drivers/net/ethernet/cisco/enic/vnic_rq.h

   1 /*
   2  * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
   3  * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
   4  *
   5  * This program is free software; you may redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; version 2 of the License.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  10  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  11  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  12  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  13  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  14  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  15  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  16  * SOFTWARE.
  17  *
  18  */
  19
  20 #ifndef _VNIC_RQ_H_
  21 #define _VNIC_RQ_H_
  22
  23 #include <linux/pci.h>
  24 #include <linux/netdevice.h>
  25
  26 #include "vnic_dev.h"
  27 #include "vnic_cq.h"
  28
  29 /* Receive queue control */
  30 struct vnic_rq_ctrl {
  31         u64 ring_base;                  /* 0x00 */
  32         u32 ring_size;                  /* 0x08 */
  33         u32 pad0;
  34         u32 posted_index;               /* 0x10 */
  35         u32 pad1;
  36         u32 cq_index;                   /* 0x18 */
  37         u32 pad2;
  38         u32 enable;                     /* 0x20 */
  39         u32 pad3;
  40         u32 running;                    /* 0x28 */
  41         u32 pad4;
  42         u32 fetch_index;                /* 0x30 */
  43         u32 pad5;
  44         u32 error_interrupt_enable;     /* 0x38 */
  45         u32 pad6;
  46         u32 error_interrupt_offset;     /* 0x40 */
  47         u32 pad7;
  48         u32 error_status;               /* 0x48 */
  49         u32 pad8;
  50         u32 dropped_packet_count;       /* 0x50 */
  51         u32 pad9;
  52         u32 dropped_packet_count_rc;    /* 0x58 */
  53         u32 pad10;
  54 };
  55
  56 /* Break the vnic_rq_buf allocations into blocks of 32/64 entries */
  57 #define VNIC_RQ_BUF_MIN_BLK_ENTRIES 32
  58 #define VNIC_RQ_BUF_DFLT_BLK_ENTRIES 64
  59 #define VNIC_RQ_BUF_BLK_ENTRIES(entries) \
  60         ((unsigned int)((entries < VNIC_RQ_BUF_DFLT_BLK_ENTRIES) ? \
  61         VNIC_RQ_BUF_MIN_BLK_ENTRIES : VNIC_RQ_BUF_DFLT_BLK_ENTRIES))
  62 #define VNIC_RQ_BUF_BLK_SZ(entries) \
  63         (VNIC_RQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_rq_buf))
  64 #define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
  65         DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES(entries))
  66 #define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
  67
  68 struct vnic_rq_buf {
  69         struct vnic_rq_buf *next;
  70         dma_addr_t dma_addr;
  71         void *os_buf;
  72         unsigned int os_buf_index;
  73         unsigned int len;
  74         unsigned int index;
  75         void *desc;
  76         uint64_t wr_id;
  77 };
  78
  79 enum enic_poll_state {
  80         ENIC_POLL_STATE_IDLE,
  81         ENIC_POLL_STATE_NAPI,
  82         ENIC_POLL_STATE_POLL
  83 };
  84
  85 struct vnic_rq {
  86         unsigned int index;
  87         struct vnic_dev *vdev;
  88         struct vnic_rq_ctrl __iomem *ctrl;              /* memory-mapped */
  89         struct vnic_dev_ring ring;
  90         struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
  91         struct vnic_rq_buf *to_use;
  92         struct vnic_rq_buf *to_clean;
  93         void *os_buf_head;
  94         unsigned int pkts_outstanding;
  95 #ifdef CONFIG_NET_RX_BUSY_POLL
  96         atomic_t bpoll_state;
  97 #endif /* CONFIG_NET_RX_BUSY_POLL */
  98 };
  99
 100 static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
 101 {
 102         /* how many does SW own? */
 103         return rq->ring.desc_avail;
 104 }
 105
 106 static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
 107 {
 108         /* how many does HW own? */
 109         return rq->ring.desc_count - rq->ring.desc_avail - 1;
 110 }
 111
 112 static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
 113 {
 114         return rq->to_use->desc;
 115 }
 116
 117 static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
 118 {
 119         return rq->to_use->index;
 120 }
 121
 122 static inline void vnic_rq_post(struct vnic_rq *rq,
 123         void *os_buf, unsigned int os_buf_index,
 124         dma_addr_t dma_addr, unsigned int len,
 125         uint64_t wrid)
 126 {
 127         struct vnic_rq_buf *buf = rq->to_use;
 128
 129         buf->os_buf = os_buf;
 130         buf->os_buf_index = os_buf_index;
 131         buf->dma_addr = dma_addr;
 132         buf->len = len;
 133         buf->wr_id = wrid;
 134
 135         buf = buf->next;
 136         rq->to_use = buf;
 137         rq->ring.desc_avail--;
 138
 139         /* Move the posted_index every nth descriptor
 140          */
 141
 142 #ifndef VNIC_RQ_RETURN_RATE
 143 #define VNIC_RQ_RETURN_RATE             0xf     /* keep 2^n - 1 */
 144 #endif
 145
 146         if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
 147                 /* Adding write memory barrier prevents compiler and/or CPU
 148                  * reordering, thus avoiding descriptor posting before
 149                  * descriptor is initialized. Otherwise, hardware can read
 150                  * stale descriptor fields.
 151                  */
 152                 wmb();
 153                 iowrite32(buf->index, &rq->ctrl->posted_index);
 154         }
 155 }
 156
 157 static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
 158 {
 159         rq->ring.desc_avail += count;
 160 }
 161
 162 enum desc_return_options {
 163         VNIC_RQ_RETURN_DESC,
 164         VNIC_RQ_DEFER_RETURN_DESC,
 165 };
 166
 167 static inline void vnic_rq_service(struct vnic_rq *rq,
 168         struct cq_desc *cq_desc, u16 completed_index,
 169         int desc_return, void (*buf_service)(struct vnic_rq *rq,
 170         struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
 171         int skipped, void *opaque), void *opaque)
 172 {
 173         struct vnic_rq_buf *buf;
 174         int skipped;
 175
 176         buf = rq->to_clean;
 177         while (1) {
 178
 179                 skipped = (buf->index != completed_index);
 180
 181                 (*buf_service)(rq, cq_desc, buf, skipped, opaque);
 182
 183                 if (desc_return == VNIC_RQ_RETURN_DESC)
 184                         rq->ring.desc_avail++;
 185
 186                 rq->to_clean = buf->next;
 187
 188                 if (!skipped)
 189                         break;
 190
 191                 buf = rq->to_clean;
 192         }
 193 }
 194
 195 static inline int vnic_rq_fill(struct vnic_rq *rq,
 196         int (*buf_fill)(struct vnic_rq *rq))
 197 {
 198         int err;
 199
 200         while (vnic_rq_desc_avail(rq) > 0) {
 201
 202                 err = (*buf_fill)(rq);
 203                 if (err)
 204                         return err;
 205         }
 206
 207         return 0;
 208 }
 209
 210 #ifdef CONFIG_NET_RX_BUSY_POLL
 211 static inline void enic_busy_poll_init_lock(struct vnic_rq *rq)
 212 {
 213         atomic_set(&rq->bpoll_state, ENIC_POLL_STATE_IDLE);
 214 }
 215
 216 static inline bool enic_poll_lock_napi(struct vnic_rq *rq)
 217 {
 218         int rc = atomic_cmpxchg(&rq->bpoll_state, ENIC_POLL_STATE_IDLE,
 219                                 ENIC_POLL_STATE_NAPI);
 220
 221         return (rc == ENIC_POLL_STATE_IDLE);
 222 }
 223
 224 static inline void enic_poll_unlock_napi(struct vnic_rq *rq,
 225                                          struct napi_struct *napi)
 226 {
 227         WARN_ON(atomic_read(&rq->bpoll_state) != ENIC_POLL_STATE_NAPI);
 228         napi_gro_flush(napi, false);
 229         atomic_set(&rq->bpoll_state, ENIC_POLL_STATE_IDLE);
 230 }
 231
 232 static inline bool enic_poll_lock_poll(struct vnic_rq *rq)
 233 {
 234         int rc = atomic_cmpxchg(&rq->bpoll_state, ENIC_POLL_STATE_IDLE,
 235                                 ENIC_POLL_STATE_POLL);
 236
 237         return (rc == ENIC_POLL_STATE_IDLE);
 238 }
 239
 240
 241 static inline void enic_poll_unlock_poll(struct vnic_rq *rq)
 242 {
 243         WARN_ON(atomic_read(&rq->bpoll_state) != ENIC_POLL_STATE_POLL);
 244         atomic_set(&rq->bpoll_state, ENIC_POLL_STATE_IDLE);
 245 }
 246
 247 static inline bool enic_poll_busy_polling(struct vnic_rq *rq)
 248 {
 249         return atomic_read(&rq->bpoll_state) & ENIC_POLL_STATE_POLL;
 250 }
 251
 252 #else
 253
 254 static inline void enic_busy_poll_init_lock(struct vnic_rq *rq)
 255 {
 256 }
 257
 258 static inline bool enic_poll_lock_napi(struct vnic_rq *rq)
 259 {
 260         return true;
 261 }
 262
 263 static inline bool enic_poll_unlock_napi(struct vnic_rq *rq,
 264                                          struct napi_struct *napi)
 265 {
 266         return false;
 267 }
 268
 269 static inline bool enic_poll_lock_poll(struct vnic_rq *rq)
 270 {
 271         return false;
 272 }
 273
 274 static inline bool enic_poll_unlock_poll(struct vnic_rq *rq)
 275 {
 276         return false;
 277 }
 278
 279 static inline bool enic_poll_ll_polling(struct vnic_rq *rq)
 280 {
 281         return false;
 282 }
 283 #endif /* CONFIG_NET_RX_BUSY_POLL */
 284
 285 void vnic_rq_free(struct vnic_rq *rq);
 286 int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
 287         unsigned int desc_count, unsigned int desc_size);
 288 void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
 289         unsigned int error_interrupt_enable,
 290         unsigned int error_interrupt_offset);
 291 unsigned int vnic_rq_error_status(struct vnic_rq *rq);
 292 void vnic_rq_enable(struct vnic_rq *rq);
 293 int vnic_rq_disable(struct vnic_rq *rq);
 294 void vnic_rq_clean(struct vnic_rq *rq,
 295         void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
 296
 297 #endif /* _VNIC_RQ_H_ */