linux/drivers/pci, branch v5.2

PCI: PM: Avoid skipping bus-level PM on platforms without ACPI

2019-06-26T21:51:56Z

There are platforms that do not call pm_set_suspend_via_firmware(), so pm_suspend_via_firmware() returns 'false' on them, but the power states of PCI devices (PCIe ports in particular) are changed as a result of powering down core platform components during system-wide suspend. Thus the pm_suspend_via_firmware() checks in pci_pm_suspend_noirq() and pci_pm_resume_noirq() introduced by commit 3e26c5feed2a ("PCI: PM: Skip devices in D0 for suspend-to- idle") are not sufficient to determine that devices left in D0 during suspend will remain in D0 during resume and so the bus-level power management can be skipped for them. For this reason, introduce a new global suspend flag, PM_SUSPEND_FLAG_NO_PLATFORM, set it for suspend-to-idle only and replace the pm_suspend_via_firmware() checks mentioned above with checks against this flag. Fixes: 3e26c5feed2a ("PCI: PM: Skip devices in D0 for suspend-to-idle") Reported-by: Jon Hunter Tested-by: Jon Hunter Signed-off-by: Rafael J. Wysocki Tested-by: Mika Westerberg Reviewed-by: Mika Westerberg

Merge tag 'pci-v5.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2019-06-22T16:42:29Z

Pull PCI fix from Bjorn Helgaas: "If an IOMMU is present, ignore the P2PDMA whitelist we added for v5.2 because we don't yet know how to support P2PDMA in that case (Logan Gunthorpe)" * tag 'pci-v5.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: PCI/P2PDMA: Ignore root complex whitelist when an IOMMU is present

PCI/P2PDMA: Ignore root complex whitelist when an IOMMU is present

2019-06-19T21:43:42Z

Presently, there is no path to DMA map P2PDMA memory, so if a TLP targeting this memory hits the root complex and an IOMMU is present, the IOMMU will reject the transaction, even if the RC would support P2PDMA. So until the kernel knows to map these DMA addresses in the IOMMU, we should not enable the whitelist when an IOMMU is present. Link: https://lore.kernel.org/linux-pci/20190522201252.2997-1-logang@deltatee.com/ Fixes: 0f97da831026 ("PCI/P2PDMA: Allow P2P DMA between any devices under AMD ZEN Root Complex") Signed-off-by: Logan Gunthorpe Reviewed-by: Christian König Signed-off-by: Bjorn Helgaas Cc: Christoph Hellwig

Merge tag 'pm-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2019-06-19T18:44:04Z

Pull power management fix from Rafael Wysocki: "Prevent PCI bridges in general (and PCIe ports in particular) from being put into low-power states during system-wide suspend transitions if there are any devices in D0 below them and refine the handling of PCI devices in D0 during suspend-to-idle cycles" * tag 'pm-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PCI: PM: Skip devices in D0 for suspend-to-idle

mm/devm_memremap_pages: fix final page put race

2019-06-14T03:34:56Z

Logan noticed that devm_memremap_pages_release() kills the percpu_ref drops all the page references that were acquired at init and then immediately proceeds to unplug, arch_remove_memory(), the backing pages for the pagemap. If for some reason device shutdown actually collides with a busy / elevated-ref-count page then arch_remove_memory() should be deferred until after that reference is dropped. As it stands the "wait for last page ref drop" happens *after* devm_memremap_pages_release() returns, which is obviously too late and can lead to crashes. Fix this situation by assigning the responsibility to wait for the percpu_ref to go idle to devm_memremap_pages() with a new ->cleanup() callback. Implement the new cleanup callback for all devm_memremap_pages() users: pmem, devdax, hmm, and p2pdma. Link: http://lkml.kernel.org/r/155727339156.292046.5432007428235387859.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 41e94a851304 ("add devm_memremap_pages") Signed-off-by: Dan Williams Reported-by: Logan Gunthorpe Reviewed-by: Ira Weiny Reviewed-by: Logan Gunthorpe Cc: Bjorn Helgaas Cc: "Jérôme Glisse" Cc: Christoph Hellwig Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

PCI/P2PDMA: track pgmap references per resource, not globally

2019-06-14T03:34:56Z

In preparation for fixing a race between devm_memremap_pages_release() and the final put of a page from the device-page-map, allocate a percpu-ref per p2pdma resource mapping. Link: http://lkml.kernel.org/r/155727338646.292046.9922678317501435597.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Reviewed-by: Ira Weiny Reviewed-by: Logan Gunthorpe Cc: Bjorn Helgaas Cc: Christoph Hellwig Cc: Greg Kroah-Hartman Cc: "Jérôme Glisse" Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

PCI/P2PDMA: fix the gen_pool_add_virt() failure path

2019-06-14T03:34:56Z

The pci_p2pdma_add_resource() implementation immediately frees the pgmap if gen_pool_add_virt() fails. However, that means that when @dev triggers a devres release devm_memremap_pages_release() will crash trying to access the freed @pgmap. Use the new devm_memunmap_pages() to manually free the mapping in the error path. Link: http://lkml.kernel.org/r/155727337603.292046.13101332703665246702.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Fixes: 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory") Reviewed-by: Ira Weiny Acked-by: Bjorn Helgaas Reviewed-by: Logan Gunthorpe Cc: Christoph Hellwig Cc: Greg Kroah-Hartman Cc: "Jérôme Glisse" Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

PCI: PM: Skip devices in D0 for suspend-to-idle

2019-06-13T22:03:27Z

Commit d491f2b75237 ("PCI: PM: Avoid possible suspend-to-idle issue") attempted to avoid a problem with devices whose drivers want them to stay in D0 over suspend-to-idle and resume, but it did not go as far as it should with that. Namely, first of all, the power state of a PCI bridge with a downstream device in D0 must be D0 (based on the PCI PM spec r1.2, sec 6, table 6-1, if the bridge is not in D0, there can be no PCI transactions on its secondary bus), but that is not actively enforced during system-wide PM transitions, so use the skip_bus_pm flag introduced by commit d491f2b75237 for that. Second, the configuration of devices left in D0 (whatever the reason) during suspend-to-idle need not be changed and attempting to put them into D0 again by force is pointless, so explicitly avoid doing that. Fixes: d491f2b75237 ("PCI: PM: Avoid possible suspend-to-idle issue") Reported-by: Kai-Heng Feng Signed-off-by: Rafael J. Wysocki Reviewed-by: Mika Westerberg Tested-by: Kai-Heng Feng

PCI: PM: Avoid possible suspend-to-idle issue

2019-05-27T08:55:08Z

If a PCI driver leaves the device handled by it in D0 and calls pci_save_state() on the device in its ->suspend() or ->suspend_late() callback, it can expect the device to stay in D0 over the whole s2idle cycle. However, that may not be the case if there is a spurious wakeup while the system is suspended, because in that case pci_pm_suspend_noirq() will run again after pci_pm_resume_noirq() which calls pci_restore_state(), via pci_pm_default_resume_early(), so state_saved is cleared and the second iteration of pci_pm_suspend_noirq() will invoke pci_prepare_to_sleep() which may change the power state of the device. To avoid that, add a new internal flag, skip_bus_pm, that will be set by pci_pm_suspend_noirq() when it runs for the first time during the given system suspend-resume cycle if the state of the device has been saved already and the device is still in D0. Setting that flag will cause the next iterations of pci_pm_suspend_noirq() to set state_saved for pci_pm_resume_noirq(), so that it always restores the device state from the originally saved data, and avoid calling pci_prepare_to_sleep() for the device. Fixes: 33e4f80ee69b ("ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle") Signed-off-by: Rafael J. Wysocki Reviewed-by: Keith Busch Reviewed-by: Mika Westerberg

ACPI/PCI: PM: Add missing wakeup.flags.valid checks

2019-05-27T08:51:06Z

Both acpi_pci_need_resume() and acpi_dev_needs_resume() check if the current ACPI wakeup configuration of the device matches what is expected as far as system wakeup from sleep states is concerned, as reflected by the device_may_wakeup() return value for the device. However, they only should do that if wakeup.flags.valid is set for the device's ACPI companion, because otherwise the wakeup.prepare_count value for it is meaningless. Add the missing wakeup.flags.valid checks to these functions. Signed-off-by: Rafael J. Wysocki Reviewed-by: Mika Westerberg