1 # SPDX-License-Identifier: GPL-2.0 2 # 3 # PCI configuration 4 # 5 6 # select this to offer the PCI prompt 7 config HAVE_PCI 8 bool 9 10 # select this to unconditionally force on PCI support 11 config 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 18 config GENERIC_PCI_IOMAP 19 bool 20 21 menuconfig PCI 22 bool "PCI support" 23 depends on HAVE_PCI 24 help 25 This option enables support for the PCI local bus, including 26 support for PCI-X and the foundations for PCI Express support. 27 Say 'Y' here unless you know what you are doing. 28 29 if PCI 30 31 config PCI_DOMAINS 32 bool 33 depends on PCI 34 35 config PCI_DOMAINS_GENERIC 36 bool 37 select PCI_DOMAINS 38 39 config PCI_SYSCALL 40 bool 41 42 source "drivers/pci/pcie/Kconfig" 43 44 config PCI_MSI 45 bool "Message Signaled Interrupts (MSI and MSI-X)" 46 select GENERIC_MSI_IRQ 47 help 48 This allows device drivers to enable MSI (Message Signaled 49 Interrupts). Message Signaled Interrupts enable a device to 50 generate an interrupt using an inbound Memory Write on its 51 PCI bus instead of asserting a device IRQ pin. 52 53 Use of PCI MSI interrupts can be disabled at kernel boot time 54 by using the 'pci=nomsi' option. This disables MSI for the 55 entire system. 56 57 If you don't know what to do here, say Y. 58 59 config PCI_MSI_ARCH_FALLBACKS 60 bool 61 62 config 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 70 config 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 80 config 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 92 config 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. 99 100 config 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. 110 111 config 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. 120 121 config PCI_ATS 122 bool 123 124 config PCI_DOE 125 bool 126 127 config PCI_ECAM 128 bool 129 130 config PCI_LOCKLESS_CONFIG 131 bool 132 133 config PCI_BRIDGE_EMUL 134 bool 135 136 config 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. 145 146 config PCI_NPEM 147 bool "Native PCIe Enclosure Management" 148 depends on LEDS_CLASS=y 149 help 150 Support for Native PCIe Enclosure Management. It allows managing LED 151 indications in storage enclosures. Enclosure must support following 152 indications: OK, Locate, Fail, Rebuild, other indications are 153 optional. 154 155 config PCI_PRI 156 bool "PCI PRI support" 157 select PCI_ATS 158 help 159 PRI is the PCI Page Request Interface. It allows PCI devices that are 160 behind an IOMMU to recover from page faults. 161 162 If unsure, say N. 163 164 config PCI_PASID 165 bool "PCI PASID support" 166 select PCI_ATS 167 help 168 Process Address Space Identifiers (PASIDs) can be used by PCI devices 169 to access more than one IO address space at the same time. To make 170 use of this feature an IOMMU is required which also supports PASIDs. 171 Select this option if you have such an IOMMU and want to compile the 172 driver for it into your kernel. 173 174 If unsure, say N. 175 176 config PCI_P2PDMA 177 bool "PCI peer-to-peer transfer support" 178 depends on ZONE_DEVICE 179 # 180 # The need for the scatterlist DMA bus address flag means PCI P2PDMA 181 # requires 64bit 182 # 183 depends on 64BIT 184 select GENERIC_ALLOCATOR 185 select NEED_SG_DMA_FLAGS 186 help 187 Enables drivers to do PCI peer-to-peer transactions to and from 188 BARs that are exposed in other devices that are the part of 189 the hierarchy where peer-to-peer DMA is guaranteed by the PCI 190 specification to work (ie. anything below a single PCI bridge). 191 192 Many PCIe root complexes do not support P2P transactions and 193 it's hard to tell which support it at all, so at this time, 194 P2P DMA transactions must be between devices behind the same root 195 port. 196 197 If unsure, say N. 198 199 config PCI_LABEL 200 def_bool y if (DMI || ACPI) 201 select NLS 202 203 config PCI_HYPERV 204 tristate "Hyper-V PCI Frontend" 205 depends on ((X86 && X86_64) || ARM64) && HYPERV && PCI_MSI && SYSFS 206 select PCI_HYPERV_INTERFACE 207 help 208 The PCI device frontend driver allows the kernel to import arbitrary 209 PCI devices from a PCI backend to support PCI driver domains. 210 211 config PCI_DYNAMIC_OF_NODES 212 bool "Create Device tree nodes for PCI devices" 213 depends on OF_IRQ 214 select OF_DYNAMIC 215 help 216 This option enables support for generating device tree nodes for some 217 PCI devices. Thus, the driver of this kind can load and overlay 218 flattened device tree for its downstream devices. 219 220 Once this option is selected, the device tree nodes will be generated 221 for all PCI bridges. 222 223 choice 224 prompt "PCI Express hierarchy optimization setting" 225 default PCIE_BUS_DEFAULT 226 depends on PCI && EXPERT 227 help 228 MPS (Max Payload Size) and MRRS (Max Read Request Size) are PCIe 229 device parameters that affect performance and the ability to 230 support hotplug and peer-to-peer DMA. 231 232 The following choices set the MPS and MRRS optimization strategy 233 at compile-time. The choices are the same as those offered for 234 the kernel command-line parameter 'pci', i.e., 235 'pci=pcie_bus_tune_off', 'pci=pcie_bus_safe', 236 'pci=pcie_bus_perf', and 'pci=pcie_bus_peer2peer'. 237 238 This is a compile-time setting and can be overridden by the above 239 command-line parameters. If unsure, choose PCIE_BUS_DEFAULT. 240 241 config PCIE_BUS_TUNE_OFF 242 bool "Tune Off" 243 depends on PCI 244 help 245 Use the BIOS defaults; don't touch MPS at all. This is the same 246 as booting with 'pci=pcie_bus_tune_off'. 247 248 config PCIE_BUS_DEFAULT 249 bool "Default" 250 depends on PCI 251 help 252 Default choice; ensure that the MPS matches upstream bridge. 253 254 config PCIE_BUS_SAFE 255 bool "Safe" 256 depends on PCI 257 help 258 Use largest MPS that boot-time devices support. If you have a 259 closed system with no possibility of adding new devices, this 260 will use the largest MPS that's supported by all devices. This 261 is the same as booting with 'pci=pcie_bus_safe'. 262 263 config PCIE_BUS_PERFORMANCE 264 bool "Performance" 265 depends on PCI 266 help 267 Use MPS and MRRS for best performance. Ensure that a given 268 device's MPS is no larger than its parent MPS, which allows us to 269 keep all switches/bridges to the max MPS supported by their 270 parent. This is the same as booting with 'pci=pcie_bus_perf'. 271 272 config PCIE_BUS_PEER2PEER 273 bool "Peer2peer" 274 depends on PCI 275 help 276 Set MPS = 128 for all devices. MPS configuration effected by the 277 other options could cause the MPS on one root port to be 278 different than that of the MPS on another, which may cause 279 hot-added devices or peer-to-peer DMA to fail. Set MPS to the 280 smallest possible value (128B) system-wide to avoid these issues. 281 This is the same as booting with 'pci=pcie_bus_peer2peer'. 282 283 endchoice 284 285 config VGA_ARB 286 bool "VGA Arbitration" if EXPERT 287 default y 288 depends on (PCI && !S390) 289 help 290 Some "legacy" VGA devices implemented on PCI typically have the same 291 hard-decoded addresses as they did on ISA. When multiple PCI devices 292 are accessed at same time they need some kind of coordination. Please 293 see Documentation/gpu/vgaarbiter.rst for more details. Select this to 294 enable VGA arbiter. 295 296 config VGA_ARB_MAX_GPUS 297 int "Maximum number of GPUs" 298 default 16 299 depends on VGA_ARB 300 help 301 Reserves space in the kernel to maintain resource locking for 302 multiple GPUS. The overhead for each GPU is very small. 303 304 source "drivers/pci/hotplug/Kconfig" 305 source "drivers/pci/controller/Kconfig" 306 source "drivers/pci/endpoint/Kconfig" 307 source "drivers/pci/switch/Kconfig" 308 source "drivers/pci/pwrctl/Kconfig" 309 310 endif 311