kernel/linux.git/drivers/pci/Makefile, branch linux-5.9.y

PCI: Allow building PCIe things without PCIEPORTBUS

2019-11-21T13:52:33+00:00

Some things in drivers/pci/pcie (aspm.c and ptm.c) do not depend on the PCIe portdrv, so we should be able to build them even if PCIEPORTBUS is not selected. Remove the PCIEPORTBUS guard from building pcie/. Link: https://lore.kernel.org/r/20191106222420.10216-6-helgaas@kernel.org Signed-off-by: Bjorn Helgaas Reviewed-by: Andrew Murray

PCI: OF: Allow of_pci_get_max_link_speed() to be used by PCI Endpoint drivers

2019-04-15T12:24:02+00:00

of_pci_get_max_link_speed() is built only if CONFIG_PCI is enabled. Make of_pci_get_max_link_speed() to be also used by PCI Endpoint controllers with just CONFIG_PCI_ENDPOINT enabled. Signed-off-by: Kishon Vijay Abraham I Signed-off-by: Sekhar Nori Signed-off-by: Lorenzo Pieralisi Acked-by: Bjorn Helgaas

PCI/ACPI: Allow ACPI to be built without CONFIG_PCI set

2018-12-20T09:19:49+00:00

We are compiling PCI code today for systems with ACPI and no PCI device present. Remove the useless code and reduce the tight dependency. Signed-off-by: Sinan Kaya Acked-by: Bjorn Helgaas # PCI parts Acked-by: Ingo Molnar Signed-off-by: Rafael J. Wysocki

Merge branch 'remotes/lorenzo/pci/controller-misc'

2018-10-20T16:45:47+00:00

- Remove redundant controller tests for "device_type == pci" (Rob Herring) - Document R-Car E3 (R8A77990) bindings (Tho Vu) - Add device tree support for R-Car r8a7744 (Biju Das) - Drop unused mvebu PCIe capability code (Thomas Petazzoni) - Add shared PCI bridge emulation code (Thomas Petazzoni) - Convert mvebu to use shared PCI bridge emulation (Thomas Petazzoni) - Add aardvark Root Port emulation (Thomas Petazzoni) * remotes/lorenzo/pci/controller-misc: PCI: aardvark: Implement emulated root PCI bridge config space PCI: mvebu: Convert to PCI emulated bridge config space PCI: mvebu: Drop unused PCI express capability code PCI: Introduce PCI bridge emulated config space common logic dt-bindings: PCI: rcar: Add device tree support for r8a7744 dt-bindings: PCI: rcar: Add device tree support for r8a7744 DT: pci: rcar-pci: document R8A77990 bindings PCI: Remove unnecessary check of device_type == pci

PCI: Introduce PCI bridge emulated config space common logic

2018-10-18T16:50:19+00:00

Some PCI host controllers do not expose a configuration space for the root port PCI bridge. Due to this, the Marvell Armada 370/38x/XP PCI controller driver (pci-mvebu) emulates a root port PCI bridge configuration space, and uses that to (among other things) dynamically create the memory windows that correspond to the PCI MEM and I/O regions. Since we now need to add a very similar logic for the Marvell Armada 37xx PCI controller driver (pci-aardvark), instead of duplicating the code, we create in this commit a common logic called pci-bridge-emul. The idea of this logic is to emulate a root port PCI bridge configuration space by providing configuration space read/write operations, and faking behind the scenes the configuration space of a PCI bridge. A PCI host controller driver simply has to call pci_bridge_emul_conf_read() and pci_bridge_emul_conf_write() to read/write the configuration space of the bridge. By default, the PCI bridge configuration space is simply emulated by a chunk of memory, but the PCI host controller can override the behavior of the read and write operations on a per-register basis to do additional actions if needed. We take care of complying with the behavior of the PCI configuration space registers in terms of bits that are read-write, read-only, reserved and write-1-to-clear. Signed-off-by: Thomas Petazzoni Signed-off-by: Lorenzo Pieralisi Acked-by: Bjorn Helgaas Reviewed-by: Russell King

PCI/P2PDMA: Support peer-to-peer memory

2018-10-10T19:00:54+00:00

Some PCI devices may have memory mapped in a BAR space that's intended for use in peer-to-peer transactions. To enable such transactions the memory must be registered with ZONE_DEVICE pages so it can be used by DMA interfaces in existing drivers. Add an interface for other subsystems to find and allocate chunks of P2P memory as necessary to facilitate transfers between two PCI peers: struct pci_dev *pci_p2pmem_find[_many](); int pci_p2pdma_distance[_many](); void *pci_alloc_p2pmem(); The new interface requires a driver to collect a list of client devices involved in the transaction then call pci_p2pmem_find() to obtain any suitable P2P memory. Alternatively, if the caller knows a device which provides P2P memory, they can use pci_p2pdma_distance() to determine if it is usable. With a suitable p2pmem device, memory can then be allocated with pci_alloc_p2pmem() for use in DMA transactions. Depending on hardware, using peer-to-peer memory may reduce the bandwidth of the transfer but can significantly reduce pressure on system memory. This may be desirable in many cases: for example a system could be designed with a small CPU connected to a PCIe switch by a small number of lanes which would maximize the number of lanes available to connect to NVMe devices. The code is designed to only utilize the p2pmem device if all the devices involved in a transfer are behind the same PCI bridge. This is because we have no way of knowing whether peer-to-peer routing between PCIe Root Ports is supported (PCIe r4.0, sec 1.3.1). Additionally, the benefits of P2P transfers that go through the RC is limited to only reducing DRAM usage and, in some cases, coding convenience. The PCI-SIG may be exploring adding a new capability bit to advertise whether this is possible for future hardware. This commit includes significant rework and feedback from Christoph Hellwig. Signed-off-by: Christoph Hellwig Signed-off-by: Logan Gunthorpe [bhelgaas: fold in fix from Keith Busch : https://lore.kernel.org/linux-pci/20181012155920.15418-1-keith.busch@intel.com, to address comment from Dan Carpenter , fold in https://lore.kernel.org/linux-pci/20181017160510.17926-1-logang@deltatee.com] Signed-off-by: Bjorn Helgaas

PCI: Initialize endpoint library before controllers

2018-06-26T20:37:37+00:00

The endpoint library must be initialized before its users, which are in drivers/pci/controllers. The endpoint initialization currently depends on link order. This corrects a kernel crash when loading the Cadence EP driver, since it calls devm_pci_epc_create() and this is only valid once the endpoint library has been initialized. Fixes: 6e0832fa432e ("PCI: Collect all native drivers under drivers/pci/controller/") Signed-off-by: Alan Douglas Signed-off-by: Bjorn Helgaas

PCI: Collect all native drivers under drivers/pci/controller/

2018-06-08T12:50:11+00:00

Native PCI drivers for root complex devices were originally all in drivers/pci/host/. Some of these devices can also be operated in endpoint mode. Drivers for endpoint mode didn't seem to fit in the "host" directory, so we put both the root complex and endpoint drivers in per-device directories, e.g., drivers/pci/dwc/, drivers/pci/cadence/, etc. These per-device directories contain trivial Kconfig and Makefiles and clutter drivers/pci/. Make a new drivers/pci/controllers/ directory and collect all the device-specific drivers there. No functional change intended. Link: https://lkml.kernel.org/r/1520304202-232891-1-git-send-email-shawn.lin@rock-chips.com Signed-off-by: Shawn Lin [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas

PCI/IOV: Add pci-pf-stub driver for PFs that only enable VFs

2018-04-24T21:47:16+00:00

Some SR-IOV PF devices provide no functionality other than acting as a means of enabling VFs. For these devices, we want to enable the VFs and assign them to guest virtual machines, but there's no need to have a driver for the PF itself. Add a new pci-pf-stub driver to claim those PF devices and provide the generic VF enable functionality. An administrator can use the sysfs "sriov_numvfs" file to enable VFs, then assign them to guests. For now I only have one example ID provided by Amazon in terms of devices that require this functionality. The general idea is that in the future we will see other devices added as vendors come up with devices where the PF is more or less just a lightweight shim used to allocate VFs. Signed-off-by: Alexander Duyck [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas Reviewed-by: Greg Rose Reviewed-by: Christoph Hellwig

PCI: Tidy Makefiles

2018-03-19T19:20:41+00:00

Indent things so they line up neatly and remove extra blank lines and superfluous comments. No functional change intended. Signed-off-by: Bjorn Helgaas