PCI resets will attempt to take the device_lock for any device to be
reset.  This is a problem if that lock is already held, for instance
in the device remove path.  It's not sufficient to simply kill the
user process or skip the reset if called after .remove as a race could
result in the same deadlock.  Instead, we handle all resets as "best
effort" using the PCI "try" reset interfaces.  This prevents the user
from being able to induce a deadlock by triggering a reset.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

* pci/ifndefs:
  PCI: Cleanup pci.h whitespace
  PCI: Reorder so actual code comes before stubs

Put empty or trivial inline stub functions on one line when they fit.  No
functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Consistently use the:

    #ifdef CONFIG_PCI_FOO
    int pci_foo(...);
    #else
    static inline int pci_foo(...) { return -1; }
    #endif

pattern, instead of sometimes using "#ifndef CONFIG_PCI_FOO".

No functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

* pci/dead-code:
  PCI: Make local functions static
  PCI: Remove unused alloc_pci_dev()
  PCI: Remove unused pci_renumber_slot()
  PCI: Remove unused pcie_aspm_enabled()
  PCI: Remove unused pci_vpd_truncate()
  PCI: Remove unused ID-Based Ordering support
  PCI: Remove unused Optimized Buffer Flush/Fill support
  PCI: Remove unused Latency Tolerance Reporting support
  PCI: Removed unused parts of Page Request Interface support

Conflicts:
	drivers/pci/pci.c
	include/linux/pci.h

* pci/aer:
  PCI/AER: Support ACPI HEST AER error sources for PCI domains other than 0
  ACPICA: Add helper macros to extract bus/segment numbers from HEST table.

In the discussion for this set of patches [link below], Bjorn Helgaas
pointed out that the ACPI HEST AER error sources do not have the PCIe
segment number associated with the bus.  I worked with the ACPI spec and
got this change to definition of the "Bus" field into the recently released
ACPI Spec 5.0a section 18.3.2.3-5:

  Identifies the PCI Bus and Segment of the device.  The Bus is encoded in
  bits 0-7.  For systems that expose multiple PCI segment groups, the
  segment number is encoded in bits 8-23 and bits 24-31 must be zero.  For
  systems that do not expose multiple PCI segment groups, bits 8-31 must be
  zero.  If the GLOBAL flag is specified, this field is ignored.

This patch makes use of the new definition in the only place in the kernel
that uses the acpi_hest_aer_common's bus field.

This depends on 36f36151 ("ACPICA: Add helper macros to extract
bus/segment numbers from HEST table.")

Link: http://lkml.kernel.org/r/1370542251-27387-1-git-send-email-betty.dall@hp.comSigned-off-by: Betty Dall <betty.dall@hp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

This change adds two macros to extract the encoded bus and segment
numbers from the HEST Bus field.
Signed-off-by: Betty Dall <betty.dall@hp.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Using 'make namespacecheck' identify code which should be declared static.
Checked for users in other driver/archs as well.  Compile tested only.

This stops exporting the following interfaces to modules:

    pci_target_state()
    pci_load_saved_state()

[bhelgaas: retained pci_find_next_ext_capability() and pci_cfg_space_size()]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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 removes this unused and deprecated interface:

    alloc_pci_dev()

[bhelgaas: split to separate patch]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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 part of f46753c5 ("PCI: introduce pci_slot") and
d25b7c8d ("PCI: rename pci_update_slot_number to pci_renumber_slot"),
removing this interface:

    pci_renumber_slot()

[bhelgaas: split to separate patch, add historical link from Alex]
Link: http://lkml.kernel.org/r/20081009043140.8678.44164.stgit@bob.kioSigned-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Chiang <achiang@canonical.com>

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 part of 3e1b1600 ("ACPI/PCI: PCIe ASPM _OSC support
capabilities called when root bridge added"), removing this interface:

    pcie_aspm_enabled()

[bhelgaas: split to separate patch]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Andrew Patterson <andrew.patterson@hp.com>

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 db567943 ("PCI: add interface to set visible size of
VPD"), removing this interface:

    pci_vpd_truncate()

[bhelgaas: split to separate patch, also remove prototype from pci.h]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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 b48d4425 ("PCI: add ID-based ordering enable/disable
support"), removing these interfaces:

    pci_enable_ido()
    pci_disable_ido()

[bhelgaas: split to separate patch, also remove prototypes from pci.h]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>

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 48a92a81 ("PCI: add OBFF enable/disable support"),
removing these interfaces:

    pci_enable_obff()
    pci_disable_obff()

[bhelgaas: split to separate patch, also remove prototypes from pci.h]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>

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 51c2e0a7 ("PCI: add latency tolerance reporting
enable/disable support"), removing these interfaces:

    pci_enable_ltr()
    pci_disable_ltr()
    pci_set_ltr()

[bhelgaas: split to separate patch, also remove prototypes from pci.h]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>

* pci/resource:
  PCI: Allocate 64-bit BARs above 4G when possible
  PCI: Enforce bus address limits in resource allocation
  PCI: Split out bridge window override of minimum allocation address
  agp/ati: Use PCI_COMMAND instead of hard-coded 4
  agp/intel: Use CPU physical address, not bus address, for ioremap()
  agp/intel: Use pci_bus_address() to get GTTADR bus address
  agp/intel: Use pci_bus_address() to get MMADR bus address
  agp/intel: Support 64-bit GMADR
  agp/intel: Rename gtt_bus_addr to gtt_phys_addr
  drm/i915: Rename gtt_bus_addr to gtt_phys_addr
  agp: Use pci_resource_start() to get CPU physical address for BAR
  agp: Support 64-bit APBASE
  PCI: Add pci_bus_address() to get bus address of a BAR
  PCI: Convert pcibios_resource_to_bus() to take a pci_bus, not a pci_dev
  PCI: Change pci_bus_region addresses to dma_addr_t

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 c320b976 ("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 <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Joerg Roedel <joro@8bytes.org>

* pci/msi:
  PCI/MSI: Add pci_enable_msi_range() and pci_enable_msix_range()
  PCI/MSI: Add pci_msix_vec_count()
  PCI/MSI: Remove pci_enable_msi_block_auto()
  PCI/MSI: Add pci_msi_vec_count()

* pci/misc:
  PCI: Update documentation 00-INDEX file
  PCI: Convert ioapic to be builtin only, not modular

* pci/host-mvebu:
  PCI: mvebu: Use max_t() instead of max(resource_size_t,)
  PCI: mvebu: Call pci_ioremap_io() at startup instead of dynamically

* pci/host-designware:
  PCI: designware: Fix indent code style

The PCI-DMA-mapping.txt moved to general docs and became DMA-API-HOWTO.txt
in 5e07c2c7 ("Documentation: rename PCI/PCI-DMA-mapping.txt to
DMA-API-HOWTO.txt").  Add new file about PCI Express I/O Virtualization.
Signed-off-by: Erik Ekman <erik@kryo.se>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Try to allocate space for 64-bit BARs above 4G first, to preserve the space
below 4G for 32-bit BARs.  If there's no space above 4G available, fall
back to allocating anywhere.

[bhelgaas: reworked starting from http://lkml.kernel.org/r/1387485843-17403-2-git-send-email-yinghai@kernel.org]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

pci_bus_alloc_resource() avoids allocating space below the "min" supplied
by the caller (usually PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM).  This is to
protect badly documented motherboard resources.  But if we're allocating
space inside an already-configured PCI-PCI bridge window, we ignore "min".

See 688d1918 ("pci: make bus resource start address override minimum IO
address").

This patch moves the check to make it more visible and simplify future
patches.  No functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

We're accessing the PCI_COMMAND register here, so use the appropriate
#define.  The bit we're writing (1 << 14) isn't defined by the PCI or PCIe
spec, so we don't have a name for it.

No functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

In i810_setup(), i830_setup(), and i9xx_setup(), we use the result of
pci_bus_address() as an argument to ioremap() and to compute gtt_phys_addr.
These should use pci_resource_start() instead because we want the CPU
physical address, not the bus address.

If there were an AGP device behind a host bridge that translated addresses,
e.g., a PNP0A08 device with _TRA != 0, this would fix a bug.  I'm not aware
of any of those, but they are possible.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Per the Intel 915G/915GV/... Chipset spec (document number 301467-005),
GTTADR is a standard PCI BAR.

The PCI core reads GTTADR at enumeration-time.  Use pci_bus_address()
instead of reading it again in the driver.  This works correctly for both
32-bit and 64-bit BARs.  The spec above only mentions 32-bit GTTADR, but we
should still use the standard interface.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Per the Intel 915G/915GV/... Chipset spec (document number 301467-005),
MMADR is a standard PCI BAR.

The PCI core reads MMADR at enumeration-time.  Use pci_bus_address()
instead of reading it again in the driver.  This works correctly for both
32-bit and 64-bit BARs.  The spec above only mentions 32-bit MMADR, but we
should still use the standard interface.

Also, stop clearing the low 19 bits of the bus address because it's invalid
to use addresses outside the region defined by the BAR.  The spec claims
MMADR is 512KB; if that's the case, those bits will be zero anyway.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Per the Intel 915G/915GV/... Chipset spec (document number 301467-005),
GMADR is a standard PCI BAR.

The PCI core reads GMADR at enumeration-time.  Use pci_bus_address()
instead of reading it again in the driver.  This works correctly for both
32-bit and 64-bit BARs.  The spec above only mentions 32-bit GMADR, but
Yinghai's patch (link below) indicates some devices have a 64-bit GMADR.

[bhelgaas: reworked starting from http://lkml.kernel.org/r/1385851238-21085-13-git-send-email-yinghai@kernel.org]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

The only use of gtt_bus_addr is as an argument to ioremap(), so it is a CPU
physical address, not a bus address.  Rename it to gtt_phys_addr to reflect
this.

No functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

We're dealing with CPU physical addresses here, which may be different from
bus addresses, so rename gtt_bus_addr to gtt_phys_addr to avoid confusion.

No functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

amd_irongate_configure(), ati_configure(), and nvidia_configure() call
ioremap() on an address read directly from a BAR.  But a BAR contains a
bus address, and ioremap() expects a CPU physical address.  Use
pci_resource_start() to obtain the physical address.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Per the AGP 3.0 spec, APBASE is a standard PCI BAR and may be either 32
bits or 64 bits wide.  Many drivers read APBASE directly, but they only
handled 32-bit BARs.

The PCI core reads APBASE at enumeration-time.  Use pci_bus_address()
instead of reading it again in the driver.  This works correctly for both
32-bit and 64-bit BARs.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tejun Heo <tj@kernel.org>

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: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tejun Heo <tj@kernel.org>

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: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Tejun Heo <tj@kernel.org>

Device drivers can use this interface to obtain the maximum number of MSI
interrupts the device supports and use that number, e.g., in a subsequent
call to pci_enable_msi_block().
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tejun Heo <tj@kernel.org>