1 // SPDX-License-Identifier: GPL-2.0 2 3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved. 4 * Copyright (C) 2018-2020 Linaro Ltd. 5 */ 6 7 #include <linux/types.h> 8 #include <linux/kernel.h> 9 #include <linux/bits.h> 10 #include <linux/bitops.h> 11 #include <linux/bitfield.h> 12 #include <linux/io.h> 13 #include <linux/build_bug.h> 14 #include <linux/device.h> 15 #include <linux/dma-mapping.h> 16 17 #include "ipa.h" 18 #include "ipa_version.h" 19 #include "ipa_endpoint.h" 20 #include "ipa_table.h" 21 #include "ipa_reg.h" 22 #include "ipa_mem.h" 23 #include "ipa_cmd.h" 24 #include "gsi.h" 25 #include "gsi_trans.h" 26 27 /** 28 * DOC: IPA Filter and Route Tables 29 * 30 * The IPA has tables defined in its local shared memory that define filter 31 * and routing rules. Each entry in these tables contains a 64-bit DMA 32 * address that refers to DRAM (system memory) containing a rule definition. 33 * A rule consists of a contiguous block of 32-bit values terminated with 34 * 32 zero bits. A special "zero entry" rule consisting of 64 zero bits 35 * represents "no filtering" or "no routing," and is the reset value for 36 * filter or route table rules. Separate tables (both filter and route) 37 * used for IPv4 and IPv6. Additionally, there can be hashed filter or 38 * route tables, which are used when a hash of message metadata matches. 39 * Hashed operation is not supported by all IPA hardware. 40 * 41 * Each filter rule is associated with an AP or modem TX endpoint, though 42 * not all TX endpoints support filtering. The first 64-bit entry in a 43 * filter table is a bitmap indicating which endpoints have entries in 44 * the table. The low-order bit (bit 0) in this bitmap represents a 45 * special global filter, which applies to all traffic. This is not 46 * used in the current code. Bit 1, if set, indicates that there is an 47 * entry (i.e. a DMA address referring to a rule) for endpoint 0 in the 48 * table. Bit 2, if set, indicates there is an entry for endpoint 1, 49 * and so on. Space is set aside in IPA local memory to hold as many 50 * filter table entries as might be required, but typically they are not 51 * all used. 52 * 53 * The AP initializes all entries in a filter table to refer to a "zero" 54 * entry. Once initialized the modem and AP update the entries for 55 * endpoints they "own" directly. Currently the AP does not use the 56 * IPA filtering functionality. 57 * 58 * IPA Filter Table 59 * ---------------------- 60 * endpoint bitmap | 0x0000000000000048 | Bits 3 and 6 set (endpoints 2 and 5) 61 * |--------------------| 62 * 1st endpoint | 0x000123456789abc0 | DMA address for modem endpoint 2 rule 63 * |--------------------| 64 * 2nd endpoint | 0x000123456789abf0 | DMA address for AP endpoint 5 rule 65 * |--------------------| 66 * (unused) | | (Unused space in filter table) 67 * |--------------------| 68 * . . . 69 * |--------------------| 70 * (unused) | | (Unused space in filter table) 71 * ---------------------- 72 * 73 * The set of available route rules is divided about equally between the AP 74 * and modem. The AP initializes all entries in a route table to refer to 75 * a "zero entry". Once initialized, the modem and AP are responsible for 76 * updating their own entries. All entries in a route table are usable, 77 * though the AP currently does not use the IPA routing functionality. 78 * 79 * IPA Route Table 80 * ---------------------- 81 * 1st modem route | 0x0001234500001100 | DMA address for first route rule 82 * |--------------------| 83 * 2nd modem route | 0x0001234500001140 | DMA address for second route rule 84 * |--------------------| 85 * . . . 86 * |--------------------| 87 * Last modem route| 0x0001234500002280 | DMA address for Nth route rule 88 * |--------------------| 89 * 1st AP route | 0x0001234500001100 | DMA address for route rule (N+1) 90 * |--------------------| 91 * 2nd AP route | 0x0001234500001140 | DMA address for next route rule 92 * |--------------------| 93 * . . . 94 * |--------------------| 95 * Last AP route | 0x0001234500002280 | DMA address for last route rule 96 * ---------------------- 97 */ 98 99 /* IPA hardware constrains filter and route tables alignment */ 100 #define IPA_TABLE_ALIGN 128 /* Minimum table alignment */ 101 102 /* Assignment of route table entries to the modem and AP */ 103 #define IPA_ROUTE_MODEM_MIN 0 104 #define IPA_ROUTE_MODEM_COUNT 8 105 106 #define IPA_ROUTE_AP_MIN IPA_ROUTE_MODEM_COUNT 107 #define IPA_ROUTE_AP_COUNT \ 108 (IPA_ROUTE_COUNT_MAX - IPA_ROUTE_MODEM_COUNT) 109 110 /* Filter or route rules consist of a set of 32-bit values followed by a 111 * 32-bit all-zero rule list terminator. The "zero rule" is simply an 112 * all-zero rule followed by the list terminator. 113 */ 114 #define IPA_ZERO_RULE_SIZE (2 * sizeof(__le32)) 115 116 #ifdef IPA_VALIDATE 117 118 /* Check things that can be validated at build time. */ 119 static void ipa_table_validate_build(void) 120 { 121 /* IPA hardware accesses memory 128 bytes at a time. Addresses 122 * referred to by entries in filter and route tables must be 123 * aligned on 128-byte byte boundaries. The only rule address 124 * ever use is the "zero rule", and it's aligned at the base 125 * of a coherent DMA allocation. 126 */ 127 BUILD_BUG_ON(ARCH_DMA_MINALIGN % IPA_TABLE_ALIGN); 128 129 /* Filter and route tables contain DMA addresses that refer to 130 * filter or route rules. We use a fixed constant to represent 131 * the size of either type of table entry. Code in ipa_table_init() 132 * uses a pointer to __le64 to initialize table entriews. 133 */ 134 BUILD_BUG_ON(IPA_TABLE_ENTRY_SIZE != sizeof(dma_addr_t)); 135 BUILD_BUG_ON(sizeof(dma_addr_t) != sizeof(__le64)); 136 137 /* A "zero rule" is used to represent no filtering or no routing. 138 * It is a 64-bit block of zeroed memory. Code in ipa_table_init() 139 * assumes that it can be written using a pointer to __le64. 140 */ 141 BUILD_BUG_ON(IPA_ZERO_RULE_SIZE != sizeof(__le64)); 142 143 /* Impose a practical limit on the number of routes */ 144 BUILD_BUG_ON(IPA_ROUTE_COUNT_MAX > 32); 145 /* The modem must be allotted at least one route table entry */ 146 BUILD_BUG_ON(!IPA_ROUTE_MODEM_COUNT); 147 /* But it can't have more than what is available */ 148 BUILD_BUG_ON(IPA_ROUTE_MODEM_COUNT > IPA_ROUTE_COUNT_MAX); 149 150 } 151 152 static bool 153 ipa_table_valid_one(struct ipa *ipa, bool route, bool ipv6, bool hashed) 154 { 155 struct device *dev = &ipa->pdev->dev; 156 const struct ipa_mem *mem; 157 u32 size; 158 159 if (route) { 160 if (ipv6) 161 mem = hashed ? &ipa->mem[IPA_MEM_V6_ROUTE_HASHED] 162 : &ipa->mem[IPA_MEM_V6_ROUTE]; 163 else 164 mem = hashed ? &ipa->mem[IPA_MEM_V4_ROUTE_HASHED] 165 : &ipa->mem[IPA_MEM_V4_ROUTE]; 166 size = IPA_ROUTE_COUNT_MAX * IPA_TABLE_ENTRY_SIZE; 167 } else { 168 if (ipv6) 169 mem = hashed ? &ipa->mem[IPA_MEM_V6_FILTER_HASHED] 170 : &ipa->mem[IPA_MEM_V6_FILTER]; 171 else 172 mem = hashed ? &ipa->mem[IPA_MEM_V4_FILTER_HASHED] 173 : &ipa->mem[IPA_MEM_V4_FILTER]; 174 size = (1 + IPA_FILTER_COUNT_MAX) * IPA_TABLE_ENTRY_SIZE; 175 } 176 177 if (!ipa_cmd_table_valid(ipa, mem, route, ipv6, hashed)) 178 return false; 179 180 /* mem->size >= size is sufficient, but we'll demand more */ 181 if (mem->size == size) 182 return true; 183 184 /* Hashed table regions can be zero size if hashing is not supported */ 185 if (hashed && !mem->size) 186 return true; 187 188 dev_err(dev, "IPv%c %s%s table region size 0x%02x, expected 0x%02x\n", 189 ipv6 ? '6' : '4', hashed ? "hashed " : "", 190 route ? "route" : "filter", mem->size, size); 191 192 return false; 193 } 194 195 /* Verify the filter and route table memory regions are the expected size */ 196 bool ipa_table_valid(struct ipa *ipa) 197 { 198 bool valid = true; 199 200 valid = valid && ipa_table_valid_one(ipa, false, false, false); 201 valid = valid && ipa_table_valid_one(ipa, false, false, true); 202 valid = valid && ipa_table_valid_one(ipa, false, true, false); 203 valid = valid && ipa_table_valid_one(ipa, false, true, true); 204 valid = valid && ipa_table_valid_one(ipa, true, false, false); 205 valid = valid && ipa_table_valid_one(ipa, true, false, true); 206 valid = valid && ipa_table_valid_one(ipa, true, true, false); 207 valid = valid && ipa_table_valid_one(ipa, true, true, true); 208 209 return valid; 210 } 211 212 bool ipa_filter_map_valid(struct ipa *ipa, u32 filter_map) 213 { 214 struct device *dev = &ipa->pdev->dev; 215 u32 count; 216 217 if (!filter_map) { 218 dev_err(dev, "at least one filtering endpoint is required\n"); 219 220 return false; 221 } 222 223 count = hweight32(filter_map); 224 if (count > IPA_FILTER_COUNT_MAX) { 225 dev_err(dev, "too many filtering endpoints (%u, max %u)\n", 226 count, IPA_FILTER_COUNT_MAX); 227 228 return false; 229 } 230 231 return true; 232 } 233 234 #else /* !IPA_VALIDATE */ 235 static void ipa_table_validate_build(void) 236 237 { 238 } 239 240 #endif /* !IPA_VALIDATE */ 241 242 /* Zero entry count means no table, so just return a 0 address */ 243 static dma_addr_t ipa_table_addr(struct ipa *ipa, bool filter_mask, u16 count) 244 { 245 u32 skip; 246 247 if (!count) 248 return 0; 249 250 /* assert(count <= max_t(u32, IPA_FILTER_COUNT_MAX, IPA_ROUTE_COUNT_MAX)); */ 251 252 /* Skip over the zero rule and possibly the filter mask */ 253 skip = filter_mask ? 1 : 2; 254 255 return ipa->table_addr + skip * sizeof(*ipa->table_virt); 256 } 257 258 static void ipa_table_reset_add(struct gsi_trans *trans, bool filter, 259 u16 first, u16 count, const struct ipa_mem *mem) 260 { 261 struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi); 262 dma_addr_t addr; 263 u32 offset; 264 u16 size; 265 266 /* Nothing to do if the table memory regions is empty */ 267 if (!mem->size) 268 return; 269 270 if (filter) 271 first++; /* skip over bitmap */ 272 273 offset = mem->offset + first * IPA_TABLE_ENTRY_SIZE; 274 size = count * IPA_TABLE_ENTRY_SIZE; 275 addr = ipa_table_addr(ipa, false, count); 276 277 ipa_cmd_dma_shared_mem_add(trans, offset, size, addr, true); 278 } 279 280 /* Reset entries in a single filter table belonging to either the AP or 281 * modem to refer to the zero entry. The memory region supplied will be 282 * for the IPv4 and IPv6 non-hashed and hashed filter tables. 283 */ 284 static int 285 ipa_filter_reset_table(struct ipa *ipa, const struct ipa_mem *mem, bool modem) 286 { 287 u32 ep_mask = ipa->filter_map; 288 u32 count = hweight32(ep_mask); 289 struct gsi_trans *trans; 290 enum gsi_ee_id ee_id; 291 292 if (!mem->size) 293 return 0; 294 295 trans = ipa_cmd_trans_alloc(ipa, count); 296 if (!trans) { 297 dev_err(&ipa->pdev->dev, 298 "no transaction for %s filter reset\n", 299 modem ? "modem" : "AP"); 300 return -EBUSY; 301 } 302 303 ee_id = modem ? GSI_EE_MODEM : GSI_EE_AP; 304 while (ep_mask) { 305 u32 endpoint_id = __ffs(ep_mask); 306 struct ipa_endpoint *endpoint; 307 308 ep_mask ^= BIT(endpoint_id); 309 310 endpoint = &ipa->endpoint[endpoint_id]; 311 if (endpoint->ee_id != ee_id) 312 continue; 313 314 ipa_table_reset_add(trans, true, endpoint_id, 1, mem); 315 } 316 317 gsi_trans_commit_wait(trans); 318 319 return 0; 320 } 321 322 /* Theoretically, each filter table could have more filter slots to 323 * update than the maximum number of commands in a transaction. So 324 * we do each table separately. 325 */ 326 static int ipa_filter_reset(struct ipa *ipa, bool modem) 327 { 328 int ret; 329 330 ret = ipa_filter_reset_table(ipa, &ipa->mem[IPA_MEM_V4_FILTER], modem); 331 if (ret) 332 return ret; 333 334 ret = ipa_filter_reset_table(ipa, &ipa->mem[IPA_MEM_V4_FILTER_HASHED], 335 modem); 336 if (ret) 337 return ret; 338 339 ret = ipa_filter_reset_table(ipa, &ipa->mem[IPA_MEM_V6_FILTER], modem); 340 if (ret) 341 return ret; 342 ret = ipa_filter_reset_table(ipa, &ipa->mem[IPA_MEM_V6_FILTER_HASHED], 343 modem); 344 345 return ret; 346 } 347 348 /* The AP routes and modem routes are each contiguous within the 349 * table. We can update each table with a single command, and we 350 * won't exceed the per-transaction command limit. 351 * */ 352 static int ipa_route_reset(struct ipa *ipa, bool modem) 353 { 354 struct gsi_trans *trans; 355 u16 first; 356 u16 count; 357 358 trans = ipa_cmd_trans_alloc(ipa, 4); 359 if (!trans) { 360 dev_err(&ipa->pdev->dev, 361 "no transaction for %s route reset\n", 362 modem ? "modem" : "AP"); 363 return -EBUSY; 364 } 365 366 if (modem) { 367 first = IPA_ROUTE_MODEM_MIN; 368 count = IPA_ROUTE_MODEM_COUNT; 369 } else { 370 first = IPA_ROUTE_AP_MIN; 371 count = IPA_ROUTE_AP_COUNT; 372 } 373 374 ipa_table_reset_add(trans, false, first, count, 375 &ipa->mem[IPA_MEM_V4_ROUTE]); 376 ipa_table_reset_add(trans, false, first, count, 377 &ipa->mem[IPA_MEM_V4_ROUTE_HASHED]); 378 379 ipa_table_reset_add(trans, false, first, count, 380 &ipa->mem[IPA_MEM_V6_ROUTE]); 381 ipa_table_reset_add(trans, false, first, count, 382 &ipa->mem[IPA_MEM_V6_ROUTE_HASHED]); 383 384 gsi_trans_commit_wait(trans); 385 386 return 0; 387 } 388 389 void ipa_table_reset(struct ipa *ipa, bool modem) 390 { 391 struct device *dev = &ipa->pdev->dev; 392 const char *ee_name; 393 int ret; 394 395 ee_name = modem ? "modem" : "AP"; 396 397 /* Report errors, but reset filter and route tables */ 398 ret = ipa_filter_reset(ipa, modem); 399 if (ret) 400 dev_err(dev, "error %d resetting filter table for %s\n", 401 ret, ee_name); 402 403 ret = ipa_route_reset(ipa, modem); 404 if (ret) 405 dev_err(dev, "error %d resetting route table for %s\n", 406 ret, ee_name); 407 } 408 409 int ipa_table_hash_flush(struct ipa *ipa) 410 { 411 u32 offset = ipa_reg_filt_rout_hash_flush_offset(ipa->version); 412 struct gsi_trans *trans; 413 u32 val; 414 415 /* IPA version 4.2 does not support hashed tables */ 416 if (ipa->version == IPA_VERSION_4_2) 417 return 0; 418 419 trans = ipa_cmd_trans_alloc(ipa, 1); 420 if (!trans) { 421 dev_err(&ipa->pdev->dev, "no transaction for hash flush\n"); 422 return -EBUSY; 423 } 424 425 val = IPV4_FILTER_HASH_FLUSH | IPV6_FILTER_HASH_FLUSH; 426 val |= IPV6_ROUTER_HASH_FLUSH | IPV4_ROUTER_HASH_FLUSH; 427 428 ipa_cmd_register_write_add(trans, offset, val, val, false); 429 430 gsi_trans_commit_wait(trans); 431 432 return 0; 433 } 434 435 static void ipa_table_init_add(struct gsi_trans *trans, bool filter, 436 enum ipa_cmd_opcode opcode, 437 const struct ipa_mem *mem, 438 const struct ipa_mem *hash_mem) 439 { 440 struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi); 441 dma_addr_t hash_addr; 442 dma_addr_t addr; 443 u16 hash_count; 444 u16 hash_size; 445 u16 count; 446 u16 size; 447 448 /* The number of filtering endpoints determines number of entries 449 * in the filter table. The hashed and non-hashed filter table 450 * will have the same number of entries. The size of the route 451 * table region determines the number of entries it has. 452 */ 453 if (filter) { 454 count = hweight32(ipa->filter_map); 455 hash_count = hash_mem->size ? count : 0; 456 } else { 457 count = mem->size / IPA_TABLE_ENTRY_SIZE; 458 hash_count = hash_mem->size / IPA_TABLE_ENTRY_SIZE; 459 } 460 size = count * IPA_TABLE_ENTRY_SIZE; 461 hash_size = hash_count * IPA_TABLE_ENTRY_SIZE; 462 463 addr = ipa_table_addr(ipa, filter, count); 464 hash_addr = ipa_table_addr(ipa, filter, hash_count); 465 466 ipa_cmd_table_init_add(trans, opcode, size, mem->offset, addr, 467 hash_size, hash_mem->offset, hash_addr); 468 } 469 470 int ipa_table_setup(struct ipa *ipa) 471 { 472 struct gsi_trans *trans; 473 474 trans = ipa_cmd_trans_alloc(ipa, 4); 475 if (!trans) { 476 dev_err(&ipa->pdev->dev, "no transaction for table setup\n"); 477 return -EBUSY; 478 } 479 480 ipa_table_init_add(trans, false, IPA_CMD_IP_V4_ROUTING_INIT, 481 &ipa->mem[IPA_MEM_V4_ROUTE], 482 &ipa->mem[IPA_MEM_V4_ROUTE_HASHED]); 483 484 ipa_table_init_add(trans, false, IPA_CMD_IP_V6_ROUTING_INIT, 485 &ipa->mem[IPA_MEM_V6_ROUTE], 486 &ipa->mem[IPA_MEM_V6_ROUTE_HASHED]); 487 488 ipa_table_init_add(trans, true, IPA_CMD_IP_V4_FILTER_INIT, 489 &ipa->mem[IPA_MEM_V4_FILTER], 490 &ipa->mem[IPA_MEM_V4_FILTER_HASHED]); 491 492 ipa_table_init_add(trans, true, IPA_CMD_IP_V6_FILTER_INIT, 493 &ipa->mem[IPA_MEM_V6_FILTER], 494 &ipa->mem[IPA_MEM_V6_FILTER_HASHED]); 495 496 gsi_trans_commit_wait(trans); 497 498 return 0; 499 } 500 501 void ipa_table_teardown(struct ipa *ipa) 502 { 503 /* Nothing to do */ /* XXX Maybe reset the tables? */ 504 } 505 506 /** 507 * ipa_filter_tuple_zero() - Zero an endpoint's hashed filter tuple 508 * @endpoint: Endpoint whose filter hash tuple should be zeroed 509 * 510 * Endpoint must be for the AP (not modem) and support filtering. Updates 511 * the filter hash values without changing route ones. 512 */ 513 static void ipa_filter_tuple_zero(struct ipa_endpoint *endpoint) 514 { 515 u32 endpoint_id = endpoint->endpoint_id; 516 u32 offset; 517 u32 val; 518 519 offset = IPA_REG_ENDP_FILTER_ROUTER_HSH_CFG_N_OFFSET(endpoint_id); 520 521 val = ioread32(endpoint->ipa->reg_virt + offset); 522 523 /* Zero all filter-related fields, preserving the rest */ 524 u32_replace_bits(val, 0, IPA_REG_ENDP_FILTER_HASH_MSK_ALL); 525 526 iowrite32(val, endpoint->ipa->reg_virt + offset); 527 } 528 529 static void ipa_filter_config(struct ipa *ipa, bool modem) 530 { 531 enum gsi_ee_id ee_id = modem ? GSI_EE_MODEM : GSI_EE_AP; 532 u32 ep_mask = ipa->filter_map; 533 534 /* IPA version 4.2 has no hashed route tables */ 535 if (ipa->version == IPA_VERSION_4_2) 536 return; 537 538 while (ep_mask) { 539 u32 endpoint_id = __ffs(ep_mask); 540 struct ipa_endpoint *endpoint; 541 542 ep_mask ^= BIT(endpoint_id); 543 544 endpoint = &ipa->endpoint[endpoint_id]; 545 if (endpoint->ee_id == ee_id) 546 ipa_filter_tuple_zero(endpoint); 547 } 548 } 549 550 static void ipa_filter_deconfig(struct ipa *ipa, bool modem) 551 { 552 /* Nothing to do */ 553 } 554 555 static bool ipa_route_id_modem(u32 route_id) 556 { 557 return route_id >= IPA_ROUTE_MODEM_MIN && 558 route_id <= IPA_ROUTE_MODEM_MIN + IPA_ROUTE_MODEM_COUNT - 1; 559 } 560 561 /** 562 * ipa_route_tuple_zero() - Zero a hashed route table entry tuple 563 * @ipa: IPA pointer 564 * @route_id: Route table entry whose hash tuple should be zeroed 565 * 566 * Updates the route hash values without changing filter ones. 567 */ 568 static void ipa_route_tuple_zero(struct ipa *ipa, u32 route_id) 569 { 570 u32 offset = IPA_REG_ENDP_FILTER_ROUTER_HSH_CFG_N_OFFSET(route_id); 571 u32 val; 572 573 val = ioread32(ipa->reg_virt + offset); 574 575 /* Zero all route-related fields, preserving the rest */ 576 u32_replace_bits(val, 0, IPA_REG_ENDP_ROUTER_HASH_MSK_ALL); 577 578 iowrite32(val, ipa->reg_virt + offset); 579 } 580 581 static void ipa_route_config(struct ipa *ipa, bool modem) 582 { 583 u32 route_id; 584 585 /* IPA version 4.2 has no hashed route tables */ 586 if (ipa->version == IPA_VERSION_4_2) 587 return; 588 589 for (route_id = 0; route_id < IPA_ROUTE_COUNT_MAX; route_id++) 590 if (ipa_route_id_modem(route_id) == modem) 591 ipa_route_tuple_zero(ipa, route_id); 592 } 593 594 static void ipa_route_deconfig(struct ipa *ipa, bool modem) 595 { 596 /* Nothing to do */ 597 } 598 599 void ipa_table_config(struct ipa *ipa) 600 { 601 ipa_filter_config(ipa, false); 602 ipa_filter_config(ipa, true); 603 ipa_route_config(ipa, false); 604 ipa_route_config(ipa, true); 605 } 606 607 void ipa_table_deconfig(struct ipa *ipa) 608 { 609 ipa_route_deconfig(ipa, true); 610 ipa_route_deconfig(ipa, false); 611 ipa_filter_deconfig(ipa, true); 612 ipa_filter_deconfig(ipa, false); 613 } 614 615 /* 616 * Initialize a coherent DMA allocation containing initialized filter and 617 * route table data. This is used when initializing or resetting the IPA 618 * filter or route table. 619 * 620 * The first entry in a filter table contains a bitmap indicating which 621 * endpoints contain entries in the table. In addition to that first entry, 622 * there are at most IPA_FILTER_COUNT_MAX entries that follow. Filter table 623 * entries are 64 bits wide, and (other than the bitmap) contain the DMA 624 * address of a filter rule. A "zero rule" indicates no filtering, and 625 * consists of 64 bits of zeroes. When a filter table is initialized (or 626 * reset) its entries are made to refer to the zero rule. 627 * 628 * Each entry in a route table is the DMA address of a routing rule. For 629 * routing there is also a 64-bit "zero rule" that means no routing, and 630 * when a route table is initialized or reset, its entries are made to refer 631 * to the zero rule. The zero rule is shared for route and filter tables. 632 * 633 * Note that the IPA hardware requires a filter or route rule address to be 634 * aligned on a 128 byte boundary. The coherent DMA buffer we allocate here 635 * has a minimum alignment, and we place the zero rule at the base of that 636 * allocated space. In ipa_table_init() we verify the minimum DMA allocation 637 * meets our requirement. 638 * 639 * +-------------------+ 640 * --> | zero rule | 641 * / |-------------------| 642 * | | filter mask | 643 * |\ |-------------------| 644 * | ---- zero rule address | \ 645 * |\ |-------------------| | 646 * | ---- zero rule address | | IPA_FILTER_COUNT_MAX 647 * | |-------------------| > or IPA_ROUTE_COUNT_MAX, 648 * | ... | whichever is greater 649 * \ |-------------------| | 650 * ---- zero rule address | / 651 * +-------------------+ 652 */ 653 int ipa_table_init(struct ipa *ipa) 654 { 655 u32 count = max_t(u32, IPA_FILTER_COUNT_MAX, IPA_ROUTE_COUNT_MAX); 656 struct device *dev = &ipa->pdev->dev; 657 dma_addr_t addr; 658 __le64 le_addr; 659 __le64 *virt; 660 size_t size; 661 662 ipa_table_validate_build(); 663 664 size = IPA_ZERO_RULE_SIZE + (1 + count) * IPA_TABLE_ENTRY_SIZE; 665 virt = dma_alloc_coherent(dev, size, &addr, GFP_KERNEL); 666 if (!virt) 667 return -ENOMEM; 668 669 ipa->table_virt = virt; 670 ipa->table_addr = addr; 671 672 /* First slot is the zero rule */ 673 *virt++ = 0; 674 675 /* Next is the filter table bitmap. The "soft" bitmap value 676 * must be converted to the hardware representation by shifting 677 * it left one position. (Bit 0 repesents global filtering, 678 * which is possible but not used.) 679 */ 680 *virt++ = cpu_to_le64((u64)ipa->filter_map << 1); 681 682 /* All the rest contain the DMA address of the zero rule */ 683 le_addr = cpu_to_le64(addr); 684 while (count--) 685 *virt++ = le_addr; 686 687 return 0; 688 } 689 690 void ipa_table_exit(struct ipa *ipa) 691 { 692 u32 count = max_t(u32, 1 + IPA_FILTER_COUNT_MAX, IPA_ROUTE_COUNT_MAX); 693 struct device *dev = &ipa->pdev->dev; 694 size_t size; 695 696 size = IPA_ZERO_RULE_SIZE + (1 + count) * IPA_TABLE_ENTRY_SIZE; 697 698 dma_free_coherent(dev, size, ipa->table_virt, ipa->table_addr); 699 ipa->table_addr = 0; 700 ipa->table_virt = NULL; 701 } 702