summaryrefslogtreecommitdiffstats
path: root/drivers/pci/pci.c
AgeCommit message (Collapse)Author
2016-12-12Merge branch 'pci/virtualization' into nextBjorn Helgaas
* pci/virtualization: PCI: Add comments about ROM BAR updating PCI: Decouple IORESOURCE_ROM_ENABLE and PCI_ROM_ADDRESS_ENABLE PCI: Remove pci_resource_bar() and pci_iov_resource_bar() PCI: Don't update VF BARs while VF memory space is enabled PCI: Separate VF BAR updates from standard BAR updates PCI: Update BARs using property bits appropriate for type PCI: Ignore BAR updates on virtual functions PCI: Do any VF BAR updates before enabling the BARs PCI: Support INTx masking on ConnectX-4 with firmware x.14.1100+ PCI: Convert Mellanox broken INTx quirks to be for listed devices only PCI: Convert broken INTx masking quirks from HEADER to FINAL net/mlx4_core: Use device ID defines PCI: Add Mellanox device IDs
2016-11-29PCI: Remove pci_resource_bar() and pci_iov_resource_bar()Bjorn Helgaas
pci_std_update_resource() only deals with standard BARs, so we don't have to worry about the complications of VF BARs in an SR-IOV capability. Compute the BAR address inline and remove pci_resource_bar(). That makes pci_iov_resource_bar() unused, so remove that as well. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
2016-11-28PCI: Ignore BAR updates on virtual functionsBjorn Helgaas
VF BARs are read-only zero, so updating VF BARs will not have any effect. See the SR-IOV spec r1.1, sec 3.4.1.11. We already ignore these updates because of 70675e0b6a1a ("PCI: Don't try to restore VF BARs"); this merely restructures it slightly to make it easier to split updates for standard and SR-IOV BARs. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
2016-11-17PCI: pciehp: Add runtime PM support for PCIe hotplug portsLukas Wunner
Linux 4.8 added support for runtime suspending PCIe ports to D3hot with commit 006d44e49a25 ("PCI: Add runtime PM support for PCIe ports"), but excluded hotplug ports. Those are now afforded runtime PM by the present commit. Hotplug ports require a few extra considerations: - The configuration space of the port remains accessible in D3hot, so all the functions to read or modify the Slot Status and Slot Control registers need not be modified. Even turning on slot power doesn't seem to require the port to be in D0, at least the PCIe spec doesn't say so and I confirmed that by testing with a Thunderbolt controller. - However D0 is required to access devices on the secondary bus. This happens in pciehp_check_link_status() and pciehp_configure_device() (both called from board_added()) and in pciehp_unconfigure_device() (called from remove_board()), so acquire a runtime PM ref for their invocation. - The hotplug port stays active as long as it has active children. If all hotplugged devices below the port runtime suspend, the port is allowed to runtime suspend as well. Plug and unplug detection continues to work in D3hot. - Hotplug interrupts are delivered in-band, so while the hotplug port itself is allowed to go to D3hot, its parent ports must stay in D0 for interrupts to come through. Add a corresponding restriction to pci_dev_check_d3cold(). - Runtime PM may only be allowed if the hotplug port is handled natively by the OS. On ACPI systems, the port may alternatively be handled by the firmware and things break if the OS puts the port into D3 behind the firmware's back: E.g. Thunderbolt hotplug ports on non-Macs are handled by Intel's firmware in System Management Mode and the firmware is known to access devices on the port's secondary bus without checking first if the port is in D0: https://bugzilla.kernel.org/show_bug.cgi?id=53811 Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> CC: Mika Westerberg <mika.westerberg@linux.intel.com>
2016-11-17PCI: Unfold conditions to block runtime PM on PCIe portsLukas Wunner
The conditions to block D3 on parent ports are currently condensed into a single expression in pci_dev_check_d3cold(). Upcoming commits will add further conditions for hotplug ports, making this expression fairly large and impenetrable. Unfold the conditions to maintain readability when they are amended. No functional change intended. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Mika Westerberg <mika.westerberg@linux.intel.com> CC: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-17PCI: Consolidate conditions to allow runtime PM on PCIe portsLukas Wunner
The conditions to allow runtime PM on PCIe ports are currently spread across two different files: The condition relating to hotplug ports is located in portdrv_pci.c whereas all other conditions are located in pci.c. Consolidate all conditions in a single place in pci.c, thus making it easier to follow the logic and amend conditions down the road. Note that the condition relating to hotplug ports is inserted *before* the condition relating to the "pcie_port_pm=force" command line option, so runtime PM is not afforded to hotplug ports even if this option is given. That's exactly how the code behaved up until now. If this is not desired, the ordering of the conditions can simply be reversed. No functional change intended. Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-17PCI: Activate runtime PM on a PCIe port only if it can suspendLukas Wunner
Currently pcie_portdrv_probe() activates runtime PM on a PCIe port even if it will never actually suspend because the BIOS is too old or the "pcie_port_pm=off" option was specified on the kernel command line. A few CPU cycles can be saved by not activating runtime PM at all in these cases, because rpm_idle() and rpm_suspend() will bail out right at the beginning when calling rpm_check_suspend_allowed(), instead of carrying out various locking and assignments, invoking rpm_callback(), getting back -EBUSY and rolling everything back. The conditions checked in pci_bridge_d3_possible() are all static, they never change during uptime of the system, hence it's safe to call this to determine if runtime PM should be activated. No functional change intended. Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-17PCI: Speed up algorithm in pci_bridge_d3_update()Lukas Wunner
After a device has been added, removed or had its D3cold attributes changed, we recheck whether its parent bridge may runtime suspend to D3hot with pci_bridge_d3_update(). The most naive algorithm would be to iterate over the bridge's children and check if any of them are blocking D3. The function already tries to be a bit smarter than that by first checking the device that was changed. If this device already blocks D3 on the bridge, then walking over all the other children can be skipped. A drawback of this approach is that if the device is *not* blocking D3, it will be checked a second time by pci_walk_bus(). But that's cheap and is outweighed by the performance gain of potentially skipping pci_walk_bus() altogether. The algorithm can be optimized further by taking into account if D3 is currently allowed for the bridge, as shown in the following truth table: (a) remove && bridge_d3: D3 is currently allowed for the bridge and removing one of its children won't change that. No action necessary. (b) remove && !bridge_d3: D3 may now be allowed for the bridge if the removed child was the only one blocking it. Check all its siblings to verify that. (c) !remove && bridge_d3: D3 may now be disallowed but this can only be caused by the added/changed child, not any of its siblings. Check only that single device. (d) !remove && !bridge_d3: D3 may now be allowed for the bridge if the changed child was the only one blocking it. Check all its siblings to verify that. By checking beforehand if the changed child is blocking D3, we may be able to skip checking its siblings. Currently we do not special-case option (a) and in case of option (c) we gratuitously call pci_walk_bus(). Speed up the algorithm by adding these optimizations. Reword the comments a bit in an attempt to improve clarity. No functional change intended. Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-17PCI: Autosense device removal in pci_bridge_d3_update()Lukas Wunner
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 <mika.westerberg@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-17PCI: Don't acquire ref on parent in pci_bridge_d3_update()Lukas Wunner
This function is always called with an existing pci_dev struct, which holds a reference on the pci_bus struct it resides on, which in turn holds a reference on pci_bus->bridge, which is the pci_dev's parent. Hence there's no need to acquire an additional ref on the parent. More specifically, the pci_dev exists until pci_destroy_dev() drops the final reference on it, so all calls to pci_bridge_d3_update() must be finished before that. It is arguably the caller's responsibility to ensure that it doesn't call pci_bridge_d3_update() with a pci_dev that might suddenly disappear, but in any case the existing callers are all safe: - The call in pci_destroy_dev() happens before the call to put_device(). - The call in pci_bus_add_device() is synchronized with pci_destroy_dev() using pci_lock_rescan_remove(). - The calls to pci_d3cold_disable() from the xhci and nouveau drivers are safe because a ref on the pci_dev is held as long as it's bound to a driver. - The calls to pci_d3cold_enable() / pci_d3cold_disable() when modifying the sysfs "d3cold_allowed" entry are also safe because kernfs_drain() waits for existing sysfs users to finish before removing the entry, and pci_destroy_dev() is called way after that. No functional change intended. Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-11PCI: Check for PME in targeted sleep stateAlan Stern
One some systems, the firmware does not allow certain PCI devices to be put in deep D-states. This can cause problems for wakeup signalling, if the device does not support PME# in the deepest allowed suspend state. For example, Pierre reports that on his system, ACPI does not permit his xHCI host controller to go into D3 during runtime suspend -- but D3 is the only state in which the controller can generate PME# signals. As a result, the controller goes into runtime suspend but never wakes up, so it doesn't work properly. USB devices plugged into the controller are never detected. If the device relies on PME# for wakeup signals but is not capable of generating PME# in the target state, the PCI core should accurately report that it cannot do wakeup from runtime suspend. This patch modifies the pci_dev_run_wake() routine to add this check. Reported-by: Pierre de Villemereuil <flyos@mailoo.org> Tested-by: Pierre de Villemereuil <flyos@mailoo.org> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> CC: stable@vger.kernel.org CC: Lukas Wunner <lukas@wunner.de>
2016-10-07Merge tag 'pci-v4.9-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "Summary of PCI changes for the v4.9 merge window: Enumeration: - microblaze: Add multidomain support for procfs (Bharat Kumar Gogada) Resource management: - Ignore requested alignment for PROBE_ONLY and fixed resources (Yongji Xie) - Ignore requested alignment for VF BARs (Yongji Xie) PCI device hotplug: - Make core explicitly non-modular (Paul Gortmaker) PCIe native device hotplug: - Rename pcie_isr() locals for clarity (Bjorn Helgaas) - Return IRQ_NONE when we can't read interrupt status (Bjorn Helgaas) - Remove unnecessary guard (Bjorn Helgaas) - Clean up dmesg "Slot(%s)" messages (Bjorn Helgaas) - Remove useless pciehp_get_latch_status() calls (Bjorn Helgaas) - Clear attention LED on device add (Keith Busch) - Allow exclusive userspace control of indicators (Keith Busch) - Process all hotplug events before looking for new ones (Mayurkumar Patel) - Don't re-read Slot Status when queuing hotplug event (Mayurkumar Patel) - Don't re-read Slot Status when handling surprise event (Mayurkumar Patel) - Make explicitly non-modular (Paul Gortmaker) Power management: - Afford direct-complete to devices with non-standard PM (Lukas Wunner) - Query platform firmware for device power state (Lukas Wunner) - Recognize D3cold in pci_update_current_state() (Lukas Wunner) - Avoid unnecessary resume after direct-complete (Lukas Wunner) - Make explicitly non-modular (Paul Gortmaker) Virtualization: - Mark Atheros AR9580 to avoid bus reset (Maik Broemme) - Check for pci_setup_device() failure in pci_iov_add_virtfn() (Po Liu) MSI: - Enable PCI_MSI_IRQ_DOMAIN support for ARC (Joao Pinto) AER: - Remove aerdriver.nosourceid kernel parameter (Bjorn Helgaas) - Remove aerdriver.forceload kernel parameter (Bjorn Helgaas) - Fix aer_probe() kernel-doc comment (Cao jin) - Add bus flag to skip source ID matching (Jon Derrick) - Avoid memory allocation in interrupt handling path (Jon Derrick) - Cache capability position (Keith Busch) - Make explicitly non-modular (Paul Gortmaker) - Remove duplicate AER severity translation (Tyler Baicar) - Send correct severity to calculate AER severity (Tyler Baicar) Precision Time Measurement: - Add Precision Time Measurement (PTM) support (Jonathan Yong) - Add PTM clock granularity information (Bjorn Helgaas) - Add pci_enable_ptm() for drivers to enable PTM on endpoints (Bjorn Helgaas) Generic host bridge driver: - Fix pci_remap_iospace() failure path (Lorenzo Pieralisi) - Make explicitly non-modular (Paul Gortmaker) Altera host bridge driver: - Remove redundant platform_get_resource() return value check (Bjorn Helgaas) - Poll for link training status after retraining the link (Ley Foon Tan) - Rework config accessors for use without a struct pci_bus (Ley Foon Tan) - Move retrain from fixup to altera_pcie_host_init() (Ley Foon Tan) - Make MSI explicitly non-modular (Paul Gortmaker) - Make explicitly non-modular (Paul Gortmaker) - Relax device number checking to allow SR-IOV (Po Liu) ARM Versatile host bridge driver: - Fix pci_remap_iospace() failure path (Lorenzo Pieralisi) Axis ARTPEC-6 host bridge driver: - Drop __init from artpec6_add_pcie_port() (Niklas Cassel) Freescale i.MX6 host bridge driver: - Make explicitly non-modular (Paul Gortmaker) Intel VMD host bridge driver: - Add quirk for AER to ignore source ID (Jon Derrick) - Allocate IRQ lists with correct MSI-X count (Jon Derrick) - Convert to use pci_alloc_irq_vectors() API (Jon Derrick) - Eliminate vmd_vector member from list type (Jon Derrick) - Eliminate index member from IRQ list (Jon Derrick) - Synchronize with RCU freeing MSI IRQ descs (Keith Busch) - Request userspace control of PCIe hotplug indicators (Keith Busch) - Move VMD driver to drivers/pci/host (Keith Busch) Marvell Aardvark host bridge driver: - Fix pci_remap_iospace() failure path (Lorenzo Pieralisi) - Remove redundant dev_err call in advk_pcie_probe() (Wei Yongjun) Microsoft Hyper-V host bridge driver: - Use zero-length array in struct pci_packet (Dexuan Cui) - Use pci_function_description[0] in struct definitions (Dexuan Cui) - Remove the unused 'wrk' in struct hv_pcibus_device (Dexuan Cui) - Handle vmbus_sendpacket() failure in hv_compose_msi_msg() (Dexuan Cui) - Handle hv_pci_generic_compl() error case (Dexuan Cui) - Use list_move_tail() instead of list_del() + list_add_tail() (Wei Yongjun) NVIDIA Tegra host bridge driver: - Fix pci_remap_iospace() failure path (Lorenzo Pieralisi) - Remove redundant _data suffix (Thierry Reding) - Use of_device_get_match_data() (Thierry Reding) Qualcomm host bridge driver: - Make explicitly non-modular (Paul Gortmaker) Renesas R-Car host bridge driver: - Consolidate register space lookup and ioremap (Bjorn Helgaas) - Don't disable/unprepare clocks on prepare/enable failure (Geert Uytterhoeven) - Add multi-MSI support (Grigory Kletsko) - Fix pci_remap_iospace() failure path (Lorenzo Pieralisi) - Fix some checkpatch warnings (Sergei Shtylyov) - Try increasing PCIe link speed to 5 GT/s at boot (Sergei Shtylyov) Rockchip host bridge driver: - Add DT bindings for Rockchip PCIe controller (Shawn Lin) - Add Rockchip PCIe controller support (Shawn Lin) - Improve the deassert sequence of four reset pins (Shawn Lin) - Fix wrong transmitted FTS count (Shawn Lin) - Increase the Max Credit update interval (Rajat Jain) Samsung Exynos host bridge driver: - Make explicitly non-modular (Paul Gortmaker) ST Microelectronics SPEAr13xx host bridge driver: - Make explicitly non-modular (Paul Gortmaker) Synopsys DesignWare host bridge driver: - Return data directly from dw_pcie_readl_rc() (Bjorn Helgaas) - Exchange viewport of `MEMORYs' and `CFGs/IOs' (Dong Bo) - Check LTSSM training bit before deciding link is up (Jisheng Zhang) - Move link wait definitions to .c file (Joao Pinto) - Wait for iATU enable (Joao Pinto) - Add iATU Unroll feature (Joao Pinto) - Fix pci_remap_iospace() failure path (Lorenzo Pieralisi) - Make explicitly non-modular (Paul Gortmaker) - Relax device number checking to allow SR-IOV (Po Liu) - Keep viewport fixed for IO transaction if num_viewport > 2 (Pratyush Anand) - Remove redundant platform_get_resource() return value check (Wei Yongjun) TI DRA7xx host bridge driver: - Make explicitly non-modular (Paul Gortmaker) TI Keystone host bridge driver: - Propagate request_irq() failure (Wei Yongjun) Xilinx AXI host bridge driver: - Keep both legacy and MSI interrupt domain references (Bharat Kumar Gogada) - Clear interrupt register for invalid interrupt (Bharat Kumar Gogada) - Clear correct MSI set bit (Bharat Kumar Gogada) - Dispose of MSI virtual IRQ (Bharat Kumar Gogada) - Make explicitly non-modular (Paul Gortmaker) - Relax device number checking to allow SR-IOV (Po Liu) Xilinx NWL host bridge driver: - Expand error logging (Bharat Kumar Gogada) - Enable all MSI interrupts using MSI mask (Bharat Kumar Gogada) - Make explicitly non-modular (Paul Gortmaker) Miscellaneous: - Drop CONFIG_KEXEC_CORE ifdeffery (Lukas Wunner) - portdrv: Make explicitly non-modular (Paul Gortmaker) - Make DPC explicitly non-modular (Paul Gortmaker)" * tag 'pci-v4.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (105 commits) x86/PCI: VMD: Move VMD driver to drivers/pci/host PCI: rockchip: Fix wrong transmitted FTS count PCI: rockchip: Improve the deassert sequence of four reset pins PCI: rockchip: Increase the Max Credit update interval PCI: rcar: Try increasing PCIe link speed to 5 GT/s at boot PCI/AER: Fix aer_probe() kernel-doc comment PCI: Ignore requested alignment for VF BARs PCI: Ignore requested alignment for PROBE_ONLY and fixed resources PCI: Avoid unnecessary resume after direct-complete PCI: Recognize D3cold in pci_update_current_state() PCI: Query platform firmware for device power state PCI: Afford direct-complete to devices with non-standard PM PCI/AER: Cache capability position PCI/AER: Avoid memory allocation in interrupt handling path x86/PCI: VMD: Request userspace control of PCIe hotplug indicators PCI: pciehp: Allow exclusive userspace control of indicators ACPI / APEI: Send correct severity to calculate AER severity PCI/AER: Remove duplicate AER severity translation x86/PCI: VMD: Synchronize with RCU freeing MSI IRQ descs x86/PCI: VMD: Eliminate index member from IRQ list ...
2016-10-03Merge branch 'pci/resource' into nextBjorn Helgaas
* pci/resource: PCI: Ignore requested alignment for VF BARs PCI: Ignore requested alignment for PROBE_ONLY and fixed resources
2016-09-28PCI: Ignore requested alignment for VF BARsYongji Xie
Resource allocation for VFs is done via the VF BARx registers in the PF's SR-IOV Capability, and the BARs in the VFs themselves are read-only zeros (see SR-IOV spec r1.1, secs 3.3.14 and 3.4.1.11). Even though the actual VF BARs are read-only zeros, the VF dev->resource[] structs describe the space allocated for the VF (this is a piece of the space described by the VF BARx register in the PF's SR-IOV capability). It's meaningless to request additional alignment for a VF: the VF BAR alignment is completely determined by the alignment of the VF BARx in the PF and the size of the VF BAR. Ignore the user's alignment requests for VF devices. Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-09-28PCI: Ignore requested alignment for PROBE_ONLY and fixed resourcesYongji Xie
Users may request additional alignment of PCI resources, e.g., to align BARs on page boundaries so they can be shared with guests via VFIO. This of course may require reallocation if firmware has already assigned the BARs with smaller alignments. If the platform has requested PCI_PROBE_ONLY, we should never change any PCI BARs, so we can't provide any additional alignment. Also, if a BAR is marked as IORESOURCE_PCI_FIXED, e.g., for PCI Enhanced Allocation or if the firmware depends on the current BAR value, we can't change the alignment. In these cases, log a message and ignore the user's alignment requests. [bhelgaas: changelog, use goto to simplify PCI_PROBE_ONLY check] Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-09-28PCI: Recognize D3cold in pci_update_current_state()Lukas Wunner
Whenever a device is resumed or its power state is changed using the platform, its new power state is read from the PM Control & Status Register and cached in pci_dev->current_state by calling pci_update_current_state(). If the device is in D3cold, reading from config space typically results in a fabricated "all ones" response. But if it's in D3hot, the two bits representing the power state in the PMCSR are *also* set to 1. Thus D3hot and D3cold are not discernible by just reading the PMCSR. To account for this, pci_update_current_state() uses two workarounds: - When transitioning to D3cold using pci_platform_power_transition(), the new power state is set blindly by pci_update_current_state(), i.e. without verifying that the device actually *is* in D3cold. This is achieved by setting the "state" argument to PCI_D3cold. The "state" argument was originally intended to convey the new state in case the device doesn't have the PM capability. It is *also* used to convey the device state if the PM capability is present and the new state is D3cold, but this was never explained in the kerneldoc. - Once the current_state is set to D3cold, further invocations of pci_update_current_state() will blindly assume that the device is still in D3cold and leave the current_state unmodified. To get out of this impasse, the current_state has to be set directly, typically by calling pci_raw_set_power_state() or pci_enable_device(). It would be desirable if pci_update_current_state() could reliably detect D3cold by itself. That would allow us to do away with these workarounds, and it would allow for a smarter, more energy conserving runtime resume strategy after system sleep: Currently devices which utilize direct_complete are mandatorily runtime resumed in their ->complete stage. This can be avoided if their power state after system sleep is the same as before, but it requires a mechanism to detect the power state reliably. We've just gained the ability to query the platform firmware for its opinion on the device's power state. On platforms conforming to ACPI 4.0 or newer, this allows recognition of D3cold. Pre-4.0 platforms lack _PR3 and therefore the deepest power state that will ever be reported is D3hot, even though the device may actually be in D3cold. To detect D3cold in those cases, accessibility of the vendor ID in config space is probed using pci_device_is_present(). This also works for devices which are not platform-power-manageable at all, but can be suspended to D3cold using a nonstandard mechanism (e.g. some hybrid graphics laptops or Thunderbolt on the Mac). Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-28PCI: Query platform firmware for device power stateLukas Wunner
Usually the most accurate way to determine a PCI device's power state is to read its PM Control & Status Register. There are two cases however when this is not an option: If the device doesn't have the PM capability at all, or if it is in D3cold (in which case its config space is inaccessible). In both cases, we can alternatively query the platform firmware for its opinion on the device's power state. To facilitate this, augment struct pci_platform_pm_ops with a ->get_power callback and implement it for acpi_pci_platform_pm (the only pci_platform_pm_ops existing so far). It is used by a forthcoming commit to let pci_update_current_state() recognize D3cold. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-28PCI: Afford direct-complete to devices with non-standard PMLukas Wunner
There are devices not power-manageable by the platform, but still able to runtime suspend to D3cold with a non-standard mechanism. One example is laptop hybrid graphics where the discrete GPU and its built-in HDA controller are power-managed either with a _DSM (AMD PowerXpress, Nvidia Optimus) or a separate gmux controller (MacBook Pro). Another example is Thunderbolt on Macs which is power-managed with custom ACPI methods. When putting the system to sleep, we currently handle such devices improperly by transitioning them from D3cold to D3hot (the default power state defined at the top of pci_target_state()). This wastes energy and prolongs the suspend sequence (powering up the Thunderbolt controller takes 2 seconds). Avoid that by assuming that a non-standard PM mechanism is at work if the device is not platform-power-manageable but currently in D3cold. If the device is wakeup enabled, we might still have to wake it up from D3cold if PME cannot be signaled from that power state. The check for devices without PM capability comes before the check for D3cold since such devices could in theory also be powered down by non-standard means and should then be afforded direct-complete as well. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-17PCI: Add pci_find_resource()Mika Westerberg
Add a new helper function pci_find_resource() that can be used to find out whether a given resource (for example from a child device) is contained within given PCI device's standard resources. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-02Merge tag 'pci-v4.8-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "Highlights: - ARM64 support for ACPI host bridges - new drivers for Axis ARTPEC-6 and Marvell Aardvark - new pci_alloc_irq_vectors() interface for MSI-X, MSI, legacy INTx - pci_resource_to_user() cleanup (more to come) Detailed summary: Enumeration: - Move ecam.h to linux/include/pci-ecam.h (Jayachandran C) - Add parent device field to ECAM struct pci_config_window (Jayachandran C) - Add generic MCFG table handling (Tomasz Nowicki) - Refactor pci_bus_assign_domain_nr() for CONFIG_PCI_DOMAINS_GENERIC (Tomasz Nowicki) - Factor DT-specific pci_bus_find_domain_nr() code out (Tomasz Nowicki) Resource management: - Add devm_request_pci_bus_resources() (Bjorn Helgaas) - Unify pci_resource_to_user() declarations (Bjorn Helgaas) - Implement pci_resource_to_user() with pcibios_resource_to_bus() (microblaze, powerpc, sparc) (Bjorn Helgaas) - Request host bridge window resources (designware, iproc, rcar, xgene, xilinx, xilinx-nwl) (Bjorn Helgaas) - Make PCI I/O space optional on ARM32 (Bjorn Helgaas) - Ignore write combining when mapping I/O port space (Bjorn Helgaas) - Claim bus resources on MIPS PCI_PROBE_ONLY set-ups (Bjorn Helgaas) - Remove unicore32 pci=firmware command line parameter handling (Bjorn Helgaas) - Support I/O resources when parsing host bridge resources (Jayachandran C) - Add helpers to request/release memory and I/O regions (Johannes Thumshirn) - Use pci_(request|release)_mem_regions (NVMe, lpfc, GenWQE, ethernet/intel, alx) (Johannes Thumshirn) - Extend pci=resource_alignment to specify device/vendor IDs (Koehrer Mathias (ETAS/ESW5)) - Add generic pci_bus_claim_resources() (Lorenzo Pieralisi) - Claim bus resources on ARM32 PCI_PROBE_ONLY set-ups (Lorenzo Pieralisi) - Remove ARM32 and ARM64 arch-specific pcibios_enable_device() (Lorenzo Pieralisi) - Add pci_unmap_iospace() to unmap I/O resources (Sinan Kaya) - Remove powerpc __pci_mmap_set_pgprot() (Yinghai Lu) PCI device hotplug: - Allow additional bus numbers for hotplug bridges (Keith Busch) - Ignore interrupts during D3cold (Lukas Wunner) Power management: - Enforce type casting for pci_power_t (Andy Shevchenko) - Don't clear d3cold_allowed for PCIe ports (Mika Westerberg) - Put PCIe ports into D3 during suspend (Mika Westerberg) - Power on bridges before scanning new devices (Mika Westerberg) - Runtime resume bridge before rescan (Mika Westerberg) - Add runtime PM support for PCIe ports (Mika Westerberg) - Remove redundant check of pcie_set_clkpm (Shawn Lin) Virtualization: - Add function 1 DMA alias quirk for Marvell 88SE9182 (Aaron Sierra) - Add DMA alias quirk for Adaptec 3805 (Alex Williamson) - Mark Atheros AR9485 and QCA9882 to avoid bus reset (Chris Blake) - Add ACS quirk for Solarflare SFC9220 (Edward Cree) MSI: - Fix PCI_MSI dependencies (Arnd Bergmann) - Add pci_msix_desc_addr() helper (Christoph Hellwig) - Switch msix_program_entries() to use pci_msix_desc_addr() (Christoph Hellwig) - Make the "entries" argument to pci_enable_msix() optional (Christoph Hellwig) - Provide sensible IRQ vector alloc/free routines (Christoph Hellwig) - Spread interrupt vectors in pci_alloc_irq_vectors() (Christoph Hellwig) Error Handling: - Bind DPC to Root Ports as well as Downstream Ports (Keith Busch) - Remove DPC tristate module option (Keith Busch) - Convert Downstream Port Containment driver to use devm_* functions (Mika Westerberg) Generic host bridge driver: - Select IRQ_DOMAIN (Arnd Bergmann) - Claim bus resources on PCI_PROBE_ONLY set-ups (Lorenzo Pieralisi) ACPI host bridge driver: - Add ARM64 acpi_pci_bus_find_domain_nr() (Tomasz Nowicki) - Add ARM64 ACPI support for legacy IRQs parsing and consolidation with DT code (Tomasz Nowicki) - Implement ARM64 AML accessors for PCI_Config region (Tomasz Nowicki) - Support ARM64 ACPI-based PCI host controller (Tomasz Nowicki) Altera host bridge driver: - Check link status before retrain link (Ley Foon Tan) - Poll for link up status after retraining the link (Ley Foon Tan) Axis ARTPEC-6 host bridge driver: - Add PCI_MSI_IRQ_DOMAIN dependency (Arnd Bergmann) - Add DT binding for Axis ARTPEC-6 PCIe controller (Niklas Cassel) - Add Axis ARTPEC-6 PCIe controller driver (Niklas Cassel) Intel VMD host bridge driver: - Use lock save/restore in interrupt enable path (Jon Derrick) - Select device dma ops to override (Keith Busch) - Initialize list item in IRQ disable (Keith Busch) - Use x86_vector_domain as parent domain (Keith Busch) - Separate MSI and MSI-X vector sharing (Keith Busch) Marvell Aardvark host bridge driver: - Add DT binding for the Aardvark PCIe controller (Thomas Petazzoni) - Add Aardvark PCI host controller driver (Thomas Petazzoni) - Add Aardvark PCIe support for Armada 3700 (Thomas Petazzoni) Microsoft Hyper-V host bridge driver: - Fix interrupt cleanup path (Cathy Avery) - Don't leak buffer in hv_pci_onchannelcallback() (Vitaly Kuznetsov) - Handle all pending messages in hv_pci_onchannelcallback() (Vitaly Kuznetsov) NVIDIA Tegra host bridge driver: - Program PADS_REFCLK_CFG* always, not just on legacy SoCs (Stephen Warren) - Program PADS_REFCLK_CFG* registers with per-SoC values (Stephen Warren) - Use lower-case hex consistently for register definitions (Thierry Reding) - Use generic pci_remap_iospace() rather than ARM32-specific one (Thierry Reding) - Stop setting pcibios_min_mem (Thierry Reding) Renesas R-Car host bridge driver: - Drop gen2 dummy I/O port region (Bjorn Helgaas) TI DRA7xx host bridge driver: - Fix return value in case of error (Christophe JAILLET) Xilinx AXI host bridge driver: - Fix return value in case of error (Christophe JAILLET) Miscellaneous: - Make bus_attr_resource_alignment static (Ben Dooks) - Include <asm/dma.h> for isa_dma_bridge_buggy (Ben Dooks) - MAINTAINERS: Add file patterns for PCI device tree bindings (Geert Uytterhoeven) - Make host bridge drivers explicitly non-modular (Paul Gortmaker)" * tag 'pci-v4.8-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (125 commits) 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: Add ACS quirk for Solarflare SFC9220 arm64: dts: marvell: Add Aardvark PCIe support for Armada 3700 PCI: aardvark: Add Aardvark PCI host controller driver dt-bindings: add DT binding for the Aardvark PCIe controller PCI: tegra: Program PADS_REFCLK_CFG* registers with per-SoC values ...
2016-08-01Merge branch 'pci/resource' into nextBjorn Helgaas
* pci/resource: unicore32/PCI: Remove pci=firmware command line parameter handling ARM/PCI: Remove arch-specific pcibios_enable_device() ARM64/PCI: Remove arch-specific pcibios_enable_device() MIPS/PCI: Claim bus resources on PCI_PROBE_ONLY set-ups ARM/PCI: Claim bus resources on PCI_PROBE_ONLY set-ups PCI: generic: Claim bus resources on PCI_PROBE_ONLY set-ups PCI: Add generic pci_bus_claim_resources() alx: Use pci_(request|release)_mem_regions ethernet/intel: Use pci_(request|release)_mem_regions GenWQE: Use pci_(request|release)_mem_regions lpfc: Use pci_(request|release)_mem_regions NVMe: Use pci_(request|release)_mem_regions PCI: Add helpers to request/release memory and I/O regions PCI: Extending pci=resource_alignment to specify device/vendor IDs sparc/PCI: Implement pci_resource_to_user() with pcibios_resource_to_bus() powerpc/pci: Implement pci_resource_to_user() with pcibios_resource_to_bus() microblaze/PCI: Implement pci_resource_to_user() with pcibios_resource_to_bus() PCI: Unify pci_resource_to_user() declarations microblaze/PCI: Remove useless __pci_mmap_set_pgprot() powerpc/pci: Remove __pci_mmap_set_pgprot() PCI: Ignore write combining when mapping I/O port space
2016-08-01Merge branches 'pci/aspm', 'pci/dpc', 'pci/hotplug', 'pci/misc', 'pci/msi', ↵Bjorn Helgaas
'pci/pm' and 'pci/virtualization' into next * pci/aspm: PCI/ASPM: Remove redundant check of pcie_set_clkpm * pci/dpc: PCI: Remove DPC tristate module option PCI: Bind DPC to Root Ports as well as Downstream Ports PCI: Fix whitespace in struct dpc_dev PCI: Convert Downstream Port Containment driver to use devm_* functions * pci/hotplug: PCI: Allow additional bus numbers for hotplug bridges * pci/misc: PCI: Include <asm/dma.h> for isa_dma_bridge_buggy PCI: Make bus_attr_resource_alignment static MAINTAINERS: Add file patterns for PCI device tree bindings PCI: Fix comment typo * pci/msi: PCI/MSI: irqchip: Fix PCI_MSI dependencies * pci/pm: PCI: pciehp: Ignore interrupts during D3cold PCI: Document connection between pci_power_t and hardware PM capability PCI: Add runtime PM support for PCIe ports ACPI / hotplug / PCI: Runtime resume bridge before rescan PCI: Power on bridges before scanning new devices PCI: Put PCIe ports into D3 during suspend PCI: Don't clear d3cold_allowed for PCIe ports PCI / PM: Enforce type casting for pci_power_t * pci/virtualization: PCI: Add ACS quirk for Solarflare SFC9220 PCI: Add DMA alias quirk for Adaptec 3805 PCI: Mark Atheros AR9485 and QCA9882 to avoid bus reset PCI: Add function 1 DMA alias quirk for Marvell 88SE9182
2016-07-25PCI: Allow additional bus numbers for hotplug bridgesKeith Busch
A user may hot add a switch requiring more than one bus to enumerate. This previously required a system reboot if BIOS did not sufficiently pad the bus resource, which they frequently don't do. Add a kernel parameter so a user can specify the minimum number of bus numbers to reserve for a hotplug bridge's subordinate buses so rebooting won't be necessary. The default is 1, which is equivalent to previous behavior. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-07-21PCI / PM: check all fields in pci_set_platform_pm()Andy Shevchenko
When assign new PCI platform PM operations check for all mandatory fields to prevent NULL pointer dereference. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-19PCI: Include <asm/dma.h> for isa_dma_bridge_buggyBen Dooks
At least on arm, <asm/dma.h> does not get included when building drivers/pci/pci.o. This causes the following build warning which can be fixed by including <asm/dma.h>: drivers/pci/pci.c:37:5: warning: symbol 'isa_dma_bridge_buggy' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-06-21PCI: Extending pci=resource_alignment to specify device/vendor IDsKoehrer Mathias (ETAS/ESW5)
Some uio-based PCI drivers, e.g., uio_cif do not work if the assigned PCI memory resources are not page aligned. By using the kernel option "pci=resource_alignment" it is possible to force single PCI boards to use page alignment for their memory resources. However, this is fairly cumbersome if several of these boards are in use as the specification of the cards has to be done via PCI bus/slot/function number which might change, e.g., by adding another board. Extend the kernel option "pci=resource_alignment" to allow specification of relevant devices via PCI device/vendor (and subdevice/subvendor) IDs. The specification of the devices via device/vendor is indicated by a leading string "pci:" as argument to "pci=resource_alignment". The format of the specification is pci:<vendor>:<device>[:<subvendor>:<subdevice>] Signed-off-by: Mathias Koehrer <mathias.koehrer@etas.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-06-13PCI: Put PCIe ports into D3 during suspendMika Westerberg
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 <lukas@wunner.de> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-10PCI: Make bus_attr_resource_alignment staticBen Dooks
The symbol bus_attr_resource_alignment is not exported or declared elsewhere, so make it static to fix the following warning: drivers/pci/pci.c:4900:1: warning: symbol 'bus_attr_resource_alignment' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-06-10ARM64: PCI: Add acpi_pci_bus_find_domain_nr()Tomasz Nowicki
Extend pci_bus_find_domain_nr() so it can find the domain from either: - ACPI, via the new acpi_pci_bus_find_domain_nr() interface, or - DT, via of_pci_bus_find_domain_nr() Note that this is only used for CONFIG_PCI_DOMAINS_GENERIC=y, so it does not affect x86 or ia64. [bhelgaas: changelog] Signed-off-by: Tomasz Nowicki <tn@semihalf.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-06-10PCI: Factor DT-specific pci_bus_find_domain_nr() code outTomasz Nowicki
pci_bus_find_domain_nr() retrieves the host bridge domain number in a DT-specific way. Rename it to of_pci_bus_find_domain_nr() to reflect that, so we can add a corresponding function for ACPI. [bhelgaas: changelog] Signed-off-by: Tomasz Nowicki <tn@semihalf.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2016-06-10PCI: Refactor pci_bus_assign_domain_nr() for CONFIG_PCI_DOMAINS_GENERICTomasz Nowicki
Instead of assigning bus->domain_nr inside pci_bus_assign_domain_nr(), return the domain and let the caller do the assignment. Rename pci_bus_assign_domain_nr() to pci_bus_find_domain_nr() to reflect this. No functional change intended. [bhelgaas: changelog] Signed-off-by: Tomasz Nowicki <tn@semihalf.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2016-06-10PCI: Add pci_unmap_iospace() to unmap I/O resourcesSinan Kaya
Add pci_unmap_iospace() to undo what pci_remap_iospace() did. This is needed to support hotplug removal of host bridges that use pci_remap_iospace(). [bhelgaas: changelog] Signed-off-by: Sinan Kaya <okaya@codeaurora.org> Signed-off-by: Tomasz Nowicki <tn@semihalf.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2016-05-17Merge branches 'pci/arm64' and 'pci/host-hv' into nextBjorn Helgaas
* pci/arm64: PCI, of: Move PCI I/O space management to PCI core code PCI: generic, thunder: Use generic ECAM API PCI: Provide common functions for ECAM mapping * pci/host-hv: PCI: hv: Add explicit barriers to config space access
2016-05-17Merge branches 'pci/hotplug' and 'pci/resource' into nextBjorn Helgaas
* pci/hotplug: PCI: Use cached copy of PCI_EXP_SLTCAP_HPC bit * pci/resource: PCI: Disable all BAR sizing for devices with non-compliant BARs x86/PCI: Mark Broadwell-EP Home Agent 1 as having non-compliant BARs PCI: Identify Enhanced Allocation (EA) BAR Equivalent resources in sysfs
2016-05-16PCI: Identify Enhanced Allocation (EA) BAR Equivalent resources in sysfsAlex Williamson
Resource flags are exposed to userspace via the sysfs "resource" file. lspci reads the sysfs file to determine resource properties. Add a "BAR Equivalent Indicator" flag so lspci can distinguish between [virtual] and [enhanced] resources. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sean O. Stalley <sean.stalley@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-05-12PCI, of: Move PCI I/O space management to PCI core codeTomasz Nowicki
No functional changes in this patch. PCI I/O space mapping code does not depend on OF; therefore it can be moved to PCI core code. This way we will be able to use it, e.g., in ACPI PCI code. Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Tomasz Nowicki <tn@semihalf.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Arnd Bergmann <arnd@arndb.de> CC: Liviu Dudau <Liviu.Dudau@arm.com>
2016-04-25Merge branches 'pci/enumeration', 'pci/hotplug', 'pci/misc', 'pci/ntb', ↵Bjorn Helgaas
'pci/thunderbolt' and 'pci/virtualization' into next * pci/enumeration: x86/PCI: Refine PCI support check in pcibios_init() * pci/hotplug: PCI: acpiphp_ibm: Avoid uninitialized variable reference * pci/misc: PCI: Fix spelling errors * pci/ntb: PCI: Add DMA alias quirk for mic_x200_dma PCI: Add support for multiple DMA aliases PCI: Move informational printk to pci_add_dma_alias() PCI: Add pci_add_dma_alias() to abstract implementation * pci/thunderbolt: thunderbolt: Support 1st gen Light Ridge controller thunderbolt: Fix typos and magic number PCI: Add Intel Thunderbolt device IDs * pci/virtualization: PCI: Work around Intel Sunrise Point PCH incorrect ACS capability PCI: Reverse standard ACS vs device-specific ACS enabling PCI: Mark Intel i40e NIC INTx masking as broken
2016-04-19PCI: Reverse standard ACS vs device-specific ACS enablingAlex Williamson
The original thought was that if a device implemented ACS, then surely we want to use that... well, it turns out that devices can make an ACS capability so broken that we still need to fall back to quirks. Reverse the order of ACS enabling to give quirks first shot at it. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-04-11PCI: Add support for multiple DMA aliasesJacek Lawrynowicz
Solve IOMMU support issues with PCIe non-transparent bridges that use Requester ID look-up tables (RID-LUT), e.g., the PEX8733. The NTB connects devices in two independent PCI domains. Devices separated by the NTB are not able to discover each other. A PCI packet being forwared from one domain to another has to have its RID modified so it appears on correct bus and completions are forwarded back to the original domain through the NTB. The RID is translated using a preprogrammed table (LUT) and the PCI packet propagates upstream away from the NTB. If the destination system has IOMMU enabled, the packet will be discarded because the new RID is unknown to the IOMMU. Adding a DMA alias for the new RID allows IOMMU to properly recognize the packet. Each device behind the NTB has a unique RID assigned in the R