1 files changed, 160 insertions, 0 deletions

diff --git a/drivers/gpu/host1x/channel.c b/drivers/gpu/host1x/channel.c
new file mode 100644
index 000000000..2d0051d63
--- /dev/null
+++ b/drivers/gpu/host1x/channel.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Tegra host1x Channel
+ *
+ * Copyright (c) 2010-2013, NVIDIA Corporation.
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include "channel.h"
+#include "dev.h"
+#include "job.h"
+
+/* Constructor for the host1x device list */
+int host1x_channel_list_init(struct host1x_channel_list *chlist,
+			     unsigned int num_channels)
+{
+	chlist->channels = kcalloc(num_channels, sizeof(struct host1x_channel),
+				   GFP_KERNEL);
+	if (!chlist->channels)
+		return -ENOMEM;
+
+	chlist->allocated_channels = bitmap_zalloc(num_channels, GFP_KERNEL);
+	if (!chlist->allocated_channels) {
+		kfree(chlist->channels);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void host1x_channel_list_free(struct host1x_channel_list *chlist)
+{
+	bitmap_free(chlist->allocated_channels);
+	kfree(chlist->channels);
+}
+
+int host1x_job_submit(struct host1x_job *job)
+{
+	struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
+
+	return host1x_hw_channel_submit(host, job);
+}
+EXPORT_SYMBOL(host1x_job_submit);
+
+struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
+{
+	kref_get(&channel->refcount);
+
+	return channel;
+}
+EXPORT_SYMBOL(host1x_channel_get);
+
+/**
+ * host1x_channel_get_index() - Attempt to get channel reference by index
+ * @host: Host1x device object
+ * @index: Index of channel
+ *
+ * If channel number @index is currently allocated, increase its refcount
+ * and return a pointer to it. Otherwise, return NULL.
+ */
+struct host1x_channel *host1x_channel_get_index(struct host1x *host,
+						unsigned int index)
+{
+	struct host1x_channel *ch = &host->channel_list.channels[index];
+
+	if (!kref_get_unless_zero(&ch->refcount))
+		return NULL;
+
+	return ch;
+}
+
+void host1x_channel_stop(struct host1x_channel *channel)
+{
+	struct host1x *host = dev_get_drvdata(channel->dev->parent);
+
+	host1x_hw_cdma_stop(host, &channel->cdma);
+}
+EXPORT_SYMBOL(host1x_channel_stop);
+
+static void release_channel(struct kref *kref)
+{
+	struct host1x_channel *channel =
+		container_of(kref, struct host1x_channel, refcount);
+	struct host1x *host = dev_get_drvdata(channel->dev->parent);
+	struct host1x_channel_list *chlist = &host->channel_list;
+
+	host1x_hw_cdma_stop(host, &channel->cdma);
+	host1x_cdma_deinit(&channel->cdma);
+
+	clear_bit(channel->id, chlist->allocated_channels);
+}
+
+void host1x_channel_put(struct host1x_channel *channel)
+{
+	kref_put(&channel->refcount, release_channel);
+}
+EXPORT_SYMBOL(host1x_channel_put);
+
+static struct host1x_channel *acquire_unused_channel(struct host1x *host)
+{
+	struct host1x_channel_list *chlist = &host->channel_list;
+	unsigned int max_channels = host->info->nb_channels;
+	unsigned int index;
+
+	index = find_first_zero_bit(chlist->allocated_channels, max_channels);
+	if (index >= max_channels) {
+		dev_err(host->dev, "failed to find free channel\n");
+		return NULL;
+	}
+
+	chlist->channels[index].id = index;
+
+	set_bit(index, chlist->allocated_channels);
+
+	return &chlist->channels[index];
+}
+
+/**
+ * host1x_channel_request() - Allocate a channel
+ * @client: Host1x client this channel will be used to send commands to
+ *
+ * Allocates a new host1x channel for @client. May return NULL if CDMA
+ * initialization fails.
+ */
+struct host1x_channel *host1x_channel_request(struct host1x_client *client)
+{
+	struct host1x *host = dev_get_drvdata(client->dev->parent);
+	struct host1x_channel_list *chlist = &host->channel_list;
+	struct host1x_channel *channel;
+	int err;
+
+	channel = acquire_unused_channel(host);
+	if (!channel)
+		return NULL;
+
+	kref_init(&channel->refcount);
+	mutex_init(&channel->submitlock);
+	channel->client = client;
+	channel->dev = client->dev;
+
+	err = host1x_hw_channel_init(host, channel, channel->id);
+	if (err < 0)
+		goto fail;
+
+	err = host1x_cdma_init(&channel->cdma);
+	if (err < 0)
+		goto fail;
+
+	return channel;
+
+fail:
+	clear_bit(channel->id, chlist->allocated_channels);
+
+	dev_err(client->dev, "failed to initialize channel\n");
+
+	return NULL;
+}
+EXPORT_SYMBOL(host1x_channel_request);