1 .\" Copyright (c) 2001-2003, Intel Corporation
2 .\" All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions are met:
7 .\" 1. Redistributions of source code must retain the above copyright notice,
8 .\" this list of conditions and the following disclaimer.
10 .\" 2. Redistributions in binary form must reproduce the above copyright
11 .\" notice, this list of conditions and the following disclaimer in the
12 .\" documentation and/or other materials provided with the distribution.
14 .\" 3. Neither the name of the Intel Corporation nor the names of its
15 .\" contributors may be used to endorse or promote products derived from
16 .\" this software without specific prior written permission.
18 .\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 .\" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22 .\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 .\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 .\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 .\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 .\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 .\" POSSIBILITY OF SUCH DAMAGE.
30 .\" * Other names and brands may be claimed as the property of others.
32 .\" $FreeBSD: src/share/man/man4/em.4,v 1.30 2008/10/06 21:55:53 simon Exp $
40 .Nd "Intel(R) PRO/1000 Gigabit Ethernet adapter driver"
42 To compile this driver into the kernel,
43 place the following lines in your
44 kernel configuration file:
45 .Bd -ragged -offset indent
47 .Cd "device em # for em(4)"
48 .Cd "device emx # for emx(4)"
51 Alternatively, to load the driver as a
52 module at boot time, place the following lines in
54 .Bd -literal -offset indent
56 if_em_load="YES" # for em(4)
57 if_emx_load="YES" # for emx(4)
62 driver provides support for PCI Gigabit Ethernet adapters based on
63 the Intel 82540, 82541ER, 82541PI, 82542, 82543, 82544, 82545, 82546,
64 82546EB, 82546GB, 82547, 82571, 81572, 82573, and 82574 Ethernet
66 The driver supports Transmit/Receive checksum offload
67 and Jumbo Frames on all but 82542-based adapters.
68 Furthermore it supports TCP segmentation offload (TSO) on adapters
69 based on the 82571, 82572, 82573 and 82574 controller chips.
70 .\"For further hardware information, see the
72 .\"included with the driver.
78 driver for 82571, 82572, 82573, and 82574 Ethernet controller chips that
79 additionally supports Receive Side Scaling (RSS, 2 reception queues).
83 driver will try enabling 2 reception queues
84 if there are multiple CPUs on the system.
88 driver could be configured to enable 2 transmission queues.
92 driver only enables 1 transmission queue,
93 since enabling 2 transmission queues will require setting up context
94 descriptor for every packets requiring hardware transmission offloading,
95 which hurts tiny packet transmission performance.
97 if the workload is mainly bulk data
98 or hardware transmission offloading is rarely required,
99 extra transmission queue could be enabled to reduce contention on
101 2 transmission queues will only be used when
103 is enabled on the device.
104 If multiple transmission queues are used,
105 the round-robin arbitration is performed among the transmission queues.
106 It should be noted that
107 if both TSO and multiple transmission queues are used,
108 the round-robin arbitration between transmission queues is done
109 at the TSO packet boundary.
111 .\"For questions related to hardware requirements,
112 .\"refer to the documentation supplied with your Intel PRO/1000 adapter.
113 .\"All hardware requirements listed apply to use with
116 Support for Jumbo Frames is provided via the interface MTU setting.
117 Selecting an MTU larger than 1500 bytes with the
119 utility configures the adapter to receive and transmit Jumbo Frames.
120 The maximum MTU size for Jumbo Frames is 16114.
122 This driver version supports VLANs.
127 drivers support the following media types:
128 .Bl -tag -width ".Cm 10baseT/UTP"
130 Enables auto-negotiation for speed and duplex.
132 Sets 10Mbps operation.
139 Sets 100Mbps operation.
146 Sets 1000Mbps operation.
149 mode is supported at this speed.
151 Sets 1000Mbps operation.
154 mode is supported at this speed.
161 drivers support the following media options:
162 .Bl -tag -width ".Cm full-duplex"
164 Forces full-duplex operation
166 Forces half-duplex operation.
175 is not specified, the driver defaults to
178 For more information on configuring this device, see
190 driver supports Gigabit Ethernet adapters based on the Intel
191 82540, 82541ER, 82541PI, 82542, 82543, 82544, 82545, 82546, 82546EB,
192 82546GB, 82547, 82571, 82572, 82573, 82574, I217 and I218
197 Intel 82540EM Gigabit Ethernet Controller
199 Intel 82540EP Gigabit Ethernet Controller
201 Intel 82543GC Gigabit Ethernet Controller
203 Intel 82544 Gigabit Ethernet Controller
205 Intel 82544EI Gigabit Ethernet Controller
207 Intel 82545GM Gigabit Ethernet Controller
209 Intel 82546EB Gigabit Ethernet Controller
211 Intel 82547EI Gigabit Ethernet Controller
213 Intel 82547GI Gigabit Ethernet Controller
215 Intel 82567 Gigabit Ethernet Controller
217 Intel 82571EB Gigabit Ethernet Controller
219 Intel 82572EI Gigabit Ethernet Controller
221 Intel 82573E Gigabit Ethernet Controller
223 Intel 82573L Gigabit Ethernet Controller
225 Intel 82573V Gigabit Ethernet Controller
227 Intel 82574 Gigabit Ethernet Controller
229 Intel 82578 Gigabit Ethernet PHY
231 Intel 82579 Gigabit Ethernet Controller
233 Intel Ethernet Connection I217-LM
235 Intel Ethernet Connection I217-V
237 Intel Ethernet Connection I218-LM
239 Intel Ethernet Connection I218-V
241 Intel Gigabit CT Desktop Adapter
243 Intel PRO/1000 F Server Adapter
245 Intel PRO/1000 GT Quad Port Server Adapter
247 Intel PRO/1000 MF Dual Port Server Adapter
249 Intel PRO/1000 MF Server Adapter
251 Intel PRO/1000 MF Server Adapter (LX)
253 Intel PRO/1000 MT Dual Port Server Adapter
255 Intel PRO/1000 MT Quad Port Server Adapter
257 Intel PRO/1000 MT Server Adapter
259 Intel PRO/1000 PF Dual Port Server Adapter
261 Intel PRO/1000 PF Quad Port Server Adapter
263 Intel PRO/1000 PF Server Adapter
265 Intel PRO/1000 PT Dual Port Server Adapter
267 Intel PRO/1000 PT Quad Port Low Profile Server Adapter
269 Intel PRO/1000 PT Quad Port Server Adapter
271 Intel PRO/1000 PT Server Adapter
273 Intel PRO/1000 T Server Adapter
275 Intel PRO/1000 XT Low Profile Server Adapter
277 Intel PRO/1000 XT Server Adapter
282 driver supports Gigabit Ethernet adapters based on the Intel
283 82571, 82572, 82573, and 82574 controller chips.
285 Tunables can be set at the
287 prompt before booting the kernel or stored in
290 is the device unit number.
291 .Bl -tag -width "hw.em.int_throttle_ceil"
292 .It Va hw.em.int_throttle_ceil
293 Hardware interrupt throttling rate.
294 The default value is 6000Hz.
295 This tunable also applies to
298 has a per device tunable
299 .Va hw.emxY.int_throttle_ceil ,
300 which serves the same purpose.
302 Number of receive descriptors allocated by the driver.
303 The default value is 512.
304 The 82542 and 82543-based adapters can handle up to 256 descriptors,
305 while others can have up to 4096.
306 This tunable also applies to
309 has a per device tunable
311 which serves the same purpose.
313 Number of transmit descriptors allocated by the driver.
314 The default value is 512.
315 The 82542 and 82543-based adapters can handle up to 256 descriptors,
316 while others can have up to 4096.
317 This tunable also applies to
320 has a per device tunable
322 which serves the same purpose.
323 .It Va hw.em.msi.enable Va hw.emY.msi.enable
324 By default, the driver will use MSI if it is supported.
325 This behavior can be turned off by setting these tunable to 0.
326 These tunables also applies to
328 .It Va hw.emY.msi.cpu
330 it specifies the MSI's target CPU.
331 This tunable also applies to
333 .It Va hw.emY.irq.unshared
334 If legacy interrupt is used,
336 the driver assumes the interrupt could be shared.
337 Setting this tunable to 1 allows the driver to
338 perform certain optimization based on the knowledge
339 that the interrupt is not shared.
340 These tunables also applies to
342 .It Va hw.emx.rxr Va hw.emxY.rxr
343 This tunable specifies the number of reception queues could be enabled.
344 Maximum allowed value for these tunables is 2.
345 Setting these tunables to 0 allows the driver to enable reception
346 queues based on the number of CPUs.
347 The default value is 0.
348 .It Va hw.emx.txr Va hw.emxY.txr
349 These tunables only take effect on 82571 and 82572.
350 This tunable specifies the number of transmission queues could be enabled.
351 Maximum allowed value for these tunables is 2.
352 Setting these tunables to 0 allows the driver to enable transmission
353 queues based on the number of CPUs.
354 The default value is 1.
355 .It Va hw.emxY.npoll.rxoff
356 This tunable specifies the leading target CPU for reception queues
359 The value specificed must be aligned to the number of reception queues enabled
360 and must be less than the power of 2 number of CPUs.
361 .It Va hw.emxY.npoll.rxoff
362 This tunable specifies the leading target CPU for transmission queues
365 The value specificed must be aligned to the number of transmission queues
367 and must be less than the power of 2 number of CPUs.
370 A number of per-interface variables are implemented in the
377 .Bl -tag -width "int_throttle_ceil"
379 Number of reception descriptors enabled (read-only).
386 Number of transmission descriptors enabled (read-only).
392 .It Va int_throttle_ceil
394 .Va hw.em.int_throttle_ceil .
396 This value controls how many transmit descriptors should be consumed
397 by the hardware before the hardware generates a transmit interrupt.
398 The default value is 1/16 of the number of transmit descriptors.
401 is not used on the hardware and
402 the major part of the transmitted data are bulk data,
403 this value could safely be set to 1/2 of the number of transmit descriptors.
405 The number of transmission descriptors should be setup
406 before the hardware register is written.
407 Setting this value too high will have negative effect
408 on transmission timeliness.
409 Setting this value too low will hurt overall transmission due to
410 the frequent hardware register writing.
413 Number of reception queues enableed (read-only).
414 This sysctl only applies to
422 Number of transmission queues that cound be enableed (read-only).
423 This sysctl only applies to
431 Number of transmission queues being used (read-only).
432 This sysctl only applies to
436 .Va hw.emxY.npoll.rxoff .
437 The set value will take effect the next time
439 is enabled on the device.
440 This sysctl only applies to
444 .Va hw.emxY.npoll.txoff .
445 The set value will take effect the next time
447 is enabled on the device.
448 This sysctl only applies to
452 .\"For general information and support,
453 .\"go to the Intel support website at:
454 .\".Pa http://support.intel.com .
456 .\"If an issue is identified with the released source code on the supported kernel
457 .\"with a supported adapter, email the specific information related to the
459 .\".Aq Mt freebsdnic@mailbox.intel.com .
471 device driver first appeared in
475 driver first appeared in
481 driver was written by
482 .An Intel Corporation Aq Mt freebsdnic@mailbox.intel.com .
486 driver was written by