This patch fixes the following bug:
http://marc.info/?l=linux-usb&m=134318961120825&w=2
Originally, device lower power states include D1, D2, D3. After that,
D3 is further divided into D3hot and D3cold. To support both scenario
safely, original D3 is mapped to D3cold.
When adding D3cold support, because worry about some device may have
broken D3cold support, D3cold is disabled by default. This disable D3
on original platform too. But some original platform may only have
working D3, but no working D1, D2. The root cause of the above bug is
it too.
To deal with this, this patch enables D3/D3cold by default for most
devices. This restores the original behavior. For some devices that
suspected to have broken D3cold support, such as PCIe port, D3cold is
disabled by default.
Reported-by: Bjorn Mork <bjorn@mork.no>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
* pci/myron-pcibios_setup:
xtensa/PCI: factor out pcibios_setup()
x86/PCI: adjust section annotations for pcibios_setup()
unicore32/PCI: adjust section annotations for pcibios_setup()
tile/PCI: factor out pcibios_setup()
sparc/PCI: factor out pcibios_setup()
sh/PCI: adjust section annotations for pcibios_setup()
sh/PCI: factor out pcibios_setup()
powerpc/PCI: factor out pcibios_setup()
parisc/PCI: factor out pcibios_setup()
MIPS/PCI: adjust section annotations for pcibios_setup()
MIPS/PCI: factor out pcibios_setup()
microblaze/PCI: factor out pcibios_setup()
ia64/PCI: factor out pcibios_setup()
cris/PCI: factor out pcibios_setup()
alpha/PCI: factor out pcibios_setup()
PCI: pull pcibios_setup() up into core
Commit cc2893b6 (PCI: Ensure we re-enable devices on resume)
addressed the problem with USB not being powered after resume on
recent Lenovo machines, but it did that in a suboptimal way.
Namely, it should have changed the relevant code paths only,
which are pci_pm_resume_noirq() and pci_pm_restore_noirq() supposed
to restore the device's power and standard configuration registers
after system resume from suspend or hibernation. Instead, however,
it modified pci_set_power_state() which is executed in several
other situations too. That resulted in some undesirable effects,
like attempting to change a device's power state in the same way
multiple times in a row (up to as many as 4 times in a row in the
snd_hda_intel driver).
Fix the bug addressed by commit cc2893b6 in an alternative way,
by forcibly powering up all devices in pci_pm_default_resume_early(),
which is called by pci_pm_resume_noirq() and pci_pm_restore_noirq()
to restore the device's power and standard configuration registers,
and modifying pci_pm_runtime_resume() to avoid the forcible power-up
if not necessary. Then, revert the changes made by commit cc2893b6
to make the confusion introduced by it go away.
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Currently, all of the architectures implement their own pcibios_setup()
routine. Most of the implementations do nothing so this patch introduces
a generic (__weak) routine in the core that can be used by all
architectures as a default. If necessary, it can be overridden by
architecture-specific code.
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* topic/huang-d3cold-v7:
PCI/PM: add PCIe runtime D3cold support
PCI: do not call pci_set_power_state with PCI_D3cold
PCI/PM: add runtime PM support to PCIe port
ACPI/PM: specify lowest allowed state for device sleep state
This patch adds runtime D3cold support and corresponding ACPI platform
support. This patch only enables runtime D3cold support; it does not
enable D3cold support during system suspend/hibernate.
D3cold is the deepest power saving state for a PCIe device, where its main
power is removed. While it is in D3cold, you can't access the device at
all, not even its configuration space (which is still accessible in D3hot).
Therefore the PCI PM registers can not be used to transition into/out of
the D3cold state; that must be done by platform logic such as ACPI _PR3.
To support wakeup from D3cold, a system may provide auxiliary power, which
allows a device to request wakeup using a Beacon or the sideband WAKE#
signal. WAKE# is usually connected to platform logic such as ACPI GPE.
This is quite different from other power saving states, where devices
request wakeup via a PME message on the PCIe link.
Some devices, such as those in plug-in slots, have no direct platform
logic. For example, there is usually no ACPI _PR3 for them. D3cold
support for these devices can be done via the PCIe Downstream Port leading
to the device. When the PCIe port is powered on/off, the device is powered
on/off too. Wakeup events from the device will be notified to the
corresponding PCIe port.
For more information about PCIe D3cold and corresponding ACPI support,
please refer to:
- PCI Express Base Specification Revision 2.0
- Advanced Configuration and Power Interface Specification Revision 5.0
[bhelgaas: changelog]
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Originally-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This patch adds runtime PM support to PCIe port. This is needed by
PCIe D3cold support, where PCIe device without ACPI node may be
powered on/off by PCIe port.
Because runtime suspend is broken for some chipsets, a black list is
used to disable runtime PM support for these chipsets.
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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>
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>
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>
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>
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>
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>
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>
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>
The PCI Express Latency Tolerance Reporting (LTR) feature's
pci_ltr_supported() routine is currently only used within
drivers/pci/pci.c so make it static.
Acked-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
pci_max_busnr() has been commented out for years (since 54c762fe62), and
this patch removes it completely.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Pull MIPS updates from Ralf Baechle:
"The whole series has been sitting in -next for quite a while with no
complaints. The last change to the series was before the weekend the
removal of an SPI patch which Grant - even though previously acked by
himself - appeared to raise objections. So I removed it until the
situation is clarified. Other than that all the patches have the acks
from their respective maintainers, all MIPS and x86 defconfigs are
building fine and I'm not aware of any problems introduced by this
series.
Among the key features for this patch series is a sizable patchset for
Lantiq which among other things introduces support for Lantiq's
flagship product, the FALCON SOC. It also means that the opensource
developers behind this patchset have overtaken Lantiq's competing
inhouse development team that was working behind closed doors.
Less noteworthy the ath79 patchset which adds support for a few more
chip variants, cleanups and fixes. Finally the usual dose of tweaking
of generic code."
Fix up trivial conflicts in arch/mips/lantiq/xway/gpio_{ebu,stp}.c where
printk spelling fixes clashed with file move and eventual removal of the
printk.
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (81 commits)
MIPS: lantiq: remove orphaned code
MIPS: Remove all -Wall and almost all -Werror usage from arch/mips.
MIPS: lantiq: implement support for FALCON soc
MTD: MIPS: lantiq: verify that the NOR interface is available on falcon soc
MTD: MIPS: lantiq: implement OF support
watchdog: MIPS: lantiq: implement OF support and minor fixes
SERIAL: MIPS: lantiq: implement OF support
GPIO: MIPS: lantiq: convert gpio-stp-xway to OF
GPIO: MIPS: lantiq: convert gpio-mm-lantiq to OF and of_mm_gpio
GPIO: MIPS: lantiq: move gpio-stp and gpio-ebu to the subsystem folder
MIPS: pci: convert lantiq driver to OF
MIPS: lantiq: convert dma to platform driver
MIPS: lantiq: implement support for clkdev api
MIPS: lantiq: drop ltq_gpio_request() and gpio_to_irq()
OF: MIPS: lantiq: implement irq_domain support
OF: MIPS: lantiq: implement OF support
MIPS: lantiq: drop mips_machine support
OF: PCI: const usage needed by MIPS
MIPS: Cavium: Remove smp_reserve_lock.
MIPS: Move cache setup to setup_arch().
...
On MIPS we want to call of_irq_map_pci from inside
arch/mips/include/asm/pci.h:extern int pcibios_map_irq(
const struct pci_dev *dev, u8 slot, u8 pin);
For this to work we need to change several functions to const usage.
Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-pci@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Cc: linux-mips@linux-mips.org
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Patchwork: https://patchwork.linux-mips.org/patch/3710/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The intent of git commit 6fbf9e7a90
"PCI: Introduce __pci_reset_function_locked to be used when holding
device_lock." was to have a non-locking function that would call
pci_dev_reset function.
But it fell short of that by just probing and not actually reseting
the device. To make that work we need a way to move the lock
around device_lock to not be in pci_dev_reset (as the caller of
__pci_reset_function_locked already holds said lock). We do this by
renaming pci_dev_reset to __pci_dev_reset and bubbling said mutex out
of __pci_dev_reset to pci_dev_reset (a wrapper around __pci_dev_reset).
The __pci_reset_function_locked can now call __pci_dev_reset without
having to worry about the dead-lock.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
A PCIe downstream port is a P2P bridge. Its secondary interface is
a link that should lead only to device 0 (unless ARI is enabled)[1], so
we don't probe for non-zero device numbers.
Some Stratus ftServer systems have a PCIe downstream port (02:00.0) that
leads to both an upstream port (03:00.0) and a downstream port (03:01.0),
and 03:01.0 has important devices below it:
[0000:02]-+-00.0-[03-3c]--+-00.0-[04-09]--...
\-01.0-[0a-0d]--+-[USB]
+-[NIC]
+-...
Previously, we didn't enumerate device 03:01.0, so USB and the network
didn't work. This patch adds a DMI quirk to scan all device numbers,
not just 0, below a downstream port.
Based on a patch by Prarit Bhargava.
[1] PCIe spec r3.0, sec 7.3.1
CC: Myron Stowe <mstowe@redhat.com>
CC: Don Dutile <ddutile@redhat.com>
CC: James Paradis <james.paradis@stratus.com>
CC: Matthew Wilcox <matthew.r.wilcox@intel.com>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>
CC: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Some shortcomings introduced into pci_restore_state() by commit
26f41062f2 ("PCI: check for pci bar restore completion and retry")
have been fixed by recent commit ebfc5b802f ("PCI: Fix regression in
pci_restore_state(), v3"), but that commit treats all PCI devices as
those with Type 0 configuration headers.
That is not entirely correct, because Type 1 and Type 2 headers have
different layouts. In particular, the area occupied by BARs in Type 0
config headers contains the secondary status register in Type 1 ones and
it doesn't make sense to retry the restoration of that register even if
the value read back from it after a write is not the same as the written
one (it very well may be different).
For this reason, make pci_restore_state() only retry the restoration
of BARs for Type 0 config headers. This effectively makes it behave
as before commit 26f41062f2 for all header types except for Type 0.
Tested-by: Mikko Vinni <mmvinni@yahoo.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 26f41062f2 ("PCI: check for pci bar restore completion and
retry") attempted to address problems with PCI BAR restoration on
systems where FLR had not been completed before pci_restore_state() was
called, but it did that in an utterly wrong way.
First off, instead of retrying the writes for the BAR registers only, it
did that for all of the PCI config space of the device, including the
status register (whose value after the write quite obviously need not be
the same as the written one). Second, it added arbitrary delay to
pci_restore_state() even for systems where the PCI config space
restoration was successful at first attempt. Finally, the mdelay(10) it
added to every iteration of the writing loop was way too much of a delay
for any reasonable device.
All of this actually caused resume failures for some devices on Mikko's
system.
To fix the regression, make pci_restore_state() only retry the writes
for BAR registers and only wait if the first read from the register
doesn't return the written value. Additionaly, make it wait for 1 ms,
instead of 10 ms, after every failing attempt to write into config
space.
Reported-by: Mikko Vinni <mmvinni@yahoo.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are PCIe devices on the market that report ARI support but
then fail to initialize correctly when ARI is actually used. This
leads to situations in which kernels 2.6.34 and newer fail to handle
systems where the previous kernels worked without any apparent
problems. Unfortunately, it is currently unknown how many such
devices are there.
For this reason, introduce a new kernel command line option,
pci=noari, allowing users to disable PCIe ARI altogether if they
see problems with PCIe device initialization.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This isn't really a quirk; calling it directly from pci_add_device makes
more sense.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Let the user could enable and disable with pci=realloc=on or pci=realloc=off
Also
1. move variable and functions near the place they are used.
2. change macro to function
3. change related functions and variable to static and _init
4. update parameter description accordingly.
This will let us add a config option to control default behavior, and
still allow the user to turn off automatic reallocation if it fails on
their platform until a permanent solution is found.
-v2: still honor pci=realloc, and treat it as pci=realloc=on
also use enum instead of ...
-v3: update kernel-paramenters.txt according to Jesse.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Only one user in driver/pci/pci.c, so we don't need to put it in global
pci.h
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
On some OEM systems, pci_restore_state() is called while FLR has not yet
completed. As a result, PCI BAR register restore is not successful. This fix
reads back the restored value and compares it with saved value and re-tries 10
times before giving up.
Signed-off-by: Jean Guyader <jean.guyader@eu.citrix.com>
Signed-off-by: Eric Chanudet <eric.chanudet@citrix.com>
Signed-off-by: Allen Kay <allen.m.kay@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The use case of this is when a driver wants to call FLR when a device
is attached to it using the SysFS "bind" or "unbind" functionality.
The call chain when a user does "bind" looks as so:
echo "0000:01.07.0" > /sys/bus/pci/drivers/XXXX/bind
and ends up calling:
driver_bind:
device_lock(dev); <=== TAKES LOCK
XXXX_probe:
.. pci_enable_device()
...__pci_reset_function(), which calls
pci_dev_reset(dev, 0):
if (!0) {
device_lock(dev) <==== DEADLOCK
The __pci_reset_function_locked function allows the the drivers
'probe' function to call the "pci_reset_function" while still holding
the driver mutex lock.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Fix new kernel-doc warnings:
Warning(drivers/pci/pci.c:2811): No description found for parameter 'dev'
Warning(drivers/pci/pci.c:2811): Excess function parameter 'pdev' description in 'pci_intx_mask_supported'
Warning(drivers/pci/pci.c:2894): No description found for parameter 'dev'
Warning(drivers/pci/pci.c:2894): Excess function parameter 'pdev' description in 'pci_check_and_mask_intx'
Warning(drivers/pci/pci.c:2908): No description found for parameter 'dev'
Warning(drivers/pci/pci.c:2908): Excess function parameter 'pdev' description in 'pci_check_and_unmask_intx'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During S3 or S4 resume or PCI reset, ATS regs aren't restored correctly.
This patch enables ATS at the device state restore if PCI device has ATS
capability.
Signed-off-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
When the runtime PM is activated on PCI, if a device switches state
frequently (e.g. an EHCI controller with autosuspending USB devices
connected) the PCI configuration traces might be very verbose in the
kernel log. Let's guard those traces with DEBUG condition.
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The latency timer is read-only and hardwired to zero for all PCIe
devices, both Type 0 and Type 1, so don't bother trying to update it
and cluttering the dmesg log with meaningless "setting latency timer
to 64" messages.
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The 'latency timer' of PCI devices, both Type 0 and Type 1,
is setup in architecture-specific code [see: 'pcibios_set_master()'].
There are two approaches being taken by all the architectures - check
if the 'latency timer' is currently set between 16 and 255 and if not
bring it within bounds, or, do nothing (and then there is the
gratuitously different PA-RISC implementation).
There is nothing architecture-specific about PCI's 'latency timer' so
this patch pulls its setup functionality up into the PCI core by
creating a generic 'pcibios_set_master()' function using the '__weak'
attribute which can be used by all architectures as a default which,
if necessary, can then be over-ridden by architecture-specific code.
No functional change.
Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
These new PCI services allow to probe for 2.3-compliant INTx masking
support and then use the feature from PCI interrupt handlers. The
services are properly synchronized with concurrent config space access
via sysfs or on device reset.
This enables generic PCI device drivers like uio_pci_generic or KVM's
device assignment to implement the necessary kernel-side IRQ handling
without any knowledge about device-specific interrupt status and control
registers.
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
pci_block_user_cfg_access was designed for the use case that a single
context, the IPR driver, temporarily delays user space accesses to the
config space via sysfs. This assumption became invalid by the time
pci_dev_reset was added as locking instance. Today, if you run two loops
in parallel that reset the same device via sysfs, you end up with a
kernel BUG as pci_block_user_cfg_access detect the broken assumption.
This reworks the pci_block_user_cfg_access to a sleeping service
pci_cfg_access_lock and an atomic-compatible variant called
pci_cfg_access_trylock. The former not only blocks user space access as
before but also waits if access was already locked. The latter service
just returns false in this case, allowing the caller to resolve the
conflict instead of raising a BUG.
Adaptions of the ipr driver were originally written by Brian King.
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
I noticed that hotplug of one setup does not work with recent change in
pci tree.
After checking the bridge conf setup, I noticed that the bridges get
assigned but do not get enabled.
The reason is the following commit, while simply ignores bridge
resources when enabling a pci device:
| commit bbef98ab0f
| Author: Ram Pai <linuxram@us.ibm.com>
| Date: Sun Nov 6 10:33:10 2011 +0800
|
| PCI: defer enablement of SRIOV BARS
|...
| NOTE: Note, there is subtle change in the pci_enable_device() API. Any
| driver that depends on SRIOV BARS to be enabled in pci_enable_device()
| can fail.
Put back bridge resource and ROM resource checking to fix the problem.
That should fix regression like BIOS does not assign correct resource to
bridge.
Discussion can be found at:
http://www.spinics.net/lists/linux-pci/msg12874.html
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During test of one IB card with guest VM, found that, msi is not
initialized properly.
It turns out __write_msi_msg will do nothing if device current_state is
not PCI_D0. And, that pci device does not have pm_cap in guest VM.
There is an error in setting of power state to PCI_D0 in
pci_enable_device(), but error is not returned for this. Following is
code flow:
pci_enable_device() --> __pci_enable_device_flags() -->
do_pci_enable_device() --> pci_set_power_state() -->
__pci_start_power_transition()
We have following condition inside __pci_start_power_transition():
if (platform_pci_power_manageable(dev)) {
error = platform_pci_set_power_state(dev, state);
if (!error)
pci_update_current_state(dev, state);
} else {
error = -ENODEV;
/* Fall back to PCI_D0 if native PM is not supported */
if (!dev->pm_cap)
dev->current_state = PCI_D0;
}
Here, from platform_pci_set_power_state(), acpi_pci_set_power_state() is
getting called and that is failing with ENODEV because of following
condition:
if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0",&tmp)))
return -ENODEV;
Because of that, pci_update_current_state() is not getting called.
With this patch, if device power state can not be set via
platform_pci_set_power_state and that device does not have native pm
support, then PCI device power state will be set to PCI_D0.
-v2: This also reverts 47e9037ac1, as it's
not needed after this change.
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Ajaykumar Hotchandani<ajaykumar.hotchandani@oracle.com>
Signed-off-by: Yinghai Lu<yinghai.lu@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
All the PCI BARs of a device are enabled when the device is enabled
using pci_enable_device(). This unnecessarily enables SRIOV BARs of the
device.
On some platforms, which do not support SRIOV as yet, the
pci_enable_device() fails to enable the device if its SRIOV BARs are not
allocated resources correctly.
The following patch fixes the above problem. The SRIOV BARs are now
enabled when IOV capability of the device is enabled in sriov_enable().
NOTE: Note, there is subtle change in the pci_enable_device() API. Any
driver that depends on SRIOV BARS to be enabled in pci_enable_device()
can fail.
The patch has been touch tested on power and x86 platform.
Tested-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
When configuring the PCIe settings for "performance", we allow parents
to have a larger Max Payload Size than children and rely on children
Max Read Request Size to not be larger than their own MPS to avoid
having the host bridge generate responses they can't cope with.
However, various drivers in Linux call pci_set_readrq() with arbitrary
values, assuming this to be a simple performance tweak. This breaks
under our "performance" configuration.
Fix that by making sure the value programmed by pcie_set_readrq() is
never larger than the configured MPS for that device.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jon Mason <mason@myri.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
