linux/drivers/net/ethernet/cavium/liquidio/octeon_droq.h
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   1/**********************************************************************
   2 * Author: Cavium, Inc.
   3 *
   4 * Contact: support@cavium.com
   5 *          Please include "LiquidIO" in the subject.
   6 *
   7 * Copyright (c) 2003-2015 Cavium, Inc.
   8 *
   9 * This file is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License, Version 2, as
  11 * published by the Free Software Foundation.
  12 *
  13 * This file is distributed in the hope that it will be useful, but
  14 * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
  15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
  16 * NONINFRINGEMENT.  See the GNU General Public License for more
  17 * details.
  18 *
  19 * This file may also be available under a different license from Cavium.
  20 * Contact Cavium, Inc. for more information
  21 **********************************************************************/
  22
  23/*!  \file  octeon_droq.h
  24 *   \brief Implementation of Octeon Output queues. "Output" is with
  25 *   respect to the Octeon device on the NIC. From this driver's point of
  26 *   view they are ingress queues.
  27 */
  28
  29#ifndef __OCTEON_DROQ_H__
  30#define __OCTEON_DROQ_H__
  31
  32/* Default number of packets that will be processed in one iteration. */
  33#define MAX_PACKET_BUDGET 0xFFFFFFFF
  34
  35/** Octeon descriptor format.
  36 *  The descriptor ring is made of descriptors which have 2 64-bit values:
  37 *  -# Physical (bus) address of the data buffer.
  38 *  -# Physical (bus) address of a octeon_droq_info structure.
  39 *  The Octeon device DMA's incoming packets and its information at the address
  40 *  given by these descriptor fields.
  41 */
  42struct octeon_droq_desc {
  43        /** The buffer pointer */
  44        u64 buffer_ptr;
  45
  46        /** The Info pointer */
  47        u64 info_ptr;
  48};
  49
  50#define OCT_DROQ_DESC_SIZE    (sizeof(struct octeon_droq_desc))
  51
  52/** Information about packet DMA'ed by Octeon.
  53 *  The format of the information available at Info Pointer after Octeon
  54 *  has posted a packet. Not all descriptors have valid information. Only
  55 *  the Info field of the first descriptor for a packet has information
  56 *  about the packet.
  57 */
  58struct octeon_droq_info {
  59        /** The Output Receive Header. */
  60        union octeon_rh rh;
  61
  62        /** The Length of the packet. */
  63        u64 length;
  64};
  65
  66#define OCT_DROQ_INFO_SIZE   (sizeof(struct octeon_droq_info))
  67
  68/** Pointer to data buffer.
  69 *  Driver keeps a pointer to the data buffer that it made available to
  70 *  the Octeon device. Since the descriptor ring keeps physical (bus)
  71 *  addresses, this field is required for the driver to keep track of
  72 *  the virtual address pointers.
  73*/
  74struct octeon_recv_buffer {
  75        /** Packet buffer, including metadata. */
  76        void *buffer;
  77
  78        /** Data in the packet buffer.  */
  79        u8 *data;
  80};
  81
  82#define OCT_DROQ_RECVBUF_SIZE    (sizeof(struct octeon_recv_buffer))
  83
  84/** Output Queue statistics. Each output queue has four stats fields. */
  85struct oct_droq_stats {
  86        /** Number of packets received in this queue. */
  87        u64 pkts_received;
  88
  89        /** Bytes received by this queue. */
  90        u64 bytes_received;
  91
  92        /** Packets dropped due to no dispatch function. */
  93        u64 dropped_nodispatch;
  94
  95        /** Packets dropped due to no memory available. */
  96        u64 dropped_nomem;
  97
  98        /** Packets dropped due to large number of pkts to process. */
  99        u64 dropped_toomany;
 100
 101        /** Number of packets  sent to stack from this queue. */
 102        u64 rx_pkts_received;
 103
 104        /** Number of Bytes sent to stack from this queue. */
 105        u64 rx_bytes_received;
 106
 107        /** Num of Packets dropped due to receive path failures. */
 108        u64 rx_dropped;
 109};
 110
 111#define POLL_EVENT_INTR_ARRIVED  1
 112#define POLL_EVENT_PROCESS_PKTS  2
 113#define POLL_EVENT_PENDING_PKTS  3
 114#define POLL_EVENT_ENABLE_INTR   4
 115
 116/* The maximum number of buffers that can be dispatched from the
 117 * output/dma queue. Set to 64 assuming 1K buffers in DROQ and the fact that
 118 * max packet size from DROQ is 64K.
 119 */
 120#define    MAX_RECV_BUFS    64
 121
 122/** Receive Packet format used when dispatching output queue packets
 123 *  with non-raw opcodes.
 124 *  The received packet will be sent to the upper layers using this
 125 *  structure which is passed as a parameter to the dispatch function
 126 */
 127struct octeon_recv_pkt {
 128        /**  Number of buffers in this received packet */
 129        u16 buffer_count;
 130
 131        /** Id of the device that is sending the packet up */
 132        u16 octeon_id;
 133
 134        /** Length of data in the packet buffer */
 135        u32 length;
 136
 137        /** The receive header */
 138        union octeon_rh rh;
 139
 140        /** Pointer to the OS-specific packet buffer */
 141        void *buffer_ptr[MAX_RECV_BUFS];
 142
 143        /** Size of the buffers pointed to by ptr's in buffer_ptr */
 144        u32 buffer_size[MAX_RECV_BUFS];
 145};
 146
 147#define OCT_RECV_PKT_SIZE    (sizeof(struct octeon_recv_pkt))
 148
 149/** The first parameter of a dispatch function.
 150 *  For a raw mode opcode, the driver dispatches with the device
 151 *  pointer in this structure.
 152 *  For non-raw mode opcode, the driver dispatches the recv_pkt
 153 *  created to contain the buffers with data received from Octeon.
 154 *  ---------------------
 155 *  |     *recv_pkt ----|---
 156 *  |-------------------|   |
 157 *  | 0 or more bytes   |   |
 158 *  | reserved by driver|   |
 159 *  |-------------------|<-/
 160 *  | octeon_recv_pkt   |
 161 *  |                   |
 162 *  |___________________|
 163 */
 164struct octeon_recv_info {
 165        void *rsvd;
 166        struct octeon_recv_pkt *recv_pkt;
 167};
 168
 169#define  OCT_RECV_INFO_SIZE    (sizeof(struct octeon_recv_info))
 170
 171/** Allocate a recv_info structure. The recv_pkt pointer in the recv_info
 172 *  structure is filled in before this call returns.
 173 *  @param extra_bytes - extra bytes to be allocated at the end of the recv info
 174 *                       structure.
 175 *  @return - pointer to a newly allocated recv_info structure.
 176 */
 177static inline struct octeon_recv_info *octeon_alloc_recv_info(int extra_bytes)
 178{
 179        struct octeon_recv_info *recv_info;
 180        u8 *buf;
 181
 182        buf = kmalloc(OCT_RECV_PKT_SIZE + OCT_RECV_INFO_SIZE +
 183                      extra_bytes, GFP_ATOMIC);
 184        if (!buf)
 185                return NULL;
 186
 187        recv_info = (struct octeon_recv_info *)buf;
 188        recv_info->recv_pkt =
 189                (struct octeon_recv_pkt *)(buf + OCT_RECV_INFO_SIZE);
 190        recv_info->rsvd = NULL;
 191        if (extra_bytes)
 192                recv_info->rsvd = buf + OCT_RECV_INFO_SIZE + OCT_RECV_PKT_SIZE;
 193
 194        return recv_info;
 195}
 196
 197/** Free a recv_info structure.
 198 *  @param recv_info - Pointer to receive_info to be freed
 199 */
 200static inline void octeon_free_recv_info(struct octeon_recv_info *recv_info)
 201{
 202        kfree(recv_info);
 203}
 204
 205typedef int (*octeon_dispatch_fn_t)(struct octeon_recv_info *, void *);
 206
 207/** Used by NIC module to register packet handler and to get device
 208 * information for each octeon device.
 209 */
 210struct octeon_droq_ops {
 211        /** This registered function will be called by the driver with
 212         *  the octeon id, pointer to buffer from droq and length of
 213         *  data in the buffer. The receive header gives the port
 214         *  number to the caller.  Function pointer is set by caller.
 215         */
 216        void (*fptr)(u32, void *, u32, union octeon_rh *, void *);
 217
 218        /* This function will be called by the driver for all NAPI related
 219         * events. The first param is the octeon id. The second param is the
 220         * output queue number. The third is the NAPI event that occurred.
 221         */
 222        void (*napi_fn)(void *);
 223
 224        u32 poll_mode;
 225
 226        /** Flag indicating if the DROQ handler should drop packets that
 227         *  it cannot handle in one iteration. Set by caller.
 228         */
 229        u32 drop_on_max;
 230};
 231
 232/** The Descriptor Ring Output Queue structure.
 233 *  This structure has all the information required to implement a
 234 *  Octeon DROQ.
 235 */
 236struct octeon_droq {
 237        /** A spinlock to protect access to this ring. */
 238        spinlock_t lock;
 239
 240        u32 q_no;
 241
 242        struct octeon_droq_ops ops;
 243
 244        struct octeon_device *oct_dev;
 245
 246        /** The 8B aligned descriptor ring starts at this address. */
 247        struct octeon_droq_desc *desc_ring;
 248
 249        /** Index in the ring where the driver should read the next packet */
 250        u32 read_idx;
 251
 252        /** Index in the ring where Octeon will write the next packet */
 253        u32 write_idx;
 254
 255        /** Index in the ring where the driver will refill the descriptor's
 256         * buffer
 257         */
 258        u32 refill_idx;
 259
 260        /** Packets pending to be processed */
 261        atomic_t pkts_pending;
 262
 263        /** Number of  descriptors in this ring. */
 264        u32 max_count;
 265
 266        /** The number of descriptors pending refill. */
 267        u32 refill_count;
 268
 269        u32 pkts_per_intr;
 270        u32 refill_threshold;
 271
 272        /** The max number of descriptors in DROQ without a buffer.
 273         * This field is used to keep track of empty space threshold. If the
 274         * refill_count reaches this value, the DROQ cannot accept a max-sized
 275         * (64K) packet.
 276         */
 277        u32 max_empty_descs;
 278
 279        /** The 8B aligned info ptrs begin from this address. */
 280        struct octeon_droq_info *info_list;
 281
 282        /** The receive buffer list. This list has the virtual addresses of the
 283         * buffers.
 284         */
 285        struct octeon_recv_buffer *recv_buf_list;
 286
 287        /** The size of each buffer pointed by the buffer pointer. */
 288        u32 buffer_size;
 289
 290        /** Pointer to the mapped packet credit register.
 291         * Host writes number of info/buffer ptrs available to this register
 292         */
 293        void  __iomem *pkts_credit_reg;
 294
 295        /** Pointer to the mapped packet sent register.
 296         * Octeon writes the number of packets DMA'ed to host memory
 297         * in this register.
 298         */
 299        void __iomem *pkts_sent_reg;
 300
 301        struct list_head dispatch_list;
 302
 303        /** Statistics for this DROQ. */
 304        struct oct_droq_stats stats;
 305
 306        /** DMA mapped address of the DROQ descriptor ring. */
 307        size_t desc_ring_dma;
 308
 309        /** Info ptr list are allocated at this virtual address. */
 310        size_t info_base_addr;
 311
 312        /** DMA mapped address of the info list */
 313        size_t info_list_dma;
 314
 315        /** Allocated size of info list. */
 316        u32 info_alloc_size;
 317
 318        /** application context */
 319        void *app_ctx;
 320
 321        struct napi_struct napi;
 322
 323        u32 cpu_id;
 324
 325        struct call_single_data csd;
 326};
 327
 328#define OCT_DROQ_SIZE   (sizeof(struct octeon_droq))
 329
 330/**
 331 *  Allocates space for the descriptor ring for the droq and sets the
 332 *   base addr, num desc etc in Octeon registers.
 333 *
 334 * @param  oct_dev    - pointer to the octeon device structure
 335 * @param  q_no       - droq no. ranges from 0 - 3.
 336 * @param app_ctx     - pointer to application context
 337 * @return Success: 0    Failure: 1
 338*/
 339int octeon_init_droq(struct octeon_device *oct_dev,
 340                     u32 q_no,
 341                     u32 num_descs,
 342                     u32 desc_size,
 343                     void *app_ctx);
 344
 345/**
 346 *  Frees the space for descriptor ring for the droq.
 347 *
 348 *  @param oct_dev - pointer to the octeon device structure
 349 *  @param q_no    - droq no. ranges from 0 - 3.
 350 *  @return:    Success: 0    Failure: 1
 351*/
 352int octeon_delete_droq(struct octeon_device *oct_dev, u32 q_no);
 353
 354/** Register a change in droq operations. The ops field has a pointer to a
 355 * function which will called by the DROQ handler for all packets arriving
 356 * on output queues given by q_no irrespective of the type of packet.
 357 * The ops field also has a flag which if set tells the DROQ handler to
 358 * drop packets if it receives more than what it can process in one
 359 * invocation of the handler.
 360 * @param oct       - octeon device
 361 * @param q_no      - octeon output queue number (0 <= q_no <= MAX_OCTEON_DROQ-1
 362 * @param ops       - the droq_ops settings for this queue
 363 * @return          - 0 on success, -ENODEV or -EINVAL on error.
 364 */
 365int
 366octeon_register_droq_ops(struct octeon_device *oct,
 367                         u32 q_no,
 368                         struct octeon_droq_ops *ops);
 369
 370/** Resets the function pointer and flag settings made by
 371 * octeon_register_droq_ops(). After this routine is called, the DROQ handler
 372 * will lookup dispatch function for each arriving packet on the output queue
 373 * given by q_no.
 374 * @param oct       - octeon device
 375 * @param q_no      - octeon output queue number (0 <= q_no <= MAX_OCTEON_DROQ-1
 376 * @return          - 0 on success, -ENODEV or -EINVAL on error.
 377 */
 378int octeon_unregister_droq_ops(struct octeon_device *oct, u32 q_no);
 379
 380/**   Register a dispatch function for a opcode/subcode. The driver will call
 381 *    this dispatch function when it receives a packet with the given
 382 *    opcode/subcode in its output queues along with the user specified
 383 *    argument.
 384 *    @param  oct        - the octeon device to register with.
 385 *    @param  opcode     - the opcode for which the dispatch will be registered.
 386 *    @param  subcode    - the subcode for which the dispatch will be registered
 387 *    @param  fn         - the dispatch function.
 388 *    @param  fn_arg     - user specified that will be passed along with the
 389 *                         dispatch function by the driver.
 390 *    @return Success: 0; Failure: 1
 391 */
 392int octeon_register_dispatch_fn(struct octeon_device *oct,
 393                                u16 opcode,
 394                                u16 subcode,
 395                                octeon_dispatch_fn_t fn, void *fn_arg);
 396
 397/**  Remove registration for an opcode/subcode. This will delete the mapping for
 398 *   an opcode/subcode. The dispatch function will be unregistered and will no
 399 *   longer be called if a packet with the opcode/subcode arrives in the driver
 400 *   output queues.
 401 *   @param  oct        -  the octeon device to unregister from.
 402 *   @param  opcode     -  the opcode to be unregistered.
 403 *   @param  subcode    -  the subcode to be unregistered.
 404 *
 405 *   @return Success: 0; Failure: 1
 406 */
 407int octeon_unregister_dispatch_fn(struct octeon_device *oct,
 408                                  u16 opcode,
 409                                  u16 subcode);
 410
 411void octeon_droq_print_stats(void);
 412
 413u32 octeon_droq_check_hw_for_pkts(struct octeon_device *oct,
 414                                  struct octeon_droq *droq);
 415
 416int octeon_create_droq(struct octeon_device *oct, u32 q_no,
 417                       u32 num_descs, u32 desc_size, void *app_ctx);
 418
 419int octeon_droq_process_packets(struct octeon_device *oct,
 420                                struct octeon_droq *droq,
 421                                u32 budget);
 422
 423int octeon_process_droq_poll_cmd(struct octeon_device *oct, u32 q_no,
 424                                 int cmd, u32 arg);
 425
 426#endif  /*__OCTEON_DROQ_H__ */
 427