- 15 Aug, 2018 12 commits
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Bjorn Helgaas authored
- Add "pci=disable_acs_redir=" parameter to disable ACS redirection for peer-to-peer DMA support (we don't have the peer-to-peer support yet; this is just one piece) (Logan Gunthorpe) * pci/peer-to-peer: PCI: Add ACS Redirect disable quirk for Intel Sunrise Point PCI: Add device-specific ACS Redirect disable infrastructure PCI: Convert device-specific ACS quirks from NULL termination to ARRAY_SIZE PCI: Add "pci=disable_acs_redir=" parameter for peer-to-peer support PCI: Allow specifying devices using a base bus and path of devfns PCI: Make specifying PCI devices in kernel parameters reusable PCI: Hide ACS quirk declarations inside PCI core -
Bjorn Helgaas authored
- Document ACPI description of PCI host bridges (Bjorn Helgaas) * pci/notes: PCI: Document ACPI description of PCI host bridges
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Bjorn Helgaas authored
- Set IRQCHIP_ONESHOT_SAFE for PCI MSI irqchips (Heiner Kallweit) * pci/msi: PCI/MSI: Set IRQCHIP_ONESHOT_SAFE for PCI-MSI irqchips
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Bjorn Helgaas authored
- Mark fall-through switch cases before enabling -Wimplicit-fallthrough (Gustavo A. R. Silva) - Move DMA-debug PCI init from arch code to PCI core (Christoph Hellwig) - Fix pci_request_irq() usage of IRQF_ONESHOT when no handler is supplied (Heiner Kallweit) - Unify PCI and DMA direction #defines (Shunyong Yang) - Add PCI_DEVICE_DATA() macro (Andy Shevchenko) - Check for VPD completion before checking for timeout (Bert Kenward) - Limit Netronome NFP5000 config space size to work around erratum (Jakub Kicinski) * pci/misc: PCI: Limit config space size for Netronome NFP5000 PCI/VPD: Check for VPD access completion before checking for timeout PCI: Add PCI_DEVICE_DATA() macro to fully describe device ID entry PCI: Unify PCI and normal DMA direction definitions PCI: Use IRQF_ONESHOT if pci_request_irq() called with no handler PCI: Call dma_debug_add_bus() for pci_bus_type from PCI core PCI: Mark fall-through switch cases before enabling -Wimplicit-fallthrough # Conflicts: # drivers/pci/hotplug/pciehp_ctrl.c -
Bjorn Helgaas authored
- Simplify SHPC existence/permission checks (Bjorn Helgaas) - Remove hotplug sample skeleton driver (Lukas Wunner) - Convert pciehp to threaded IRQ handling (Lukas Wunner) - Improve pciehp tolerance of missed events and initially unstable links (Lukas Wunner) - Clear spurious pciehp events on resume (Lukas Wunner) - Add pciehp runtime PM support, including for Thunderbolt controllers (Lukas Wunner) - Support interrupts from pciehp bridges in D3hot (Lukas Wunner) * pci/hotplug: PCI: pciehp: Deduplicate presence check on probe & resume PCI: pciehp: Avoid implicit fallthroughs in switch statements PCI: Whitelist Thunderbolt ports for runtime D3 PCI: Whitelist native hotplug ports for runtime D3 PCI: sysfs: Resume to D0 on function reset PCI: pciehp: Resume parent to D0 on config space access PCI: pciehp: Resume to D0 on enable/disable PCI: pciehp: Support interrupts sent from D3hot PCI: pciehp: Obey compulsory command delay after resume PCI: pciehp: Clear spurious events earlier on resume PCI: portdrv: Deduplicate PM callback iterator PCI: pciehp: Avoid slot access during reset PCI: pciehp: Always enable occupied slot on probe PCI: pciehp: Become resilient to missed events PCI: pciehp: Tolerate initially unstable link PCI: pciehp: Declare pciehp_enable/disable_slot() static PCI: pciehp: Drop enable/disable lock PCI: pciehp: Enable/disable exclusively from IRQ thread PCI: pciehp: Track enable/disable status PCI: pciehp: Publish to user space last on probe PCI: hotplug: Demidlayer registration with the core PCI: pciehp: Drop slot workqueue PCI: pciehp: Handle events synchronously PCI: pciehp: Stop blinking on slot enable failure PCI: pciehp: Convert to threaded polling PCI: pciehp: Convert to threaded IRQ PCI: pciehp: Document struct slot and struct controller PCI: pciehp: Declare pciehp_unconfigure_device() void PCI: pciehp: Drop unnecessary NULL pointer check PCI: pciehp: Fix unprotected list iteration in IRQ handler PCI: pciehp: Fix use-after-free on unplug PCI: hotplug: Don't leak pci_slot on registration failure PCI: hotplug: Delete skeleton driver PCI: shpchp: Separate existence of SHPC and permission to use it -
Bjorn Helgaas authored
- Work around IDT switch ACS Source Validation erratum (James Puthukattukaran) - Emit diagnostics for all cases of PCIe Link downtraining (Links operating slower than they're capable of) (Alexandru Gagniuc) - Skip VFs when configuring Max Payload Size (Myron Stowe) - Reduce Root Port Max Payload Size if necessary when hot-adding a device below it (Myron Stowe) * pci/enumeration: PCI: Match Root Port's MPS to endpoint's MPSS as necessary PCI: Skip MPS logic for Virtual Functions (VFs) PCI: Check for PCIe Link downtraining PCI: Workaround IDT switch ACS Source Validation erratum -
Bjorn Helgaas authored
- Defer DPC event handling to work queue (Keith Busch) - Use threaded IRQ for DPC bottom half (Keith Busch) - Print AER status while handling DPC events (Keith Busch) * pci/dpc: PCI/DPC: Remove indirection waiting for inactive link PCI/DPC: Use threaded IRQ for bottom half handling PCI/DPC: Print AER status in DPC event handling PCI/DPC: Remove rp_pio_status from dpc struct PCI/DPC: Defer event handling to work queue PCI/DPC: Leave interrupts enabled while handling event
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Bjorn Helgaas authored
- Use sysfs_match_string() to simplify ASPM sysfs parsing (Andy Shevchenko) - Remove unnecessary includes of <linux/pci-aspm.h> (Bjorn Helgaas) * pci/aspm: PCI: Remove unnecessary include of <linux/pci-aspm.h> iwlwifi: Remove unnecessary include of <linux/pci-aspm.h> ath9k: Remove unnecessary include of <linux/pci-aspm.h> igb: Remove unnecessary include of <linux/pci-aspm.h> PCI/ASPM: Convert to use sysfs_match_string() helper -
Bjorn Helgaas authored
- Decode AER errors with names similar to "lspci" (Tyler Baicar) - Expose AER statistics in sysfs (Rajat Jain) - Clear AER status bits selectively based on the type of recovery (Oza Pawandeep) - Honor "pcie_ports=native" even if HEST sets FIRMWARE_FIRST (Alexandru Gagniuc) - Don't clear AER status bits if we're using the "Firmware-First" strategy where firmware owns the registers (Alexandru Gagniuc) * pci/aer: PCI/AER: Don't clear AER bits if error handling is Firmware-First PCI/AER: Remove duplicate PCI_EXP_AER_FLAGS definition PCI/portdrv: Remove pcie_portdrv_err_handler.slot_reset PCI/AER: Clear device status bits during ERR_COR handling PCI/AER: Clear device status bits during ERR_FATAL and ERR_NONFATAL PCI/AER: Remove ERR_FATAL code from ERR_NONFATAL path PCI/AER: Factor out ERR_NONFATAL status bit clearing PCI/AER: Clear only ERR_NONFATAL bits during non-fatal recovery PCI/AER: Clear only ERR_FATAL status bits during fatal recovery PCI/AER: Honor "pcie_ports=native" even if HEST sets FIRMWARE_FIRST PCI/AER: Add sysfs attributes for rootport cumulative stats PCI/AER: Add sysfs attributes to provide AER stats and breakdown PCI/AER: Define aer_stats structure for AER capable devices PCI/AER: Move internal declarations to drivers/pci/pci.h PCI/AER: Adopt lspci names for AER error decoding PCI/AER: Expose internal API for obtaining AER information # Conflicts: # drivers/pci/pci.h -
Bjorn Helgaas authored
* for-linus: PCI: Fix is_added/is_busmaster race condition PCI: mobiveil: Avoid integer overflow in IB_WIN_SIZE PCI/AER: Work around use-after-free in pcie_do_fatal_recovery() PCI: v3-semi: Fix I/O space page leak PCI: mediatek: Fix I/O space page leak PCI: faraday: Fix I/O space page leak PCI: aardvark: Fix I/O space page leak PCI: designware: Fix I/O space page leak PCI: versatile: Fix I/O space page leak PCI: xgene: Fix I/O space page leak PCI: OF: Fix I/O space page leak PCI: endpoint: Fix NULL pointer dereference error when CONFIGFS is disabled PCI: hv: Disable/enable IRQs rather than BH in hv_compose_msi_msg() nfp: stop limiting VFs to 0 PCI/IOV: Reset total_VFs limit after detaching PF driver PCI: faraday: Add missing of_node_put() PCI: xilinx-nwl: Add missing of_node_put() PCI: xilinx: Add missing of_node_put() PCI: endpoint: Use after free in pci_epf_unregister_driver() PCI: controller: dwc: Do not let PCIE_DW_PLAT_HOST default to yes PCI: rcar: Clean up PHY init on failure PCI: rcar: Shut the PHY down in failpath PCI: controller: Move PCI_DOMAINS selection to arch Kconfig PCI: Initialize endpoint library before controllers PCI: shpchp: Manage SHPC unconditionally on non-ACPI systems
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Alexandru Gagniuc authored
If the platform requests Firmware-First error handling, firmware is responsible for reading and clearing AER status bits. If OSPM also clears them, we may miss errors. See ACPI v6.2, sec 18.3.2.5 and 18.4. This race is mostly of theoretical significance, as it is not easy to reasonably demonstrate it in testing. Signed-off-by:
Alexandru Gagniuc <mr.nuke.me@gmail.com> [bhelgaas: add similar guards to pci_cleanup_aer_uncorrect_error_status() and pci_aer_clear_fatal_status()] Signed-off-by:
Bjorn Helgaas <bhelgaas@google.com>
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Jakub Kicinski authored
Like the NFP4000 and NFP6000, the NFP5000 as an erratum where reading/ writing to PCI config space addresses above 0x600 can cause the NFP to generate PCIe completion timeouts. Limit the NFP5000's PF's config space size to 0x600 bytes as is already done for the NFP4000 and NFP6000. The NFP5000's VF is 0x6003 (PCI_DEVICE_ID_NETRONOME_NFP6000_VF), the same device ID as the NFP6000's VF. Thus, its config space is already limited by the existing use of quirk_nfp6000(). Signed-off-by:
Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by:
Tony Egan <tony.egan@netronome.com>
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- 14 Aug, 2018 5 commits
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Heiner Kallweit authored
If flag IRQCHIP_ONESHOT_SAFE isn't set for an irqchip and we have a threaded interrupt with no primary handler, flag IRQF_ONESHOT needs to be set for the interrupt, causing some overhead in the threaded interrupt handler. For more detailed explanation also check following comment in __setup_irq(): The interrupt was requested with handler = NULL, so we use the default primary handler for it. But it does not have the oneshot flag set. In combination with level interrupts this is deadly, because the default primary handler just wakes the thread, then the irq lines is reenabled, but the device still has the level irq asserted. Rinse and repeat.... While this works for edge type interrupts, we play it safe and reject unconditionally because we can't say for sure which type this interrupt really has. The type flags are unreliable as the underlying chip implementation can override them. Another comment in __setup_irq() gives a hint already that this overhead can be avoided for PCI-MSI: Some irq chips like MSI based interrupts are per se one shot safe. Check the chip flags, so we can avoid the unmask dance at the end of the threaded handler for those. Following this let's mark all PCI-MSI irqchips as oneshot-safe. See also discussion here: https://lkml.kernel.org/r/alpine.DEB.2.21.1808032136490.1658@nanos.tec.linutronix.deSigned-off-by:
Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by:
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Bert Kenward authored
Previously we checked the timeout before checking the VPD access completion bit. On a very heavily loaded system this can cause VPD access to timeout. Check the completion bit before checking the timeout. Signed-off-by:
Bert Kenward <bkenward@solarflare.com> Signed-off-by:
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Andy Shevchenko authored
There are a lot of examples in the kernel where PCI_VDEVICE() is used and still looks not so convenient due to additional driver_data field attached. Introduce PCI_DEVICE_DATA() macro to fully describe device ID entry in shortest possible form. For example, before: { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MRFLD), (kernel_ulong_t) &dwc3_pci_mrfld_properties, }, after: { PCI_DEVICE_DATA(INTEL, MRFLD, &dwc3_pci_mrfld_properties) }, Drivers can be converted later on in independent way. While here, remove the unused macro with the same name from Ralink wireless driver. Signed-off-by:Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
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Myron Stowe authored
In commit 27d868b5 ("PCI: Set MPS to match upstream bridge"), we made sure every device's MPS setting matches its upstream bridge, making it more likely that a hot-added device will work in a system with an optimized MPS configuration. Recently I've started encountering systems where the endpoint device's MPSS capability is less than its Root Port's current MPS value, thus the endpoint is not capable of matching its upstream bridge's MPS setting (see: bugzilla via "Link:" below). This leaves the system vulnerable - the upstream Root Port could respond with larger TLPs than the device can handle, and the device will consider them to be 'Malformed'. One could use the "pci=pcie_bus_safe" kernel parameter to work around the issue, but that forces a user to supply a kernel parameter to get the system to function reliably and may end up limiting MPS settings of other unrelated, sub-topologies which could benefit from maintaining their larger values. Augment Keith's approach to include tuning down a Root Port's MPS setting when its hot-added endpoint device is not capable of matching it. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200527Signed-off-by:
Myron Stowe <myron.stowe@redhat.com> Signed-off-by:
Jon Mason <jdmason@kudzu.us> Cc: Keith Busch <keith.busch@intel.com> Cc: Sinan Kaya <okaya@kernel.org> Cc: Dongdong Liu <liudongdong3@huawei.com>
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Myron Stowe authored
PCIe r4.0, sec 9.3.5.4, "Device Control Register", shows both Max_Payload_Size (MPS) and Max_Read_request_Size (MRRS) to be 'RsvdP' for VFs. Just prior to the table it states: "PF and VF functionality is defined in Section 7.5.3.4 except where noted in Table 9-16. For VF fields marked 'RsvdP', the PF setting applies to the VF." All of which implies that with respect to Max_Payload_Size Supported (MPSS), MPS, and MRRS values, we should not be paying any attention to the VF's fields, but rather only to the PF's. Only looking at the PF's fields also logically makes sense as it's the sole physical interface to the PCIe bus. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200527 Fixes: 27d868b5 ("PCI: Set MPS to match upstream bridge") Signed-off-by:
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- 10 Aug, 2018 1 commit
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Alexandru Gagniuc authored
When both ends of a PCIe Link are capable of a higher bandwidth than is currently in use, the Link is said to be "downtrained". A downtrained Link may indicate hardware or configuration problems in the system, but it's hard to identify such Links from userspace. Refactor pcie_print_link_status() so it continues to always print PCIe bandwidth information, as several NIC drivers desire. Add a new internal __pcie_print_link_status() to emit a message only when a device's bandwidth is constrained by the fabric and call it from the PCI core for all devices, which identifies all downtrained Links. It also emits messages for a few cases that are technically not downtrained, such as a x4 device in an open-ended x1 slot. Signed-off-by:
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- 09 Aug, 2018 7 commits
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Logan Gunthorpe authored
Intel Sunrise Point PCH hardware has an implementation of the ACS bits that does not comply with the PCIe standard. Add a device-specific quirk, pci_quirk_disable_intel_spt_pch_acs_redir() to disable ACS Redirection on this system. Signed-off-by:
Logan Gunthorpe <logang@deltatee.com> [bhelgaas: changelog, split to separate patch] Signed-off-by:
Alex Williamson <alex.williamson@redhat.com>
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Logan Gunthorpe authored
Intel Sunrise Point (SPT) PCH hardware has an implementation of the ACS bits that does not comply with the PCIe standard. To deal with this we need device-specific quirks to disable ACS redirection. Add a new pci_dev_specific_disable_acs_redir() quirk and a new .disable_acs_redir() function pointer for use by non-compliant devices. No functional change intended. Signed-off-by:
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Logan Gunthorpe authored
Convert the search for device-specific ACS enable quirks from searching a NULL-terminated array to iterating through the array, which is always fixed-size anyway. No functional change intended. Signed-off-by:
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Logan Gunthorpe authored
To support peer-to-peer traffic on a segment of the PCI hierarchy, we must disable the ACS redirect bits for select PCI bridges. The bridges must be selected before the devices are discovered by the kernel and the IOMMU groups created. Therefore, add a kernel command line parameter to specify devices which must have their ACS bits disabled. The new parameter takes a list of devices separated by a semicolon. Each device specified will have its ACS redirect bits disabled. This is similar to the existing 'resource_alignment' parameter. The ACS Request P2P Request Redirect, P2P Completion Redirect and P2P Egress Control bits are disabled, which is sufficient to always allow passing P2P traffic uninterrupted. The bits are set after the kernel (optionally) enables the ACS bits itself. It is also done regardless of whether the kernel or platform firmware sets the bits. If the user tries to disable the ACS redirect for a device without the ACS capability, print a warning to dmesg. Signed-off-by:
Stephen Bates <sbates@raithlin.com> Reviewed-by:
Christian König <christian.koenig@amd.com>
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Logan Gunthorpe authored
When specifying PCI devices on the kernel command line using a bus/device/function address, bus numbers can change when adding or replacing a device, changing motherboard firmware, or applying kernel parameters like "pci=assign-buses". When bus numbers change, it's likely the command line tweak will be applied to the wrong device. Therefore, it is useful to be able to specify devices with a base bus number and the path of devfns needed to get to it, similar to the "device scope" structure in the Intel VT-d spec, Section 8.3.1. Thus, we add an option to specify devices in the following format: [<domain>:]<bus>:<device>.<func>[/<device>.<func>]* The path can be any segment within the PCI hierarchy of any length and determined through the use of 'lspci -t'. When specified this way, it is less likely that a renumbered bus will result in a valid device specification and the tweak won't be applied to the wrong device. Signed-off-by:
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Logan Gunthorpe authored
Separate out the code to match a PCI device with a string (typically originating from a kernel parameter) from the pci_specified_resource_alignment() function into its own helper function. While we are at it, this change fixes the kernel style of the function (fixing a number of long lines and extra parentheses). Additionally, make the analogous change to the kernel parameter documentation: Separate the description of how to specify a PCI device into its own section at the head of the "pci=" parameter. This patch should have no functional alterations. Signed-off-by:
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Bjorn Helgaas authored
Move declarations for these functions: pci_dev_specific_acs_enabled() pci_dev_specific_enable_acs() from include/linux/pci.h to drivers/pci/pci.h because nothing outside the PCI core needs to use them. Signed-off-by:
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- 06 Aug, 2018 5 commits
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Bjorn Helgaas authored
Several PCI core files include pci-aspm.h even though they don't need anything provided by that file. Remove the unnecessary includes of it. Signed-off-by:
Sinan Kaya <okaya@kernel.org>
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Bjorn Helgaas authored
This part of the iwlwifi driver doesn't need anything provided by pci-aspm.h, so remove the unnecessary include of it. Signed-off-by:
Luca Coelho <luciano.coelho@intel.com>
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Bjorn Helgaas authored
The ath9k driver doesn't need anything provided by pci-aspm.h, so remove the unnecessary include of it. Signed-off-by:
Kalle Valo <kvalo@codeaurora.org>
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Bjorn Helgaas authored
The igb driver doesn't need anything provided by pci-aspm.h, so remove the unnecessary include of it. Signed-off-by:
Alexander Duyck <alexander.h.duyck@intel.com> Acked-by:
Jeff Kirsher <jeffrey.t.kirsher@intel.com>
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Andy Shevchenko authored
The sysfs_match_string() helper returns index of the matching string in an array. Use it in pcie_aspm_set_policy() to simplify the code. Signed-off-by:
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- 31 Jul, 2018 10 commits
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Shunyong Yang authored
Current DMA direction definitions in pci-dma-compat.h and dma-direction.h are mirrored in value. Unify them to enhance readability and avoid possible inconsistency. Signed-off-by:
Shunyong Yang <shunyong.yang@hxt-semitech.com> Signed-off-by:
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Bjorn Helgaas authored
PCI_EXP_AER_FLAGS was defined twice (with identical definitions), once under #ifdef CONFIG_ACPI_APEI, and again at the top level. This looks like my merge error from these commits: fd3362cb ("PCI/AER: Squash aerdrv_core.c into aerdrv.c") 41cbc9eb ("PCI/AER: Squash ecrc.c into aerdrv.c") Remove the duplicate PCI_EXP_AER_FLAGS definition. Fixes: 41cbc9eb ("PCI/AER: Squash ecrc.c into aerdrv.c") Signed-off-by:
Oza Pawandeep <poza@codeaurora.org>
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Lukas Wunner authored
On driver probe and on resume from system sleep, pciehp checks the Presence Detect State bit in the Slot Status register to bring up an occupied slot or bring down an unoccupied slot. Both code paths are identical, so deduplicate them per Mika's request. On probe, an additional check is performed to disable power of an unoccupied slot. This can e.g. happen if power was enabled by BIOS. It cannot happen once pciehp has taken control, hence is not necessary on resume: The Slot Control register is set to the same value that it had on suspend by pci_restore_state(), so if the slot was occupied, power is enabled and if it wasn't, power is disabled. Should occupancy have changed during the system sleep transition, power is adjusted by bringing up or down the slot per the paragraph above. To allow for deduplication of the presence check, move the power check to pcie_init(). This seems safer anyway, because right now it is performed while interrupts are already enabled, and although I can't think of a scenario where pciehp_power_off_slot() and the IRQ thread collide, it does feel brittle. However this means that pcie_init() may now write to the Slot Control register before the IRQ is requested. If both the CCIE and HPIE bits happen to be set, pcie_wait_cmd() will wait for an interrupt (instead of polling the Command Completed bit) and eventually emit a timeout message. Additionally, if a level-triggered INTx interrupt is used, the user may see a spurious interrupt splat. Avoid by disabling interrupts before disabling power. (Normally the HPIE and CCIE bits should be clear on probe, but conceivably they may already have been set e.g. by BIOS.) Signed-off-by:
Lukas Wunner <lukas@wunner.de> Signed-off-by:
Mika Westerberg <mika.westerberg@linux.intel.com>
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Lukas Wunner authored
Per Mika's request, add an explicit break to the last case of switch statements everywhere in pciehp to be more defensive towards future amendments. Per Gustavo's request, mark all non-empty implicit fallthroughs with a comment to silence warnings triggered by -Wimplicit-fallthrough=2. Signed-off-by:
Gustavo A. R. Silva <gustavo@embeddedor.com>
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Hari Vyas authored
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=200283Signed-off-by:
Hari Vyas <hari.vyas@broadcom.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Lukas Wunner authored
Thunderbolt controllers can be runtime suspended to D3cold to save ~1.5W. This requires that runtime D3 is allowed on its PCIe ports, so whitelist them. The 2015 BIOS cutoff that we've instituted for runtime D3 on PCIe ports is unnecessary on Thunderbolt because we know that even the oldest controller, Light Ridge (2010), is able to suspend its ports to D3 just fine -- specifically including its hotplug ports. And the power saving should be afforded to machines even if their BIOS predates 2015. Signed-off-by:
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Lukas Wunner authored
Previously we blacklisted PCIe hotplug ports for runtime D3 because: (a) Ports handled by the firmware must not be transitioned to D3 by the OS behind the firmware's back: https://bugzilla.kernel.org/show_bug.cgi?id=53811 (b) Ports handled natively by the OS lacked runtime D3 support in the pciehp driver. We've just rectified the latter, so allow users to manually enable and test it by passing pcie_port_pm=force on the command line. Vendors are thus put in a position to validate hotplug ports for runtime D3 and perhaps we can someday enable it by default, but with a BIOS cutoff date. Ashok Raj tested runtime D3 on hotplug ports of a SkyLake Xeon-SP in 2017 and encountered Hardware Error NMIs, so this feature clearly cannot be enabled for everyone yet: https://lkml.kernel.org/r/20170503180426.GA4058@otc-nc-03 While at it, remove an erroneous code comment I added with 97a90aee ("PCI: Consolidate conditions to allow runtime PM on PCIe ports") which claims that parents of a hotplug port must stay awake lest interrupts cannot be delivered. That has turned out to be wrong at least for Thunderbolt hotplug ports. Signed-off-by: -
Lukas Wunner authored
When performing a function reset via sysfs, the device's config space is accessed in places such as pcie_flr() and its MMIO space is accessed e.g. in reset_ivb_igd(), so ensure accessibility by resuming the device to D0. Signed-off-by:
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Lukas Wunner authored
Ensure accessibility of a hotplug port's config space when accessed via sysfs by resuming its parent to D0. Signed-off-by:
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Lukas Wunner authored
pciehp's IRQ thread ensures accessibility of the port by runtime resuming its parent to D0. However when the slot is enabled/disabled, the port itself needs to be in D0 because its secondary bus is accessed in: pciehp_check_link_status(), pciehp_configure_device() (both called from board_added()) and pciehp_unconfigure_device() (called from remove_board()). Thus, acquire a runtime PM ref on enable/disablement of the slot. Yinghai Lu additionally discovered that some SkyLake servers feature a Power Controller for their PCIe hotplug ports (PCIe r3.1, sec 6.7.1.8) which requires the port to be in D0 when invoking pciehp_power_on_slot() (likewise called from board_added()). If slot power is turned on while in D3hot, link training later fails: https://lkml.kernel.org/r/20170205073454.GA253@wunner.de The spec is silent about such a requirement, but it seems prudent to assume that any hotplug port with a Power Controller may need this. The present commit holds a runtime PM ref whenever slot power is turned on and off, but it doesn't keep the port in D0 as long as slot power is on. If vendors determine that's necessary, they need to amend pciehp to acquire a runtime PM ref in pciehp_power_on_slot() and release one in pciehp_power_off_slot(). Signed-off-by:
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