| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Amit Shah | 5941 | 67.30% | 86 | 50.89% |
| Sjur Brændeland | 725 | 8.21% | 6 | 3.55% |
| Masami Hiramatsu | 713 | 8.08% | 4 | 2.37% |
| Michael S. Tsirkin | 507 | 5.74% | 16 | 9.47% |
| Rusty Russell | 380 | 4.30% | 13 | 7.69% |
| Christian Bornträger | 137 | 1.55% | 3 | 1.78% |
| Alexey Khoroshilov | 42 | 0.48% | 1 | 0.59% |
| Yoshihiro Yunomae | 39 | 0.44% | 2 | 1.18% |
| Omar Sandoval | 39 | 0.44% | 1 | 0.59% |
| Andrew Lutomirski | 31 | 0.35% | 1 | 0.59% |
| Tuomas Tynkkynen | 31 | 0.35% | 1 | 0.59% |
| David Howells | 31 | 0.35% | 1 | 0.59% |
| Jiri Slaby | 27 | 0.31% | 1 | 0.59% |
| Laurent Vivier | 22 | 0.25% | 1 | 0.59% |
| Al Viro | 16 | 0.18% | 3 | 1.78% |
| Matt Redfearn | 16 | 0.18% | 1 | 0.59% |
| Pankaj Gupta | 15 | 0.17% | 1 | 0.59% |
| François Diakhaté | 14 | 0.16% | 1 | 0.59% |
| Alexander Lobakin | 14 | 0.16% | 1 | 0.59% |
| Heinz Graalfs | 12 | 0.14% | 1 | 0.59% |
| Kees Cook | 10 | 0.11% | 1 | 0.59% |
| Cornelia Huck | 7 | 0.08% | 1 | 0.59% |
| Dan Carpenter | 7 | 0.08% | 2 | 1.18% |
| Sasha Levin | 6 | 0.07% | 1 | 0.59% |
| Yangtao Li | 5 | 0.06% | 1 | 0.59% |
| Matthew Wilcox | 5 | 0.06% | 1 | 0.59% |
| Linus Torvalds | 5 | 0.06% | 1 | 0.59% |
| Julia Lawall | 4 | 0.05% | 1 | 0.59% |
| Hans de Goede | 4 | 0.05% | 1 | 0.59% |
| Christoph Hellwig | 4 | 0.05% | 3 | 1.78% |
| Paul Gortmaker | 3 | 0.03% | 1 | 0.59% |
| Wei Yongjun | 3 | 0.03% | 1 | 0.59% |
| Tejun Heo | 3 | 0.03% | 1 | 0.59% |
| Aaron Lu | 2 | 0.02% | 1 | 0.59% |
| Joe Perches | 2 | 0.02% | 2 | 1.18% |
| Thomas Gleixner | 2 | 0.02% | 1 | 0.59% |
| G. Campana | 1 | 0.01% | 1 | 0.59% |
| Arvind Yadav | 1 | 0.01% | 1 | 0.59% |
| Gustavo A. R. Silva | 1 | 0.01% | 1 | 0.59% |
| Juergen Gross | 1 | 0.01% | 1 | 0.59% |
| Total | 8828 | 169 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation * Copyright (C) 2009, 2010, 2011 Red Hat, Inc. * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com> */ #include <linux/cdev.h> #include <linux/debugfs.h> #include <linux/completion.h> #include <linux/device.h> #include <linux/err.h> #include <linux/freezer.h> #include <linux/fs.h> #include <linux/splice.h> #include <linux/pagemap.h> #include <linux/init.h> #include <linux/list.h> #include <linux/poll.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/virtio.h> #include <linux/virtio_console.h> #include <linux/wait.h> #include <linux/workqueue.h> #include <linux/module.h> #include <linux/dma-mapping.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. * * Mainly, it has a linked list for all the consoles in one place so * that callbacks from hvc for get_chars(), put_chars() work properly * across multiple devices and multiple ports per device. */ struct ports_driver_data { /* Used for registering chardevs */ struct class *class; /* Used for exporting per-port information to debugfs */ struct dentry *debugfs_dir; /* List of all the devices we're handling */ struct list_head portdevs; /* * This is used to keep track of the number of hvc consoles * spawned by this driver. This number is given as the first * argument to hvc_alloc(). To correctly map an initial * console spawned via hvc_instantiate to the console being * hooked up via hvc_alloc, we need to pass the same vtermno. * * We also just assume the first console being initialised was * the first one that got used as the initial console. */ unsigned int next_vtermno; /* All the console devices handled by this driver */ struct list_head consoles; }; static struct ports_driver_data pdrvdata = { .next_vtermno = 1}; static DEFINE_SPINLOCK(pdrvdata_lock); static DECLARE_COMPLETION(early_console_added); /* This struct holds information that's relevant only for console ports */ struct console { /* We'll place all consoles in a list in the pdrvdata struct */ struct list_head list; /* The hvc device associated with this console port */ struct hvc_struct *hvc; /* The size of the console */ struct winsize ws; /* * This number identifies the number that we used to register * with hvc in hvc_instantiate() and hvc_alloc(); this is the * number passed on by the hvc callbacks to us to * differentiate between the other console ports handled by * this driver */ u32 vtermno; }; struct port_buffer { char *buf; /* size of the buffer in *buf above */ size_t size; /* used length of the buffer */ size_t len; /* 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; /* sg is used if spages > 0. sg must be the last in is struct */ struct scatterlist sg[]; }; /* * This is a per-device struct that stores data common to all the * ports for that device (vdev->priv). */ struct ports_device { /* Next portdev in the list, head is in the pdrvdata struct */ struct list_head list; /* * Workqueue handlers where we process deferred work after * notification */ struct work_struct control_work; struct work_struct config_work; struct list_head ports; /* To protect the list of ports */ spinlock_t ports_lock; /* To protect the vq operations for the control channel */ spinlock_t c_ivq_lock; spinlock_t c_ovq_lock; /* max. number of ports this device can hold */ u32 max_nr_ports; /* The virtio device we're associated with */ struct virtio_device *vdev; /* * A couple of virtqueues for the control channel: one for * guest->host transfers, one for host->guest transfers */ struct virtqueue *c_ivq, *c_ovq; /* * A control packet buffer for guest->host requests, protected * by c_ovq_lock. */ struct virtio_console_control cpkt; /* Array of per-port IO virtqueues */ struct virtqueue **in_vqs, **out_vqs; /* Major number for this device. Ports will be created as minors. */ int chr_major; }; struct port_stats { unsigned long bytes_sent, bytes_received, bytes_discarded; }; /* This struct holds the per-port data */ struct port { /* Next port in the list, head is in the ports_device */ struct list_head list; /* Pointer to the parent virtio_console device */ struct ports_device *portdev; /* The current buffer from which data has to be fed to readers */ struct port_buffer *inbuf; /* * To protect the operations on the in_vq associated with this * port. Has to be a spinlock because it can be called from * interrupt context (get_char()). */ spinlock_t inbuf_lock; /* Protect the operations on the out_vq. */ spinlock_t outvq_lock; /* The IO vqs for this port */ struct virtqueue *in_vq, *out_vq; /* File in the debugfs directory that exposes this port's information */ struct dentry *debugfs_file; /* * Keep count of the bytes sent, received and discarded for * this port for accounting and debugging purposes. These * counts are not reset across port open / close events. */ struct port_stats stats; /* * The entries in this struct will be valid if this port is * hooked up to an hvc console */ struct console cons; /* Each port associates with a separate char device */ struct cdev *cdev; struct device *dev; /* Reference-counting to handle port hot-unplugs and file operations */ struct kref kref; /* A waitqueue for poll() or blocking read operations */ wait_queue_head_t waitqueue; /* The 'name' of the port that we expose via sysfs properties */ char *name; /* We can notify apps of host connect / disconnect events via SIGIO */ struct fasync_struct *async_queue; /* The 'id' to identify the port with the Host */ u32 id; bool outvq_full; /* Is the host device open */ bool host_connected; /* We should allow only one process to open a port */ bool guest_connected; }; /* This is the very early arch-specified put chars function. */ static int (*early_put_chars)(u32, const char *, int); static struct port *find_port_by_vtermno(u32 vtermno) { struct port *port; struct console *cons; unsigned long flags; spin_lock_irqsave(&pdrvdata_lock, flags); list_for_each_entry(cons, &pdrvdata.consoles, list) { if (cons->vtermno == vtermno) { port = container_of(cons, struct port, cons); goto out; } } port = NULL; out: spin_unlock_irqrestore(&pdrvdata_lock, flags); return port; } static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev, dev_t dev) { struct port *port; unsigned long flags; spin_lock_irqsave(&portdev->ports_lock, flags); list_for_each_entry(port, &portdev->ports, list) { if (port->cdev->dev == dev) { kref_get(&port->kref); goto out; } } port = NULL; out: spin_unlock_irqrestore(&portdev->ports_lock, flags); return port; } static struct port *find_port_by_devt(dev_t dev) { struct ports_device *portdev; struct port *port; unsigned long flags; spin_lock_irqsave(&pdrvdata_lock, flags); list_for_each_entry(portdev, &pdrvdata.portdevs, list) { port = find_port_by_devt_in_portdev(portdev, dev); if (port) goto out; } port = NULL; out: spin_unlock_irqrestore(&pdrvdata_lock, flags); return port; } static struct port *find_port_by_id(struct ports_device *portdev, u32 id) { struct port *port; unsigned long flags; spin_lock_irqsave(&portdev->ports_lock, flags); list_for_each_entry(port, &portdev->ports, list) if (port->id == id) goto out; port = NULL; out: spin_unlock_irqrestore(&portdev->ports_lock, flags); return port; } static struct port *find_port_by_vq(struct ports_device *portdev, struct virtqueue *vq) { struct port *port; unsigned long flags; spin_lock_irqsave(&portdev->ports_lock, flags); list_for_each_entry(port, &portdev->ports, list) if (port->in_vq == vq || port->out_vq == vq) goto out; port = NULL; out: spin_unlock_irqrestore(&portdev->ports_lock, flags); return port; } static bool is_console_port(struct port *port) { if (port->cons.hvc) return true; 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) { /* * This condition can be true when put_chars is called from * early_init */ if (!portdev->vdev) return false; return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT); } 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; for (i = 0; i < buf->sgpages; i++) { struct page *page = sg_page(&buf->sg[i]); if (!page) break; 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 virtio_device *vdev, 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. */ buf = kmalloc(struct_size(buf, sg, pages), GFP_KERNEL); if (!buf) goto fail; buf->sgpages = pages; if (pages > 0) { buf->dev = NULL; buf->buf = NULL; return buf; } if (is_rproc_serial(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. */ if (!vdev->dev.parent || !vdev->dev.parent->parent) goto free_buf; buf->dev = 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; buf->offset = 0; buf->size = buf_size; return buf; free_buf: kfree(buf); fail: return NULL; } /* Callers should take appropriate locks */ static struct port_buffer *get_inbuf(struct port *port) { struct port_buffer *buf; unsigned int len; if (port->inbuf) return port->inbuf; buf = virtqueue_get_buf(port->in_vq, &len); if (buf) { buf->len = len; buf->offset = 0; port->stats.bytes_received += len; } return buf; } /* * Create a scatter-gather list representing our input buffer and put * it in the queue. * * Callers should take appropriate locks. */ static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf) { struct scatterlist sg[1]; int ret; sg_init_one(sg, buf->buf, buf->size); ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC); virtqueue_kick(vq); if (!ret) ret = vq->num_free; return ret; } /* Discard any unread data this port has. Callers lockers. */ static void discard_port_data(struct port *port) { struct port_buffer *buf; unsigned int err; if (!port->portdev) { /* Device has been unplugged. vqs are already gone. */ return; } buf = get_inbuf(port); err = 0; while (buf) { port->stats.bytes_discarded += buf->len - buf->offset; if (add_inbuf(port->in_vq, buf) < 0) { err++; free_buf(buf, false); } port->inbuf = NULL; buf = get_inbuf(port); } if (err) dev_warn(port->dev, "Errors adding %d buffers back to vq\n", err); } static bool port_has_data(struct port *port) { unsigned long flags; bool ret; ret = false; spin_lock_irqsave(&port->inbuf_lock, flags); port->inbuf = get_inbuf(port); if (port->inbuf) ret = true; spin_unlock_irqrestore(&port->inbuf_lock, flags); return ret; } static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id, unsigned int event, unsigned int value) { struct scatterlist sg[1]; struct virtqueue *vq; unsigned int len; if (!use_multiport(portdev)) return 0; vq = portdev->c_ovq; spin_lock(&portdev->c_ovq_lock); portdev->cpkt.id = cpu_to_virtio32(portdev->vdev, port_id); portdev->cpkt.event = cpu_to_virtio16(portdev->vdev, event); portdev->cpkt.value = cpu_to_virtio16(portdev->vdev, value); sg_init_one(sg, &portdev->cpkt, sizeof(struct virtio_console_control)); if (virtqueue_add_outbuf(vq, sg, 1, &portdev->cpkt, GFP_ATOMIC) == 0) { virtqueue_kick(vq); while (!virtqueue_get_buf(vq, &len) && !virtqueue_is_broken(vq)) cpu_relax(); } spin_unlock(&portdev->c_ovq_lock); return 0; } static ssize_t send_control_msg(struct port *port, unsigned int event, unsigned int value) { /* Did the port get unplugged before userspace closed it? */ if (port->portdev) return __send_control_msg(port->portdev, port->id, event, value); return 0; } /* Callers must take the port->outvq_lock */ static void reclaim_consumed_buffers(struct port *port) { struct port_buffer *buf; unsigned int len; if (!port->portdev) { /* Device has been unplugged. vqs are already gone. */ return; } while ((buf = virtqueue_get_buf(port->out_vq, &len))) { free_buf(buf, false); port->outvq_full = false; } } static ssize_t __send_to_port(struct port *port, struct scatterlist *sg, int nents, size_t in_count, void *data, bool nonblock) { struct virtqueue *out_vq; int err; unsigned long flags; unsigned int len; out_vq = port->out_vq; spin_lock_irqsave(&port->outvq_lock, flags); reclaim_consumed_buffers(port); err = virtqueue_add_outbuf(out_vq, sg, nents, data, GFP_ATOMIC); /* Tell Host to go! */ virtqueue_kick(out_vq); if (err) { in_count = 0; goto done; } if (out_vq->num_free == 0) port->outvq_full = true; if (nonblock) goto done; /* * Wait till the host acknowledges it pushed out the data we * sent. This is done for data from the hvc_console; the tty * operations are performed with spinlocks held so we can't * sleep here. An alternative would be to copy the data to a * buffer and relax the spinning requirement. The downside is * we need to kmalloc a GFP_ATOMIC buffer each time the * console driver writes something out. */ while (!virtqueue_get_buf(out_vq, &len) && !virtqueue_is_broken(out_vq)) cpu_relax(); done: spin_unlock_irqrestore(&port->outvq_lock, flags); port->stats.bytes_sent += in_count; /* * We're expected to return the amount of data we wrote -- all * of it */ return in_count; } /* * Give out the data that's requested from the buffer that we have * queued up. */ static ssize_t fill_readbuf(struct port *port, char __user *out_buf, size_t out_count, bool to_user) { struct port_buffer *buf; unsigned long flags; if (!out_count || !port_has_data(port)) return 0; buf = port->inbuf; out_count = min(out_count, buf->len - buf->offset); if (to_user) { ssize_t ret; ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count); if (ret) return -EFAULT; } else { memcpy((__force char *)out_buf, buf->buf + buf->offset, out_count); } buf->offset += out_count; if (buf->offset == buf->len) { /* * We're done using all the data in this buffer. * Re-queue so that the Host can send us more data. */ spin_lock_irqsave(&port->inbuf_lock, flags); port->inbuf = NULL; if (add_inbuf(port->in_vq, buf) < 0) dev_warn(port->dev, "failed add_buf\n"); spin_unlock_irqrestore(&port->inbuf_lock, flags); } /* Return the number of bytes actually copied */ return out_count; } /* The condition that must be true for polling to end */ static bool will_read_block(struct port *port) { if (!port->guest_connected) { /* Port got hot-unplugged. Let's exit. */ return false; } return !port_has_data(port) && port->host_connected; } static bool will_write_block(struct port *port) { bool ret; if (!port->guest_connected) { /* Port got hot-unplugged. Let's exit. */ return false; } if (!port->host_connected) return true; spin_lock_irq(&port->outvq_lock); /* * Check if the Host has consumed any buffers since we last * sent data (this is only applicable for nonblocking ports). */ reclaim_consumed_buffers(port); ret = port->outvq_full; spin_unlock_irq(&port->outvq_lock); return ret; } static ssize_t port_fops_read(struct file *filp, char __user *ubuf, size_t count, loff_t *offp) { struct port *port; ssize_t ret; port = filp->private_data; /* Port is hot-unplugged. */ if (!port->guest_connected) return -ENODEV; if (!port_has_data(port)) { /* * If nothing's connected on the host just return 0 in * case of list_empty; this tells the userspace app * that there's no connection */ if (!port->host_connected) return 0; if (filp->f_flags & O_NONBLOCK) return -EAGAIN; ret = wait_event_freezable(port->waitqueue, !will_read_block(port)); if (ret < 0) return ret; } /* Port got hot-unplugged while we were waiting above. */ if (!port->guest_connected) return -ENODEV; /* * We could've received a disconnection message while we were * waiting for more data. * * This check is not clubbed in the if() statement above as we * might receive some data as well as the host could get * disconnected after we got woken up from our wait. So we * really want to give off whatever data we have and only then * check for host_connected. */ if (!port_has_data(port) && !port->host_connected) return 0; return fill_readbuf(port, ubuf, count, true); } static int wait_port_writable(struct port *port, bool nonblock) { int ret; if (will_write_block(port)) { if (nonblock) return -EAGAIN; ret = wait_event_freezable(port->waitqueue, !will_write_block(port)); if (ret < 0) return ret; } /* Port got hot-unplugged. */ if (!port->guest_connected) return -ENODEV; return 0; } static ssize_t port_fops_write(struct file *filp, const char __user *ubuf, size_t count, loff_t *offp) { struct port *port; struct port_buffer *buf; ssize_t ret; bool nonblock; struct scatterlist sg[1]; /* Userspace could be out to fool us */ if (!count) return 0; port = filp->private_data; nonblock = filp->f_flags & O_NONBLOCK; ret = wait_port_writable(port, nonblock); if (ret < 0) return ret; count = min((size_t)(32 * 1024), count); buf = alloc_buf(port->portdev->vdev, count, 0); if (!buf) return -ENOMEM; ret = copy_from_user(buf->buf, ubuf, count); if (ret) { ret = -EFAULT; goto free_buf; } /* * We now ask send_buf() to not spin for generic ports -- we * can re-use the same code path that non-blocking file * descriptors take for blocking file descriptors since the * wait is already done and we're certain the write will go * through to the host. */ nonblock = true; sg_init_one(sg, buf->buf, count); ret = __send_to_port(port, sg, 1, count, buf, nonblock); if (nonblock && ret > 0) goto out; free_buf: free_buf(buf, true); out: return ret; } struct sg_list { unsigned int n; unsigned int size; size_t len; struct scatterlist *sg; }; static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf, struct splice_desc *sd) { struct sg_list *sgl = sd->u.data; unsigned int offset, len; if (sgl->n == sgl->size) return 0; /* Try lock this page */ if (pipe_buf_try_steal(pipe, buf)) { /* Get reference and unlock page for moving */ get_page(buf->page); unlock_page(buf->page); len = min(buf->len, sd->len); sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset); } else { /* Failback to copying a page */ struct page *page = alloc_page(GFP_KERNEL); char *src; if (!page) return -ENOMEM; offset = sd->pos & ~PAGE_MASK; len = sd->len; if (len + offset > PAGE_SIZE) len = PAGE_SIZE - offset; src = kmap_atomic(buf->page); memcpy(page_address(page) + offset, src + buf->offset, len); kunmap_atomic(src); sg_set_page(&(sgl->sg[sgl->n]), page, len, offset); } sgl->n++; sgl->len += len; return len; } /* Faster zero-copy write by splicing */ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe, struct file *filp, loff_t *ppos, size_t len, unsigned int flags) { struct port *port = filp->private_data; struct sg_list sgl; ssize_t ret; struct port_buffer *buf; struct splice_desc sd = { .total_len = len, .flags = flags, .pos = *ppos, .u.data = &sgl, }; unsigned int occupancy; /* * 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; pipe_lock(pipe); ret = 0; if (pipe_empty(pipe->head, pipe->tail)) goto error_out; ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK); if (ret < 0) goto error_out; occupancy = pipe_occupancy(pipe->head, pipe->tail); buf = alloc_buf(port->portdev->vdev, 0, occupancy); if (!buf) { ret = -ENOMEM; goto error_out; } sgl.n = 0; sgl.len = 0; sgl.size = occupancy; sgl.sg = buf->sg; sg_init_table(sgl.sg, sgl.size); ret = __splice_from_pipe(pipe, &sd, pipe_to_sg); pipe_unlock(pipe); if (likely(ret > 0)) ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true); if (unlikely(ret <= 0)) free_buf(buf, true); return ret; error_out: pipe_unlock(pipe); return ret; } static __poll_t port_fops_poll(struct file *filp, poll_table *wait) { struct port *port; __poll_t ret; port = filp->private_data; poll_wait(filp, &port->waitqueue, wait); if (!port->guest_connected) { /* Port got unplugged */ return EPOLLHUP; } ret = 0; if (!will_read_block(port)) ret |= EPOLLIN | EPOLLRDNORM; if (!will_write_block(port)) ret |= EPOLLOUT; if (!port->host_connected) ret |= EPOLLHUP; return ret; } static void remove_port(struct kref *kref); static int port_fops_release(struct inode *inode, struct file *filp) { struct port *port; port = filp->private_data; /* Notify host of port being closed */ send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0); spin_lock_irq(&port->inbuf_lock); port->guest_connected = false; discard_port_data(port); spin_unlock_irq(&port->inbuf_lock); spin_lock_irq(&port->outvq_lock); 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 * exist for the port. Plus, taking ports_lock here would * create a dependency on other locks taken by functions * inside remove_port if we're the last holder of the port, * creating many problems. */ kref_put(&port->kref, remove_port); return 0; } static int port_fops_open(struct inode *inode, struct file *filp) { struct cdev *cdev = inode->i_cdev; struct port *port; int ret; /* We get the port with a kref here */ port = find_port_by_devt(cdev->dev); if (!port) { /* Port was unplugged before we could proceed */ return -ENXIO; } filp->private_data = port; /* * Don't allow opening of console port devices -- that's done * via /dev/hvc */ if (is_console_port(port)) { ret = -ENXIO; goto out; } /* Allow only one process to open a particular port at a time */ spin_lock_irq(&port->inbuf_lock); if (port->guest_connected) { spin_unlock_irq(&port->inbuf_lock); ret = -EBUSY; goto out; } port->guest_connected = true; spin_unlock_irq(&port->inbuf_lock); spin_lock_irq(&port->outvq_lock); /* * There might be a chance that we missed reclaiming a few * buffers in the window of the port getting previously closed * and opening now. */ reclaim_consumed_buffers(port); spin_unlock_irq(&port->outvq_lock); nonseekable_open(inode, filp); /* Notify host of port being opened */ send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1); return 0; out: kref_put(&port->kref, remove_port); return ret; } static int port_fops_fasync(int fd, struct file *filp, int mode) { struct port *port; port = filp->private_data; return fasync_helper(fd, filp, mode, &port->async_queue); } /* * The file operations that we support: programs in the guest can open * a console device, read from it, write to it, poll for data and * close it. The devices are at * /dev/vport<device number>p<port number> */ static const struct file_operations port_fops = { .owner = THIS_MODULE, .open = port_fops_open, .read = port_fops_read, .write = port_fops_write, .splice_write = port_fops_splice_write, .poll = port_fops_poll, .release = port_fops_release, .fasync = port_fops_fasync, .llseek = no_llseek, }; /* * The put_chars() callback is pretty straightforward. * * We turn the characters into a scatter-gather list, add it to the * output queue and then kick the Host. Then we sit here waiting for * it to finish: inefficient in theory, but in practice * implementations will do it immediately. */ static int put_chars(u32 vtermno, const char *buf, int count) { struct port *port; struct scatterlist sg[1]; void *data; int ret; if (unlikely(early_put_chars)) return early_put_chars(vtermno, buf, count); port = find_port_by_vtermno(vtermno); if (!port) return -EPIPE; data = kmemdup(buf, count, GFP_ATOMIC); if (!data) return -ENOMEM; sg_init_one(sg, data, count); ret = __send_to_port(port, sg, 1, count, data, false); kfree(data); return ret; } /* * get_chars() is the callback from the hvc_console infrastructure * when an interrupt is received. * * We call out to fill_readbuf that gets us the required data from the * buffers that are queued up. */ static int get_chars(u32 vtermno, char *buf, int count) { struct port *port; /* If we've not set up the port yet, we have no input to give. */ if (unlikely(early_put_chars)) return 0; port = find_port_by_vtermno(vtermno); if (!port) return -EPIPE; /* If we don't have an input queue yet, we can't get input. */ BUG_ON(!port->in_vq); return fill_readbuf(port, (__force char __user *)buf, count, false); } static void resize_console(struct port *port) { struct virtio_device *vdev; /* The port could have been hot-unplugged */ if (!port || !is_console_port(port)) return; vdev = port->portdev->vdev; /* 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); } /* We set the configuration at this point, since we now have a tty */ static int notifier_add_vio(struct hvc_struct *hp, int data) { struct port *port; port = find_port_by_vtermno(hp->vtermno); if (!port) return -EINVAL; hp->irq_requested = 1; resize_console(port); return 0; } static void notifier_del_vio(struct hvc_struct *hp, int data) { hp->irq_requested = 0; } /* The operations for console ports. */ static const struct hv_ops hv_ops = { .get_chars = get_chars, .put_chars = put_chars, .notifier_add = notifier_add_vio, .notifier_del = notifier_del_vio, .notifier_hangup = notifier_del_vio, }; /* * Console drivers are initialized very early so boot messages can go * out, so we do things slightly differently from the generic virtio * initialization of the net and block drivers. * * At this stage, the console is output-only. It's too early to set * up a virtqueue, so we let the drivers do some boutique early-output * thing. */ int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)) { early_put_chars = put_chars; return hvc_instantiate(0, 0, &hv_ops); } static int init_port_console(struct port *port) { int ret; /* * The Host's telling us this port is a console port. Hook it * up with an hvc console. * * To set up and manage our virtual console, we call * hvc_alloc(). * * The first argument of hvc_alloc() is the virtual console * number. The second argument is the parameter for the * notification mechanism (like irq number). We currently * leave this as zero, virtqueues have implicit notifications. * * The third argument is a "struct hv_ops" containing the * put_chars() get_chars(), notifier_add() and notifier_del() * pointers. The final argument is the output buffer size: we * can do any size, so we put PAGE_SIZE here. */ port->cons.vtermno = pdrvdata.next_vtermno; port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE); if (IS_ERR(port->cons.hvc)) { ret = PTR_ERR(port->cons.hvc); dev_err(port->dev, "error %d allocating hvc for port\n", ret); port->cons.hvc = NULL; return ret; } spin_lock_irq(&pdrvdata_lock); pdrvdata.next_vtermno++; list_add_tail(&port->cons.list, &pdrvdata.consoles); spin_unlock_irq(&pdrvdata_lock); port->guest_connected = true; /* * Start using the new console output if this is the first * console to come up. */ if (early_put_chars) early_put_chars = NULL; /* Notify host of port being opened */ send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1); return 0; } static ssize_t show_port_name(struct device *dev, struct device_attribute *attr, char *buffer) { struct port *port; port = dev_get_drvdata(dev); return sprintf(buffer, "%s\n", port->name); } static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL); static struct attribute *port_sysfs_entries[] = { &dev_attr_name.attr, NULL }; static const struct attribute_group port_attribute_group = { .name = NULL, /* put in device directory */ .attrs = port_sysfs_entries, }; static int port_debugfs_show(struct seq_file *s, void *data) { struct port *port = s->private; seq_printf(s, "name: %s\n", port->name ? port->name : ""); seq_printf(s, "guest_connected: %d\n", port->guest_connected); seq_printf(s, "host_connected: %d\n", port->host_connected); seq_printf(s, "outvq_full: %d\n", port->outvq_full); seq_printf(s, "bytes_sent: %lu\n", port->stats.bytes_sent); seq_printf(s, "bytes_received: %lu\n", port->stats.bytes_received); seq_printf(s, "bytes_discarded: %lu\n", port->stats.bytes_discarded); seq_printf(s, "is_console: %s\n", is_console_port(port) ? "yes" : "no"); seq_printf(s, "console_vtermno: %u\n", port->cons.vtermno); return 0; } DEFINE_SHOW_ATTRIBUTE(port_debugfs); static void set_console_size(struct port *port, u16 rows, u16 cols) { if (!port || !is_console_port(port)) return; port->cons.ws.ws_row = rows; port->cons.ws.ws_col = cols; } static int fill_queue(struct virtqueue *vq, spinlock_t *lock) { struct port_buffer *buf; int nr_added_bufs; int ret; nr_added_bufs = 0; do { buf = alloc_buf(vq->vdev, PAGE_SIZE, 0); if (!buf) return -ENOMEM; spin_lock_irq(lock); ret = add_inbuf(vq, buf); if (ret < 0) { spin_unlock_irq(lock); free_buf(buf, true); return ret; } nr_added_bufs++; spin_unlock_irq(lock); } while (ret > 0); return nr_added_bufs; } static void send_sigio_to_port(struct port *port) { if (port->async_queue && port->guest_connected) kill_fasync(&port->async_queue, SIGIO, POLL_OUT); } static int add_port(struct ports_device *portdev, u32 id) { char debugfs_name[16]; struct port *port; dev_t devt; int err; port = kmalloc(sizeof(*port), GFP_KERNEL); if (!port) { err = -ENOMEM; goto fail; } kref_init(&port->kref); port->portdev = portdev; port->id = id; port->name = NULL; port->inbuf = NULL; port->cons.hvc = NULL; port->async_queue = NULL; port->cons.ws.ws_row = port->cons.ws.ws_col = 0; port->cons.vtermno = 0; port->host_connected = port->guest_connected = false; port->stats = (struct port_stats) { 0 }; port->outvq_full = false; port->in_vq = portdev->in_vqs[port->id]; port->out_vq = portdev->out_vqs[port->id]; port->cdev = cdev_alloc(); if (!port->cdev) { dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n"); err = -ENOMEM; goto free_port; } port->cdev->ops = &port_fops; devt = MKDEV(portdev->chr_major, id); err = cdev_add(port->cdev, devt, 1); if (err < 0) { dev_err(&port->portdev->vdev->dev, "Error %d adding cdev for port %u\n", err, id); goto free_cdev; } port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev, devt, port, "vport%up%u", port->portdev->vdev->index, id); if (IS_ERR(port->dev)) { err = PTR_ERR(port->dev); dev_err(&port->portdev->vdev->dev, "Error %d creating device for port %u\n", err, id); goto free_cdev; } spin_lock_init(&port->inbuf_lock); spin_lock_init(&port->outvq_lock); init_waitqueue_head(&port->waitqueue); /* We can safely ignore ENOSPC because it means * the queue already has buffers. Buffers are removed * only by virtcons_remove(), not by unplug_port() */ err = fill_queue(port->in_vq, &port->inbuf_lock); if (err < 0 && err != -ENOSPC) { dev_err(port->dev, "Error allocating inbufs\n"); 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. */ err = init_port_console(port); if (err) goto free_inbufs; } spin_lock_irq(&portdev->ports_lock); list_add_tail(&port->list, &port->portdev->ports); spin_unlock_irq(&portdev->ports_lock); /* * Tell the Host we're set so that it can send us various * configuration parameters for this port (eg, port name, * caching, whether this is a console port, etc.) */ send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); if (pdrvdata.debugfs_dir) { /* * Finally, create the debugfs file that we can use to * inspect a port's state at any time */ snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u", port->portdev->vdev->index, id); port->debugfs_file = debugfs_create_file(debugfs_name, 0444, pdrvdata.debugfs_dir, port, &port_debugfs_fops); } return 0; free_inbufs: free_device: device_destroy(pdrvdata.class, port->dev->devt); free_cdev: cdev_del(port->cdev); free_port: kfree(port); fail: /* The host might want to notify management sw about port add failure */ __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0); return err; } /* No users remain, remove all port-specific data. */ static void remove_port(struct kref *kref) { struct port *port; port = container_of(kref, struct port, kref); kfree(port); } static void remove_port_data(struct port *port) { spin_lock_irq(&port->inbuf_lock); /* Remove unused data this port might have received. */ discard_port_data(port); spin_unlock_irq(&port->inbuf_lock); spin_lock_irq(&port->outvq_lock); reclaim_consumed_buffers(port); spin_unlock_irq(&port->outvq_lock); } /* * Port got unplugged. Remove port from portdev's list and drop the * kref reference. If no userspace has this port opened, it will * result in immediate removal the port. */ static void unplug_port(struct port *port) { spin_lock_irq(&port->portdev->ports_lock); list_del(&port->list); spin_unlock_irq(&port->portdev->ports_lock); spin_lock_irq(&port->inbuf_lock); if (port->guest_connected) { /* Let the app know the port is going down. */ send_sigio_to_port(port); /* Do this after sigio is actually sent */ port->guest_connected = false; port->host_connected = false; wake_up_interruptible(&port->waitqueue); } spin_unlock_irq(&port->inbuf_lock); if (is_console_port(port)) { spin_lock_irq(&pdrvdata_lock); list_del(&port->cons.list); spin_unlock_irq(&pdrvdata_lock); hvc_remove(port->cons.hvc); } remove_port_data(port); /* * We should just assume the device itself has gone off -- * else a close on an open port later will try to send out a * control message. */ port->portdev = NULL; sysfs_remove_group(&port->dev->kobj, &port_attribute_group); device_destroy(pdrvdata.class, port->dev->devt); cdev_del(port->cdev); debugfs_remove(port->debugfs_file); kfree(port->name); /* * Locks around here are not necessary - a port can't be * opened after we removed the port struct from ports_list * above. */ kref_put(&port->kref, remove_port); } /* Any private messages that the Host and Guest want to share */ static void handle_control_message(struct virtio_device *vdev, struct ports_device *portdev, struct port_buffer *buf) { struct virtio_console_control *cpkt; struct port *port; size_t name_size; int err; cpkt = (struct virtio_console_control *)(buf->buf + buf->offset); port = find_port_by_id(portdev, virtio32_to_cpu(vdev, cpkt->id)); if (!port && cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) { /* No valid header at start of buffer. Drop it. */ dev_dbg(&portdev->vdev->dev, "Invalid index %u in control packet\n", cpkt->id); return; } switch (virtio16_to_cpu(vdev, cpkt->event)) { case VIRTIO_CONSOLE_PORT_ADD: if (port) { dev_dbg(&portdev->vdev->dev, "Port %u already added\n", port->id); send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); break; } if (virtio32_to_cpu(vdev, cpkt->id) >= portdev->max_nr_ports) { dev_warn(&portdev->vdev->dev, "Request for adding port with " "out-of-bound id %u, max. supported id: %u\n", cpkt->id, portdev->max_nr_ports - 1); break; } add_port(portdev, virtio32_to_cpu(vdev, cpkt->id)); break; case VIRTIO_CONSOLE_PORT_REMOVE: unplug_port(port); break; case VIRTIO_CONSOLE_CONSOLE_PORT: if (!cpkt->value) break; if (is_console_port(port)) break; init_port_console(port); complete(&early_console_added); /* * Could remove the port here in case init fails - but * have to notify the host first. */ break; case VIRTIO_CONSOLE_RESIZE: { struct { __u16 rows; __u16 cols; } size; if (!is_console_port(port)) break; memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt), sizeof(size)); set_console_size(port, size.rows, size.cols); port->cons.hvc->irq_requested = 1; resize_console(port); break; } case VIRTIO_CONSOLE_PORT_OPEN: port->host_connected = virtio16_to_cpu(vdev, cpkt->value); wake_up_interruptible(&port->waitqueue); /* * If the host port got closed and the host had any * unconsumed buffers, we'll be able to reclaim them * now. */ spin_lock_irq(&port->outvq_lock); reclaim_consumed_buffers(port); spin_unlock_irq(&port->outvq_lock); /* * If the guest is connected, it'll be interested in * knowing the host connection state changed. */ spin_lock_irq(&port->inbuf_lock); send_sigio_to_port(port); spin_unlock_irq(&port->inbuf_lock); break; case VIRTIO_CONSOLE_PORT_NAME: /* * If we woke up after hibernation, we can get this * again. Skip it in that case. */ if (port->name) break; /* * Skip the size of the header and the cpkt to get the size * of the name that was sent */ name_size = buf->len - buf->offset - sizeof(*cpkt) + 1; port->name = kmalloc(name_size, GFP_KERNEL); if (!port->name) { dev_err(port->dev, "Not enough space to store port name\n"); break; } strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt), name_size - 1); port->name[name_size - 1] = 0; /* * Since we only have one sysfs attribute, 'name', * create it only if we have a name for the port. */ err = sysfs_create_group(&port->dev->kobj, &port_attribute_group); if (err) { dev_err(port->dev, "Error %d creating sysfs device attributes\n", err); } else { /* * Generate a udev event so that appropriate * symlinks can be created based on udev * rules. */ kobject_uevent(&port->dev->kobj, KOBJ_CHANGE); } break; } } static void control_work_handler(struct work_struct *work) { struct ports_device *portdev; struct virtqueue *vq; struct port_buffer *buf; unsigned int len; portdev = container_of(work, struct ports_device, control_work); vq = portdev->c_ivq; spin_lock(&portdev->c_ivq_lock); while ((buf = virtqueue_get_buf(vq, &len))) { spin_unlock(&portdev->c_ivq_lock); buf->len = len; buf->offset = 0; handle_control_message(vq->vdev, portdev, buf); spin_lock(&portdev->c_ivq_lock); if (add_inbuf(portdev->c_ivq, buf) < 0) { dev_warn(&portdev->vdev->dev, "Error adding buffer to queue\n"); free_buf(buf, false); } } spin_unlock(&portdev->c_ivq_lock); } static void flush_bufs(struct virtqueue *vq, bool can_sleep) { struct port_buffer *buf; unsigned int len; while ((buf = virtqueue_get_buf(vq, &len))) free_buf(buf, can_sleep); } static void out_intr(struct virtqueue *vq) { struct port *port; port = find_port_by_vq(vq->vdev->priv, vq); if (!port) { flush_bufs(vq, false); return; } wake_up_interruptible(&port->waitqueue); } static void in_intr(struct virtqueue *vq) { struct port *port; unsigned long flags; port = find_port_by_vq(vq->vdev->priv, vq); if (!port) { flush_bufs(vq, false); return; } spin_lock_irqsave(&port->inbuf_lock, flags); port->inbuf = get_inbuf(port); /* * Normally the port should not accept data when the port is * closed. For generic serial ports, the host won't (shouldn't) * send data till the guest is connected. But this condition * can be reached when a console port is not yet connected (no * tty is spawned) and the other side sends out data over the * vring, or when a remote devices start sending data before * the ports are opened. * * A generic serial port will discard data if not connected, * while console ports and rproc-serial ports accepts data at * any time. rproc-serial is initiated with guest_connected to * false because port_fops_open expects this. Console ports are * hooked up with an HVC console and is initialized with * guest_connected to true. */ if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev)) discard_port_data(port); /* Send a SIGIO indicating new data in case the process asked for it */ send_sigio_to_port(port); spin_unlock_irqrestore(&port->inbuf_lock, flags); wake_up_interruptible(&port->waitqueue); if (is_console_port(port) && hvc_poll(port->cons.hvc)) hvc_kick(); } static void control_intr(struct virtqueue *vq) { struct ports_device *portdev; portdev = vq->vdev->priv; schedule_work(&portdev->control_work); } static void config_intr(struct virtio_device *vdev) { struct ports_device *portdev; portdev = vdev->priv; if (!use_multiport(portdev)) schedule_work(&portdev->config_work); } static void config_work_handler(struct work_struct *work) { struct ports_device *portdev; portdev = container_of(work, struct ports_device, config_work); if (!use_multiport(portdev)) { struct virtio_device *vdev; struct port *port; u16 rows, cols; vdev = portdev->vdev; virtio_cread(vdev, struct virtio_console_config, cols, &cols); virtio_cread(vdev, struct virtio_console_config, rows, &rows); port = find_port_by_id(portdev, 0); set_console_size(port, rows, cols); /* * We'll use this way of resizing only for legacy * support. For newer userspace * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages * to indicate console size changes so that it can be * done per-port. */ resize_console(port); } } static int init_vqs(struct ports_device *portdev) { vq_callback_t **io_callbacks; char **io_names; struct virtqueue **vqs; u32 i, j, nr_ports, nr_queues; int err; nr_ports = portdev->max_nr_ports; nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2; vqs = kmalloc_array(nr_queues, sizeof(struct virtqueue *), GFP_KERNEL); io_callbacks = kmalloc_array(nr_queues, sizeof(vq_callback_t *), GFP_KERNEL); io_names = kmalloc_array(nr_queues, sizeof(char *), GFP_KERNEL); portdev->in_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *), GFP_KERNEL); portdev->out_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *), GFP_KERNEL); if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs || !portdev->out_vqs) { err = -ENOMEM; goto free; } /* * For backward compat (newer host but older guest), the host * spawns a console port first and also inits the vqs for port * 0 before others. */ j = 0; io_callbacks[j] = in_intr; io_callbacks[j + 1] = out_intr; io_names[j] = "input"; io_names[j + 1] = "output"; j += 2; if (use_multiport(portdev)) { io_callbacks[j] = control_intr; io_callbacks[j + 1] = NULL; io_names[j] = "control-i"; io_names[j + 1] = "control-o"; for (i = 1; i < nr_ports; i++) { j += 2; io_callbacks[j] = in_intr; io_callbacks[j + 1] = out_intr; io_names[j] = "input"; io_names[j + 1] = "output"; } } /* Find the queues. */ err = virtio_find_vqs(portdev->vdev, nr_queues, vqs, io_callbacks, (const char **)io_names, NULL); if (err) goto free; j = 0; portdev->in_vqs[0] = vqs[0]; portdev->out_vqs[0] = vqs[1]; j += 2; if (use_multiport(portdev)) { portdev->c_ivq = vqs[j]; portdev->c_ovq = vqs[j + 1]; for (i = 1; i < nr_ports; i++) { j += 2; portdev->in_vqs[i] = vqs[j]; portdev->out_vqs[i] = vqs[j + 1]; } } kfree(io_names); kfree(io_callbacks); kfree(vqs); return 0; free: kfree(portdev->out_vqs); kfree(portdev->in_vqs); kfree(io_names); kfree(io_callbacks); kfree(vqs); return err; } static const struct file_operations portdev_fops = { .owner = THIS_MODULE, }; static void remove_vqs(struct ports_device *portdev) { struct virtqueue *vq; virtio_device_for_each_vq(portdev->vdev, vq) { struct port_buffer *buf; flush_bufs(vq, true); while ((buf = virtqueue_detach_unused_buf(vq))) free_buf(buf, true); } portdev->vdev->config->del_vqs(portdev->vdev); kfree(portdev->in_vqs); kfree(portdev->out_vqs); } static void virtcons_remove(struct virtio_device *vdev) { struct ports_device *portdev; struct port *port, *port2; portdev = vdev->priv; spin_lock_irq(&pdrvdata_lock); list_del(&portdev->list); spin_unlock_irq(&pdrvdata_lock); /* Disable interrupts for vqs */ vdev->config->reset(vdev); /* Finish up work that's lined up */ if (use_multiport(portdev)) cancel_work_sync(&portdev->control_work); else cancel_work_sync(&portdev->config_work); list_for_each_entry_safe(port, port2, &portdev->ports, list) unplug_port(port); unregister_chrdev(portdev->chr_major, "virtio-portsdev"); /* * When yanking out a device, we immediately lose the * (device-side) queues. So there's no point in keeping the * guest side around till we drop our final reference. This * also means that any ports which are in an open state will * have to just stop using the port, as the vqs are going * away. */ remove_vqs(portdev); kfree(portdev); } /* * Once we're further in boot, we get probed like any other virtio * device. * * If the host also supports multiple console ports, we check the * config space to see how many ports the host has spawned. We * initialize each port found. */ static int virtcons_probe(struct virtio_device *vdev) { struct ports_device *portdev; int err; bool multiport; bool early = early_put_chars != NULL; /* We only need a config space if features are offered */ if (!vdev->config->get && (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE) || virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) { dev_err(&vdev->dev, "%s failure: config access disabled\n", __func__); return -EINVAL; } /* Ensure to read early_put_chars now */ barrier(); portdev = kmalloc(sizeof(*portdev), GFP_KERNEL); if (!portdev) { err = -ENOMEM; goto fail; } /* Attach this portdev to this virtio_device, and vice-versa. */ portdev->vdev = vdev; vdev->priv = portdev; portdev->chr_major = register_chrdev(0, "virtio-portsdev", &portdev_fops); if (portdev->chr_major < 0) { dev_err(&vdev->dev, "Error %d registering chrdev for device %u\n", portdev->chr_major, vdev->index); err = portdev->chr_major; goto free; } multiport = false; portdev->max_nr_ports = 1; /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */ if (!is_rproc_serial(vdev) && virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT, struct virtio_console_config, max_nr_ports, &portdev->max_nr_ports) == 0) { multiport = true; } err = init_vqs(portdev); if (err < 0) { dev_err(&vdev->dev, "Error %d initializing vqs\n", err); goto free_chrdev; } spin_lock_init(&portdev->ports_lock); INIT_LIST_HEAD(&portdev->ports); INIT_LIST_HEAD(&portdev->list); virtio_device_ready(portdev->vdev); INIT_WORK(&portdev->config_work, &config_work_handler); INIT_WORK(&portdev->control_work, &control_work_handler); if (multiport) { spin_lock_init(&portdev->c_ivq_lock); spin_lock_init(&portdev->c_ovq_lock); err = fill_queue(portdev->c_ivq, &portdev->c_ivq_lock); if (err < 0) { dev_err(&vdev->dev, "Error allocating buffers for control queue\n"); /* * The host might want to notify mgmt sw about device * add failure. */ __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, VIRTIO_CONSOLE_DEVICE_READY, 0); /* Device was functional: we need full cleanup. */ virtcons_remove(vdev); return err; } } else { /* * For backward compatibility: Create a console port * if we're running on older host. */ add_port(portdev, 0); } spin_lock_irq(&pdrvdata_lock); list_add_tail(&portdev->list, &pdrvdata.portdevs); spin_unlock_irq(&pdrvdata_lock); __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, VIRTIO_CONSOLE_DEVICE_READY, 1); /* * If there was an early virtio console, assume that there are no * other consoles. We need to wait until the hvc_alloc matches the * hvc_instantiate, otherwise tty_open will complain, resulting in * a "Warning: unable to open an initial console" boot failure. * Without multiport this is done in add_port above. With multiport * this might take some host<->guest communication - thus we have to * wait. */ if (multiport && early) wait_for_completion(&early_console_added); return 0; free_chrdev: unregister_chrdev(portdev->chr_major, "virtio-portsdev"); free: kfree(portdev); fail: return err; } static struct virtio_device_id id_table[] = { { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID }, { 0 }, }; MODULE_DEVICE_TABLE(virtio, id_table); static unsigned int features[] = { VIRTIO_CONSOLE_F_SIZE, 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 }, }; MODULE_DEVICE_TABLE(virtio, rproc_serial_id_table); static unsigned int rproc_serial_features[] = { }; #ifdef CONFIG_PM_SLEEP static int virtcons_freeze(struct virtio_device *vdev) { struct ports_device *portdev; struct port *port; portdev = vdev->priv; vdev->config->reset(vdev); if (use_multiport(portdev)) virtqueue_disable_cb(portdev->c_ivq); cancel_work_sync(&portdev->control_work); cancel_work_sync(&portdev->config_work); /* * Once more: if control_work_handler() was running, it would * enable the cb as the last step. */ if (use_multiport(portdev)) virtqueue_disable_cb(portdev->c_ivq); list_for_each_entry(port, &portdev->ports, list) { virtqueue_disable_cb(port->in_vq); virtqueue_disable_cb(port->out_vq); /* * We'll ask the host later if the new invocation has * the port opened or closed. */ port->host_connected = false; remove_port_data(port); } remove_vqs(portdev); return 0; } static int virtcons_restore(struct virtio_device *vdev) { struct ports_device *portdev; struct port *port; int ret; portdev = vdev->priv; ret = init_vqs(portdev); if (ret) return ret; virtio_device_ready(portdev->vdev); if (use_multiport(portdev)) fill_queue(portdev->c_ivq, &portdev->c_ivq_lock); list_for_each_entry(port, &portdev->ports, list) { port->in_vq = portdev->in_vqs[port->id]; port->out_vq = portdev->out_vqs[port->id]; fill_queue(port->in_vq, &port->inbuf_lock); /* Get port open/close status on the host */ send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); /* * If a port was open at the time of suspending, we * have to let the host know that it's still open. */ if (port->guest_connected) send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1); } return 0; } #endif static struct virtio_driver virtio_console = { .feature_table = features, .feature_table_size = ARRAY_SIZE(features), .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, .probe = virtcons_probe, .remove = virtcons_remove, .config_changed = config_intr, #ifdef CONFIG_PM_SLEEP .freeze = virtcons_freeze, .restore = virtcons_restore, #endif }; static struct virtio_driver 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; pdrvdata.class = class_create(THIS_MODULE, "virtio-ports"); if (IS_ERR(pdrvdata.class)) { err = PTR_ERR(pdrvdata.class); pr_err("Error %d creating virtio-ports class\n", err); return err; } pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL); if (!pdrvdata.debugfs_dir) pr_warn("Error creating debugfs dir for virtio-ports\n"); INIT_LIST_HEAD(&pdrvdata.consoles); INIT_LIST_HEAD(&pdrvdata.portdevs); err = register_virtio_driver(&virtio_console); if (err < 0) { 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: debugfs_remove_recursive(pdrvdata.debugfs_dir); class_destroy(pdrvdata.class); return err; } static void __exit fini(void) { reclaim_dma_bufs(); unregister_virtio_driver(&virtio_console); unregister_virtio_driver(&virtio_rproc_serial); class_destroy(pdrvdata.class); debugfs_remove_recursive(pdrvdata.debugfs_dir); } module_init(init); module_exit(fini); MODULE_DESCRIPTION("Virtio console driver"); MODULE_LICENSE("GPL");
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