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