tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1# SPDX-License-Identifier: GPL-2.0
2#
3# PCI configuration
4#
5
6# select this to offer the PCI prompt
7config HAVE_PCI
8 bool
9
10# select this to unconditionally force on PCI support
11config FORCE_PCI
12 bool
13 select HAVE_PCI
14 select PCI
15
16# select this to provide a generic PCI iomap,
17# without PCI itself having to be defined
18config GENERIC_PCI_IOMAP
19 bool
20
21menuconfig PCI
22 bool "PCI support"
23 depends on HAVE_PCI
24 depends on MMU
25 help
26 This option enables support for the PCI local bus, including
27 support for PCI-X and the foundations for PCI Express support.
28 Say 'Y' here unless you know what you are doing.
29
30if PCI
31
32config PCI_DOMAINS
33 bool
34 depends on PCI
35
36config PCI_DOMAINS_GENERIC
37 bool
38 select PCI_DOMAINS
39
40config PCI_SYSCALL
41 bool
42
43source "drivers/pci/pcie/Kconfig"
44
45config PCI_MSI
46 bool "Message Signaled Interrupts (MSI and MSI-X)"
47 select GENERIC_MSI_IRQ
48 help
49 This allows device drivers to enable MSI (Message Signaled
50 Interrupts). Message Signaled Interrupts enable a device to
51 generate an interrupt using an inbound Memory Write on its
52 PCI bus instead of asserting a device IRQ pin.
53
54 Use of PCI MSI interrupts can be disabled at kernel boot time
55 by using the 'pci=nomsi' option. This disables MSI for the
56 entire system.
57
58 If you don't know what to do here, say Y.
59
60config PCI_MSI_ARCH_FALLBACKS
61 bool
62
63config PCI_QUIRKS
64 default y
65 bool "Enable PCI quirk workarounds" if EXPERT
66 help
67 This enables workarounds for various PCI chipset bugs/quirks.
68 Disable this only if your target machine is unaffected by PCI
69 quirks.
70
71config PCI_DEBUG
72 bool "PCI Debugging"
73 depends on DEBUG_KERNEL
74 help
75 Say Y here if you want the PCI core to produce a bunch of debug
76 messages to the system log. Select this if you are having a
77 problem with PCI support and want to see more of what is going on.
78
79 When in doubt, say N.
80
81config PCI_REALLOC_ENABLE_AUTO
82 bool "Enable PCI resource re-allocation detection"
83 depends on PCI_IOV
84 help
85 Say Y here if you want the PCI core to detect if PCI resource
86 re-allocation needs to be enabled. You can always use pci=realloc=on
87 or pci=realloc=off to override it. It will automatically
88 re-allocate PCI resources if SR-IOV BARs have not been allocated by
89 the BIOS.
90
91 When in doubt, say N.
92
93config PCI_STUB
94 tristate "PCI Stub driver"
95 help
96 Say Y or M here if you want be able to reserve a PCI device
97 when it is going to be assigned to a guest operating system.
98
99 When in doubt, say N.
100
101config PCI_PF_STUB
102 tristate "PCI PF Stub driver"
103 depends on PCI_IOV
104 help
105 Say Y or M here if you want to enable support for devices that
106 require SR-IOV support, while at the same time the PF (Physical
107 Function) itself is not providing any actual services on the
108 host itself such as storage or networking.
109
110 When in doubt, say N.
111
112config XEN_PCIDEV_FRONTEND
113 tristate "Xen PCI Frontend"
114 depends on XEN_PV
115 select PCI_XEN
116 select XEN_XENBUS_FRONTEND
117 default y
118 help
119 The PCI device frontend driver allows the kernel to import arbitrary
120 PCI devices from a PCI backend to support PCI driver domains.
121
122config PCI_ATS
123 bool
124
125config PCI_DOE
126 bool "Enable PCI Data Object Exchange (DOE) support"
127 help
128 Say Y here if you want be able to communicate with PCIe DOE
129 mailboxes.
130
131config PCI_ECAM
132 bool
133
134config PCI_LOCKLESS_CONFIG
135 bool
136
137config PCI_BRIDGE_EMUL
138 bool
139
140config PCI_IOV
141 bool "PCI IOV support"
142 select PCI_ATS
143 help
144 I/O Virtualization is a PCI feature supported by some devices
145 which allows them to create virtual devices which share their
146 physical resources.
147
148 If unsure, say N.
149
150config PCI_NPEM
151 bool "Native PCIe Enclosure Management"
152 depends on LEDS_CLASS=y
153 help
154 Support for Native PCIe Enclosure Management. It allows managing LED
155 indications in storage enclosures. Enclosure must support following
156 indications: OK, Locate, Fail, Rebuild, other indications are
157 optional.
158
159config PCI_PRI
160 bool "PCI PRI support"
161 select PCI_ATS
162 help
163 PRI is the PCI Page Request Interface. It allows PCI devices that are
164 behind an IOMMU to recover from page faults.
165
166 If unsure, say N.
167
168config PCI_PASID
169 bool "PCI PASID support"
170 select PCI_ATS
171 help
172 Process Address Space Identifiers (PASIDs) can be used by PCI devices
173 to access more than one IO address space at the same time. To make
174 use of this feature an IOMMU is required which also supports PASIDs.
175 Select this option if you have such an IOMMU and want to compile the
176 driver for it into your kernel.
177
178 If unsure, say N.
179
180config PCIE_TPH
181 bool "TLP Processing Hints"
182 help
183 This option adds support for PCIe TLP Processing Hints (TPH).
184 TPH allows endpoint devices to provide optimization hints, such as
185 desired caching behavior, for requests that target memory space.
186 These hints, called Steering Tags, can empower the system hardware
187 to optimize the utilization of platform resources.
188
189config PCI_P2PDMA
190 bool "PCI peer-to-peer transfer support"
191 depends on ZONE_DEVICE
192 #
193 # The need for the scatterlist DMA bus address flag means PCI P2PDMA
194 # requires 64bit
195 #
196 depends on 64BIT
197 select GENERIC_ALLOCATOR
198 select NEED_SG_DMA_FLAGS
199 help
200 Enables drivers to do PCI peer-to-peer transactions to and from
201 BARs that are exposed in other devices that are the part of
202 the hierarchy where peer-to-peer DMA is guaranteed by the PCI
203 specification to work (ie. anything below a single PCI bridge).
204
205 Many PCIe root complexes do not support P2P transactions and
206 it's hard to tell which support it at all, so at this time,
207 P2P DMA transactions must be between devices behind the same root
208 port.
209
210 Enabling this option will reduce the entropy of x86 KASLR memory
211 regions. For example - on a 46 bit system, the entropy goes down
212 from 16 bits to 15 bits. The actual reduction in entropy depends
213 on the physical address bits, on processor features, kernel config
214 (5 level page table) and physical memory present on the system.
215
216 If unsure, say N.
217
218config PCI_LABEL
219 def_bool y if (DMI || ACPI)
220 select NLS
221
222config PCI_HYPERV
223 tristate "Hyper-V PCI Frontend"
224 depends on ((X86 && X86_64) || ARM64) && HYPERV && PCI_MSI && SYSFS
225 select PCI_HYPERV_INTERFACE
226 select IRQ_MSI_LIB
227 help
228 The PCI device frontend driver allows the kernel to import arbitrary
229 PCI devices from a PCI backend to support PCI driver domains.
230
231config PCI_DYNAMIC_OF_NODES
232 bool "Create Device tree nodes for PCI devices"
233 depends on OF_IRQ
234 select OF_DYNAMIC
235 help
236 This option enables support for generating device tree nodes for some
237 PCI devices. Thus, the driver of this kind can load and overlay
238 flattened device tree for its downstream devices.
239
240 Once this option is selected, the device tree nodes will be generated
241 for all PCI bridges.
242
243choice
244 prompt "PCI Express hierarchy optimization setting"
245 default PCIE_BUS_DEFAULT
246 depends on PCI && EXPERT
247 help
248 MPS (Max Payload Size) and MRRS (Max Read Request Size) are PCIe
249 device parameters that affect performance and the ability to
250 support hotplug and peer-to-peer DMA.
251
252 The following choices set the MPS and MRRS optimization strategy
253 at compile-time. The choices are the same as those offered for
254 the kernel command-line parameter 'pci', i.e.,
255 'pci=pcie_bus_tune_off', 'pci=pcie_bus_safe',
256 'pci=pcie_bus_perf', and 'pci=pcie_bus_peer2peer'.
257
258 This is a compile-time setting and can be overridden by the above
259 command-line parameters. If unsure, choose PCIE_BUS_DEFAULT.
260
261config PCIE_BUS_TUNE_OFF
262 bool "Tune Off"
263 depends on PCI
264 help
265 Use the BIOS defaults; don't touch MPS at all. This is the same
266 as booting with 'pci=pcie_bus_tune_off'.
267
268config PCIE_BUS_DEFAULT
269 bool "Default"
270 depends on PCI
271 help
272 Default choice; ensure that the MPS matches upstream bridge.
273
274config PCIE_BUS_SAFE
275 bool "Safe"
276 depends on PCI
277 help
278 Use largest MPS that boot-time devices support. If you have a
279 closed system with no possibility of adding new devices, this
280 will use the largest MPS that's supported by all devices. This
281 is the same as booting with 'pci=pcie_bus_safe'.
282
283config PCIE_BUS_PERFORMANCE
284 bool "Performance"
285 depends on PCI
286 help
287 Use MPS and MRRS for best performance. Ensure that a given
288 device's MPS is no larger than its parent MPS, which allows us to
289 keep all switches/bridges to the max MPS supported by their
290 parent. This is the same as booting with 'pci=pcie_bus_perf'.
291
292config PCIE_BUS_PEER2PEER
293 bool "Peer2peer"
294 depends on PCI
295 help
296 Set MPS = 128 for all devices. MPS configuration effected by the
297 other options could cause the MPS on one root port to be
298 different than that of the MPS on another, which may cause
299 hot-added devices or peer-to-peer DMA to fail. Set MPS to the
300 smallest possible value (128B) system-wide to avoid these issues.
301 This is the same as booting with 'pci=pcie_bus_peer2peer'.
302
303endchoice
304
305config VGA_ARB
306 bool "VGA Arbitration" if EXPERT
307 default y
308 depends on (PCI && !S390)
309 help
310 Some "legacy" VGA devices implemented on PCI typically have the same
311 hard-decoded addresses as they did on ISA. When multiple PCI devices
312 are accessed at same time they need some kind of coordination. Please
313 see Documentation/gpu/vgaarbiter.rst for more details. Select this to
314 enable VGA arbiter.
315
316config VGA_ARB_MAX_GPUS
317 int "Maximum number of GPUs"
318 default 16
319 depends on VGA_ARB
320 help
321 Reserves space in the kernel to maintain resource locking for
322 multiple GPUS. The overhead for each GPU is very small.
323
324source "drivers/pci/hotplug/Kconfig"
325source "drivers/pci/controller/Kconfig"
326source "drivers/pci/endpoint/Kconfig"
327source "drivers/pci/switch/Kconfig"
328source "drivers/pci/pwrctrl/Kconfig"
329
330endif