drivers/net/igbvf/mbx.c

   1 /*******************************************************************************
   2
   3   Intel(R) 82576 Virtual Function Linux driver
   4   Copyright(c) 2009 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, write to the Free Software Foundation, Inc.,
  17   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18
  19   The full GNU General Public License is included in this distribution in
  20   the file called "COPYING".
  21
  22   Contact Information:
  23   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
  24   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  25
  26 *******************************************************************************/
  27
  28 #include "mbx.h"
  29
  30 /**
  31  *  e1000_poll_for_msg - Wait for message notification
  32  *  @hw: pointer to the HW structure
  33  *
  34  *  returns SUCCESS if it successfully received a message notification
  35  **/
  36 static s32 e1000_poll_for_msg(struct e1000_hw *hw)
  37 {
  38         struct e1000_mbx_info *mbx = &hw->mbx;
  39         int countdown = mbx->timeout;
  40
  41         if (!mbx->ops.check_for_msg)
  42                 goto out;
  43
  44         while (countdown && mbx->ops.check_for_msg(hw)) {
  45                 countdown--;
  46                 udelay(mbx->usec_delay);
  47         }
  48
  49         /* if we failed, all future posted messages fail until reset */
  50         if (!countdown)
  51                 mbx->timeout = 0;
  52 out:
  53         return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
  54 }
  55
  56 /**
  57  *  e1000_poll_for_ack - Wait for message acknowledgement
  58  *  @hw: pointer to the HW structure
  59  *
  60  *  returns SUCCESS if it successfully received a message acknowledgement
  61  **/
  62 static s32 e1000_poll_for_ack(struct e1000_hw *hw)
  63 {
  64         struct e1000_mbx_info *mbx = &hw->mbx;
  65         int countdown = mbx->timeout;
  66
  67         if (!mbx->ops.check_for_ack)
  68                 goto out;
  69
  70         while (countdown && mbx->ops.check_for_ack(hw)) {
  71                 countdown--;
  72                 udelay(mbx->usec_delay);
  73         }
  74
  75         /* if we failed, all future posted messages fail until reset */
  76         if (!countdown)
  77                 mbx->timeout = 0;
  78 out:
  79         return countdown ? E1000_SUCCESS : -E1000_ERR_MBX;
  80 }
  81
  82 /**
  83  *  e1000_read_posted_mbx - Wait for message notification and receive message
  84  *  @hw: pointer to the HW structure
  85  *  @msg: The message buffer
  86  *  @size: Length of buffer
  87  *
  88  *  returns SUCCESS if it successfully received a message notification and
  89  *  copied it into the receive buffer.
  90  **/
  91 static s32 e1000_read_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
  92 {
  93         struct e1000_mbx_info *mbx = &hw->mbx;
  94         s32 ret_val = -E1000_ERR_MBX;
  95
  96         if (!mbx->ops.read)
  97                 goto out;
  98
  99         ret_val = e1000_poll_for_msg(hw);
 100
 101         /* if ack received read message, otherwise we timed out */
 102         if (!ret_val)
 103                 ret_val = mbx->ops.read(hw, msg, size);
 104 out:
 105         return ret_val;
 106 }
 107
 108 /**
 109  *  e1000_write_posted_mbx - Write a message to the mailbox, wait for ack
 110  *  @hw: pointer to the HW structure
 111  *  @msg: The message buffer
 112  *  @size: Length of buffer
 113  *
 114  *  returns SUCCESS if it successfully copied message into the buffer and
 115  *  received an ack to that message within delay * timeout period
 116  **/
 117 static s32 e1000_write_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size)
 118 {
 119         struct e1000_mbx_info *mbx = &hw->mbx;
 120         s32 ret_val = -E1000_ERR_MBX;
 121
 122         /* exit if we either can't write or there isn't a defined timeout */
 123         if (!mbx->ops.write || !mbx->timeout)
 124                 goto out;
 125
 126         /* send msg*/
 127         ret_val = mbx->ops.write(hw, msg, size);
 128
 129         /* if msg sent wait until we receive an ack */
 130         if (!ret_val)
 131                 ret_val = e1000_poll_for_ack(hw);
 132 out:
 133         return ret_val;
 134 }
 135
 136 /**
 137  *  e1000_read_v2p_mailbox - read v2p mailbox
 138  *  @hw: pointer to the HW structure
 139  *
 140  *  This function is used to read the v2p mailbox without losing the read to
 141  *  clear status bits.
 142  **/
 143 static u32 e1000_read_v2p_mailbox(struct e1000_hw *hw)
 144 {
 145         u32 v2p_mailbox = er32(V2PMAILBOX(0));
 146
 147         v2p_mailbox |= hw->dev_spec.vf.v2p_mailbox;
 148         hw->dev_spec.vf.v2p_mailbox |= v2p_mailbox & E1000_V2PMAILBOX_R2C_BITS;
 149
 150         return v2p_mailbox;
 151 }
 152
 153 /**
 154  *  e1000_check_for_bit_vf - Determine if a status bit was set
 155  *  @hw: pointer to the HW structure
 156  *  @mask: bitmask for bits to be tested and cleared
 157  *
 158  *  This function is used to check for the read to clear bits within
 159  *  the V2P mailbox.
 160  **/
 161 static s32 e1000_check_for_bit_vf(struct e1000_hw *hw, u32 mask)
 162 {
 163         u32 v2p_mailbox = e1000_read_v2p_mailbox(hw);
 164         s32 ret_val = -E1000_ERR_MBX;
 165
 166         if (v2p_mailbox & mask)
 167                 ret_val = E1000_SUCCESS;
 168
 169         hw->dev_spec.vf.v2p_mailbox &= ~mask;
 170
 171         return ret_val;
 172 }
 173
 174 /**
 175  *  e1000_check_for_msg_vf - checks to see if the PF has sent mail
 176  *  @hw: pointer to the HW structure
 177  *
 178  *  returns SUCCESS if the PF has set the Status bit or else ERR_MBX
 179  **/
 180 static s32 e1000_check_for_msg_vf(struct e1000_hw *hw)
 181 {
 182         s32 ret_val = -E1000_ERR_MBX;
 183
 184         if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFSTS)) {
 185                 ret_val = E1000_SUCCESS;
 186                 hw->mbx.stats.reqs++;
 187         }
 188
 189         return ret_val;
 190 }
 191
 192 /**
 193  *  e1000_check_for_ack_vf - checks to see if the PF has ACK'd
 194  *  @hw: pointer to the HW structure
 195  *
 196  *  returns SUCCESS if the PF has set the ACK bit or else ERR_MBX
 197  **/
 198 static s32 e1000_check_for_ack_vf(struct e1000_hw *hw)
 199 {
 200         s32 ret_val = -E1000_ERR_MBX;
 201
 202         if (!e1000_check_for_bit_vf(hw, E1000_V2PMAILBOX_PFACK)) {
 203                 ret_val = E1000_SUCCESS;
 204                 hw->mbx.stats.acks++;
 205         }
 206
 207         return ret_val;
 208 }
 209
 210 /**
 211  *  e1000_check_for_rst_vf - checks to see if the PF has reset
 212  *  @hw: pointer to the HW structure
 213  *
 214  *  returns true if the PF has set the reset done bit or else false
 215  **/
 216 static s32 e1000_check_for_rst_vf(struct e1000_hw *hw)
 217 {
 218         s32 ret_val = -E1000_ERR_MBX;
 219
 220         if (!e1000_check_for_bit_vf(hw, (E1000_V2PMAILBOX_RSTD |
 221                                          E1000_V2PMAILBOX_RSTI))) {
 222                 ret_val = E1000_SUCCESS;
 223                 hw->mbx.stats.rsts++;
 224         }
 225
 226         return ret_val;
 227 }
 228
 229 /**
 230  *  e1000_obtain_mbx_lock_vf - obtain mailbox lock
 231  *  @hw: pointer to the HW structure
 232  *
 233  *  return SUCCESS if we obtained the mailbox lock
 234  **/
 235 static s32 e1000_obtain_mbx_lock_vf(struct e1000_hw *hw)
 236 {
 237         s32 ret_val = -E1000_ERR_MBX;
 238
 239         /* Take ownership of the buffer */
 240         ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_VFU);
 241
 242         /* reserve mailbox for vf use */
 243         if (e1000_read_v2p_mailbox(hw) & E1000_V2PMAILBOX_VFU)
 244                 ret_val = E1000_SUCCESS;
 245
 246         return ret_val;
 247 }
 248
 249 /**
 250  *  e1000_write_mbx_vf - Write a message to the mailbox
 251  *  @hw: pointer to the HW structure
 252  *  @msg: The message buffer
 253  *  @size: Length of buffer
 254  *
 255  *  returns SUCCESS if it successfully copied message into the buffer
 256  **/
 257 static s32 e1000_write_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
 258 {
 259         s32 err;
 260         u16 i;
 261
 262         /* lock the mailbox to prevent pf/vf race condition */
 263         err = e1000_obtain_mbx_lock_vf(hw);
 264         if (err)
 265                 goto out_no_write;
 266
 267         /* flush any ack or msg as we are going to overwrite mailbox */
 268         e1000_check_for_ack_vf(hw);
 269         e1000_check_for_msg_vf(hw);
 270
 271         /* copy the caller specified message to the mailbox memory buffer */
 272         for (i = 0; i < size; i++)
 273                 array_ew32(VMBMEM(0), i, msg[i]);
 274
 275         /* update stats */
 276         hw->mbx.stats.msgs_tx++;
 277
 278         /* Drop VFU and interrupt the PF to tell it a message has been sent */
 279         ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_REQ);
 280
 281 out_no_write:
 282         return err;
 283 }
 284
 285 /**
 286  *  e1000_read_mbx_vf - Reads a message from the inbox intended for vf
 287  *  @hw: pointer to the HW structure
 288  *  @msg: The message buffer
 289  *  @size: Length of buffer
 290  *
 291  *  returns SUCCESS if it successfuly read message from buffer
 292  **/
 293 static s32 e1000_read_mbx_vf(struct e1000_hw *hw, u32 *msg, u16 size)
 294 {
 295         s32 err;
 296         u16 i;
 297
 298         /* lock the mailbox to prevent pf/vf race condition */
 299         err = e1000_obtain_mbx_lock_vf(hw);
 300         if (err)
 301                 goto out_no_read;
 302
 303         /* copy the message from the mailbox memory buffer */
 304         for (i = 0; i < size; i++)
 305                 msg[i] = array_er32(VMBMEM(0), i);
 306
 307         /* Acknowledge receipt and release mailbox, then we're done */
 308         ew32(V2PMAILBOX(0), E1000_V2PMAILBOX_ACK);
 309
 310         /* update stats */
 311         hw->mbx.stats.msgs_rx++;
 312
 313 out_no_read:
 314         return err;
 315 }
 316
 317 /**
 318  *  e1000_init_mbx_params_vf - set initial values for vf mailbox
 319  *  @hw: pointer to the HW structure
 320  *
 321  *  Initializes the hw->mbx struct to correct values for vf mailbox
 322  */
 323 s32 e1000_init_mbx_params_vf(struct e1000_hw *hw)
 324 {
 325         struct e1000_mbx_info *mbx = &hw->mbx;
 326
 327         /* start mailbox as timed out and let the reset_hw call set the timeout
 328          * value to being communications */
 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 }
 350