Commit Graph

3459 Commits

Author SHA1 Message Date
Bjorn Helgaas
e5028b52e4 Merge branch 'topic/jiang-mmconfig-v10' into next
* topic/jiang-mmconfig-v10:
  ACPI: mark acpi_sfi_table_parse() as __init
  x86/PCI: use pr_level() to replace printk(KERN_LEVEL)
  x86/PCI: refine __pci_mmcfg_init() for better code readability
  x86/PCI: get rid of redundant log messages
  x86/PCI: simplify pci_mmcfg_late_insert_resources()
  x86/PCI: update MMCONFIG information when hot-plugging PCI host bridges
  PCI/ACPI: provide MMCONFIG address for PCI host bridges
  x86/PCI: add pci_mmconfig_insert()/delete() for PCI root bridge hotplug
  x86/PCI: prepare pci_mmcfg_check_reserved() to be called at runtime
  x86/PCI: introduce pci_mmcfg_arch_map()/pci_mmcfg_arch_unmap()
  x86/PCI: use RCU list to protect mmconfig list
  x86/PCI: split out pci_mmconfig_alloc() for code reuse
  x86/PCI: split out pci_mmcfg_check_reserved() for code reuse
2012-06-22 15:39:00 -06:00
Bjorn Helgaas
0f6662a49b Merge branch 'topic/bjorn-trivial' into next
* topic/bjorn-trivial:
  PCI: remove useless pcix_set_mmrbc() dev->bus check
  PCI: acpiphp: check whether _ADR evaluation succeeded
  PCI: shpchp: remove dead code
  PCI: fix P2P bridge I/O port window sign extension
  PCI: fix upstream P2P bridge checks when enabling OBFF and LTR
  PCI: use __weak consistently
  PCI: cleanup assign_requested_resources_sorted() kernel-doc warning
  sparc/PCI: remove unused pcibios_assign_resource() definition
2012-06-22 15:32:50 -06:00
Jiang Liu
f4b57a3b43 PCI/ACPI: provide MMCONFIG address for PCI host bridges
This patch provide MMCONFIG address for PCI host bridges, which will
be used to support host bridge hotplug.  It gets MMCONFIG address
by evaluating _CBA method if available.

Reviewed-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-22 15:16:51 -06:00
Bjorn Helgaas
809a3bf9f3 PCI: remove useless pcix_set_mmrbc() dev->bus check
For a valid pci_dev, dev->bus != NULL always, so remove this
unnecessary test.

Found by Coverity (CID 101680).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-20 17:28:53 -06:00
Bjorn Helgaas
dfb117b3e5 PCI: acpiphp: check whether _ADR evaluation succeeded
Check whether we evaluated _ADR successfully.  Previously we ignored
failure, so we would have used garbage data from the stack as the device
and function number.

We return AE_OK so that we ignore only this slot and continue looking
for other slots.

Found by Coverity (CID 113981).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-20 17:28:53 -06:00
Bjorn Helgaas
67454b6602 PCI: shpchp: remove dead code
"slots_not_empty" is initialized to zero and can't be set again before
reaching this point, so this return statement is dead.  Remove it.

Found by Coverity (CID 114324).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-20 17:28:53 -06:00
Bjorn Helgaas
8f38eaca55 PCI: fix P2P bridge I/O port window sign extension
On P2P bridges with 32-bit I/O decoding, we incorrectly sign-extended
windows starting at 0x80000000 or above.  In "base |= (io_base_hi << 16)",
"io_base_hi" is promoted to a signed int before being extended to an
unsigned long.

This would cause a window starting at I/O address 0x80000000 to be
treated as though it started at 0xffffffff80008000 instead, which
should cause "no compatible bridge window" errors when we enumerate
devices using that I/O space.

The mmio and mmio_pref casts are not strictly necessary, but without
them, correctness depends on the types of the PCI_MEMORY_RANGE_MASK and
PCI_PREF_RANGE_MASK constants, which are not obvious from reading the
local code.

Found by Coverity (CID 138747 and CID 138748).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-20 17:28:53 -06:00
Bjorn Helgaas
8291550f84 PCI: fix upstream P2P bridge checks when enabling OBFF and LTR
pci_enable_obff() and pci_enable_ltr() incorrectly check "dev->bus" instead
of "dev->bus->self" to determine whether the upstream device is a P2P
bridge or a host bridge.  For devices on the root bus, the upstream device
is a host bridge, "dev->bus != NULL" and "dev->bus->self == NULL", and we
panic with a null pointer dereference.

These functions should previously have panicked when called on devices
supporting OBFF or LTR, so they should be regarded as untested.

Found by Coverity (CID 143038 and CID 143039).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-20 17:28:53 -06:00
Bjorn Helgaas
d6d88c832e PCI: use __weak consistently
Use "__weak" instead of the gcc-specific "__attribute__ ((weak))"

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-20 10:44:35 -06:00
Wanpeng Li
8356aad430 PCI: cleanup assign_requested_resources_sorted() kernel-doc warning
Warning(drivers/pci/setup-bus.c:277): No description found for parameter 'fail_head'
Warning(drivers/pci/setup-bus.c:277): Excess function parameter 'failed_list' description in 'assign_requested_resources_sorted'

Signed-off-by: Wanpeng Li <liwp.linux@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-20 10:44:35 -06:00
Bjorn Helgaas
140217ae3f Merge branch 'topic/jan-intx-masking' into next
* topic/jan-intx-masking:
  PCI: add Ralink RT2800 broken INTx masking quirk
  PCI: add Chelsio T310 10GbE NIC broken INTx masking quirk
  PCI: add infrastructure for devices with broken INTx masking
2012-06-18 12:14:16 -06:00
Bjorn Helgaas
e822a00704 Merge branch 'topic/sebastian-devinit-fixups' into next
* topic/sebastian-devinit-fixups:
  scripts/modpost: check for bad references in .pci.fixups area
  sh/PCI: move fixup hooks from __init to __devinit
  powerpc/PCI: move fixup hooks from __init to __devinit
  frv/PCI: move fixup hooks from __init to __devinit
  arm/PCI: move fixup hooks from __init to __devinit
  alpha/PCI: move fixup hooks from __init to __devinit
  PCI: move fixup hooks from __init to __devinit
  x86/PCI: move fixup hooks from __init to __devinit
2012-06-18 12:14:10 -06:00
Bjorn Helgaas
47fcb6da65 Merge branch 'topic/stowe-cap-cleanup' into next
* topic/stowe-cap-cleanup:
  PCI: remove redundant capabilities checking in pci_{save, restore}_pcie_state
  PCI: add pci_pcie_cap2() check for PCIe feature capabilities >= v2
  PCI: remove redundant checking in PCI Express capability routines
  PCI: make pci_ltr_supported() static
2012-06-18 12:10:39 -06:00
Alex Williamson
0bdb3b213a PCI: add Ralink RT2800 broken INTx masking quirk
Passes pci_intx_mask_supported test but continues to send interrupts
as discovered through VFIO-based device assignment.

http://www.spinics.net/lists/kvm/msg73738.html

[bhelgaas: use HEADER, not FINAL, which is currently broken for hotplug]
Tested-by: Andreas Hartmann <andihartmann@01019freenet.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-18 11:51:22 -06:00
Jan Kiszka
de509f9f08 PCI: add Chelsio T310 10GbE NIC broken INTx masking quirk
According to

http://thread.gmane.org/gmane.comp.emulators.kvm.devel/91388

the T310 does not properly support INTx masking as it fails to keep the
PCI_STATUS_INTERRUPT bit updated once the interrupt is masked. Mark this
adapter as broken so that pci_intx_mask_supported won't report it as
compatible.

[bhelgaas: use HEADER, not FINAL, which is currently broken for hotplug]
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-18 11:48:13 -06:00
Bjorn Helgaas
fbebb9fd22 PCI: add infrastructure for devices with broken INTx masking
pci_intx_mask_supported() assumes INTx masking is supported if the
PCI_COMMAND_INTX_DISABLE bit is writable.  But when that bit is set,
some devices don't actually mask INTx or update PCI_STATUS_INTERRUPT
as we expect.

This patch adds a way for quirks to identify these broken devices.

[bhelgaas: split out from Chelsio quirk addition]
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-16 14:40:22 -06:00
Bjorn Helgaas
cc2fa3fa32 Merge branch 'topic/alex-vfio-prep' into next
* topic/alex-vfio-prep:
  PCI: misc pci_reg additions
  PCI: create common pcibios_err_to_errno
  PCI: export pci_user functions for use by other drivers
  PCI: add ACS validation utility
  PCI: add PCI DMA source ID quirk
2012-06-13 17:04:54 -06:00
Bjorn Helgaas
10c480933d Merge branch 'topic/bjorn-remove-unused' into next
* topic/bjorn-remove-unused:
  PCI/AER: use pci_is_pcie() instead of obsolete pci_dev.is_pcie
  PCI: remove pci_max_busnr() (was already commented out)
  PCI: remove pci_bus_find_ext_capability() (unused)
2012-06-13 17:04:51 -06:00
Amos Kong
ce29ca3ea4 PCI: acpiphp: remove all functions in slot, even without ACPI _EJx
When we add a device with acpiphp, we enumerate all functions in the
slot with pci_scan_slot(), regardless of whether they have associated
ACPI methods such as _EJ0.

When removing the device, we previously removed only the functions
with those ACPI methods.  This patch makes the remove symmetric with the
add: we remove all functions in the slot, whether they have associated
ACPI methods or not.

With qemu-kvm and SeaBIOS, we can build a multi-function device where
only function 0 has _EJ0 and _ADR (see bugzilla below).  Removing and
re-adding that slot (including all functions of the device) works correctly
with Windows guests.  This patch makes it also work in Linux guests.

[bhelgaas: restructure loop iteration, pull out of slot->funcs loop]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=43219
Signed-off-by: Amos Kong <kongjianjun@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 16:38:10 -06:00
Amos Kong
638f293307 PCI: acpiphp: fix function 0 leak when disabling a slot
Previously, we acquired two references to function 0, but only released
one.

[bhelgaas: split this out from "remove all functions" fix]
Signed-off-by: Amos Kong <kongjianjun@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 16:38:06 -06:00
Yinghai Lu
06aef8cec7 PCI: hotplug: remove pci_do_scan_bus()
All callers of pci_do_scan_bus() are gone, so remove it.

Note that pci_do_scan_bus() was exported, so out-of-tree modules could
depend on it.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:27 -06:00
Yinghai Lu
69ba29b9f9 PCI: sgihp: use generic pci_hp_add_bridge()
Use the new generic pci_hp_add_bridge() interface.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:27 -06:00
Yinghai Lu
2d7abf3292 PCI: ibmhp: use generic pci_hp_add_bridge()
Use the new generic pci_hp_add_bridge() interface.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:26 -06:00
Yinghai Lu
04de975e78 PCI: cpqhp: use generic pci_hp_add_bridge()
Use the new generic pci_hp_add_bridge() interface.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:26 -06:00
Yinghai Lu
7d01f70ac6 PCI: shpchp: use generic pci_hp_add_bridge()
Use the new generic pci_hp_add_bridge() interface.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:26 -06:00
Yinghai Lu
073ae10c0f PCI: cpci_hotplug: use generic pci_hp_add_bridge()
Use the new generic pci_hp_add_bridge() interface.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:26 -06:00
Yinghai Lu
c6da81a4d3 PCI: pciehp: use generic pci_hp_add_bridge()
Use the new generic pci_hp_add_bridge() interface.

[bhelgaas: split "add generic pci_hp_add_bridge()" into a separate patch]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:26 -06:00
Yinghai Lu
a8e4b9c101 PCI: add generic pci_hp_add_bridge()
This creates a generic pci_hp_add_bridge() that can be used by several
hotplug drivers.

[bhelgaas: split out from pciehp patch]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:26 -06:00
Yinghai Lu
85019faf4a PCI: sgihp: register busn_res
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:26 -06:00
Yinghai Lu
d0a350fe57 PCI: ibmhp: register busn_res
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:25 -06:00
Yinghai Lu
450878759a PCI: cpqhp: register busn_res
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:25 -06:00
Yinghai Lu
6cda0fcf26 PCI: shpchp: register busn_res
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:25 -06:00
Yinghai Lu
f406384628 PCI: cpci_hotplug: register busn_res
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:25 -06:00
Yinghai Lu
bc76b7310a PCI: insert busn_res for child bus
Now we can insert busn_res now, after all root bus's get inserted.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:25 -06:00
Yinghai Lu
b7eac055c0 PCI: register busn_res for iov bus
Insert that to tree.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:25 -06:00
Yinghai Lu
857c3b668a PCI: add default busn_res for pci_scan_bus()
also do not need to shrink busn_res.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:23 -06:00
Yinghai Lu
67cdc82728 PCI: add default busn_resource
We need to put into the resources list for legacy system.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:23 -06:00
Yinghai Lu
4d99f52423 PCI: checking busn_res in pci_scan_root_bus()
Some callers do not supply the bus number aperture, usually because they do
not know the end.  In this case, we assume the aperture extends from the
root bus number to bus 255, scan the bus, and shrink the bus number
resource so it ends at the largest bus number we found.

This is obviously not correct because the actual end of the aperture may
well be larger than the largest bus number we found.  But I guess it's all
we have for now.

Also print out one info about that, so we could find out which path
does not have busn_res in resources list.

[bhelgaas: changelog, _safe iterator unnecessary, use %pR format for bus]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
2012-06-13 15:42:23 -06:00
Yinghai Lu
f848ffb104 PCI: insert busn_res in pci_create_root_bus()
That busn_res is from resources list.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:22 -06:00
Yinghai Lu
f6dd68a77f PCI: release busn_res when removing bus
Release bus number resource when removing a bus.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:22 -06:00
Yinghai Lu
98a3583107 PCI: add busn_res operation functions
Will use them insert/update busn res in pci_bus struct.

[bhelgaas: print conflicting entry if insertion fails]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:22 -06:00
Yinghai Lu
5cc62c2022 PCI: build a bus number resource tree for every domain
This adds get_pci_domain_busn_res(), which returns the root of the
bus number resource tree for a domain, creating it if necessary.
We will later populate the tree with the bus numbers used by host
bridges and P2P bridges in the domain.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:22 -06:00
Yinghai Lu
b918c62e08 PCI: replace struct pci_bus secondary/subordinate with busn_res
Replace the struct pci_bus secondary/subordinate members with the
struct resource busn_res.  Later we'll build a resource tree of these
bus numbers.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-13 15:42:22 -06:00
Alan Stern
c2fb8a3fa2 USB: add NO_D3_DURING_SLEEP flag and revert 151b612847
This patch (as1558) fixes a problem affecting several ASUS computers:
The machine crashes or corrupts memory when going into suspend if the
ehci-hcd driver is bound to any controllers.  Users have been forced
to unbind or unload ehci-hcd before putting their systems to sleep.

After extensive testing, it was determined that the machines don't
like going into suspend when any EHCI controllers are in the PCI D3
power state.  Presumably this is a firmware bug, but there's nothing
we can do about it except to avoid putting the controllers in D3
during system sleep.

The patch adds a new flag to indicate whether the problem is present,
and avoids changing the controller's power state if the flag is set.
Runtime suspend is unaffected; this matters only for system suspend.
However as a side effect, the controller will not respond to remote
wakeup requests while the system is asleep.  Hence USB wakeup is not
functional -- but of course, this is already true in the current state
of affairs.

A similar patch has already been applied as commit
151b612847 (USB: EHCI: fix crash during
suspend on ASUS computers).  The patch supersedes that one and reverts
it.  There are two differences:

	The old patch added the flag at the USB level; this patch
	adds it at the PCI level.

	The old patch applied to all chipsets with the same vendor,
	subsystem vendor, and product IDs; this patch makes an
	exception for a known-good system (based on DMI information).

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Dâniel Fraga <fragabr@gmail.com>
Tested-by: Andrey Rahmatullin <wrar@wrar.name>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 13:11:39 -07:00
Alex Williamson
c63587d7f5 PCI: export pci_user functions for use by other drivers
VFIO PCI support will make use of these for user-initiated
PCI config accesses.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-12 09:21:42 -06:00
Alex Williamson
ad805758c0 PCI: add ACS validation utility
In a PCI environment, transactions aren't always required to reach
the root bus before being re-routed.  Intermediate switches between
an endpoint and the root bus can redirect DMA back downstream before
things like IOMMUs have a chance to intervene.  Legacy PCI is always
susceptible to this as it operates on a shared bus.  PCIe added a
new capability to describe and control this behavior, Access Control
Services, or ACS.

The utility function pci_acs_enabled() allows us to test the ACS
capabilities of an individual devices against a set of flags while
pci_acs_path_enabled() tests a complete path from a given downstream
device up to the specified upstream device.  We also include the
ability to add device specific tests as it's likely we'll see
devices that do not implement ACS, but want to indicate support
for various capabilities in this space.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-12 09:21:42 -06:00
Sebastian Andrzej Siewior
b99ea85a3a PCI: move fixup hooks from __init to __devinit
The fixups are executed once the pci-device is found which is during
boot process so __init seems fine as long as the platform does not
support hotplug.

However it is possible to remove the PCI bus at run time and have it
rediscovered again via "echo 1 > /sys/bus/pci/rescan" and this will call
the fixups again.

Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-12 09:10:54 -06:00
Myron Stowe
9cb604ed45 PCI: remove redundant capabilities checking in pci_{save, restore}_pcie_state
Unlike PCI Express v1's Capabilities Structure, v2's requires the entire
structure to be implemented.  In v2 structures, register fields that
are not implemented are present but hardwired to 0x0.  These may
include: Link Capabilities, Status, and Control; Slot Capabilities,
Status, and Control; Root Capabilities, Status, and Control; and all of
the '2' (Device, Link, and Slot) Capabilities, Status, and Control
registers.

This patch removes the redundant capability checks corresponding to the
Link 2's and Slot 2's, Capabilities, Status, and Control registers as they
will be present if Device Capabilities 2's registers are (which explains
why the macros for each of the three are identical).

Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-11 20:41:28 -06:00
Myron Stowe
c463b8cb93 PCI: add pci_pcie_cap2() check for PCIe feature capabilities >= v2
This patch resolves potential issues when accessing PCI Express
Capability structures.  The makeup of the capability varies
substantially between v1 and v2:

    Version 1 of the PCI Express Capability (defined by PCI Express
    1.0 and 1.1 base) neither requires the endpoint to implement the
    entire PCIe capability structure nor specifies default values of
    registers that are not implemented by the device.

    Version 2 of the PCI Express Capability (defined by PCIe 1.1
    Capability Structure Expansion ECN, PCIe 2.0, 2.1, and 3.0) added
    additional registers to the structure and requires all registers
    to be either implemented or hardwired to 0.

Due to the differences in the capability structures, code dealing with
capability features must be careful not to access the additional
registers introduced with v2 unless the device is specifically known to
be a v2 capable device.  Otherwise, attempts to access non-existant
registers will occur.  This is a subtle issue that is hard to track down
when it occurs (and it has - see commit 864d296cf9).

To try and help mitigate such occurrences, this patch introduces
pci_pcie_cap2() which is similar to pci_pcie_cap() but also checks
that the PCIe capability version is >= 2.  pci_pcie_cap2() should be
used for qualifying PCIe capability features introduced after v1.

Suggested by Don Dutile.

Acked-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-11 20:41:23 -06:00
Myron Stowe
cb97ae3485 PCI: remove redundant checking in PCI Express capability routines
There are a number of redundant pci_is_pcie() checks in various PCI
Express capabilities related routines like the following:

    if (!pci_is_pcie(dev))
	return false;

    pos = pci_pcie_cap(dev);
    if (!pos)
	return false;

The current pci_is_pcie() implementation is merely:

    static inline bool pci_is_pcie(struct pci_dev *dev)
    {
        return !!pci_pcie_cap(dev);
    }

so we can just drop the pci_is_pcie() test in such cases.

Acked-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-11 20:40:57 -06:00