linux.git/drivers/base, branch v6.1.92

driver core: Introduce device_link_wait_removal()

2024-04-10T14:28:32+00:00

commit 0462c56c290a99a7f03e817ae5b843116dfb575c upstream.

The commit 80dd33cf72d1 ("drivers: base: Fix device link removal")
introduces a workqueue to release the consumer and supplier devices used
in the devlink.
In the job queued, devices are release and in turn, when all the
references to these devices are dropped, the release function of the
device itself is called.

Nothing is present to provide some synchronisation with this workqueue
in order to ensure that all ongoing releasing operations are done and
so, some other operations can be started safely.

For instance, in the following sequence:
  1) of_platform_depopulate()
  2) of_overlay_remove()

During the step 1, devices are released and related devlinks are removed
(jobs pushed in the workqueue).
During the step 2, OF nodes are destroyed but, without any
synchronisation with devlink removal jobs, of_overlay_remove() can raise
warnings related to missing of_node_put():
  ERROR: memory leak, expected refcount 1 instead of 2

Indeed, the missing of_node_put() call is going to be done, too late,
from the workqueue job execution.

Introduce device_link_wait_removal() to offer a way to synchronize
operations waiting for the end of devlink removals (i.e. end of
workqueue jobs).
Also, as a flushing operation is done on the workqueue, the workqueue
used is moved from a system-wide workqueue to a local one.

Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina 
Tested-by: Luca Ceresoli 
Reviewed-by: Nuno Sa 
Reviewed-by: Saravana Kannan 
Acked-by: Greg Kroah-Hartman 
Link: https://lore.kernel.org/r/20240325152140.198219-2-herve.codina@bootlin.com
Signed-off-by: Rob Herring 
Signed-off-by: Greg Kroah-Hartman

PM: sleep: wakeirq: fix wake irq warning in system suspend

2024-04-03T13:19:30+00:00

[ Upstream commit e7a7681c859643f3f2476b2a28a494877fd89442 ]

When driver uses pm_runtime_force_suspend() as the system suspend callback
function and registers the wake irq with reverse enable ordering, the wake
irq will be re-enabled when entering system suspend, triggering an
'Unbalanced enable for IRQ xxx' warning. In this scenario, the call
sequence during system suspend is as follows:
  suspend_devices_and_enter()
    -> dpm_suspend_start()
      -> dpm_run_callback()
        -> pm_runtime_force_suspend()
          -> dev_pm_enable_wake_irq_check()
          -> dev_pm_enable_wake_irq_complete()

    -> suspend_enter()
      -> dpm_suspend_noirq()
        -> device_wakeup_arm_wake_irqs()
          -> dev_pm_arm_wake_irq()

To fix this issue, complete the setting of WAKE_IRQ_DEDICATED_ENABLED flag
in dev_pm_enable_wake_irq_complete() to avoid redundant irq enablement.

Fixes: 8527beb12087 ("PM: sleep: wakeirq: fix wake irq arming")
Reviewed-by: Dhruva Gole 
Signed-off-by: Qingliang Li 
Reviewed-by: Johan Hovold 
Cc: 5.16+  # 5.16+
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

x86/rfds: Mitigate Register File Data Sampling (RFDS)

2024-03-15T14:48:21+00:00

commit 8076fcde016c9c0e0660543e67bff86cb48a7c9c upstream.

RFDS is a CPU vulnerability that may allow userspace to infer kernel
stale data previously used in floating point registers, vector registers
and integer registers. RFDS only affects certain Intel Atom processors.

Intel released a microcode update that uses VERW instruction to clear
the affected CPU buffers. Unlike MDS, none of the affected cores support
SMT.

Add RFDS bug infrastructure and enable the VERW based mitigation by
default, that clears the affected buffers just before exiting to
userspace. Also add sysfs reporting and cmdline parameter
"reg_file_data_sampling" to control the mitigation.

For details see:
Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst

Signed-off-by: Pawan Gupta 
Signed-off-by: Dave Hansen 
Reviewed-by: Thomas Gleixner 
Acked-by: Josh Poimboeuf 
Signed-off-by: Greg Kroah-Hartman

pmdomain: core: Move the unused cleanup to a _sync initcall

2024-02-23T08:12:47+00:00

commit 741ba0134fa7822fcf4e4a0a537a5c4cfd706b20 upstream.

The unused clock cleanup uses the _sync initcall to give all users at
earlier initcalls time to probe. Do the same to avoid leaving some PDs
dangling at "on" (which actually happened on qcom!).

Fixes: 2fe71dcdfd10 ("PM / domains: Add late_initcall to disable unused PM domains")
Signed-off-by: Konrad Dybcio 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231227-topic-pmdomain_sync_cleanup-v1-1-5f36769d538b@linaro.org
Signed-off-by: Ulf Hansson 
Signed-off-by: Greg Kroah-Hartman

driver core: fw_devlink: Improve detection of overlapping cycles

2024-02-23T08:12:34+00:00

[ Upstream commit 6442d79d880cf7a2fff18779265d657fef0cce4c ]

fw_devlink can detect most overlapping/intersecting cycles. However it was
missing a few corner cases because of an incorrect optimization logic that
tries to avoid repeating cycle detection for devices that are already
marked as part of a cycle.

Here's an example provided by Xu Yang (edited for clarity):

                    usb
                  +-----+
   tcpc           |     |
  +-----+         |  +--|
  |     |----------->|EP|
  |--+  |         |  +--|
  |EP|<-----------|     |
  |--+  |         |  B  |
  |     |         +-----+
  |  A  |            |
  +-----+            |
     ^     +-----+   |
     |     |     |   |
     +-----|  C  |<--+
           |     |
           +-----+
           usb-phy

Node A (tcpc) will be populated as device 1-0050.
Node B (usb) will be populated as device 38100000.usb.
Node C (usb-phy) will be populated as device 381f0040.usb-phy.

The description below uses the notation:
consumer --> supplier
child ==> parent

1. Node C is populated as device C. No cycles detected because cycle
   detection is only run when a fwnode link is converted to a device link.

2. Node B is populated as device B. As we convert B --> C into a device
   link we run cycle detection and find and mark the device link/fwnode
   link cycle:
   C--> A --> B.EP ==> B --> C

3. Node A is populated as device A. As we convert C --> A into a device
   link, we see it's already part of a cycle (from step 2) and don't run
   cycle detection. Thus we miss detecting the cycle:
   A --> B.EP ==> B --> A.EP ==> A

Looking at it another way, A depends on B in one way:
A --> B.EP ==> B

But B depends on A in two ways and we only detect the first:
B --> C --> A
B --> A.EP ==> A

To detect both of these, we remove the incorrect optimization attempt in
step 3 and run cycle detection even if the fwnode link from which the
device link is being created has already been marked as part of a cycle.

Reported-by: Xu Yang 
Closes: https://lore.kernel.org/lkml/DU2PR04MB8822693748725F85DC0CB86C8C792@DU2PR04MB8822.eurprd04.prod.outlook.com/
Fixes: 3fb16866b51d ("driver core: fw_devlink: Make cycle detection more robust")
Signed-off-by: Saravana Kannan 
Tested-by: Xu Yang 
Link: https://lore.kernel.org/r/20240202095636.868578-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

driver core: Fix device_link_flag_is_sync_state_only()

2024-02-23T08:12:29+00:00

commit 7fddac12c38237252431d5b8af7b6d5771b6d125 upstream.

device_link_flag_is_sync_state_only() correctly returns true on the flags
of an existing device link that only implements sync_state() functionality.
However, it incorrectly and confusingly returns false if it's called with
DL_FLAG_SYNC_STATE_ONLY.

This bug doesn't manifest in any of the existing calls to this function,
but fix this confusing behavior to avoid future bugs.

Fixes: 67cad5c67019 ("driver core: fw_devlink: Add DL_FLAG_CYCLE support to device links")
Signed-off-by: Saravana Kannan 
Tested-by: Xu Yang 
Link: https://lore.kernel.org/r/20240202095636.868578-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman

arm64: irq: set the correct node for VMAP stack

2024-02-05T20:12:46+00:00

[ Upstream commit 75b5e0bf90bffaca4b1f19114065dc59f5cc161f ]

In current code, init_irq_stacks() will call cpu_to_node().
The cpu_to_node() depends on percpu "numa_node" which is initialized in:
     arch_call_rest_init() --> rest_init() -- kernel_init()
	--> kernel_init_freeable() --> smp_prepare_cpus()

But init_irq_stacks() is called in init_IRQ() which is before
arch_call_rest_init().

So in init_irq_stacks(), the cpu_to_node() does not work, it
always return 0. In NUMA, it makes the node 1 cpu accesses the IRQ stack which
is in the node 0.

This patch fixes it by:
  1.) export the early_cpu_to_node(), and use it in the init_irq_stacks().
  2.) change init_irq_stacks() to __init function.

Reviewed-by: Catalin Marinas 
Signed-off-by: Huang Shijie 
Link: https://lore.kernel.org/r/20231124031513.81548-1-shijie@os.amperecomputing.com
Signed-off-by: Will Deacon 
Signed-off-by: Sasha Levin

PM: sleep: Fix possible deadlocks in core system-wide PM code

2024-02-01T00:17:09+00:00

[ Upstream commit 7839d0078e0d5e6cc2fa0b0dfbee71de74f1e557 ]

It is reported that in low-memory situations the system-wide resume core
code deadlocks, because async_schedule_dev() executes its argument
function synchronously if it cannot allocate memory (and not only in
that case) and that function attempts to acquire a mutex that is already
held.  Executing the argument function synchronously from within
dpm_async_fn() may also be problematic for ordering reasons (it may
cause a consumer device's resume callback to be invoked before a
requisite supplier device's one, for example).

Address this by changing the code in question to use
async_schedule_dev_nocall() for scheduling the asynchronous
execution of device suspend and resume functions and to directly
run them synchronously if async_schedule_dev_nocall() returns false.

Link: https://lore.kernel.org/linux-pm/ZYvjiqX6EsL15moe@perf/
Reported-by: Youngmin Nam 
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Stanislaw Gruszka 
Tested-by: Youngmin Nam 
Reviewed-by: Ulf Hansson 
Cc: 5.7+  # 5.7+: 6aa09a5bccd8 async: Split async_schedule_node_domain()
Cc: 5.7+  # 5.7+: 7d4b5d7a37bd async: Introduce async_schedule_dev_nocall()
Cc: 5.7+  # 5.7+
Signed-off-by: Sasha Levin

PM: core: Remove unnecessary (void *) conversions

2024-02-01T00:17:09+00:00

[ Upstream commit 73d73f5ee7fb0c42ff87091d105bee720a9565f1 ]

Assignments from pointer variables of type (void *) do not require
explicit type casts, so remove such type cases from the code in
drivers/base/power/main.c where applicable.

Signed-off-by: Li zeming 
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki 
Stable-dep-of: 7839d0078e0d ("PM: sleep: Fix possible deadlocks in core system-wide PM code")
Signed-off-by: Sasha Levin

rtc: Extend timeout for waiting for UIP to clear to 1s

2024-02-01T00:17:01+00:00

commit cef9ecc8e938dd48a560f7dd9be1246359248d20 upstream.

Specs don't say anything about UIP being cleared within 10ms. They
only say that UIP won't occur for another 244uS. If a long NMI occurs
while UIP is still updating it might not be possible to get valid
data in 10ms.

This has been observed in the wild that around s2idle some calls can
take up to 480ms before UIP is clear.

Adjust callers from outside an interrupt context to wait for up to a
1s instead of 10ms.

Cc:   # 6.1.y
Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP")
Reported-by: Carsten Hatger 
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217626
Tested-by: Mateusz Jończyk 
Reviewed-by: Mateusz Jończyk 
Acked-by: Mateusz Jończyk 
Signed-off-by: Mario Limonciello 
Link: https://lore.kernel.org/r/20231128053653.101798-5-mario.limonciello@amd.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Greg Kroah-Hartman