kernel.git/drivers/pci/pcie, branch linux-5.4.y

PCI/portdrv: Only disable pciehp interrupts early when needed

2025-04-10T12:29:40Z

[ Upstream commit 9d7db4db19827380e225914618c0c1bf435ed2f5 ] Firmware developers reported that Linux issues two PCIe hotplug commands in very short intervals on an ARM server, which doesn't comply with the PCIe spec. According to PCIe r6.1, sec 6.7.3.2, if the Command Completed event is supported, software must wait for a command to complete or wait at least 1 second before sending a new command. In the failure case, the first PCIe hotplug command is from get_port_device_capability(), which sends a command to disable PCIe hotplug interrupts without waiting for its completion, and the second command comes from pcie_enable_notification() of pciehp driver, which enables hotplug interrupts again. Fix this by only disabling the hotplug interrupts when the pciehp driver is not enabled. Link: https://lore.kernel.org/r/20250303023630.78397-1-feng.tang@linux.alibaba.com Fixes: 2bd50dd800b5 ("PCI: PCIe: Disable PCIe port services during port initialization") Suggested-by: Lukas Wunner Signed-off-by: Feng Tang [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Reviewed-by: Kuppuswamy Sathyanarayanan Signed-off-by: Sasha Levin

PCI/ASPM: Fix link state exit during switch upstream function removal

2025-04-10T12:29:40Z

[ Upstream commit cbf937dcadfd571a434f8074d057b32cd14fbea5 ] Before 456d8aa37d0f ("PCI/ASPM: Disable ASPM on MFD function removal to avoid use-after-free"), we would free the ASPM link only after the last function on the bus pertaining to the given link was removed. That was too late. If function 0 is removed before sibling function, link->downstream would point to free'd memory after. After above change, we freed the ASPM parent link state upon any function removal on the bus pertaining to a given link. That is too early. If the link is to a PCIe switch with MFD on the upstream port, then removing functions other than 0 first would free a link which still remains parent_link to the remaining downstream ports. The resulting GPFs are especially frequent during hot-unplug, because pciehp removes devices on the link bus in reverse order. On that switch, function 0 is the virtual P2P bridge to the internal bus. Free exactly when function 0 is removed -- before the parent link is obsolete, but after all subordinate links are gone. Link: https://lore.kernel.org/r/e12898835f25234561c9d7de4435590d957b85d9.1734924854.git.dns@arista.com Fixes: 456d8aa37d0f ("PCI/ASPM: Disable ASPM on MFD function removal to avoid use-after-free") Signed-off-by: Daniel Stodden Signed-off-by: Bjorn Helgaas [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński Signed-off-by: Sasha Levin

PCI/AER: Disable AER service on suspend

2025-01-09T12:23:26Z

[ Upstream commit 5afc2f763edc5daae4722ee46fea4e627d01fa90 ] If the link is powered off during suspend, electrical noise may cause errors that are logged via AER. If the AER interrupt is enabled and shares an IRQ with PME, that causes a spurious wakeup during suspend. Disable the AER interrupt during suspend to prevent this. Clear error status before re-enabling IRQ interrupts during resume so we don't get an interrupt for errors that occurred during the suspend/resume process. Link: https://bugzilla.kernel.org/show_bug.cgi?id=209149 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216295 Link: https://bugzilla.kernel.org/show_bug.cgi?id=218090 Link: https://lore.kernel.org/r/20240416043225.1462548-2-kai.heng.feng@canonical.com Signed-off-by: Kai-Heng Feng [bhelgaas: drop pci_ancestor_pr3_present() etc, commit log] Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin

PCI/DPC: Print all TLP Prefixes, not just the first

2024-03-26T22:22:19Z

[ Upstream commit 6568d82512b0a64809acff3d7a747362fa4288c8 ] The TLP Prefix Log Register consists of multiple DWORDs (PCIe r6.1 sec 7.9.14.13) but the loop in dpc_process_rp_pio_error() keeps reading from the first DWORD, so we print only the first PIO TLP Prefix (duplicated several times), and we never print the second, third, etc., Prefixes. Add the iteration count based offset calculation into the config read. Fixes: f20c4ea49ec4 ("PCI/DPC: Add eDPC support") Link: https://lore.kernel.org/r/20240118110815.3867-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen [bhelgaas: add user-visible details to commit log] Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin

PCI/AER: Decode Requester ID when no error info found

2024-02-23T07:25:03Z

[ Upstream commit 1291b716bbf969e101d517bfb8ba18d958f758b8 ] When a device with AER detects an error, it logs error information in its own AER Error Status registers. It may send an Error Message to the Root Port (RCEC in the case of an RCiEP), which logs the fact that an Error Message was received (Root Error Status) and the Requester ID of the message source (Error Source Identification). aer_print_port_info() prints the Requester ID from the Root Port Error Source in the usual Linux "bb:dd.f" format, but when find_source_device() finds no error details in the hierarchy below the Root Port, it printed the raw Requester ID without decoding it. Decode the Requester ID in the usual Linux format so it matches other messages. Sample message changes: - pcieport 0000:00:1c.5: AER: Correctable error received: 0000:00:1c.5 - pcieport 0000:00:1c.5: AER: can't find device of ID00e5 + pcieport 0000:00:1c.5: AER: Correctable error message received from 0000:00:1c.5 + pcieport 0000:00:1c.5: AER: found no error details for 0000:00:1c.5 Link: https://lore.kernel.org/r/20231206224231.732765-3-helgaas@kernel.org Signed-off-by: Bjorn Helgaas Reviewed-by: Jonathan Cameron Reviewed-by: Kuppuswamy Sathyanarayanan Signed-off-by: Sasha Levin

PCI/ASPM: Use RMW accessors for changing LNKCTL

2023-09-23T08:59:47Z

[ Upstream commit e09060b3b6b4661278ff8e1b7b81a37d5ea86eae ] Don't assume that the device is fully under the control of ASPM and use RMW capability accessors which do proper locking to avoid losing concurrent updates to the register values. If configuration fails in pcie_aspm_configure_common_clock(), the function attempts to restore the old PCI_EXP_LNKCTL_CCC settings. Store only the old PCI_EXP_LNKCTL_CCC bit for the relevant devices rather than the content of the whole LNKCTL registers. It aligns better with how pcie_lnkctl_clear_and_set() expects its parameter and makes the code more obvious to understand. Suggested-by: Lukas Wunner Fixes: 2a42d9dba784 ("PCIe: ASPM: Break out of endless loop waiting for PCI config bits to switch") Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support") Link: https://lore.kernel.org/r/20230717120503.15276-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Acked-by: "Rafael J. Wysocki" Signed-off-by: Sasha Levin

PCI/ASPM: Avoid link retraining race

2023-08-11T09:53:45Z

[ Upstream commit e7e39756363ad5bd83ddeae1063193d0f13870fd ] PCIe r6.0.1, sec 7.5.3.7, recommends setting the link control parameters, then waiting for the Link Training bit to be clear before setting the Retrain Link bit. This avoids a race where the LTSSM may not use the updated parameters if it is already in the midst of link training because of other normal link activity. Wait for the Link Training bit to be clear before toggling the Retrain Link bit to ensure that the LTSSM uses the updated link control parameters. [bhelgaas: commit log, return 0 (success)/-ETIMEDOUT instead of bool for both pcie_wait_for_retrain() and the existing pcie_retrain_link()] Suggested-by: Lukas Wunner Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support") Link: https://lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

PCI/ASPM: Factor out pcie_wait_for_retrain()

2023-08-11T09:53:45Z

[ Upstream commit 9c7f136433d26592cb4d9cd00b4e15c33d9797c6 ] Factor pcie_wait_for_retrain() out from pcie_retrain_link(). No functional change intended. [bhelgaas: split out from https: //lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com] Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Stable-dep-of: e7e39756363a ("PCI/ASPM: Avoid link retraining race") Signed-off-by: Sasha Levin

PCI/ASPM: Return 0 or -ETIMEDOUT from pcie_retrain_link()

2023-08-11T09:53:45Z

[ Upstream commit f5297a01ee805d7fa569d288ed65fc0f9ac9b03d ] "pcie_retrain_link" is not a question with a true/false answer, so "bool" isn't quite the right return type. Return 0 for success or -ETIMEDOUT if the retrain failed. No functional change intended. [bhelgaas: based on Ilpo's patch below] Link: https://lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Bjorn Helgaas Stable-dep-of: e7e39756363a ("PCI/ASPM: Avoid link retraining race") Signed-off-by: Sasha Levin

PCI/ASPM: Disable ASPM on MFD function removal to avoid use-after-free

2023-07-27T06:37:16Z

[ Upstream commit 456d8aa37d0f56fc9e985e812496e861dcd6f2f2 ] Struct pcie_link_state->downstream is a pointer to the pci_dev of function 0. Previously we retained that pointer when removing function 0, and subsequent ASPM policy changes dereferenced it, resulting in a use-after-free warning from KASAN, e.g.: # echo 1 > /sys/bus/pci/devices/0000:03:00.0/remove # echo powersave > /sys/module/pcie_aspm/parameters/policy BUG: KASAN: slab-use-after-free in pcie_config_aspm_link+0x42d/0x500 Call Trace: kasan_report+0xae/0xe0 pcie_config_aspm_link+0x42d/0x500 pcie_aspm_set_policy+0x8e/0x1a0 param_attr_store+0x162/0x2c0 module_attr_store+0x3e/0x80 PCIe spec r6.0, sec 7.5.3.7, recommends that software program the same ASPM Control value in all functions of multi-function devices. Disable ASPM and free the pcie_link_state when any child function is removed so we can discard the dangling pcie_link_state->downstream pointer and maintain the same ASPM Control configuration for all functions. [bhelgaas: commit log and comment] Debugged-by: Zongquan Qin Suggested-by: Bjorn Helgaas Fixes: b5a0a9b59c81 ("PCI/ASPM: Read and set up L1 substate capabilities") Link: https://lore.kernel.org/r/20230507034057.20970-1-dinghui@sangfor.com.cn Signed-off-by: Ding Hui Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin