| /* |
| * 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> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| #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[0]; |
| }; |
| |
| /* |
| * 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_steal(pipe, buf) == 0) { |
| /* 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, |
| }; |
| |
| /* |
| * 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->nrbufs == 0 means there are no data to transfer, |
| * so this returns just 0 for no data. |
| */ |
| pipe_lock(pipe); |
| if (!pipe->nrbufs) { |
| ret = 0; |
| goto error_out; |
| } |
| |
| ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK); |
| if (ret < 0) |
| goto error_out; |
| |
| buf = alloc_buf(port->portdev->vdev, 0, pipe->nrbufs); |
| if (!buf) { |
| ret = -ENOMEM; |
| goto error_out; |
| } |
| |
| sgl.n = 0; |
| sgl.len = 0; |
| sgl.size = pipe->nrbufs; |
| 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 unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock) |
| { |
| struct port_buffer *buf; |
| unsigned int nr_added_bufs; |
| int ret; |
| |
| nr_added_bufs = 0; |
| do { |
| buf = alloc_buf(vq->vdev, PAGE_SIZE, 0); |
| if (!buf) |
| break; |
| |
| spin_lock_irq(lock); |
| ret = add_inbuf(vq, buf); |
| if (ret < 0) { |
| spin_unlock_irq(lock); |
| free_buf(buf, true); |
| break; |
| } |
| 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; |
| unsigned int nr_added_bufs; |
| 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); |
| |
| /* Fill the in_vq with buffers so the host can send us data. */ |
| nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); |
| if (!nr_added_bufs) { |
| dev_err(port->dev, "Error allocating inbufs\n"); |
| err = -ENOMEM; |
| 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) { |
| unsigned int nr_added_bufs; |
| |
| spin_lock_init(&portdev->c_ivq_lock); |
| spin_lock_init(&portdev->c_ovq_lock); |
| |
| nr_added_bufs = fill_queue(portdev->c_ivq, |
| &portdev->c_ivq_lock); |
| if (!nr_added_bufs) { |
| 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 -ENOMEM; |
| } |
| } 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 }, |
| }; |
| |
| 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 }, |
| }; |
| |
| 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_DEVICE_TABLE(virtio, id_table); |
| MODULE_DESCRIPTION("Virtio console driver"); |
| MODULE_LICENSE("GPL"); |