virtio_console: Add support for remoteproc serial (1b637046) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/char/virtio_console.c

+169 −23

Original line number	Diff line number	Diff line
		@@ -37,8 +37,12 @@
		#include <linux/wait.h>
		#include <linux/workqueue.h>
		#include <linux/module.h>
		#include <linux/dma-mapping.h>
		#include <linux/kconfig.h>
		#include "../tty/hvc/hvc_console.h"

		#define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)

		/*
		* This is a global struct for storing common data for all the devices
		* this driver handles.
		@@ -112,6 +116,15 @@ struct port_buffer {
		/* offset in the buf from which to consume data */
		size_t offset;

		/* DMA address of buffer */
		dma_addr_t dma;

		/* Device we got DMA memory from */
		struct device *dev;

		/* List of pending dma buffers to free */
		struct list_head list;

		/* If sgpages == 0 then buf is used */
		unsigned int sgpages;

		@@ -331,6 +344,11 @@ static bool is_console_port(struct port *port)
		return false;
		}

		static bool is_rproc_serial(const struct virtio_device *vdev)
		{
		return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
		}

		static inline bool use_multiport(struct ports_device *portdev)
		{
		/*
		@@ -342,11 +360,13 @@ static inline bool use_multiport(struct ports_device *portdev)
		return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
		}

		static void free_buf(struct port_buffer *buf)
		static DEFINE_SPINLOCK(dma_bufs_lock);
		static LIST_HEAD(pending_free_dma_bufs);

		static void free_buf(struct port_buffer *buf, bool can_sleep)
		{
		unsigned int i;

		kfree(buf->buf);
		for (i = 0; i < buf->sgpages; i++) {
		struct page *page = sg_page(&buf->sg[i]);
		if (!page)
		@@ -354,14 +374,57 @@ static void free_buf(struct port_buffer *buf)
		put_page(page);
		}

		if (!buf->dev) {
		kfree(buf->buf);
		} else if (is_rproc_enabled) {
		unsigned long flags;

		/* dma_free_coherent requires interrupts to be enabled. */
		if (!can_sleep) {
		/* queue up dma-buffers to be freed later */
		spin_lock_irqsave(&dma_bufs_lock, flags);
		list_add_tail(&buf->list, &pending_free_dma_bufs);
		spin_unlock_irqrestore(&dma_bufs_lock, flags);
		return;
		}
		dma_free_coherent(buf->dev, buf->size, buf->buf, buf->dma);

		/* Release device refcnt and allow it to be freed */
		put_device(buf->dev);
		}

		kfree(buf);
		}

		static void reclaim_dma_bufs(void)
		{
		unsigned long flags;
		struct port_buffer buf, tmp;
		LIST_HEAD(tmp_list);

		if (list_empty(&pending_free_dma_bufs))
		return;

		/* Create a copy of the pending_free_dma_bufs while holding the lock */
		spin_lock_irqsave(&dma_bufs_lock, flags);
		list_cut_position(&tmp_list, &pending_free_dma_bufs,
		pending_free_dma_bufs.prev);
		spin_unlock_irqrestore(&dma_bufs_lock, flags);

		/* Release the dma buffers, without irqs enabled */
		list_for_each_entry_safe(buf, tmp, &tmp_list, list) {
		list_del(&buf->list);
		free_buf(buf, true);
		}
		}

		static struct port_buffer alloc_buf(struct virtqueue vq, size_t buf_size,
		int pages)
		{
		struct port_buffer *buf;

		reclaim_dma_bufs();

		/*
		* Allocate buffer and the sg list. The sg list array is allocated
		* directly after the port_buffer struct.
		@@ -373,11 +436,34 @@ static struct port_buffer alloc_buf(struct virtqueue vq, size_t buf_size,

		buf->sgpages = pages;
		if (pages > 0) {
		buf->dev = NULL;
		buf->buf = NULL;
		return buf;
		}

		if (is_rproc_serial(vq->vdev)) {
		/*
		* Allocate DMA memory from ancestor. When a virtio
		* device is created by remoteproc, the DMA memory is
		* associated with the grandparent device:
		* vdev => rproc => platform-dev.
		* The code here would have been less quirky if
		* DMA_MEMORY_INCLUDES_CHILDREN had been supported
		* in dma-coherent.c
		*/
		if (!vq->vdev->dev.parent \|\| !vq->vdev->dev.parent->parent)
		goto free_buf;
		buf->dev = vq->vdev->dev.parent->parent;

		/* Increase device refcnt to avoid freeing it */
		get_device(buf->dev);
		buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma,
		GFP_KERNEL);
		} else {
		buf->dev = NULL;
		buf->buf = kmalloc(buf_size, GFP_KERNEL);
		}

		if (!buf->buf)
		goto free_buf;
		buf->len = 0;
		@@ -446,7 +532,7 @@ static void discard_port_data(struct port *port)
		port->stats.bytes_discarded += buf->len - buf->offset;
		if (add_inbuf(port->in_vq, buf) < 0) {
		err++;
		free_buf(buf);
		free_buf(buf, false);
		}
		port->inbuf = NULL;
		buf = get_inbuf(port);
		@@ -518,7 +604,7 @@ static void reclaim_consumed_buffers(struct port *port)
		return;
		}
		while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
		free_buf(buf);
		free_buf(buf, false);
		port->outvq_full = false;
		}
		}
		@@ -765,7 +851,7 @@ static ssize_t port_fops_write(struct file filp, const char __user ubuf,
		goto out;

		free_buf:
		free_buf(buf);
		free_buf(buf, true);
		out:
		return ret;
		}
		@@ -839,6 +925,15 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
		.u.data = &sgl,
		};

		/*
		* Rproc_serial does not yet support splice. To support splice
		* pipe_to_sg() must allocate dma-buffers and copy content from
		* regular pages to dma pages. And alloc_buf and free_buf must
		* support allocating and freeing such a list of dma-buffers.
		*/
		if (is_rproc_serial(port->out_vq->vdev))
		return -EINVAL;

		ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
		if (ret < 0)
		return ret;
		@@ -857,7 +952,7 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
		ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);

		if (unlikely(ret <= 0))
		kfree(sgl.sg);
		free_buf(buf, true);
		return ret;
		}

		@@ -906,6 +1001,7 @@ static int port_fops_release(struct inode inode, struct file filp)
		reclaim_consumed_buffers(port);
		spin_unlock_irq(&port->outvq_lock);

		reclaim_dma_bufs();
		/*
		* Locks aren't necessary here as a port can't be opened after
		* unplug, and if a port isn't unplugged, a kref would already
		@@ -1057,7 +1153,10 @@ static void resize_console(struct port *port)
		return;

		vdev = port->portdev->vdev;
		if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))

		/* Don't test F_SIZE at all if we're rproc: not a valid feature! */
		if (!is_rproc_serial(vdev) &&
		virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
		hvc_resize(port->cons.hvc, port->cons.ws);
		}

		@@ -1249,7 +1348,7 @@ static unsigned int fill_queue(struct virtqueue vq, spinlock_t lock)
		ret = add_inbuf(vq, buf);
		if (ret < 0) {
		spin_unlock_irq(lock);
		free_buf(buf);
		free_buf(buf, true);
		break;
		}
		nr_added_bufs++;
		@@ -1337,10 +1436,18 @@ static int add_port(struct ports_device *portdev, u32 id)
		goto free_device;
		}

		if (is_rproc_serial(port->portdev->vdev))
		/*
		* For rproc_serial assume remote processor is connected.
		* rproc_serial does not want the console port, only
		* the generic port implementation.
		*/
		port->host_connected = true;
		else if (!use_multiport(port->portdev)) {
		/*
		* If we're not using multiport support, this has to be a console port
		* If we're not using multiport support,
		* this has to be a console port.
		*/
		if (!use_multiport(port->portdev)) {
		err = init_port_console(port);
		if (err)
		goto free_inbufs;
		@@ -1373,7 +1480,7 @@ static int add_port(struct ports_device *portdev, u32 id)

		free_inbufs:
		while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
		free_buf(buf);
		free_buf(buf, true);
		free_device:
		device_destroy(pdrvdata.class, port->dev->devt);
		free_cdev:
		@@ -1415,11 +1522,11 @@ static void remove_port_data(struct port *port)

		/* Remove buffers we queued up for the Host to send us data in. */
		while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
		free_buf(buf);
		free_buf(buf, true);

		/* Free pending buffers from the out-queue. */
		while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
		free_buf(buf);
		free_buf(buf, true);
		}

		/*
		@@ -1621,7 +1728,7 @@ static void control_work_handler(struct work_struct *work)
		if (add_inbuf(portdev->c_ivq, buf) < 0) {
		dev_warn(&portdev->vdev->dev,
		"Error adding buffer to queue\n");
		free_buf(buf);
		free_buf(buf, false);
		}
		}
		spin_unlock(&portdev->cvq_lock);
		@@ -1817,10 +1924,10 @@ static void remove_controlq_data(struct ports_device *portdev)
		return;

		while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
		free_buf(buf);
		free_buf(buf, true);

		while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
		free_buf(buf);
		free_buf(buf, true);
		}

		/*
		@@ -1867,11 +1974,15 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)

		multiport = false;
		portdev->config.max_nr_ports = 1;
		if (virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,

		/* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
		if (!is_rproc_serial(vdev) &&
		virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
		offsetof(struct virtio_console_config,
		max_nr_ports),
		&portdev->config.max_nr_ports) == 0)
		&portdev->config.max_nr_ports) == 0) {
		multiport = true;
		}

		err = init_vqs(portdev);
		if (err < 0) {
		@@ -1981,6 +2092,16 @@ static unsigned int features[] = {
		VIRTIO_CONSOLE_F_MULTIPORT,
		};

		static struct virtio_device_id rproc_serial_id_table[] = {
		#if IS_ENABLED(CONFIG_REMOTEPROC)
		{ VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
		#endif
		{ 0 },
		};

		static unsigned int rproc_serial_features[] = {
		};

		#ifdef CONFIG_PM
		static int virtcons_freeze(struct virtio_device *vdev)
		{
		@@ -2065,6 +2186,20 @@ static struct virtio_driver virtio_console = {
		#endif
		};

		/*
		* virtio_rproc_serial refers to __devinit function which causes
		* section mismatch warnings. So use __refdata to silence warnings.
		*/
		static struct virtio_driver __refdata virtio_rproc_serial = {
		.feature_table = rproc_serial_features,
		.feature_table_size = ARRAY_SIZE(rproc_serial_features),
		.driver.name = "virtio_rproc_serial",
		.driver.owner = THIS_MODULE,
		.id_table = rproc_serial_id_table,
		.probe = virtcons_probe,
		.remove = virtcons_remove,
		};

		static int __init init(void)
		{
		int err;
		@@ -2089,7 +2224,15 @@ static int __init init(void)
		pr_err("Error %d registering virtio driver\n", err);
		goto free;
		}
		err = register_virtio_driver(&virtio_rproc_serial);
		if (err < 0) {
		pr_err("Error %d registering virtio rproc serial driver\n",
		err);
		goto unregister;
		}
		return 0;
		unregister:
		unregister_virtio_driver(&virtio_console);
		free:
		if (pdrvdata.debugfs_dir)
		debugfs_remove_recursive(pdrvdata.debugfs_dir);
		@@ -2099,7 +2242,10 @@ free:

		static void __exit fini(void)
		{
		reclaim_dma_bufs();

		unregister_virtio_driver(&virtio_console);
		unregister_virtio_driver(&virtio_rproc_serial);

		class_destroy(pdrvdata.class);
		if (pdrvdata.debugfs_dir)

include/uapi/linux/virtio_ids.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -37,5 +37,6 @@
		#define VIRTIO_ID_RPMSG 7 /* virtio remote processor messaging */
		#define VIRTIO_ID_SCSI 8 /* virtio scsi */
		#define VIRTIO_ID_9P 9 /* 9p virtio console */
		#define VIRTIO_ID_RPROC_SERIAL 11 /* virtio remoteproc serial link */

		#endif /* _LINUX_VIRTIO_IDS_H */