kernel/drivers/net/wireless/brcm80211/brcmfmac/commonring.c

   1 /* Copyright (c) 2014 Broadcom Corporation
   2  *
   3  * Permission to use, copy, modify, and/or distribute this software for any
   4  * purpose with or without fee is hereby granted, provided that the above
   5  * copyright notice and this permission notice appear in all copies.
   6  *
   7  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   8  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   9  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  10  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  11  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  12  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  13  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  14  */
  15
  16 #include <linux/types.h>
  17 #include <linux/netdevice.h>
  18
  19 #include <brcmu_utils.h>
  20 #include <brcmu_wifi.h>
  21
  22 #include "core.h"
  23 #include "commonring.h"
  24
  25 void brcmf_commonring_register_cb(struct brcmf_commonring *commonring,
  26                                   int (*cr_ring_bell)(void *ctx),
  27                                   int (*cr_update_rptr)(void *ctx),
  28                                   int (*cr_update_wptr)(void *ctx),
  29                                   int (*cr_write_rptr)(void *ctx),
  30                                   int (*cr_write_wptr)(void *ctx), void *ctx)
  31 {
  32         commonring->cr_ring_bell = cr_ring_bell;
  33         commonring->cr_update_rptr = cr_update_rptr;
  34         commonring->cr_update_wptr = cr_update_wptr;
  35         commonring->cr_write_rptr = cr_write_rptr;
  36         commonring->cr_write_wptr = cr_write_wptr;
  37         commonring->cr_ctx = ctx;
  38 }
  39
  40
  41 void brcmf_commonring_config(struct brcmf_commonring *commonring, u16 depth,
  42                              u16 item_len, void *buf_addr)
  43 {
  44         commonring->depth = depth;
  45         commonring->item_len = item_len;
  46         commonring->buf_addr = buf_addr;
  47         if (!commonring->inited) {
  48                 spin_lock_init(&commonring->lock);
  49                 commonring->inited = true;
  50         }
  51         commonring->r_ptr = 0;
  52         if (commonring->cr_write_rptr)
  53                 commonring->cr_write_rptr(commonring->cr_ctx);
  54         commonring->w_ptr = 0;
  55         if (commonring->cr_write_wptr)
  56                 commonring->cr_write_wptr(commonring->cr_ctx);
  57         commonring->f_ptr = 0;
  58 }
  59
  60
  61 void brcmf_commonring_lock(struct brcmf_commonring *commonring)
  62                 __acquires(&commonring->lock)
  63 {
  64         unsigned long flags;
  65
  66         spin_lock_irqsave(&commonring->lock, flags);
  67         commonring->flags = flags;
  68 }
  69
  70
  71 void brcmf_commonring_unlock(struct brcmf_commonring *commonring)
  72                 __releases(&commonring->lock)
  73 {
  74         spin_unlock_irqrestore(&commonring->lock, commonring->flags);
  75 }
  76
  77
  78 bool brcmf_commonring_write_available(struct brcmf_commonring *commonring)
  79 {
  80         u16 available;
  81         bool retry = true;
  82
  83 again:
  84         if (commonring->r_ptr <= commonring->w_ptr)
  85                 available = commonring->depth - commonring->w_ptr +
  86                             commonring->r_ptr;
  87         else
  88                 available = commonring->r_ptr - commonring->w_ptr;
  89
  90         if (available > 1) {
  91                 if (!commonring->was_full)
  92                         return true;
  93                 if (available > commonring->depth / 8) {
  94                         commonring->was_full = false;
  95                         return true;
  96                 }
  97                 if (retry) {
  98                         if (commonring->cr_update_rptr)
  99                                 commonring->cr_update_rptr(commonring->cr_ctx);
 100                         retry = false;
 101                         goto again;
 102                 }
 103                 return false;
 104         }
 105
 106         if (retry) {
 107                 if (commonring->cr_update_rptr)
 108                         commonring->cr_update_rptr(commonring->cr_ctx);
 109                 retry = false;
 110                 goto again;
 111         }
 112
 113         commonring->was_full = true;
 114         return false;
 115 }
 116
 117
 118 void *brcmf_commonring_reserve_for_write(struct brcmf_commonring *commonring)
 119 {
 120         void *ret_ptr;
 121         u16 available;
 122         bool retry = true;
 123
 124 again:
 125         if (commonring->r_ptr <= commonring->w_ptr)
 126                 available = commonring->depth - commonring->w_ptr +
 127                             commonring->r_ptr;
 128         else
 129                 available = commonring->r_ptr - commonring->w_ptr;
 130
 131         if (available > 1) {
 132                 ret_ptr = commonring->buf_addr +
 133                           (commonring->w_ptr * commonring->item_len);
 134                 commonring->w_ptr++;
 135                 if (commonring->w_ptr == commonring->depth)
 136                         commonring->w_ptr = 0;
 137                 return ret_ptr;
 138         }
 139
 140         if (retry) {
 141                 if (commonring->cr_update_rptr)
 142                         commonring->cr_update_rptr(commonring->cr_ctx);
 143                 retry = false;
 144                 goto again;
 145         }
 146
 147         commonring->was_full = true;
 148         return NULL;
 149 }
 150
 151
 152 void *
 153 brcmf_commonring_reserve_for_write_multiple(struct brcmf_commonring *commonring,
 154                                             u16 n_items, u16 *alloced)
 155 {
 156         void *ret_ptr;
 157         u16 available;
 158         bool retry = true;
 159
 160 again:
 161         if (commonring->r_ptr <= commonring->w_ptr)
 162                 available = commonring->depth - commonring->w_ptr +
 163                             commonring->r_ptr;
 164         else
 165                 available = commonring->r_ptr - commonring->w_ptr;
 166
 167         if (available > 1) {
 168                 ret_ptr = commonring->buf_addr +
 169                           (commonring->w_ptr * commonring->item_len);
 170                 *alloced = min_t(u16, n_items, available - 1);
 171                 if (*alloced + commonring->w_ptr > commonring->depth)
 172                         *alloced = commonring->depth - commonring->w_ptr;
 173                 commonring->w_ptr += *alloced;
 174                 if (commonring->w_ptr == commonring->depth)
 175                         commonring->w_ptr = 0;
 176                 return ret_ptr;
 177         }
 178
 179         if (retry) {
 180                 if (commonring->cr_update_rptr)
 181                         commonring->cr_update_rptr(commonring->cr_ctx);
 182                 retry = false;
 183                 goto again;
 184         }
 185
 186         commonring->was_full = true;
 187         return NULL;
 188 }
 189
 190
 191 int brcmf_commonring_write_complete(struct brcmf_commonring *commonring)
 192 {
 193         void *address;
 194
 195         address = commonring->buf_addr;
 196         address += (commonring->f_ptr * commonring->item_len);
 197         if (commonring->f_ptr > commonring->w_ptr) {
 198                 address = commonring->buf_addr;
 199                 commonring->f_ptr = 0;
 200         }
 201
 202         commonring->f_ptr = commonring->w_ptr;
 203
 204         if (commonring->cr_write_wptr)
 205                 commonring->cr_write_wptr(commonring->cr_ctx);
 206         if (commonring->cr_ring_bell)
 207                 return commonring->cr_ring_bell(commonring->cr_ctx);
 208
 209         return -EIO;
 210 }
 211
 212
 213 void brcmf_commonring_write_cancel(struct brcmf_commonring *commonring,
 214                                    u16 n_items)
 215 {
 216         if (commonring->w_ptr == 0)
 217                 commonring->w_ptr = commonring->depth - n_items;
 218         else
 219                 commonring->w_ptr -= n_items;
 220 }
 221
 222
 223 void *brcmf_commonring_get_read_ptr(struct brcmf_commonring *commonring,
 224                                     u16 *n_items)
 225 {
 226         if (commonring->cr_update_wptr)
 227                 commonring->cr_update_wptr(commonring->cr_ctx);
 228
 229         *n_items = (commonring->w_ptr >= commonring->r_ptr) ?
 230                                 (commonring->w_ptr - commonring->r_ptr) :
 231                                 (commonring->depth - commonring->r_ptr);
 232
 233         if (*n_items == 0)
 234                 return NULL;
 235
 236         return commonring->buf_addr +
 237                (commonring->r_ptr * commonring->item_len);
 238 }
 239
 240
 241 int brcmf_commonring_read_complete(struct brcmf_commonring *commonring,
 242                                    u16 n_items)
 243 {
 244         commonring->r_ptr += n_items;
 245         if (commonring->r_ptr == commonring->depth)
 246                 commonring->r_ptr = 0;
 247
 248         if (commonring->cr_write_rptr)
 249                 return commonring->cr_write_rptr(commonring->cr_ctx);
 250
 251         return -EIO;
 252 }