kernel.git/drivers/pci/ats.c, branch linux-4.13.y

PCI: Restore PRI and PASID state after Function-Level Reset

2017-05-30T20:40:50Z

After a Function-Level Reset, PCI states need to be restored. Save PASID features and PRI reqs cached. [bhelgaas: search for capability only if PRI/PASID were enabled] Signed-off-by: CQ Tang Signed-off-by: Ashok Raj Signed-off-by: Bjorn Helgaas Cc: Joerg Roedel Cc: Jean-Phillipe Brucker Cc: David Woodhouse

PCI: Cache PRI and PASID bits in pci_dev

2017-05-30T20:39:15Z

Device drivers need to check if an IOMMU enabled ATS, PRI and PASID in order to know when they can use the SVM API. Cache PRI and PASID bits in the pci_dev structure, similarly to what is currently done for ATS. Signed-off-by: Jean-Philippe Brucker Signed-off-by: Bjorn Helgaas

PCI: Remove pci_ats_enabled()

2015-08-13T20:59:59Z

Remove pci_ats_enabled(). There are no callers outside the ATS code itself. We don't need to check ats_cap, because if we don't find an ATS capability, we'll never set ats_enabled. Signed-off-by: Bjorn Helgaas Reviewed-by: Joerg Roedel

PCI: Stop caching ATS Invalidate Queue Depth

2015-08-13T20:59:58Z

Stop caching the Invalidate Queue Depth in struct pci_dev. pci_ats_queue_depth() is typically called only once per device, and it returns a fixed value per-device, so callers who need the value frequently can cache it themselves. Signed-off-by: Bjorn Helgaas Reviewed-by: Joerg Roedel

PCI: Clean up ATS error handling

2015-08-13T20:57:30Z

There's no need to BUG() if we enable ATS when it's already enabled. We don't need to BUG() when disabling ATS on a device that doesn't support ATS or if it's already disabled. If ATS is enabled, certainly we found an ATS capability in the past, so it should still be there now. Clean up these error paths. Signed-off-by: Bjorn Helgaas Reviewed-by: Joerg Roedel

PCI: Use pci_physfn() rather than looking up physfn by hand

2015-08-13T20:57:23Z

Use the pci_physfn() helper rather than looking up physfn by hand. No functional change. Signed-off-by: Bjorn Helgaas Reviewed-by: Joerg Roedel

PCI: Inline the ATS setup code into pci_ats_init()

2015-08-13T20:57:23Z

The ATS setup code in ats_alloc_one() is only used by pci_ats_init(), so inline it there. No functional change. Signed-off-by: Bjorn Helgaas Reviewed-by: Joerg Roedel

PCI: Rationalize pci_ats_queue_depth() error checking

2015-08-13T20:57:22Z

We previously returned -ENODEV for devices that don't support ATS (except that we always returned 0 for VFs, whether or not they support ATS). For consistency, always return -EINVAL (not -ENODEV) if the device doesn't support ATS. Return zero for VFs that support ATS. Signed-off-by: Bjorn Helgaas Reviewed-by: Joerg Roedel

PCI: Embed ATS info directly into struct pci_dev

2015-08-13T20:57:21Z

The pci_ats struct is small and will get smaller, so I don't think it's worth allocating it separately from the pci_dev struct. Embed the ATS fields directly into struct pci_dev. Signed-off-by: Bjorn Helgaas Reviewed-by: Joerg Roedel

PCI: Allocate ATS struct during enumeration

2015-08-13T20:57:21Z

Previously, we allocated pci_ats structures when an IOMMU driver called pci_enable_ats(). An SR-IOV VF shares the STU setting with its PF, so when enabling ATS on the VF, we allocated a pci_ats struct for the PF if it didn't already have one. We held the sriov->lock to serialize threads concurrently enabling ATS on several VFS so only one would allocate the PF pci_ats. Gregor reported a deadlock here: pci_enable_sriov sriov_enable virtfn_add mutex_lock(dev->sriov->lock) # acquire sriov->lock pci_device_add device_add BUS_NOTIFY_ADD_DEVICE notifier chain iommu_bus_notifier amd_iommu_add_device # iommu_ops.add_device init_iommu_group iommu_group_get_for_dev iommu_group_add_device __iommu_attach_device amd_iommu_attach_device # iommu_ops.attach_device attach_device pci_enable_ats mutex_lock(dev->sriov->lock) # deadlock There's no reason to delay allocating the pci_ats struct, and if we allocate it for each device at enumeration-time, there's no need for locking in pci_enable_ats(). Allocate pci_ats struct during enumeration, when we initialize other capabilities. Note that this implementation requires ATS to be enabled on the PF first, before on any of the VFs because the PF controls the STU for all the VFs. Link: http://permalink.gmane.org/gmane.linux.kernel.iommu/9433 Reported-by: Gregor Dick Signed-off-by: Bjorn Helgaas Reviewed-by: Joerg Roedel