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
  26 /* dma flushing needs implementation for mips and arm platforms. Should
  27  * be put in util. Note, this is not real flushing. It is virtual non
  28  * cached memory. Only write buffers should have to be drained. Though
  29  * this may be different depending on platform......
  30  * SEE ALSO msgbuf.c
  31  */
  32 #define brcmf_dma_flush(addr, len)
  33 #define brcmf_dma_invalidate_cache(addr, len)
  34
  35
  36 void brcmf_commonring_register_cb(struct brcmf_commonring *commonring,
  37                                   int (*cr_ring_bell)(void *ctx),
  38                                   int (*cr_update_rptr)(void *ctx),
  39                                   int (*cr_update_wptr)(void *ctx),
  40                                   int (*cr_write_rptr)(void *ctx),
  41                                   int (*cr_write_wptr)(void *ctx), void *ctx)
  42 {
  43         commonring->cr_ring_bell = cr_ring_bell;
  44         commonring->cr_update_rptr = cr_update_rptr;
  45         commonring->cr_update_wptr = cr_update_wptr;
  46         commonring->cr_write_rptr = cr_write_rptr;
  47         commonring->cr_write_wptr = cr_write_wptr;
  48         commonring->cr_ctx = ctx;
  49 }
  50
  51
  52 void brcmf_commonring_config(struct brcmf_commonring *commonring, u16 depth,
  53                              u16 item_len, void *buf_addr)
  54 {
  55         commonring->depth = depth;
  56         commonring->item_len = item_len;
  57         commonring->buf_addr = buf_addr;
  58         if (!commonring->inited) {
  59                 spin_lock_init(&commonring->lock);
  60                 commonring->inited = true;
  61         }
  62         commonring->r_ptr = 0;
  63         if (commonring->cr_write_rptr)
  64                 commonring->cr_write_rptr(commonring->cr_ctx);
  65         commonring->w_ptr = 0;
  66         if (commonring->cr_write_wptr)
  67                 commonring->cr_write_wptr(commonring->cr_ctx);
  68         commonring->f_ptr = 0;
  69 }
  70
  71
  72 void brcmf_commonring_lock(struct brcmf_commonring *commonring)
  73                 __acquires(&commonring->lock)
  74 {
  75         unsigned long flags;
  76
  77         spin_lock_irqsave(&commonring->lock, flags);
  78         commonring->flags = flags;
  79 }
  80
  81
  82 void brcmf_commonring_unlock(struct brcmf_commonring *commonring)
  83                 __releases(&commonring->lock)
  84 {
  85         spin_unlock_irqrestore(&commonring->lock, commonring->flags);
  86 }
  87
  88
  89 bool brcmf_commonring_write_available(struct brcmf_commonring *commonring)
  90 {
  91         u16 available;
  92         bool retry = true;
  93
  94 again:
  95         if (commonring->r_ptr <= commonring->w_ptr)
  96                 available = commonring->depth - commonring->w_ptr +
  97                             commonring->r_ptr;
  98         else
  99                 available = commonring->r_ptr - commonring->w_ptr;
 100
 101         if (available > 1) {
 102                 if (!commonring->was_full)
 103                         return true;
 104                 if (available > commonring->depth / 8) {
 105                         commonring->was_full = false;
 106                         return true;
 107                 }
 108                 if (retry) {
 109                         if (commonring->cr_update_rptr)
 110                                 commonring->cr_update_rptr(commonring->cr_ctx);
 111                         retry = false;
 112                         goto again;
 113                 }
 114                 return false;
 115         }
 116
 117         if (retry) {
 118                 if (commonring->cr_update_rptr)
 119                         commonring->cr_update_rptr(commonring->cr_ctx);
 120                 retry = false;
 121                 goto again;
 122         }
 123
 124         commonring->was_full = true;
 125         return false;
 126 }
 127
 128
 129 void *brcmf_commonring_reserve_for_write(struct brcmf_commonring *commonring)
 130 {
 131         void *ret_ptr;
 132         u16 available;
 133         bool retry = true;
 134
 135 again:
 136         if (commonring->r_ptr <= commonring->w_ptr)
 137                 available = commonring->depth - commonring->w_ptr +
 138                             commonring->r_ptr;
 139         else
 140                 available = commonring->r_ptr - commonring->w_ptr;
 141
 142         if (available > 1) {
 143                 ret_ptr = commonring->buf_addr +
 144                           (commonring->w_ptr * commonring->item_len);
 145                 commonring->w_ptr++;
 146                 if (commonring->w_ptr == commonring->depth)
 147                         commonring->w_ptr = 0;
 148                 return ret_ptr;
 149         }
 150
 151         if (retry) {
 152                 if (commonring->cr_update_rptr)
 153                         commonring->cr_update_rptr(commonring->cr_ctx);
 154                 retry = false;
 155                 goto again;
 156         }
 157
 158         commonring->was_full = true;
 159         return NULL;
 160 }
 161
 162
 163 void *
 164 brcmf_commonring_reserve_for_write_multiple(struct brcmf_commonring *commonring,
 165                                             u16 n_items, u16 *alloced)
 166 {
 167         void *ret_ptr;
 168         u16 available;
 169         bool retry = true;
 170
 171 again:
 172         if (commonring->r_ptr <= commonring->w_ptr)
 173                 available = commonring->depth - commonring->w_ptr +
 174                             commonring->r_ptr;
 175         else
 176                 available = commonring->r_ptr - commonring->w_ptr;
 177
 178         if (available > 1) {
 179                 ret_ptr = commonring->buf_addr +
 180                           (commonring->w_ptr * commonring->item_len);
 181                 *alloced = min_t(u16, n_items, available - 1);
 182                 if (*alloced + commonring->w_ptr > commonring->depth)
 183                         *alloced = commonring->depth - commonring->w_ptr;
 184                 commonring->w_ptr += *alloced;
 185                 if (commonring->w_ptr == commonring->depth)
 186                         commonring->w_ptr = 0;
 187                 return ret_ptr;
 188         }
 189
 190         if (retry) {
 191                 if (commonring->cr_update_rptr)
 192                         commonring->cr_update_rptr(commonring->cr_ctx);
 193                 retry = false;
 194                 goto again;
 195         }
 196
 197         commonring->was_full = true;
 198         return NULL;
 199 }
 200
 201
 202 int brcmf_commonring_write_complete(struct brcmf_commonring *commonring)
 203 {
 204         void *address;
 205
 206         address = commonring->buf_addr;
 207         address += (commonring->f_ptr * commonring->item_len);
 208         if (commonring->f_ptr > commonring->w_ptr) {
 209                 brcmf_dma_flush(address,
 210                                 (commonring->depth - commonring->f_ptr) *
 211                                 commonring->item_len);
 212                 address = commonring->buf_addr;
 213                 commonring->f_ptr = 0;
 214         }
 215         brcmf_dma_flush(address, (commonring->w_ptr - commonring->f_ptr) *
 216                         commonring->item_len);
 217
 218         commonring->f_ptr = commonring->w_ptr;
 219
 220         if (commonring->cr_write_wptr)
 221                 commonring->cr_write_wptr(commonring->cr_ctx);
 222         if (commonring->cr_ring_bell)
 223                 return commonring->cr_ring_bell(commonring->cr_ctx);
 224
 225         return -EIO;
 226 }
 227
 228
 229 void brcmf_commonring_write_cancel(struct brcmf_commonring *commonring,
 230                                    u16 n_items)
 231 {
 232         if (commonring->w_ptr == 0)
 233                 commonring->w_ptr = commonring->depth - n_items;
 234         else
 235                 commonring->w_ptr -= n_items;
 236 }
 237
 238
 239 void *brcmf_commonring_get_read_ptr(struct brcmf_commonring *commonring,
 240                                     u16 *n_items)
 241 {
 242         void *ret_addr;
 243
 244         if (commonring->cr_update_wptr)
 245                 commonring->cr_update_wptr(commonring->cr_ctx);
 246
 247         *n_items = (commonring->w_ptr >= commonring->r_ptr) ?
 248                                 (commonring->w_ptr - commonring->r_ptr) :
 249                                 (commonring->depth - commonring->r_ptr);
 250
 251         if (*n_items == 0)
 252                 return NULL;
 253
 254         ret_addr = commonring->buf_addr +
 255                    (commonring->r_ptr * commonring->item_len);
 256
 257         commonring->r_ptr += *n_items;
 258         if (commonring->r_ptr == commonring->depth)
 259                 commonring->r_ptr = 0;
 260
 261         brcmf_dma_invalidate_cache(ret_addr, *n_ items * commonring->item_len);
 262
 263         return ret_addr;
 264 }
 265
 266
 267 int brcmf_commonring_read_complete(struct brcmf_commonring *commonring)
 268 {
 269         if (commonring->cr_write_rptr)
 270                 return commonring->cr_write_rptr(commonring->cr_ctx);
 271
 272         return -EIO;
 273 }