
 107         .d_flags        = D_TRACKCLOSE,
 108         .d_mmap_single  = contigmem_mmap_single,
 109         .d_open         = contigmem_open,
 110         .d_close        = contigmem_close,
 111 };
 112
 113 static int
 114 contigmem_load()
 115 {
 116         char index_string[8], description[32];
 117         int  i, error = 0;
 118         void *addr;
 119
 120         if (contigmem_num_buffers > RTE_CONTIGMEM_MAX_NUM_BUFS) {
 121                 printf("%d buffers requested is greater than %d allowed\n",
 122                                 contigmem_num_buffers, RTE_CONTIGMEM_MAX_NUM_BUFS);
 123                 error = EINVAL;
 124                 goto error;
 125         }
 126
 127         if (contigmem_buffer_size < PAGE_SIZE ||
 128                         (contigmem_buffer_size & (contigmem_buffer_size - 1)) != 0) {
 129                 printf("buffer size 0x%lx is not greater than PAGE_SIZE and "
 130                                 "power of two\n", contigmem_buffer_size);
 131                 error = EINVAL;
 132                 goto error;
 133         }
 134
 135         for (i = 0; i < contigmem_num_buffers; i++) {
 136                 addr = contigmalloc(contigmem_buffer_size, M_CONTIGMEM, M_ZERO,
 137                         0, BUS_SPACE_MAXADDR, contigmem_buffer_size, 0);
 138                 if (addr == NULL) {
 139                         printf("contigmalloc failed for buffer %d\n", i);
 140                         error = ENOMEM;
 141                         goto error;
 142                 }
 143
 144                 printf("%2u: virt=%p phys=%p\n", i, addr,
 145                         (void *)pmap_kextract((vm_offset_t)addr));
 146
 147                 mtx_init(&contigmem_buffers[i].mtx, "contigmem", NULL, MTX_DEF);
 148                 contigmem_buffers[i].addr = addr;
 149                 contigmem_buffers[i].refcnt = 0;
 150
 151                 snprintf(index_string, sizeof(index_string), "%d", i);
 152                 snprintf(description, sizeof(description),
 153                                 "phys addr for buffer %d", i);
 154                 SYSCTL_ADD_PROC(NULL,
 155                                 &SYSCTL_NODE_CHILDREN(_hw_contigmem, physaddr), OID_AUTO,
 156                                 index_string, CTLTYPE_U64 | CTLFLAG_RD,
 157                                 (void *)(uintptr_t)i, 0, contigmem_physaddr, "LU",
 158                                 description);
 159         }
 160
 161         contigmem_cdev = make_dev_credf(0, &contigmem_ops, 0, NULL, UID_ROOT,
 162                         GID_WHEEL, 0600, "contigmem");
 163
 164         return 0;
 165
 166 error:
 167         for (i = 0; i < contigmem_num_buffers; i++) {
 168                 if (contigmem_buffers[i].addr != NULL) {
 169                         contigfree(contigmem_buffers[i].addr,
 170                                 contigmem_buffer_size, M_CONTIGMEM);
 171                         contigmem_buffers[i].addr = NULL;
 172                 }
 173                 if (mtx_initialized(&contigmem_buffers[i].mtx))
 174                         mtx_destroy(&contigmem_buffers[i].mtx);
 175         }
 176
 177         return error;
 178 }
 179
 180 static int
 181 contigmem_unload()
 182 {
 183         int i;
 184
 185         if (contigmem_refcnt > 0)
 186                 return EBUSY;
 187
 188         if (contigmem_cdev != NULL)
 189                 destroy_dev(contigmem_cdev);
 190
 191         if (contigmem_eh_tag != NULL)
 192                 EVENTHANDLER_DEREGISTER(process_exit, contigmem_eh_tag);
 193
 194         for (i = 0; i < RTE_CONTIGMEM_MAX_NUM_BUFS; i++) {
 195                 if (contigmem_buffers[i].addr != NULL)
 196                         contigfree(contigmem_buffers[i].addr,
 197                                 contigmem_buffer_size, M_CONTIGMEM);
 198                 if (mtx_initialized(&contigmem_buffers[i].mtx))
 199                         mtx_destroy(&contigmem_buffers[i].mtx);
 200         }
 201
 202         return 0;
 203 }
 204
 205 static int
 206 contigmem_physaddr(SYSCTL_HANDLER_ARGS)
 207 {
 208         uint64_t        physaddr;
 209         int             index = (int)(uintptr_t)arg1;
 210
 211         physaddr = (uint64_t)vtophys(contigmem_buffers[index].addr);
 212         return sysctl_handle_64(oidp, &physaddr, 0, req);
 213 }
 214
 215 static int
 216 contigmem_open(struct cdev *cdev, int fflags, int devtype,
 217                 struct thread *td)
 218 {
 219
 220         atomic_add_int(&contigmem_refcnt, 1);
 221
 222         return 0;
 223 }
 224
 225 static int
 226 contigmem_close(struct cdev *cdev, int fflags, int devtype,
 227                 struct thread *td)
 228 {
 229
 230         atomic_subtract_int(&contigmem_refcnt, 1);
 231
 232         return 0;
 233 }
 234
 235 static int
 236 contigmem_cdev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
 237                 vm_ooffset_t foff, struct ucred *cred, u_short *color)
 238 {
 239         struct contigmem_vm_handle *vmh = handle;
 240         struct contigmem_buffer *buf;
 241
 242         buf = &contigmem_buffers[vmh->buffer_index];
 243
 244         atomic_add_int(&contigmem_refcnt, 1);
 245
 246         mtx_lock(&buf->mtx);
 247         if (buf->refcnt == 0)
 248                 memset(buf->addr, 0, contigmem_buffer_size);
 249         buf->refcnt++;
 250         mtx_unlock(&buf->mtx);
 251
 252         return 0;
 253 }
 254
 255 static void
 256 contigmem_cdev_pager_dtor(void *handle)
 257 {
 258         struct contigmem_vm_handle *vmh = handle;
 259         struct contigmem_buffer *buf;
 260
 261         buf = &contigmem_buffers[vmh->buffer_index];
 262
 263         mtx_lock(&buf->mtx);
 264         buf->refcnt--;
 265         mtx_unlock(&buf->mtx);
 266
 267         free(vmh, M_CONTIGMEM);
 268
 269         atomic_subtract_int(&contigmem_refcnt, 1);
 270 }
 271
 272 static int
 273 contigmem_cdev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot,
 274                 vm_page_t *mres)
 275 {
 276         vm_paddr_t paddr;
 277         vm_page_t m_paddr, page;
 278         vm_memattr_t memattr, memattr1;
 279
 280         memattr = object->memattr;
 281
 282         VM_OBJECT_WUNLOCK(object);
 283
 284         paddr = offset;
 285
 286         m_paddr = vm_phys_paddr_to_vm_page(paddr);
 287         if (m_paddr != NULL) {
 288                 memattr1 = pmap_page_get_memattr(m_paddr);
 289                 if (memattr1 != memattr)
 290                         memattr = memattr1;
 291         }
 292
 293         if (((*mres)->flags & PG_FICTITIOUS) != 0) {
 294                 /*
 295                  * If the passed in result page is a fake page, update it with
 296                  * the new physical address.
 297                  */
 298                 page = *mres;
 299                 VM_OBJECT_WLOCK(object);
 300                 vm_page_updatefake(page, paddr, memattr);
 301         } else {
 302                 /*
 303                  * Replace the passed in reqpage page with our own fake page and
 304                  * free up the original page.
 305                  */
 306                 page = vm_page_getfake(paddr, memattr);
 307                 VM_OBJECT_WLOCK(object);
 308 #if __FreeBSD__ >= 13
 309                 vm_page_replace(page, object, (*mres)->pindex, *mres);
 310 #else
 311                 vm_page_t mret = vm_page_replace(page, object, (*mres)->pindex);
 312                 KASSERT(mret == *mres,
 313                     ("invalid page replacement, old=%p, ret=%p", *mres, mret));
 314                 vm_page_lock(mret);
 315                 vm_page_free(mret);
 316                 vm_page_unlock(mret);
 317 #endif
 318                 *mres = page;
 319         }
 320
 321         page->valid = VM_PAGE_BITS_ALL;
 322
 323         return VM_PAGER_OK;
 324 }
 325
 326 static struct cdev_pager_ops contigmem_cdev_pager_ops = {
 327         .cdev_pg_ctor = contigmem_cdev_pager_ctor,
 328         .cdev_pg_dtor = contigmem_cdev_pager_dtor,
 329         .cdev_pg_fault = contigmem_cdev_pager_fault,
 330 };
 331
 332 static int
 333 contigmem_mmap_single(struct cdev *cdev, vm_ooffset_t *offset, vm_size_t size,
 334                 struct vm_object **obj, int nprot)
 335 {
 336         struct contigmem_vm_handle *vmh;
 337         uint64_t buffer_index;
 338
 339         /*
 340          * The buffer index is encoded in the offset.  Divide the offset by
 341          *  PAGE_SIZE to get the index of the buffer requested by the user
 342          *  app.
 343          */
 344         buffer_index = *offset / PAGE_SIZE;
 345         if (buffer_index >= contigmem_num_buffers)
 346                 return EINVAL;
 347
 348         if (size > contigmem_buffer_size)
 349                 return EINVAL;
 350
 351         vmh = malloc(sizeof(*vmh), M_CONTIGMEM, M_NOWAIT | M_ZERO);
 352         if (vmh == NULL)
 353                 return ENOMEM;
 354         vmh->buffer_index = buffer_index;
 355
 356         *offset = (vm_ooffset_t)vtophys(contigmem_buffers[buffer_index].addr);
 357         *obj = cdev_pager_allocate(vmh, OBJT_DEVICE, &contigmem_cdev_pager_ops,
 358                         size, nprot, *offset, curthread->td_ucred);
 359
 360         return 0;
 361 }