drivers/net/ethernet/intel/igbvf/mbx.c

   1 /*******************************************************************************
   2
   3   Intel(R) 82576 Virtual Function Linux driver
   4   Copyright(c) 2009 - 2012 Intel Corporation.
   5
   6   This program is free software; you can redistribute it and/or modify it
   7   under the terms and conditions of the GNU General Public License,
   8   version 2, as published by the Free Software Foundation.
   9
  10   This program is distributed in the hope it will be useful, but WITHOUT
  11   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13   more details.
  14
  15   You should have received a copy of the GNU General Public License along with
  16   this program; if not, see <http://www.gnu.org/licenses/>.
  17
  18   The full GNU General Public License is included in this distribution in
  19   the file called "COPYING".
  20
  21   Contact Information:
  22   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
  23   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  24
  25 *******************************************************************************/
  26
  27 #include "mbx.h"
  28
  29 /**
  30  *  e1000_poll_for_msg - Wait for message notification
  31  *  @hw: pointer to the HW structure
  32  *
  33  *  returns SUCCESS if it successfully received a message notification
  34  **/
  35 static s32 e1000_poll_for_msg(struct e1000_hw *hw)
  36 {
  37         struct e1000_mbx_info *mbx = &hw->mbx;
  38         int countdown = mbx->timeout;
  39
  40         if (!mbx->ops.check_for_msg)
  41                 goto out;
  42
  43         while (countdown && mbx->ops.check_for_msg(hw)) {
  44                 countdown--;
  45                 udelay(mbx->usec_delay);
  46         }
  47
  48         /* if we failed, all future posted messages fail until reset */
  49         if (!countdown)
  50                 mbx->timeout = 0;
  51 out:
  52         return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
  53 }
  54
  55 /**
  56  *  e1000_poll_for_ack - Wait for message acknowledgment
  57  *  @hw: pointer to the HW structure
  58  *
  59  *  returns SUCCESS if it successfully received a message acknowledgment
  60  **/
  61 static s32 e1000_poll_for_ack(struct e1000_hw *hw)
  62 {
  63         struct e1000_mbx_info *mbx = &hw->mbx;
  64         int countdown = mbx->timeout;
  65
  66         if (!mbx->ops.check_for_ack)
  67                 goto out;
  68
  69         while (countdown && mbx->ops.check_for_ack(hw)) {
  70                 countdown--;
  71                 udelay(mbx->usec_delay);
  72         }
  73
  74         /* if we failed, all future posted messages fail until reset */
  75         if (!countdown)
  76                 mbx->timeout = 0;
  77 out:
  78         return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
  79 }
  80
  81 /**
  82  *  e1000_read_posted_mbx - Wait for message notification and receive message
  83  *  @hw: pointer to the HW structure
  84  *  @msg: The message buffer
  85  *  @size: Length of buffer
  86  *
  87  *  returns SUCCESS if it successfully received a message notification and
  88  *  copied it into the receive buffer.
  89  **/
  90 static s32 e1000_read_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
  91 {
  92         struct e1000_mbx_info *mbx = &hw->mbx;
  93         s32 ret_val = -E1000_ERR_MBX;
  94
  95         if (!mbx->ops.read)
  96                 goto out;
  97
  98         ret_val = e1000_poll_for_msg(hw);
  99
 100         /* if ack received read message, otherwise we timed out */
 101         if (!ret_val)
 102                 ret_val = mbx->ops.read(hw, msg, size);
 103 out:
 104         return ret_val;
 105 }
 106
 107 /**
 108  *  e1000_write_posted_mbx - Write a message to the mailbox, wait for ack
 109  *  @hw: pointer to the HW structure
 110  *  @msg: The message buffer
 111  *  @size: Length of buffer
 112  *
 113  *  returns SUCCESS if it successfully copied message into the buffer and
 114  *  received an ack to that message within delay * timeout period
 115  **/
 116 static s32 e1000_write_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
 117 {
 118         struct e1000_mbx_info *mbx = &hw->mbx;
 119         s32 ret_val = -E1000_ERR_MBX;
 120
 121         /* exit if we either can't write or there isn't a defined timeout */
 122         if (!mbx->ops.write || !mbx->timeout)
 123                 goto out;
 124
 125         /* send msg*/
 126         ret_val = mbx->ops.write(hw, msg, size);
 127
 128         /* if msg sent wait until we receive an ack */
 129         if (!ret_val)
 130                 ret_val = e1000_poll_for_ack(hw);
 131 out:
 132         return ret_val;
 133 }
 134
 135 /**
 136  *  e1000_read_v2p_mailbox - read v2p mailbox
 137  *  @hw: pointer to the HW structure
 138  *
 139  *  This function is used to read the v2p mailbox without losing the read to
 140  *  clear status bits.
 141  **/
 142 static u32 e1000_read_v2p_mailbox(struct e1000_hw *hw)
 143 {
 144         u32 v2p_mailbox = er32(V2PMAILBOX(0));
 145
 146         v2p_mailbox |= hw->dev_spec.vf.v2p_mailbox;
 147         hw->dev_spec.vf.v2p_mailbox |= v2p_mailbox & E1000_V2PMAILBOX_R2C_BITS;
 148
 149         return v2p_mailbox;
 150 }
 151
 152 /**
 153  *  e1000_check_for_bit_vf - Determine if a status bit was set
 154  *  @hw: pointer to the HW structure
 155  *  @mask: bitmask for bits to be tested and cleared
 156  *
 157  *  This function is used to check for the read to clear bits within
 158  *  the V2P mailbox.
 159  **/
 160 static s32 e1000_check_for_bit_vf(struct e1000_hw *hw, u32 mask)
 161 {
 162         u32 v2p_mailbox = e1000_read_v2p_mailbox(hw);
 163         s32 ret_val = -E1000_ERR_MBX;
 164
 165         if (v2p_mailbox & mask)
 166                 ret_val = E1000_SUCCESS;
 167
 168         hw->dev_spec.vf.v2p_mailbox &= ~mask;
 169
 170         return ret_val;
 171 }
 172
 173 /**
 174  *  e1000_check_for_msg_vf - checks to see if the PF has sent mail
 175  *  @hw: pointer to the HW structure
 176  *
 177  *  returns SUCCESS if the PF has set the Status bit or else ERR_MBX
 178  **/
 179 static s32 e1000_check_for_msg_vf(struct e1000_hw *hw)
 180 {
 181         s32 ret_val = -E1000_ERR_MBX;
 182
 183         if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFSTS)) {
 184                 ret_val = E1000_SUCCESS;
 185                 hw->mbx.stats.reqs++;
 186         }
 187
 188         return ret_val;
 189 }
 190
 191 /**
 192  *  e1000_check_for_ack_vf - checks to see if the PF has ACK'd
 193  *  @hw: pointer to the HW structure
 194  *
 195  *  returns SUCCESS if the PF has set the ACK bit or else ERR_MBX
 196  **/
 197 static s32 e1000_check_for_ack_vf(struct e1000_hw *hw)
 198 {
 199         s32 ret_val = -E1000_ERR_MBX;
 200
 201         if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFACK)) {
 202                 ret_val = E1000_SUCCESS;
 203                 hw->mbx.stats.acks++;
 204         }
 205
 206         return ret_val;
 207 }
 208
 209 /**
 210  *  e1000_check_for_rst_vf - checks to see if the PF has reset
 211  *  @hw: pointer to the HW structure
 212  *
 213  *  returns true if the PF has set the reset done bit or else false
 214  **/
 215 static s32 e1000_check_for_rst_vf(struct e1000_hw *hw)
 216 {
 217         s32 ret_val = -E1000_ERR_MBX;
 218
 219         if (!e1000_check_for_bit_vf(hw, (E1000_V2PMAILBOX_RSTD |
 220                                          E1000_V2PMAILBOX_RSTI))) {
 221                 ret_val = E1000_SUCCESS;
 222                 hw->mbx.stats.rsts++;
 223         }
 224
 225         return ret_val;
 226 }
 227
 228 /**
 229  *  e1000_obtain_mbx_lock_vf - obtain mailbox lock
 230  *  @hw: pointer to the HW structure
 231  *
 232  *  return SUCCESS if we obtained the mailbox lock
 233  **/
 234 static s32 e1000_obtain_mbx_lock_vf(struct e1000_hw *hw)
 235 {
 236         s32 ret_val = -E1000_ERR_MBX;
 237
 238         /* Take ownership of the buffer */
 239         ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_VFU);
 240
 241         /* reserve mailbox for VF use */
 242         if (e1000_read_v2p_mailbox(hw) & E1000_V2PMAILBOX_VFU)
 243                 ret_val = E1000_SUCCESS;
 244
 245         return ret_val;
 246 }
 247
 248 /**
 249  *  e1000_write_mbx_vf - Write a message to the mailbox
 250  *  @hw: pointer to the HW structure
 251  *  @msg: The message buffer
 252  *  @size: Length of buffer
 253  *
 254  *  returns SUCCESS if it successfully copied message into the buffer
 255  **/
 256 static s32 e1000_write_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
 257 {
 258         s32 err;
 259         u16 i;
 260
 261         /* lock the mailbox to prevent pf/vf race condition */
 262         err = e1000_obtain_mbx_lock_vf(hw);
 263         if (err)
 264                 goto out_no_write;
 265
 266         /* flush any ack or msg as we are going to overwrite mailbox */
 267         e1000_check_for_ack_vf(hw);
 268         e1000_check_for_msg_vf(hw);
 269
 270         /* copy the caller specified message to the mailbox memory buffer */
 271         for (i = 0; i < size; i++)
 272                 array_ew32(VMBMEM(0), i, msg[i]);
 273
 274         /* update stats */
 275         hw->mbx.stats.msgs_tx++;
 276
 277         /* Drop VFU and interrupt the PF to tell it a message has been sent */
 278         ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_REQ);
 279
 280 out_no_write:
 281         return err;
 282 }
 283
 284 /**
 285  *  e1000_read_mbx_vf - Reads a message from the inbox intended for VF
 286  *  @hw: pointer to the HW structure
 287  *  @msg: The message buffer
 288  *  @size: Length of buffer
 289  *
 290  *  returns SUCCESS if it successfully read message from buffer
 291  **/
 292 static s32 e1000_read_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
 293 {
 294         s32 err;
 295         u16 i;
 296
 297         /* lock the mailbox to prevent pf/vf race condition */
 298         err = e1000_obtain_mbx_lock_vf(hw);
 299         if (err)
 300                 goto out_no_read;
 301
 302         /* copy the message from the mailbox memory buffer */
 303         for (i = 0; i < size; i++)
 304                 msg[i] = array_er32(VMBMEM(0), i);
 305
 306         /* Acknowledge receipt and release mailbox, then we're done */
 307         ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_ACK);
 308
 309         /* update stats */
 310         hw->mbx.stats.msgs_rx++;
 311
 312 out_no_read:
 313         return err;
 314 }
 315
 316 /**
 317  *  e1000_init_mbx_params_vf - set initial values for VF mailbox
 318  *  @hw: pointer to the HW structure
 319  *
 320  *  Initializes the hw->mbx struct to correct values for VF mailbox
 321  */
 322 s32 e1000_init_mbx_params_vf(struct e1000_hw *hw)
 323 {
 324         struct e1000_mbx_info *mbx = &hw->mbx;
 325
 326         /* start mailbox as timed out and let the reset_hw call set the timeout
 327          * value to being communications
 328          */
 329         mbx->timeout = 0;
 330         mbx->usec_delay = E1000_VF_MBX_INIT_DELAY;
 331
 332         mbx->size = E1000_VFMAILBOX_SIZE;
 333
 334         mbx->ops.read = e1000_read_mbx_vf;
 335         mbx->ops.write = e1000_write_mbx_vf;
 336         mbx->ops.read_posted = e1000_read_posted_mbx;
 337         mbx->ops.write_posted = e1000_write_posted_mbx;
 338         mbx->ops.check_for_msg = e1000_check_for_msg_vf;
 339         mbx->ops.check_for_ack = e1000_check_for_ack_vf;
 340         mbx->ops.check_for_rst = e1000_check_for_rst_vf;
 341
 342         mbx->stats.msgs_tx = 0;
 343         mbx->stats.msgs_rx = 0;
 344         mbx->stats.reqs = 0;
 345         mbx->stats.acks = 0;
 346         mbx->stats.rsts = 0;
 347
 348         return E1000_SUCCESS;
 349 }