1 // SPDX-License-Identifier: GPL-2.0 2 3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved. 4 * Copyright (C) 2018-2022 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 (IPA-resident) memory that define 31 * filter and routing rules. An entry in either of these tables is a little 32 * endian 64-bit "slot" that holds the address of a rule definition. (The 33 * size of these slots is 64 bits regardless of the host DMA address size.) 34 * 35 * Separate tables (both filter and route) used for IPv4 and IPv6. There 36 * are normally another set of "hashed" filter and route tables, which are 37 * used with a hash of message metadata. Hashed operation is not supported 38 * by all IPA hardware (IPA v4.2 doesn't support hashed tables). 39 * 40 * Rules can be in local memory or in DRAM (system memory). The offset of 41 * an object (such as a route or filter table) in IPA-resident memory must 42 * 128-byte aligned. An object in system memory (such as a route or filter 43 * rule) must be at an 8-byte aligned address. We currently only place 44 * route or filter rules in system memory. 45 * 46 * A rule consists of a contiguous block of 32-bit values terminated with 47 * 32 zero bits. A special "zero entry" rule consisting of 64 zero bits 48 * represents "no filtering" or "no routing," and is the reset value for 49 * filter or route table rules. 50 * 51 * Each filter rule is associated with an AP or modem TX endpoint, though 52 * not all TX endpoints support filtering. The first 64-bit slot in a 53 * filter table is a bitmap indicating which endpoints have entries in 54 * the table. The low-order bit (bit 0) in this bitmap represents a 55 * special global filter, which applies to all traffic. This is not 56 * used in the current code. Bit 1, if set, indicates that there is an 57 * entry (i.e. slot containing a system address referring to a rule) for 58 * endpoint 0 in the table. Bit 3, if set, indicates there is an entry 59 * for endpoint 2, and so on. Space is set aside in IPA local memory to 60 * hold as many filter table entries as might be required, but typically 61 * they are not all used. 62 * 63 * The AP initializes all entries in a filter table to refer to a "zero" 64 * entry. Once initialized the modem and AP update the entries for 65 * endpoints they "own" directly. Currently the AP does not use the 66 * IPA filtering functionality. 67 * 68 * IPA Filter Table 69 * ---------------------- 70 * endpoint bitmap | 0x0000000000000048 | Bits 3 and 6 set (endpoints 2 and 5) 71 * |--------------------| 72 * 1st endpoint | 0x000123456789abc0 | DMA address for modem endpoint 2 rule 73 * |--------------------| 74 * 2nd endpoint | 0x000123456789abf0 | DMA address for AP endpoint 5 rule 75 * |--------------------| 76 * (unused) | | (Unused space in filter table) 77 * |--------------------| 78 * . . . 79 * |--------------------| 80 * (unused) | | (Unused space in filter table) 81 * ---------------------- 82 * 83 * The set of available route rules is divided about equally between the AP 84 * and modem. The AP initializes all entries in a route table to refer to 85 * a "zero entry". Once initialized, the modem and AP are responsible for 86 * updating their own entries. All entries in a route table are usable, 87 * though the AP currently does not use the IPA routing functionality. 88 * 89 * IPA Route Table 90 * ---------------------- 91 * 1st modem route | 0x0001234500001100 | DMA address for first route rule 92 * |--------------------| 93 * 2nd modem route | 0x0001234500001140 | DMA address for second route rule 94 * |--------------------| 95 * . . . 96 * |--------------------| 97 * Last modem route| 0x0001234500002280 | DMA address for Nth route rule 98 * |--------------------| 99 * 1st AP route | 0x0001234500001100 | DMA address for route rule (N+1) 100 * |--------------------| 101 * 2nd AP route | 0x0001234500001140 | DMA address for next route rule 102 * |--------------------| 103 * . . . 104 * |--------------------| 105 * Last AP route | 0x0001234500002280 | DMA address for last route rule 106 * ---------------------- 107 */ 108 109 /* Assignment of route table entries to the modem and AP */ 110 #define IPA_ROUTE_MODEM_MIN 0 111 #define IPA_ROUTE_AP_MIN IPA_ROUTE_MODEM_COUNT 112 #define IPA_ROUTE_AP_COUNT \ 113 (IPA_ROUTE_COUNT_MAX - IPA_ROUTE_MODEM_COUNT) 114 115 /* Filter or route rules consist of a set of 32-bit values followed by a 116 * 32-bit all-zero rule list terminator. The "zero rule" is simply an 117 * all-zero rule followed by the list terminator. 118 */ 119 #define IPA_ZERO_RULE_SIZE (2 * sizeof(__le32)) 120 121 /* Check things that can be validated at build time. */ 122 static void ipa_table_validate_build(void) 123 { 124 /* Filter and route tables contain DMA addresses that refer 125 * to filter or route rules. But the size of a table entry 126 * is 64 bits regardless of what the size of an AP DMA address 127 * is. A fixed constant defines the size of an entry, and 128 * code in ipa_table_init() uses a pointer to __le64 to 129 * initialize tables. 130 */ 131 BUILD_BUG_ON(sizeof(dma_addr_t) > sizeof(__le64)); 132 133 /* A "zero rule" is used to represent no filtering or no routing. 134 * It is a 64-bit block of zeroed memory. Code in ipa_table_init() 135 * assumes that it can be written using a pointer to __le64. 136 */ 137 BUILD_BUG_ON(IPA_ZERO_RULE_SIZE != sizeof(__le64)); 138 139 /* Impose a practical limit on the number of routes */ 140 BUILD_BUG_ON(IPA_ROUTE_COUNT_MAX > 32); 141 /* The modem must be allotted at least one route table entry */ 142 BUILD_BUG_ON(!IPA_ROUTE_MODEM_COUNT); 143 /* But it can't have more than what is available */ 144 BUILD_BUG_ON(IPA_ROUTE_MODEM_COUNT > IPA_ROUTE_COUNT_MAX); 145 146 } 147 148 static bool 149 ipa_table_valid_one(struct ipa *ipa, enum ipa_mem_id mem_id, bool route) 150 { 151 const struct ipa_mem *mem = ipa_mem_find(ipa, mem_id); 152 struct device *dev = &ipa->pdev->dev; 153 u32 size; 154 155 if (route) 156 size = IPA_ROUTE_COUNT_MAX * sizeof(__le64); 157 else 158 size = (1 + IPA_FILTER_COUNT_MAX) * sizeof(__le64); 159 160 if (!ipa_cmd_table_valid(ipa, mem, route)) 161 return false; 162 163 /* mem->size >= size is sufficient, but we'll demand more */ 164 if (mem->size == size) 165 return true; 166 167 /* Hashed table regions can be zero size if hashing is not supported */ 168 if (ipa_table_hash_support(ipa) && !mem->size) 169 return true; 170 171 dev_err(dev, "%s table region %u size 0x%02x, expected 0x%02x\n", 172 route ? "route" : "filter", mem_id, mem->size, size); 173 174 return false; 175 } 176 177 /* Verify the filter and route table memory regions are the expected size */ 178 bool ipa_table_valid(struct ipa *ipa) 179 { 180 bool valid; 181 182 valid = ipa_table_valid_one(ipa, IPA_MEM_V4_FILTER, false); 183 valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V6_FILTER, false); 184 valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V4_ROUTE, true); 185 valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V6_ROUTE, true); 186 187 if (!ipa_table_hash_support(ipa)) 188 return valid; 189 190 valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V4_FILTER_HASHED, 191 false); 192 valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V6_FILTER_HASHED, 193 false); 194 valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V4_ROUTE_HASHED, 195 true); 196 valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V6_ROUTE_HASHED, 197 true); 198 199 return valid; 200 } 201 202 bool ipa_filter_map_valid(struct ipa *ipa, u32 filter_map) 203 { 204 struct device *dev = &ipa->pdev->dev; 205 u32 count; 206 207 if (!filter_map) { 208 dev_err(dev, "at least one filtering endpoint is required\n"); 209 210 return false; 211 } 212 213 count = hweight32(filter_map); 214 if (count > IPA_FILTER_COUNT_MAX) { 215 dev_err(dev, "too many filtering endpoints (%u, max %u)\n", 216 count, IPA_FILTER_COUNT_MAX); 217 218 return false; 219 } 220 221 return true; 222 } 223 224 /* Zero entry count means no table, so just return a 0 address */ 225 static dma_addr_t ipa_table_addr(struct ipa *ipa, bool filter_mask, u16 count) 226 { 227 u32 skip; 228 229 if (!count) 230 return 0; 231 232 WARN_ON(count > max_t(u32, IPA_FILTER_COUNT_MAX, IPA_ROUTE_COUNT_MAX)); 233 234 /* Skip over the zero rule and possibly the filter mask */ 235 skip = filter_mask ? 1 : 2; 236 237 return ipa->table_addr + skip * sizeof(*ipa->table_virt); 238 } 239 240 static void ipa_table_reset_add(struct gsi_trans *trans, bool filter, 241 u16 first, u16 count, enum ipa_mem_id mem_id) 242 { 243 struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi); 244 const struct ipa_mem *mem = ipa_mem_find(ipa, mem_id); 245 dma_addr_t addr; 246 u32 offset; 247 u16 size; 248 249 /* Nothing to do if the table memory region is empty */ 250 if (!mem->size) 251 return; 252 253 if (filter) 254 first++; /* skip over bitmap */ 255 256 offset = mem->offset + first * sizeof(__le64); 257 size = count * sizeof(__le64); 258 addr = ipa_table_addr(ipa, false, count); 259 260 ipa_cmd_dma_shared_mem_add(trans, offset, size, addr, true); 261 } 262 263 /* Reset entries in a single filter table belonging to either the AP or 264 * modem to refer to the zero entry. The memory region supplied will be 265 * for the IPv4 and IPv6 non-hashed and hashed filter tables. 266 */ 267 static int 268 ipa_filter_reset_table(struct ipa *ipa, enum ipa_mem_id mem_id, bool modem) 269 { 270 u32 ep_mask = ipa->filter_map; 271 u32 count = hweight32(ep_mask); 272 struct gsi_trans *trans; 273 enum gsi_ee_id ee_id; 274 275 trans = ipa_cmd_trans_alloc(ipa, count); 276 if (!trans) { 277 dev_err(&ipa->pdev->dev, 278 "no transaction for %s filter reset\n", 279 modem ? "modem" : "AP"); 280 return -EBUSY; 281 } 282 283 ee_id = modem ? GSI_EE_MODEM : GSI_EE_AP; 284 while (ep_mask) { 285 u32 endpoint_id = __ffs(ep_mask); 286 struct ipa_endpoint *endpoint; 287 288 ep_mask ^= BIT(endpoint_id); 289 290 endpoint = &ipa->endpoint[endpoint_id]; 291 if (endpoint->ee_id != ee_id) 292 continue; 293 294 ipa_table_reset_add(trans, true, endpoint_id, 1, mem_id); 295 } 296 297 gsi_trans_commit_wait(trans); 298 299 return 0; 300 } 301 302 /* Theoretically, each filter table could have more filter slots to 303 * update than the maximum number of commands in a transaction. So 304 * we do each table separately. 305 */ 306 static int ipa_filter_reset(struct ipa *ipa, bool modem) 307 { 308 int ret; 309 310 ret = ipa_filter_reset_table(ipa, IPA_MEM_V4_FILTER, modem); 311 if (ret) 312 return ret; 313 314 ret = ipa_filter_reset_table(ipa, IPA_MEM_V4_FILTER_HASHED, modem); 315 if (ret) 316 return ret; 317 318 ret = ipa_filter_reset_table(ipa, IPA_MEM_V6_FILTER, modem); 319 if (ret) 320 return ret; 321 ret = ipa_filter_reset_table(ipa, IPA_MEM_V6_FILTER_HASHED, modem); 322 323 return ret; 324 } 325 326 /* The AP routes and modem routes are each contiguous within the 327 * table. We can update each table with a single command, and we 328 * won't exceed the per-transaction command limit. 329 * */ 330 static int ipa_route_reset(struct ipa *ipa, bool modem) 331 { 332 struct gsi_trans *trans; 333 u16 first; 334 u16 count; 335 336 trans = ipa_cmd_trans_alloc(ipa, 4); 337 if (!trans) { 338 dev_err(&ipa->pdev->dev, 339 "no transaction for %s route reset\n", 340 modem ? "modem" : "AP"); 341 return -EBUSY; 342 } 343 344 if (modem) { 345 first = IPA_ROUTE_MODEM_MIN; 346 count = IPA_ROUTE_MODEM_COUNT; 347 } else { 348 first = IPA_ROUTE_AP_MIN; 349 count = IPA_ROUTE_AP_COUNT; 350 } 351 352 ipa_table_reset_add(trans, false, first, count, IPA_MEM_V4_ROUTE); 353 ipa_table_reset_add(trans, false, first, count, 354 IPA_MEM_V4_ROUTE_HASHED); 355 356 ipa_table_reset_add(trans, false, first, count, IPA_MEM_V6_ROUTE); 357 ipa_table_reset_add(trans, false, first, count, 358 IPA_MEM_V6_ROUTE_HASHED); 359 360 gsi_trans_commit_wait(trans); 361 362 return 0; 363 } 364 365 void ipa_table_reset(struct ipa *ipa, bool modem) 366 { 367 struct device *dev = &ipa->pdev->dev; 368 const char *ee_name; 369 int ret; 370 371 ee_name = modem ? "modem" : "AP"; 372 373 /* Report errors, but reset filter and route tables */ 374 ret = ipa_filter_reset(ipa, modem); 375 if (ret) 376 dev_err(dev, "error %d resetting filter table for %s\n", 377 ret, ee_name); 378 379 ret = ipa_route_reset(ipa, modem); 380 if (ret) 381 dev_err(dev, "error %d resetting route table for %s\n", 382 ret, ee_name); 383 } 384 385 int ipa_table_hash_flush(struct ipa *ipa) 386 { 387 const struct ipa_reg *reg; 388 struct gsi_trans *trans; 389 u32 offset; 390 u32 val; 391 392 if (!ipa_table_hash_support(ipa)) 393 return 0; 394 395 trans = ipa_cmd_trans_alloc(ipa, 1); 396 if (!trans) { 397 dev_err(&ipa->pdev->dev, "no transaction for hash flush\n"); 398 return -EBUSY; 399 } 400 401 reg = ipa_reg(ipa, FILT_ROUT_HASH_FLUSH); 402 offset = ipa_reg_offset(reg); 403 404 val = ipa_reg_bit(reg, IPV6_ROUTER_HASH); 405 val |= ipa_reg_bit(reg, IPV6_FILTER_HASH); 406 val |= ipa_reg_bit(reg, IPV4_ROUTER_HASH); 407 val |= ipa_reg_bit(reg, IPV4_FILTER_HASH); 408 409 ipa_cmd_register_write_add(trans, offset, val, val, false); 410 411 gsi_trans_commit_wait(trans); 412 413 return 0; 414 } 415 416 static void ipa_table_init_add(struct gsi_trans *trans, bool filter, 417 enum ipa_cmd_opcode opcode, 418 enum ipa_mem_id mem_id, 419 enum ipa_mem_id hash_mem_id) 420 { 421 struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi); 422 const struct ipa_mem *hash_mem = ipa_mem_find(ipa, hash_mem_id); 423 const struct ipa_mem *mem = ipa_mem_find(ipa, mem_id); 424 dma_addr_t hash_addr; 425 dma_addr_t addr; 426 u32 zero_offset; 427 u16 hash_count; 428 u32 zero_size; 429 u16 hash_size; 430 u16 count; 431 u16 size; 432 433 /* Compute the number of table entries to initialize */ 434 if (filter) { 435 /* The number of filtering endpoints determines number of 436 * entries in the filter table; we also add one more "slot" 437 * to hold the bitmap itself. The size of the hashed filter 438 * table is either the same as the non-hashed one, or zero. 439 */ 440 count = 1 + hweight32(ipa->filter_map); 441 hash_count = hash_mem->size ? count : 0; 442 } else { 443 /* The size of a route table region determines the number 444 * of entries it has. 445 */ 446 count = mem->size / sizeof(__le64); 447 hash_count = hash_mem->size / sizeof(__le64); 448 } 449 size = count * sizeof(__le64); 450 hash_size = hash_count * sizeof(__le64); 451 452 addr = ipa_table_addr(ipa, filter, count); 453 hash_addr = ipa_table_addr(ipa, filter, hash_count); 454 455 ipa_cmd_table_init_add(trans, opcode, size, mem->offset, addr, 456 hash_size, hash_mem->offset, hash_addr); 457 if (!filter) 458 return; 459 460 /* Zero the unused space in the filter table */ 461 zero_offset = mem->offset + size; 462 zero_size = mem->size - size; 463 ipa_cmd_dma_shared_mem_add(trans, zero_offset, zero_size, 464 ipa->zero_addr, true); 465 if (!hash_size) 466 return; 467 468 /* Zero the unused space in the hashed filter table */ 469 zero_offset = hash_mem->offset + hash_size; 470 zero_size = hash_mem->size - hash_size; 471 ipa_cmd_dma_shared_mem_add(trans, zero_offset, zero_size, 472 ipa->zero_addr, true); 473 } 474 475 int ipa_table_setup(struct ipa *ipa) 476 { 477 struct gsi_trans *trans; 478 479 /* We will need at most 8 TREs: 480 * - IPv4: 481 * - One for route table initialization (non-hashed and hashed) 482 * - One for filter table initialization (non-hashed and hashed) 483 * - One to zero unused entries in the non-hashed filter table 484 * - One to zero unused entries in the hashed filter table 485 * - IPv6: 486 * - One for route table initialization (non-hashed and hashed) 487 * - One for filter table initialization (non-hashed and hashed) 488 * - One to zero unused entries in the non-hashed filter table 489 * - One to zero unused entries in the hashed filter table 490 * All platforms support at least 8 TREs in a transaction. 491 */ 492 trans = ipa_cmd_trans_alloc(ipa, 8); 493 if (!trans) { 494 dev_err(&ipa->pdev->dev, "no transaction for table setup\n"); 495 return -EBUSY; 496 } 497 498 ipa_table_init_add(trans, false, IPA_CMD_IP_V4_ROUTING_INIT, 499 IPA_MEM_V4_ROUTE, IPA_MEM_V4_ROUTE_HASHED); 500 501 ipa_table_init_add(trans, false, IPA_CMD_IP_V6_ROUTING_INIT, 502 IPA_MEM_V6_ROUTE, IPA_MEM_V6_ROUTE_HASHED); 503 504 ipa_table_init_add(trans, true, IPA_CMD_IP_V4_FILTER_INIT, 505 IPA_MEM_V4_FILTER, IPA_MEM_V4_FILTER_HASHED); 506 507 ipa_table_init_add(trans, true, IPA_CMD_IP_V6_FILTER_INIT, 508 IPA_MEM_V6_FILTER, IPA_MEM_V6_FILTER_HASHED); 509 510 gsi_trans_commit_wait(trans); 511 512 return 0; 513 } 514 515 /** 516 * ipa_filter_tuple_zero() - Zero an endpoint's hashed filter tuple 517 * @endpoint: Endpoint whose filter hash tuple should be zeroed 518 * 519 * Endpoint must be for the AP (not modem) and support filtering. Updates 520 * the filter hash values without changing route ones. 521 */ 522 static void ipa_filter_tuple_zero(struct ipa_endpoint *endpoint) 523 { 524 u32 endpoint_id = endpoint->endpoint_id; 525 struct ipa *ipa = endpoint->ipa; 526 const struct ipa_reg *reg; 527 u32 offset; 528 u32 val; 529 530 reg = ipa_reg(ipa, ENDP_FILTER_ROUTER_HSH_CFG); 531 532 offset = ipa_reg_n_offset(reg, endpoint_id); 533 val = ioread32(endpoint->ipa->reg_virt + offset); 534 535 /* Zero all filter-related fields, preserving the rest */ 536 val &= ~ipa_reg_fmask(reg, FILTER_HASH_MSK_ALL); 537 538 iowrite32(val, endpoint->ipa->reg_virt + offset); 539 } 540 541 /* Configure a hashed filter table; there is no ipa_filter_deconfig() */ 542 static void ipa_filter_config(struct ipa *ipa, bool modem) 543 { 544 enum gsi_ee_id ee_id = modem ? GSI_EE_MODEM : GSI_EE_AP; 545 u32 ep_mask = ipa->filter_map; 546 547 if (!ipa_table_hash_support(ipa)) 548 return; 549 550 while (ep_mask) { 551 u32 endpoint_id = __ffs(ep_mask); 552 struct ipa_endpoint *endpoint; 553 554 ep_mask ^= BIT(endpoint_id); 555 556 endpoint = &ipa->endpoint[endpoint_id]; 557 if (endpoint->ee_id == ee_id) 558 ipa_filter_tuple_zero(endpoint); 559 } 560 } 561 562 static bool ipa_route_id_modem(u32 route_id) 563 { 564 return route_id >= IPA_ROUTE_MODEM_MIN && 565 route_id <= IPA_ROUTE_MODEM_MIN + IPA_ROUTE_MODEM_COUNT - 1; 566 } 567 568 /** 569 * ipa_route_tuple_zero() - Zero a hashed route table entry tuple 570 * @ipa: IPA pointer 571 * @route_id: Route table entry whose hash tuple should be zeroed 572 * 573 * Updates the route hash values without changing filter ones. 574 */ 575 static void ipa_route_tuple_zero(struct ipa *ipa, u32 route_id) 576 { 577 const struct ipa_reg *reg; 578 u32 offset; 579 u32 val; 580 581 reg = ipa_reg(ipa, ENDP_FILTER_ROUTER_HSH_CFG); 582 offset = ipa_reg_n_offset(reg, route_id); 583 584 val = ioread32(ipa->reg_virt + offset); 585 586 /* Zero all route-related fields, preserving the rest */ 587 val &= ~ipa_reg_fmask(reg, ROUTER_HASH_MSK_ALL); 588 589 iowrite32(val, ipa->reg_virt + offset); 590 } 591 592 /* Configure a hashed route table; there is no ipa_route_deconfig() */ 593 static void ipa_route_config(struct ipa *ipa, bool modem) 594 { 595 u32 route_id; 596 597 if (!ipa_table_hash_support(ipa)) 598 return; 599 600 for (route_id = 0; route_id < IPA_ROUTE_COUNT_MAX; route_id++) 601 if (ipa_route_id_modem(route_id) == modem) 602 ipa_route_tuple_zero(ipa, route_id); 603 } 604 605 /* Configure a filter and route tables; there is no ipa_table_deconfig() */ 606 void ipa_table_config(struct ipa *ipa) 607 { 608 ipa_filter_config(ipa, false); 609 ipa_filter_config(ipa, true); 610 ipa_route_config(ipa, false); 611 ipa_route_config(ipa, true); 612 } 613 614 /* 615 * Initialize a coherent DMA allocation containing initialized filter and 616 * route table data. This is used when initializing or resetting the IPA 617 * filter or route table. 618 * 619 * The first entry in a filter table contains a bitmap indicating which 620 * endpoints contain entries in the table. In addition to that first entry, 621 * there are at most IPA_FILTER_COUNT_MAX entries that follow. Filter table 622 * entries are 64 bits wide, and (other than the bitmap) contain the DMA 623 * address of a filter rule. A "zero rule" indicates no filtering, and 624 * consists of 64 bits of zeroes. When a filter table is initialized (or 625 * reset) its entries are made to refer to the zero rule. 626 * 627 * Each entry in a route table is the DMA address of a routing rule. For 628 * routing there is also a 64-bit "zero rule" that means no routing, and 629 * when a route table is initialized or reset, its entries are made to refer 630 * to the zero rule. The zero rule is shared for route and filter tables. 631 * 632 * Note that the IPA hardware requires a filter or route rule address to be 633 * aligned on a 128 byte boundary. The coherent DMA buffer we allocate here 634 * has a minimum alignment, and we place the zero rule at the base of that 635 * allocated space. In ipa_table_init() we verify the minimum DMA allocation 636 * meets our requirement. 637 * 638 * +-------------------+ 639 * --> | zero rule | 640 * / |-------------------| 641 * | | filter mask | 642 * |\ |-------------------| 643 * | ---- zero rule address | \ 644 * |\ |-------------------| | 645 * | ---- zero rule address | | IPA_FILTER_COUNT_MAX 646 * | |-------------------| > or IPA_ROUTE_COUNT_MAX, 647 * | ... | whichever is greater 648 * \ |-------------------| | 649 * ---- zero rule address | / 650 * +-------------------+ 651 */ 652 int ipa_table_init(struct ipa *ipa) 653 { 654 u32 count = max_t(u32, IPA_FILTER_COUNT_MAX, IPA_ROUTE_COUNT_MAX); 655 struct device *dev = &ipa->pdev->dev; 656 dma_addr_t addr; 657 __le64 le_addr; 658 __le64 *virt; 659 size_t size; 660 661 ipa_table_validate_build(); 662 663 /* The IPA hardware requires route and filter table rules to be 664 * aligned on a 128-byte boundary. We put the "zero rule" at the 665 * base of the table area allocated here. The DMA address returned 666 * by dma_alloc_coherent() is guaranteed to be a power-of-2 number 667 * of pages, which satisfies the rule alignment requirement. 668 */ 669 size = IPA_ZERO_RULE_SIZE + (1 + count) * sizeof(__le64); 670 virt = dma_alloc_coherent(dev, size, &addr, GFP_KERNEL); 671 if (!virt) 672 return -ENOMEM; 673 674 ipa->table_virt = virt; 675 ipa->table_addr = addr; 676 677 /* First slot is the zero rule */ 678 *virt++ = 0; 679 680 /* Next is the filter table bitmap. The "soft" bitmap value 681 * must be converted to the hardware representation by shifting 682 * it left one position. (Bit 0 repesents global filtering, 683 * which is possible but not used.) 684 */ 685 *virt++ = cpu_to_le64((u64)ipa->filter_map << 1); 686 687 /* All the rest contain the DMA address of the zero rule */ 688 le_addr = cpu_to_le64(addr); 689 while (count--) 690 *virt++ = le_addr; 691 692 return 0; 693 } 694 695 void ipa_table_exit(struct ipa *ipa) 696 { 697 u32 count = max_t(u32, 1 + IPA_FILTER_COUNT_MAX, IPA_ROUTE_COUNT_MAX); 698 struct device *dev = &ipa->pdev->dev; 699 size_t size; 700 701 size = IPA_ZERO_RULE_SIZE + (1 + count) * sizeof(__le64); 702 703 dma_free_coherent(dev, size, ipa->table_virt, ipa->table_addr); 704 ipa->table_addr = 0; 705 ipa->table_virt = NULL; 706 } 707