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