linux-toradex.git/drivers/pci/ats.c, branch v4.4.117

PCI: Remove pci_ats_enabled()

2015-08-13T20:59:59+00:00

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

2015-08-13T20:59:58+00:00

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

2015-08-13T20:57:30+00:00

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

2015-08-13T20:57:23+00:00

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()

2015-08-13T20:57:23+00:00

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

2015-08-13T20:57:22+00:00

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

2015-08-13T20:57:21+00:00

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

2015-08-13T20:57:21+00:00

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

PCI: Removed unused parts of Page Request Interface support

2014-01-10T21:00:47+00:00

My philosophy is unused code is dead code.  And dead code is subject to bit
rot and is a likely source of bugs.  Use it or lose it.

This reverts parts of c320b976d783 ("PCI: Add implementation for PRI
capability"), removing these interfaces:

    pci_pri_enabled()
    pci_pri_stopped()
    pci_pri_status()

[bhelgaas: split to separate patch]
Signed-off-by: Stephen Hemminger 
Signed-off-by: Bjorn Helgaas 
CC: Joerg Roedel

PCI: Fix whitespace, capitalization, and spelling errors

2013-11-14T18:28:18+00:00

Fix whitespace, capitalization, and spelling errors.  No functional change.
I know "busses" is not an error, but "buses" was more common, so I used it
consistently.

Signed-off-by: Marta Rybczynska  (pci_reset_bridge_secondary_bus())
Signed-off-by: Bjorn Helgaas 
Acked-by: Rafael J. Wysocki