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  1. 11 9月, 2014 1 次提交
    • B
      PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device · b440bde7
      由 Bjorn Helgaas 提交于 
      Powering off a hot-pluggable device, e.g., with pci_set_power_state(D3cold),
normally generates a hot-remove event that unbinds the driver.

Some drivers expect to remain bound to a device even while they power it
off and back on again.  This can be dangerous, because if the device is
removed or replaced while it is powered off, the driver doesn't know that
anything changed.  But some drivers accept that risk.

Add pci_ignore_hotplug() for use by drivers that know their device cannot
be removed.  Using pci_ignore_hotplug() tells the PCI core that hot-plug
events for the device should be ignored.

The radeon and nouveau drivers use this to switch between a low-power,
integrated GPU and a higher-power, higher-performance discrete GPU.  They
power off the unused GPU, but they want to remain bound to it.

This is a reimplementation of f244d8b6 ("ACPIPHP / radeon / nouveau:
Fix VGA switcheroo problem related to hotplug") but extends it to work with
both acpiphp and pciehp.

This fixes a problem where systems with dual GPUs using the radeon drivers
become unusable, freezing every few seconds (see bugzillas below).  The
resume of the radeon device may also fail, e.g.,

This fixes problems on dual GPU systems where the radeon driver becomes
unusable because of problems while suspending the device, as in bug 79701:

    [drm] radeon: finishing device.
    radeon 0000:01:00.0: Userspace still has active objects !
    radeon 0000:01:00.0: ffff8800cb4ec288 ffff8800cb4ec000 16384 4294967297 force free
    ...
    WARNING: CPU: 0 PID: 67 at /home/apw/COD/linux/drivers/gpu/drm/radeon/radeon_gart.c:234 radeon_gart_unbind+0xd2/0xe0 [radeon]()
    trying to unbind memory from uninitialized GART !

or while resuming it, as in bug 77261:

    radeon 0000:01:00.0: ring 0 stalled for more than 10158msec
    radeon 0000:01:00.0: GPU lockup ...
    radeon 0000:01:00.0: GPU pci config reset
    pciehp 0000:00:01.0:pcie04: Card not present on Slot(1-1)
    radeon 0000:01:00.0: GPU reset succeeded, trying to resume
    *ERROR* radeon: dpm resume failed
    radeon 0000:01:00.0: Wait for MC idle timedout !

Link: https://bugzilla.kernel.org/show_bug.cgi?id=77261
Link: https://bugzilla.kernel.org/show_bug.cgi?id=79701Reported-by: NShawn Starr <shawn.starr@rogers.com>
Reported-by: NJose P. <lbdkmjdf@sharklasers.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NRajat Jain <rajatxjain@gmail.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NDave Airlie <airlied@redhat.com>
CC: stable@vger.kernel.org	# v3.15+
      b440bde7
  3. 17 7月, 2014 1 次提交
  5. 04 7月, 2014 1 次提交
  7. 20 6月, 2014 1 次提交
  9. 30 5月, 2014 1 次提交
  11. 29 5月, 2014 5 次提交
    • A
      PCI: Introduce new device binding path using pci_dev.driver_override · 782a985d
      由 Alex Williamson 提交于 
      The driver_override field allows us to specify the driver for a device
rather than relying on the driver to provide a positive match of the
device.  This shortcuts the existing process of looking up the vendor and
device ID, adding them to the driver new_id, binding the device, then
removing the ID, but it also provides a couple advantages.

First, the above existing process allows the driver to bind to any device
matching the new_id for the window where it's enabled.  This is often not
desired, such as the case of trying to bind a single device to a meta
driver like pci-stub or vfio-pci.  Using driver_override we can do this
deterministically using:

  echo pci-stub > /sys/bus/pci/devices/0000:03:00.0/driver_override
  echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind
  echo 0000:03:00.0 > /sys/bus/pci/drivers_probe

Previously we could not invoke drivers_probe after adding a device to
new_id for a driver as we get non-deterministic behavior whether the driver
we intend or the standard driver will claim the device.  Now it becomes a
deterministic process, only the driver matching driver_override will probe
the device.

To return the device to the standard driver, we simply clear the
driver_override and reprobe the device:

  echo > /sys/bus/pci/devices/0000:03:00.0/driver_override
  echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind
  echo 0000:03:00.0 > /sys/bus/pci/drivers_probe

Another advantage to this approach is that we can specify a driver override
to force a specific binding or prevent any binding.  For instance when an
IOMMU group is exposed to userspace through VFIO we require that all
devices within that group are owned by VFIO.  However, devices can be
hot-added into an IOMMU group, in which case we want to prevent the device
from binding to any driver (override driver = "none") or perhaps have it
automatically bind to vfio-pci.  With driver_override it's a simple matter
for this field to be set internally when the device is first discovered to
prevent driver matches.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: NAlexander Graf <agraf@suse.de>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      782a985d
    • A
      PCI: Add support for PCIe-to-PCI bridge DMA alias quirks · c8fe16e3
      由 Alex Williamson 提交于 
      Several PCIe-to-PCI bridges fail to provide a PCIe capability, causing us
to handle them as conventional PCI devices when they really use the
requester ID of the secondary bus.  We need to differentiate these from
PCIe-to-PCI bridges that actually use the conventional PCI ID when a PCIe
capability is not present, such as those found on the root complex of may
Intel chipsets.  Add a dev_flag bit to identify devices to be handled as
standard PCIe-to-PCI bridges.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      c8fe16e3
    • A
      PCI: Add support for DMA alias quirks · 31c2b815
      由 Alex Williamson 提交于 
      Some devices are broken and use a requester ID other than their physical
devfn.  Add a byte, using an existing gap in the pci_dev structure, to
store an alternate "alias" devfn.  A bit in the dev_flags tells us when
this is valid.  We then add the alias as one more step in the
pci_for_each_dma_alias() iterator.
Tested-by: NGeorge Spelvin <linux@horizon.com>
Tested-by: NPat Erley <pat-lkml@erley.org>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      31c2b815
    • A
      PCI: Convert pci_dev_flags definitions to bit shifts · 6b121592
      由 Alex Williamson 提交于 
      Convert the pci_dev_flags definitions from decimal constants to bit shifts.
We're only a few entries away from where using the decimal value becomes
cumbersome.  No functional change.
Tested-by: NGeorge Spelvin <linux@horizon.com>
Tested-by: NPat Erley <pat-lkml@erley.org>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      6b121592
    • A
      PCI: Add DMA alias iterator · c25dc828
      由 Alex Williamson 提交于 
      In a mixed PCI/PCI-X/PCIe topology, bridges can take ownership of
transactions, replacing the original requester ID with their own.
Sometimes we just want to know the resulting device or resulting alias;
other times we want each step in the chain.  This iterator allows either
usage.  When an endpoint is connected via an unbroken chain of PCIe
switches and root ports, it has no alias and its requester ID is visible to
the root bus.  When PCI/X get in the way, we pick up aliases for bridges.

The reason why we potentially care about each step in the path is because
of PCI-X.  PCI-X has the concept of a requester ID, but bridges may or may
not take ownership of various types of transactions.  We therefore leave it
to the consumer of this function to prune out what they don't care about
rather than attempt to flatten the alias ourselves.
Tested-by: NGeorge Spelvin <linux@horizon.com>
Tested-by: NPat Erley <pat-lkml@erley.org>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      c25dc828
  13. 28 5月, 2014 4 次提交
  15. 23 5月, 2014 1 次提交
  17. 01 5月, 2014 1 次提交
    • A
      PCI/MSI: Remove pci_enable_msi_block() · 034cd97e
      由 Alexander Gordeev 提交于 
      There are no users of pci_enable_msi_block() function left.  Obsolete it in
favor of pci_enable_msi_range() and pci_enable_msi_exact() functions.

Previously, we called arch_setup_msi_irqs() once, requesting the same
vector count we passed to arch_msi_check_device().  Now we may call it
several times: if it returns failure, we may retry and request fewer
vectors.

We don't keep track of the vector count we initially passed to
arch_msi_check_device().  We only keep track of the number of vectors
successfully set up by arch_setup_msi_irqs(), and this is what we use to
clean things up when disabling MSI.  Therefore, we assume that
arch_msi_check_device() does nothing that will have to be cleaned up later.

[bhelgaas: changelog]
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      034cd97e
  19. 25 4月, 2014 1 次提交
  21. 20 3月, 2014 1 次提交
  23. 20 2月, 2014 1 次提交
  25. 15 2月, 2014 1 次提交
  27. 14 2月, 2014 2 次提交
  29. 12 2月, 2014 2 次提交
  31. 15 1月, 2014 1 次提交
    • A
      PCI: Add pci_try_reset_function(), pci_try_reset_slot(), pci_try_reset_bus() · 61cf16d8
      由 Alex Williamson 提交于 
      When doing a function/slot/bus reset PCI grabs the device_lock for each
device to block things like suspend and driver probes, but call paths exist
where this lock may already be held.  This creates an opportunity for
deadlock.  For instance, vfio allows userspace to issue resets so long as
it owns the device(s).  If a driver unbind .remove callback races with
userspace issuing a reset, we have a deadlock as userspace gets stuck
waiting on device_lock while another thread has device_lock and waits for
.remove to complete.  To resolve this, we can make a version of the reset
interfaces which use trylock.  With this, we can safely attempt a reset and
return error to userspace if there is contention.

[bhelgaas: the deadlock happens when A (userspace) has a file descriptor for
the device, and B waits in this path:

  driver_detach
    device_lock                     # take device_lock
    __device_release_driver
      pci_device_remove             # pci_bus_type.remove
        vfio_pci_remove             # pci_driver .remove
          vfio_del_group_dev
            wait_event(vfio.release_q, !vfio_dev_present)   # wait (holding device_lock)

Now B is stuck until A gives up the file descriptor.  If A tries to acquire
device_lock for any reason, we deadlock because A is waiting for B to release
the lock, and B is waiting for A to release the file descriptor.]
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      61cf16d8
  33. 14 1月, 2014 8 次提交
  35. 11 1月, 2014 3 次提交
  37. 08 1月, 2014 1 次提交
    • Y
      PCI: Enforce bus address limits in resource allocation · f75b99d5
      由 Yinghai Lu 提交于 
      When allocating space for 32-bit BARs, we previously limited RESOURCE
addresses so they would fit in 32 bits.  However, the BUS address need not
be the same as the resource address, and it's the bus address that must fit
in the 32-bit BAR.

This patch adds:

  - pci_clip_resource_to_region(), which clips a resource so it contains
    only the range that maps to the specified bus address region, e.g., to
    clip a resource to 32-bit bus addresses, and

  - pci_bus_alloc_from_region(), which allocates space for a resource from
    the specified bus address region,

and changes pci_bus_alloc_resource() to allocate space for 64-bit BARs from
the entire bus address region, and space for 32-bit BARs from only the bus
address region below 4GB.

If we had this window:

  pci_root HWP0002:0a: host bridge window [mem 0xf0180000000-0xf01fedfffff] (bus address [0x80000000-0xfedfffff])

we previously could not put a 32-bit BAR there, because the CPU addresses
don't fit in 32 bits.  This patch fixes this, so we can use this space for
32-bit BARs.

It's also possible (though unlikely) to have resources with 32-bit CPU
addresses but bus addresses above 4GB.  In this case the previous code
would allocate space that a 32-bit BAR could not map.

Remove PCIBIOS_MAX_MEM_32, which is no longer used.

[bhelgaas: reworked starting from http://lkml.kernel.org/r/1386658484-15774-3-git-send-email-yinghai@kernel.org]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      f75b99d5
  39. 04 1月, 2014 3 次提交
    • A
      PCI/MSI: Add pci_enable_msi_range() and pci_enable_msix_range() · 302a2523
      由 Alexander Gordeev 提交于 
      This adds pci_enable_msi_range(), which supersedes the pci_enable_msi()
and pci_enable_msi_block() MSI interfaces.

It also adds pci_enable_msix_range(), which supersedes the
pci_enable_msix() MSI-X interface.

The old interfaces have three categories of return values:

    negative: failure; caller should not retry
    positive: failure; value indicates number of interrupts that *could*
	have been allocated, and caller may retry with a smaller request
    zero: success; at least as many interrupts allocated as requested

It is error-prone to handle these three cases correctly in drivers.

The new functions return either a negative error code or a number of
successfully allocated MSI/MSI-X interrupts, which is expected to lead to
clearer device driver code.

pci_enable_msi(), pci_enable_msi_block() and pci_enable_msix() still exist
unchanged, but are deprecated and may be removed after callers are updated.

[bhelgaas: tweak changelog]
Suggested-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NTejun Heo <tj@kernel.org>
      302a2523
    • A
      PCI/MSI: Add pci_msix_vec_count() · ff1aa430
      由 Alexander Gordeev 提交于 
      This creates an MSI-X counterpart for pci_msi_vec_count().  Device drivers
can use this function to obtain maximum number of MSI-X interrupts the
device supports and use that number in a subsequent call to
pci_enable_msix().

pci_msix_vec_count() supersedes pci_msix_table_size() and returns a
negative errno if device does not support MSI-X interrupts.  After this
update, callers must always check the returned value.

The only user of pci_msix_table_size() was the PCI-Express port driver,
which is also updated by this change.
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NTejun Heo <tj@kernel.org>
      ff1aa430
    • A
      PCI/MSI: Remove pci_enable_msi_block_auto() · 7b92b4f6
      由 Alexander Gordeev 提交于 
      The new pci_msi_vec_count() interface makes pci_enable_msi_block_auto()
superfluous.

Drivers can use pci_msi_vec_count() to learn the maximum number of MSIs
supported by the device, and then call pci_enable_msi_block().

pci_enable_msi_block_auto() was introduced recently, and its only user is
the AHCI driver, which is also updated by this change.
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NTejun Heo <tj@kernel.org>
      7b92b4f6