diff options
| -rw-r--r-- | Documentation/lguest/lguest.c | 1 | ||||
| -rw-r--r-- | MAINTAINERS | 6 | ||||
| -rw-r--r-- | drivers/block/virtio_blk.c | 61 | ||||
| -rw-r--r-- | drivers/char/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/char/hvc_beat.c | 2 | ||||
| -rw-r--r-- | drivers/char/hvc_console.c | 7 | ||||
| -rw-r--r-- | drivers/char/hvc_console.h | 7 | ||||
| -rw-r--r-- | drivers/char/hvc_iseries.c | 2 | ||||
| -rw-r--r-- | drivers/char/hvc_iucv.c | 2 | ||||
| -rw-r--r-- | drivers/char/hvc_rtas.c | 2 | ||||
| -rw-r--r-- | drivers/char/hvc_udbg.c | 2 | ||||
| -rw-r--r-- | drivers/char/hvc_vio.c | 2 | ||||
| -rw-r--r-- | drivers/char/hvc_xen.c | 2 | ||||
| -rw-r--r-- | drivers/char/virtio_console.c | 1578 | ||||
| -rw-r--r-- | drivers/virtio/virtio_balloon.c | 109 | ||||
| -rw-r--r-- | drivers/virtio/virtio_pci.c | 2 | ||||
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 59 | ||||
| -rw-r--r-- | include/linux/virtio.h | 4 | ||||
| -rw-r--r-- | include/linux/virtio_balloon.h | 15 | ||||
| -rw-r--r-- | include/linux/virtio_blk.h | 13 | ||||
| -rw-r--r-- | include/linux/virtio_console.h | 30 |
21 files changed, 1721 insertions, 193 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 42208511b5c..3119f5db75b 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -34,7 +34,6 @@ #include <sys/uio.h> #include <termios.h> #include <getopt.h> -#include <zlib.h> #include <assert.h> #include <sched.h> #include <limits.h> diff --git a/MAINTAINERS b/MAINTAINERS index 2533fc45a44..317ed38826d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2393,6 +2393,12 @@ L: linuxppc-dev@ozlabs.org S: Odd Fixes F: drivers/char/hvc_* +VIRTIO CONSOLE DRIVER +M: Amit Shah <amit.shah@redhat.com> +L: virtualization@lists.linux-foundation.org +S: Maintained +F: drivers/char/virtio_console.c + GSPCA FINEPIX SUBDRIVER M: Frank Zago <frank@zago.net> L: linux-media@vger.kernel.org diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 51042f0ba7e..7eff828b211 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -243,10 +243,12 @@ static int index_to_minor(int index) static int __devinit virtblk_probe(struct virtio_device *vdev) { struct virtio_blk *vblk; + struct request_queue *q; int err; u64 cap; - u32 v; - u32 blk_size, sg_elems; + u32 v, blk_size, sg_elems, opt_io_size; + u16 min_io_size; + u8 physical_block_exp, alignment_offset; if (index_to_minor(index) >= 1 << MINORBITS) return -ENOSPC; @@ -293,13 +295,13 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) goto out_mempool; } - vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock); - if (!vblk->disk->queue) { + q = vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock); + if (!q) { err = -ENOMEM; goto out_put_disk; } - vblk->disk->queue->queuedata = vblk; + q->queuedata = vblk; if (index < 26) { sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26); @@ -323,10 +325,10 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) /* If barriers are supported, tell block layer that queue is ordered */ if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) - blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_DRAIN_FLUSH, + blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH, virtblk_prepare_flush); else if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER)) - blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL); + blk_queue_ordered(q, QUEUE_ORDERED_TAG, NULL); /* If disk is read-only in the host, the guest should obey */ if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) @@ -345,14 +347,14 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) set_capacity(vblk->disk, cap); /* We can handle whatever the host told us to handle. */ - blk_queue_max_phys_segments(vblk->disk->queue, vblk->sg_elems-2); - blk_queue_max_hw_segments(vblk->disk->queue, vblk->sg_elems-2); + blk_queue_max_phys_segments(q, vblk->sg_elems-2); + blk_queue_max_hw_segments(q, vblk->sg_elems-2); /* No need to bounce any requests */ - blk_queue_bounce_limit(vblk->disk->queue, BLK_BOUNCE_ANY); + blk_queue_bounce_limit(q, BLK_BOUNCE_ANY); /* No real sector limit. */ - blk_queue_max_sectors(vblk->disk->queue, -1U); + blk_queue_max_sectors(q, -1U); /* Host can optionally specify maximum segment size and number of * segments. */ @@ -360,16 +362,45 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) offsetof(struct virtio_blk_config, size_max), &v); if (!err) - blk_queue_max_segment_size(vblk->disk->queue, v); + blk_queue_max_segment_size(q, v); else - blk_queue_max_segment_size(vblk->disk->queue, -1U); + blk_queue_max_segment_size(q, -1U); /* Host can optionally specify the block size of the device */ err = virtio_config_val(vdev, VIRTIO_BLK_F_BLK_SIZE, offsetof(struct virtio_blk_config, blk_size), &blk_size); if (!err) - blk_queue_logical_block_size(vblk->disk->queue, blk_size); + blk_queue_logical_block_size(q, blk_size); + else + blk_size = queue_logical_block_size(q); + + /* Use topology information if available */ + err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY, + offsetof(struct virtio_blk_config, physical_block_exp), + &physical_block_exp); + if (!err && physical_block_exp) + blk_queue_physical_block_size(q, + blk_size * (1 << physical_block_exp)); + + err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY, + offsetof(struct virtio_blk_config, alignment_offset), + &alignment_offset); + if (!err && alignment_offset) + blk_queue_alignment_offset(q, blk_size * alignment_offset); + + err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY, + offsetof(struct virtio_blk_config, min_io_size), + &min_io_size); + if (!err && min_io_size) + blk_queue_io_min(q, blk_size * min_io_size); + + err = virtio_config_val(vdev, VIRTIO_BLK_F_TOPOLOGY, + offsetof(struct virtio_blk_config, opt_io_size), + &opt_io_size); + if (!err && opt_io_size) + blk_queue_io_opt(q, blk_size * opt_io_size); + add_disk(vblk->disk); return 0; @@ -412,7 +443,7 @@ static struct virtio_device_id id_table[] = { static unsigned int features[] = { VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, - VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_FLUSH + VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY }; /* diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index e023682be2c..3141dd3b6e5 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -666,6 +666,14 @@ config VIRTIO_CONSOLE help Virtio console for use with lguest and other hypervisors. + Also serves as a general-purpose serial device for data + transfer between the guest and host. Character devices at + /dev/vportNpn will be created when corresponding ports are + found, where N is the device number and n is the port number + within that device. If specified by the host, a sysfs + attribute called 'name' will be populated with a name for + the port which can be used by udev scripts to create a + symlink to the device. config HVCS tristate "IBM Hypervisor Virtual Console Server support" diff --git a/drivers/char/hvc_beat.c b/drivers/char/hvc_beat.c index 0afc8b82212..6913fc33270 100644 --- a/drivers/char/hvc_beat.c +++ b/drivers/char/hvc_beat.c @@ -84,7 +84,7 @@ static int hvc_beat_put_chars(uint32_t vtermno, const char *buf, int cnt) return cnt; } -static struct hv_ops hvc_beat_get_put_ops = { +static const struct hv_ops hvc_beat_get_put_ops = { .get_chars = hvc_beat_get_chars, .put_chars = hvc_beat_put_chars, }; diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c index 416d3423150..d8dac5820f0 100644 --- a/drivers/char/hvc_console.c +++ b/drivers/char/hvc_console.c @@ -125,7 +125,7 @@ static struct hvc_struct *hvc_get_by_index(int index) * console interfaces but can still be used as a tty device. This has to be * static because kmalloc will not work during early console init. */ -static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; +static const struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] = {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1}; @@ -247,7 +247,7 @@ static void destroy_hvc_struct(struct kref *kref) * vty adapters do NOT get an hvc_instantiate() callback since they * appear after early console init. */ -int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops) +int hvc_instantiate(uint32_t vtermno, int index, const struct hv_ops *ops) { struct hvc_struct *hp; @@ -749,7 +749,8 @@ static const struct tty_operations hvc_ops = { }; struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int data, - struct hv_ops *ops, int outbuf_size) + const struct hv_ops *ops, + int outbuf_size) { struct hvc_struct *hp; int i; diff --git a/drivers/char/hvc_console.h b/drivers/char/hvc_console.h index 10950ca706d..52ddf4d3716 100644 --- a/drivers/char/hvc_console.h +++ b/drivers/char/hvc_console.h @@ -55,7 +55,7 @@ struct hvc_struct { int outbuf_size; int n_outbuf; uint32_t vtermno; - struct hv_ops *ops; + const struct hv_ops *ops; int irq_requested; int data; struct winsize ws; @@ -76,11 +76,12 @@ struct hv_ops { }; /* Register a vterm and a slot index for use as a console (console_init) */ -extern int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops); +extern int hvc_instantiate(uint32_t vtermno, int index, + const struct hv_ops *ops); /* register a vterm for hvc tty operation (module_init or hotplug add) */ extern struct hvc_struct * __devinit hvc_alloc(uint32_t vtermno, int data, - struct hv_ops *ops, int outbuf_size); + const struct hv_ops *ops, int outbuf_size); /* remove a vterm from hvc tty operation (module_exit or hotplug remove) */ extern int hvc_remove(struct hvc_struct *hp); diff --git a/drivers/char/hvc_iseries.c b/drivers/char/hvc_iseries.c index 936d05bf37f..fd0242676a2 100644 --- a/drivers/char/hvc_iseries.c +++ b/drivers/char/hvc_iseries.c @@ -197,7 +197,7 @@ done: return sent; } -static struct hv_ops hvc_get_put_ops = { +static const struct hv_ops hvc_get_put_ops = { .get_chars = get_chars, .put_chars = put_chars, .notifier_add = notifier_add_irq, diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c index fe62bd0e17b..21681a81cc3 100644 --- a/drivers/char/hvc_iucv.c +++ b/drivers/char/hvc_iucv.c @@ -922,7 +922,7 @@ static int hvc_iucv_pm_restore_thaw(struct device *dev) /* HVC operations */ -static struct hv_ops hvc_iucv_ops = { +static const struct hv_ops hvc_iucv_ops = { .get_chars = hvc_iucv_get_chars, .put_chars = hvc_iucv_put_chars, .notifier_add = hvc_iucv_notifier_add, diff --git a/drivers/char/hvc_rtas.c b/drivers/char/hvc_rtas.c index 88590d04004..61c4a61558d 100644 --- a/drivers/char/hvc_rtas.c +++ b/drivers/char/hvc_rtas.c @@ -71,7 +71,7 @@ static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count) return i; } -static struct hv_ops hvc_rtas_get_put_ops = { +static const struct hv_ops hvc_rtas_get_put_ops = { .get_chars = hvc_rtas_read_console, .put_chars = hvc_rtas_write_console, }; diff --git a/drivers/char/hvc_udbg.c b/drivers/char/hvc_udbg.c index bd63ba878a5..b0957e61a7b 100644 --- a/drivers/char/hvc_udbg.c +++ b/drivers/char/hvc_udbg.c @@ -58,7 +58,7 @@ static int hvc_udbg_get(uint32_t vtermno, char *buf, int count) return i; } -static struct hv_ops hvc_udbg_ops = { +static const struct hv_ops hvc_udbg_ops = { .get_chars = hvc_udbg_get, .put_chars = hvc_udbg_put, }; diff --git a/drivers/char/hvc_vio.c b/drivers/char/hvc_vio.c index 10be343d6ae..27370e99c66 100644 --- a/drivers/char/hvc_vio.c +++ b/drivers/char/hvc_vio.c @@ -77,7 +77,7 @@ static int filtered_get_chars(uint32_t vtermno, char *buf, int count) return got; } -static struct hv_ops hvc_get_put_ops = { +static const struct hv_ops hvc_get_put_ops = { .get_chars = filtered_get_chars, .put_chars = hvc_put_chars, .notifier_add = notifier_add_irq, diff --git a/drivers/char/hvc_xen.c b/drivers/char/hvc_xen.c index b1a71638c77..60446f82a3f 100644 --- a/drivers/char/hvc_xen.c +++ b/drivers/char/hvc_xen.c @@ -122,7 +122,7 @@ static int read_console(uint32_t vtermno, char *buf, int len) return recv; } -static struct hv_ops hvc_ops = { +static const struct hv_ops hvc_ops = { .get_chars = read_console, .put_chars = write_console, .notifier_add = notifier_add_irq, diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index a035ae39a35..213373b5f17 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1,18 +1,6 @@ -/*D:300 - * The Guest console driver - * - * Writing console drivers is one of the few remaining Dark Arts in Linux. - * Fortunately for us, the path of virtual consoles has been well-trodden by - * the PowerPC folks, who wrote "hvc_console.c" to generically support any - * virtual console. We use that infrastructure which only requires us to write - * the basic put_chars and get_chars functions and call the right register - * functions. - :*/ - -/*M:002 The console can be flooded: while the Guest is processing input the - * Host can send more. Buffering in the Host could alleviate this, but it is a - * difficult problem in general. :*/ -/* Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation +/* + * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation + * Copyright (C) 2009, 2010 Red Hat, Inc. * * 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 @@ -28,142 +16,694 @@ * 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/device.h> #include <linux/err.h> +#include <linux/fs.h> #include <linux/init.h> +#include <linux/list.h> +#include <linux/poll.h> +#include <linux/sched.h> +#include <linux/spinlock.h> #include <linux/virtio.h> #include <linux/virtio_console.h> +#include <linux/wait.h> +#include <linux/workqueue.h> #include "hvc_console.h" -/*D:340 These represent our input and output console queues, and the virtio - * operations for them. */ -static struct virtqueue *in_vq, *out_vq; -static struct virtio_device *vdev; +/* + * 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; + + /* Number of devices this driver is handling */ + unsigned int index; + + /* + * 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; + +DEFINE_SPINLOCK(pdrvdata_lock); + +/* 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; + + /* + * 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; +}; + +/* + * This is a per-device struct that stores data common to all the + * ports for that device (vdev->priv). + */ +struct ports_device { + /* + * 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 cvq_lock; + + /* The current config space is stored here */ + struct virtio_console_config config; + + /* 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; + + /* Array of per-port IO virtqueues */ + struct virtqueue **in_vqs, **out_vqs; + + /* Used for numbering devices for sysfs and debugfs */ + unsigned int drv_index; + + /* Major number for this device. Ports will be created as minors. */ + int chr_major; +}; + +/* 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; + + /* 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; + + /* + * 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; + + /* 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; + + /* The 'id' to identify the port with the Host */ + u32 id; + + /* 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_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 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 0; + return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT); +} -/* This is our input buffer, and how much data is left in it. */ -static unsigned int in_len; -static char *in, *inbuf; +static void free_buf(struct port_buffer *buf) +{ + kfree(buf->buf); + kfree(buf); +} + +static struct port_buffer *alloc_buf(size_t buf_size) +{ + struct port_buffer *buf; -/* The operations for our console. */ -static struct hv_ops virtio_cons; + buf = kmalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + goto fail; + buf->buf = kzalloc(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 void *get_inbuf(struct port *port) +{ + struct port_buffer *buf; + struct virtqueue *vq; + unsigned int len; -/* The hvc device */ -static struct hvc_struct *hvc; + vq = port->in_vq; + buf = vq->vq_ops->get_buf(vq, &len); + if (buf) { + buf->len = len; + buf->offset = 0; + } + return buf; +} -/*D:310 The put_chars() callback is pretty straightforward. +/* + * Create a scatter-gather list representing our input buffer and put + * it in the queue. * - * 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 (lguest's Launcher does). */ -static int put_chars(u32 vtermno, const char *buf, int count) + * 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 = vq->vq_ops->add_buf(vq, sg, 0, 1, buf); + vq->vq_ops->kick(vq); + return ret; +} + +/* Discard any unread data this port has. Callers lockers. */ +static void discard_port_data(struct port *port) +{ + struct port_buffer *buf; + struct virtqueue *vq; unsigned int len; + int ret; - /* This is a convenient routine to initialize a single-elem sg list */ - sg_init_one(sg, buf, count); + vq = port->in_vq; + if (port->inbuf) + buf = port->inbuf; + else + buf = vq->vq_ops->get_buf(vq, &len); - /* add_buf wants a token to identify this buffer: we hand it any - * non-NULL pointer, since there's only ever one buffer. */ - if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) >= 0) { - /* Tell Host to go! */ - out_vq->vq_ops->kick(out_vq); - /* Chill out until it's done with the buffer. */ - while (!out_vq->vq_ops->get_buf(out_vq, &len)) - cpu_relax(); + ret = 0; + while (buf) { + if (add_inbuf(vq, buf) < 0) { + ret++; + free_buf(buf); + } + buf = vq->vq_ops->get_buf(vq, &len); } + port->inbuf = NULL; + if (ret) + dev_warn(port->dev, "Errors adding %d buffers back to vq\n", + ret); +} - /* We're expected to return the amount of data we wrote: all of it. */ - return count; +static bool port_has_data(struct port *port) +{ + unsigned long flags; + bool ret; + + spin_lock_irqsave(&port->inbuf_lock, flags); + if (port->inbuf) { + ret = true; + goto out; + } + port->inbuf = get_inbuf(port); + if (port->inbuf) { + ret = true; + goto out; + } + ret = false; +out: + spin_unlock_irqrestore(&port->inbuf_lock, flags); + return ret; } -/* Create a scatter-gather list representing our input buffer and put it in the - * queue. */ -static void add_inbuf(void) +static ssize_t send_control_msg(struct port *port, unsigned int event, + unsigned int value) { struct scatterlist sg[1]; - sg_init_one(sg, inbuf, PAGE_SIZE); + struct virtio_console_control cpkt; + struct virtqueue *vq; + int len; + + if (!use_multiport(port->portdev)) + return 0; + + cpkt.id = port->id; + cpkt.event = event; + cpkt.value = value; + + vq = port->portdev->c_ovq; - /* We should always be able to add one buffer to an empty queue. */ - if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) < 0) - BUG(); - in_vq->vq_ops->kick(in_vq); + sg_init_one(sg, &cpkt, sizeof(cpkt)); + if (vq->vq_ops->add_buf(vq, sg, 1, 0, &cpkt) >= 0) { + vq->vq_ops->kick(vq); + while (!vq->vq_ops->get_buf(vq, &len)) + cpu_relax(); + } + return 0; } -/*D:350 get_chars() is the callback from the hvc_console infrastructure when - * an interrupt is received. - * - * Most of the code deals with the fact that the hvc_console() infrastructure - * only asks us for 16 bytes at a time. We keep in_offset and in_used fields - * for partially-filled buffers. */ -static int get_chars(u32 vtermno, char *buf, int count) +static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count) { - /* If we don't have an input queue yet, we can't get input. */ - BUG_ON(!in_vq); + struct scatterlist sg[1]; + struct virtqueue *out_vq; + ssize_t ret; + unsigned int len; + + out_vq = port->out_vq; + + sg_init_one(sg, in_buf, in_count); + ret = out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, in_buf); + + /* Tell Host to go! */ + out_vq->vq_ops->kick(out_vq); + + if (ret < 0) { + len = 0; + goto fail; + } + + /* + * Wait till the host acknowledges it pushed out the data we + * sent. Also ensure we return to userspace the number of + * bytes that were successfully consumed by the host. + */ + while (!out_vq->vq_ops->get_buf(out_vq, &len)) + cpu_relax(); +fail: + /* We're expected to return the amount of data we wrote */ + return len; +} + +/* + * Give out the data that's requested from the buffer that we have + * queued up. + */ +static ssize_t fill_readbuf(struct port *port, char *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(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; +} - /* No buffer? Try to get one. */ - if (!in_len) { - in = in_vq->vq_ops->get_buf(in_vq, &in_len); - if (!in) +/* The condition that must be true for polling to end */ +static bool wait_is_over(struct port *port) +{ + return port_has_data(port) || !port->host_connected; +} + +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; + + 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_interruptible(port->waitqueue, + wait_is_over(port)); + if (ret < 0) + return ret; + } + /* + * 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 ssize_t port_fops_write(struct file *filp, const char __user *ubuf, + size_t count, loff_t *offp) +{ + struct port *port; + char *buf; + ssize_t ret; + + port = filp->private_data; + + count = min((size_t)(32 * 1024), count); + + buf = kmalloc(count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + ret = copy_from_user(buf, ubuf, count); + if (ret) { + ret = -EFAULT; + goto free_buf; } - /* You want more than we have to give? Well, try wanting less! */ - if (in_len < count) - count = in_len; + ret = send_buf(port, buf, count); +free_buf: + kfree(buf); + return ret; +} + +static unsigned int port_fops_poll(struct file *filp, poll_table *wait) +{ + struct port *port; + unsigned int ret; + + port = filp->private_data; + poll_wait(filp, &port->waitqueue, wait); + + ret = 0; + if (port->inbuf) + ret |= POLLIN | POLLRDNORM; + if (port->host_connected) + ret |= POLLOUT; + if (!port->host_connected) + ret |= POLLHUP; + + return ret; +} + +static int port_fops_release(struct inode *inode, struct file *filp) +{ + struct port *port |