[PATCH v3 04/15] media: qcom: camss: Add camss-isp-bufq helper

[Loic Poulain <loic.poulain@oss.qualcomm.com>]

Add a per-queue ready-buffer FIFO helper for CAMSS offline ISP drivers.
camss_isp_bufq provides N spinlock-protected FIFO lists of ready vb2
buffers, one per queue index. This can help multi-queues management
and synchronization in ISP context.

Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 drivers/media/platform/qcom/camss/Kconfig          |  14 +++
 drivers/media/platform/qcom/camss/Makefile         |   5 +
 drivers/media/platform/qcom/camss/camss-isp-bufq.c | 101 +++++++++++++++++
 drivers/media/platform/qcom/camss/camss-isp-bufq.h | 122 +++++++++++++++++++++
 4 files changed, 242 insertions(+)

diff --git a/drivers/media/platform/qcom/camss/Kconfig b/drivers/media/platform/qcom/camss/Kconfig
index 4eda48cb1adf049a7fb6cb59b9da3c0870fe57f4..d77482f3f5eadc65856806b9b237d65ea484f267 100644
--- a/drivers/media/platform/qcom/camss/Kconfig
+++ b/drivers/media/platform/qcom/camss/Kconfig
@@ -7,3 +7,17 @@ config VIDEO_QCOM_CAMSS
 	select VIDEO_V4L2_SUBDEV_API
 	select VIDEOBUF2_DMA_SG
 	select V4L2_FWNODE
+
+config VIDEO_QCOM_CAMSS_ISP
+	tristate "Qualcomm CAMSS ISP common helpers"
+	depends on VIDEO_DEV
+	depends on MEDIA_CONTROLLER
+	select V4L2_ISP
+	select VIDEOBUF2_CORE
+	help
+	  Common helper library for Qualcomm CAMSS offline ISP drivers.
+	  Provides buffer queue management, job scheduling, MC pipeline
+	  topology builder, and ISP parameter buffer parsing.
+
+	  This module is selected automatically by drivers that need it.
+
diff --git a/drivers/media/platform/qcom/camss/Makefile b/drivers/media/platform/qcom/camss/Makefile
index 5e349b4915130c71dbff90e73102e46dfede1520..bfc05db0eada1d801839ceb8a3b157baae613053 100644
--- a/drivers/media/platform/qcom/camss/Makefile
+++ b/drivers/media/platform/qcom/camss/Makefile
@@ -29,3 +29,8 @@ qcom-camss-objs += \
 		camss-format.o \
 
 obj-$(CONFIG_VIDEO_QCOM_CAMSS) += qcom-camss.o
+
+qcom-camss-isp-objs := camss-isp-bufq.o
+
+obj-$(CONFIG_VIDEO_QCOM_CAMSS_ISP) += qcom-camss-isp.o
+
diff --git a/drivers/media/platform/qcom/camss/camss-isp-bufq.c b/drivers/media/platform/qcom/camss/camss-isp-bufq.c
new file mode 100644
index 0000000000000000000000000000000000000000..b1dcf60afcc63d112eee7bd143f08a7b4aac9a18
--- /dev/null
+++ b/drivers/media/platform/qcom/camss/camss-isp-bufq.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * camss-isp-bufq.c
+ *
+ * CAMSS ISP per-queue ready-buffer FIFO.
+ *
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "camss-isp-bufq.h"
+
+struct camss_isp_bufq *camss_isp_bufq_init(unsigned int num_queues)
+{
+	struct camss_isp_bufq *bufq;
+	unsigned int i;
+
+	bufq = kzalloc(struct_size(bufq, entries, num_queues), GFP_KERNEL);
+	if (!bufq)
+		return ERR_PTR(-ENOMEM);
+
+	bufq->num_queues = num_queues;
+
+	for (i = 0; i < num_queues; i++) {
+		INIT_LIST_HEAD(&bufq->entries[i].rdy_queue);
+		spin_lock_init(&bufq->entries[i].rdy_spinlock);
+	}
+
+	return bufq;
+}
+EXPORT_SYMBOL_GPL(camss_isp_bufq_init);
+
+void camss_isp_bufq_release(struct camss_isp_bufq *bufq)
+{
+	kfree(bufq);
+}
+EXPORT_SYMBOL_GPL(camss_isp_bufq_release);
+
+void camss_isp_bufq_queue(struct camss_isp_bufq *bufq, unsigned int queue_idx,
+			  struct vb2_v4l2_buffer *vbuf)
+{
+	struct camss_isp_buf *buf =
+		container_of(vbuf, struct camss_isp_buf, vb);
+	struct camss_isp_bufq_entry *entry = &bufq->entries[queue_idx];
+	unsigned long flags;
+
+	spin_lock_irqsave(&entry->rdy_spinlock, flags);
+	list_add_tail(&buf->list, &entry->rdy_queue);
+	entry->num_rdy++;
+	spin_unlock_irqrestore(&entry->rdy_spinlock, flags);
+}
+EXPORT_SYMBOL_GPL(camss_isp_bufq_queue);
+
+struct vb2_v4l2_buffer *camss_isp_bufq_next(struct camss_isp_bufq *bufq, unsigned int queue_idx)
+{
+	struct camss_isp_bufq_entry *entry = &bufq->entries[queue_idx];
+	struct camss_isp_buf *buf;
+	unsigned long flags;
+
+	spin_lock_irqsave(&entry->rdy_spinlock, flags);
+	buf = list_first_entry_or_null(&entry->rdy_queue,
+				       struct camss_isp_buf, list);
+	spin_unlock_irqrestore(&entry->rdy_spinlock, flags);
+
+	return buf ? &buf->vb : NULL;
+}
+EXPORT_SYMBOL_GPL(camss_isp_bufq_next);
+
+struct vb2_v4l2_buffer *camss_isp_bufq_remove(struct camss_isp_bufq *bufq, unsigned int queue_idx)
+{
+	struct camss_isp_bufq_entry *entry = &bufq->entries[queue_idx];
+	struct camss_isp_buf *buf;
+	unsigned long flags;
+
+	spin_lock_irqsave(&entry->rdy_spinlock, flags);
+	buf = list_first_entry_or_null(&entry->rdy_queue,
+				       struct camss_isp_buf, list);
+	if (buf) {
+		list_del(&buf->list);
+		entry->num_rdy--;
+	}
+	spin_unlock_irqrestore(&entry->rdy_spinlock, flags);
+
+	return buf ? &buf->vb : NULL;
+}
+EXPORT_SYMBOL_GPL(camss_isp_bufq_remove);
+
+void camss_isp_bufq_drain(struct camss_isp_bufq *bufq, unsigned int queue_idx,
+			  enum vb2_buffer_state state)
+{
+	struct vb2_v4l2_buffer *vbuf;
+
+	while ((vbuf = camss_isp_bufq_remove(bufq, queue_idx)))
+		camss_isp_buf_done(vbuf, state);
+}
+EXPORT_SYMBOL_GPL(camss_isp_bufq_drain);
+
+MODULE_DESCRIPTION("CAMSS ISP per-queue ready-buffer FIFO");
+MODULE_LICENSE("GPL");
diff --git a/drivers/media/platform/qcom/camss/camss-isp-bufq.h b/drivers/media/platform/qcom/camss/camss-isp-bufq.h
new file mode 100644
index 0000000000000000000000000000000000000000..1a8bc7b112a1b039233cfc7be573f1f40fcda7c9
--- /dev/null
+++ b/drivers/media/platform/qcom/camss/camss-isp-bufq.h
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * camss-isp-bufq.h
+ *
+ * CAMSS ISP per-queue ready-buffer FIFO.
+ *
+ * Provides N spinlock-protected FIFO lists of ready vb2 buffers, one per
+ * queue index.  Drivers call these helpers from their vb2 ops and job
+ * completion paths.
+ *
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#ifndef CAMSS_ISP_BUFQ_H
+#define CAMSS_ISP_BUFQ_H
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <media/videobuf2-v4l2.h>
+
+/**
+ * struct camss_isp_buf - vb2 buffer wrapper
+ *
+ * Use as vb2_queue.buf_struct_size so buffers can be placed on the
+ * ready lists managed by camss_isp_bufq.
+ *
+ * @vb:   The vb2 V4L2 buffer — must be first.
+ * @list: Entry in the per-queue ready list.
+ */
+struct camss_isp_buf {
+	struct vb2_v4l2_buffer	vb;	/* must be first */
+	struct list_head	list;
+};
+
+/**
+ * struct camss_isp_bufq_entry - per-queue ready-buffer state (opaque)
+ */
+struct camss_isp_bufq_entry {
+	struct list_head	rdy_queue;
+	spinlock_t		rdy_spinlock;
+	u32			num_rdy;
+};
+
+/**
+ * struct camss_isp_bufq - multi-queue ready-buffer state
+ *
+ * Allocate with camss_isp_bufq_init(), free with camss_isp_bufq_release().
+ *
+ * @num_queues: Number of entries in @entries.
+ * @entries:    Per-queue state; flexible array.
+ */
+struct camss_isp_bufq {
+	unsigned int			num_queues;
+	struct camss_isp_bufq_entry	entries[] __counted_by(num_queues);
+};
+
+/**
+ * camss_isp_bufq_init() - allocate a multi-queue ready-buffer state
+ * @num_queues: number of per-queue FIFO lists to create
+ *
+ * Returns a pointer to the new bufq or ERR_PTR on allocation failure.
+ */
+struct camss_isp_bufq *camss_isp_bufq_init(unsigned int num_queues);
+
+/**
+ * camss_isp_bufq_release() - free a bufq allocated with camss_isp_bufq_init()
+ * @bufq: bufq to free
+ */
+void camss_isp_bufq_release(struct camss_isp_bufq *bufq);
+
+/**
+ * camss_isp_bufq_queue() - append a buffer to the ready list for @queue_idx
+ * @bufq:      target bufq
+ * @queue_idx: queue index (must be < bufq->num_queues)
+ * @vbuf:      buffer to enqueue; must be embedded in a &struct camss_isp_buf
+ */
+void camss_isp_bufq_queue(struct camss_isp_bufq *bufq, unsigned int queue_idx,
+			   struct vb2_v4l2_buffer *vbuf);
+
+/**
+ * camss_isp_bufq_next() - peek at the head of the ready list without removing
+ * @bufq:      target bufq
+ * @queue_idx: queue index
+ *
+ * Returns the head buffer or NULL if the list is empty.
+ */
+struct vb2_v4l2_buffer *camss_isp_bufq_next(struct camss_isp_bufq *bufq,
+					     unsigned int queue_idx);
+
+/**
+ * camss_isp_bufq_remove() - dequeue and return the head of the ready list
+ * @bufq:      target bufq
+ * @queue_idx: queue index
+ *
+ * Returns the dequeued buffer or NULL if the list is empty.
+ */
+struct vb2_v4l2_buffer *camss_isp_bufq_remove(struct camss_isp_bufq *bufq,
+					       unsigned int queue_idx);
+
+/**
+ * camss_isp_bufq_drain() - return all ready buffers with the given state
+ * @bufq:      target bufq
+ * @queue_idx: queue index
+ * @state:     vb2 state to pass to vb2_buffer_done() for each buffer
+ */
+void camss_isp_bufq_drain(struct camss_isp_bufq *bufq, unsigned int queue_idx,
+			   enum vb2_buffer_state state);
+
+static inline u32 camss_isp_bufq_num_ready(struct camss_isp_bufq *bufq,
+					    unsigned int queue_idx)
+{
+	return bufq->entries[queue_idx].num_rdy;
+}
+
+static inline void camss_isp_buf_done(struct vb2_v4l2_buffer *vbuf,
+				       enum vb2_buffer_state state)
+{
+	vb2_buffer_done(&vbuf->vb2_buf, state);
+}
+
+#endif /* CAMSS_ISP_BUFQ_H */

-- 
2.34.1