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