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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/md/dm-vdo/completion.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
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Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'drivers/md/dm-vdo/completion.c')
-rw-r--r--drivers/md/dm-vdo/completion.c145
1 files changed, 145 insertions, 0 deletions
diff --git a/drivers/md/dm-vdo/completion.c b/drivers/md/dm-vdo/completion.c
new file mode 100644
index 000000000..2f00acbb3
--- /dev/null
+++ b/drivers/md/dm-vdo/completion.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#include "completion.h"
+
+#include <linux/kernel.h>
+
+#include "logger.h"
+#include "permassert.h"
+
+#include "status-codes.h"
+#include "types.h"
+#include "vio.h"
+#include "vdo.h"
+
+/**
+ * DOC: vdo completions.
+ *
+ * Most of vdo's data structures are lock free, each either belonging to a single "zone," or
+ * divided into a number of zones whose accesses to the structure do not overlap. During normal
+ * operation, at most one thread will be operating in any given zone. Each zone has a
+ * vdo_work_queue which holds vdo_completions that are to be run in that zone. A completion may
+ * only be enqueued on one queue or operating in a single zone at a time.
+ *
+ * At each step of a multi-threaded operation, the completion performing the operation is given a
+ * callback, error handler, and thread id for the next step. A completion is "run" when it is
+ * operating on the correct thread (as specified by its callback_thread_id). If the value of its
+ * "result" field is an error (i.e. not VDO_SUCCESS), the function in its "error_handler" will be
+ * invoked. If the error_handler is NULL, or there is no error, the function set as its "callback"
+ * will be invoked. Generally, a completion will not be run directly, but rather will be
+ * "launched." In this case, it will check whether it is operating on the correct thread. If it is,
+ * it will run immediately. Otherwise, it will be enqueue on the vdo_work_queue associated with the
+ * completion's "callback_thread_id". When it is dequeued, it will be on the correct thread, and
+ * will get run. In some cases, the completion should get queued instead of running immediately,
+ * even if it is being launched from the correct thread. This is usually in cases where there is a
+ * long chain of callbacks, all on the same thread, which could overflow the stack. In such cases,
+ * the completion's "requeue" field should be set to true. Doing so will skip the current thread
+ * check and simply enqueue the completion.
+ *
+ * A completion may be "finished," in which case its "complete" field will be set to true before it
+ * is next run. It is a bug to attempt to set the result or re-finish a finished completion.
+ * Because a completion's fields are not safe to examine from any thread other than the one on
+ * which the completion is currently operating, this field is used only to aid in detecting
+ * programming errors. It can not be used for cross-thread checking on the status of an operation.
+ * A completion must be "reset" before it can be reused after it has been finished. Resetting will
+ * also clear any error from the result field.
+ **/
+
+void vdo_initialize_completion(struct vdo_completion *completion,
+ struct vdo *vdo,
+ enum vdo_completion_type type)
+{
+ memset(completion, 0, sizeof(*completion));
+ completion->vdo = vdo;
+ completion->type = type;
+ vdo_reset_completion(completion);
+}
+
+static inline void assert_incomplete(struct vdo_completion *completion)
+{
+ VDO_ASSERT_LOG_ONLY(!completion->complete, "completion is not complete");
+}
+
+/**
+ * vdo_set_completion_result() - Set the result of a completion.
+ * @completion: The completion to update.
+ * @result: The result to set.
+ *
+ * Older errors will not be masked.
+ */
+void vdo_set_completion_result(struct vdo_completion *completion, int result)
+{
+ assert_incomplete(completion);
+ if (completion->result == VDO_SUCCESS)
+ completion->result = result;
+}
+
+/**
+ * vdo_launch_completion_with_priority() - Run or enqueue a completion.
+ * @completion: The completion to launch.
+ * @priority: The priority at which to enqueue the completion.
+ *
+ * If called on the correct thread (i.e. the one specified in the completion's callback_thread_id
+ * field) and not marked for requeue, the completion will be run immediately. Otherwise, the
+ * completion will be enqueued on the specified thread.
+ */
+void vdo_launch_completion_with_priority(struct vdo_completion *completion,
+ enum vdo_completion_priority priority)
+{
+ thread_id_t callback_thread = completion->callback_thread_id;
+
+ if (completion->requeue || (callback_thread != vdo_get_callback_thread_id())) {
+ vdo_enqueue_completion(completion, priority);
+ return;
+ }
+
+ vdo_run_completion(completion);
+}
+
+/** vdo_finish_completion() - Mark a completion as complete and then launch it. */
+void vdo_finish_completion(struct vdo_completion *completion)
+{
+ assert_incomplete(completion);
+ completion->complete = true;
+ if (completion->callback != NULL)
+ vdo_launch_completion(completion);
+}
+
+void vdo_enqueue_completion(struct vdo_completion *completion,
+ enum vdo_completion_priority priority)
+{
+ struct vdo *vdo = completion->vdo;
+ thread_id_t thread_id = completion->callback_thread_id;
+
+ if (VDO_ASSERT(thread_id < vdo->thread_config.thread_count,
+ "thread_id %u (completion type %d) is less than thread count %u",
+ thread_id, completion->type,
+ vdo->thread_config.thread_count) != VDO_SUCCESS)
+ BUG();
+
+ completion->requeue = false;
+ completion->priority = priority;
+ completion->my_queue = NULL;
+ vdo_enqueue_work_queue(vdo->threads[thread_id].queue, completion);
+}
+
+/**
+ * vdo_requeue_completion_if_needed() - Requeue a completion if not called on the specified thread.
+ * @completion: The completion to requeue.
+ * @callback_thread_id: The thread on which to requeue the completion.
+ *
+ * Return: True if the completion was requeued; callers may not access the completion in this case.
+ */
+bool vdo_requeue_completion_if_needed(struct vdo_completion *completion,
+ thread_id_t callback_thread_id)
+{
+ if (vdo_get_callback_thread_id() == callback_thread_id)
+ return false;
+
+ completion->callback_thread_id = callback_thread_id;
+ vdo_enqueue_completion(completion, VDO_WORK_Q_DEFAULT_PRIORITY);
+ return true;
+}