kernel.git/drivers/pci/bus.c, branch linux-4.19.y

PCI: Add device even if driver attach failed

2020-08-21T09:05:29Z

commit 2194bc7c39610be7cabe7456c5f63a570604f015 upstream. device_attach() returning failure indicates a driver error while trying to probe the device. In such a scenario, the PCI device should still be added in the system and be visible to the user. When device_attach() fails, merely warn about it and keep the PCI device in the system. This partially reverts ab1a187bba5c ("PCI: Check device_attach() return value always"). Link: https://lore.kernel.org/r/20200706233240.3245512-1-rajatja@google.com Signed-off-by: Rajat Jain Signed-off-by: Bjorn Helgaas Reviewed-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org # v4.6+ Signed-off-by: Greg Kroah-Hartman

PCI: Fix is_added/is_busmaster race condition

2018-07-31T16:27:54Z

When a PCI device is detected, pdev->is_added is set to 1 and proc and sysfs entries are created. When the device is removed, pdev->is_added is checked for one and then device is detached with clearing of proc and sys entries and at end, pdev->is_added is set to 0. is_added and is_busmaster are bit fields in pci_dev structure sharing same memory location. A strange issue was observed with multiple removal and rescan of a PCIe NVMe device using sysfs commands where is_added flag was observed as zero instead of one while removing device and proc,sys entries are not cleared. This causes issue in later device addition with warning message "proc_dir_entry" already registered. Debugging revealed a race condition between the PCI core setting the is_added bit in pci_bus_add_device() and the NVMe driver reset work-queue setting the is_busmaster bit in pci_set_master(). As these fields are not handled atomically, that clears the is_added bit. Move the is_added bit to a separate private flag variable and use atomic functions to set and retrieve the device addition state. This avoids the race because is_added no longer shares a memory location with is_busmaster. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200283 Signed-off-by: Hari Vyas Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Acked-by: Michael Ellerman

PCI: remove CONFIG_PCI_BUS_ADDR_T_64BIT

2018-05-09T04:57:18Z

This symbol is now always identical to CONFIG_ARCH_DMA_ADDR_T_64BIT, so remove it. Signed-off-by: Christoph Hellwig Acked-by: Bjorn Helgaas

PCI: Tidy comments

2018-03-19T19:20:43Z

Remove pointless comments that tell us the file name, remove blank line comments, follow multi-line comment conventions. No functional change intended. Signed-off-by: Bjorn Helgaas

Merge branch 'pci/spdx' into next

2018-02-01T17:40:07Z

* pci/spdx: PCI: Add SPDX GPL-2.0+ to replace implicit GPL v2 or later statement PCI: Add SPDX GPL-2.0+ to replace GPL v2 or later boilerplate PCI: Add SPDX GPL-2.0 to replace COPYING boilerplate PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate PCI: Add SPDX GPL-2.0 when no license was specified

PCI: Add SPDX GPL-2.0 when no license was specified

2018-01-26T17:45:16Z

b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to files with no license") added SPDX GPL-2.0 to several PCI files that previously contained no license information. Add SPDX GPL-2.0 to all other PCI files that did not contain any license information and hence were under the default GPL version 2 license of the kernel. Signed-off-by: Bjorn Helgaas Reviewed-by: Greg Kroah-Hartman

PCI: Add wrappers for dev_printk()

2018-01-18T18:55:24Z

Add PCI-specific dev_printk() wrappers and use them to simplify the code slightly. No functional change intended. Signed-off-by: Frederick Lawler [bhelgaas: squash into one patch] Signed-off-by: Bjorn Helgaas

PCI: Autosense device removal in pci_bridge_d3_update()

2016-11-18T00:44:56Z

The algorithm to update the flag indicating whether a bridge may go to D3 makes a few optimizations based on whether the update was caused by the removal of a device on the one hand, versus the addition of a device or the change of its D3cold flags on the other hand. The information whether the update pertains to a removal is currently passed in by the caller, but the function may as well determine that itself by examining the device in question, thereby allowing for a considerable simplification and reduction of the code. Out of several options to determine removal, I've chosen the function device_is_registered() because it's cheap: It merely returns the dev->kobj.state_in_sysfs flag. That flag is set through device_add() when the root bus is scanned and cleared through device_remove(). The call to pci_bridge_d3_update() happens after each of these calls, respectively, so the ordering is correct. No functional change intended. Tested-by: Mika Westerberg Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki

Merge branches 'pci/demodularize-hosts' and 'pci/host-request-windows' into next

2016-08-01T17:23:57Z

* pci/demodularize-hosts: PCI: xgene: Make explicitly non-modular PCI: thunder-pem: Make explicitly non-modular PCI: thunder-ecam: Make explicitly non-modular PCI: tegra: Make explicitly non-modular PCI: rcar-gen2: Make explicitly non-modular PCI: rcar: Make explicitly non-modular PCI: mvebu: Make explicitly non-modular PCI: layerscape: Make explicitly non-modular PCI: keystone: Make explicitly non-modular PCI: hisi: Make explicitly non-modular PCI: generic: Make explicitly non-modular PCI: designware-plat: Make it explicitly non-modular PCI: artpec6: Make explicitly non-modular PCI: armada8k: Make explicitly non-modular PCI: artpec: Add PCI_MSI_IRQ_DOMAIN dependency PCI: artpec: Add Axis ARTPEC-6 PCIe controller driver PCI: Add DT binding for Axis ARTPEC-6 PCIe controller PCI: generic: Select IRQ_DOMAIN * pci/host-request-windows: PCI: versatile: Simplify host bridge window iteration PCI: versatile: Request host bridge window resources with core function PCI: tegra: Request host bridge window resources with core function PCI: tegra: Remove top-level resource from hierarchy PCI: rcar: Simplify host bridge window iteration PCI: rcar: Request host bridge window resources with core function PCI: rcar Gen2: Request host bridge window resources PCI: rcar: Drop gen2 dummy I/O port region ARM: Make PCI I/O space optional PCI: mvebu: Request host bridge window resources with core function PCI: generic: Simplify host bridge window iteration PCI: generic: Request host bridge window resources with core function PCI: altera: Simplify host bridge window iteration PCI: altera: Request host bridge window resources with core function PCI: xilinx-nwl: Use dev_printk() when possible PCI: xilinx-nwl: Request host bridge window resources PCI: xilinx-nwl: Free bridge resource list on failure PCI: xilinx: Request host bridge window resources PCI: xilinx: Free bridge resource list on failure PCI: xgene: Request host bridge window resources PCI: xgene: Free bridge resource list on failure PCI: iproc: Request host bridge window resources PCI: designware: Simplify host bridge window iteration PCI: designware: Request host bridge window resources PCI: designware: Free bridge resource list on failure PCI: Add devm_request_pci_bus_resources()

PCI: Put PCIe ports into D3 during suspend

2016-06-13T19:57:36Z

Currently the Linux PCI core does not touch power state of PCI bridges and PCIe ports when system suspend is entered. Leaving them in D0 consumes power unnecessarily and may prevent the CPU from entering deeper C-states. With recent PCIe hardware we can power down the ports to save power given that we take into account few restrictions: - The PCIe port hardware is recent enough, starting from 2015. - Devices connected to PCIe ports are effectively in D3cold once the port is transitioned to D3 (the config space is not accessible anymore and the link may be powered down). - Devices behind the PCIe port need to be allowed to transition to D3cold and back. There is a way both drivers and userspace can forbid this. - If the device behind the PCIe port is capable of waking the system it needs to be able to do so from D3cold. This patch adds a new flag to struct pci_device called 'bridge_d3'. This flag is set and cleared by the PCI core whenever there is a change in power management state of any of the devices behind the PCIe port. When system later on is suspended we only need to check this flag and if it is true transition the port to D3 otherwise we leave it in D0. Also provide override mechanism via command line parameter "pcie_port_pm=[off|force]" that can be used to disable or enable the feature regardless of the BIOS manufacturing date. Tested-by: Lukas Wunner Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki