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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-24 08:46:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-24 08:46:03 -0700
commitcf9610f9116d55c5a66ef9f1faecacabd93a9322 (patch)
tree757a3d280760c654767631cab5ad8af2d86d1848 /include/drm/spsc_queue.h
downloadlinux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.tar.gz
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Merge tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlgrafted
Pull pin control updates from Linus Walleij: "Core changes: - Use the non-blocking mux_state_try_select() in the generic MUX pin control back-end - Free pin maps on pinctrl_generic_to_map() failure in the core helpers New hardware pin control: - Qualcomm Maili TLMM SoC, PMG1110 PMIC, and Eliza LPASS LPI TLMM SoC (this is for the low power audio, LPASS = Low Power Audio SubSystem portions) - Upboard support on top of the Intel pin controller - Apple T6030 and T6031 support (just compatible strings) - Samsung Exynos 8855 SoC - Mediatek MT6858 SoC - Rockchip RK3308B and RV1106 SoCs - Airoha EN7523 and AN7563 SoCs Improvements: - Qualcomm TLMM GPIOs are unconditionally marked as wakeup capable - Qualcomm improvements on top of the Qualcomm PDC (power domain controller) irqchip improvements from tglx:s tree - Qualcomm IPQ806x and IPQ9650 non-urgent pin grop fixups - The NPCM8xx driver has been put into shape fixing many pin and group definitions - Some non-urgent Tegra 264 pin assignments are fixed up - Some non-urgent fixups to Airoha AN7581 and AN7583 registers and pin assignments, missing features etc" * tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (130 commits) dt-bindings: pinctrl: Convert TI DA850 pupd to DT schema pinctrl: meson: sync some modify from A4 pinctrl: meson: a4: Add input enable pin configuration pinctrl: realtek: rtd1625: remove unused group name spdif_sel pinctrl: realtek: rtd1625: fix base_bit for VE4 GPIO 13 dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema Revert "Merge branch 'ib-rsk7204' into devel" pinctrl: rockchip: Add RV1106 pinctrl support dt-bindings: pinctrl: rockchip: Add RV1106 compatible pinctrl: rockchip: Decode drive strength in the get function pinctrl: fix PINCTRL_GENERIC_MUX not always being selectable pinctrl: airoha: add support of an7563 SoC dt-bindings: pinctrl: airoha: add support of an7563 pin controller pinctrl: airoha: try to find chip scu node by phandle first pinctrl: airoha: add support of en7523 SoC dt-bindings: pinctrl: airoha: add support of en7523 pin controller pinctrl: airoha: an7583: add support for olt pinmux pinctrl: airoha: an7583: add support for pon_alt pinmux pinctrl: airoha: an7583: add support for npu_uart pinmux dt-bindings: pinctrl: airoha: an7583: add missed features ...
Diffstat (limited to 'include/drm/spsc_queue.h')
-rw-r--r--include/drm/spsc_queue.h124
1 files changed, 124 insertions, 0 deletions
diff --git a/include/drm/spsc_queue.h b/include/drm/spsc_queue.h
new file mode 100644
index 000000000..ee9df8cc6
--- /dev/null
+++ b/include/drm/spsc_queue.h
@@ -0,0 +1,124 @@
+/*
+ * Copyright 2017 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#ifndef DRM_SCHEDULER_SPSC_QUEUE_H_
+#define DRM_SCHEDULER_SPSC_QUEUE_H_
+
+#include <linux/atomic.h>
+#include <linux/preempt.h>
+
+/** SPSC lockless queue */
+
+struct spsc_node {
+
+ /* Stores spsc_node* */
+ struct spsc_node *next;
+};
+
+struct spsc_queue {
+
+ struct spsc_node *head;
+
+ /* atomic pointer to struct spsc_node* */
+ atomic_long_t tail;
+
+ atomic_t job_count;
+};
+
+static inline void spsc_queue_init(struct spsc_queue *queue)
+{
+ queue->head = NULL;
+ atomic_long_set(&queue->tail, (long)&queue->head);
+ atomic_set(&queue->job_count, 0);
+}
+
+static inline struct spsc_node *spsc_queue_peek(struct spsc_queue *queue)
+{
+ return queue->head;
+}
+
+static inline int spsc_queue_count(struct spsc_queue *queue)
+{
+ return atomic_read(&queue->job_count);
+}
+
+static inline bool spsc_queue_push(struct spsc_queue *queue, struct spsc_node *node)
+{
+ struct spsc_node **tail;
+
+ node->next = NULL;
+
+ preempt_disable();
+
+ atomic_inc(&queue->job_count);
+ smp_mb__after_atomic();
+
+ tail = (struct spsc_node **)atomic_long_xchg(&queue->tail, (long)&node->next);
+ WRITE_ONCE(*tail, node);
+
+ /*
+ * In case of first element verify new node will be visible to the consumer
+ * thread when we ping the kernel thread that there is new work to do.
+ */
+ smp_wmb();
+
+ preempt_enable();
+
+ return tail == &queue->head;
+}
+
+
+static inline struct spsc_node *spsc_queue_pop(struct spsc_queue *queue)
+{
+ struct spsc_node *next, *node;
+
+ /* Verify reading from memory and not the cache */
+ smp_rmb();
+
+ node = READ_ONCE(queue->head);
+
+ if (!node)
+ return NULL;
+
+ next = READ_ONCE(node->next);
+ WRITE_ONCE(queue->head, next);
+
+ if (unlikely(!next)) {
+ /* slowpath for the last element in the queue */
+
+ if (atomic_long_cmpxchg(&queue->tail,
+ (long)&node->next, (long) &queue->head) != (long)&node->next) {
+ /* Updating tail failed wait for new next to appear */
+ do {
+ smp_rmb();
+ } while (unlikely(!(queue->head = READ_ONCE(node->next))));
+ }
+ }
+
+ atomic_dec(&queue->job_count);
+ return node;
+}
+
+
+
+#endif /* DRM_SCHEDULER_SPSC_QUEUE_H_ */