The currently running task cur may not be a CFS task, such as
an RT or Deadline task. For non-CFS tasks, the task_util(cur)
utilization average is not maintained, so this might pass a
stale or meaningless value to can_migrate_llc().
Check if the task is CFS before getting its task_util().
This bug was reported by sashiko.
Fixes: 714059f79f ("sched/cache: Handle moving single tasks to/from their preferred LLC")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/f9161133cf040d286dca11344a112c5ef2a5253d.1778703694.git.tim.c.chen@linux.intel.com
There is a race condition that, after a task is enqueued
on a runqueue, task_llc(p) may change due to CPU hotplug,
because the llc_id is dynamically allocated and adjusted
at runtime.
Therefore, checking task_llc(p) to determine whether the
task is being dequeued from its preferred LLC is unreliable
and can cause inconsistent values.
To fix this problem, record whether p is enqueued on its
preferred LLC, in order to pair with account_llc_dequeue()
to maintain a consistent nr_pref_llc_running per runqueue.
This bug was reported by sashiko, and the solution was once
suggested by Prateek.
Fixes: 46afe3af7e ("sched/cache: Track LLC-preferred tasks per runqueue")
Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/0c8c6a1571d66792a4d2ff0103ba3cc13e059046.1778703694.git.tim.c.chen@linux.intel.com
mm->sc_stat.cpu is written by task_cache_work() and could be read
locklessly by several functions on other CPUs. Use READ_ONCE and
WRITE_ONCE on mm->sc_stat.cpu access and write to prevent inconsistent
values from compiler optimizations when there are multiple accesses.
For example in get_pref_llc(), if the writer updated the field between
two compiler-generated loads, the validation (e.g., cpu != -1) and
subsequent use (e.g., llc_id(cpu)) could operate on different values,
allowing a negative CPU ID to be used as an index.
Leave plain write in mm_init_sched(), where the mm is not
yet visible to other CPUs.
This bug was reported by sashiko.
Fixes: 47d8696b95 ("sched/cache: Assign preferred LLC ID to processes")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/63ea494f12efcf265d7134400a06cd75d7f2c310.1778703694.git.tim.c.chen@linux.intel.com
A concurrent task exit might cause a NULL pointer dereference
in account_mm_sched(). Use the locally cached mm pointer instead,
since the active_mm reference guarantees the structure remains
allocated. Meanwhile, skip the kernel thread because it has
nothing to do with cache aware scheduling.
This bug was reported by sashiko and Vern.
Fixes: df0d984759 ("sched/cache: Introduce infrastructure for cache-aware load balancing")
Reported-by: Vern Hao <haoxing990@gmail.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/09cf7ee3-6e27-4505-9692-4b4a4707c8b2@gmail.com/
Link: https://patch.msgid.link/066d8cfa45d4822bf4367e788c50377c66bbcc82.1778703694.git.tim.c.chen@linux.intel.com
rcu_dereference_all() should be used to access the
sd_llc domain under RCU protection.
This bug was reported by sashiko.
Fixes: df0d984759 ("sched/cache: Introduce infrastructure for cache-aware load balancing")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/2dc49455e861215d8059a1c877953f0b95990038.1778703694.git.tim.c.chen@linux.intel.com
Introduce a set of debugfs knobs to control how aggressively the
cache aware scheduling does the task aggregation.
(1) aggr_tolerance
With sched_cache enabled, the scheduler uses a process's footprint
as a proxy for its LLC footprint to determine if aggregating tasks
on the preferred LLC could cause cache contention. If the footprint
exceeds the LLC size, aggregation is skipped. Since the kernel
cannot efficiently track per-task cache usage (resctrl is
user-space only), userspace can provide a more accurate hint.
Introduce /sys/kernel/debug/sched/llc_balancing/aggr_tolerance to
let users control how strictly footprint limits aggregation. Values
range from 0 to 100:
- 0: Cache-aware scheduling is disabled.
- 1: Strict; tasks with footprint larger than LLC size are skipped.
- >=100: Aggressive; tasks are aggregated regardless of footprint.
For example, with a 32MB L3 cache:
- aggr_tolerance=1 -> tasks with footprint > 32MB are skipped.
- aggr_tolerance=99 -> tasks with footprint > 784GB are skipped
(784GB = (1 + (99 - 1) * 256) * 32MB).
Similarly, /sys/kernel/debug/sched/llc_balancing/aggr_tolerance also
controls how strictly the number of active threads is considered when
doing cache aware load balance. The number of SMTs is also considered.
High SMT counts reduce the aggregation capacity, preventing excessive
task aggregation on SMT-heavy systems like Power10/Power11.
Yangyu suggested introducing separate aggregation controls for the
number of active threads and memory footprint checks. Since there are
plans to add per-process/task group controls, fine-grained tunables are
deferred to that implementation.
(2) epoch_period, epoch_affinity_timeout,
imb_pct, overaggr_pct are also turned into tunables.
Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Suggested-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com>
Suggested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Suggested-by: Tingyin Duan <tingyin.duan@gmail.com>
Suggested-by: Jianyong Wu <jianyong.wu@outlook.com>
Suggested-by: Yangyu Chen <cyy@cyyself.name>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Tingyin Duan <tingyin.duan@gmail.com>
Link: https://patch.msgid.link/1c62cc060ba2b33d7b1f0ed98b3390128edbae93.1778703694.git.tim.c.chen@linux.intel.com
Prateek and Tingyin reported that memory-intensive workloads (such as
stream) can saturate memory bandwidth and caches on the preferred LLC
when sched_cache aggregates too many threads.
To mitigate this, estimate a process's memory footprint by comparing
its NUMA balancing fault statistics to the size of the LLC. If the
footprint exceeds the LLC size, skip cache-aware scheduling.
Note that footprint is only an approximation of the memory footprint,
since the kernel lacks suitable metrics to estimate the real working
set. If a user-provided hint is available in the future, it would be
more accurate. A later patch will allow users to provide a hint to
adjust this threshold.
Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Suggested-by: Vern Hao <vernhao@tencent.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Tingyin Duan <tingyin.duan@gmail.com>
Link: https://patch.msgid.link/95cf64a385bcc12f18dcebe9d59e8d3ba8bb318f.1778703694.git.tim.c.chen@linux.intel.com
Cache aware scheduling needs to know the LLC size that a process
can use, so as to avoid memory-intensive tasks from being
over-aggregated on a single LLC.
Introduce a preparation patch to add get_effective_llc_bytes() to
get the LLC size that a CPU can use. The function can be further
enhanced by subtracting the LLC cache ways reserved by resctrl
(CAT in Intel RDT, etc).
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Tingyin Duan <tingyin.duan@gmail.com>
Link: https://patch.msgid.link/37afee09ff608034da0ce149e72d33b6f4698edf.1778703694.git.tim.c.chen@linux.intel.com
For a single thread, the current wakeup path tends to place it
on the same LLC where it was previously running with cache-hot
data. There is no need to enable cache-aware scheduling for
single-threaded processes for the following reasons:
1. Cache-aware scheduling primarily benefits multi-threaded
processes where threads share data. Single-threaded processes
typically have no inter-thread data sharing and thus gain little.
2. Enabling it incurs the additional overhead of tracking the
thread's residency in the LLCs.
3. Bypassing single-threaded processes avoids excessive
concentration of such tasks on a single LLC.
Nevertheless, this check can be omitted if users explicitly
provide hints for such single-threaded workloads where different
processes have shared memory, e.g., via prctl() or other interfaces
to be added in the future.
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Tingyin Duan <tingyin.duan@gmail.com>
Link: https://patch.msgid.link/8a59a13aa58fdb48e410ecb2aabd97fe3ea5d256.1778703694.git.tim.c.chen@linux.intel.com
A performance regression was observed by Prateek when running hackbench
with many threads per process (high fd count). To avoid this, processes
with a large number of active threads are excluded from cache-aware
scheduling.
With sched_cache enabled, record the number of active threads in each
process during the periodic task_cache_work(). While iterating over
CPUs, if the currently running task belongs to the same process as the
task that launched task_cache_work(), increment the active thread count.
If the number of active threads within the process exceeds the number
of Cores (divided by the SMT number) in the LLC, do not enable
cache-aware scheduling. However, on systems with a smaller number of
CPUs within 1 LLC, like Power10/Power11 with SMT4 and an LLC size of 4,
this check effectively disables cache-aware scheduling for any process.
One possible solution suggested by Peter is to use an LLC-mask instead
of a single LLC value for preference. Once there are a 'few' LLCs as
preference, this constraint becomes a little easier. It could be an
enhancement in the future.
For users who wish to perform task aggregation regardless, a debugfs knob
is provided for tuning in a subsequent change.
Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Suggested-by: Aaron Lu <ziqianlu@bytedance.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Tingyin Duan <tingyin.duan@gmail.com>
Link: https://patch.msgid.link/d076cd21a8e6c6341d1e2d927e118db770ebb650.1778703694.git.tim.c.chen@linux.intel.com
Scanning online CPUs to calculate the occupancy might be
time-consuming. Only allow 1 thread of the process to scan
the CPUs at the same time, which is similar to what
NUMA balance does in task_numa_work().
Signed-off-by: Jianyong Wu <wujianyong@hygon.cn>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/5672b52e588b855b01e5a1a17822f7c6c7237a3d.1778703694.git.tim.c.chen@linux.intel.com
css_rstat_updated() is exposed as a BPF kfunc and accepts a
caller-provided cpu argument. The function uses cpu for per-cpu rstat
lookups without checking whether it refers to a valid possible CPU.
A BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an
invalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu ==
0x7fffffff triggers:
UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9
index 2147483647 is out of range for type 'long unsigned int [64]'
Call Trace:
css_rstat_updated
bpf_iter_run_prog
cgroup_iter_seq_show
bpf_seq_read
Add cpu validation to the BPF-facing css_rstat_updated() kfunc and
move the common implementation to __css_rstat_updated() for in-kernel
callers.
Fixes: a319185be9 ("cgroup: bpf: enable bpf programs to integrate with rstat")
Signed-off-by: Qing Ming <a0yami@mailbox.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
While an srcu_struct structure is in the midst of switching from CPU-0
to all-CPUs state, it can attempt to invoke callbacks for CPUs that
have never been online. Worse yet, it can attempt in invoke callbacks
for CPUs that never will be online, even including imaginary CPUs not in
cpu_possible_mask. This can cause hangs on s390, which is not set up to
deal with workqueue handlers being scheduled on such CPUs. This commit
therefore causes Tree SRCU to refrain from queueing workqueue handlers
on CPUs that have not yet (and might never) come online.
Because callbacks are not invoked on CPUs that have not been
online, it is an error to invoke call_srcu(), synchronize_srcu(), or
synchronize_srcu_expedited() on a CPU that is not yet fully online.
However, it turns out to be less code to redirect the callbacks
from too-early invocations of call_srcu() than to warn about such
invocations. This commit therefore also redirects callbacks queued on
not-yet-fully-online CPUs to the boot CPU.
Reported-by: Vasily Gorbik <gor@linux.ibm.com>
Fixes: 61bbcfb505 ("srcu: Push srcu_node allocation to GP when non-preemptible")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Samir <samir@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Boqun Feng <boqun@kernel.org>
All accesses to the event counters are serialized by rdmacg_mutex,
making the READ_ONCE() annotations unnecessary. Remove them.
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
During development, it is useful to see which mailboxes are currently
obtained. Use a seq-file in debugfs to list the currently registered
controllers and their used channels. Example output from a Renesas R-Car
X5H based system:
# cat /sys/kernel/debug/mailbox/mailbox_summary
189e0000.system-controller:
0: c1000000.mailbox_test_send_to_recv
1: c1000100.mailbox_test_recv_to_send
128: c1000100.mailbox_test_recv_to_send
129: c1000000.mailbox_test_send_to_recv
189e1000.system-controller:
4: scmi_dev.1
5: scmi_dev.2
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
If the optional startup() callbacks fails, we need to clear some states.
Currently, this is done by freeing the channel. This does, however, more
than needed which creates problems. Namely, it is calling the shutdown()
callback. This is totally not intuitive. No user expects that shutdown()
is called when startup() fails, similar to remove() not being called
when probe() fails. Currently, quite some mailbox users register the IRQ
in startup() and free them in shutdown(). These drivers will get a WARN
about freeing an already free IRQ. Other subtle issues could arise from
this unexpected behaviour.
To solve this problem, introduce a helper which does the minimal cleanup
and use it in both, in free_channel() and after startup() failed.
Link: https://sashiko.dev/#/patchset/20260402112709.13002-1-wsa%2Brenesas%40sang-engineering.com # second issue
Fixes: 2b6d83e2b8 ("mailbox: Introduce framework for mailbox")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
When the mailbox controller failed transmitting message, the error code
was only passed to the client's tx done handler and not to
mbox_send_message() in blocking mode. For this reason, the function could
return a false success. This commit resolves the issue by introducing the
tx status and checking it before mbox_send_message() returns.
This commit works with the premise that the multi-threads' access to a
channel in blocking mode is serialized by clients, not by the mailbox
APIs, since the current mbox_send_message() in blocking mode does not
support multi-threads.
Signed-off-by: Joonwon Kang <joonwonkang@google.com>
Reviewed-by: Sudeep Holla <sudeep.holla@kernel.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Unlike in non-blocking mode, multi-thread has not been supported in
blocking mode. This commit is to prevent clients from having wrong
assumption by explicitly specifying this fact to the API doc.
Signed-off-by: Joonwon Kang <joonwonkang@google.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
When the SOF audio driver fails to initialize (e.g. firmware boot
timeout), its devres unwind frees the snd_sof_dev object that the
mailbox client (mtk-adsp-ipc) reaches via chan->cl->rx_callback.
The mtk-adsp-mailbox shutdown clears the mailbox command registers
but leaves the IRQ line unmasked, so a late interrupt can still
queue a threaded handler after mbox_free_channel() had cleared
chan->cl, and mbox_chan_received_data() would then trigger UAF:
BUG: KASAN: slab-use-after-free in sof_ipc3_validate_fw_version
sof_ipc3_validate_fw_version
sof_ipc3_do_rx_work
sof_ipc3_rx_msg
mt8196_dsp_handle_request
mtk_adsp_ipc_recv
mbox_chan_received_data
mtk_adsp_mbox_isr
irq_thread_fn
Freed by task ...:
kfree
devres_release_all
really_probe
... (sof-audio-of-mt8196 probe failure)
The crash was observed roughly three seconds after the failed probe.
disable_irq() in shutdown and enable_irq() in startup. disable_irq()
also waits for any in-flight interrupts, so by the time
mbox_free_channel() proceeds to clear chan->cl no rx_callback can run.
In addition, request the IRQ with IRQF_NO_AUTOEN so it stays masked
between probe and the first client bind — otherwise an early interrupt
can crash on chan->cl == NULL in mbox_chan_received_data().
Fixes: af2dfa96c5 ("mailbox: mediatek: add support for adsp mailbox controller")
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Various names for Qualcomm as a company are used in user-visible config
options: QCOM, Qualcomm and Qualcomm Technologies. Switch to unified
"Qualcomm" so it will be easier for users to identify the options when
for example running menuconfig.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Leaving these dead definitions in place hides which registers are
actually being used by the hardware, making the driver harder to read
and maintain. Remove them to clean up the file.
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Alexey Klimov <alexey.klimov@linaro.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Document the Inter-Processor Communication Controller on the Qualcomm
Hawi Platform, which will be used to route interrupts across various
subsystems found on the SoC.
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Document CPU Control Processor (CPUCP) mailbox controller for Qualcomm
Hawi SoCs. It is software compatible with X1E80100 CPUCP mailbox
controller hence fallback to it.
Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
The Nord SoC CPUCP mailbox supports 16 IPC channels, compared to 3 on
x1e80100. The existing driver hardcodes the channel count via a
compile-time constant (APSS_CPUCP_IPC_CHAN_SUPPORTED), making it
impossible to support hardware with a different number of channels.
Introduce a qcom_cpucp_mbox_data per-hardware configuration struct that
carries the channel count, and retrieve it via of_device_get_match_data()
at probe time. Switch the channel array from a fixed-size member to a
dynamically allocated buffer sized from the hardware data. Update the
x1e80100 entry to supply its own data struct, and add a new Nord entry
with num_chans = 16.
Signed-off-by: Deepti Jaggi <deepti.jaggi@oss.qualcomm.com>
Signed-off-by: Shawn Guo <shengchao.guo@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Document CPUSS Control Processor (CPUCP) mailbox controller for Qualcomm
Nord SoC, which is compatible with X1E80100 CPUCP, even though it supports
more IPC channels.
Signed-off-by: Deepti Jaggi <deepti.jaggi@oss.qualcomm.com>
Signed-off-by: Shawn Guo <shengchao.guo@oss.qualcomm.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
mpfs_mbox_inbox_isr() writes to the sysreg scb syscon, not the control
scb syscon, but checks for the presence of the latter. Ultimately this
makes little difference because if one syscon is present, both will be.
Fixes: a4123ffab9 ("mailbox: mpfs: support new, syscon based, devicetree configuration")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Three sideband reply parsers read 16-bit fields as:
val = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
and check bounds only after the fact. When idx == raw->curlen,
raw->msg[idx+1] reads one byte past the received message data into
the following struct fields (curchunk_len, curchunk_idx, curlen).
Affected functions:
- drm_dp_sideband_parse_enum_path_resources_ack()
full_payload_bw_number and avail_payload_bw_number fields
- drm_dp_sideband_parse_allocate_payload_ack()
allocated_pbn field
- drm_dp_sideband_parse_query_payload_ack()
allocated_pbn field
Fix by using a single combined check (idx + 2 > curlen) before each
2-byte read. Since the check is strictly tighter than idx > curlen,
no separate step is needed.
Fixes: ad7f8a1f9c ("drm/helper: add Displayport multi-stream helper (v0.6)")
Cc: <stable@vger.kernel.org> # v3.17+
Signed-off-by: Ashutosh Desai <ashutoshdesai993@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
[added fixes tag]
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patch.msgid.link/20260510203128.2884846-1-ashutoshdesai993@gmail.com
drm_dp_sideband_parse_remote_dpcd_read() reads num_bytes from the raw
message and then unconditionally does:
memcpy(bytes, &raw->msg[idx], num_bytes);
without checking that idx + num_bytes <= raw->curlen. raw->msg[] is
256 bytes; if a malicious or misbehaving MST hub sets num_bytes larger
than the remaining payload, the memcpy reads past the received data
into whatever follows in raw->msg[].
drm_dp_sideband_parse_remote_i2c_read_ack() has the same flaw (noted
with a /* TODO check */ comment since the code was introduced).
Fix both functions by using a single combined check
(idx + num_bytes > curlen) before each memcpy. Since num_bytes is u8,
it is always >= 0, so this strictly subsumes the simpler idx > curlen
form and no separate step is needed.
Fixes: ad7f8a1f9c ("drm/helper: add Displayport multi-stream helper (v0.6)")
Cc: <stable@vger.kernel.org> # v3.17+
Signed-off-by: Ashutosh Desai <ashutoshdesai993@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
[added missing fixes tag]
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patch.msgid.link/20260510201733.2882224-1-ashutoshdesai993@gmail.com
When power control for downstream devices was introduced in the
mediatek-gen3 PCIe controller driver, only the power to the downstream
devices was cut when the controller driver is removed. This matched
existing behavior, but in hindsight a proper power down sequence should
have been followed.
Call mtk_pcie_devices_power_down() on driver removal so that in addition
to removing power from the downstream devices, PERST# is asserted.
Fixes: 1a152e2194 ("PCI: mediatek-gen3: Integrate new pwrctrl API")
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260505105918.1823170-1-wenst@chromium.org
Add a .shutdown() callback to control the timing of PERST# and power during
system shutdown to ensure that PERST# is asserted before power to the
connector is removed, as required by PCIe CEM r6.0, sec 2.2.
Signed-off-by: Jian Yang <jian.yang@mediatek.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260413071401.1151-3-jian.yang@mediatek.com
Some MediaTek chips stop generating REFCLK if the PCIE_PHY_RSTB signal of
PCIe controller is asserted at the start of mtk_pcie_devices_power_up().
But the driver deasserts PCIE_PHY_RSTB together with PCIE_PE_RSTB signal
that is used to deassert PERST#. This violates PCIe CEM r6.0, sec 2.11.2,
which mandates waiting for 100ms (PCIE_T_PVPERL_MS) after power becomes
stable.
Move the MAC, PHY and BRG reset deassert code above the PCIE_T_PVPERL_MS
delay and leave the PCIE_PE_RSTB deassertion after the delay.
Add the 10ms delay mentioned in the MediaTek datasheet after asserting
PCIE_BRG_RSTB and before accessing the PCIE_RST_CTRL_REG register.
Signed-off-by: Jian Yang <jian.yang@mediatek.com>
[mani: commit log and comments rewording]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260413071401.1151-2-jian.yang@mediatek.com
Herve Codina <herve.codina@bootlin.com> says:
On some embedded system boards, audio amplifiers are designed using
discrete components such as op-amp, several resistors and switches to
either adjust the gain (switching resistors) or fully switch the
audio signal path (mute and/or bypass features).
Those switches are usually driven by simple GPIOs.
This kind of amplifiers are not handled in ASoC and the fallback is to
let the user-space handle those GPIOs out of the ALSA world.
In order to have those kind of amplifiers fully integrated in the audio
stack, this series introduces the audio-gpio-amp to handle them.
This new ASoC component allows to have the amplifiers seen as ASoC
auxiliarty devices and so it allows to control them through audio mixer
controls.
In order to ease the review, I choose to split modifications related
to the merge of the gpio-audio-amp part into the simple-amplfier driver
in several commits.
Link: https://patch.msgid.link/20260513081702.317117-1-herve.codina@bootlin.com
After reworking the simple-amplifier driver and adding support for
gpio-audio-amp in the driver, add myself as the author of the
gpio-audio-amp part of the driver and add a related copyright.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-17-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The possible gain values can be described using labels instead of gain
values in dB.
Those different labels are attached to a gpio values using the
gain-labels property.
Using the gain-labels description is mutually exclusive with gain-ranges
description used to describe the relationship between gpios values and
gain values.
Handle the gain-labels description and the related kcontrol.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-16-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The mapping between physical gain values and gpio values can be
expressed using ranges described in the gain-ranges property.
This gain-ranges property is an array of ranges.
Each range in the array is defined by the first point and last point in
the range. Those points are a pair of values, the gpios value and the
related gain (dB) value.
With that, a given range defines N possible items (from the first point
gpios value to the last point gpios value) in order to set a gain from
the first point gain value to the last point gain value.
Handle this description and the related kcontrol.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-15-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Several gpios can be used to control the amplifier gain.
Add basic support for those gpios.
This basic support doesn't include any mapping between the GPIOs value
and the physical gain value (dB).
The support for this kind of mapping will be added later on.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-14-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
A gpio can be used to control the amplifier bypass feature.
Add support for this bypass gpio in the same way as it has been done for
the mute gpio.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-13-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The gpio-audio-amp devices can use additional power supplies:
- vddio,
- vdda1,
- vdda2
Add support for those additional power supplies.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-11-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Improve the simple-amplifier introducing preliminary support for
gpio-audio-amp.
Those amplifiers are amplifiers driven by gpios.
This support introduction doesn't handle any GPIO yet but introduces
the compatible strings and the related DAPM table.
Two gpio-audio-amp are available: A mono and a stereo version.
The mono version has only one audio channel and gpio settings impact
features such as the gain or mute of this sole channel.
The stereo version has two channels (left and right). Gpio settings
impact both channels in the same manner and at the same time. For
instance, the gain setting set the gain of both channels as well as
the mute setting mutes both channels.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-10-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The simple-amplifier set the DAPM wigets and routes table in the ASoC
component driver. This is perfectly fine when the component has well
known DAPM tables.
The simple-amplifier is going to handle several kind of components based
on the driver compatible string. The DAPM table will not be the same for
all components supported by the driver.
In order to have different DAPM table based on matching compatible
strings, move those tables from the ASoC component driver to the device
compatible string matching data.
Add those DAPM widgets and routes dynamically during the ASoC component
probe operation.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-9-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The simple-amplifier driver use 'priv' as variable name for its private
data (struct simple_amp).
With the support for gpio-audio-amp, more functions and data
structures will be added.
Those future additions will add more complexity in data manipulation and
will make the 'priv' term error prone.
In order to clearly identify the struct simple_amp private data, use
'simple_amp' as variable name when this structure is involved.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-8-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The drv_event() is used to handle power events related to the DRV item.
Later, with the support for gpio-audio-amp, this function will be
also used to handle power events related to the PGA item.
Also, more functions will be added in the driver and it is a common
usage to prefix functions based on the driver name.
Rename the drv_event() function to simple_amp_power_event() to follow
common usage and get rid of the 'drv' term.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-7-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The simple-amplifier Use CONFIG_OF flag for its of_device_id table
and of_match_ptr() when it assigns the table in the driver declaration.
This is no more needed. Drop them.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-6-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The simple-amplifier driver is a platform device driver.
Add missing include files related to this kind of driver.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-5-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
DRV_NAME is defined and used only in the simple-amplifier driver
declaration.
Remove the useless defined and use directly the value in the driver
declaration itself.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Link: https://patch.msgid.link/20260513081702.317117-4-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
