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path: root/drivers/pci/pcie/dpc.c
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2023-10-24PCI/DPC: Use defines with DPC reason fieldsIlpo Järvinen1-10/+17
Add new defines for DPC reason fields and use them instead of literals. Link: https://lore.kernel.org/r/20231018113254.17616-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> [bhelgaas: shorten comments] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2023-10-24PCI/DPC: Use defined fields with DPC_CTL registerIlpo Järvinen1-3/+7
Instead of using a literal to clear bits, add PCI_EXP_DPC_CTL_EN_MASK and use the usual pattern to modify a bitfield. While at it, rearrange RMW code more logically together. Link: https://lore.kernel.org/r/20231018113254.17616-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2023-10-24PCI/DPC: Use FIELD_GET()Bjorn Helgaas1-2/+3
Use FIELD_GET() to remove dependencies on the field position, i.e., the shift value. No functional change intended. Link: https://lore.kernel.org/r/20231018113254.17616-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2023-04-12PCI/PM: Drop pci_bridge_wait_for_secondary_bus() timeout parameterMika Westerberg1-2/+1
All callers of pci_bridge_wait_for_secondary_bus() supply a timeout of PCIE_RESET_READY_POLL_MS, so drop the parameter. Move the definition of PCIE_RESET_READY_POLL_MS into pci.c, the only user. [bhelgaas: extracted from https://lore.kernel.org/r/20230404052714.51315-3-mika.westerberg@linux.intel.com] Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2023-02-09PCI/DPC: Await readiness of secondary bus after resetLukas Wunner1-2/+2
pci_bridge_wait_for_secondary_bus() is called after a Secondary Bus Reset, but not after a DPC-induced Hot Reset. As a result, the delays prescribed by PCIe r6.0 sec 6.6.1 are not observed and devices on the secondary bus may be accessed before they're ready. One affected device is Intel's Ponte Vecchio HPC GPU. It comprises a PCIe switch whose upstream port is not immediately ready after reset. Because its config space is restored too early, it remains in D0uninitialized, its subordinate devices remain inaccessible and DPC recovery fails with messages such as: i915 0000:8c:00.0: can't change power state from D3cold to D0 (config space inaccessible) intel_vsec 0000:8e:00.1: can't change power state from D3cold to D0 (config space inaccessible) pcieport 0000:89:02.0: AER: device recovery failed Fix it. Link: https://lore.kernel.org/r/9f5ff00e1593d8d9a4b452398b98aa14d23fca11.1673769517.git.lukas@wunner.de Tested-by: Ravi Kishore Koppuravuri <ravi.kishore.koppuravuri@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: stable@vger.kernel.org
2022-09-28PCI/DPC: Quirk PIO log size for certain Intel Root PortsMika Westerberg1-5/+10
Some Root Ports on Intel Tiger Lake and Alder Lake systems support the RP Extensions for DPC and the RP PIO Log registers but incorrectly advertise an RP PIO Log Size of zero. This means the kernel complains that: DPC: RP PIO log size 0 is invalid and if DPC is triggered, the DPC driver will not dump the RP PIO Log registers when it should. This is caused by a BIOS bug and should be fixed the BIOS for future CPUs. Add a quirk to set the correct RP PIO Log size for the affected Root Ports. Link: https://bugzilla.kernel.org/show_bug.cgi?id=209943 Link: https://lore.kernel.org/r/20220816102042.69125-1-mika.westerberg@linux.intel.com Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
2021-11-18PCI/DPC: Use PCI_POSSIBLE_ERROR() to check config readsNaveen Naidu1-2/+2
When config pci_ops.read() can detect failed PCI transactions, the data returned to the CPU is PCI_ERROR_RESPONSE (~0 or 0xffffffff). Obviously a successful PCI config read may *also* return that data if a config register happens to contain ~0, so it doesn't definitively indicate an error unless we know the register cannot contain ~0. Use PCI_POSSIBLE_ERROR() to check the response we get when we read data from hardware. This unifies PCI error response checking and makes error checks consistent and easier to find. Compile tested only. Link: https://lore.kernel.org/r/9b0632f1f183432149f495cf12bdd5a72cc597a4.1637243717.git.naveennaidu479@gmail.com Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2021-06-17PCI: pciehp: Ignore Link Down/Up caused by DPCLukas Wunner1-5/+69
Downstream Port Containment (PCIe r5.0, sec. 6.2.10) disables the link upon an error and attempts to re-enable it when instructed by the DPC driver. A slot which is both DPC- and hotplug-capable is currently powered off by pciehp once DPC is triggered (due to the link change) and powered back up on successful recovery. That's undesirable, the slot should remain powered so the hotplugged device remains bound to its driver. DPC notifies the driver of the error and of successful recovery in pcie_do_recovery() and the driver may then restore the device to working state. Moreover, Sinan points out that turning off slot power by pciehp may foil recovery by DPC: Power off/on is a cold reset concurrently to DPC's warm reset. Sathyanarayanan reports extended delays or failure in link retraining by DPC if pciehp brings down the slot. Fix by detecting whether a Link Down event is caused by DPC and awaiting recovery if so. On successful recovery, ignore both the Link Down and the subsequent Link Up event. Afterwards, check whether the link is down to detect surprise-removal or another DPC event immediately after DPC recovery. Ensure that the corresponding DLLSC event is not ignored by synthesizing it and invoking irq_wake_thread() to trigger a re-run of pciehp_ist(). The IRQ threads of the hotplug and DPC drivers, pciehp_ist() and dpc_handler(), race against each other. If pciehp is faster than DPC, it will wait until DPC recovery completes. Recovery consists of two steps: The first step (waiting for link disablement) is recognizable by pciehp through a set DPC Trigger Status bit. The second step (waiting for link retraining) is recognizable through a newly introduced PCI_DPC_RECOVERING flag. If DPC is faster than pciehp, neither of the two flags will be set and pciehp may glean the recovery status from the new PCI_DPC_RECOVERED flag. The flag is zero if DPC didn't occur at all, hence DLLSC events are not ignored by default. pciehp waits up to 4 seconds before assuming that DPC recovery failed and bringing down the slot. This timeout is not taken from the spec (it doesn't mandate one) but based on a report from Yicong Yang that DPC may take a bit more than 3 seconds on HiSilicon's Kunpeng platform. The timeout is necessary because the DPC Trigger Status bit may never clear: On Root Ports which support RP Extensions for DPC, the DPC driver polls the DPC RP Busy bit for up to 1 second before giving up on DPC recovery. Without the timeout, pciehp would then wait indefinitely for DPC to complete. This commit draws inspiration from previous attempts to synchronize DPC with pciehp: By Sinan Kaya, August 2018: https://lore.kernel.org/linux-pci/20180818065126.77912-1-okaya@kernel.org/ By Ethan Zhao, October 2020: https://lore.kernel.org/linux-pci/20201007113158.48933-1-haifeng.zhao@intel.com/ By Kuppuswamy Sathyanarayanan, March 2021: https://lore.kernel.org/linux-pci/59cb30f5e5ac6d65427ceaadf1012b2ba8dbf66c.1615606143.git.sathyanarayanan.kuppuswamy@linux.intel.com/ Link: https://lore.kernel.org/r/0be565d97438fe2a6d57354b3aa4e8626952a00b.1619857124.git.lukas@wunner.de Reported-by: Sinan Kaya <okaya@kernel.org> Reported-by: Ethan Zhao <haifeng.zhao@intel.com> Reported-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Tested-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Tested-by: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Keith Busch <kbusch@kernel.org>
2020-09-18PCI: pciehp: Reduce noisiness on hot removalLukas Wunner1-2/+5
When a PCIe card is hot-removed, the Presence Detect State and Data Link Layer Link Active bits often do not clear simultaneously. I've seen delays of up to 244 msec between the two events with Thunderbolt. After pciehp has brought down the slot in response to the first event, the other bit may still be set. It's not discernible whether it's set because a new card is already in the slot or if it will soon clear. So pciehp tries to bring up the slot and in the latter case fails with a bunch of messages, some of them at KERN_ERR severity. If the slot is no longer occupied, the messages are false positives and annoy users. Stuart Hayes reports the following splat on hot removal: KERN_INFO pcieport 0000:3c:06.0: pciehp: Slot(180): Link Up KERN_INFO pcieport 0000:3c:06.0: pciehp: Timeout waiting for Presence Detect KERN_ERR pcieport 0000:3c:06.0: pciehp: link training error: status 0x0001 KERN_ERR pcieport 0000:3c:06.0: pciehp: Failed to check link status Dongdong Liu complains about a similar splat: KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): Link Down KERN_INFO iommu: Removing device 0000:87:00.0 from group 12 KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): Card present KERN_INFO pcieport 0000:80:10.0: Data Link Layer Link Active not set in 1000 msec KERN_ERR pciehp 0000:80:10.0:pcie004: Failed to check link status Users are particularly irritated to see a bringup attempt even though the slot was explicitly brought down via sysfs. In a perfect world, we could avoid this by setting Link Disable on slot bringdown and re-enabling it upon a Presence Detect State change. In reality however, there are broken hotplug ports which hardwire Presence Detect to zero, see 80696f991424 ("PCI: pciehp: Tolerate Presence Detect hardwired to zero"). Conversely, PCIe r1.0 hotplug ports hardwire Link Active to zero because Link Active Reporting wasn't specified before PCIe r1.1. On unplug, some ports first clear Presence then Link (see Stuart Hayes' splat) whereas others use the inverse order (see Dongdong Liu's splat). To top it off, there are hotplug ports which flap the Presence and Link bits on slot bringup, see 6c35a1ac3da6 ("PCI: pciehp: Tolerate initially unstable link"). pciehp is designed to work with all of these variants. Surplus attempts at slot bringup are a lesser evil than not being able to bring up slots at all. Although we could try to perfect the behavior for specific hotplug controllers, we'd risk breaking others or increasing code complexity. But we can certainly minimize annoyance by emitting only a single message with KERN_INFO severity if bringup is unsuccessful: * Drop the "Timeout waiting for Presence Detect" message in pcie_wait_for_presence(). The sole caller of that function, pciehp_check_link_status(), ignores the timeout and carries on. It emits error messages of its own and I don't think this particular message adds much value. * There's a single error condition in pciehp_check_link_status() which does not emit a message. Adding one allows dropping the "Failed to check link status" message emitted by board_added() if pciehp_check_link_status() returns a non-zero integer. * Tone down all messages in pciehp_check_link_status() to KERN_INFO severity and rephrase them to look as innocuous as possible. To this end, move the message emitted by pcie_wait_for_link_delay() to its callers. As a result, Stuart Hayes' splat becomes: KERN_INFO pcieport 0000:3c:06.0: pciehp: Slot(180): Link Up KERN_INFO pcieport 0000:3c:06.0: pciehp: Slot(180): Cannot train link: status 0x0001 Dongdong Liu's splat becomes: KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): Card present KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): No link The messages now merely serve as information that presence or link bits were set a little longer than expected. Bringup failures which are not false positives are still reported, albeit no longer at KERN_ERR severity. Link: https://lore.kernel.org/linux-pci/20200310182100.102987-1-stuart.w.hayes@gmail.com/ Link: https://lore.kernel.org/linux-pci/1547649064-19019-1-git-send-email-liudongdong3@huawei.com/ Link: https://lore.kernel.org/r/b45e46fd8a6aa6930aaac9d7718c2e4b787a4e5e.1595935071.git.lukas@wunner.de Reported-by: Stuart Hayes <stuart.w.hayes@gmail.com> Reported-by: Dongdong Liu <liudongdong3@huawei.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2020-06-01PCI/DPC: Print IRQ number used by portYicong Yang1-0/+1
Print IRQ number used by DPC port, like AER/PME does. It provides convenience to track DPC interrupts counts of certain port from /proc/interrupts. Link: https://lore.kernel.org/r/1589018214-52752-1-git-send-email-yangyicong@hisilicon.com Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-06-01PCI/AER: Remove HEST/FIRMWARE_FIRST parsing for AER ownershipKuppuswamy Sathyanarayanan1-1/+1
Commit c100beb9ccfb ("PCI/AER: Use only _OSC to determine AER ownership") removed the use of HEST in determining AER ownership, but the AER driver still used HEST to verify AER ownership in some of its APIs. Per the ACPI spec v6.3, sec 18.3.2.4, some HEST table entries contain a FIRMWARE_FIRST bit, but that bit does not tell us anything about ownership of the AER capability. Remove parsing of HEST to look for FIRMWARE_FIRST. Add pcie_aer_is_native() for the places that need to know whether the OS owns the AER capability. [bhelgaas: commit log, reorder patch, remove unused __aer_firmware_first] Link: https://lore.kernel.org/r/9a37f53a4e6ff4942ff8e18dbb20b00e16c47341.1590534843.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-03-28PCI/AER: Rationalize error status register clearingKuppuswamy Sathyanarayanan1-1/+1
The AER interfaces to clear error status registers were a confusing mess: - pci_cleanup_aer_uncorrect_error_status() cleared non-fatal errors from the Uncorrectable Error Status register. - pci_aer_clear_fatal_status() cleared fatal errors from the Uncorrectable Error Status register. - pci_cleanup_aer_error_status_regs() cleared the Root Error Status register (for Root Ports), the Uncorrectable Error Status register, and the Correctable Error Status register. Rename them to make them consistent: From To ---------------------------------------- ------------------------------- pci_cleanup_aer_uncorrect_error_status() pci_aer_clear_nonfatal_status() pci_aer_clear_fatal_status() pci_aer_clear_fatal_status() pci_cleanup_aer_error_status_regs() pci_aer_clear_status() Since pci_cleanup_aer_error_status_regs() (renamed to pci_aer_clear_status()) is only used within drivers/pci/, move the declaration from <linux/aer.h> to drivers/pci/pci.h. [bhelgaas: commit log, add renames] Link: https://lore.kernel.org/r/d1310a75dc3d28f7e8da4e99c45fbd3e60fe238e.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-03-28PCI/DPC: Expose dpc_process_error(), dpc_reset_link() for use by EDRKuppuswamy Sathyanarayanan1-3/+9
If firmware controls DPC, it is generally responsible for managing the DPC capability and events, and the OS should not access the DPC capability. However, if firmware controls DPC and both the OS and the platform support Error Disconnect Recover (EDR) notifications, the OS EDR notify handler is responsible for recovery, and the notify handler may read/write the DPC capability until it clears the DPC Trigger Status bit. See [1], sec 4.5.1, table 4-6. Expose some DPC error handling functions so they can be used by the EDR notify handler. [1] Downstream Port Containment Related Enhancements ECN, Jan 28, 2019, affecting PCI Firmware Specification, Rev. 3.2 https://members.pcisig.com/wg/PCI-SIG/document/12888 Link: https://lore.kernel.org/r/e9000bb15b3a4293e81d98bb29ead7c84a6393c9.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-03-28PCI/DPC: Cache DPC capabilities in pci_init_capabilities()Kuppuswamy Sathyanarayanan1-12/+21
Since Error Disconnect Recover needs to use DPC error handling routines even if the OS doesn't have control of DPC, move the initalization and caching of DPC capabilities from the DPC driver to pci_init_capabilities(). Link: https://lore.kernel.org/r/5888380657c8b9551675b5dbd48e370e4fd2703d.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-03-28PCI/ERR: Remove service dependency in pcie_do_recovery()Kuppuswamy Sathyanarayanan1-2/+1
Previously we passed the PCIe service type parameter to pcie_do_recovery(), where reset_link() looked up the underlying pci_port_service_driver and its .reset_link() function pointer. Instead of using this roundabout way, we can just pass the driver-specific .reset_link() callback function when calling pcie_do_recovery() function. This allows us to call pcie_do_recovery() from code that is not a PCIe port service driver, e.g., Error Disconnect Recover (EDR) support. Remove pcie_port_find_service() and pcie_port_service_driver.reset_link since they are now unused. Link: https://lore.kernel.org/r/60e02b87b526cdf2930400059d98704bf0a147d1.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-03-28PCI/DPC: Move DPC data into struct pci_devBjorn Helgaas1-72/+31
We only need 25 bits of data for DPC, so I don't think it's worth the complexity of allocating and keeping track of the struct dpc_dev separately from the pci_dev. Move that data into the struct pci_dev. Link: https://lore.kernel.org/r/98323eaa18080adbe5bb30846862f09f8722d4b3.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-10-25PCI/DPC: Add "pcie_ports=dpc-native" to allow DPC without AER controlOlof Johansson1-1/+1
Prior to eed85ff4c0da7 ("PCI/DPC: Enable DPC only if AER is available"), Linux handled DPC events regardless of whether firmware had granted it ownership of AER or DPC, e.g., via _OSC. PCIe r5.0, sec 6.2.10, recommends that the OS link control of DPC to control of AER, so after eed85ff4c0da7, Linux handles DPC events only if it has control of AER. On platforms that do not grant OS control of AER via _OSC, Linux DPC handling worked before eed85ff4c0da7 but not after. To make Linux DPC handling work on those platforms the same way they did before, add a "pcie_ports=dpc-native" kernel parameter that makes Linux handle DPC events regardless of whether it has control of AER. [bhelgaas: commit log, move pcie_ports_dpc_native to drivers/pci/] Link: https://lore.kernel.org/r/20191023192205.97024-1-olof@lixom.net Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-05-10PCI/DPC: Log messages with pci_dev, not pcie_deviceFrederick Lawler1-19/+18
Log messages with pci_dev, not pcie_device. Factor out common message prefixes with dev_fmt(). Example output change: - dpc 0000:00:01.1:pcie008: DPC error containment capabilities... + pcieport 0000:00:01.1: DPC: error containment capabilities... Link: https://lore.kernel.org/lkml/20190509141456.223614-4-helgaas@kernel.org Signed-off-by: Frederick Lawler <fred@fredlawl.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Keith Busch <keith.busch@intel.com>
2019-02-22PCI/DPC: Fix print AER status in DPC event handlingDongdong Liu1-1/+26
Previously dpc_handler() called aer_get_device_error_info() without initializing info->severity, so aer_get_device_error_info() relied on uninitialized data. Add dpc_get_aer_uncorrect_severity() to read the port's AER status, mask, and severity registers and set info->severity. Also, clear the port's AER fatal error status bits. Fixes: 8aefa9b0d910 ("PCI/DPC: Print AER status in DPC event handling") Signed-off-by: Dongdong Liu <liudongdong3@huawei.com> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Cc: stable@vger.kernel.org # v4.19+
2018-10-03PCI: Make link active reporting detection genericKeith Busch1-1/+3
The spec has timing requirements when waiting for a link to become active after a conventional reset. Implement those hard delays when waiting for an active link so pciehp and dpc drivers don't need to duplicate this. For devices that don't support data link layer active reporting, wait the fixed time recommended by the PCIe spec. Signed-off-by: Keith Busch <keith.busch@intel.com> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org>
2018-09-26PCI/ERR: Handle fatal error recoveryKeith Busch1-2/+2
We don't need to be paranoid about the topology changing while handling an error. If the device has changed in a hotplug capable slot, we can rely on the presence detection handling to react to a changing topology. Restore the fatal error handling behavior that existed before merging DPC with AER with 7e9084b36740 ("PCI/AER: Handle ERR_FATAL with removal and re-enumeration of devices"). Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org>
2018-09-21PCI/DPC: Save and restore config stateKeith Busch1-6/+55
This patch provides DPC save and restore capabilities. This is necessary for the driver to observe DPC events in the event the configuration space needs to be restored after a reset. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org>
2018-09-20PCI: portdrv: Initialize service drivers directlyKeith Busch1-2/+1
The PCI port driver saves the PCI state after initializing the device with the applicable service devices. This was, however, before the service drivers were even registered because PCI probe happens before the device_initcall initialized those service drivers. The config space state that the services set up were not being saved. The end result would cause PCI devices to not react to events that the drivers think they did if the PCI state ever needed to be restored. Fix this by changing the service drivers from using the init calls to having the portdrv driver calling the services directly. This will get the state saved as desired, while making the relationship between the port driver and the services under it more explicit in the code. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org>
2018-07-20PCI/DPC: Remove indirection waiting for inactive linkKeith Busch1-8/+2
Simplify waiting for the contained link to become inactive, removing the indirection to a unnecessary DPC-specific handler. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org> Reviewed-by: Oza Pawandeep <poza@codeaurora.org>
2018-07-20PCI/DPC: Use threaded IRQ for bottom half handlingKeith Busch1-7/+8
Remove the work struct that was being used to handle a DPC event and use a threaded IRQ instead. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org> Reviewed-by: Oza Pawandeep <poza@codeaurora.org>
2018-07-20PCI/DPC: Print AER status in DPC event handlingKeith Busch1-0/+6
A DPC enabled device suppresses ERR_(NON)FATAL messages, preventing the AER handler from reporting error details. If the DPC trigger reason says the downstream port detected the error, collect the AER uncorrectable status for logging, then clear the status. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org> Reviewed-by: Oza Pawandeep <poza@codeaurora.org>
2018-07-20PCI/DPC: Remove rp_pio_status from dpc structKeith Busch1-12/+5
We don't need to save the rp pio status across multiple contexts as all DPC event handling occurs in a single work queue context. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org> Reviewed-by: Oza Pawandeep <poza@codeaurora.org>
2018-07-20PCI/DPC: Defer event handling to work queueKeith Busch1-24/+20
Move all event handling to the existing work queue, which will make it simpler to pass event information to the handler. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org> Reviewed-by: Oza Pawandeep <poza@codeaurora.org>
2018-07-20PCI/DPC: Leave interrupts enabled while handling eventKeith Busch1-18/+5
Now that the DPC driver clears the interrupt status before exiting the IRQ handler, we don't need to abuse the DPC control register to know if a shared interrupt is for a new DPC event: a DPC port can not trigger a second interrupt until the host clears the trigger status later in the work queue handler. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org> Reviewed-by: Oza Pawandeep <poza@codeaurora.org>
2018-06-11PCI/AER: Move pcie_aer_get_firmware_first() to portdrv.hBjorn Helgaas1-1/+0
Move pcie_aer_get_firmware_first() to portdrv.h, where it can be more easily shared between AER and DPC. Then DPC no longer needs to include aer/aerdrv.h. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Keith Busch <keith.busch@intel.com>
2018-06-07Merge branch 'pci/dpc'Bjorn Helgaas1-1/+4
- clear interrupt status in top half to avoid interrupt storm (Oza Pawandeep) * pci/dpc: PCI/DPC: Clear interrupt status in interrupt handler top half
2018-06-03PCI/DPC: Use the generic pcie_do_fatal_recovery() pathOza Pawandeep1-20/+33
Our goal is to handle ERR_FATAL errors similarly, whether they are reported via AER or via DPC. A previous commit changed AER so it handles ERR_FATAL by calling driver .remove() methods and resetting the Link. DPC already does that (although the Link reset is done automatically by hardware and happens before we call the driver .remove() methods). Restructure the DPC code so it calls the same pcie_do_fatal_recovery() interface used by AER. This makes it clearer that we want to use the same path. Implement the .reset_link() method used by pcie_do_fatal_recovery(). For DPC, the actual reset is done automatically by hardware, so we really only have to wait for the Link to be inactive, then release the Port from DPC. Signed-off-by: Oza Pawandeep <poza@codeaurora.org> [bhelgaas: changelog, DPC_FATAL is not a bitfield, can be sequential] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-06-03PCI/DPC: Disable ERR_NONFATAL handling by DPCOza Pawandeep1-2/+2
PCIe ERR_NONFATAL errors mean a particular transaction is unreliable but the Link is otherwise fully functional (PCIe r4.0, sec 6.2.2). The AER driver handles these by logging the error details and calling driver-supplied pci_error_handlers callbacks. It does not reset downstream devices, does not remove them from the PCI subsystem, does not re-enumerate them, and does not call their driver .remove() or .probe() methods. But DPC driver previously enabled DPC on ERR_NONFATAL, so if the hardware supports DPC, these errors caused a Link reset (performed automatically by the hardware), followed by the DPC driver removing affected devices (which calls their .remove() methods), bringing the Link back up, and re-enumerating (which calls driver .probe() methods). Disable ERR_NONFATAL DPC triggering so these errors will only be handled by AER. This means drivers won't have to deal with different usage of their pci_error_handlers callbacks and .probe() and .remove() methods based on whether the platform has DPC support. Signed-off-by: Oza Pawandeep <poza@codeaurora.org> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-05-18PCI: Add generic pcie_wait_for_link() interfaceOza Pawandeep1-11/+1
Clients such as hotplug and Downstream Port Containment (DPC) both need to wait until a link becomes active or inactive. Add a generic pcie_wait_link_active() interface and use it instead of duplicating the code. Signed-off-by: Oza Pawandeep <poza@codeaurora.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Keith Busch <keith.busch@intel.com>
2018-05-16PCI/DPC: Clear interrupt status in interrupt handler top halfOza Pawandeep1-1/+4
The generic IRQ handling code ensures that an interrupt handler runs with its interrupt masked or disabled. If the interrupt is level-triggered, the interrupt handler must tell its device to stop asserting the interrupt before returning. If it doesn't, we will immediately take the interrupt again when the handler returns and the generic code unmasks the interrupt. The driver doesn't know whether its interrupt is edge- or level-triggered, so it must clear its interrupt source directly in its interrupt handler. Previously we cleared the DPC interrupt status in the bottom half, i.e., in deferred work, which can cause an interrupt storm if the DPC interrupt happens to be level-triggered, e.g., if we're using INTx instead of MSI. Clear the DPC interrupt status bit in the interrupt handler, not in the deferred work. Signed-off-by: Oza Pawandeep <poza@codeaurora.org> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <helgaas@kernel.org> Reviewed-by: Keith Busch <keith.busch@intel.com>
2018-04-01PCI/DPC: Rename from pcie-dpc.c to dpc.cBjorn Helgaas1-0/+307
Rename pcie-dpc.c to dpc.c. The path "drivers/pci/pcie/pcie-dpc.c" has more occurrences of "pci" than necessary. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>