kernel.git/drivers/pci/probe.c, branch linux-4.10.y

PCI: Enumerate switches below PCI-to-PCIe bridges

2017-01-11T15:11:53Z

A PCI-to-PCIe bridge (a "reverse bridge") has a PCI or PCI-X primary interface and a PCI Express secondary interface. The PCIe interface is a Downstream Port that originates a Link. See the "PCI Express to PCI/PCI-X Bridge Specification", rev 1.0, sections 1.2 and A.6. The bug report below involves a PCI-to-PCIe bridge and a PCIe switch below the bridge: 00:1e.0 Intel 82801 PCI Bridge to [bus 01-0a] 01:00.0 Pericom PI7C9X111SL PCIe-to-PCI Reversible Bridge to [bus 02-0a] 02:00.0 Pericom Device 8608 [PCIe Upstream Port] to [bus 03-0a] 03:01.0 Pericom Device 8608 [PCIe Downstream Port] to [bus 0a] 01:00.0 is configured as a PCI-to-PCIe bridge (despite the name printed by lspci). As we traverse a PCIe hierarchy, device connections alternate between PCIe Links and internal Switch logic. Previously we did not recognize that 01:00.0 had a secondary link, so we thought the 02:00.0 Upstream Port *did* have a secondary link. In fact, it's the other way around: 01:00.0 has a secondary link, and 02:00.0 has internal Switch logic on its secondary side. When we thought 02:00.0 had a secondary link, the pci_scan_slot() -> only_one_child() path assumed 02:00.0 could have only one child, so 03:00.0 was the only possible downstream device. But 03:00.0 doesn't exist, so we didn't look for any other devices on bus 03. Booting with "pci=pcie_scan_all" is a workaround, but we don't want users to have to do that. Recognize that PCI-to-PCIe bridges originate links on their secondary interfaces. Link: https://bugzilla.kernel.org/show_bug.cgi?id=189361 Fixes: d0751b98dfa3 ("PCI: Add dev->has_secondary_link to track downstream PCIe links") Tested-by: Blake Moore Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v4.2+

Merge tag 'pci-v4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2016-12-15T20:46:48Z

Pull PCI updates from Bjorn Helgaas: "PCI changes: - add support for PCI on ARM64 boxes with ACPI. We already had this for theoretical spec-compliant hardware; now we're adding quirks for the actual hardware (Cavium, HiSilicon, Qualcomm, X-Gene) - add runtime PM support for hotplug ports - enable runtime suspend for Intel UHCI that uses platform-specific wakeup signaling - add yet another host bridge registration interface. We hope this is extensible enough to subsume the others - expose device revision in sysfs for DRM - to avoid device conflicts, make sure any VF BAR updates are done before enabling the VF - avoid unnecessary link retrains for ASPM - allow INTx masking on Mellanox devices that support it - allow access to non-standard VPD for Chelsio devices - update Broadcom iProc support for PAXB v2, PAXC v2, inbound DMA, etc - update Rockchip support for max-link-speed - add NVIDIA Tegra210 support - add Layerscape LS1046a support - update R-Car compatibility strings - add Qualcomm MSM8996 support - remove some uninformative bootup messages" * tag 'pci-v4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (115 commits) PCI: Enable access to non-standard VPD for Chelsio devices (cxgb3) PCI: Expand "VPD access disabled" quirk message PCI: pciehp: Remove loading message PCI: hotplug: Remove hotplug core message PCI: Remove service driver load/unload messages PCI/AER: Log AER IRQ when claiming Root Port PCI/AER: Log errors with PCI device, not PCIe service device PCI/AER: Remove unused version macros PCI/PME: Log PME IRQ when claiming Root Port PCI/PME: Drop unused support for PMEs from Root Complex Event Collectors PCI: Move config space size macros to pci_regs.h x86/platform/intel-mid: Constify mid_pci_platform_pm PCI/ASPM: Don't retrain link if ASPM not possible PCI: iproc: Skip check for legacy IRQ on PAXC buses PCI: pciehp: Leave power indicator on when enabling already-enabled slot PCI: pciehp: Prioritize data-link event over presence detect PCI: rcar: Add gen3 fallback compatibility string for pcie-rcar PCI: rcar: Use gen2 fallback compatibility last PCI: rcar-gen2: Use gen2 fallback compatibility last PCI: rockchip: Move the deassert of pm/aclk/pclk after phy_init() ..

Merge branch 'pci/host-tegra' into next

2016-12-12T17:25:12Z

* pci/host-tegra: arm64: tegra: Enable PCIe on Jetson TX1 arm64: tegra: Add PCIe host bridge on Tegra210 PCI: tegra: Enable the driver on 64-bit ARM PCI: tegra: Add Tegra210 support PCI: tegra: Implement PCA enable workaround dt-bindings: pci: tegra: Add Tegra210 support PCI: tegra: Use new pci_register_host_bridge() interface PCI: Export host bridge registration interface PCI: Allow driver-specific data in host bridge PCI: Add pci_register_host_bridge() interface

PCI: Export host bridge registration interface

2016-12-07T18:05:58Z

Allow PCI host bridge drivers to use the new host bridge interfaces to register their host bridge. Signed-off-by: Thierry Reding Signed-off-by: Bjorn Helgaas

PCI: Allow driver-specific data in host bridge

2016-12-07T18:05:48Z

Provide a way to allocate driver-specific data along with a PCI host bridge structure. The bridge's ->private field points to this data. Signed-off-by: Thierry Reding Signed-off-by: Bjorn Helgaas

PCI: Add pci_register_host_bridge() interface

2016-12-07T17:05:42Z

Make the existing pci_host_bridge structure a proper device that is usable by PCI host drivers in a more standard way. In addition to the existing pci_scan_bus(), pci_scan_root_bus(), pci_scan_root_bus_msi(), and pci_create_root_bus() interfaces, this unfortunately means having to add yet another interface doing basically the same thing, and add some extra code in the initial step. However, this time it's more likely to be extensible enough that we won't have to do another one again in the future, and we should be able to reduce code much more as a result. The main idea is to pull the allocation of 'struct pci_host_bridge' out of the registration, and let individual host drivers and architecture code fill the members before calling the registration function. There are a number of things we can do based on this: * Use a single memory allocation for the driver-specific structure and the generic PCI host bridge * consolidate the contents of driver-specific structures by moving them into pci_host_bridge * Add a consistent interface for removing a PCI host bridge again when unloading a host driver module * Replace the architecture specific __weak pcibios_*() functions with callbacks in a pci_host_bridge device * Move common boilerplate code from host drivers into the generic function, based on contents of the structure * Extend pci_host_bridge with additional members when needed without having to add arguments to pci_scan_*(). * Move members of struct pci_bus into pci_host_bridge to avoid having lots of identical copies. Signed-off-by: Arnd Bergmann Signed-off-by: Thierry Reding Signed-off-by: Bjorn Helgaas

Merge branches 'arm/mediatek', 'arm/smmu', 'x86/amd', 's390', 'core' and 'arm/exynos' into next

2016-12-06T16:32:16Z

PCI: Decouple IORESOURCE_ROM_ENABLE and PCI_ROM_ADDRESS_ENABLE

2016-11-30T00:05:09Z

Remove the assumption that IORESOURCE_ROM_ENABLE == PCI_ROM_ADDRESS_ENABLE. PCI_ROM_ADDRESS_ENABLE is the ROM enable bit defined by the PCI spec, so if we're reading or writing a BAR register value, that's what we should use. IORESOURCE_ROM_ENABLE is a corresponding bit in struct resource flags. Signed-off-by: Bjorn Helgaas Reviewed-by: Gavin Shan

ACPI: Implement acpi_dma_configure

2016-11-29T15:57:44Z

On DT based systems, the of_dma_configure() API implements DMA configuration for a given device. On ACPI systems an API equivalent to of_dma_configure() is missing which implies that it is currently not possible to set-up DMA operations for devices through the ACPI generic kernel layer. This patch fills the gap by introducing acpi_dma_configure/deconfigure() calls that for now are just wrappers around arch_setup_dma_ops() and arch_teardown_dma_ops() and also updates ACPI and PCI core code to use the newly introduced acpi_dma_configure/acpi_dma_deconfigure functions. Since acpi_dma_configure() is used to configure DMA operations, the function initializes the dma/coherent_dma masks to sane default values if the current masks are uninitialized (also to keep the default values consistent with DT systems) to make sure the device has a complete default DMA set-up. The DMA range size passed to arch_setup_dma_ops() is sized according to the device coherent_dma_mask (starting at address 0x0), mirroring the DT probing path behaviour when a dma-ranges property is not provided for the device being probed; this changes the current arch_setup_dma_ops() call parameters in the ACPI probing case, but since arch_setup_dma_ops() is a NOP on all architectures but ARM/ARM64 this patch does not change the current kernel behaviour on them. Signed-off-by: Lorenzo Pieralisi Acked-by: Bjorn Helgaas [pci] Acked-by: Rafael J. Wysocki Reviewed-by: Tomasz Nowicki Tested-by: Hanjun Guo Tested-by: Tomasz Nowicki Cc: Bjorn Helgaas Cc: Robin Murphy Cc: Tomasz Nowicki Cc: Joerg Roedel Cc: "Rafael J. Wysocki" Signed-off-by: Will Deacon

PCI: Set Read Completion Boundary to 128 iff Root Port supports it (_HPX)

2016-11-23T22:23:55Z

Per PCIe spec r3.0, sec 2.3.1.1, the Read Completion Boundary (RCB) determines the naturally aligned address boundaries on which a Read Request may be serviced with multiple Completions: - For a Root Complex, RCB is 64 bytes or 128 bytes This value is reported in the Link Control Register Note: Bridges and Endpoints may implement a corresponding command bit which may be set by system software to indicate the RCB value for the Root Complex, allowing the Bridge/Endpoint to optimize its behavior when the Root Complex’s RCB is 128 bytes. - For all other system elements, RCB is 128 bytes Per sec 7.8.7, if a Root Port only supports a 64-byte RCB, the RCB of all downstream devices must be clear, indicating an RCB of 64 bytes. If the Root Port supports a 128-byte RCB, we may optionally set the RCB of downstream devices so they know they can generate larger Completions. Some BIOSes supply an _HPX that tells us to set RCB, even though the Root Port doesn't have RCB set, which may lead to Malformed TLP errors if the Endpoint generates completions larger than the Root Port can handle. The IBM x3850 X6 with BIOS version -[A8E120CUS-1.30]- 08/22/2016 supplies such an _HPX and a Mellanox MT27500 ConnectX-3 device fails to initialize: mlx4_core 0000:41:00.0: command 0xfff timed out (go bit not cleared) mlx4_core 0000:41:00.0: device is going to be reset mlx4_core 0000:41:00.0: Failed to obtain HW semaphore, aborting mlx4_core 0000:41:00.0: Fail to reset HCA ------------[ cut here ]------------ kernel BUG at drivers/net/ethernet/mellanox/mlx4/catas.c:193! After 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration") and 7a1562d4f2d0 ("PCI: Apply _HPX Link Control settings to all devices with a link"), we apply _HPX settings to *all* devices, not just those hot-added after boot. Before 7a1562d4f2d0, we didn't touch the Mellanox RCB, and the device worked. After 7a1562d4f2d0, we set its RCB to 128, and it failed. Set the RCB to 128 iff the Root Port supports a 128-byte RCB. Otherwise, set RCB to 64 bytes. This effectively ignores what _HPX tells us about RCB. Note that this change only affects _HPX handling. If we have no _HPX, this does nothing with RCB. [bhelgaas: changelog, clear RCB if not set for Root Port] Fixes: 6cd33649fa83 ("PCI: Add pci_configure_device() during enumeration") Fixes: 7a1562d4f2d0 ("PCI: Apply _HPX Link Control settings to all devices with a link") Link: https://bugzilla.kernel.org/show_bug.cgi?id=187781 Tested-by: Frank Danapfel Signed-off-by: Johannes Thumshirn Signed-off-by: Bjorn Helgaas Acked-by: Myron Stowe CC: stable@vger.kernel.org # v3.18+