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