linux.git/drivers/pci/setup-res.c, branch v4.9

PCI: Don't attempt to claim shadow copies of ROM

2016-11-08T20:25:24+00:00

If we're using a shadow copy of a PCI device ROM, the shadow copy is in RAM
and the device never sees accesses to it and doesn't respond to it.  We
don't have to route the shadow range to the PCI device, and the device
doesn't have to claim the range.

Previously we treated the shadow copy as though it were the ROM BAR, and we
failed to claim it because the region wasn't routed to the device:

  pci 0000:01:00.0: Video device with shadowed ROM at [mem 0x000c0000-0x000dffff]
  pci_bus 0000:01: Allocating resources
  pci 0000:01:00.0: can't claim BAR 6 [mem 0x000c0000-0x000dffff]: no compatible bridge window

The failure path of pcibios_allocate_dev_rom_resource() cleared out the
resource start address, which also caused the following ioremap() warning:

  WARNING: CPU: 0 PID: 116 at /build/linux-akdJXO/linux-4.8.0/arch/x86/mm/ioremap.c:121 __ioremap_caller+0x1ec/0x370
  ioremap on RAM at 0x0000000000000000 - 0x000000000001ffff

Handle an option ROM shadow copy as RAM, without trying to insert it into
the iomem resource tree.

This fixes a regression caused by 0c0e0736acad ("PCI: Set ROM shadow
location in arch code, not in PCI core"), which appeared in v4.6.  The
regression causes video device initialization to fail.  This was reported
on AMD Turks, but it likely affects others as well.

Fixes: 0c0e0736acad ("PCI: Set ROM shadow location in arch code, not in PCI core")
Reported-and-tested-by: Vecu Bosseur 
Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1627496
Link: https://bugzilla.kernel.org/show_bug.cgi?id=175391
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1352272
Signed-off-by: Bjorn Helgaas 
CC: stable@vger.kernel.org	# v4.6+

PCI: Don't assign or reassign immutable resources

2016-03-08T18:14:31+00:00

IORESOURCE_PCI_FIXED means the resource can't be moved, so if it's set,
don't bother trying to assign or reassign the resource.

Signed-off-by: Bjorn Helgaas

Merge branches 'pci/aer', 'pci/hotplug', 'pci/misc', 'pci/msi', 'pci/resource' and 'pci/virtualization' into next

2015-11-02T21:57:03+00:00

* pci/aer:
  PCI/AER: Clear error status registers during enumeration and restore

* pci/hotplug:
  PCI: pciehp: Queue power work requests in dedicated function

* pci/misc:
  PCI: Turn off Request Attributes to avoid Chelsio T5 Completion erratum
  x86/PCI: Make pci_subsys_init() static
  PCI: Add builtin_pci_driver() to avoid registration boilerplate
  PCI: Remove unnecessary "if" statement

* pci/msi:
  x86/PCI: Don't alloc pcibios-irq when MSI is enabled
  PCI/MSI: Export all remapped MSIs to sysfs attributes
  PCI: Disable MSI on SiS 761

* pci/resource:
  sparc/PCI: Add mem64 resource parsing for root bus
  PCI: Expand Enhanced Allocation BAR output
  PCI: Make Enhanced Allocation bitmasks more obvious
  PCI: Handle Enhanced Allocation capability for SR-IOV devices
  PCI: Add support for Enhanced Allocation devices
  PCI: Add Enhanced Allocation register entries
  PCI: Handle IORESOURCE_PCI_FIXED when assigning resources
  PCI: Handle IORESOURCE_PCI_FIXED when sizing resources
  PCI: Clear IORESOURCE_UNSET when reverting to firmware-assigned address

* pci/virtualization:
  PCI: Fix sriov_enable() error path for pcibios_enable_sriov() failures
  PCI: Wait 1 second between disabling VFs and clearing NumVFs
  PCI: Reorder pcibios_sriov_disable()
  PCI: Remove VFs in reverse order if virtfn_add() fails
  PCI: Remove redundant validation of SR-IOV offset/stride registers
  PCI: Set SR-IOV NumVFs to zero after enumeration
  PCI: Enable SR-IOV ARI Capable Hierarchy before reading TotalVFs
  PCI: Don't try to restore VF BARs

PCI: Clear IORESOURCE_UNSET when reverting to firmware-assigned address

2015-09-23T19:14:02+00:00

If pci_assign_resource() fails to assign space for a BAR, we may restore
the BAR to whatever firmware left there at boot-time (this depends on
whether the arch implements pcibios_retrieve_fw_addr()).  The messages we
print are not as useful as they could be:

  pci 0000:00:01.0: BAR 15: assigned [mem 0xc0000000-0xc01fffff 64bit pref]
  pci 0000:01:00.0: BAR 0: no space for [mem size 0x10000000 pref]
  pci 0000:01:00.0: BAR 0: trying firmware assignment [mem size 0x10000000 pref]
  pci 0000:01:00.0: BAR 0: [mem size 0x10000000 pref] conflicts with PCI Bus 0000:00 [mem 0xc0000000-0xffffffff window]

The last two lines should contain the actual BAR address, not the size.
Clear IORESOURCE_UNSET so we print the address.  If requesting the
firmware-assigned resource fails, mark it IORESOURCE_UNSET again.

This is a cosmetic change to clarify the message: previously, if
pci_revert_fw_address() succeeded, pci_assign_resource() cleared
IORESOURCE_UNSET anyway, so this isn't really a functional change.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=85491#c50
Signed-off-by: Bjorn Helgaas

PCI: Don't try to restore VF BARs

2015-09-14T15:34:17+00:00

VF BARs are read-only zero, so updating VF BARs will not have any effect.
See the SR-IOV spec r1.1, sec 3.4.1.11.

Don't update VF BARs in pci_restore_bars().

This avoids spurious "BAR %d: error updating" messages that we see when
doing vfio pass-through after 6eb7018705de ("vfio-pci: Move idle devices to
D3hot power state").

[bhelgaas: changelog, fix whitespace]
Signed-off-by: Wei Yang 
Signed-off-by: Bjorn Helgaas

PCI: Mark invalid BARs as unassigned

2015-03-12T23:52:12+00:00

If a BAR is not inside any upstream bridge window, or if it conflicts with
another resource, mark it as IORESOURCE_UNSET so we don't try to use it.
We may be able to assign a different address for it.

Signed-off-by: Bjorn Helgaas 
Acked-by: Rafael J. Wysocki

PCI: Tidy resource assignment messages

2014-07-08T22:29:08+00:00

Print messages about failures in pci_assign_resource().  We can drop the
"by-hand" message from _pci_assign_resource() because %pR now prints the
size rather than the address if the resource hasn't been assigned.

No functional change.

Signed-off-by: Bjorn Helgaas

PCI: Return conventional error values from pci_revert_fw_address()

2014-07-08T22:29:08+00:00

Previously we returned zero for success or 1 for failure.  This changes
that so we return zero for success or a negative errno for failure.

No functional change.

Signed-off-by: Bjorn Helgaas

PCI: Cleanup control flow

2014-07-08T22:29:08+00:00

Return errors immediately so the straightline path is the normal,
no-error path.  No functional change.

Signed-off-by: Bjorn Helgaas

PCI: Keep original resource if we fail to expand it

2014-07-04T00:30:29+00:00

If we have space assigned to a resource, we try to expand the resource
(e.g., to accommodate SR-IOV resources), and the expansion attempt fails,
we should keep the original assignment.

After bd064f0a231a ("PCI: Mark resources as IORESOURCE_UNSET if we can't
assign them"), we left the resource marked IORESOURCE_UNSET when the
expansion failed, even if it had originally been set.  That caused errors
like this:

  pci 0003:00:00.0: can't enable device: BAR 15 [mem size 0x0c000000 64bit pref] not assigned
  pci 0003:00:00.0: Error enabling bridge (-22), continuing

Fix this by restoring the original flags when reassignment fails.

[bhelgaas: reworked to simplify, changelog]
Fixes: bd064f0a231a ("PCI: Mark resources as IORESOURCE_UNSET if we can't assign them")
Signed-off-by: Guo Chao 
Signed-off-by: Bjorn Helgaas 
CC: stable@vger.kernel.org	# v3.15+