1 /*- 2 * Copyright (c) 2013 The FreeBSD Foundation 3 * All rights reserved. 4 * 5 * This software was developed by Konstantin Belousov <kib@FreeBSD.org> 6 * under sponsorship from the FreeBSD Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/bus.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/malloc.h> 38 #include <sys/memdesc.h> 39 #include <sys/mutex.h> 40 #include <sys/proc.h> 41 #include <sys/queue.h> 42 #include <sys/rman.h> 43 #include <sys/rwlock.h> 44 #include <sys/sched.h> 45 #include <sys/sf_buf.h> 46 #include <sys/sysctl.h> 47 #include <sys/systm.h> 48 #include <sys/taskqueue.h> 49 #include <sys/tree.h> 50 #include <dev/pci/pcivar.h> 51 #include <vm/vm.h> 52 #include <vm/vm_extern.h> 53 #include <vm/vm_kern.h> 54 #include <vm/vm_object.h> 55 #include <vm/vm_page.h> 56 #include <vm/vm_map.h> 57 #include <vm/vm_pageout.h> 58 #include <machine/bus.h> 59 #include <machine/cpu.h> 60 #include <x86/include/busdma_impl.h> 61 #include <x86/iommu/intel_reg.h> 62 #include <x86/iommu/busdma_dmar.h> 63 #include <x86/iommu/intel_dmar.h> 64 65 u_int 66 dmar_nd2mask(u_int nd) 67 { 68 static const u_int masks[] = { 69 0x000f, /* nd == 0 */ 70 0x002f, /* nd == 1 */ 71 0x00ff, /* nd == 2 */ 72 0x02ff, /* nd == 3 */ 73 0x0fff, /* nd == 4 */ 74 0x2fff, /* nd == 5 */ 75 0xffff, /* nd == 6 */ 76 0x0000, /* nd == 7 reserved */ 77 }; 78 79 KASSERT(nd <= 6, ("number of domains %d", nd)); 80 return (masks[nd]); 81 } 82 83 static const struct sagaw_bits_tag { 84 int agaw; 85 int cap; 86 int awlvl; 87 int pglvl; 88 } sagaw_bits[] = { 89 {.agaw = 30, .cap = DMAR_CAP_SAGAW_2LVL, .awlvl = DMAR_CTX2_AW_2LVL, 90 .pglvl = 2}, 91 {.agaw = 39, .cap = DMAR_CAP_SAGAW_3LVL, .awlvl = DMAR_CTX2_AW_3LVL, 92 .pglvl = 3}, 93 {.agaw = 48, .cap = DMAR_CAP_SAGAW_4LVL, .awlvl = DMAR_CTX2_AW_4LVL, 94 .pglvl = 4}, 95 {.agaw = 57, .cap = DMAR_CAP_SAGAW_5LVL, .awlvl = DMAR_CTX2_AW_5LVL, 96 .pglvl = 5}, 97 {.agaw = 64, .cap = DMAR_CAP_SAGAW_6LVL, .awlvl = DMAR_CTX2_AW_6LVL, 98 .pglvl = 6} 99 }; 100 #define SIZEOF_SAGAW_BITS (sizeof(sagaw_bits) / sizeof(sagaw_bits[0])) 101 102 bool 103 dmar_pglvl_supported(struct dmar_unit *unit, int pglvl) 104 { 105 int i; 106 107 for (i = 0; i < SIZEOF_SAGAW_BITS; i++) { 108 if (sagaw_bits[i].pglvl != pglvl) 109 continue; 110 if ((DMAR_CAP_SAGAW(unit->hw_cap) & sagaw_bits[i].cap) != 0) 111 return (true); 112 } 113 return (false); 114 } 115 116 int 117 ctx_set_agaw(struct dmar_ctx *ctx, int mgaw) 118 { 119 int sagaw, i; 120 121 ctx->mgaw = mgaw; 122 sagaw = DMAR_CAP_SAGAW(ctx->dmar->hw_cap); 123 for (i = 0; i < SIZEOF_SAGAW_BITS; i++) { 124 if (sagaw_bits[i].agaw >= mgaw) { 125 ctx->agaw = sagaw_bits[i].agaw; 126 ctx->pglvl = sagaw_bits[i].pglvl; 127 ctx->awlvl = sagaw_bits[i].awlvl; 128 return (0); 129 } 130 } 131 device_printf(ctx->dmar->dev, 132 "context request mgaw %d for pci%d:%d:%d:%d, " 133 "no agaw found, sagaw %x\n", mgaw, ctx->dmar->segment, 134 pci_get_bus(ctx->ctx_tag.owner), 135 pci_get_slot(ctx->ctx_tag.owner), 136 pci_get_function(ctx->ctx_tag.owner), sagaw); 137 return (EINVAL); 138 } 139 140 /* 141 * Find a best fit mgaw for the given maxaddr: 142 * - if allow_less is false, must find sagaw which maps all requested 143 * addresses (used by identity mappings); 144 * - if allow_less is true, and no supported sagaw can map all requested 145 * address space, accept the biggest sagaw, whatever is it. 146 */ 147 int 148 dmar_maxaddr2mgaw(struct dmar_unit *unit, dmar_gaddr_t maxaddr, bool allow_less) 149 { 150 int i; 151 152 for (i = 0; i < SIZEOF_SAGAW_BITS; i++) { 153 if ((1ULL << sagaw_bits[i].agaw) >= maxaddr && 154 (DMAR_CAP_SAGAW(unit->hw_cap) & sagaw_bits[i].cap) != 0) 155 break; 156 } 157 if (allow_less && i == SIZEOF_SAGAW_BITS) { 158 do { 159 i--; 160 } while ((DMAR_CAP_SAGAW(unit->hw_cap) & sagaw_bits[i].cap) 161 == 0); 162 } 163 if (i < SIZEOF_SAGAW_BITS) 164 return (sagaw_bits[i].agaw); 165 KASSERT(0, ("no mgaw for maxaddr %jx allow_less %d", 166 (uintmax_t) maxaddr, allow_less)); 167 return (-1); 168 } 169 170 /* 171 * Calculate the total amount of page table pages needed to map the 172 * whole bus address space on the context with the selected agaw. 173 */ 174 vm_pindex_t 175 pglvl_max_pages(int pglvl) 176 { 177 vm_pindex_t res; 178 int i; 179 180 for (res = 0, i = pglvl; i > 0; i--) { 181 res *= DMAR_NPTEPG; 182 res++; 183 } 184 return (res); 185 } 186 187 /* 188 * Return true if the page table level lvl supports the superpage for 189 * the context ctx. 190 */ 191 int 192 ctx_is_sp_lvl(struct dmar_ctx *ctx, int lvl) 193 { 194 int alvl, cap_sps; 195 static const int sagaw_sp[] = { 196 DMAR_CAP_SPS_2M, 197 DMAR_CAP_SPS_1G, 198 DMAR_CAP_SPS_512G, 199 DMAR_CAP_SPS_1T 200 }; 201 202 alvl = ctx->pglvl - lvl - 1; 203 cap_sps = DMAR_CAP_SPS(ctx->dmar->hw_cap); 204 return (alvl < sizeof(sagaw_sp) / sizeof(sagaw_sp[0]) && 205 (sagaw_sp[alvl] & cap_sps) != 0); 206 } 207 208 dmar_gaddr_t 209 pglvl_page_size(int total_pglvl, int lvl) 210 { 211 int rlvl; 212 static const dmar_gaddr_t pg_sz[] = { 213 (dmar_gaddr_t)DMAR_PAGE_SIZE, 214 (dmar_gaddr_t)DMAR_PAGE_SIZE << DMAR_NPTEPGSHIFT, 215 (dmar_gaddr_t)DMAR_PAGE_SIZE << (2 * DMAR_NPTEPGSHIFT), 216 (dmar_gaddr_t)DMAR_PAGE_SIZE << (3 * DMAR_NPTEPGSHIFT), 217 (dmar_gaddr_t)DMAR_PAGE_SIZE << (4 * DMAR_NPTEPGSHIFT), 218 (dmar_gaddr_t)DMAR_PAGE_SIZE << (5 * DMAR_NPTEPGSHIFT) 219 }; 220 221 KASSERT(lvl >= 0 && lvl < total_pglvl, 222 ("total %d lvl %d", total_pglvl, lvl)); 223 rlvl = total_pglvl - lvl - 1; 224 KASSERT(rlvl < sizeof(pg_sz) / sizeof(pg_sz[0]), 225 ("sizeof pg_sz lvl %d", lvl)); 226 return (pg_sz[rlvl]); 227 } 228 229 dmar_gaddr_t 230 ctx_page_size(struct dmar_ctx *ctx, int lvl) 231 { 232 233 return (pglvl_page_size(ctx->pglvl, lvl)); 234 } 235 236 int 237 calc_am(struct dmar_unit *unit, dmar_gaddr_t base, dmar_gaddr_t size, 238 dmar_gaddr_t *isizep) 239 { 240 dmar_gaddr_t isize; 241 int am; 242 243 for (am = DMAR_CAP_MAMV(unit->hw_cap);; am--) { 244 isize = 1ULL << (am + DMAR_PAGE_SHIFT); 245 if ((base & (isize - 1)) == 0 && size >= isize) 246 break; 247 if (am == 0) 248 break; 249 } 250 *isizep = isize; 251 return (am); 252 } 253 254 dmar_haddr_t dmar_high; 255 int haw; 256 int dmar_tbl_pagecnt; 257 258 vm_page_t 259 dmar_pgalloc(vm_object_t obj, vm_pindex_t idx, int flags) 260 { 261 vm_page_t m; 262 int zeroed; 263 264 zeroed = (flags & DMAR_PGF_ZERO) != 0 ? VM_ALLOC_ZERO : 0; 265 for (;;) { 266 if ((flags & DMAR_PGF_OBJL) == 0) 267 VM_OBJECT_WLOCK(obj); 268 m = vm_page_lookup(obj, idx); 269 if ((flags & DMAR_PGF_NOALLOC) != 0 || m != NULL) { 270 if ((flags & DMAR_PGF_OBJL) == 0) 271 VM_OBJECT_WUNLOCK(obj); 272 break; 273 } 274 m = vm_page_alloc_contig(obj, idx, VM_ALLOC_NOBUSY | 275 VM_ALLOC_SYSTEM | VM_ALLOC_NODUMP | zeroed, 1, 0, 276 dmar_high, PAGE_SIZE, 0, VM_MEMATTR_DEFAULT); 277 if ((flags & DMAR_PGF_OBJL) == 0) 278 VM_OBJECT_WUNLOCK(obj); 279 if (m != NULL) { 280 if (zeroed && (m->flags & PG_ZERO) == 0) 281 pmap_zero_page(m); 282 atomic_add_int(&dmar_tbl_pagecnt, 1); 283 break; 284 } 285 if ((flags & DMAR_PGF_WAITOK) == 0) 286 break; 287 if ((flags & DMAR_PGF_OBJL) != 0) 288 VM_OBJECT_WUNLOCK(obj); 289 VM_WAIT; 290 if ((flags & DMAR_PGF_OBJL) != 0) 291 VM_OBJECT_WLOCK(obj); 292 } 293 return (m); 294 } 295 296 void 297 dmar_pgfree(vm_object_t obj, vm_pindex_t idx, int flags) 298 { 299 vm_page_t m; 300 301 if ((flags & DMAR_PGF_OBJL) == 0) 302 VM_OBJECT_WLOCK(obj); 303 m = vm_page_lookup(obj, idx); 304 if (m != NULL) { 305 vm_page_free(m); 306 atomic_subtract_int(&dmar_tbl_pagecnt, 1); 307 } 308 if ((flags & DMAR_PGF_OBJL) == 0) 309 VM_OBJECT_WUNLOCK(obj); 310 } 311 312 void * 313 dmar_map_pgtbl(vm_object_t obj, vm_pindex_t idx, int flags, 314 struct sf_buf **sf) 315 { 316 vm_page_t m; 317 bool allocated; 318 319 if ((flags & DMAR_PGF_OBJL) == 0) 320 VM_OBJECT_WLOCK(obj); 321 m = vm_page_lookup(obj, idx); 322 if (m == NULL && (flags & DMAR_PGF_ALLOC) != 0) { 323 m = dmar_pgalloc(obj, idx, flags | DMAR_PGF_OBJL); 324 allocated = true; 325 } else 326 allocated = false; 327 if (m == NULL) { 328 if ((flags & DMAR_PGF_OBJL) == 0) 329 VM_OBJECT_WUNLOCK(obj); 330 return (NULL); 331 } 332 /* Sleepable allocations cannot fail. */ 333 if ((flags & DMAR_PGF_WAITOK) != 0) 334 VM_OBJECT_WUNLOCK(obj); 335 sched_pin(); 336 *sf = sf_buf_alloc(m, SFB_CPUPRIVATE | ((flags & DMAR_PGF_WAITOK) 337 == 0 ? SFB_NOWAIT : 0)); 338 if (*sf == NULL) { 339 sched_unpin(); 340 if (allocated) { 341 VM_OBJECT_ASSERT_WLOCKED(obj); 342 dmar_pgfree(obj, m->pindex, flags | DMAR_PGF_OBJL); 343 } 344 if ((flags & DMAR_PGF_OBJL) == 0) 345 VM_OBJECT_WUNLOCK(obj); 346 return (NULL); 347 } 348 if ((flags & (DMAR_PGF_WAITOK | DMAR_PGF_OBJL)) == 349 (DMAR_PGF_WAITOK | DMAR_PGF_OBJL)) 350 VM_OBJECT_WLOCK(obj); 351 else if ((flags & (DMAR_PGF_WAITOK | DMAR_PGF_OBJL)) == 0) 352 VM_OBJECT_WUNLOCK(obj); 353 return ((void *)sf_buf_kva(*sf)); 354 } 355 356 void 357 dmar_unmap_pgtbl(struct sf_buf *sf) 358 { 359 360 sf_buf_free(sf); 361 sched_unpin(); 362 } 363 364 static void 365 dmar_flush_transl_to_ram(struct dmar_unit *unit, void *dst, size_t sz) 366 { 367 368 if (DMAR_IS_COHERENT(unit)) 369 return; 370 /* 371 * If DMAR does not snoop paging structures accesses, flush 372 * CPU cache to memory. 373 */ 374 pmap_invalidate_cache_range((uintptr_t)dst, (uintptr_t)dst + sz, 375 TRUE); 376 } 377 378 void 379 dmar_flush_pte_to_ram(struct dmar_unit *unit, dmar_pte_t *dst) 380 { 381 382 dmar_flush_transl_to_ram(unit, dst, sizeof(*dst)); 383 } 384 385 void 386 dmar_flush_ctx_to_ram(struct dmar_unit *unit, dmar_ctx_entry_t *dst) 387 { 388 389 dmar_flush_transl_to_ram(unit, dst, sizeof(*dst)); 390 } 391 392 void 393 dmar_flush_root_to_ram(struct dmar_unit *unit, dmar_root_entry_t *dst) 394 { 395 396 dmar_flush_transl_to_ram(unit, dst, sizeof(*dst)); 397 } 398 399 /* 400 * Load the root entry pointer into the hardware, busily waiting for 401 * the completion. 402 */ 403 int 404 dmar_load_root_entry_ptr(struct dmar_unit *unit) 405 { 406 vm_page_t root_entry; 407 408 /* 409 * Access to the GCMD register must be serialized while the 410 * command is submitted. 411 */ 412 DMAR_ASSERT_LOCKED(unit); 413 414 /* VM_OBJECT_RLOCK(unit->ctx_obj); */ 415 VM_OBJECT_WLOCK(unit->ctx_obj); 416 root_entry = vm_page_lookup(unit->ctx_obj, 0); 417 /* VM_OBJECT_RUNLOCK(unit->ctx_obj); */ 418 VM_OBJECT_WUNLOCK(unit->ctx_obj); 419 dmar_write8(unit, DMAR_RTADDR_REG, VM_PAGE_TO_PHYS(root_entry)); 420 dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd | DMAR_GCMD_SRTP); 421 /* XXXKIB should have a timeout */ 422 while ((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_RTPS) == 0) 423 cpu_spinwait(); 424 return (0); 425 } 426 427 /* 428 * Globally invalidate the context entries cache, busily waiting for 429 * the completion. 430 */ 431 int 432 dmar_inv_ctx_glob(struct dmar_unit *unit) 433 { 434 435 /* 436 * Access to the CCMD register must be serialized while the 437 * command is submitted. 438 */ 439 DMAR_ASSERT_LOCKED(unit); 440 KASSERT(!unit->qi_enabled, ("QI enabled")); 441 442 /* 443 * The DMAR_CCMD_ICC bit in the upper dword should be written 444 * after the low dword write is completed. Amd64 445 * dmar_write8() does not have this issue, i386 dmar_write8() 446 * writes the upper dword last. 447 */ 448 dmar_write8(unit, DMAR_CCMD_REG, DMAR_CCMD_ICC | DMAR_CCMD_CIRG_GLOB); 449 /* XXXKIB should have a timeout */ 450 while ((dmar_read4(unit, DMAR_CCMD_REG + 4) & DMAR_CCMD_ICC32) != 0) 451 cpu_spinwait(); 452 return (0); 453 } 454 455 /* 456 * Globally invalidate the IOTLB, busily waiting for the completion. 457 */ 458 int 459 dmar_inv_iotlb_glob(struct dmar_unit *unit) 460 { 461 int reg; 462 463 DMAR_ASSERT_LOCKED(unit); 464 KASSERT(!unit->qi_enabled, ("QI enabled")); 465 466 reg = 16 * DMAR_ECAP_IRO(unit->hw_ecap); 467 /* See a comment about DMAR_CCMD_ICC in dmar_inv_ctx_glob. */ 468 dmar_write8(unit, reg + DMAR_IOTLB_REG_OFF, DMAR_IOTLB_IVT | 469 DMAR_IOTLB_IIRG_GLB | DMAR_IOTLB_DR | DMAR_IOTLB_DW); 470 /* XXXKIB should have a timeout */ 471 while ((dmar_read4(unit, reg + DMAR_IOTLB_REG_OFF + 4) & 472 DMAR_IOTLB_IVT32) != 0) 473 cpu_spinwait(); 474 return (0); 475 } 476 477 /* 478 * Flush the chipset write buffers. See 11.1 "Write Buffer Flushing" 479 * in the architecture specification. 480 */ 481 int 482 dmar_flush_write_bufs(struct dmar_unit *unit) 483 { 484 485 DMAR_ASSERT_LOCKED(unit); 486 487 /* 488 * DMAR_GCMD_WBF is only valid when CAP_RWBF is reported. 489 */ 490 KASSERT((unit->hw_cap & DMAR_CAP_RWBF) != 0, 491 ("dmar%d: no RWBF", unit->unit)); 492 493 dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd | DMAR_GCMD_WBF); 494 /* XXXKIB should have a timeout */ 495 while ((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_WBFS) == 0) 496 cpu_spinwait(); 497 return (0); 498 } 499 500 int 501 dmar_enable_translation(struct dmar_unit *unit) 502 { 503 504 DMAR_ASSERT_LOCKED(unit); 505 unit->hw_gcmd |= DMAR_GCMD_TE; 506 dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd); 507 /* XXXKIB should have a timeout */ 508 while ((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_TES) == 0) 509 cpu_spinwait(); 510 return (0); 511 } 512 513 int 514 dmar_disable_translation(struct dmar_unit *unit) 515 { 516 517 DMAR_ASSERT_LOCKED(unit); 518 unit->hw_gcmd &= ~DMAR_GCMD_TE; 519 dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd); 520 /* XXXKIB should have a timeout */ 521 while ((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_TES) != 0) 522 cpu_spinwait(); 523 return (0); 524 } 525 526 #define BARRIER_F \ 527 u_int f_done, f_inproc, f_wakeup; \ 528 \ 529 f_done = 1 << (barrier_id * 3); \ 530 f_inproc = 1 << (barrier_id * 3 + 1); \ 531 f_wakeup = 1 << (barrier_id * 3 + 2) 532 533 bool 534 dmar_barrier_enter(struct dmar_unit *dmar, u_int barrier_id) 535 { 536 BARRIER_F; 537 538 DMAR_LOCK(dmar); 539 if ((dmar->barrier_flags & f_done) != 0) { 540 DMAR_UNLOCK(dmar); 541 return (false); 542 } 543 544 if ((dmar->barrier_flags & f_inproc) != 0) { 545 while ((dmar->barrier_flags & f_inproc) != 0) { 546 dmar->barrier_flags |= f_wakeup; 547 msleep(&dmar->barrier_flags, &dmar->lock, 0, 548 "dmarb", 0); 549 } 550 KASSERT((dmar->barrier_flags & f_done) != 0, 551 ("dmar%d barrier %d missing done", dmar->unit, barrier_id)); 552 DMAR_UNLOCK(dmar); 553 return (false); 554 } 555 556 dmar->barrier_flags |= f_inproc; 557 DMAR_UNLOCK(dmar); 558 return (true); 559 } 560 561 void 562 dmar_barrier_exit(struct dmar_unit *dmar, u_int barrier_id) 563 { 564 BARRIER_F; 565 566 DMAR_ASSERT_LOCKED(dmar); 567 KASSERT((dmar->barrier_flags & (f_done | f_inproc)) == f_inproc, 568 ("dmar%d barrier %d missed entry", dmar->unit, barrier_id)); 569 dmar->barrier_flags |= f_done; 570 if ((dmar->barrier_flags & f_wakeup) != 0) 571 wakeup(&dmar->barrier_flags); 572 dmar->barrier_flags &= ~(f_inproc | f_wakeup); 573 DMAR_UNLOCK(dmar); 574 } 575 576 int dmar_match_verbose; 577 578 static SYSCTL_NODE(_hw, OID_AUTO, dmar, CTLFLAG_RD, NULL, ""); 579 SYSCTL_INT(_hw_dmar, OID_AUTO, tbl_pagecnt, CTLFLAG_RD, 580 &dmar_tbl_pagecnt, 0, 581 "Count of pages used for DMAR pagetables"); 582 SYSCTL_INT(_hw_dmar, OID_AUTO, match_verbose, CTLFLAG_RWTUN, 583 &dmar_match_verbose, 0, 584 "Verbose matching of the PCI devices to DMAR paths"); 585 #ifdef INVARIANTS 586 int dmar_check_free; 587 SYSCTL_INT(_hw_dmar, OID_AUTO, check_free, CTLFLAG_RWTUN, 588 &dmar_check_free, 0, 589 "Check the GPA RBtree for free_down and free_after validity"); 590 #endif 591 592