Atomic writes support may not always be possible when stacking devices
which support atomic writes. Such as case is a different atomic write
boundary between stacked devices (which is not supported).
In the case that atomic writes cannot supported, the top device queue HW
limits are set to 0.
However, in blk_stack_atomic_writes_limits(), we detect that we are
stacking the first bottom device by checking the top device
atomic_write_hw_max value == 0. This get confused with the case of atomic
writes not supported, above.
Make the distinction between stacking the first bottom device and no
atomics supported by initializing stacked device atomic_write_hw_max =
UINT_MAX and checking that for stacking the first bottom device.
Fixes: d7f36dc446 ("block: Support atomic writes limits for stacked devices")
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In commit 63d092d1c1 ("block: use chunk_sectors when evaluating stacked
atomic write limits"), it was missed to use a chunk sectors limit check
in blk_stack_atomic_writes_boundary_head(), so update that function to
do the proper check.
Fixes: 63d092d1c1 ("block: use chunk_sectors when evaluating stacked atomic write limits")
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
On the TUXEDO InfinityBook S Gen8, a Samsung 990 Evo NVMe leads to
a high power consumption in s2idle sleep (3.5 watts).
This patch applies 'Force No Simple Suspend' quirk to achieve a sleep with
a lower power consumption, typically around 1 watts.
Signed-off-by: Georg Gottleuber <ggo@tuxedocomputers.com>
Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
Cc: stable@vger.kernel.org
Signed-off-by: Keith Busch <kbusch@kernel.org>
Make acpi_nondev_subnode_extract() follow the usual code flow pattern
in which failure is handled at the point where it is detected.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
In certain circumstances, the ACPI handle of a data-only node may be
NULL, in which case it does not make sense to attempt to attach that
node to an ACPI namespace object, so update the code to avoid attempts
to do so.
This prevents confusing and unuseful error messages from being printed.
Also document the fact that the ACPI handle of a data-only node may be
NULL and when that happens in a code comment. In addition, make
acpi_add_nondev_subnodes() print a diagnostic message for each data-only
node with an unknown ACPI namespace scope.
Fixes: 1d52f10917 ("ACPI: property: Tie data nodes to acpi handles")
Cc: 6.0+ <stable@vger.kernel.org> # 6.0+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
In some places in the ACPI device properties handling code, it is
unclear why the code is what it is. Some assumptions are not documented
and some pieces of code are based on knowledge that is not mentioned
anywhere.
Add code comments explaining these things.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Data-only subnode links following the ACPI data subnode GUID in a _DSD
package are expected to point to named objects returning _DSD-equivalent
packages. If a reference to such an object is used in the target field
of any of those links, that object will be evaluated in place (as a
named object) and its return data will be embedded in the outer _DSD
package.
For this reason, it is not expected to see a subnode link with the
target field containing a local reference (that would mean pointing
to a device or another object that cannot be evaluated in place and
therefore cannot return a _DSD-equivalent package).
Accordingly, simplify the code parsing data-only subnode links to
simply print a message when it encounters a local reference in the
target field of one of those links.
Moreover, since acpi_nondev_subnode_data_ok() would only have one
caller after the change above, fold it into that caller.
Link: https://lore.kernel.org/linux-acpi/CAJZ5v0jVeSrDO6hrZhKgRZrH=FpGD4vNUjFD8hV9WwN9TLHjzQ@mail.gmail.com/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
The ACPI handle passed to acpi_extract_properties() as the first
argument represents the ACPI namespace scope in which to look for
objects returning buffers associated with buffer properties.
For _DSD objects located immediately under ACPI devices, this handle is
the same as the handle of the device object holding the _DSD, but for
data-only subnodes it is not so.
First of all, data-only subnodes are represented by objects that
cannot hold other objects in their scopes (like control methods).
Therefore a data-only subnode handle cannot be used for completing
relative pathname segments, so the current code in
in acpi_nondev_subnode_extract() passing a data-only subnode handle
to acpi_extract_properties() is invalid.
Moreover, a data-only subnode of device A may be represented by an
object located in the scope of device B (which kind of makes sense,
for instance, if A is a B's child). In that case, the scope in
question would be the one of device B. In other words, the scope
mentioned above is the same as the scope used for subnode object
lookup in acpi_nondev_subnode_extract().
Accordingly, rearrange that function to use the same scope for the
extraction of properties and subnode object lookup.
Fixes: 103e10c69c ("ACPI: property: Add support for parsing buffer property UUID")
Cc: 6.0+ <stable@vger.kernel.org> # 6.0+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Document an optional interrupt found in some controllers of BQ27xxx
series. The pin to which the interrupt is connected is called SOC_INT or
GPOUT.
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Add documentation on how to resolve conflicts between CXL Fixed Memory
Windows, Platform Low Memory Holes, intermediate Switch and Endpoint
Decoders.
[dj]: Fixed inconsistent spacing after '.'
[dj]: Fixed subject line from Alison.
[dj]: Removed '::' before table from Bagas.
Reviewed-by: Gregory Price <gourry@gourry.net>
Signed-off-by: Fabio M. De Francesco <fabio.m.de.francesco@linux.intel.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
The parameter max_hw_wzeroes_unmap_sectors in queue_limits should be
equal to max_write_zeroes_sectors if it is set to a non-zero value.
However, the stacked md drivers call md_init_stacking_limits() to
initialize this parameter to UINT_MAX but only adjust
max_write_zeroes_sectors when setting limits. Therefore, this
discrepancy triggers a value check failure in blk_validate_limits().
$ modprobe scsi_debug num_parts=2 dev_size_mb=8 lbprz=1 lbpws=1
$ mdadm --create /dev/md0 --level=0 --raid-device=2 /dev/sda1 /dev/sda2
mdadm: Defaulting to version 1.2 metadata
mdadm: RUN_ARRAY failed: Invalid argument
Fix this failure by explicitly setting max_hw_wzeroes_unmap_sectors to
max_write_zeroes_sectors. Since the linear and raid0 drivers support
write zeroes, so they can support unmap write zeroes operation if all of
the backend devices support it. However, the raid1/10/5 drivers don't
support write zeroes, so we have to set it to zero.
Fixes: 0c40d7cb5e ("block: introduce max_{hw|user}_wzeroes_unmap_sectors to queue limits")
Reported-by: John Garry <john.g.garry@oracle.com>
Closes: https://lore.kernel.org/linux-block/803a2183-a0bb-4b7a-92f1-afc5097630d2@oracle.com/
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Tested-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Li Nan <linan122@huawei.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/linux-raid/20250910111107.3247530-2-yi.zhang@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Recursing into pci_bus_release_bridge_resources() should not alter rel_type
because it makes no sense to change the release type within the recursion
call chain. A literal "whole_subtree" is passed into the recursion instead
of "rel_type" parameter which is misleading as the release type should
remain the same throughout the entire operation.
This is not a correctness issue because of the preceding if () that only
allows the recursion to happen if rel_type is "whole_subtree". Still,
replace the non-intuitive parameter with direct passing of "rel_type".
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-25-ilpo.jarvinen@linux.intel.com
pci_bus_release_bridge_resources() takes type, which is converted into a
bridge window resource in pci_bridge_release_resources().
Find out the correct bridge window for resource whose assignment failed.
Pass that bridge window to pci_bus_release_bridge_resources() instead of
passing the type. When recursing to subordinate, check which bridge windows
have to be released and recurse for each.
For now, use pbus_select_window_for_type() instead of pbus_select_window()
because non-bridge window resources still have their flags reset which
destroys the type information from the struct resource. The struct
pci_dev_resource holds a copy of the flags which are used instead.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-24-ilpo.jarvinen@linux.intel.com
pci_bridge_release_resources() contains a resource type hack to work
around the unsuitable __pci_setup_bridge() interface. Extract the
switch statement that picks the correct bridge window setup function
from pci_claim_bridge_resource() into pci_setup_one_bridge_window() and
use it also in pci_bridge_release_resources().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-23-ilpo.jarvinen@linux.intel.com
pci_bus_distribute_available_resources() and
pci_bridge_distribute_available_resources() retain bridge window resources
and related data needed for distributing the available window in
independent variables for io, memory, and prefetchable memory windows. The
code is essentially the same for all of them and therefore repeated three
times with different variable names.
Refactor pci_bus_distribute_available_resources() to take an array. This
is complicated slightly by the function taking advantage of passing the
struct as value, which cannot be done for arrays in C. Therefore, copy the
data into a local array in the stack in the first loop.
Variable names are (hopefully) improved slightly as well.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-21-ilpo.jarvinen@linux.intel.com
__pci_bus_size_bridges() goes to great lengths of helping pbus_size_mem()
in which types it should put into a particular bridge window, requiring
passing up to three resource type into pbus_size_mem().
Instead of having complex logic in __pci_bus_size_bridges() and a
non-straightforward interface between those functions, use
pbus_select_window_for_type() and pbus_select_window() to find the correct
bridge window and compare if the resources belong to that window.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-20-ilpo.jarvinen@linux.intel.com
pbus_upstream_space_available() figures out the upstream bridge window
resources on its own. Migrate it to use pbus_select_window().
Note: pbus_select_window() -> pbus_select_window_for_type() calls
find_bus_resource_of_type() for root bus, which does not do parent check
similar to what pbus_upstream_space_available() did earlier, but the
difference does not matter because pbus_upstream_space_available() itself
stops when it encounters the root bus.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-19-ilpo.jarvinen@linux.intel.com
Prior to a BAR resize, __resource_resize_store() loops through the normal
resources of the PCI device and releases those that match to the flags of
the BAR to be resized. This is necessary to allow resizing also the
upstream bridge window as only childless bridge windows can be resized.
While the flags check (mostly) works (if corner cases are ignored), the
more straightforward way is to check if the resources share the bridge
window. Change __resource_resize_store() to do the check using
pbus_select_window().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-16-ilpo.jarvinen@linux.intel.com
BAR resizing calls to pci_reassign_bridge_resources(), which attempts to
release any upstream bridge window to allow them to accommodate the new BAR
size. The release can only be performed if there are no other child
resources for the bridge window. Previously the code continued silently
when other child resources were detected.
Add pci_warn() to inform user that a bridge window could not be released
because of child resources. As a small bridge window is often the reason
why BAR resize fails, this warning will help to pinpoint to the cause.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-15-ilpo.jarvinen@linux.intel.com
pci_reassign_bridge_resources() walks upwards in the PCI bus hierarchy,
locates the relevant bridge window on each level using flags check, and
attempts to release the bridge window. The flags-based check is fragile due
to various fallbacks in the bridge window selection logic. As such, the
algorithm might not locate the correct bridge window.
Refactor pci_reassign_bridge_resources() to determine the correct bridge
window using pbus_select_window(), which contains logic to handle all
fallback cases correctly. Change function prefix to pbus as it now inputs
struct bus and resource for which to locate the bridge window.
The main purpose is to make bridge window selection logic consistent across
the entire PCI core (one step at a time). While this technically also fixes
the commit 8bb705e3e7 ("PCI: Add pci_resize_resource() for resizing
BARs") making the bridge window walk algorithm more robust, the normal
setup having a 64-bit resizable BAR underneath bridge(s) with 64-bit
prefetchable windows does not need to use any fallbacks. As such, the
practical impact is low (requiring BAR resize use case and a non-typical
bridge device).
The way to detect if unrelated resource failed again is left to use the
type based approximation which should not behave worse than before.
Fixes: 8bb705e3e7 ("PCI: Add pci_resize_resource() for resizing BARs")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-14-ilpo.jarvinen@linux.intel.com
Various places in the PCI core code independently decide into which bridge
window a child resource should be placed. It is hard to see whether these
decisions always end up in agreement, especially in the corner cases, and
in some places it requires complex logic to pass multiple resource types
and/or bridge windows around.
Add pbus_select_window() and pbus_select_window_for_type() for cases where
the former cannot be used so that eventually the same helper can be used to
select the bridge window everywhere. Using the same function ensures the
selected bridge window remains always the same and it can be easily
recalculated in-situ allowing simplifying the interfaces between internal
functions in upcoming changes.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-13-ilpo.jarvinen@linux.intel.com
include/linux/pci.h provides PCI_BRIDGE_{IO,MEM,PREF_MEM}_WINDOW defines,
however, they're based on the resource array indexing in the pci_dev
struct. The struct pci_bus also has pointers to those same resources but
they start from zeroth index.
Add PCI_BUS_BRIDGE_{IO,MEM,PREF_MEM}_WINDOW defines to get rid of literal
indexing.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-12-ilpo.jarvinen@linux.intel.com
When a bridge window is found unused or fails to assign, the flags of the
associated resource are cleared. Clearing flags is problematic as it also
removes the type information of the resource which is needed later.
Thus, always preserve the bridge window type flags and use IORESOURCE_UNSET
and IORESOURCE_DISABLED to indicate the status of the bridge window. Also,
when initializing resources, make sure all valid bridge windows do get
their type flags set.
Change various places that relied on resource flags being cleared to check
for IORESOURCE_UNSET and IORESOURCE_DISABLED to allow bridge window
resource to retain their type flags. Add pdev_resource_assignable() and
pdev_resource_should_fit() helpers to filter out disabled bridge windows
during resource fitting; the latter combines more common checks into the
helper.
When reading the bridge windows from the registers, instead of leaving the
resource flags cleared for bridge windows that are not enabled, always
set up the flags and set IORESOURCE_UNSET | IORESOURCE_DISABLED as needed.
When resource fitting or assignment fails for a bridge window resource, or
the bridge window is not needed, mark the resource with IORESOURCE_UNSET or
IORESOURCE_DISABLED, respectively.
Use dummy zero resource in resource_show() for backwards compatibility as
lspci will otherwise misrepresent disabled bridge windows.
This change fixes an issue which highlights the importance of keeping the
resource type flags intact:
At the end of __assign_resources_sorted(), reset_resource() is called,
previously clearing the flags. Later, pci_prepare_next_assign_round()
attempted to release bridge resources using
pci_bus_release_bridge_resources() that calls into
pci_bridge_release_resources() that assumes type flags are still present.
As type flags were cleared, IORESOURCE_MEM_64 was not set leading to
resources under an incorrect bridge window to be released (idx = 1
instead of idx = 2). While the assignments performed later covered this
problem so that the wrongly released resources got assigned in the end,
it was still causing extra release+assign pairs.
There are other reasons why the resource flags should be retained in
upcoming changes too.
Removing the flag reset for non-bridge window resource is left as future
work, in part because it has a much higher regression potential due to
pci_enable_resources() that will start to work also for those resources
then and due to what endpoint drivers might assume about resources.
Despite the Fixes tag, backporting this (at least any time soon) is highly
discouraged. The issue fixed is borderline cosmetic as the later
assignments normally cover the problem entirely. Also there might be
non-obvious dependencies.
Fixes: 5b28541552 ("PCI: Restrict 64-bit prefetchable bridge windows to 64-bit resources")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-11-ilpo.jarvinen@linux.intel.com
A normal PCI bridge has multiple bridge windows and not all of them are
always required by devices underneath the bridge. If a Root Port or bridge
does not have a device underneath, no bridge windows get assigned. Yet,
pci_enable_resources() is set to fail indiscriminantly on any resource
assignment failure if the resource is not known to be optional.
In practice, the code in pci_enable_resources() is currently largely
dormant. The kernel sets resource flags to zero for any unused bridge
window and resets flags to zero in case of an resource assignment failure,
which short-circuits pci_enable_resources() because of this check:
if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
continue;
However, an upcoming change to resource flags will alter how bridge window
resource flags behave activating these long dormants checks in
pci_enable_resources().
While complex logic could be built to selectively enable a bridge only
under some conditions, a few versions of such logic were tried during
development of this change and none of them worked satisfactorily. Thus, I
just gave up and decided to enable any bridge regardless of the bridge
windows as there seems to be no clear benefit from not enabling it, but a
major downside as pcieport will not be probed for the bridge if it's not
enabled.
Therefore, change pci_enable_resources() to not check if bridge window
resources remain unassigned. Resource assignment failures are pretty noisy
already so there is no need to log that for bridge windows in
pci_enable_resources().
Ignoring bridge window failures hopefully prevents an obvious source of
regressions when the upcoming change that no longer clears resource flags
for bridge windows is enacted. I've hit this problem even during my own
testing on multiple occasions so I expect it to be a quite common problem.
This can always be revisited later if somebody thinks the enable check for
bridges is not strict enough, but expect a mind-boggling number of
regressions from such a change.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-10-ilpo.jarvinen@linux.intel.com
A few places in setup-bus.c call release_resource() directly and end up
duplicating functionality from pci_release_resource() such as parent check,
logging, and clearing the resource. Worse yet, the way the resource is
cleared is inconsistent between different sites.
Convert release_resource() calls into pci_release_resource() to remove code
duplication. This will also make the resource start, end, and flags
behavior consistent, i.e., start address is cleared, and only
IORESOURCE_UNSET is asserted for the resource.
While at it, eliminate the unnecessary initialization of idx variable in
pci_bridge_release_resources().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-9-ilpo.jarvinen@linux.intel.com
If clipping or claiming the bridge window fails, the bridge window is left
in a state that does not match the kernel's view on what the bridge window
is.
Disable the bridge window by writing the magic disable value into the Base
and Limit Registers if clipping or claiming failed. To detect if claiming
the resource was successful, add res->parent checks into the bridge setup
functions.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-8-ilpo.jarvinen@linux.intel.com
When the claim of a resource fails for the full range in
pci_claim_bridge_resource(), clipping the resource to a smaller size is
attempted. If clipping is successful, the new bridge window is programmed
and only as the last step the code attempts to claim the resource again.
The order of the last two steps is slightly illogical and inconsistent with
the assignment call chains.
If claiming the bridge window after clipping fails, the bridge window that
was set up is left in place.
Rework the logic such that the bridge window is claimed before calling the
relevant bridge setup function. This make the behavior consistent with
resource fitting call chains that always assign the bridge window before
programming it.
If claiming the bridge window fails, the clipped bridge window is no longer
set up but pci_claim_bridge_resource() returns without writing the bridge
window at all.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-7-ilpo.jarvinen@linux.intel.com
pci-legacy.c under MIPS has a copy of pci_enable_resources() named as
pcibios_enable_resources(). Having own copy of same functionality could
lead to inconsistencies in behavior, especially now as
pci_enable_resources() and the bridge window resource flags behavior are
going to be altered by upcoming changes.
The check for !r->start && r->end is already covered by the more generic
checks done in pci_enable_resources().
Call pci_enable_resources() from MIPS's pcibios_enable_device() and remove
pcibios_enable_resources().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: https://patch.msgid.link/20250829131113.36754-4-ilpo.jarvinen@linux.intel.com
Under arch/sparc/ there are multiple copies of pcibios_enable_device() but
none of those seem to do anything extra beyond what pci_enable_resources()
is supposed to do. These functions could lead to inconsistencies in
behavior, especially now as pci_enable_resources() and the bridge window
resource flags behavior are going to be altered by upcoming changes.
Remove all pcibios_enable_device() from arch/sparc/ so that PCI core can
simply call into pci_enable_resources() instead using its __weak version
of pcibios_enable_device().
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-3-ilpo.jarvinen@linux.intel.com
m68k has a resource enable (check) loop in its pcibios_enable_device()
which for some reason differs from pci_enable_resources(). This could lead
to inconsistencies in behavior, especially now as pci_enable_resources()
and the bridge window resource flags behavior are going to be altered by
upcoming changes.
The check for !r->start && r->end is already covered by the more generic
checks done in pci_enable_resources().
The entire pcibios_enable_device() suspiciously looks copy-paste from some
other arch as also indicated by the preceding comment. However, it also
enables PCI_COMMAND_IO | PCI_COMMAND_MEMORY always for bridges. It is not
clear why that is being done as the commit e93a6bbeb5 ("m68k: common PCI
support definitions and code") introducing this code states "Nothing
specific to any PCI implementation in any m68k class CPU hardware yet".
Replace the resource enable loop with a call to pci_enable_resources() and
adjust the Command Register afterwards as it's unclear if that is necessary
or not so keep it for now.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250829131113.36754-2-ilpo.jarvinen@linux.intel.com
Since 96336ec702 ("PCI: Perform reset_resource() and build fail list in
sync") the failed list is always built and returned to let the caller
decide what to do with the failures. The caller may want to retry resource
fitting and assignment and before that can happen, the resources should be
restored to their original state (a reset effectively clears the struct
resource), which requires returning them to the failed list so the original
state remains stored in the associated struct pci_dev_resource.
Resource resizing is different from the ordinary resource fitting and
assignment in that it only considers part of the resources. This means
failures for other resource types are not relevant at all and should be
ignored. As resize doesn't unassign such unrelated resources, those
resources ending up in the failed list implies assignment of that
resource must have failed before resize too. The check in
pci_reassign_bridge_resources() to decide if the whole assignment is
successful, however, is based on list emptiness which will cause false
negatives when the failed list has resources with an unrelated type.
If the failed list is not empty, call pci_required_resource_failed() and
extend it to be able to filter on specific resource types too (if
provided).
Calling pci_required_resource_failed() at this point is slightly
problematic because the resource itself is reset when the failed list
is constructed in __assign_resources_sorted(). As a result,
pci_resource_is_optional() does not have access to the original
resource flags. This could be worked around by restoring and
re-resetting the resource around the call to pci_resource_is_optional(),
however, it shouldn't cause issue as resource resizing is meant for
64-bit prefetchable resources according to Christian König (see the
Link which unfortunately doesn't point directly to Christian's reply
because lore didn't store that email at all).
Fixes: 96336ec702 ("PCI: Perform reset_resource() and build fail list in sync")
Link: https://lore.kernel.org/all/c5d1b5d8-8669-5572-75a7-0b480f581ac1@linux.intel.com/
Reported-by: D Scott Phillips <scott@os.amperecomputing.com>
Closes: https://lore.kernel.org/all/86plf0lgit.fsf@scott-ph-mail.amperecomputing.com/
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: D Scott Phillips <scott@os.amperecomputing.com>
Reviewed-by: D Scott Phillips <scott@os.amperecomputing.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org # v6.15+
Link: https://patch.msgid.link/20250822123359.16305-4-ilpo.jarvinen@linux.intel.com
pdev_sort_resources() uses pdev_resources_assignable() helper to decide if
device's resources cannot be assigned, so it ignores class 0
(PCI_CLASS_NOT_DEFINED) devices. pbus_size_mem(), on the other hand, does
not do the same check. This could lead into a situation where a resource
ends up on realloc_head list but is not on the head list, which in turn
prevents emptying the resource from the realloc_head list in
__assign_resources_sorted().
A non-empty realloc_head is unacceptable because it triggers an internal
sanity check as shown in this log with a device that has class 0
(PCI_CLASS_NOT_DEFINED):
pci 0001:01:00.0: [144d:a5a5] type 00 class 0x000000 PCIe Endpoint
pci 0001:01:00.0: BAR 0 [mem 0x00000000-0x000fffff 64bit]
pci 0001:01:00.0: ROM [mem 0x00000000-0x0000ffff pref]
pcieport 0001:00:00.0: bridge window [mem 0x00100000-0x001fffff] to [bus 01-ff] add_size 100000 add_align 100000
pcieport 0001:00:00.0: bridge window [mem 0x40000000-0x401fffff]: assigned
------------[ cut here ]------------
kernel BUG at drivers/pci/setup-bus.c:2532!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
...
Call trace:
pci_assign_unassigned_bus_resources+0x110/0x114 (P)
pci_rescan_bus+0x28/0x48
Use pdev_resources_assignable() also within pbus_size_mem() to skip
processing of non-assignable resources which removes the disparity in
between what resources pdev_sort_resources() and pbus_size_mem() consider.
As non-assignable resources are no longer processed, they are not added to
the realloc_head list, thus the sanity check no longer triggers.
This disparity problem is very old but only now became apparent after
2499f53484 ("PCI: Rework optional resource handling") that made the ROM
resources optional when calculating bridge window sizes which required
adding the resource to the realloc_head list. Previously, bridge windows
were just sized larger than necessary.
Fixes: 2499f53484 ("PCI: Rework optional resource handling")
Reported-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Closes: https://lore.kernel.org/all/5f103643-5e1c-43c6-b8fe-9617d3b5447c@linaro.org/
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v6.15+
Link: https://patch.msgid.link/20250822123359.16305-3-ilpo.jarvinen@linux.intel.com
Currently, LKMM docs are not included in any of kernel documentation
books.
Commit e40573a43d ("docs: put atomic*.txt and memory-barriers.txt
into the core-api book") covered plain-text docs under Documentation/
by using the "include::" directive along with the ":literal:" option.
As LKMM docs are not under Documentation/, the same approach would not
work due to the directive's restriction.
As a matter of fact, kernel documentation has an extended directive
by the name of "kernel-include::", which loosens such restriction and
accepts any files under the kernel source tree.
Rather than moving LKMM docs around, use the latter and pull them into
the dev-tools book next to KCSAN.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <7ce84a93-5cbc-420e-894a-06a0372c52ab@gmail.com>
John Garry
Georg Gottleuber
Rafael J. Wysocki
Svyatoslav Ryhel
Vladimir Zapolskiy
Loic Poulain
Wenmeng Liu
Fabio M. De Francesco
Zhang Yi
Ilpo Järvinen
Akira Yokosawa
Thomas Zimmermann