File Formats pci(4)
NAME
pci, pcie - configuration files for PCI and PCI Express dev-
ice drivers
DESCRIPTION
The Peripheral Component Interconnect (PCI) bus is a little
endian bus. PCI Express (PCIe) and PCI-X are successors to
PCI. All three types of devices share the same configuration
parameters. What is specified here for PCI devices applies
to PCI-X 1.0 devices as well. All three types of devices are
self-identifying, which means that these devices provide
configuration parameters to the system that allow the system
to identify the device and its driver. The configuration
parameters are represented in the form of name-value pairs
that can be retrieved using the DI property interfaces. See
ddiproplookup(9F) for details.
The bus properties of PCI devices or logical bus properties
of PCIe devices are derived from PCI configuration space, or
supplied by the Fcode PROM, if it exists. Therefore, driver
configuration files are not necessary for these devices.
On some occasions, drivers for PCI and PCIe devices can use
driver configuration files to provide driver private proper-
ties through the global property mechanism. See
driver.conf(4) for further details. Driver configuration
files can also be used to augment or override properties for
a specific instance of a driver.
All bus drivers of PCI and PCIe devices recognize the fol-
lowing properties:
reg An arbitrary length array where each element
of the array consists of a 5-tuple of 32-bit
values. Each array element describes a logi-
cally contiguous mappable resource on the PCI
bus or PCIe device tree.
The first three values in the 5-tuple describe
the PCI address of the mappable resource. The
first tuple contains the following informa-
tion:
Bits 0 - 7 8-bit register number
Bits 8 - 10 3-bit function number
Bits 11 - 15 5-bit device number
Bits 16 - 23 8-bit bus number
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Bits 24 - 25 2-bit address space type identifier
Bits 31 - 28 Register number extended bits 8:11
for extended config space. Zero for
conventional configuration space.
The address space type identifier can be
interpreted as follows:
0x0 configuration space
0x1 I/O space
0x2 32-bit memory space address
0x3 64-bit memory space address
The bus number is a unique identifying number
assigned to each PCI bus or PCIe logical bus
within its domain.
The device number is a unique identifying
number assigned to each device on a PCI bus or
PCIe logical bus. Note that a device number is
unique only within the set of device numbers
for a particular bus or logical bus.
Each PCI or PCIe device can have one to eight
logically independent functions, each with its
own independent set of configuration regis-
ters. Each function on a device is assigned a
function number. For a device with only one
function, the function number must be 0.
The register number fields select a particular
register within the set of configuration
registers corresponding to the selected func-
tion. When the address space type identifier
indicates configuration space, non-zero regis-
ter number extended bits select registers in
extended configuration space.
The second and third values in the reg pro-
perty 5-tuple specify the 64-bit address of
the mappable resource within the PCI or PCIe
address domain. The second 32-bit tuple
corresponds to the high order four bytes of
the 64-bit address. The third 32-bit tuple
corresponds to the low order bytes.
The fourth and fifth 32-bit values in the 5-
tuple reg property specify the size of the
mappable resource. The size is a 64-bit value,
where the fourth tuple corresponds to the high
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order bytes of the 64-bit size and the fifth
corresponds to the low order.
The driver can refer to the elements of this
array by index, and construct kernel mappings
to these addresses using
ddiregsmapsetup(9F). The index into the
array is passed as the rnumber argument of
ddiregsmapsetup(9F).
At a high-level interrupt context, you can use
the ddiget* and ddiput* family of functions
to access I/O and memory space. However,
access to configuration space is not allowed
when running at a high-interrupt level.
interrupts This property consists of a single-integer
element array. Valid interrupt property values
are 1, 2, 3, and 4. This value is derived
directly from the contents of the device's
configuration-interrupt-pin register.
A driver should use an index value of 0 when
registering its interrupt handler with the DI
interrupt interfaces.
All PCI and PCIe devices support the reg property. The dev-
ice number and function number as derived from the reg pro-
perty are used to construct the address part of the device
name under /devices.
Only devices that generate interrupts support an interrupts
property.
Occasionally it might be necessary to override or augment
the configuration information supplied by a PCI or PCIe dev-
ice. This change can be achieved by writing a driver confi-
guration file that describes a prototype device node specif-
ication containing the additional properties required.
For the system to merge the prototype node specification
into an actual device node, certain conditions must be met.
o First, the name property must be identical. The
value of the name property needs to match the bind-
ing name of the device. The binding name is the
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name chosen by the system to bind a driver to a
device and is either an alias associated with the
driver or the hardware node name of the device.
o Second, the parent property must identify the PCI
bus or PCIe logical bus.
o Third, the unit-address property must identify the
card. The format of the unit-address property is:
D[,F]
where D is the device number and F is the function number.
If the function number is 0, only D is specified.
EXAMPLES
Example 1 Sample Configuration File
An example configuration file called ACME,scsi-hba.conf for
a PCI driver called ACME,scsi-hba follows:
#
# Copyright (c) 1995, ACME SCSI Host Bus Adaptor
# ident "@(#)ACME,scsi-hba.conf 1.1 96/02/04"
name="ACME,scsi-hba" parent="/pci@1,0/pci@1f,4000"
unit-address="3" scsi-initiator-id=6;
hba-advanced-mode="on";
hba-dma-speed=10;
In this example, a property scsi-initiator-id specifies the
SCSI bus initiator id that the adapter should use, for just
one particular instance of adapter installed in the machine.
The name property identifies the driver and the parent pro-
perty to identify the particular bus the card is plugged
into. This example uses the parent's full path name to iden-
tify the bus. The unit-address property identifies the card
itself, with device number of 3 and function number of 0.
Two global driver properties are also created: hba-
advanced-mode (which has the string value on) and hba-dma-
speed (which has the value 10 M bit/s). These properties
apply to all device nodes of the ACME,scsi-hba.
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Configuration files for PCIe devices are similar. Shown
below is an example configuration file called ACME,pcie-
widget.conf for a PCIe driver called ACME,pcie-widget.
#
# Copyright (c) 2005, ACME PCIe Widget Adapter
# ident "@(#)ACME,pcie-widget.conf 1.1 05/11/14"
name="ACME,pcie-widget" parent="/pci@780" unit-address="2,1"
debug-mode=12;
In this example, we provide a property debug-mode for a par-
ticular PCIe device. As before, the logical bus is identi-
fied by the pathname of the parent of the device. The device
has a device number of 2, and a function number of 1.
ATRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
ATRIBUTE TYPE ATRIBUTE VALUE
Architecture SPARC, x86
SEE ALSO
driver.conf(4), attributes(5), ddiintraddhandler(9F),
ddiproplookup(9F), ddiregsmapsetup(9F)
Writing Device Drivers
IE 1275 PCI Bus Binding
http:/playground.sun.com/1275/bindings/pci/pci-express.txt
NOTES
PCIe devices support an extended configuration space una-
vailable to PCI devices. While PCIe devices can be operated
using a PCI device driver, operating them using a PCIe dev-
ice driver can make use of the extended properties and
features made available only in the extended configuration
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space.
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