1/* 2 * Copyright 2010 Tilera Corporation. All Rights Reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation, version 2. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or 11 * NON INFRINGEMENT. See the GNU General Public License for 12 * more details. 13 */ 14 15/** 16 * @file drv_xgbe_intf.h 17 * Interface to the hypervisor XGBE driver. 18 */ 19 20#ifndef __DRV_XGBE_INTF_H__ 21#define __DRV_XGBE_INTF_H__ 22 23/** 24 * An object for forwarding VAs and PAs to the hypervisor. 25 * @ingroup types 26 * 27 * This allows the supervisor to specify a number of areas of memory to 28 * store packet buffers. 29 */ 30typedef struct 31{ 32 /** The physical address of the memory. */ 33 HV_PhysAddr pa; 34 /** Page table entry for the memory. This is only used to derive the 35 * memory's caching mode; the PA bits are ignored. */ 36 HV_PTE pte; 37 /** The virtual address of the memory. */ 38 HV_VirtAddr va; 39 /** Size (in bytes) of the memory area. */ 40 int size; 41 42} 43netio_ipp_address_t; 44 45/** The various pread/pwrite offsets into the hypervisor-level driver. 46 * @ingroup types 47 */ 48typedef enum 49{ 50 /** Inform the Linux driver of the address of the NetIO arena memory. 51 * This offset is actually only used to convey information from netio 52 * to the Linux driver; it never makes it from there to the hypervisor. 53 * Write-only; takes a uint32_t specifying the VA address. */ 54 NETIO_FIXED_ADDR = 0x5000000000000000ULL, 55 56 /** Inform the Linux driver of the size of the NetIO arena memory. 57 * This offset is actually only used to convey information from netio 58 * to the Linux driver; it never makes it from there to the hypervisor. 59 * Write-only; takes a uint32_t specifying the VA size. */ 60 NETIO_FIXED_SIZE = 0x5100000000000000ULL, 61 62 /** Register current tile with IPP. Write then read: write, takes a 63 * netio_input_config_t, read returns a pointer to a netio_queue_impl_t. */ 64 NETIO_IPP_INPUT_REGISTER_OFF = 0x6000000000000000ULL, 65 66 /** Unregister current tile from IPP. Write-only, takes a dummy argument. */ 67 NETIO_IPP_INPUT_UNREGISTER_OFF = 0x6100000000000000ULL, 68 69 /** Start packets flowing. Write-only, takes a dummy argument. */ 70 NETIO_IPP_INPUT_INIT_OFF = 0x6200000000000000ULL, 71 72 /** Stop packets flowing. Write-only, takes a dummy argument. */ 73 NETIO_IPP_INPUT_UNINIT_OFF = 0x6300000000000000ULL, 74 75 /** Configure group (typically we group on VLAN). Write-only: takes an 76 * array of netio_group_t's, low 24 bits of the offset is the base group 77 * number times the size of a netio_group_t. */ 78 NETIO_IPP_INPUT_GROUP_CFG_OFF = 0x6400000000000000ULL, 79 80 /** Configure bucket. Write-only: takes an array of netio_bucket_t's, low 81 * 24 bits of the offset is the base bucket number times the size of a 82 * netio_bucket_t. */ 83 NETIO_IPP_INPUT_BUCKET_CFG_OFF = 0x6500000000000000ULL, 84 85 /** Get/set a parameter. Read or write: read or write data is the parameter 86 * value, low 32 bits of the offset is a __netio_getset_offset_t. */ 87 NETIO_IPP_PARAM_OFF = 0x6600000000000000ULL, 88 89 /** Get fast I/O index. Read-only; returns a 4-byte base index value. */ 90 NETIO_IPP_GET_FASTIO_OFF = 0x6700000000000000ULL, 91 92 /** Configure hijack IP address. Packets with this IPv4 dest address 93 * go to bucket NETIO_NUM_BUCKETS - 1. Write-only: takes an IP address 94 * in some standard form. FIXME: Define the form! */ 95 NETIO_IPP_INPUT_HIJACK_CFG_OFF = 0x6800000000000000ULL, 96 97 /** 98 * Offsets beyond this point are reserved for the supervisor (although that 99 * enforcement must be done by the supervisor driver itself). 100 */ 101 NETIO_IPP_USER_MAX_OFF = 0x6FFFFFFFFFFFFFFFULL, 102 103 /** Register I/O memory. Write-only, takes a netio_ipp_address_t. */ 104 NETIO_IPP_IOMEM_REGISTER_OFF = 0x7000000000000000ULL, 105 106 /** Unregister I/O memory. Write-only, takes a netio_ipp_address_t. */ 107 NETIO_IPP_IOMEM_UNREGISTER_OFF = 0x7100000000000000ULL, 108 109 /* Offsets greater than 0x7FFFFFFF can't be used directly from Linux 110 * userspace code due to limitations in the pread/pwrite syscalls. */ 111 112 /** Drain LIPP buffers. */ 113 NETIO_IPP_DRAIN_OFF = 0xFA00000000000000ULL, 114 115 /** Supply a netio_ipp_address_t to be used as shared memory for the 116 * LEPP command queue. */ 117 NETIO_EPP_SHM_OFF = 0xFB00000000000000ULL, 118 119 /* 0xFC... is currently unused. */ 120 121 /** Stop IPP/EPP tiles. Write-only, takes a dummy argument. */ 122 NETIO_IPP_STOP_SHIM_OFF = 0xFD00000000000000ULL, 123 124 /** Start IPP/EPP tiles. Write-only, takes a dummy argument. */ 125 NETIO_IPP_START_SHIM_OFF = 0xFE00000000000000ULL, 126 127 /** Supply packet arena. Write-only, takes an array of 128 * netio_ipp_address_t values. */ 129 NETIO_IPP_ADDRESS_OFF = 0xFF00000000000000ULL, 130} netio_hv_offset_t; 131 132/** Extract the base offset from an offset */ 133#define NETIO_BASE_OFFSET(off) ((off) & 0xFF00000000000000ULL) 134/** Extract the local offset from an offset */ 135#define NETIO_LOCAL_OFFSET(off) ((off) & 0x00FFFFFFFFFFFFFFULL) 136 137 138/** 139 * Get/set offset. 140 */ 141typedef union 142{ 143 struct 144 { 145 uint64_t addr:48; /**< Class-specific address */ 146 unsigned int class:8; /**< Class (e.g., NETIO_PARAM) */ 147 unsigned int opcode:8; /**< High 8 bits of NETIO_IPP_PARAM_OFF */ 148 } 149 bits; /**< Bitfields */ 150 uint64_t word; /**< Aggregated value to use as the offset */ 151} 152__netio_getset_offset_t; 153 154/** 155 * Fast I/O index offsets (must be contiguous). 156 */ 157typedef enum 158{ 159 NETIO_FASTIO_ALLOCATE = 0, /**< Get empty packet buffer */ 160 NETIO_FASTIO_FREE_BUFFER = 1, /**< Give buffer back to IPP */ 161 NETIO_FASTIO_RETURN_CREDITS = 2, /**< Give credits to IPP */ 162 NETIO_FASTIO_SEND_PKT_NOCK = 3, /**< Send a packet, no checksum */ 163 NETIO_FASTIO_SEND_PKT_CK = 4, /**< Send a packet, with checksum */ 164 NETIO_FASTIO_SEND_PKT_VEC = 5, /**< Send a vector of packets */ 165 NETIO_FASTIO_SENDV_PKT = 6, /**< Sendv one packet */ 166 NETIO_FASTIO_NUM_INDEX = 7, /**< Total number of fast I/O indices */ 167} netio_fastio_index_t; 168 169/** 3-word return type for Fast I/O call. */ 170typedef struct 171{ 172 int err; /**< Error code. */ 173 uint32_t val0; /**< Value. Meaning depends upon the specific call. */ 174 uint32_t val1; /**< Value. Meaning depends upon the specific call. */ 175} netio_fastio_rv3_t; 176 177/** 0-argument fast I/O call */ 178int __netio_fastio0(uint32_t fastio_index); 179/** 1-argument fast I/O call */ 180int __netio_fastio1(uint32_t fastio_index, uint32_t arg0); 181/** 3-argument fast I/O call, 2-word return value */ 182netio_fastio_rv3_t __netio_fastio3_rv3(uint32_t fastio_index, uint32_t arg0, 183 uint32_t arg1, uint32_t arg2); 184/** 4-argument fast I/O call */ 185int __netio_fastio4(uint32_t fastio_index, uint32_t arg0, uint32_t arg1, 186 uint32_t arg2, uint32_t arg3); 187/** 6-argument fast I/O call */ 188int __netio_fastio6(uint32_t fastio_index, uint32_t arg0, uint32_t arg1, 189 uint32_t arg2, uint32_t arg3, uint32_t arg4, uint32_t arg5); 190/** 9-argument fast I/O call */ 191int __netio_fastio9(uint32_t fastio_index, uint32_t arg0, uint32_t arg1, 192 uint32_t arg2, uint32_t arg3, uint32_t arg4, uint32_t arg5, 193 uint32_t arg6, uint32_t arg7, uint32_t arg8); 194 195/** Allocate an empty packet. 196 * @param fastio_index Fast I/O index. 197 * @param size Size of the packet to allocate. 198 */ 199#define __netio_fastio_allocate(fastio_index, size) \ 200 __netio_fastio1((fastio_index) + NETIO_FASTIO_ALLOCATE, size) 201 202/** Free a buffer. 203 * @param fastio_index Fast I/O index. 204 * @param handle Handle for the packet to free. 205 */ 206#define __netio_fastio_free_buffer(fastio_index, handle) \ 207 __netio_fastio1((fastio_index) + NETIO_FASTIO_FREE_BUFFER, handle) 208 209/** Increment our receive credits. 210 * @param fastio_index Fast I/O index. 211 * @param credits Number of credits to add. 212 */ 213#define __netio_fastio_return_credits(fastio_index, credits) \ 214 __netio_fastio1((fastio_index) + NETIO_FASTIO_RETURN_CREDITS, credits) 215 216/** Send packet, no checksum. 217 * @param fastio_index Fast I/O index. 218 * @param ackflag Nonzero if we want an ack. 219 * @param size Size of the packet. 220 * @param va Virtual address of start of packet. 221 * @param handle Packet handle. 222 */ 223#define __netio_fastio_send_pkt_nock(fastio_index, ackflag, size, va, handle) \ 224 __netio_fastio4((fastio_index) + NETIO_FASTIO_SEND_PKT_NOCK, ackflag, \ 225 size, va, handle) 226 227/** Send packet, calculate checksum. 228 * @param fastio_index Fast I/O index. 229 * @param ackflag Nonzero if we want an ack. 230 * @param size Size of the packet. 231 * @param va Virtual address of start of packet. 232 * @param handle Packet handle. 233 * @param csum0 Shim checksum header. 234 * @param csum1 Checksum seed. 235 */ 236#define __netio_fastio_send_pkt_ck(fastio_index, ackflag, size, va, handle, \ 237 csum0, csum1) \ 238 __netio_fastio6((fastio_index) + NETIO_FASTIO_SEND_PKT_CK, ackflag, \ 239 size, va, handle, csum0, csum1) 240 241 242/** Format for the "csum0" argument to the __netio_fastio_send routines 243 * and LEPP. Note that this is currently exactly identical to the 244 * ShimProtocolOffloadHeader. 245 */ 246typedef union 247{ 248 struct 249 { 250 unsigned int start_byte:7; /**< The first byte to be checksummed */ 251 unsigned int count:14; /**< Number of bytes to be checksummed. */ 252 unsigned int destination_byte:7; /**< The byte to write the checksum to. */ 253 unsigned int reserved:4; /**< Reserved. */ 254 } bits; /**< Decomposed method of access. */ 255 unsigned int word; /**< To send out the IDN. */ 256} __netio_checksum_header_t; 257 258 259/** Sendv packet with 1 or 2 segments. 260 * @param fastio_index Fast I/O index. 261 * @param flags Ack/csum/notify flags in low 3 bits; number of segments minus 262 * 1 in next 2 bits; expected checksum in high 16 bits. 263 * @param confno Confirmation number to request, if notify flag set. 264 * @param csum0 Checksum descriptor; if zero, no checksum. 265 * @param va_F Virtual address of first segment. 266 * @param va_L Virtual address of last segment, if 2 segments. 267 * @param len_F_L Length of first segment in low 16 bits; length of last 268 * segment, if 2 segments, in high 16 bits. 269 */ 270#define __netio_fastio_sendv_pkt_1_2(fastio_index, flags, confno, csum0, \ 271 va_F, va_L, len_F_L) \ 272 __netio_fastio6((fastio_index) + NETIO_FASTIO_SENDV_PKT, flags, confno, \ 273 csum0, va_F, va_L, len_F_L) 274 275/** Send packet on PCIe interface. 276 * @param fastio_index Fast I/O index. 277 * @param flags Ack/csum/notify flags in low 3 bits. 278 * @param confno Confirmation number to request, if notify flag set. 279 * @param csum0 Checksum descriptor; Hard wired 0, not needed for PCIe. 280 * @param va_F Virtual address of the packet buffer. 281 * @param va_L Virtual address of last segment, if 2 segments. Hard wired 0. 282 * @param len_F_L Length of the packet buffer in low 16 bits. 283 */ 284#define __netio_fastio_send_pcie_pkt(fastio_index, flags, confno, csum0, \ 285 va_F, va_L, len_F_L) \ 286 __netio_fastio6((fastio_index) + PCIE_FASTIO_SENDV_PKT, flags, confno, \ 287 csum0, va_F, va_L, len_F_L) 288 289/** Sendv packet with 3 or 4 segments. 290 * @param fastio_index Fast I/O index. 291 * @param flags Ack/csum/notify flags in low 3 bits; number of segments minus 292 * 1 in next 2 bits; expected checksum in high 16 bits. 293 * @param confno Confirmation number to request, if notify flag set. 294 * @param csum0 Checksum descriptor; if zero, no checksum. 295 * @param va_F Virtual address of first segment. 296 * @param va_L Virtual address of last segment (third segment if 3 segments, 297 * fourth segment if 4 segments). 298 * @param len_F_L Length of first segment in low 16 bits; length of last 299 * segment in high 16 bits. 300 * @param va_M0 Virtual address of "middle 0" segment; this segment is sent 301 * second when there are three segments, and third if there are four. 302 * @param va_M1 Virtual address of "middle 1" segment; this segment is sent 303 * second when there are four segments. 304 * @param len_M0_M1 Length of middle 0 segment in low 16 bits; length of middle 305 * 1 segment, if 4 segments, in high 16 bits. 306 */ 307#define __netio_fastio_sendv_pkt_3_4(fastio_index, flags, confno, csum0, va_F, \ 308 va_L, len_F_L, va_M0, va_M1, len_M0_M1) \ 309 __netio_fastio9((fastio_index) + NETIO_FASTIO_SENDV_PKT, flags, confno, \ 310 csum0, va_F, va_L, len_F_L, va_M0, va_M1, len_M0_M1) 311 312/** Send vector of packets. 313 * @param fastio_index Fast I/O index. 314 * @param seqno Number of packets transmitted so far on this interface; 315 * used to decide which packets should be acknowledged. 316 * @param nentries Number of entries in vector. 317 * @param va Virtual address of start of vector entry array. 318 * @return 3-word netio_fastio_rv3_t structure. The structure's err member 319 * is an error code, or zero if no error. The val0 member is the 320 * updated value of seqno; it has been incremented by 1 for each 321 * packet sent. That increment may be less than nentries if an 322 * error occurred, or if some of the entries in the vector contain 323 * handles equal to NETIO_PKT_HANDLE_NONE. The val1 member is the 324 * updated value of nentries; it has been decremented by 1 for each 325 * vector entry processed. Again, that decrement may be less than 326 * nentries (leaving the returned value positive) if an error 327 * occurred. 328 */ 329#define __netio_fastio_send_pkt_vec(fastio_index, seqno, nentries, va) \ 330 __netio_fastio3_rv3((fastio_index) + NETIO_FASTIO_SEND_PKT_VEC, seqno, \ 331 nentries, va) 332 333 334/** An egress DMA command for LEPP. */ 335typedef struct 336{ 337 /** Is this a TSO transfer? 338 * 339 * NOTE: This field is always 0, to distinguish it from 340 * lepp_tso_cmd_t. It must come first! 341 */ 342 uint8_t tso : 1; 343 344 /** Unused padding bits. */ 345 uint8_t _unused : 3; 346 347 /** Should this packet be sent directly from caches instead of DRAM, 348 * using hash-for-home to locate the packet data? 349 */ 350 uint8_t hash_for_home : 1; 351 352 /** Should we compute a checksum? */ 353 uint8_t compute_checksum : 1; 354 355 /** Is this the final buffer for this packet? 356 * 357 * A single packet can be split over several input buffers (a "gather" 358 * operation). This flag indicates that this is the last buffer 359 * in a packet. 360 */ 361 uint8_t end_of_packet : 1; 362 363 /** Should LEPP advance 'comp_busy' when this DMA is fully finished? */ 364 uint8_t send_completion : 1; 365 366 /** High bits of Client Physical Address of the start of the buffer 367 * to be egressed. 368 * 369 * NOTE: Only 6 bits are actually needed here, as CPAs are 370 * currently 38 bits. So two bits could be scavenged from this. 371 */ 372 uint8_t cpa_hi; 373 374 /** The number of bytes to be egressed. */ 375 uint16_t length; 376 377 /** Low 32 bits of Client Physical Address of the start of the buffer 378 * to be egressed. 379 */ 380 uint32_t cpa_lo; 381 382 /** Checksum information (only used if 'compute_checksum'). */ 383 __netio_checksum_header_t checksum_data; 384 385} lepp_cmd_t; 386 387 388/** A chunk of physical memory for a TSO egress. */ 389typedef struct 390{ 391 /** The low bits of the CPA. */ 392 uint32_t cpa_lo; 393 /** The high bits of the CPA. */ 394 uint16_t cpa_hi : 15; 395 /** Should this packet be sent directly from caches instead of DRAM, 396 * using hash-for-home to locate the packet data? 397 */ 398 uint16_t hash_for_home : 1; 399 /** The length in bytes. */ 400 uint16_t length; 401} lepp_frag_t; 402 403 404/** An LEPP command that handles TSO. */ 405typedef struct 406{ 407 /** Is this a TSO transfer? 408 * 409 * NOTE: This field is always 1, to distinguish it from 410 * lepp_cmd_t. It must come first! 411 */ 412 uint8_t tso : 1; 413 414 /** Unused padding bits. */ 415 uint8_t _unused : 7; 416 417 /** Size of the header[] array in bytes. It must be in the range 418 * [40, 127], which are the smallest header for a TCP packet over 419 * Ethernet and the maximum possible prepend size supported by 420 * hardware, respectively. Note that the array storage must be 421 * padded out to a multiple of four bytes so that the following 422 * LEPP command is aligned properly. 423 */ 424 uint8_t header_size; 425 426 /** Byte offset of the IP header in header[]. */ 427 uint8_t ip_offset; 428 429 /** Byte offset of the TCP header in header[]. */ 430 uint8_t tcp_offset; 431 432 /** The number of bytes to use for the payload of each packet, 433 * except of course the last one, which may not have enough bytes. 434 * This means that each Ethernet packet except the last will have a 435 * size of header_size + payload_size. 436 */ 437 uint16_t payload_size; 438 439 /** The length of the 'frags' array that follows this struct. */ 440 uint16_t num_frags; 441 442 /** The actual frags. */ 443 lepp_frag_t frags[0 /* Variable-sized; num_frags entries. */]; 444 445 /* 446 * The packet header template logically follows frags[], 447 * but you can't declare that in C. 448 * 449 * uint32_t header[header_size_in_words_rounded_up]; 450 */ 451 452} lepp_tso_cmd_t; 453 454 455/** An LEPP completion ring entry. */ 456typedef void* lepp_comp_t; 457 458 459/** Maximum number of frags for one TSO command. This is adapted from 460 * linux's "MAX_SKB_FRAGS", and presumably over-estimates by one, for 461 * our page size of exactly 65536. We add one for a "body" fragment. 462 */ 463#define LEPP_MAX_FRAGS (65536 / HV_DEFAULT_PAGE_SIZE_SMALL + 2 + 1) 464 465/** Total number of bytes needed for an lepp_tso_cmd_t. */ 466#define LEPP_TSO_CMD_SIZE(num_frags, header_size) \ 467 (sizeof(lepp_tso_cmd_t) + \ 468 (num_frags) * sizeof(lepp_frag_t) + \ 469 (((header_size) + 3) & -4)) 470 471/** The size of the lepp "cmd" queue. */ 472#define LEPP_CMD_QUEUE_BYTES \ 473 (((CHIP_L2_CACHE_SIZE() - 2 * CHIP_L2_LINE_SIZE()) / \ 474 (sizeof(lepp_cmd_t) + sizeof(lepp_comp_t))) * sizeof(lepp_cmd_t)) 475 476/** The largest possible command that can go in lepp_queue_t::cmds[]. */ 477#define LEPP_MAX_CMD_SIZE LEPP_TSO_CMD_SIZE(LEPP_MAX_FRAGS, 128) 478 479/** The largest possible value of lepp_queue_t::cmd_{head, tail} (inclusive). 480 */ 481#define LEPP_CMD_LIMIT \ 482 (LEPP_CMD_QUEUE_BYTES - LEPP_MAX_CMD_SIZE) 483 484/** The maximum number of completions in an LEPP queue. */ 485#define LEPP_COMP_QUEUE_SIZE \ 486 ((LEPP_CMD_LIMIT + sizeof(lepp_cmd_t) - 1) / sizeof(lepp_cmd_t)) 487 488/** Increment an index modulo the queue size. */ 489#define LEPP_QINC(var) \ 490 (var = __insn_mnz(var - (LEPP_COMP_QUEUE_SIZE - 1), var + 1)) 491 492/** A queue used to convey egress commands from the client to LEPP. */ 493typedef struct 494{ 495 /** Index of first completion not yet processed by user code. 496 * If this is equal to comp_busy, there are no such completions. 497 * 498 * NOTE: This is only read/written by the user. 499 */ 500 unsigned int comp_head; 501 502 /** Index of first completion record not yet completed. 503 * If this is equal to comp_tail, there are no such completions. 504 * This index gets advanced (modulo LEPP_QUEUE_SIZE) whenever 505 * a command with the 'completion' bit set is finished. 506 * 507 * NOTE: This is only written by LEPP, only read by the user. 508 */ 509 volatile unsigned int comp_busy; 510 511 /** Index of the first empty slot in the completion ring. 512 * Entries from this up to but not including comp_head (in ring order) 513 * can be filled in with completion data. 514 * 515 * NOTE: This is only read/written by the user. 516 */ 517 unsigned int comp_tail; 518 519 /** Byte index of first command enqueued for LEPP but not yet processed. 520 * 521 * This is always divisible by sizeof(void*) and always <= LEPP_CMD_LIMIT. 522 * 523 * NOTE: LEPP advances this counter as soon as it no longer needs 524 * the cmds[] storage for this entry, but the transfer is not actually 525 * complete (i.e. the buffer pointed to by the command is no longer 526 * needed) until comp_busy advances. 527 * 528 * If this is equal to cmd_tail, the ring is empty. 529 * 530 * NOTE: This is only written by LEPP, only read by the user. 531 */ 532 volatile unsigned int cmd_head; 533 534 /** Byte index of first empty slot in the command ring. This field can 535 * be incremented up to but not equal to cmd_head (because that would 536 * mean the ring is empty). 537 * 538 * This is always divisible by sizeof(void*) and always <= LEPP_CMD_LIMIT. 539 * 540 * NOTE: This is read/written by the user, only read by LEPP. 541 */ 542 volatile unsigned int cmd_tail; 543 544 /** A ring of variable-sized egress DMA commands. 545 * 546 * NOTE: Only written by the user, only read by LEPP. 547 */ 548 char cmds[LEPP_CMD_QUEUE_BYTES] 549 __attribute__((aligned(CHIP_L2_LINE_SIZE()))); 550 551 /** A ring of user completion data. 552 * NOTE: Only read/written by the user. 553 */ 554 lepp_comp_t comps[LEPP_COMP_QUEUE_SIZE] 555 __attribute__((aligned(CHIP_L2_LINE_SIZE()))); 556} lepp_queue_t; 557 558 559/** An internal helper function for determining the number of entries 560 * available in a ring buffer, given that there is one sentinel. 561 */ 562static inline unsigned int 563_lepp_num_free_slots(unsigned int head, unsigned int tail) 564{ 565 /* 566 * One entry is reserved for use as a sentinel, to distinguish 567 * "empty" from "full". So we compute 568 * (head - tail - 1) % LEPP_QUEUE_SIZE, but without using a slow % operation. 569 */ 570 return (head - tail - 1) + ((head <= tail) ? LEPP_COMP_QUEUE_SIZE : 0); 571} 572 573 574/** Returns how many new comp entries can be enqueued. */ 575static inline unsigned int 576lepp_num_free_comp_slots(const lepp_queue_t* q) 577{ 578 return _lepp_num_free_slots(q->comp_head, q->comp_tail); 579} 580 581static inline int 582lepp_qsub(int v1, int v2) 583{ 584 int delta = v1 - v2; 585 return delta + ((delta >> 31) & LEPP_COMP_QUEUE_SIZE); 586} 587 588 589/** FIXME: Check this from linux, via a new "pwrite()" call. */ 590#define LIPP_VERSION 1 591 592 593/** We use exactly two bytes of alignment padding. */ 594#define LIPP_PACKET_PADDING 2 595 596/** The minimum size of a "small" buffer (including the padding). */ 597#define LIPP_SMALL_PACKET_SIZE 128 598 599/* 600 * NOTE: The following two values should total to less than around 601 * 13582, to keep the total size used for "lipp_state_t" below 64K. 602 */ 603 604/** The maximum number of "small" buffers. 605 * This is enough for 53 network cpus with 128 credits. Note that 606 * if these are exhausted, we will fall back to using large buffers. 607 */ 608#define LIPP_SMALL_BUFFERS 6785 609 610/** The maximum number of "large" buffers. 611 * This is enough for 53 network cpus with 128 credits. 612 */ 613#define LIPP_LARGE_BUFFERS 6785 614 615#endif /* __DRV_XGBE_INTF_H__ */ 616