1.\" 2.\" Copyright (c) 1999 Kenneth D. Merry. 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. The name of the author may not be used to endorse or promote products 11.\" derived from this software without specific prior written permission. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd January 3, 2008 28.Dt PCI 4 29.Os 30.Sh NAME 31.Nm pci 32.Nd generic PCI driver 33.Sh SYNOPSIS 34.Cd device pci 35.Sh DESCRIPTION 36The 37.Nm 38driver provides a way for userland programs to read and write 39.Tn PCI 40configuration registers. 41It also provides a way for userland programs to get a list of all 42.Tn PCI 43devices, or all 44.Tn PCI 45devices that match various patterns. 46.Pp 47Since the 48.Nm 49driver provides a write interface for 50.Tn PCI 51configuration registers, system administrators should exercise caution when 52granting access to the 53.Nm 54device. 55If used improperly, this driver can allow userland applications to 56crash a machine or cause data loss. 57.Pp 58The 59.Nm 60driver implements the 61.Tn PCI 62bus in the kernel. 63It enumerates any devices on the 64.Tn PCI 65bus and gives 66.Tn PCI 67client drivers the chance to attach to them. 68It assigns resources to children, when the BIOS does not. 69It takes care of routing interrupts when necessary. 70It reprobes the unattached 71.Tn PCI 72children when 73.Tn PCI 74client drivers are dynamically 75loaded at runtime. 76.Sh KERNEL CONFIGURATION 77The 78.Nm 79device is included in the kernel as described in the SYNOPSIS section. 80The 81.Nm 82driver cannot be built as a 83.Xr kld 4 . 84.Sh IOCTLS 85The following 86.Xr ioctl 2 87calls are supported by the 88.Nm 89driver. 90They are defined in the header file 91.In sys/pciio.h . 92.Bl -tag -width 012345678901234 93.It PCIOCGETCONF 94This 95.Xr ioctl 2 96takes a 97.Va pci_conf_io 98structure. 99It allows the user to retrieve information on all 100.Tn PCI 101devices in the system, or on 102.Tn PCI 103devices matching patterns supplied by the user. 104The call may set 105.Va errno 106to any value specified in either 107.Xr copyin 9 108or 109.Xr copyout 9 . 110The 111.Va pci_conf_io 112structure consists of a number of fields: 113.Bl -tag -width match_buf_len 114.It pat_buf_len 115The length, in bytes, of the buffer filled with user-supplied patterns. 116.It num_patterns 117The number of user-supplied patterns. 118.It patterns 119Pointer to a buffer filled with user-supplied patterns. 120.Va patterns 121is a pointer to 122.Va num_patterns 123.Va pci_match_conf 124structures. 125The 126.Va pci_match_conf 127structure consists of the following elements: 128.Bl -tag -width pd_vendor 129.It pc_sel 130.Tn PCI 131domain, bus, slot and function. 132.It pd_name 133.Tn PCI 134device driver name. 135.It pd_unit 136.Tn PCI 137device driver unit number. 138.It pc_vendor 139.Tn PCI 140vendor ID. 141.It pc_device 142.Tn PCI 143device ID. 144.It pc_class 145.Tn PCI 146device class. 147.It flags 148The flags describe which of the fields the kernel should match against. 149A device must match all specified fields in order to be returned. 150The match flags are enumerated in the 151.Va pci_getconf_flags 152structure. 153Hopefully the flag values are obvious enough that they do not need to 154described in detail. 155.El 156.It match_buf_len 157Length of the 158.Va matches 159buffer allocated by the user to hold the results of the 160.Dv PCIOCGETCONF 161query. 162.It num_matches 163Number of matches returned by the kernel. 164.It matches 165Buffer containing matching devices returned by the kernel. 166The items in this buffer are of type 167.Va pci_conf , 168which consists of the following items: 169.Bl -tag -width pc_subvendor 170.It pc_sel 171.Tn PCI 172domain, bus, slot and function. 173.It pc_hdr 174.Tn PCI 175header type. 176.It pc_subvendor 177.Tn PCI 178subvendor ID. 179.It pc_subdevice 180.Tn PCI 181subdevice ID. 182.It pc_vendor 183.Tn PCI 184vendor ID. 185.It pc_device 186.Tn PCI 187device ID. 188.It pc_class 189.Tn PCI 190device class. 191.It pc_subclass 192.Tn PCI 193device subclass. 194.It pc_progif 195.Tn PCI 196device programming interface. 197.It pc_revid 198.Tn PCI 199revision ID. 200.It pd_name 201Driver name. 202.It pd_unit 203Driver unit number. 204.El 205.It offset 206The offset is passed in by the user to tell the kernel where it should 207start traversing the device list. 208The value passed out by the kernel 209points to the record immediately after the last one returned. 210The user may 211pass the value returned by the kernel in subsequent calls to the 212.Dv PCIOCGETCONF 213ioctl. 214If the user does not intend to use the offset, it must be set to zero. 215.It generation 216.Tn PCI 217configuration generation. 218This value only needs to be set if the offset is set. 219The kernel will compare the current generation number of its internal 220device list to the generation passed in by the user to determine whether 221its device list has changed since the user last called the 222.Dv PCIOCGETCONF 223ioctl. 224If the device list has changed, a status of 225.Va PCI_GETCONF_LIST_CHANGED 226will be passed back. 227.It status 228The status tells the user the disposition of his request for a device list. 229The possible status values are: 230.Bl -ohang 231.It PCI_GETCONF_LAST_DEVICE 232This means that there are no more devices in the PCI device list after the 233ones returned in the 234.Va matches 235buffer. 236.It PCI_GETCONF_LIST_CHANGED 237This status tells the user that the 238.Tn PCI 239device list has changed since his last call to the 240.Dv PCIOCGETCONF 241ioctl and he must reset the 242.Va offset 243and 244.Va generation 245to zero to start over at the beginning of the list. 246.It PCI_GETCONF_MORE_DEVS 247This tells the user that his buffer was not large enough to hold all of the 248remaining devices in the device list that possibly match his criteria. 249It is possible for this status to be returned, even when none of the remaining 250devices in the list would match the user's criteria. 251.It PCI_GETCONF_ERROR 252This indicates a general error while servicing the user's request. 253If the 254.Va pat_buf_len 255is not equal to 256.Va num_patterns 257times 258.Fn sizeof "struct pci_match_conf" , 259.Va errno 260will be set to 261.Er EINVAL . 262.El 263.El 264.It PCIOCREAD 265This 266.Xr ioctl 2 267reads the 268.Tn PCI 269configuration registers specified by the passed-in 270.Va pci_io 271structure. 272The 273.Va pci_io 274structure consists of the following fields: 275.Bl -tag -width pi_width 276.It pi_sel 277A 278.Va pcisel 279structure which specifies the domain, bus, slot and function the user would 280like to query. 281If the specific bus is not found, errno will be set to ENODEV and -1 returned 282from the ioctl. 283.It pi_reg 284The 285.Tn PCI 286configuration register the user would like to access. 287.It pi_width 288The width, in bytes, of the data the user would like to read. 289This value 290may be either 1, 2, or 4. 2913-byte reads and reads larger than 4 bytes are 292not supported. 293If an invalid width is passed, errno will be set to EINVAL. 294.It pi_data 295The data returned by the kernel. 296.El 297.It PCIOCWRITE 298This 299.Xr ioctl 2 300allows users to write to the 301.Tn PCI 302specified in the passed-in 303.Va pci_io 304structure. 305The 306.Va pci_io 307structure is described above. 308The limitations on data width described for 309reading registers, above, also apply to writing 310.Tn PCI 311configuration registers. 312.El 313.Sh FILES 314.Bl -tag -width /dev/pci -compact 315.It Pa /dev/pci 316Character device for the 317.Nm 318driver. 319.El 320.Sh SEE ALSO 321.Xr pciconf 8 322.Sh HISTORY 323The 324.Nm 325driver (not the kernel's 326.Tn PCI 327support code) first appeared in 328.Fx 2.2 , 329and was written by Stefan Esser and Garrett Wollman. 330Support for device listing and matching was re-implemented by 331Kenneth Merry, and first appeared in 332.Fx 3.0 . 333.Sh AUTHORS 334.An Kenneth Merry Aq Mt ken@FreeBSD.org 335.Sh BUGS 336It is not possible for users to specify an accurate offset into the device 337list without calling the 338.Dv PCIOCGETCONF 339at least once, since they have no way of knowing the current generation 340number otherwise. 341This probably is not a serious problem, though, since 342users can easily narrow their search by specifying a pattern or patterns 343for the kernel to match against. 344