Pull pci fix from Bjorn Helgaas: - Prevent a possible deadlock (reported by lockdep) when a driver relinquishes a pci_dev, another driver claims it, and one uses managed pcim_enable_device() and the other doesn't (Philipp Stanner) * tag 'pci-v6.11-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: PCI: Fix potential deadlock in pcim_intx()
25216afc9db5 ("PCI: Add managed pcim_intx()") moved the allocation step for
pci_intx()'s device resource from pcim_enable_device() to pcim_intx(). As
before, pcim_enable_device() sets pci_dev.is_managed to true; and it is
never set to false again.
Due to the lifecycle of a struct pci_dev, it can happen that a second
driver obtains the same pci_dev after a first driver ran. If one driver
uses pcim_enable_device() and the other doesn't, this causes the other
driver to run into managed pcim_intx(), which will try to allocate when
called for the first time.
Allocations might sleep, so calling pci_intx() while holding spinlocks
becomes then invalid, which causes lockdep warnings and could cause
deadlocks:
========================================================
WARNING: possible irq lock inversion dependency detected
6.11.0-rc6+ #59 Tainted: G W
--------------------------------------------------------
CPU 0/KVM/1537 just changed the state of lock:
ffffa0f0cff965f0 (&vdev->irqlock){-...}-{2:2}, at:
vfio_intx_handler+0x21/0xd0 [vfio_pci_core] but this lock took another,
HARDIRQ-unsafe lock in the past: (fs_reclaim){+.+.}-{0:0}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
local_irq_disable();
lock(&vdev->irqlock);
lock(fs_reclaim);
<Interrupt>
lock(&vdev->irqlock);
*** DEADLOCK ***
Have pcim_enable_device()'s release function, pcim_disable_device(), set
pci_dev.is_managed to false so that subsequent drivers using the same
struct pci_dev do not implicitly run into managed code.
Link: https://lore.kernel.org/r/20240905072556.11375-2-pstanner@redhat.com
Fixes: 25216afc9db5 ("PCI: Add managed pcim_intx()")
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Closes: https://lore.kernel.org/all/20240903094431.63551744.alex.williamson@redhat.com/
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Pull pci fixes from Bjorn Helgaas: - Unregister platform devices for child nodes when stopping a PCI device, even if the PCI core has already cleared the OF_POPULATED bit and of_platform_depopulate() doesn't do anything (Bartosz Golaszewski) - Rescan the bus from a separate thread so we don't deadlock when triggering rescan from sysfs (Bartosz Golaszewski) * tag 'pci-v6.11-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: PCI/pwrctl: Rescan bus on a separate thread PCI: Don't rely on of_platform_depopulate() for reused OF-nodes
If we trigger the bus rescan from sysfs, we'll try to lock the PCI rescan
mutex recursively and deadlock - the platform device will be populated and
probed on the same thread that handles the sysfs write.
Add a workqueue to the pwrctl code on which we schedule the rescan for
controlled PCI devices. While at it: add a new interface for initializing
the pwrctl context where we'd now assign the parent device address and
initialize the workqueue.
Link: https://lore.kernel.org/r/20240823093323.33450-3-brgl@bgdev.pl
Fixes: 4565d2652a37 ("PCI/pwrctl: Add PCI power control core code")
Reported-by: Konrad Dybcio <konradybcio@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
of_platform_depopulate() doesn't play nicely with reused OF nodes - it
ignores the ones that are not marked explicitly as populated and it may
happen that the PCI device goes away before the platform device in which
case the PCI core clears the OF_POPULATED bit.
Unconditionally unregister the platform devices for child nodes when
stopping the PCI device.
Link: https://lore.kernel.org/r/20240823093323.33450-2-brgl@bgdev.pl
Fixes: 8fb18619d910 ("PCI/pwrctl: Create platform devices for child OF nodes of the port node")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Pull pci fixes from Bjorn Helgaas: - Add Manivannan Sadhasivam as PCI native host bridge and endpoint driver reviewer (Manivannan Sadhasivam) - Disable MHI RAM data parity error interrupt for qcom SA8775P SoC to work around hardware erratum that causes a constant stream of interrupts (Manivannan Sadhasivam) - Don't try to fall back to qcom Operating Performance Points (OPP) support unless the platform actually supports OPP (Manivannan Sadhasivam) - Add imx@lists.linux.dev mailing list to MAINTAINERS for NXP layerscape and imx6 PCI controller drivers (Frank Li) * tag 'pci-v6.11-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: MAINTAINERS: PCI: Add NXP PCI controller mailing list imx@lists.linux.dev PCI: qcom: Use OPP only if the platform supports it PCI: qcom-ep: Disable MHI RAM data parity error interrupt for SA8775P SoC MAINTAINERS: Add Manivannan Sadhasivam as Reviewer for PCI native host bridge and endpoint drivers
With commit 5b6272e0efd5 ("PCI: qcom: Add OPP support to scale
performance"), OPP was used to control the interconnect and power domains
if the platform supported OPP. Also to maintain the backward compatibility
with platforms not supporting OPP but just ICC, the above mentioned commit
assumed that if ICC was not available on the platform, it would resort to
OPP.
Unfortunately, some old platforms don't support either ICC or OPP. On those
platforms, resorting to OPP in the absence of ICC throws below errors from
OPP core during suspend and resume:
qcom-pcie 1c08000.pcie: dev_pm_opp_set_opp: device opp doesn't exist
qcom-pcie 1c08000.pcie: _find_key: OPP table not found (-19)
Also, it doesn't make sense to invoke the OPP APIs when OPP is not
supported by the platform at all.
Add a "use_pm_opp" flag to identify whether OPP is supported and use it to
control invoking the OPP APIs.
Fixes: 5b6272e0efd5 ("PCI: qcom: Add OPP support to scale performance")
Link: https://lore.kernel.org/linux-pci/20240722131128.32470-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mayank Rana <quic_mrana@quicinc.com>
SA8775P SoC has support for the hardware parity check feature on the MHI
RAM (entity that holds MHI registers, etc.) But due to a hardware bug in
the parity check logic, the data parity error interrupt is getting
generated all the time when using MHI. So the hardware team has suggested
disabling the parity check error to work around the hardware bug.
Mask the parity error interrupt in PARF_INT_ALL_5_MASK register.
Fixes: 58d0d3e032b3 ("PCI: qcom-ep: Add support for SA8775P SOC")
Link: https://lore.kernel.org/linux-pci/20240808063057.7394-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The sysfs "attention" file normally controls the Slot Control Attention
Indicator with 0 (off), 1 (on), 2 (blink) settings.
576243b3f9ea ("PCI: pciehp: Allow exclusive userspace control of
indicators") added pciehp_set_raw_indicator_status() to allow userspace to
directly control all four bits in both the Attention Indicator and the
Power Indicator fields via the "attention" file.
This is used on Intel VMD bridges so utilities like "ledmon" can use sysfs
"attention" to control up to 16 indicators for NVMe device RAID status.
abaaac4845a0 ("PCI: hotplug: Use FIELD_GET/PREP()") broke this by masking
the sysfs data with PCI_EXP_SLTCTL_AIC, which discards the upper two bits
intended for the Power Indicator Control field (PCI_EXP_SLTCTL_PIC).
For NVMe devices behind an Intel VMD, ledmon settings that use the
PCI_EXP_SLTCTL_PIC bits, i.e., ATTENTION_REBUILD (0x5), ATTENTION_LOCATE
(0x7), ATTENTION_FAILURE (0xD), ATTENTION_OFF (0xF), no longer worked
correctly.
Mask with PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC to retain both the
Attention Indicator and the Power Indicator bits.
Fixes: abaaac4845a0 ("PCI: hotplug: Use FIELD_GET/PREP()")
Link: https://lore.kernel.org/r/20240722141440.7210-1-blazej.kucman@intel.com
Signed-off-by: Blazej Kucman <blazej.kucman@intel.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v6.7+
pci_intx() becomes managed if pcim_enable_device() has been called in
advance. Commit 25216afc9db5 ("PCI: Add managed pcim_intx()") changed this
behavior so that pci_intx() always leads to creation of a separate device
resource for itself, whereas earlier, a shared resource was used for all
PCI devres operations.
Unfortunately, pci_intx() seems to be used in some drivers' remove() paths;
in the managed case this causes a device resource to be created on driver
detach, which causes .probe() to fail if the driver is reloaded:
pci 0000:00:1f.2: Resources present before probing
Fix the regression by only redirecting pci_intx() to its managed twin
pcim_intx() if the pci_command changes.
Link: https://lore.kernel.org/r/20240725120729.59788-2-pstanner@redhat.com
Fixes: 25216afc9db5 ("PCI: Add managed pcim_intx()")
Reported-by: Damien Le Moal <dlemoal@kernel.org>
Closes: https://lore.kernel.org/all/b8f4ba97-84fc-4b7e-ba1a-99de2d9f0118@kernel.org/
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
[bhelgaas: add error message to commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>