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 October 24, 1999 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. It also provides a way for userland programs to 41get 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. If used improperly, this driver can allow userland applications to 55crash a machine or cause data loss. 56.Sh KERNEL CONFIGURATION 57It is only necessary to specify one 58.Nm 59controller in the kernel. Additional 60.Tn PCI 61busses are handled automatically as they are encountered. 62.Sh IOCTLS 63The following 64.Xr ioctl 2 65calls are supported by the 66.Nm 67driver. They are defined in the header file 68.Aq Pa sys/pciio.h . 69.Bl -tag -width 012345678901234 70.Pp 71.It PCIOCGETCONF 72This 73.Xr ioctl 2 74takes a 75.Va pci_conf_io 76structure. It allows the user to retrieve information on all 77.Tn PCI 78devices in the system, or on 79.Tn PCI 80devices matching patterns supplied by the user. The call may set 81.Va errno 82to any value specified in either 83.Xr copyin 9 84or 85.Xr copyout 9 . 86The 87.Va pci_conf_io 88structure consists of a number of fields: 89.Bl -tag -width match_buf_len 90.It pat_buf_len 91The length, in bytes, of the buffer filled with user-supplied patterns. 92.It num_patterns 93The number of user-supplied patterns. 94.It patterns 95Pointer to a buffer filled with user-supplied patterns. 96.Va patterns 97is a pointer to 98.Va num_patterns 99.Va pci_match_conf 100structures. The 101.Va pci_match_conf 102structure consists of the following elements: 103.Bl -tag -width pd_vendor 104.It pc_sel 105.Tn PCI 106bus, slot and function. 107.It pd_name 108.Tn PCI 109device driver name. 110.It pd_unit 111.Tn PCI 112device driver unit number. 113.It pc_vendor 114.Tn PCI 115vendor ID. 116.It pc_device 117.Tn PCI 118device ID. 119.It pc_class 120.Tn PCI 121device class. 122.It flags 123The flags describe which of the fields the kernel should match against. 124A device must match all specified fields in order to be returned. The 125match flags are enumerated in the 126.Va pci_getconf_flags 127structure. 128Hopefully the flag values are obvious enough that they don't need to 129described in detail. 130.El 131.It match_buf_len 132Length of the 133.Va matches 134buffer allocated by the user to hold the results of the 135.Dv PCIOCGETCONF 136query. 137.It num_matches 138Number of matches returned by the kernel. 139.It matches 140Buffer containing matching devices returned by the kernel. The items in 141this buffer are of type 142.Va pci_conf , 143which consists of the following items: 144.Bl -tag -width pc_subvendor 145.It pc_sel 146.Tn PCI 147bus, slot and function. 148.It pc_hdr 149.Tn PCI 150header type. 151.It pc_subvendor 152.Tn PCI 153subvendor ID. 154.It pc_subdevice 155.Tn PCI 156subdevice ID. 157.It pc_vendor 158.Tn PCI 159vendor ID. 160.It pc_device 161.Tn PCI 162device ID. 163.It pc_class 164.Tn PCI 165device class. 166.It pc_subclass 167.Tn PCI 168device subclass. 169.It pc_progif 170.Tn PCI 171device programming interface. 172.It pc_revid 173.Tn PCI 174revision ID. 175.It pd_name 176Driver name. 177.It pd_unit 178Driver unit number. 179.El 180.It offset 181The offset is passed in by the user to tell the kernel where it should 182start traversing the device list. The value passed out by the kernel 183points to the record immediately after the last one returned. The user may 184pass the value returned by the kernel in subsequent calls to the 185.Dv PCIOCGETCONF 186ioctl. If the user does not intend to use the offset, it must be set to 187zero. 188.It generation 189.Tn PCI 190configuration generation. This value only needs to be set if the offset is 191set. The kernel will compare the current generation number of its internal 192device list to the generation passed in by the user to determine whether 193its device list has changed since the user last called the 194.Dv PCIOCGETCONF 195ioctl. If the device list has changed, a status of 196.Va PCI_GETCONF_LIST_CHANGED 197will be passed back. 198.It status 199The status tells the user the disposition of his request for a device list. 200The possible status values are: 201.Bl -ohang 202.It PCI_GETCONF_LAST_DEVICE 203This means that there are no more devices in the PCI device list after the 204ones returned in the 205.Va matches 206buffer. 207.It PCI_GETCONF_LIST_CHANGED 208This status tells the user that the 209.Tn PCI 210device list has changed since his last call to the 211.Dv PCIOCGETCONF 212ioctl and he must reset the 213.Va offset 214and 215.Va generation 216to zero to start over at the beginning of the list. 217.It PCI_GETCONF_MORE_DEVS 218This tells the user that his buffer was not large enough to hold all of the 219remaining devices in the device list that possibly match his criteria. It 220is possible for this status to be returned, even when none of the remaining 221devices in the list would match the user's criteria. 222.It PCI_GETCONF_ERROR 223This indicates a general error while servicing the user's request. If the 224.Va pat_buf_len 225is not equal to 226.Va num_patterns 227times 228.Va sizeof(struct pci_match_conf) , errno 229will be set to EINVAL. 230.El 231.El 232.It PCIOCREAD 233This 234.Xr ioctl 2 235reads the 236.Tn PCI 237configuration registers specified by the passed-in 238.Va pci_io 239structure. The 240.Va pci_io 241structure consists of the following fields: 242.Bl -tag -width pi_width 243.It pi_sel 244A 245.Va pcisel 246structure which specifies the bus, slot and function the user would like to 247query. If the specific bus is not found, errno will be set to ENODEV and -1 returned from the ioctl. 248.It pi_reg 249The 250.Tn PCI 251configuration register the user would like to access. 252.It pi_width 253The width, in bytes, of the data the user would like to read. This value 254may be either 1, 2, or 4. 3-byte reads and reads larger than 4 bytes are 255not supported. If an invalid width is passed, errno will be set to EINVAL. 256.It pi_data 257The data returned by the kernel. 258.El 259.It PCIOCWRITE 260This 261.Xr ioctl 2 262allows users to write to the 263.Tn PCI 264specified in the passed-in 265.Va pci_io 266structure. The 267.Va pci_io 268structure is described above. The limitations on data width described for 269reading registers, above, also apply to writing 270.Tn PCI 271configuration registers. 272.El 273.Sh FILES 274.Bl -tag -width /dev/pci -compact 275.It Pa /dev/pci 276Character device for the 277.Nm 278driver. 279.El 280.Sh DIAGNOSTICS 281None. 282.Sh SEE ALSO 283.Xr pciconf 8 284.Sh HISTORY 285The 286.Nm 287driver (not the kernel's 288.Tn PCI 289support code) first appeared in 290.Fx 2.2 , 291and was written by Stefan Esser and Garrett Wollman. 292Support for device listing and matching was re-implemented by 293Kenneth Merry, and first appeared in 294.Fx 3.0 . 295.Sh AUTHORS 296.An Kenneth Merry Aq ken@FreeBSD.org 297.Sh BUGS 298It isn't possible for users to specify an accurate offset into the device 299list without calling the 300.Dv PCIOCGETCONF 301at least once, since they have no way of knowing the current generation 302number otherwise. This probably isn't a serious problem, though, since 303users can easily narrow their search by specifying a pattern or patterns 304for the kernel to match against. 305