msm: camera: sync: Add support for dma fences

Add support to create, release, signal and import
a dma fence. When a sync object is imported for a dma fence
signal the dma fence when signaling the sync object with
appropriate status. This is achieved by implementing
generic fence scheme. The change also adds support
for batched fences.

CRs-Fixed: 3207212
Change-Id: I23fbc0992281cfee0303e213a30bce138ae7bdff
Signed-off-by: Karthik Anantha Ram <quic_kartanan@quicinc.com>

drivers/cam_sync/cam_sync_dma_fence.h

@@ -0,0 +1,178 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#ifndef __CAM_SYNC_DMA_FENCE_H__
+#define __CAM_SYNC_DMA_FENCE_H__
+
+#include <linux/dma-fence.h>
+#include <linux/spinlock_types.h>
+#include <linux/sync_file.h>
+#include <linux/file.h>
+#include <linux/bitmap.h>
+
+#include "cam_sync.h"
+#include "cam_debug_util.h"
+
+#define CAM_DMA_FENCE_MAX_FENCES  128
+#define CAM_DMA_FENCE_NAME_LEN    128
+
+/* DMA fence state */
+enum cam_dma_fence_state {
+	CAM_DMA_FENCE_STATE_INVALID,
+	CAM_DMA_FENCE_STATE_ACTIVE,
+	CAM_DMA_FENCE_STATE_SIGNALED,
+};
+
+/**
+ * struct cam_dma_fence_release_params - DMA release payload
+ *                     Based on the flag row_idx or fd is consumed
+ *
+ * @dma_row_idx      : DMA fence row idx
+ * @dma_fence_fd     : DMA fence fd
+ * @use_row_idx      : Use row idx
+ */
+struct cam_dma_fence_release_params {
+	union {
+		int32_t dma_row_idx;
+		int32_t dma_fence_fd;
+	} u;
+	bool use_row_idx;
+};
+
+/**
+ * struct cam_dma_fence_signal_sync_obj - DMA -> sync signal info
+ *                           Payload to signal sync on a dma fence
+ *                           being signaled
+ *
+ * @status                 : DMA fence status
+ * @fd                     : DMA fence fd if any
+ */
+struct cam_dma_fence_signal_sync_obj {
+	int32_t status;
+	int32_t fd;
+};
+
+/* DMA fence callback function type */
+typedef int (*cam_sync_callback_for_dma_fence)(int32_t sync_obj,
+	struct cam_dma_fence_signal_sync_obj *signal_sync_obj);
+
+/**
+ * struct cam_dma_fence_create_sync_obj_payload -
+ *                           Payload to create sync for a dma fence
+ *
+ * @dma_fence_row_idx      : DMA fence row idx
+ * @fd                     : DMA fence fd
+ * @sync_created_with_dma  : Set if dma fence and sync obj are being
+ *                           created in a single IOCTL call
+ */
+struct cam_dma_fence_create_sync_obj_payload {
+	int32_t dma_fence_row_idx;
+	int32_t fd;
+	bool    sync_created_with_dma;
+};
+
+/**
+ * @brief: Signal a dma fence fd [userspace API]
+ *
+ * @param signal_dma_fence: Info on DMA fence to be signaled
+ *
+ * @return Status of operation. Negative in case of error. Zero otherwise.
+ */
+int cam_dma_fence_signal_fd(
+	struct cam_dma_fence_signal *signal_dma_fence);
+
+/**
+ * @brief: Signal a dma fence when sync obj is signaled
+ *
+ * @param dma_fence_row_idx : DMA fence row idx
+ * @param signal_dma_fence  : Info on DMA fence to be signaled
+ *
+ * @return Status of operation. Negative in case of error. Zero otherwise.
+ */
+int cam_dma_fence_internal_signal(int32_t dma_fence_row_idx,
+	struct cam_dma_fence_signal *signal_dma_fence);
+
+/**
+ * @brief: Create a dma fence fd
+ *
+ * @param  name              : DMA fence name, optional param
+ *                             will accommodate names of length
+ *                             CAM_DMA_FENCE_NAME_LEN
+ * @output dma_fence_fd      : DMA fence fd
+ * @output dma_fence_row_idx : Row Idx corresponding to DMA fence in the table
+ *
+ * @return Status of operation. Negative in case of error. Zero otherwise.
+ */
+int cam_dma_fence_create_fd(
+	int32_t *dma_fence_fd, int32_t *dma_fence_row_idx, const char *name);
+
+/**
+ * @brief: Release a dma fence
+ *
+ * @param release_params : dma fence info to be released
+ *
+ * @return Status of operation. Negative in case of error. Zero otherwise.
+ */
+int cam_dma_fence_release(
+	struct cam_dma_fence_release_params *release_params);
+
+/**
+ * @brief: Gets the dma fence from a fd, increments refcnt
+ *
+ * @param  fd                : File descriptor
+ * @output dma_fence_row_idx : Row idx pertaining to this dma fence
+ *
+ * @return Status of operation. Error or valid fence.
+ */
+struct dma_fence *cam_dma_fence_get_fence_from_fd(int32_t fd,
+	int32_t *dma_fence_row_idx);
+
+/**
+ * @brief: DMA fence register cb
+ *
+ * @param sync_obj      : Sync object
+ * @param dma_fence_idx : DMA fence row idx
+ * @param sync_cb       : Sync object callback
+ *
+ * @return Status of operation. Negative in case of error. Zero otherwise.
+ */
+int cam_dma_fence_register_cb(int32_t *sync_obj,
+	int32_t *dma_fence_row_idx, cam_sync_callback_for_dma_fence sync_cb);
+
+/**
+ * @brief: get/put on dma fence
+ *
+ * @get_or_put              : True for get, false for put
+ * @param dma_fence_row_idx : Idx in the dma fence table pertaining to
+ *                            the dma fence on which get/put ref is invoked
+ *
+ * @return Status of operation. Negative in case of error. Zero otherwise.
+ */
+int cam_dma_fence_get_put_ref(bool get_or_put, int32_t dma_fence_row_idx);
+
+/**
+ * @brief: dma fence driver open
+ *
+ */
+void cam_dma_fence_open(void);
+
+/**
+ * @brief: dma fence driver close
+ *
+ */
+void cam_dma_fence_close(void);
+
+/**
+ * @brief: dma fence driver initialize
+ *
+ */
+int cam_dma_fence_driver_init(void);
+
+/**
+ * @brief: dma fence driver deinit
+ *
+ */
+void cam_dma_fence_driver_deinit(void);
+
+#endif /* __CAM_SYNC_DMA_FENCE_H__ */