Commit Graph

144 Commits

Author SHA1 Message Date
Heiner Kallweit
1fd46d3277 PCI/ASPM: Fix L1 substate handling in aspm_attr_store_common()
commit 8e37372ad0bea4c9b4712d9943f6ae96cff9491f upstream.

aspm_attr_store_common(), which handles sysfs control of ASPM, has the same
problem as fb097dcd5a28 ("PCI/ASPM: Disable only ASPM_STATE_L1 when driver
disables L1"): disabling L1 adds only ASPM_L1 (but not any of the L1.x
substates) to the "aspm_disable" mask.

Enabling one substate, e.g., L1.1, via sysfs removes ASPM_L1 from the
disable mask.  Since disabling L1 via sysfs doesn't add any of the
substates to the disable mask, enabling L1.1 actually enables *all* the
substates.

In this scenario:

  - Write 0 to "l1_aspm" to disable L1
  - Write 1 to "l1_1_aspm" to enable L1.1

the intention is to disable L1 and all L1.x substates, then enable just
L1.1, but in fact, *all* L1.x substates are enabled.

Fix this by explicitly disabling all the L1.x substates when disabling L1.

Fixes: 72ea91afbf ("PCI/ASPM: Add sysfs attributes for controlling ASPM link states")
Link: https://lore.kernel.org/r/6ba7dd79-9cfe-4ed0-a002-d99cb842f361@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 16:54:57 +00:00
Ilpo Järvinen
69795c689e PCI/ASPM: Use RMW accessors for changing LNKCTL
[ Upstream commit e09060b3b6b4661278ff8e1b7b81a37d5ea86eae ]

Don't assume that the device is fully under the control of ASPM and use RMW
capability accessors which do proper locking to avoid losing concurrent
updates to the register values.

If configuration fails in pcie_aspm_configure_common_clock(), the
function attempts to restore the old PCI_EXP_LNKCTL_CCC settings. Store
only the old PCI_EXP_LNKCTL_CCC bit for the relevant devices rather
than the content of the whole LNKCTL registers. It aligns better with
how pcie_lnkctl_clear_and_set() expects its parameter and makes the
code more obvious to understand.

Suggested-by: Lukas Wunner <lukas@wunner.de>
Fixes: 2a42d9dba7 ("PCIe: ASPM: Break out of endless loop waiting for PCI config bits to switch")
Fixes: 7d715a6c1a ("PCI: add PCI Express ASPM support")
Link: https://lore.kernel.org/r/20230717120503.15276-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19 12:20:14 +02:00
Ilpo Järvinen
838d6e86ec PCI/ASPM: Avoid link retraining race
[ Upstream commit e7e39756363ad5bd83ddeae1063193d0f13870fd ]

PCIe r6.0.1, sec 7.5.3.7, recommends setting the link control parameters,
then waiting for the Link Training bit to be clear before setting the
Retrain Link bit.

This avoids a race where the LTSSM may not use the updated parameters if it
is already in the midst of link training because of other normal link
activity.

Wait for the Link Training bit to be clear before toggling the Retrain Link
bit to ensure that the LTSSM uses the updated link control parameters.

[bhelgaas: commit log, return 0 (success)/-ETIMEDOUT instead of bool for
both pcie_wait_for_retrain() and the existing pcie_retrain_link()]
Suggested-by: Lukas Wunner <lukas@wunner.de>
Fixes: 7d715a6c1a ("PCI: add PCI Express ASPM support")
Link: https://lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-11 11:57:32 +02:00
Ilpo Järvinen
9f283ca643 PCI/ASPM: Factor out pcie_wait_for_retrain()
[ Upstream commit 9c7f136433d26592cb4d9cd00b4e15c33d9797c6 ]

Factor pcie_wait_for_retrain() out from pcie_retrain_link().  No functional
change intended.

[bhelgaas: split out from
https: //lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com]
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Stable-dep-of: e7e39756363a ("PCI/ASPM: Avoid link retraining race")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-11 11:57:32 +02:00
Bjorn Helgaas
ffc0ee491f PCI/ASPM: Return 0 or -ETIMEDOUT from pcie_retrain_link()
[ Upstream commit f5297a01ee805d7fa569d288ed65fc0f9ac9b03d ]

"pcie_retrain_link" is not a question with a true/false answer, so "bool"
isn't quite the right return type.  Return 0 for success or -ETIMEDOUT if
the retrain failed.  No functional change intended.

[bhelgaas: based on Ilpo's patch below]
Link: https://lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Stable-dep-of: e7e39756363a ("PCI/ASPM: Avoid link retraining race")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-11 11:57:32 +02:00
Ding Hui
7badf4d6f4 PCI/ASPM: Disable ASPM on MFD function removal to avoid use-after-free
[ Upstream commit 456d8aa37d0f56fc9e985e812496e861dcd6f2f2 ]

Struct pcie_link_state->downstream is a pointer to the pci_dev of function
0.  Previously we retained that pointer when removing function 0, and
subsequent ASPM policy changes dereferenced it, resulting in a
use-after-free warning from KASAN, e.g.:

  # echo 1 > /sys/bus/pci/devices/0000:03:00.0/remove
  # echo powersave > /sys/module/pcie_aspm/parameters/policy

  BUG: KASAN: slab-use-after-free in pcie_config_aspm_link+0x42d/0x500
  Call Trace:
   kasan_report+0xae/0xe0
   pcie_config_aspm_link+0x42d/0x500
   pcie_aspm_set_policy+0x8e/0x1a0
   param_attr_store+0x162/0x2c0
   module_attr_store+0x3e/0x80

PCIe spec r6.0, sec 7.5.3.7, recommends that software program the same ASPM
Control value in all functions of multi-function devices.

Disable ASPM and free the pcie_link_state when any child function is
removed so we can discard the dangling pcie_link_state->downstream pointer
and maintain the same ASPM Control configuration for all functions.

[bhelgaas: commit log and comment]
Debugged-by: Zongquan Qin <qinzongquan@sangfor.com.cn>
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Fixes: b5a0a9b59c ("PCI/ASPM: Read and set up L1 substate capabilities")
Link: https://lore.kernel.org/r/20230507034057.20970-1-dinghui@sangfor.com.cn
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-27 08:43:56 +02:00
Saheed O. Bolarinwa
df8f10587d PCI/ASPM: Remove struct pcie_link_state.l1ss
Previously we computed L1.2 parameters in the enumeration path, saved them
in struct pcie_link_state.l1ss, and programmed them into the devices
whenever we enabled or disabled L1.2 on the link.  But these parameters are
constant and don't need to be updated when enabling/disabling L1.2.

Compute and program the L1.2 parameters once during enumeration and remove
the struct pcie_link_state.l1ss member.  No functional change intended.

[bhelgaas: rework to program L1.2 parameters during enumeration]
Link: https://lore.kernel.org/r/20201015193039.12585-13-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:21:19 -05:00
Saheed O. Bolarinwa
187f91db82 PCI/ASPM: Remove struct aspm_register_info.l1ss_cap
Previously we stored the L1SS Capabilities value in the struct
aspm_register_info.

We only need this information in one place, so read it there and remove
struct aspm_register_info completely, since it's now empty.  No functional
change intended.

[bhelgaas: split up, don't cache l1ss_cap in pci_dev]
Link: https://lore.kernel.org/r/20201015193039.12585-12-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:21:15 -05:00
Bjorn Helgaas
1e8955fd83 PCI/ASPM: Pass L1SS Capabilities value, not struct aspm_register_info
aspm_calc_l1ss_info() needs only the L1SS Capabilities.  It doesn't need
anything else from struct aspm_register_info, so pass only the Capabilities
value.  No functional change intended.

Link: https://lore.kernel.org/r/20201015193039.12585-11-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:21:12 -05:00
Saheed O. Bolarinwa
28a1488e55 PCI/ASPM: Remove struct aspm_register_info.l1ss_ctl1
Previously we stored the L1SS Control 1 register in the struct
aspm_register_info.

We only need this information in one place, so read it there and remove it
from struct aspm_register_info.  No functional change intended.

[bhelgaas: split ctl1/ctl2]
Link: https://lore.kernel.org/r/20201015193039.12585-10-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:21:09 -05:00
Bjorn Helgaas
81c2b807c8 PCI/ASPM: Remove struct aspm_register_info.l1ss_ctl2 (unused)
We never use the aspm_register_info.l1ss_ctl2 value, so remove it.  No
functional change intended.

Link: https://lore.kernel.org/r/20201015193039.12585-9-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:21:07 -05:00
Saheed O. Bolarinwa
ecdf57b4f6 PCI/ASPM: Remove struct aspm_register_info.l1ss_cap_ptr
Save the L1 Substates Capability pointer in struct pci_dev.  Then we don't
have to keep track of it in the struct aspm_register_info and struct
pcie_link_state, which makes the code easier to read.  No functional change
intended.

[bhelgaas: split to a separate patch]
Link: https://lore.kernel.org/r/20201015193039.12585-8-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:21:04 -05:00
Saheed O. Bolarinwa
5f7875d651 PCI/ASPM: Remove struct aspm_register_info.latency_encoding
Previously we stored L0s and L1 Exit Latency information from the Link
Capabilities register in the struct aspm_register_info.

We only need these latencies when we already have the Link Capabilities
values, so use those directly and remove the latencies from struct
aspm_register_info.  No functional change intended.

Link: https://lore.kernel.org/r/20201015193039.12585-7-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:21:02 -05:00
Saheed O. Bolarinwa
67bcc9ad68 PCI/ASPM: Remove struct aspm_register_info.enabled
Previously we stored the "ASPM Control" bits from the Link Control register
in the struct aspm_register_info.

Read PCI_EXP_LNKCTL directly when needed.  This means we can use the
PCI_EXP_LNKCTL_ASPM_* bits directly instead of the similar but different
PCIE_LINK_STATE_* bits.  No functional change intended.

[bhelgaas: drop get_aspm_enable() and read LNKCTL once directly]
Link: https://lore.kernel.org/r/20201015193039.12585-6-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:20:59 -05:00
Saheed O. Bolarinwa
c6e5f02b52 PCI/ASPM: Remove struct aspm_register_info.support
Previously we stored the "ASPM Support" field from the Link Capabilities
register in the struct aspm_register_info.

Read the Link Capabilities directly when needed and remove it from the
struct aspm_register_info.  No functional change intended.

[bhelgaas: remove pci_dev cached copy since LNKCAP isn't truly read-only,
add PCI_EXP_LNKCAP_ASPM_L0S & PCI_EXP_LNKCAP_ASPM_L1, check them directly
instead of adding aspm_support()]
Link: https://lore.kernel.org/r/20201015193039.12585-5-helgaas@kernel.org
Signed-off-by: Saheed O. Bolarinwa <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:20:53 -05:00
Bjorn Helgaas
190cd42cc1 PCI/ASPM: Use 'parent' and 'child' for readability
Other users of link->pdev and link->downstream, e.g., pcie_aspm_cap_init(),
pcie_config_aspm_l1ss(), and pcie_config_aspm_link(), use "parent" and
"child" as local names.

Do the same in aspm_calc_l1ss_info() for readability.  No functional change
intended.

Link: https://lore.kernel.org/r/20201015193039.12585-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:20:51 -05:00
Bjorn Helgaas
08e869ee16 PCI/ASPM: Move LTR path check to where it's used
pcie_get_aspm_reg() mostly reads ASPM-related registers, but in some cases
it also updates the value read from PCI_L1SS_CAP based on LTR properties.

Move this update to the point where the value is used to make the code more
readable.

No functional change intended, although previously we could clear
PCI_L1SS_CAP_ASPM_L1_2 for both ends of the link, and now we'll only do it
for the downstream end of a link.  This shouldn't matter because we always
test that bit by ANDing l1ss_cap for the upstream and downstream ends.

Link: https://lore.kernel.org/r/20201015193039.12585-3-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:20:48 -05:00
Bjorn Helgaas
0f1619cf82 PCI/ASPM: Move pci_clear_and_set_dword() earlier
Move pci_clear_and_set_dword() earlier in file to prepare for future patch.
No functional change intended.

Link: https://lore.kernel.org/r/20201015193039.12585-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-10-16 11:20:45 -05:00
Xiongfeng Wang
3167e3d340 PCI/ASPM: Add missing newline in sysfs 'policy'
When I cat ASPM parameter 'policy' by sysfs, it displays as follows.  Add a
newline for easy reading.  Other sysfs attributes already include a
newline.

  [root@localhost ~]# cat /sys/module/pcie_aspm/parameters/policy
  [default] performance powersave powersupersave [root@localhost ~]#

Fixes: 7d715a6c1a ("PCI: add PCI Express ASPM support")
Link: https://lore.kernel.org/r/1594972765-10404-1-git-send-email-wangxiongfeng2@huawei.com
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-07-17 16:01:24 -05:00
Kai-Heng Feng
66ff14e59e PCI/ASPM: Allow ASPM on links to PCIe-to-PCI/PCI-X Bridges
7d715a6c1a ("PCI: add PCI Express ASPM support") added the ability for
Linux to enable ASPM, but for some undocumented reason, it didn't enable
ASPM on links where the downstream component is a PCIe-to-PCI/PCI-X Bridge.

Remove this exclusion so we can enable ASPM on these links.

The Dell OptiPlex 7080 mentioned in the bugzilla has a TI XIO2001
PCIe-to-PCI Bridge.  Enabling ASPM on the link leading to it allows the
Intel SoC to enter deeper Package C-states, which is a significant power
savings.

[bhelgaas: commit log]
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207571
Link: https://lore.kernel.org/r/20200505173423.26968-1-kai.heng.feng@canonical.com
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2020-05-07 16:39:44 -05:00
Chris Packham
3b364c659b PCI/ASPM: Reduce severity of common clock config message
When the UEFI/BIOS or bootloader has not initialised a PCIe device we would
get the following message:

  kern.warning: pci 0000:00:01.0: ASPM: current common clock configuration is broken, reconfiguring

"warning" and "broken" are slightly misleading. On an embedded system it is
quite possible for the bootloader to avoid configuring PCIe devices if they
are not needed.

Downgrade the message to pci_info() and change "broken" to "inconsistent"
since we fix up the inconsistency in the code immediately following the
message (and emit an error if that fails).

Link: https://lore.kernel.org/r/20200323035530.11569-1-chris.packham@alliedtelesis.co.nz
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2020-03-28 15:09:22 -05:00
Yicong Yang
58a3862a10 PCI/ASPM: Clear the correct bits when enabling L1 substates
In pcie_config_aspm_l1ss(), we cleared the wrong bits when enabling ASPM L1
Substates.  Instead of the L1.x enable bits (PCI_L1SS_CTL1_L1SS_MASK, 0xf), we
cleared the Link Activation Interrupt Enable bit (PCI_L1SS_CAP_L1_PM_SS,
0x10).

Clear the L1.x enable bits before writing the new L1.x configuration.

[bhelgaas: changelog]
Fixes: aeda9adeba ("PCI/ASPM: Configure L1 substate settings")
Link: https://lore.kernel.org/r/1584093227-1292-1-git-send-email-yangyicong@hisilicon.com
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org	# v4.11+
2020-03-18 17:43:14 -05:00
Heiner Kallweit
87e90283c9 PCI/ASPM: Remove PCIEASPM_DEBUG Kconfig option and related code
Previously, CONFIG_PCIEASPM_DEBUG enabled "link_state" and "clk_ctl" sysfs
files that controlled ASPM.  We believe these files were rarely if ever
used.

We recently added sysfs ASPM controls that are always present, so the debug
code is no longer needed.  Removing this debug code has been discussed for
quite some time, see e.g. [0].

Remove PCIEASPM_DEBUG and the related code.

[0] https://lore.kernel.org/lkml/20180727202619.GD173328@bhelgaas-glaptop.roam.corp.google.com/
Link: https://lore.kernel.org/r/ec935d8e-c084-3938-f1d1-748617596b25@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-11-21 17:31:46 -06:00
Heiner Kallweit
72ea91afbf PCI/ASPM: Add sysfs attributes for controlling ASPM link states
Add sysfs attributes to Endpoints and other Upstream Ports to control ASPM,
Clock PM, and L1 PM Substates.  The new attributes are:

  /sys/devices/pci*/.../link/clkpm
  /sys/devices/pci*/.../link/l0s_aspm
  /sys/devices/pci*/.../link/l1_aspm
  /sys/devices/pci*/.../link/l1_1_aspm
  /sys/devices/pci*/.../link/l1_2_aspm
  /sys/devices/pci*/.../link/l1_1_pcipm
  /sys/devices/pci*/.../link/l1_2_pcipm

An attribute is only visible if both ends of the Link leading to the device
support the state.  Writing y/1/on to the file enables the state; n/0/off
disables it.

These attributes can be used to tune the power/performance tradeoff for
individual devices.

[bhelgaas: commit log, rename directory to "link"]
Link: https://lore.kernel.org/r/b1c83f8a-9bf6-eac5-82d0-cf5b90128fbf@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-11-21 17:30:24 -06:00
Heiner Kallweit
687aaf386a PCI/ASPM: Add pcie_aspm_get_link()
Factor out getting the link associated with a pci_dev and use this helper
where appropriate.  In addition this helper will be used in a subsequent
patch of this series.

Link: https://lore.kernel.org/r/19d33770-29de-a9af-4d85-f2b30269d383@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-10-15 15:22:59 -05:00
Heiner Kallweit
35efea32b2 PCI/ASPM: Allow re-enabling Clock PM
Previously Clock PM could not be re-enabled after being disabled by
pci_disable_link_state() because clkpm_capable was reset.  Change this by
adding a clkpm_disable field similar to aspm_disable.

Link: https://lore.kernel.org/r/4e8a66db-7d53-4a66-c26c-f0037ffaa705@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-10-15 15:10:13 -05:00
Heiner Kallweit
aff5d0552d PCI/ASPM: Add L1 PM substate support to pci_disable_link_state()
Add support for disabling states L1.1 and L1.2 to pci_disable_link_state().
Allow separate control of ASPM and PCI PM L1 substates.

Link: https://lore.kernel.org/r/d81f8036-c236-6463-48e7-ebcdcda85bba@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-10-15 14:25:58 -05:00
Bjorn Helgaas
5e0c21c75e PCI/ASPM: Remove pcie_aspm_enabled() unnecessary locking
The lifetime of the link_state structure (bridge->link_state) is not the
same as the lifetime of "bridge" itself.  The link_state is allocated by
pcie_aspm_init_link_state() after children of the bridge have been
enumerated, and it is deallocated by pcie_aspm_exit_link_state() after all
children of the bridge (but not the bridge itself) have been removed.

Previously pcie_aspm_enabled() acquired aspm_lock to ensure that
link_state was not deallocated while we're looking at it.  But the fact
that the caller of pcie_aspm_enabled() holds a reference to @pdev means
there's always at least one child of the bridge, which means link_state
can't be deallocated.

Remove the unnecessary locking in pcie_aspm_enabled().

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-15 14:25:15 -05:00
Linus Torvalds
299d14d4c3 Merge tag 'pci-v5.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
 "Enumeration:

   - Consolidate _HPP/_HPX stuff in pci-acpi.c and simplify it
     (Krzysztof Wilczynski)

   - Fix incorrect PCIe device types and remove dev->has_secondary_link
     to simplify code that deals with upstream/downstream ports (Mika
     Westerberg)

   - After suspend, restore Resizable BAR size bits correctly for 1MB
     BARs (Sumit Saxena)

   - Enable PCI_MSI_IRQ_DOMAIN support for RISC-V (Wesley Terpstra)

  Virtualization:

   - Add ACS quirks for iProc PAXB (Abhinav Ratna), Amazon Annapurna
     Labs (Ali Saidi)

   - Move sysfs SR-IOV functions to iov.c (Kelsey Skunberg)

   - Remove group write permissions from sysfs sriov_numvfs,
     sriov_drivers_autoprobe (Kelsey Skunberg)

  Hotplug:

   - Simplify pciehp indicator control (Denis Efremov)

  Peer-to-peer DMA:

   - Allow P2P DMA between root ports for whitelisted bridges (Logan
     Gunthorpe)

   - Whitelist some Intel host bridges for P2P DMA (Logan Gunthorpe)

   - DMA map P2P DMA requests that traverse host bridge (Logan
     Gunthorpe)

  Amazon Annapurna Labs host bridge driver:

   - Add DT binding and controller driver (Jonathan Chocron)

  Hyper-V host bridge driver:

   - Fix hv_pci_dev->pci_slot use-after-free (Dexuan Cui)

   - Fix PCI domain number collisions (Haiyang Zhang)

   - Use instance ID bytes 4 & 5 as PCI domain numbers (Haiyang Zhang)

   - Fix build errors on non-SYSFS config (Randy Dunlap)

  i.MX6 host bridge driver:

   - Limit DBI register length (Stefan Agner)

  Intel VMD host bridge driver:

   - Fix config addressing issues (Jon Derrick)

  Layerscape host bridge driver:

   - Add bar_fixed_64bit property to endpoint driver (Xiaowei Bao)

   - Add CONFIG_PCI_LAYERSCAPE_EP to build EP/RC drivers separately
     (Xiaowei Bao)

  Mediatek host bridge driver:

   - Add MT7629 controller support (Jianjun Wang)

  Mobiveil host bridge driver:

   - Fix CPU base address setup (Hou Zhiqiang)

   - Make "num-lanes" property optional (Hou Zhiqiang)

  Tegra host bridge driver:

   - Fix OF node reference leak (Nishka Dasgupta)

   - Disable MSI for root ports to work around design problem (Vidya
     Sagar)

   - Add Tegra194 DT binding and controller support (Vidya Sagar)

   - Add support for sideband pins and slot regulators (Vidya Sagar)

   - Add PIPE2UPHY support (Vidya Sagar)

  Misc:

   - Remove unused pci_block_cfg_access() et al (Kelsey Skunberg)

   - Unexport pci_bus_get(), etc (Kelsey Skunberg)

   - Hide PM, VC, link speed, ATS, ECRC, PTM constants and interfaces in
     the PCI core (Kelsey Skunberg)

   - Clean up sysfs DEVICE_ATTR() usage (Kelsey Skunberg)

   - Mark expected switch fall-through (Gustavo A. R. Silva)

   - Propagate errors for optional regulators and PHYs (Thierry Reding)

   - Fix kernel command line resource_alignment parameter issues (Logan
     Gunthorpe)"

* tag 'pci-v5.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (112 commits)
  PCI: Add pci_irq_vector() and other stubs when !CONFIG_PCI
  arm64: tegra: Add PCIe slot supply information in p2972-0000 platform
  arm64: tegra: Add configuration for PCIe C5 sideband signals
  PCI: tegra: Add support to enable slot regulators
  PCI: tegra: Add support to configure sideband pins
  PCI: vmd: Fix shadow offsets to reflect spec changes
  PCI: vmd: Fix config addressing when using bus offsets
  PCI: dwc: Add validation that PCIe core is set to correct mode
  PCI: dwc: al: Add Amazon Annapurna Labs PCIe controller driver
  dt-bindings: PCI: Add Amazon's Annapurna Labs PCIe host bridge binding
  PCI: Add quirk to disable MSI-X support for Amazon's Annapurna Labs Root Port
  PCI/VPD: Prevent VPD access for Amazon's Annapurna Labs Root Port
  PCI: Add ACS quirk for Amazon Annapurna Labs root ports
  PCI: Add Amazon's Annapurna Labs vendor ID
  MAINTAINERS: Add PCI native host/endpoint controllers designated reviewer
  PCI: hv: Use bytes 4 and 5 from instance ID as the PCI domain numbers
  dt-bindings: PCI: tegra: Add PCIe slot supplies regulator entries
  dt-bindings: PCI: tegra: Add sideband pins configuration entries
  PCI: tegra: Add Tegra194 PCIe support
  PCI: Get rid of dev->has_secondary_link flag
  ...
2019-09-23 19:16:01 -07:00
Bjorn Helgaas
a10a1f60c7 Merge branch 'pci/enumeration'
- Consolidate _HPP & _HPX code in pci-acpi.h and remove unnecessary
    struct hotplug_program_ops (Krzysztof Wilczynski)

  - Fixup PCIe device types to remove the need for dev->has_secondary_link
    (Mika Westerberg)

* pci/enumeration:
  PCI: Get rid of dev->has_secondary_link flag
  PCI: Make pcie_downstream_port() available outside of access.c
  PCI/ACPI: Remove unnecessary struct hotplug_program_ops
  PCI/ACPI: Move _HPP & _HPX functions to pci-acpi.c
  PCI/ACPI: Rename _HPX structs from hpp_* to hpx_*
2019-09-23 16:10:08 -05:00
Mika Westerberg
ca78410403 PCI: Get rid of dev->has_secondary_link flag
In some systems, the Device/Port Type in the PCI Express Capabilities
register incorrectly identifies upstream ports as downstream ports.

d0751b98df ("PCI: Add dev->has_secondary_link to track downstream PCIe
links") addressed this by adding pci_dev.has_secondary_link, which is set
for downstream ports.  But this is confusing because pci_pcie_type()
sometimes gives the wrong answer, and it's not obvious that we should use
pci_dev.has_secondary_link instead.

Reduce the confusion by correcting the type of the port itself so that
pci_pcie_type() returns the actual type regardless of what the Device/Port
Type register claims it is.  Update the users to call pci_pcie_type() and
pcie_downstream_port() accordingly, and remove pci_dev.has_secondary_link
completely.

Link: https://lore.kernel.org/linux-pci/20190703133953.GK128603@google.com/
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20190822085553.62697-2-mika.westerberg@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-09-07 07:45:31 -05:00
Krzysztof Wilczynski
7ce2e76a04 PCI: Move ASPM declarations to linux/pci.h
Move ASPM definitions and function prototypes from include/linux/pci-aspm.h
to include/linux/pci.h so users only need to include <linux/pci.h>:

  PCIE_LINK_STATE_L0S
  PCIE_LINK_STATE_L1
  PCIE_LINK_STATE_CLKPM
  pci_disable_link_state()
  pci_disable_link_state_locked()
  pcie_no_aspm()

No functional changes intended.

Link: https://lore.kernel.org/r/20190827095620.11213-1-kw@linux.com
Signed-off-by: Krzysztof Wilczynski <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-08-28 08:28:39 -05:00
Rafael J. Wysocki
accd2dd72c PCI/ASPM: Add pcie_aspm_enabled()
Add a function checking whether or not PCIe ASPM has been enabled for
a given device.

It will be used by the NVMe driver to decide how to handle the
device during system suspend.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
2019-08-12 10:47:55 +02:00
Heiner Kallweit
4cfd218855 PCI: let pci_disable_link_state propagate errors
Drivers may rely on pci_disable_link_state() having disabled certain
ASPM link states. If OS can't control ASPM then pci_disable_link_state()
turns into a no-op w/o informing the caller. The driver therefore may
falsely assume the respective ASPM link states are disabled.
Let pci_disable_link_state() propagate errors to the caller, enabling
the caller to react accordingly.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-21 22:05:42 -04:00
Stefan Mätje
658eec837b PCI: Rework pcie_retrain_link() wait loop
Transform wait code to a "do {} while (time_before())" loop as recommended
by reviewer.  No functional change intended.

Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-04-06 09:25:53 -05:00
Stefan Mätje
4ec73791a6 PCI: Work around Pericom PCIe-to-PCI bridge Retrain Link erratum
Due to an erratum in some Pericom PCIe-to-PCI bridges in reverse mode
(conventional PCI on primary side, PCIe on downstream side), the Retrain
Link bit needs to be cleared manually to allow the link training to
complete successfully.

If it is not cleared manually, the link training is continuously restarted
and no devices below the PCI-to-PCIe bridge can be accessed.  That means
drivers for devices below the bridge will be loaded but won't work and may
even crash because the driver is only reading 0xffff.

See the Pericom Errata Sheet PI7C9X111SLB_errata_rev1.2_102711.pdf for
details.  Devices known as affected so far are: PI7C9X110, PI7C9X111SL,
PI7C9X130.

Add a new flag, clear_retrain_link, in struct pci_dev.  Quirks for affected
devices set this bit.

Note that pcie_retrain_link() lives in aspm.c because that's currently the
only place we use it, but this erratum is not specific to ASPM, and we may
retrain links for other reasons in the future.

Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
[bhelgaas: apply regardless of CONFIG_PCIEASPM]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: stable@vger.kernel.org
2019-04-06 09:25:47 -05:00
Stefan Mätje
86fa6a3442 PCI: Factor out pcie_retrain_link() function
Factor out pcie_retrain_link() to use for Pericom Retrain Link quirk.  No
functional change intended.

Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: stable@vger.kernel.org
2019-04-06 09:25:35 -05:00
Linus Torvalds
926b02d3eb Merge tag 'pci-v4.21-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:

 - Remove unused lists from ASPM pcie_link_state (Frederick Lawler)

 - Fix Broadcom CNB20LE host bridge unintended sign extension (Colin Ian
   King)

 - Expand Kconfig "PF" acronyms (Randy Dunlap)

 - Update MAINTAINERS for arch/x86/kernel/early-quirks.c (Bjorn Helgaas)

 - Add missing include to drivers/pci.h (Alexandru Gagniuc)

 - Override Synopsys USB 3.x HAPS device class so dwc3-haps can claim it
   instead of xhci (Thinh Nguyen)

 - Clean up P2PDMA documentation (Randy Dunlap)

 - Allow runtime PM even if driver doesn't supply callbacks (Jarkko
   Nikula)

 - Remove status check after submitting Switchtec MRPC Firmware Download
   commands to avoid Completion Timeouts (Kelvin Cao)

 - Set Switchtec coherent DMA mask to allow 64-bit DMA (Boris Glimcher)

 - Fix Switchtec SWITCHTEC_IOCTL_EVENT_IDX_ALL flag overwrite issue
   (Joey Zhang)

 - Enable write combining for Switchtec MRPC Input buffers (Kelvin Cao)

 - Add Switchtec MRPC DMA mode support (Wesley Sheng)

 - Skip VF scanning on powerpc, which does this in firmware (Sebastian
   Ott)

 - Add Amlogic Meson PCIe controller driver and DT bindings (Yue Wang)

 - Constify histb dw_pcie_host_ops structure (Julia Lawall)

 - Support multiple power domains for imx6 (Leonard Crestez)

 - Constify layerscape driver data (Stefan Agner)

 - Update imx6 Kconfig to allow imx6 PCIe in imx7 kernel (Trent Piepho)

 - Support armada8k GPIO reset (Baruch Siach)

 - Support suspend/resume support on imx6 (Leonard Crestez)

 - Don't hard-code DesignWare DBI/ATU offst (Stephen Warren)

 - Skip i.MX6 PHY setup on i.MX7D (Andrey Smirnov)

 - Remove Jianguo Sun from HiSilicon STB maintainers (Lorenzo Pieralisi)

 - Mask DesignWare interrupts instead of disabling them to avoid lost
   interrupts (Marc Zyngier)

 - Add locking when acking DesignWare interrupts (Marc Zyngier)

 - Ack DesignWare interrupts in the proper callbacks (Marc Zyngier)

 - Use devm resource parser in mediatek (Honghui Zhang)

 - Remove unused mediatek "num-lanes" DT property (Honghui Zhang)

 - Add UniPhier PCIe controller driver and DT bindings (Kunihiko
   Hayashi)

 - Enable MSI for imx6 downstream components (Richard Zhu)

* tag 'pci-v4.21-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (40 commits)
  PCI: imx: Enable MSI from downstream components
  s390/pci: skip VF scanning
  PCI/IOV: Add flag so platforms can skip VF scanning
  PCI/IOV: Factor out sriov_add_vfs()
  PCI: uniphier: Add UniPhier PCIe host controller support
  dt-bindings: PCI: Add UniPhier PCIe host controller description
  PCI: amlogic: Add the Amlogic Meson PCIe controller driver
  dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller
  arm64: dts: mt7622: Remove un-used property for PCIe
  arm: dts: mt7623: Remove un-used property for PCIe
  dt-bindings: PCI: MediaTek: Remove un-used property
  PCI: mediatek: Remove un-used variant in struct mtk_pcie_port
  MAINTAINERS: Remove Jianguo Sun from HiSilicon STB DWC entry
  PCI: dwc: Don't hard-code DBI/ATU offset
  PCI: imx: Add imx6sx suspend/resume support
  PCI: armada8k: Add support for gpio controlled reset signal
  PCI: dwc: Adjust Kconfig to allow IMX6 PCIe host on IMX7
  PCI: dwc: layerscape: Constify driver data
  PCI: imx: Add multi-pd support
  PCI: Override Synopsys USB 3.x HAPS device class
  ...
2019-01-05 17:57:34 -08:00
Frederick Lawler
3c259a1c36 PCI/ASPM: Remove unused lists from struct pcie_link_state
ASPM does not make use of the children or link LIST_HEADs declared in
struct pcie_link_state and defined in alloc_pcie_link_state().  Therefore,
remove these lists.

No functional change intended.

Signed-off-by: Frederick Lawler <fred@fredlawl.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-12-17 14:30:31 -06:00
Bjorn Helgaas
b07b864ee4 Revert "PCI/ASPM: Do not initialize link state when aspm_disabled is set"
This reverts commit 17c9148736.

Rafael found that this commit broke the SD card reader in his
Acer Aspire S5.  Details of the problem are in the bugzilla below.

Fixes: 17c9148736 ("PCI/ASPM: Do not initialize link state when aspm_disabled is set")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201801
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-12-03 18:05:17 -06:00
Patrick Talbert
17c9148736 PCI/ASPM: Do not initialize link state when aspm_disabled is set
Now that ASPM is configured for *all* PCIe devices at boot, a problem is
seen with systems that set the FADT NO_ASPM bit.  This bit indicates that
the OS should not alter the ASPM state, but when
pcie_aspm_init_link_state() runs it only checks for !aspm_support_enabled.
This misses the ACPI_FADT_NO_ASPM case because that is setting
aspm_disabled.

The result is systems may hang at boot after 1302fcf; avoidable if they
boot with pcie_aspm=off (sets !aspm_support_enabled).

Fix this by having aspm_init_link_state() check for either
!aspm_support_enabled or acpm_disabled.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=201001
Fixes: 1302fcf0d0 ("PCI: Configure *all* devices, not just hot-added ones")
Signed-off-by: Patrick Talbert <ptalbert@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-09-18 16:19:06 -05:00
Lukas Wunner
aeae4f3e5c PCI/ASPM: Fix link_state teardown on device removal
Upon removal of the last device on a bus, the link_state of the bridge
leading to that bus is sought to be torn down by having pci_stop_dev()
call pcie_aspm_exit_link_state().

When ASPM was originally introduced by commit 7d715a6c1a ("PCI: add
PCI Express ASPM support"), it determined whether the device being
removed is the last one by calling list_empty() on the bridge's
subordinate devices list.  That didn't work because the device is only
removed from the list slightly later in pci_destroy_dev().

Commit 3419c75e15 ("PCI: properly clean up ASPM link state on device
remove") attempted to fix it by calling list_is_last(), but that's not
correct either because it checks whether the device is at the *end* of
the list, not whether it's the last one *left* in the list.  If the user
removes the device which happens to be at the end of the list via sysfs
but other devices are preceding the device in the list, the link_state
is torn down prematurely.

The real fix is to move the invocation of pcie_aspm_exit_link_state() to
pci_destroy_dev() and reinstate the call to list_empty().  Remove a
duplicate check for dev->bus->self because pcie_aspm_exit_link_state()
already contains an identical check.

Fixes: 7d715a6c1a ("PCI: add PCI Express ASPM support")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: stable@vger.kernel.org # v2.6.26
2018-09-17 16:32:23 -05:00
Andy Shevchenko
36131ce9a0 PCI/ASPM: Convert to use sysfs_match_string() helper
The sysfs_match_string() helper returns index of the matching string in an
array.  Use it in pcie_aspm_set_policy() to simplify the code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[bhelgaas: squash sysfs_match_string() fix into original patch for issue
Reported-by: Heiner Kallweit <hkallweit1@gmail.com>]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-08-06 14:30:34 -05:00
Bjorn Helgaas
9ab105deb6 PCI/ASPM: Disable ASPM L1.2 Substate if we don't have LTR
When in the ASPM L1.0 state (but not the PCI-PM L1.0 state), the most
recent LTR value and the LTR_L1.2_THRESHOLD determines whether the link
enters the L1.2 substate.

If we don't have LTR enabled, prevent the use of ASPM L1.2.

PCI-PM L1.2 may still be used because it doesn't depend on
LTR_L1.2_THRESHOLD (see PCIe r4.0, sec 5.5.1).

Tested-by: Srinath Mannam <srinath.mannam@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-18 16:10:34 -05:00
Bjorn Helgaas
43b90eaed5 Merge branch 'pci/misc'
- use PCI_EXP_DEVCTL2_COMP_TIMEOUT in rapidio/tsi721 (Bjorn Helgaas)

  - remove possible NULL pointer dereference in of_pci_bus_find_domain_nr()
    (Shawn Lin)

  - report quirk timings with dev_info (Bjorn Helgaas)

  - report quirks that take longer than 10ms (Bjorn Helgaas)

  - add and use Altera Vendor ID (Johannes Thumshirn)

  - tidy Makefiles and comments (Bjorn Helgaas)

* pci/misc:
  PCI: Always define the of_node helpers
  PCI: Tidy comments
  PCI: Tidy Makefiles
  mcb: Add Altera PCI ID to mcb-pci
  PCI: Add Altera vendor ID
  PCI: Report quirks that take more than 10ms
  PCI: Report quirk timings with pci_info() instead of pr_debug()
  PCI: Fix NULL pointer dereference in of_pci_bus_find_domain_nr()
  rapidio/tsi721: use PCI_EXP_DEVCTL2_COMP_TIMEOUT macro
2018-04-04 13:27:45 -05:00
Bjorn Helgaas
df62ab5e0f PCI: Tidy comments
Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions.  No functional change
intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-03-19 14:20:43 -05:00
Sinan Kaya
04875177db PCI/ASPM: Don't warn if already in common clock mode
Previously we emitted a warning if we tried to configure common clock mode
the link was already configured to common clock mode by the UEFI BIOS.
Bail out silently in that case instead of emitting the warning:

  pci 0004:00:00.0: ASPM: Could not configure common clock

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
2018-02-28 15:00:55 -06:00
Gustavo A. R. Silva
f51af8a63c PCI/ASPM: Declare threshold_ns as u32, not u64
aspm_calc_l1ss_info() computes l1_2_threshold in microseconds as:

  l1_2_threshold = 2 + 4 + t_common_mode + t_power_on;

where t_common_mode is at most 255us:

  PCI_L1SS_CAP_CM_RESTORE_TIME  0x0000ff00   <-- 8 bits; <256us

and t_power_on is at most 31 * 100us = 3100us:

  PCI_L1SS_CAP_P_PWR_ON_VALUE   0x00f80000   <-- 5 bits; <32
  PCI_L1SS_CAP_P_PWR_ON_SCALE   0x00030000   <-- *2us, *10us, or *100us

So l1_2_threshold is at most 2 + 4 + 255 + 3100 = 3361, which means
threshold_ns is at most 3361 * 1000 = 3361000, which easily fits in a
u32.

Declare threshold_ns as u32, not u64.  This fixes a Coverity warning.

Addresses-Coverity-ID: 1462501
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
2018-02-28 14:39:53 -06:00
Bjorn Helgaas
412ee7cd3d Merge branch 'pci/misc' into next
* pci/misc:
  PCI: Add dummy pci_irqd_intx_xlate() for CONFIG_PCI=n build
  PCI: Add wrappers for dev_printk()
  PCI: Remove unnecessary messages for memory allocation failures
  PCI: Add #defines for Completion Timeout Disable feature
  hinic: Replace PCI pool old API
  net: e100: Replace PCI pool old API
  block: DAC960: Replace PCI pool old API
  MAINTAINERS: Include more PCI files
  PCI: Remove unneeded kallsyms include
  powerpc/pci: Unroll two pass loop when scanning bridges
  powerpc/pci: Use for_each_pci_bridge() helper
2018-01-31 10:10:32 -06:00
Frederick Lawler
7506dc7989 PCI: Add wrappers for dev_printk()
Add PCI-specific dev_printk() wrappers and use them to simplify the code
slightly.  No functional change intended.

Signed-off-by: Frederick Lawler <fred@fredlawl.com>
[bhelgaas: squash into one patch]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-01-18 12:55:24 -06:00