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