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_ECAM
125	bool
126
127config PCI_LOCKLESS_CONFIG
128	bool
129
130config PCI_BRIDGE_EMUL
131	bool
132
133config PCI_IOV
134	bool "PCI IOV support"
135	select PCI_ATS
136	help
137	  I/O Virtualization is a PCI feature supported by some devices
138	  which allows them to create virtual devices which share their
139	  physical resources.
140
141	  If unsure, say N.
142
143config PCI_PRI
144	bool "PCI PRI support"
145	select PCI_ATS
146	help
147	  PRI is the PCI Page Request Interface. It allows PCI devices that are
148	  behind an IOMMU to recover from page faults.
149
150	  If unsure, say N.
151
152config PCI_PASID
153	bool "PCI PASID support"
154	select PCI_ATS
155	help
156	  Process Address Space Identifiers (PASIDs) can be used by PCI devices
157	  to access more than one IO address space at the same time. To make
158	  use of this feature an IOMMU is required which also supports PASIDs.
159	  Select this option if you have such an IOMMU and want to compile the
160	  driver for it into your kernel.
161
162	  If unsure, say N.
163
164config PCI_P2PDMA
165	bool "PCI peer-to-peer transfer support"
166	depends on ZONE_DEVICE
167	select GENERIC_ALLOCATOR
168	help
169	  Enableѕ drivers to do PCI peer-to-peer transactions to and from
170	  BARs that are exposed in other devices that are the part of
171	  the hierarchy where peer-to-peer DMA is guaranteed by the PCI
172	  specification to work (ie. anything below a single PCI bridge).
173
174	  Many PCIe root complexes do not support P2P transactions and
175	  it's hard to tell which support it at all, so at this time,
176	  P2P DMA transactions must be between devices behind the same root
177	  port.
178
179	  If unsure, say N.
180
181config PCI_LABEL
182	def_bool y if (DMI || ACPI)
183	select NLS
184
185config PCI_HYPERV
186	tristate "Hyper-V PCI Frontend"
187	depends on ((X86 && X86_64) || ARM64) && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && SYSFS
188	select PCI_HYPERV_INTERFACE
189	help
190	  The PCI device frontend driver allows the kernel to import arbitrary
191	  PCI devices from a PCI backend to support PCI driver domains.
192
193choice
194	prompt "PCI Express hierarchy optimization setting"
195	default PCIE_BUS_DEFAULT
196	depends on PCI && EXPERT
197	help
198	  MPS (Max Payload Size) and MRRS (Max Read Request Size) are PCIe
199	  device parameters that affect performance and the ability to
200	  support hotplug and peer-to-peer DMA.
201
202	  The following choices set the MPS and MRRS optimization strategy
203	  at compile-time.  The choices are the same as those offered for
204	  the kernel command-line parameter 'pci', i.e.,
205	  'pci=pcie_bus_tune_off', 'pci=pcie_bus_safe',
206	  'pci=pcie_bus_perf', and 'pci=pcie_bus_peer2peer'.
207
208	  This is a compile-time setting and can be overridden by the above
209	  command-line parameters.  If unsure, choose PCIE_BUS_DEFAULT.
210
211config PCIE_BUS_TUNE_OFF
212	bool "Tune Off"
213	depends on PCI
214	help
215	  Use the BIOS defaults; don't touch MPS at all.  This is the same
216	  as booting with 'pci=pcie_bus_tune_off'.
217
218config PCIE_BUS_DEFAULT
219	bool "Default"
220	depends on PCI
221	help
222	  Default choice; ensure that the MPS matches upstream bridge.
223
224config PCIE_BUS_SAFE
225	bool "Safe"
226	depends on PCI
227	help
228	  Use largest MPS that boot-time devices support.  If you have a
229	  closed system with no possibility of adding new devices, this
230	  will use the largest MPS that's supported by all devices.  This
231	  is the same as booting with 'pci=pcie_bus_safe'.
232
233config PCIE_BUS_PERFORMANCE
234	bool "Performance"
235	depends on PCI
236	help
237	  Use MPS and MRRS for best performance.  Ensure that a given
238	  device's MPS is no larger than its parent MPS, which allows us to
239	  keep all switches/bridges to the max MPS supported by their
240	  parent.  This is the same as booting with 'pci=pcie_bus_perf'.
241
242config PCIE_BUS_PEER2PEER
243	bool "Peer2peer"
244	depends on PCI
245	help
246	  Set MPS = 128 for all devices.  MPS configuration effected by the
247	  other options could cause the MPS on one root port to be
248	  different than that of the MPS on another, which may cause
249	  hot-added devices or peer-to-peer DMA to fail.  Set MPS to the
250	  smallest possible value (128B) system-wide to avoid these issues.
251	  This is the same as booting with 'pci=pcie_bus_peer2peer'.
252
253endchoice
254
255config VGA_ARB
256	bool "VGA Arbitration" if EXPERT
257	default y
258	depends on (PCI && !S390)
259	help
260	  Some "legacy" VGA devices implemented on PCI typically have the same
261	  hard-decoded addresses as they did on ISA. When multiple PCI devices
262	  are accessed at same time they need some kind of coordination. Please
263	  see Documentation/gpu/vgaarbiter.rst for more details. Select this to
264	  enable VGA arbiter.
265
266config VGA_ARB_MAX_GPUS
267	int "Maximum number of GPUs"
268	default 16
269	depends on VGA_ARB
270	help
271	  Reserves space in the kernel to maintain resource locking for
272	  multiple GPUS.  The overhead for each GPU is very small.
273
274source "drivers/pci/hotplug/Kconfig"
275source "drivers/pci/controller/Kconfig"
276source "drivers/pci/endpoint/Kconfig"
277source "drivers/pci/switch/Kconfig"
278
279endif
280