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
16menuconfig PCI
17	bool "PCI support"
18	depends on HAVE_PCI
19	help
20	  This option enables support for the PCI local bus, including
21	  support for PCI-X and the foundations for PCI Express support.
22	  Say 'Y' here unless you know what you are doing.
23
24if PCI
25
26config PCI_DOMAINS
27	bool
28	depends on PCI
29
30config PCI_DOMAINS_GENERIC
31	bool
32	select PCI_DOMAINS
33
34config PCI_SYSCALL
35	bool
36
37source "drivers/pci/pcie/Kconfig"
38
39config PCI_MSI
40	bool "Message Signaled Interrupts (MSI and MSI-X)"
41	select GENERIC_MSI_IRQ
42	help
43	   This allows device drivers to enable MSI (Message Signaled
44	   Interrupts).  Message Signaled Interrupts enable a device to
45	   generate an interrupt using an inbound Memory Write on its
46	   PCI bus instead of asserting a device IRQ pin.
47
48	   Use of PCI MSI interrupts can be disabled at kernel boot time
49	   by using the 'pci=nomsi' option.  This disables MSI for the
50	   entire system.
51
52	   If you don't know what to do here, say Y.
53
54config PCI_MSI_IRQ_DOMAIN
55	def_bool y
56	depends on PCI_MSI
57	select GENERIC_MSI_IRQ_DOMAIN
58
59config PCI_MSI_ARCH_FALLBACKS
60	bool
61
62config PCI_QUIRKS
63	default y
64	bool "Enable PCI quirk workarounds" if EXPERT
65	help
66	  This enables workarounds for various PCI chipset bugs/quirks.
67	  Disable this only if your target machine is unaffected by PCI
68	  quirks.
69
70config PCI_DEBUG
71	bool "PCI Debugging"
72	depends on DEBUG_KERNEL
73	help
74	  Say Y here if you want the PCI core to produce a bunch of debug
75	  messages to the system log.  Select this if you are having a
76	  problem with PCI support and want to see more of what is going on.
77
78	  When in doubt, say N.
79
80config PCI_REALLOC_ENABLE_AUTO
81	bool "Enable PCI resource re-allocation detection"
82	depends on PCI_IOV
83	help
84	  Say Y here if you want the PCI core to detect if PCI resource
85	  re-allocation needs to be enabled. You can always use pci=realloc=on
86	  or pci=realloc=off to override it.  It will automatically
87	  re-allocate PCI resources if SR-IOV BARs have not been allocated by
88	  the BIOS.
89
90	  When in doubt, say N.
91
92config PCI_STUB
93	tristate "PCI Stub driver"
94	help
95	  Say Y or M here if you want be able to reserve a PCI device
96	  when it is going to be assigned to a guest operating system.
97
98	  When in doubt, say N.
99
100config PCI_PF_STUB
101	tristate "PCI PF Stub driver"
102	depends on PCI_IOV
103	help
104	  Say Y or M here if you want to enable support for devices that
105	  require SR-IOV support, while at the same time the PF (Physical
106	  Function) itself is not providing any actual services on the
107	  host itself such as storage or networking.
108
109	  When in doubt, say N.
110
111config XEN_PCIDEV_FRONTEND
112	tristate "Xen PCI Frontend"
113	depends on XEN_PV
114	select PCI_XEN
115	select XEN_XENBUS_FRONTEND
116	default y
117	help
118	  The PCI device frontend driver allows the kernel to import arbitrary
119	  PCI devices from a PCI backend to support PCI driver domains.
120
121config PCI_ATS
122	bool
123
124config PCI_DOE
125	bool
126
127config PCI_ECAM
128	bool
129
130config PCI_LOCKLESS_CONFIG
131	bool
132
133config PCI_BRIDGE_EMUL
134	bool
135
136config PCI_IOV
137	bool "PCI IOV support"
138	select PCI_ATS
139	help
140	  I/O Virtualization is a PCI feature supported by some devices
141	  which allows them to create virtual devices which share their
142	  physical resources.
143
144	  If unsure, say N.
145
146config PCI_PRI
147	bool "PCI PRI support"
148	select PCI_ATS
149	help
150	  PRI is the PCI Page Request Interface. It allows PCI devices that are
151	  behind an IOMMU to recover from page faults.
152
153	  If unsure, say N.
154
155config PCI_PASID
156	bool "PCI PASID support"
157	select PCI_ATS
158	help
159	  Process Address Space Identifiers (PASIDs) can be used by PCI devices
160	  to access more than one IO address space at the same time. To make
161	  use of this feature an IOMMU is required which also supports PASIDs.
162	  Select this option if you have such an IOMMU and want to compile the
163	  driver for it into your kernel.
164
165	  If unsure, say N.
166
167config PCI_P2PDMA
168	bool "PCI peer-to-peer transfer support"
169	depends on ZONE_DEVICE
170	#
171	# The need for the scatterlist DMA bus address flag means PCI P2PDMA
172	# requires 64bit
173	#
174	depends on 64BIT
175	select GENERIC_ALLOCATOR
176	help
177	  Enableѕ drivers to do PCI peer-to-peer transactions to and from
178	  BARs that are exposed in other devices that are the part of
179	  the hierarchy where peer-to-peer DMA is guaranteed by the PCI
180	  specification to work (ie. anything below a single PCI bridge).
181
182	  Many PCIe root complexes do not support P2P transactions and
183	  it's hard to tell which support it at all, so at this time,
184	  P2P DMA transactions must be between devices behind the same root
185	  port.
186
187	  If unsure, say N.
188
189config PCI_LABEL
190	def_bool y if (DMI || ACPI)
191	select NLS
192
193config PCI_HYPERV
194	tristate "Hyper-V PCI Frontend"
195	depends on ((X86 && X86_64) || ARM64) && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && SYSFS
196	select PCI_HYPERV_INTERFACE
197	help
198	  The PCI device frontend driver allows the kernel to import arbitrary
199	  PCI devices from a PCI backend to support PCI driver domains.
200
201choice
202	prompt "PCI Express hierarchy optimization setting"
203	default PCIE_BUS_DEFAULT
204	depends on PCI && EXPERT
205	help
206	  MPS (Max Payload Size) and MRRS (Max Read Request Size) are PCIe
207	  device parameters that affect performance and the ability to
208	  support hotplug and peer-to-peer DMA.
209
210	  The following choices set the MPS and MRRS optimization strategy
211	  at compile-time.  The choices are the same as those offered for
212	  the kernel command-line parameter 'pci', i.e.,
213	  'pci=pcie_bus_tune_off', 'pci=pcie_bus_safe',
214	  'pci=pcie_bus_perf', and 'pci=pcie_bus_peer2peer'.
215
216	  This is a compile-time setting and can be overridden by the above
217	  command-line parameters.  If unsure, choose PCIE_BUS_DEFAULT.
218
219config PCIE_BUS_TUNE_OFF
220	bool "Tune Off"
221	depends on PCI
222	help
223	  Use the BIOS defaults; don't touch MPS at all.  This is the same
224	  as booting with 'pci=pcie_bus_tune_off'.
225
226config PCIE_BUS_DEFAULT
227	bool "Default"
228	depends on PCI
229	help
230	  Default choice; ensure that the MPS matches upstream bridge.
231
232config PCIE_BUS_SAFE
233	bool "Safe"
234	depends on PCI
235	help
236	  Use largest MPS that boot-time devices support.  If you have a
237	  closed system with no possibility of adding new devices, this
238	  will use the largest MPS that's supported by all devices.  This
239	  is the same as booting with 'pci=pcie_bus_safe'.
240
241config PCIE_BUS_PERFORMANCE
242	bool "Performance"
243	depends on PCI
244	help
245	  Use MPS and MRRS for best performance.  Ensure that a given
246	  device's MPS is no larger than its parent MPS, which allows us to
247	  keep all switches/bridges to the max MPS supported by their
248	  parent.  This is the same as booting with 'pci=pcie_bus_perf'.
249
250config PCIE_BUS_PEER2PEER
251	bool "Peer2peer"
252	depends on PCI
253	help
254	  Set MPS = 128 for all devices.  MPS configuration effected by the
255	  other options could cause the MPS on one root port to be
256	  different than that of the MPS on another, which may cause
257	  hot-added devices or peer-to-peer DMA to fail.  Set MPS to the
258	  smallest possible value (128B) system-wide to avoid these issues.
259	  This is the same as booting with 'pci=pcie_bus_peer2peer'.
260
261endchoice
262
263config VGA_ARB
264	bool "VGA Arbitration" if EXPERT
265	default y
266	depends on (PCI && !S390)
267	help
268	  Some "legacy" VGA devices implemented on PCI typically have the same
269	  hard-decoded addresses as they did on ISA. When multiple PCI devices
270	  are accessed at same time they need some kind of coordination. Please
271	  see Documentation/gpu/vgaarbiter.rst for more details. Select this to
272	  enable VGA arbiter.
273
274config VGA_ARB_MAX_GPUS
275	int "Maximum number of GPUs"
276	default 16
277	depends on VGA_ARB
278	help
279	  Reserves space in the kernel to maintain resource locking for
280	  multiple GPUS.  The overhead for each GPU is very small.
281
282source "drivers/pci/hotplug/Kconfig"
283source "drivers/pci/controller/Kconfig"
284source "drivers/pci/endpoint/Kconfig"
285source "drivers/pci/switch/Kconfig"
286
287endif
288