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>
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>
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
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
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>
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>
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>
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
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>
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>
- 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
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>
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>
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>
* 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
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>
Per PCIe r3.1, sec 5.5.1, LTR_L1.2_THRESHOLD determines whether we enter
the L1.2 Link state: if L1.2 is enabled and downstream devices have
reported that they can tolerate latency of at least LTR_L1.2_THRESHOLD, we
must enter L1.2 when CLKREQ# is de-asserted.
The implication is that LTR_L1.2_THRESHOLD is the time required to
transition the Link from L0 to L1.2 and back to L0, and per sec 5.5.3.3.1,
Figures 5-16 and 5-17, it appears that the absolute minimum time for those
transitions would be T(POWER_OFF) + T(L1.2) + T(POWER_ON) + T(COMMONMODE).
Therefore, compute LTR_L1.2_THRESHOLD as:
2us T(POWER_OFF)
+ 4us T(L1.2)
+ T(POWER_ON)
+ T(COMMONMODE)
= LTR_L1.2_THRESHOLD
Previously we set LTR_L1.2_THRESHOLD to a fixed value of 163840ns
(163.84us):
#define LTR_L1_2_THRESHOLD_BITS ((1 << 21) | (1 << 23) | (1 << 30))
((1 << 21) | (1 << 23) | (1 << 30)) = 0x40a00000
LTR_L1.2_THRESHOLD_Value = (0x40a00000 & 0x03ff0000) >> 16 = 0xa0 = 160
LTR_L1.2_THRESHOLD_Scale = (0x40a00000 & 0xe0000000) >> 29 = 0x2 (* 1024ns)
LTR_L1.2_THRESHOLD = 160 * 1024ns = 163840ns
Obviously this doesn't account for the circuit characteristics of different
implementations.
Note that while firmware may enable LTR, Linux itself currently does not
enable LTR. When L1.2 is enabled but LTR is not, LTR_L1.2_THRESHOLD is
ignored and we always enter L1.2 when it is enabled and CLKREQ# is
de-asserted. So this patch should not have any effect unless firmware
enables LTR.
Fixes: f1f0366dd6 ("PCI/ASPM: Calculate and save the L1.2 timing parameters")
Link: https://www.coreboot.org/pipermail/coreboot-gerrit/2015-March/021134.html
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Vidya Sagar <vidyas@nvidia.com>
Cc: Kenji Chen <kenji.chen@intel.com>
Cc: Patrick Georgi <pgeorgi@google.com>
Cc: Rajat Jain <rajatja@google.com>
Summary of modules changes for the 4.15 merge window:
- Treewide module_param_call() cleanup, fix up set/get function
prototype mismatches, from Kees Cook
- Minor code cleanups
Signed-off-by: Jessica Yu <jeyu@kernel.org>
-----BEGIN PGP SIGNATURE-----
iQIcBAABCgAGBQJaDCyzAAoJEMBFfjjOO8FyaYQP/AwHBy6XmwwVlWDP4BqIF6hL
Vhy3ccVLYEORvePv68tWSRPUz5n6+1Ebqanmwtkw6i8l+KwxY2SfkZql09cARc33
2iBE4bHF98iWQmnJbF6me80fedY9n5bZJNMQKEF9VozJWwTMOTQFTCfmyJRDBmk9
iidQj6M3idbSUOYIJjvc40VGx5NyQWSr+FFfqsz1rU5iLGRGEvA3I2/CDT0oTuV6
D4MmFxzE2Tv/vIMa2GzKJ1LGScuUfSjf93Lq9Kk0cG36qWao8l930CaXyVdE9WJv
bkUzpf3QYv/rDX6QbAGA0cada13zd+dfBr8YhchclEAfJ+GDLjMEDu04NEmI6KUT
5lP0Xw0xYNZQI7bkdxDMhsj5jaz/HJpXCjPCtZBnSEKiL4OPXVMe+pBHoCJ2/yFN
6M716XpWYgUviUOdiE+chczB5p3z4FA6u2ykaM4Tlk0btZuHGxjcSWwvcIdlPmjm
kY4AfDV6K0bfEBVguWPJicvrkx44atqT5nWbbPhDwTSavtsuRJLb3GCsHedx7K8h
ZO47lCQFAWCtrycK1HYw+oupNC3hYWQ0SR42XRdGhL1bq26C+1sei1QhfqSgA9PQ
7CwWH4UTOL9fhtrzSqZngYOh9sjQNFNefqQHcecNzcEjK2vjrgQZvRNWZKHSwaFs
fbGX8juZWP4ypbK+irTB
=c8vb
-----END PGP SIGNATURE-----
Merge tag 'modules-for-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull module updates from Jessica Yu:
"Summary of modules changes for the 4.15 merge window:
- treewide module_param_call() cleanup, fix up set/get function
prototype mismatches, from Kees Cook
- minor code cleanups"
* tag 'modules-for-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module: Do not paper over type mismatches in module_param_call()
treewide: Fix function prototypes for module_param_call()
module: Prepare to convert all module_param_call() prototypes
kernel/module: Delete an error message for a failed memory allocation in add_module_usage()
Add and use #defines for L1 Substate register fields instead of hard-coding
the masks. Also update comments to use names from the spec. No functional
change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Vidya Sagar <vidyas@nvidia.com>
Previously we programmed the LTR_L1.2_THRESHOLD in the parent (upstream)
device using the capability pointer of the *child* (downstream) device,
which corrupted some random word of the parent's config space.
Use the parent's L1 SS capability pointer to program its
LTR_L1.2_THRESHOLD.
Fixes: aeda9adeba ("PCI/ASPM: Configure L1 substate settings")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Vidya Sagar <vidyas@nvidia.com>
CC: stable@vger.kernel.org # v4.11+
CC: Rajat Jain <rajatja@google.com>
Every Port that supports the L1.2 substate advertises its Port
Common_Mode_Restore_Time, i.e., the time the Port requires to re-establish
common mode when exiting L1.2 (see PCIe r3.1, sec 7.33.2).
Per sec 5.5.3.3.1, when exiting L1.2, the Downstream Port (the device at
the upstream end of the link) must send TS1 training sequences for at least
T(COMMONMODE) after it detects electrical idle exit on the Link. We want
this to be long enough for both ends of the Link, so we should set it to
the maximum of the Port Common_Mode_Restore_Time for the upstream and
downstream components on the Link.
Previously we only looked at the Port Common_Mode_Restore_Time of the
upstream device, so if the downstream device required more time, we didn't
program the upstream device's T(COMMONMODE) correctly.
Fixes: f1f0366dd6 ("PCI/ASPM: Calculate and save the L1.2 timing parameters")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Vidya Sagar <vidyas@nvidia.com>
Acked-by: Rajat Jain <rajatja@google.com>
CC: stable@vger.kernel.org # v4.11+
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Several function prototypes for the set/get functions defined by
module_param_call() have a slightly wrong argument types. This fixes
those in an effort to clean up the calls when running under type-enforced
compiler instrumentation for CFI. This is the result of running the
following semantic patch:
@match_module_param_call_function@
declarer name module_param_call;
identifier _name, _set_func, _get_func;
expression _arg, _mode;
@@
module_param_call(_name, _set_func, _get_func, _arg, _mode);
@fix_set_prototype
depends on match_module_param_call_function@
identifier match_module_param_call_function._set_func;
identifier _val, _param;
type _val_type, _param_type;
@@
int _set_func(
-_val_type _val
+const char * _val
,
-_param_type _param
+const struct kernel_param * _param
) { ... }
@fix_get_prototype
depends on match_module_param_call_function@
identifier match_module_param_call_function._get_func;
identifier _val, _param;
type _val_type, _param_type;
@@
int _get_func(
-_val_type _val
+char * _val
,
-_param_type _param
+const struct kernel_param * _param
) { ... }
Two additional by-hand changes are included for places where the above
Coccinelle script didn't notice them:
drivers/platform/x86/thinkpad_acpi.c
fs/lockd/svc.c
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Even though it is unconventional, some PCIe host implementations omit the
root ports entirely, and simply consist of a host bridge (which is not
modeled as a device in the PCI hierarchy) and a link.
When the downstream device is an endpoint, our current code does not seem
to mind this unusual configuration. However, when PCIe switches are
involved, the ASPM code assumes that any downstream switch port has a
parent, and blindly dereferences the bus->parent->self field of the pci_dev
struct to chain the downstream link state to the link state of the root
port. Given that the root port is missing, the link is not modeled at all,
and nor is the link state, and attempting to access it results in a NULL
pointer dereference and a crash.
Avoid this by allowing the link state chain to terminate at the downstream
port if no root port exists.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
We call pcie_aspm_exit_link_state() when we remove a device. If the device
is the last PCIe function to be removed below a bridge and the bridge has
an ASPM link_state struct, we disable ASPM on the link. Disabling ASPM
requires link->downstream (used in pcie_config_aspm_link()).
We previously set link->downstream in pcie_aspm_cap_init(), but only if the
device was not blacklisted. Removing the blacklisted device caused a NULL
pointer dereference in the pcie_aspm_exit_link_state() ->
pcie_config_aspm_link() path:
# echo 1 > /sys/bus/pci/devices/0000\:0b\:00.0/remove
...
BUG: unable to handle kernel NULL pointer dereference at 0000000000000080
IP: pcie_config_aspm_link+0x5d/0x2b0
Call Trace:
pcie_aspm_exit_link_state+0x75/0x130
pci_stop_bus_device+0xa4/0xb0
pci_stop_and_remove_bus_device_locked+0x1a/0x30
remove_store+0x50/0x70
dev_attr_store+0x18/0x30
sysfs_kf_write+0x44/0x60
kernfs_fop_write+0x10e/0x190
__vfs_write+0x28/0x110
? rcu_read_lock_sched_held+0x5d/0x80
? rcu_sync_lockdep_assert+0x2c/0x60
? __sb_start_write+0x173/0x1a0
? vfs_write+0xb3/0x180
vfs_write+0xc4/0x180
SyS_write+0x49/0xa0
do_syscall_64+0xa6/0x1c0
entry_SYSCALL64_slow_path+0x25/0x25
---[ end trace bd187ee0267df5d9 ]---
To avoid this, set link->downstream in alloc_pcie_link_state(), so every
pcie_link_state structure has a valid link->downstream pointer.
[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rajat Jain <rajatja@google.com>
CC: stable@vger.kernel.org
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=4Owc
-----END PGP SIGNATURE-----
Merge tag 'pci-v4.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
- add ASPM L1 substate support
- enable PCIe Extended Tags when supported
- configure PCIe MPS settings on iProc, Versatile, X-Gene, and Xilinx
- increase VPD access timeout
- add ACS quirks for Intel Union Point, Qualcomm QDF2400 and QDF2432
- use new pci_irq_alloc_vectors() in more drivers
- fix MSI affinity memory leak
- remove unused MSI interfaces and update documentation
- remove unused AER .link_reset() callback
- avoid pci_lock / p->pi_lock deadlock seen with perf
- serialize sysfs enable/disable num_vfs operations
- move DesignWare IP from drivers/pci/host/ to drivers/pci/dwc/ and
refactor so we can support both hosts and endpoints
- add DT ECAM-like support for HiSilicon Hip06/Hip07 controllers
- add Rockchip system power management support
- add Thunder-X cn81xx and cn83xx support
- add Exynos 5440 PCIe PHY support
* tag 'pci-v4.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (93 commits)
PCI: dwc: Remove dependency of designware on CONFIG_PCI
PCI: dwc: Add CONFIG_PCIE_DW_HOST to enable PCI dwc host
PCI: dwc: Split pcie-designware.c into host and core files
PCI: dwc: designware: Fix style errors in pcie-designware.c
PCI: dwc: designware: Parse "num-lanes" property in dw_pcie_setup_rc()
PCI: dwc: all: Split struct pcie_port into host-only and core structures
PCI: dwc: designware: Get device pointer at the start of dw_pcie_host_init()
PCI: dwc: all: Rename cfg_read/cfg_write to read/write
PCI: dwc: all: Use platform_set_drvdata() to save private data
PCI: dwc: designware: Move register defines to designware header file
PCI: dwc: Use PTR_ERR_OR_ZERO to simplify code
PCI: dra7xx: Group PHY API invocations
PCI: dra7xx: Enable MSI and legacy interrupts simultaneously
PCI: dra7xx: Add support to force RC to work in GEN1 mode
PCI: dra7xx: Simplify probe code with devm_gpiod_get_optional()
PCI: Move DesignWare IP support to new drivers/pci/dwc/ directory
PCI: exynos: Support the PHY generic framework
Documentation: binding: Modify the exynos5440 PCIe binding
phy: phy-exynos-pcie: Add support for Exynos PCIe PHY
Documentation: samsung-phy: Add exynos-pcie-phy binding
...
Since the exit latencies for L1 substates are not advertised by a device,
it is not clear in spec how to do a L1 substate exit latency check. We
assume that the L1 exit latencies advertised by a device include L1
substate latencies (and hence do not do any check). If that is not true,
we should do some sort of check here.
(I'm not clear about what that check should like currently. I'd be glad to
take up any suggestions).
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Configure the L1 substate settings on the upstream and downstream devices,
while taking care of the rules dictated by the PCIe spec.
[bhelgaas: drop "inline"]
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The PCIe spec (r3.1, sec 7.33) says the L1 PM Substates Capability may be
implemented only in function 0.
Read the L1 substate capability structures of upstream and downstream
components of the link and set it up in the device structure.
[bhelgaas: add specific spec reference]
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Add support for ASPM L1 substates. For details about L1 substates, see the
PCIe r3.1 spec, which includes the ECN below in secs 5.5 and 7.33.
Add macros for the 4 new L1 substates, and add a new ASPM "POWER_SUPERSAVE"
policy that can be used to enable L1 substates on a system if desired. The
new policy is in a sense, a superset of the existing POWERSAVE policy. The
4 policies are now:
DEFAULT: Reads and uses whatever ASPM states BIOS enabled
PERFORMANCE: Everything except L0 disabled.
POWERSAVE: L0s and L1 enabled (but not L1 substates)
POWER_SUPERSAVE: L0s + L1 + L1 substates also enabled
[bhelgaas: add PCIe r3.1 spec reference]
Link: https://pcisig.com/sites/default/files/specification_documents/ECN_L1_PM_Substates_with_CLKREQ_31_May_2013_Rev10a.pdf
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
In a struct pcie_link_state, link->root points to the pcie_link_state of
the root of the PCIe hierarchy. For the topmost link, this points to
itself (link->root = link). For others, we copy the pointer from the
parent (link->root = link->parent->root).
Previously we recognized that Root Ports originated PCIe hierarchies, but
we treated PCI/PCI-X to PCIe Bridges as being in the middle of the
hierarchy, and when we tried to copy the pointer from link->parent->root,
there was no parent, and we dereferenced a NULL pointer:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000090
IP: [<ffffffff9e424350>] pcie_aspm_init_link_state+0x170/0x820
Recognize that PCI/PCI-X to PCIe Bridges originate PCIe hierarchies just
like Root Ports do, so link->root for these devices should also point to
itself.
Fixes: 51ebfc92b7 ("PCI: Enumerate switches below PCI-to-PCIe bridges")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=193411
Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1022181
Tested-by: lists@ssl-mail.com
Tested-by: Jayachandran C. <jnair@caviumnetworks.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org # v4.2+
Some (defective) PCIe devices are not able to reliably do link retraining.
Check to see if ASPM is possible between link partners before configuring
common clocking, and doing the resulting link retraining. If ASPM is not
possible, there is no reason to risk losing access to a device due to an
unnecessary link retraining.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Use DEVICE_ATTR_RW for read-write attributes. This simplifies the source
code, improves readability, and reduces the chance of inconsistencies.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@rw@
declarer name DEVICE_ATTR;
identifier x,x_show,x_store;
@@
DEVICE_ATTR(x, \(0644\|S_IRUGO|S_IWUSR\), x_show, x_store);
@script:ocaml@
x << rw.x;
x_show << rw.x_show;
x_store << rw.x_store;
@@
if not (x^"_show" = x_show && x^"_store" = x_store)
then Coccilib.include_match false
@@
declarer name DEVICE_ATTR_RW;
identifier rw.x,rw.x_show,rw.x_store;
@@
- DEVICE_ATTR(x, \(0644\|S_IRUGO|S_IWUSR\), x_show, x_store);
+ DEVICE_ATTR_RW(x);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Without supporting clock PM capable, if we want to disable clkpm, we don't
need this extra check as it must already be zero for the enable argument.
And it's the same for enabling clkpm here. So let's remove this check.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
If CONFIG_PCIEASPM_DEBUG is set, then PCI devices have a link_state
attribute. Reading that attribute shows the state as a bit mask: 1
means L0S upstream, 2 means L0S downstream, and 4 means L1.
Oddly, writing to link_state is inconsistent and gets translated, leading
to mysterious results in which the value you store isn't comparable the
value you load back out.
Fix it by making link_state_store() match link_state_show().
[bhelgaas: Check "aspm_disabled" *before* validating input. When
"aspm_disabled" is set, this changes the error for invalid input from
-EINVAL to -EPERM.]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Update the Link Control Enable Clock Power Management bit the same
way we update the ASPM Control bits, with a single call of
pcie_capability_clear_and_set_word().
No functional change; this just makes both paths use the same style.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
We allocate pcie_link_state for the component at the upstream end of a
Link. Previously we did this by allocating pcie_link_state for Root Ports
and Downstream Ports. This works fine for the typical topology:
00:1c.0 Root Port [bridge to bus 02]
02:00.0 Upstream Port [bridge to bus 03]
03:00.0 Downstream Port [bridge to bus 04]
04:00.0 Endpoint or Switch Port
However, it is possible to have a Root Port connected to a Downstream Port
instead of an Upstream Port, as in Robert White's ATCA system:
00:1c.0 Root Port [bridge to bus 02]
02:00.0 Downstream Port [bridge to bus 03]
03:01.0 Downstream Port [bridge to bus 04]
04:00.0 Endpoint or Switch Port
In this topology, we wrongly allocated pcie_link_state for the 02:00.0
Downstream Port, which is actually the *downstream* end of a link. This
led to the following NULL pointer dereference when we tried to connect this
link into the tree of links starting at the 00:1c.0 Root Port:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000088
IP: [<ffffffff81550324>] pcie_aspm_init_link_state+0x744/0x850
Hardware name: Kontron B3001/B3001, BIOS 4.6.3 08/07/2012
Call Trace:
[<ffffffff8153b865>] pci_scan_slot+0xd5/0x120
[<ffffffff8153ca1d>] pci_scan_child_bus+0x2d/0xd0
...
Instead of relying on the component type to identify the upstream end of a
link, use the "dev->has_secondary_link" field.
This means it's now possible for an Upstream Port to have a link on its
secondary side, so alloc_pcie_link_state() needs to connect links
originating from both Upstream and Downstream Ports into the tree.
[bhelgaas: changelog, add comment]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=94361
Link: http://lkml.kernel.org/r/54EB81B2.4050904@pobox.com
Reported-by: Robert White <rwhite@pobox.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
We decide in alloc_pcie_link_state() whether to allocate a pcie_link_state
for a device. After that, it's sufficient to check pdev->link_state. We
don't need to check the PCIe port type again.
Remove the redundant PCIe port type checking.
[bhelgaas: changelog]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
After 387d37577f ("PCI: Don't clear ASPM bits when the FADT declares it's
unsupported"), the "force" parameter to __pci_disable_link_state() is
always "false".
Remove the "force" parameter and assume it's always false.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Communications with a hardware vendor confirm that the expected behaviour
on systems that set the FADT ASPM disable bit but which still grant full
PCIe control is for the OS to leave any BIOS configuration intact and
refuse to touch the ASPM bits. This mimics the behaviour of Windows.
Signed-off-by: Matthew Garrett <mjg59@coreos.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The functions link_state_store() and clk_ctl_store() had just subtracted
ASCII '0' from input which could lead to undesired results. Instead, use
Linux string functions to safely parse input.
[bhelgaas: check kstrtouint() return value]
Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
My philosophy is unused code is dead code. And dead code is subject to bit
rot and is a likely source of bugs. Use it or lose it.
This reverts part of 3e1b16002a ("ACPI/PCI: PCIe ASPM _OSC support
capabilities called when root bridge added"), removing this interface:
pcie_aspm_enabled()
[bhelgaas: split to separate patch]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Andrew Patterson <andrew.patterson@hp.com>
Fix whitespace, capitalization, and spelling errors. No functional change.
I know "busses" is not an error, but "buses" was more common, so I used it
consistently.
Signed-off-by: Marta Rybczynska <rybczynska@gmail.com> (pci_reset_bridge_secondary_bus())
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Some devices have hardware problems related to using ASPM. Drivers for
these devices use pci_disable_link_state() to prevent their device from
entering L0s or L1. But on platforms where the OS doesn't have permission
to manage ASPM, pci_disable_link_state() doesn't actually disable ASPM.
Windows has a similar mechanism ("PciASPMOptOut"), and when the OS doesn't
have control of ASPM, it doesn't actually disable ASPM either.
This patch just adds a warning in dmesg about the fact that
pci_disable_link_state() is doing nothing.
Reported-by: Emmanuel Grumbach <egrumbach@gmail.com>
Reference: https://lkml.kernel.org/r/CANUX_P3F5YhbZX3WGU-j1AGpbXb_T9Bis2ErhvKkFMtDvzatVQ@mail.gmail.com
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=57331
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Host bridge hotplug
- Major overhaul of ACPI host bridge add/start (Rafael Wysocki, Yinghai Lu)
- Major overhaul of PCI/ACPI binding (Rafael Wysocki, Yinghai Lu)
- Split out ACPI host bridge and ACPI PCI device hotplug (Yinghai Lu)
- Stop caching _PRT and make independent of bus numbers (Yinghai Lu)
PCI device hotplug
- Clean up cpqphp dead code (Sasha Levin)
- Disable ARI unless device and upstream bridge support it (Yijing Wang)
- Initialize all hot-added devices (not functions 0-7) (Yijing Wang)
Power management
- Don't touch ASPM if disabled (Joe Lawrence)
- Fix ASPM link state management (Myron Stowe)
Miscellaneous
- Fix PCI_EXP_FLAGS accessor (Alex Williamson)
- Disable Bus Master in pci_device_shutdown (Konstantin Khlebnikov)
- Document hotplug resource and MPS parameters (Yijing Wang)
- Add accessor for PCIe capabilities (Myron Stowe)
- Drop pciehp suspend/resume messages (Paul Bolle)
- Make pci_slot built-in only (not a module) (Jiang Liu)
- Remove unused PCI/ACPI bind ops (Jiang Liu)
- Removed used pci_root_bus (Bjorn Helgaas)
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=ER3b
-----END PGP SIGNATURE-----
Merge tag 'pci-v3.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI changes from Bjorn Helgaas:
"Host bridge hotplug
- Major overhaul of ACPI host bridge add/start (Rafael Wysocki, Yinghai Lu)
- Major overhaul of PCI/ACPI binding (Rafael Wysocki, Yinghai Lu)
- Split out ACPI host bridge and ACPI PCI device hotplug (Yinghai Lu)
- Stop caching _PRT and make independent of bus numbers (Yinghai Lu)
PCI device hotplug
- Clean up cpqphp dead code (Sasha Levin)
- Disable ARI unless device and upstream bridge support it (Yijing Wang)
- Initialize all hot-added devices (not functions 0-7) (Yijing Wang)
Power management
- Don't touch ASPM if disabled (Joe Lawrence)
- Fix ASPM link state management (Myron Stowe)
Miscellaneous
- Fix PCI_EXP_FLAGS accessor (Alex Williamson)
- Disable Bus Master in pci_device_shutdown (Konstantin Khlebnikov)
- Document hotplug resource and MPS parameters (Yijing Wang)
- Add accessor for PCIe capabilities (Myron Stowe)
- Drop pciehp suspend/resume messages (Paul Bolle)
- Make pci_slot built-in only (not a module) (Jiang Liu)
- Remove unused PCI/ACPI bind ops (Jiang Liu)
- Removed used pci_root_bus (Bjorn Helgaas)"
* tag 'pci-v3.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (51 commits)
PCI/ACPI: Don't cache _PRT, and don't associate them with bus numbers
PCI: Fix PCI Express Capability accessors for PCI_EXP_FLAGS
ACPI / PCI: Make pci_slot built-in only, not a module
PCI/PM: Clear state_saved during suspend
PCI: Use atomic_inc_return() rather than atomic_add_return()
PCI: Catch attempts to disable already-disabled devices
PCI: Disable Bus Master unconditionally in pci_device_shutdown()
PCI: acpiphp: Remove dead code for PCI host bridge hotplug
PCI: acpiphp: Create companion ACPI devices before creating PCI devices
PCI: Remove unused "rc" in virtfn_add_bus()
PCI: pciehp: Drop suspend/resume ENTRY messages
PCI/ASPM: Don't touch ASPM if forcibly disabled
PCI/ASPM: Deallocate upstream link state even if device is not PCIe
PCI: Document MPS parameters pci=pcie_bus_safe, pci=pcie_bus_perf, etc
PCI: Document hpiosize= and hpmemsize= resource reservation parameters
PCI: Use PCI Express Capability accessor
PCI: Introduce accessor to retrieve PCIe Capabilities Register
PCI: Put pci_dev in device tree as early as possible
PCI: Skip attaching driver in device_add()
PCI: acpiphp: Keep driver loaded even if no slots found
...
Don't allocate and track PCIe ASPM state when "pcie_aspm=off" is specified
on the kernel command line.
Based-on-patch-from: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: David Bulkow <david.bulkow@stratus.com>
Acked-by: Myron Stowe <myron.stowe@redhat.com>
