diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/virtio_console.c | 192 |
1 files changed, 169 insertions, 23 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 548224686963..55a89a4ae42f 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -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; } - buf->buf = kmalloc(buf_size, GFP_KERNEL); + 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 we're not using multiport support, this has to be a console port - */ - if (!use_multiport(port->portdev)) { + 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. + */ 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, - offsetof(struct virtio_console_config, - max_nr_ports), - &portdev->config.max_nr_ports) == 0) + + /* 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) { 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) |