drm/imagination: Implement job submission and scheduling

Implement job submission ioctl. Job scheduling is implemented using
drm_sched.

Jobs are submitted in a stream format. This is intended to allow the UAPI
data format to be independent of the actual FWIF structures in use, which
vary depending on the GPU in use.

The stream formats are documented at:
https://gitlab.freedesktop.org/mesa/mesa/-/blob/f8d2b42ae65c2f16f36a43e0ae39d288431e4263/src/imagination/csbgen/rogue_kmd_stream.xml

Changes since v8:
- Updated for upstreamed DRM scheduler changes
- Removed workaround code for the pending_list previously being updated
  after run_job() returned
- Fixed null deref in pvr_queue_cleanup_fw_context() for bad stream ptr
  given to create_context ioctl
- Corrected license identifiers

Changes since v7:
- Updated for v8 "DRM scheduler changes for XE" patchset

Changes since v6:
- Fix fence handling in pvr_sync_signal_array_add()
- Add handling for SUBMIT_JOB_FRAG_CMD_DISABLE_PIXELMERGE flag
- Fix missing dma_resv locking in job submit path

Changes since v5:
- Fix leak in job creation error path

Changes since v4:
- Use a regular workqueue for job scheduling

Changes since v3:
- Support partial render jobs
- Add job timeout handler
- Split sync handling out of job code
- Use drm_dev_{enter,exit}

Changes since v2:
- Use drm_sched for job scheduling

Co-developed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Co-developed-by: Donald Robson <donald.robson@imgtec.com>
Signed-off-by: Donald Robson <donald.robson@imgtec.com>
Signed-off-by: Sarah Walker <sarah.walker@imgtec.com>
Link: https://lore.kernel.org/r/c98dab7a5f5fb891fbed7e4990d19b5d13964365.1700668843.git.donald.robson@imgtec.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>

1 files changed, 788 insertions, 0 deletions

diff --git a/drivers/gpu/drm/imagination/pvr_job.c b/drivers/gpu/drm/imagination/pvr_job.c
new file mode 100644
index 000000000000..9d0812710295
--- /dev/null
+++ b/drivers/gpu/drm/imagination/pvr_job.c
@@ -0,0 +1,788 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/* Copyright (c) 2023 Imagination Technologies Ltd. */
+
+#include "pvr_context.h"
+#include "pvr_device.h"
+#include "pvr_drv.h"
+#include "pvr_gem.h"
+#include "pvr_hwrt.h"
+#include "pvr_job.h"
+#include "pvr_mmu.h"
+#include "pvr_power.h"
+#include "pvr_rogue_fwif.h"
+#include "pvr_rogue_fwif_client.h"
+#include "pvr_stream.h"
+#include "pvr_stream_defs.h"
+#include "pvr_sync.h"
+
+#include <drm/drm_exec.h>
+#include <drm/drm_gem.h>
+#include <linux/types.h>
+#include <uapi/drm/pvr_drm.h>
+
+static void pvr_job_release(struct kref *kref)
+{
+	struct pvr_job *job = container_of(kref, struct pvr_job, ref_count);
+
+	xa_erase(&job->pvr_dev->job_ids, job->id);
+
+	pvr_hwrt_data_put(job->hwrt);
+	pvr_context_put(job->ctx);
+
+	WARN_ON(job->paired_job);
+
+	pvr_queue_job_cleanup(job);
+	pvr_job_release_pm_ref(job);
+
+	kfree(job->cmd);
+	kfree(job);
+}
+
+/**
+ * pvr_job_put() - Release reference on job
+ * @job: Target job.
+ */
+void
+pvr_job_put(struct pvr_job *job)
+{
+	if (job)
+		kref_put(&job->ref_count, pvr_job_release);
+}
+
+/**
+ * pvr_job_process_stream() - Build job FW structure from stream
+ * @pvr_dev: Device pointer.
+ * @cmd_defs: Stream definition.
+ * @stream: Pointer to command stream.
+ * @stream_size: Size of command stream, in bytes.
+ * @job: Pointer to job.
+ *
+ * Caller is responsible for freeing the output structure.
+ *
+ * Returns:
+ *  * 0 on success,
+ *  * -%ENOMEM on out of memory, or
+ *  * -%EINVAL on malformed stream.
+ */
+static int
+pvr_job_process_stream(struct pvr_device *pvr_dev, const struct pvr_stream_cmd_defs *cmd_defs,
+		       void *stream, u32 stream_size, struct pvr_job *job)
+{
+	int err;
+
+	job->cmd = kzalloc(cmd_defs->dest_size, GFP_KERNEL);
+	if (!job->cmd)
+		return -ENOMEM;
+
+	job->cmd_len = cmd_defs->dest_size;
+
+	err = pvr_stream_process(pvr_dev, cmd_defs, stream, stream_size, job->cmd);
+	if (err)
+		kfree(job->cmd);
+
+	return err;
+}
+
+static int pvr_fw_cmd_init(struct pvr_device *pvr_dev, struct pvr_job *job,
+			   const struct pvr_stream_cmd_defs *stream_def,
+			   u64 stream_userptr, u32 stream_len)
+{
+	void *stream;
+	int err;
+
+	stream = kzalloc(stream_len, GFP_KERNEL);
+	if (!stream)
+		return -ENOMEM;
+
+	if (copy_from_user(stream, u64_to_user_ptr(stream_userptr), stream_len)) {
+		err = -EFAULT;
+		goto err_free_stream;
+	}
+
+	err = pvr_job_process_stream(pvr_dev, stream_def, stream, stream_len, job);
+
+err_free_stream:
+	kfree(stream);
+
+	return err;
+}
+
+static u32
+convert_geom_flags(u32 in_flags)
+{
+	u32 out_flags = 0;
+
+	if (in_flags & DRM_PVR_SUBMIT_JOB_GEOM_CMD_FIRST)
+		out_flags |= ROGUE_GEOM_FLAGS_FIRSTKICK;
+	if (in_flags & DRM_PVR_SUBMIT_JOB_GEOM_CMD_LAST)
+		out_flags |= ROGUE_GEOM_FLAGS_LASTKICK;
+	if (in_flags & DRM_PVR_SUBMIT_JOB_GEOM_CMD_SINGLE_CORE)
+		out_flags |= ROGUE_GEOM_FLAGS_SINGLE_CORE;
+
+	return out_flags;
+}
+
+static u32
+convert_frag_flags(u32 in_flags)
+{
+	u32 out_flags = 0;
+
+	if (in_flags & DRM_PVR_SUBMIT_JOB_FRAG_CMD_SINGLE_CORE)
+		out_flags |= ROGUE_FRAG_FLAGS_SINGLE_CORE;
+	if (in_flags & DRM_PVR_SUBMIT_JOB_FRAG_CMD_DEPTHBUFFER)
+		out_flags |= ROGUE_FRAG_FLAGS_DEPTHBUFFER;
+	if (in_flags & DRM_PVR_SUBMIT_JOB_FRAG_CMD_STENCILBUFFER)
+		out_flags |= ROGUE_FRAG_FLAGS_STENCILBUFFER;
+	if (in_flags & DRM_PVR_SUBMIT_JOB_FRAG_CMD_PREVENT_CDM_OVERLAP)
+		out_flags |= ROGUE_FRAG_FLAGS_PREVENT_CDM_OVERLAP;
+	if (in_flags & DRM_PVR_SUBMIT_JOB_FRAG_CMD_SCRATCHBUFFER)
+		out_flags |= ROGUE_FRAG_FLAGS_SCRATCHBUFFER;
+	if (in_flags & DRM_PVR_SUBMIT_JOB_FRAG_CMD_GET_VIS_RESULTS)
+		out_flags |= ROGUE_FRAG_FLAGS_GET_VIS_RESULTS;
+	if (in_flags & DRM_PVR_SUBMIT_JOB_FRAG_CMD_DISABLE_PIXELMERGE)
+		out_flags |= ROGUE_FRAG_FLAGS_DISABLE_PIXELMERGE;
+
+	return out_flags;
+}
+
+static int
+pvr_geom_job_fw_cmd_init(struct pvr_job *job,
+			 struct drm_pvr_job *args)
+{
+	struct rogue_fwif_cmd_geom *cmd;
+	int err;
+
+	if (args->flags & ~DRM_PVR_SUBMIT_JOB_GEOM_CMD_FLAGS_MASK)
+		return -EINVAL;
+
+	if (job->ctx->type != DRM_PVR_CTX_TYPE_RENDER)
+		return -EINVAL;
+
+	if (!job->hwrt)
+		return -EINVAL;
+
+	job->fw_ccb_cmd_type = ROGUE_FWIF_CCB_CMD_TYPE_GEOM;
+	err = pvr_fw_cmd_init(job->pvr_dev, job, &pvr_cmd_geom_stream,
+			      args->cmd_stream, args->cmd_stream_len);
+	if (err)
+		return err;
+
+	cmd = job->cmd;
+	cmd->cmd_shared.cmn.frame_num = 0;
+	cmd->flags = convert_geom_flags(args->flags);
+	pvr_fw_object_get_fw_addr(job->hwrt->fw_obj, &cmd->cmd_shared.hwrt_data_fw_addr);
+	return 0;
+}
+
+static int
+pvr_frag_job_fw_cmd_init(struct pvr_job *job,
+			 struct drm_pvr_job *args)
+{
+	struct rogue_fwif_cmd_frag *cmd;
+	int err;
+
+	if (args->flags & ~DRM_PVR_SUBMIT_JOB_FRAG_CMD_FLAGS_MASK)
+		return -EINVAL;
+
+	if (job->ctx->type != DRM_PVR_CTX_TYPE_RENDER)
+		return -EINVAL;
+
+	if (!job->hwrt)
+		return -EINVAL;
+
+	job->fw_ccb_cmd_type = (args->flags & DRM_PVR_SUBMIT_JOB_FRAG_CMD_PARTIAL_RENDER) ?
+			       ROGUE_FWIF_CCB_CMD_TYPE_FRAG_PR :
+			       ROGUE_FWIF_CCB_CMD_TYPE_FRAG;
+	err = pvr_fw_cmd_init(job->pvr_dev, job, &pvr_cmd_frag_stream,
+			      args->cmd_stream, args->cmd_stream_len);
+	if (err)
+		return err;
+
+	cmd = job->cmd;
+	cmd->cmd_shared.cmn.frame_num = 0;
+	cmd->flags = convert_frag_flags(args->flags);
+	pvr_fw_object_get_fw_addr(job->hwrt->fw_obj, &cmd->cmd_shared.hwrt_data_fw_addr);
+	return 0;
+}
+
+static u32
+convert_compute_flags(u32 in_flags)
+{
+	u32 out_flags = 0;
+
+	if (in_flags & DRM_PVR_SUBMIT_JOB_COMPUTE_CMD_PREVENT_ALL_OVERLAP)
+		out_flags |= ROGUE_COMPUTE_FLAG_PREVENT_ALL_OVERLAP;
+	if (in_flags & DRM_PVR_SUBMIT_JOB_COMPUTE_CMD_SINGLE_CORE)
+		out_flags |= ROGUE_COMPUTE_FLAG_SINGLE_CORE;
+
+	return out_flags;
+}
+
+static int
+pvr_compute_job_fw_cmd_init(struct pvr_job *job,
+			    struct drm_pvr_job *args)
+{
+	struct rogue_fwif_cmd_compute *cmd;
+	int err;
+
+	if (args->flags & ~DRM_PVR_SUBMIT_JOB_COMPUTE_CMD_FLAGS_MASK)
+		return -EINVAL;
+
+	if (job->ctx->type != DRM_PVR_CTX_TYPE_COMPUTE)
+		return -EINVAL;
+
+	job->fw_ccb_cmd_type = ROGUE_FWIF_CCB_CMD_TYPE_CDM;
+	err = pvr_fw_cmd_init(job->pvr_dev, job, &pvr_cmd_compute_stream,
+			      args->cmd_stream, args->cmd_stream_len);
+	if (err)
+		return err;
+
+	cmd = job->cmd;
+	cmd->common.frame_num = 0;
+	cmd->flags = convert_compute_flags(args->flags);
+	return 0;
+}
+
+static u32
+convert_transfer_flags(u32 in_flags)
+{
+	u32 out_flags = 0;
+
+	if (in_flags & DRM_PVR_SUBMIT_JOB_TRANSFER_CMD_SINGLE_CORE)
+		out_flags |= ROGUE_TRANSFER_FLAGS_SINGLE_CORE;
+
+	return out_flags;
+}
+
+static int
+pvr_transfer_job_fw_cmd_init(struct pvr_job *job,
+			     struct drm_pvr_job *args)
+{
+	struct rogue_fwif_cmd_transfer *cmd;
+	int err;
+
+	if (args->flags & ~DRM_PVR_SUBMIT_JOB_TRANSFER_CMD_FLAGS_MASK)
+		return -EINVAL;
+
+	if (job->ctx->type != DRM_PVR_CTX_TYPE_TRANSFER_FRAG)
+		return -EINVAL;
+
+	job->fw_ccb_cmd_type = ROGUE_FWIF_CCB_CMD_TYPE_TQ_3D;
+	err = pvr_fw_cmd_init(job->pvr_dev, job, &pvr_cmd_transfer_stream,
+			      args->cmd_stream, args->cmd_stream_len);
+	if (err)
+		return err;
+
+	cmd = job->cmd;
+	cmd->common.frame_num = 0;
+	cmd->flags = convert_transfer_flags(args->flags);
+	return 0;
+}
+
+static int
+pvr_job_fw_cmd_init(struct pvr_job *job,
+		    struct drm_pvr_job *args)
+{
+	switch (args->type) {
+	case DRM_PVR_JOB_TYPE_GEOMETRY:
+		return pvr_geom_job_fw_cmd_init(job, args);
+
+	case DRM_PVR_JOB_TYPE_FRAGMENT:
+		return pvr_frag_job_fw_cmd_init(job, args);
+
+	case DRM_PVR_JOB_TYPE_COMPUTE:
+		return pvr_compute_job_fw_cmd_init(job, args);
+
+	case DRM_PVR_JOB_TYPE_TRANSFER_FRAG:
+		return pvr_transfer_job_fw_cmd_init(job, args);
+
+	default:
+		return -EINVAL;
+	}
+}
+
+/**
+ * struct pvr_job_data - Helper container for pairing jobs with the
+ * sync_ops supplied for them by the user.
+ */
+struct pvr_job_data {
+	/** @job: Pointer to the job. */
+	struct pvr_job *job;
+
+	/** @sync_ops: Pointer to the sync_ops associated with @job. */
+	struct drm_pvr_sync_op *sync_ops;
+
+	/** @sync_op_count: Number of members of @sync_ops. */
+	u32 sync_op_count;
+};
+
+/**
+ * prepare_job_syncs() - Prepare all sync objects for a single job.
+ * @pvr_file: PowerVR file.
+ * @job_data: Precreated job and sync_ops array.
+ * @signal_array: xarray to receive signal sync objects.
+ *
+ * Returns:
+ *  * 0 on success, or
+ *  * Any error code returned by pvr_sync_signal_array_collect_ops(),
+ *    pvr_sync_add_deps_to_job(), drm_sched_job_add_resv_dependencies() or
+ *    pvr_sync_signal_array_update_fences().
+ */
+static int
+prepare_job_syncs(struct pvr_file *pvr_file,
+		  struct pvr_job_data *job_data,
+		  struct xarray *signal_array)
+{
+	struct dma_fence *done_fence;
+	int err = pvr_sync_signal_array_collect_ops(signal_array,
+						    from_pvr_file(pvr_file),
+						    job_data->sync_op_count,
+						    job_data->sync_ops);
+
+	if (err)
+		return err;
+
+	err = pvr_sync_add_deps_to_job(pvr_file, &job_data->job->base,
+				       job_data->sync_op_count,
+				       job_data->sync_ops, signal_array);
+	if (err)
+		return err;
+
+	if (job_data->job->hwrt) {
+		/* The geometry job writes the HWRT region headers, which are
+		 * then read by the fragment job.
+		 */
+		struct drm_gem_object *obj =
+			gem_from_pvr_gem(job_data->job->hwrt->fw_obj->gem);
+		enum dma_resv_usage usage =
+			dma_resv_usage_rw(job_data->job->type ==
+					  DRM_PVR_JOB_TYPE_GEOMETRY);
+
+		dma_resv_lock(obj->resv, NULL);
+		err = drm_sched_job_add_resv_dependencies(&job_data->job->base,
+							  obj->resv, usage);
+		dma_resv_unlock(obj->resv);
+		if (err)
+			return err;
+	}
+
+	/* We need to arm the job to get the job done fence. */
+	done_fence = pvr_queue_job_arm(job_data->job);
+
+	err = pvr_sync_signal_array_update_fences(signal_array,
+						  job_data->sync_op_count,
+						  job_data->sync_ops,
+						  done_fence);
+	return err;
+}
+
+/**
+ * prepare_job_syncs_for_each() - Prepare all sync objects for an array of jobs.
+ * @file: PowerVR file.
+ * @job_data: Array of precreated jobs and their sync_ops.
+ * @job_count: Number of jobs.
+ * @signal_array: xarray to receive signal sync objects.
+ *
+ * Returns:
+ *  * 0 on success, or
+ *  * Any error code returned by pvr_vm_bind_job_prepare_syncs().
+ */
+static int
+prepare_job_syncs_for_each(struct pvr_file *pvr_file,
+			   struct pvr_job_data *job_data,
+			   u32 *job_count,
+			   struct xarray *signal_array)
+{
+	for (u32 i = 0; i < *job_count; i++) {
+		int err = prepare_job_syncs(pvr_file, &job_data[i],
+					    signal_array);
+
+		if (err) {
+			*job_count = i;
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static struct pvr_job *
+create_job(struct pvr_device *pvr_dev,
+	   struct pvr_file *pvr_file,
+	   struct drm_pvr_job *args)
+{
+	struct pvr_job *job = NULL;
+	int err;
+
+	if (!args->cmd_stream || !args->cmd_stream_len)
+		return ERR_PTR(-EINVAL);
+
+	if (args->type != DRM_PVR_JOB_TYPE_GEOMETRY &&
+	    args->type != DRM_PVR_JOB_TYPE_FRAGMENT &&
+	    (args->hwrt.set_handle || args->hwrt.data_index))
+		return ERR_PTR(-EINVAL);
+
+	job = kzalloc(sizeof(*job), GFP_KERNEL);
+	if (!job)
+		return ERR_PTR(-ENOMEM);
+
+	kref_init(&job->ref_count);
+	job->type = args->type;
+	job->pvr_dev = pvr_dev;
+
+	err = xa_alloc(&pvr_dev->job_ids, &job->id, job, xa_limit_32b, GFP_KERNEL);
+	if (err)
+		goto err_put_job;
+
+	job->ctx = pvr_context_lookup(pvr_file, args->context_handle);
+	if (!job->ctx) {
+		err = -EINVAL;
+		goto err_put_job;
+	}
+
+	if (args->hwrt.set_handle) {
+		job->hwrt = pvr_hwrt_data_lookup(pvr_file, args->hwrt.set_handle,
+						 args->hwrt.data_index);
+		if (!job->hwrt) {
+			err = -EINVAL;
+			goto err_put_job;
+		}
+	}
+
+	err = pvr_job_fw_cmd_init(job, args);
+	if (err)
+		goto err_put_job;
+
+	err = pvr_queue_job_init(job);
+	if (err)
+		goto err_put_job;
+
+	return job;
+
+err_put_job:
+	pvr_job_put(job);
+	return ERR_PTR(err);
+}
+
+/**
+ * pvr_job_data_fini() - Cleanup all allocs used to set up job submission.
+ * @job_data: Job data array.
+ * @job_count: Number of members of @job_data.
+ */
+static void
+pvr_job_data_fini(struct pvr_job_data *job_data, u32 job_count)
+{
+	for (u32 i = 0; i < job_count; i++) {
+		pvr_job_put(job_data[i].job);
+		kvfree(job_data[i].sync_ops);
+	}
+}
+
+/**
+ * pvr_job_data_init() - Init an array of created jobs, associating them with
+ * the appropriate sync_ops args, which will be copied in.
+ * @pvr_dev: Target PowerVR device.
+ * @pvr_file: Pointer to PowerVR file structure.
+ * @job_args: Job args array copied from user.
+ * @job_count: Number of members of @job_args.
+ * @job_data_out: Job data array.
+ */
+static int pvr_job_data_init(struct pvr_device *pvr_dev,
+			     struct pvr_file *pvr_file,
+			     struct drm_pvr_job *job_args,
+			     u32 *job_count,
+			     struct pvr_job_data *job_data_out)
+{
+	int err = 0, i = 0;
+
+	for (; i < *job_count; i++) {
+		job_data_out[i].job =
+			create_job(pvr_dev, pvr_file, &job_args[i]);
+		err = PTR_ERR_OR_ZERO(job_data_out[i].job);
+
+		if (err) {
+			*job_count = i;
+			job_data_out[i].job = NULL;
+			goto err_cleanup;
+		}
+
+		err = PVR_UOBJ_GET_ARRAY(job_data_out[i].sync_ops,
+					 &job_args[i].sync_ops);
+		if (err) {
+			*job_count = i;
+
+			/* Ensure the job created above is also cleaned up. */
+			i++;
+			goto err_cleanup;
+		}
+
+		job_data_out[i].sync_op_count = job_args[i].sync_ops.count;
+	}
+
+	return 0;
+
+err_cleanup:
+	pvr_job_data_fini(job_data_out, i);
+
+	return err;
+}
+
+static void
+push_jobs(struct pvr_job_data *job_data, u32 job_count)
+{
+	for (u32 i = 0; i < job_count; i++)
+		pvr_queue_job_push(job_data[i].job);
+}
+
+static int
+prepare_fw_obj_resv(struct drm_exec *exec, struct pvr_fw_object *fw_obj)
+{
+	return drm_exec_prepare_obj(exec, gem_from_pvr_gem(fw_obj->gem), 1);
+}
+
+static int
+jobs_lock_all_objs(struct drm_exec *exec, struct pvr_job_data *job_data,
+		   u32 job_count)
+{
+	for (u32 i = 0; i < job_count; i++) {
+		struct pvr_job *job = job_data[i].job;
+
+		/* Grab a lock on a the context, to guard against
+		 * concurrent submission to the same queue.
+		 */
+		int err = drm_exec_lock_obj(exec,
+					    gem_from_pvr_gem(job->ctx->fw_obj->gem));
+
+		if (err)
+			return err;
+
+		if (job->hwrt) {
+			err = prepare_fw_obj_resv(exec,
+						  job->hwrt->fw_obj);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+static int
+prepare_job_resvs_for_each(struct drm_exec *exec, struct pvr_job_data *job_data,
+			   u32 job_count)
+{
+	drm_exec_until_all_locked(exec) {
+		int err = jobs_lock_all_objs(exec, job_data, job_count);
+
+		drm_exec_retry_on_contention(exec);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static void
+update_job_resvs(struct pvr_job *job)
+{
+	if (job->hwrt) {
+		enum dma_resv_usage usage = job->type == DRM_PVR_JOB_TYPE_GEOMETRY ?
+					    DMA_RESV_USAGE_WRITE : DMA_RESV_USAGE_READ;
+		struct drm_gem_object *obj = gem_from_pvr_gem(job->hwrt->fw_obj->gem);
+
+		dma_resv_add_fence(obj->resv, &job->base.s_fence->finished, usage);
+	}
+}
+
+static void
+update_job_resvs_for_each(struct pvr_job_data *job_data, u32 job_count)
+{
+	for (u32 i = 0; i < job_count; i++)
+		update_job_resvs(job_data[i].job);
+}
+
+static bool can_combine_jobs(struct pvr_job *a, struct pvr_job *b)
+{
+	struct pvr_job *geom_job = a, *frag_job = b;
+	struct dma_fence *fence;
+	unsigned long index;
+
+	/* Geometry and fragment jobs can be combined if they are queued to the
+	 * same context and targeting the same HWRT.
+	 */
+	if (a->type != DRM_PVR_JOB_TYPE_GEOMETRY ||
+	    b->type != DRM_PVR_JOB_TYPE_FRAGMENT ||
+	    a->ctx != b->ctx ||
+	    a->hwrt != b->hwrt)
+		return false;
+
+	xa_for_each(&frag_job->base.dependencies, index, fence) {
+		/* We combine when we see an explicit geom -> frag dep. */
+		if (&geom_job->base.s_fence->scheduled == fence)
+			return true;
+	}
+
+	return false;
+}
+
+static struct dma_fence *
+get_last_queued_job_scheduled_fence(struct pvr_queue *queue,
+				    struct pvr_job_data *job_data,
+				    u32 cur_job_pos)
+{
+	/* We iterate over the current job array in reverse order to grab the
+	 * last to-be-queued job targeting the same queue.
+	 */
+	for (u32 i = cur_job_pos; i > 0; i--) {
+		struct pvr_job *job = job_data[i - 1].job;
+
+		if (job->ctx == queue->ctx && job->type == queue->type)
+			return dma_fence_get(&job->base.s_fence->scheduled);
+	}
+
+	/* If we didn't find any, we just return the last queued job scheduled
+	 * fence attached to the queue.
+	 */
+	return dma_fence_get(queue->last_queued_job_scheduled_fence);
+}
+
+static int
+pvr_jobs_link_geom_frag(struct pvr_job_data *job_data, u32 *job_count)
+{
+	for (u32 i = 0; i < *job_count - 1; i++) {
+		struct pvr_job *geom_job = job_data[i].job;
+		struct pvr_job *frag_job = job_data[i + 1].job;
+		struct pvr_queue *frag_queue;
+		struct dma_fence *f;
+
+		if (!can_combine_jobs(job_data[i].job, job_data[i + 1].job))
+			continue;
+
+		/* The fragment job will be submitted by the geometry queue. We
+		 * need to make sure it comes after all the other fragment jobs
+		 * queued before it.
+		 */
+		frag_queue = pvr_context_get_queue_for_job(frag_job->ctx,
+							   frag_job->type);
+		f = get_last_queued_job_scheduled_fence(frag_queue, job_data,
+							i);
+		if (f) {
+			int err = drm_sched_job_add_dependency(&geom_job->base,
+							       f);
+			if (err) {
+				*job_count = i;
+				return err;
+			}
+		}
+
+		/* The KCCB slot will be reserved by the geometry job, so we can
+		 * drop the KCCB fence on the fragment job.
+		 */
+		pvr_kccb_fence_put(frag_job->kccb_fence);
+		frag_job->kccb_fence = NULL;
+
+		geom_job->paired_job = frag_job;
+		frag_job->paired_job = geom_job;
+
+		/* Skip the fragment job we just paired to the geometry job. */
+		i++;
+	}
+
+	return 0;
+}
+
+/**
+ * pvr_submit_jobs() - Submit jobs to the GPU
+ * @pvr_dev: Target PowerVR device.
+ * @pvr_file: Pointer to PowerVR file structure.
+ * @args: Ioctl args.
+ * @job_count: Number of jobs in @jobs_args. On error this will be updated
+ * with the index into @jobs_args where the error occurred.
+ *
+ * This initial implementation is entirely synchronous; on return the GPU will
+ * be idle. This will not be the case for future implementations.
+ *
+ * Returns:
+ *  * 0 on success,
+ *  * -%EFAULT if arguments can not be copied from user space, or
+ *  * -%EINVAL on invalid arguments, or
+ *  * Any other error.
+ */
+int
+pvr_submit_jobs(struct pvr_device *pvr_dev, struct pvr_file *pvr_file,
+		struct drm_pvr_ioctl_submit_jobs_args *args)
+{
+	struct pvr_job_data *job_data = NULL;
+	struct drm_pvr_job *job_args;
+	struct xarray signal_array;
+	u32 jobs_alloced = 0;
+	struct drm_exec exec;
+	int err;
+
+	if (!args->jobs.count)
+		return -EINVAL;
+
+	err = PVR_UOBJ_GET_ARRAY(job_args, &args->jobs);
+	if (err)
+		return err;
+
+	job_data = kvmalloc_array(args->jobs.count, sizeof(*job_data),
+				  GFP_KERNEL | __GFP_ZERO);
+	if (!job_data) {
+		err = -ENOMEM;
+		goto out_free;
+	}
+
+	err = pvr_job_data_init(pvr_dev, pvr_file, job_args, &args->jobs.count,
+				job_data);
+	if (err)
+		goto out_free;
+
+	jobs_alloced = args->jobs.count;
+
+	/*
+	 * Flush MMU if needed - this has been deferred until now to avoid
+	 * overuse of this expensive operation.
+	 */
+	err = pvr_mmu_flush_exec(pvr_dev, false);
+	if (err)
+		goto out_job_data_cleanup;
+
+	drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT | DRM_EXEC_IGNORE_DUPLICATES);
+
+	xa_init_flags(&signal_array, XA_FLAGS_ALLOC);
+
+	err = prepare_job_syncs_for_each(pvr_file, job_data, &args->jobs.count,
+					 &signal_array);
+	if (err)
+		goto out_exec_fini;
+
+	err = prepare_job_resvs_for_each(&exec, job_data, args->jobs.count);
+	if (err)
+		goto out_exec_fini;
+
+	err = pvr_jobs_link_geom_frag(job_data, &args->jobs.count);
+	if (err)
+		goto out_exec_fini;
+
+	/* Anything after that point must succeed because we start exposing job
+	 * finished fences to the outside world.
+	 */
+	update_job_resvs_for_each(job_data, args->jobs.count);
+	push_jobs(job_data, args->jobs.count);
+	pvr_sync_signal_array_push_fences(&signal_array);
+	err = 0;
+
+out_exec_fini:
+	drm_exec_fini(&exec);
+	pvr_sync_signal_array_cleanup(&signal_array);
+
+out_job_data_cleanup:
+	pvr_job_data_fini(job_data, jobs_alloced);
+
+out_free:
+	kvfree(job_data);
+	kvfree(job_args);
+
+	return err;
+}