diff options
Diffstat (limited to 'drivers/char/hvc_iucv.c')
| -rw-r--r-- | drivers/char/hvc_iucv.c | 211 |
1 files changed, 174 insertions, 37 deletions
diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c index a80d92233169..a23f7e8fba86 100644 --- a/drivers/char/hvc_iucv.c +++ b/drivers/char/hvc_iucv.c @@ -12,9 +12,11 @@ #include <linux/types.h> #include <asm/ebcdic.h> +#include <linux/delay.h> #include <linux/mempool.h> #include <linux/module.h> #include <linux/tty.h> +#include <linux/wait.h> #include <net/iucv/iucv.h> #include "hvc_console.h" @@ -37,7 +39,7 @@ struct iucv_tty_msg { u8 version; /* Message version */ u8 type; /* Message type */ -#define MSG_MAX_DATALEN (~(u16)0) +#define MSG_MAX_DATALEN ((u16)(~0)) u16 datalen; /* Payload length */ u8 data[]; /* Payload buffer */ } __attribute__((packed)); @@ -60,6 +62,12 @@ struct hvc_iucv_private { enum tty_state_t tty_state; /* TTY status */ struct iucv_path *path; /* IUCV path pointer */ spinlock_t lock; /* hvc_iucv_private lock */ +#define SNDBUF_SIZE (PAGE_SIZE) /* must be < MSG_MAX_DATALEN */ + void *sndbuf; /* send buffer */ + size_t sndbuf_len; /* length of send buffer */ +#define QUEUE_SNDBUF_DELAY (HZ / 25) + struct delayed_work sndbuf_work; /* work: send iucv msg(s) */ + wait_queue_head_t sndbuf_waitq; /* wait for send completion */ struct list_head tty_outqueue; /* outgoing IUCV messages */ struct list_head tty_inqueue; /* incoming IUCV messages */ }; @@ -318,57 +326,118 @@ static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) } /** - * hvc_iucv_send() - Send an IUCV message containing terminal data. + * hvc_iucv_queue() - Buffer terminal data for sending. * @priv: Pointer to struct hvc_iucv_private instance. * @buf: Buffer containing data to send. - * @size: Size of buffer and amount of data to send. + * @count: Size of buffer and amount of data to send. * - * If an IUCV communication path is established, the function copies the buffer - * data to a newly allocated struct iucv_tty_buffer element, sends the data and - * puts the element to the outqueue. + * The function queues data for sending. To actually send the buffered data, + * a work queue function is * scheduled (with QUEUE_SNDBUF_DELAY). + * The function returns the number of data bytes that has been buffered. * - * If there is no IUCV communication path established, the function returns 0. + * If the device is not connected, data is ignored and the function returns + * @count. + * If the buffer is full, the function returns 0. * If an existing IUCV communicaton path has been severed, the function returns * -EPIPE (can be passed to HVC layer to cause a tty hangup). */ -static int hvc_iucv_send(struct hvc_iucv_private *priv, const char *buf, +static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf, int count) { + size_t len; + + if (priv->iucv_state == IUCV_DISCONN) + return count; /* ignore data */ + + if (priv->iucv_state == IUCV_SEVERED) + return -EPIPE; + + len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len); + if (!len) + return 0; + + memcpy(priv->sndbuf + priv->sndbuf_len, buf, len); + priv->sndbuf_len += len; + + if (priv->iucv_state == IUCV_CONNECTED) + schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY); + + return len; +} + +/** + * hvc_iucv_send() - Send an IUCV message containing terminal data. + * @priv: Pointer to struct hvc_iucv_private instance. + * + * If an IUCV communication path has been established, the queued data + * for output are sent via an IUCV message. + * + * If there is no IUCV communication path established, the function returns 0. + * If an existing IUCV communicaton path has been severed, the function returns + * -EPIPE. + */ +static int hvc_iucv_send(struct hvc_iucv_private *priv) +{ struct iucv_tty_buffer *sb; - int rc; - u16 len; + int rc, len; if (priv->iucv_state == IUCV_SEVERED) return -EPIPE; if (priv->iucv_state == IUCV_DISCONN) - return 0; + return -EIO; - len = min_t(u16, MSG_MAX_DATALEN, count); + if (!priv->sndbuf_len) + return 0; /* allocate internal buffer to store msg data and also compute total * message length */ - sb = alloc_tty_buffer(len, GFP_ATOMIC); + sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC); if (!sb) return -ENOMEM; - sb->mbuf->datalen = len; - memcpy(sb->mbuf->data, buf, len); + memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len); + sb->mbuf->datalen = (u16) priv->sndbuf_len; + sb->msg.length = MSG_SIZE(sb->mbuf->datalen); list_add_tail(&sb->list, &priv->tty_outqueue); rc = __iucv_message_send(priv->path, &sb->msg, 0, 0, (void *) sb->mbuf, sb->msg.length); if (rc) { + /* drop the message here; however we might want to handle + * 0x03 (msg limit reached) by trying again... */ list_del(&sb->list); destroy_tty_buffer(sb); - len = 0; } + len = priv->sndbuf_len; + priv->sndbuf_len = 0; return len; } /** + * hvc_iucv_sndbuf_work() - Send buffered data over IUCV + * @work: Work structure. + * + * The function sends buffered output data over IUCV and, if necessary, + * reschedules itself if not all buffered data could be sent. + */ +static void hvc_iucv_sndbuf_work(struct work_struct *work) +{ + struct hvc_iucv_private *priv; + + priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work); + + if (!priv) + return; + + spin_lock_bh(&priv->lock); + hvc_iucv_send(priv); + spin_unlock_bh(&priv->lock); +} + +/** * hvc_iucv_put_chars() - HVC put_chars operation. * @vtermno: HVC virtual terminal number. * @buf: Pointer to an buffer to read data from @@ -385,7 +454,7 @@ static int hvc_iucv_send(struct hvc_iucv_private *priv, const char *buf, static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count) { struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); - int sent; + int queued; if (count <= 0) return 0; @@ -394,10 +463,10 @@ static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count) return -ENODEV; spin_lock(&priv->lock); - sent = hvc_iucv_send(priv, buf, count); + queued = hvc_iucv_queue(priv, buf, count); spin_unlock(&priv->lock); - return sent; + return queued; } /** @@ -441,6 +510,46 @@ static void hvc_iucv_cleanup(struct hvc_iucv_private *priv) priv->tty_state = TTY_CLOSED; priv->iucv_state = IUCV_DISCONN; + + priv->sndbuf_len = 0; +} + +/** + * tty_outqueue_empty() - Test if the tty outq is empty + * @priv: Pointer to struct hvc_iucv_private instance. + */ +static inline int tty_outqueue_empty(struct hvc_iucv_private *priv) +{ + int rc; + + spin_lock_bh(&priv->lock); + rc = list_empty(&priv->tty_outqueue); + spin_unlock_bh(&priv->lock); + + return rc; +} + +/** + * flush_sndbuf_sync() - Flush send buffer and wait for completion + * @priv: Pointer to struct hvc_iucv_private instance. + * + * The routine cancels a pending sndbuf work, calls hvc_iucv_send() + * to flush any buffered terminal output data and waits for completion. + */ +static void flush_sndbuf_sync(struct hvc_iucv_private *priv) +{ + int sync_wait; + + cancel_delayed_work_sync(&priv->sndbuf_work); + + spin_lock_bh(&priv->lock); + hvc_iucv_send(priv); /* force sending buffered data */ + sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */ + spin_unlock_bh(&priv->lock); + + if (sync_wait) + wait_event_timeout(priv->sndbuf_waitq, + tty_outqueue_empty(priv), HZ); } /** @@ -471,6 +580,8 @@ static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) if (!priv) return; + flush_sndbuf_sync(priv); + spin_lock_bh(&priv->lock); /* NOTE: If the hangup was scheduled by ourself (from the iucv * path_servered callback [IUCV_SEVERED]), then we have to @@ -510,6 +621,8 @@ static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) if (!priv) return; + flush_sndbuf_sync(priv); + spin_lock_bh(&priv->lock); path = priv->path; /* save reference to IUCV path */ priv->path = NULL; @@ -588,6 +701,9 @@ static int hvc_iucv_path_pending(struct iucv_path *path, priv->path = path; priv->iucv_state = IUCV_CONNECTED; + /* flush buffered output data... */ + schedule_delayed_work(&priv->sndbuf_work, 5); + out_path_handled: spin_unlock(&priv->lock); return 0; @@ -615,15 +731,18 @@ static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16]) spin_lock(&priv->lock); priv->iucv_state = IUCV_SEVERED; - /* NOTE: If the tty has not yet been opened by a getty program - * (e.g. to see console messages), then cleanup the - * hvc_iucv_private structure to allow re-connects. + /* If the tty has not yet been opened, clean up the hvc_iucv_private + * structure to allow re-connects. * - * If the tty has been opened, the get_chars() callback returns - * -EPIPE to signal the hvc console layer to hang up the tty. */ + * If it has been opened, let get_chars() return -EPIPE to signal the + * HVC layer to hang up the tty. + * If so, we need to wake up the HVC thread to call get_chars()... + */ priv->path = NULL; if (priv->tty_state == TTY_CLOSED) hvc_iucv_cleanup(priv); + else + hvc_kick(); spin_unlock(&priv->lock); /* finally sever path (outside of priv->lock due to lock ordering) */ @@ -648,6 +767,12 @@ static void hvc_iucv_msg_pending(struct iucv_path *path, struct hvc_iucv_private *priv = path->private; struct iucv_tty_buffer *rb; + /* reject messages that exceed max size of iucv_tty_msg->datalen */ + if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) { + iucv_message_reject(path, msg); + return; + } + spin_lock(&priv->lock); /* reject messages if tty has not yet been opened */ @@ -656,7 +781,7 @@ static void hvc_iucv_msg_pending(struct iucv_path *path, goto unlock_return; } - /* allocate buffer an empty buffer element */ + /* allocate tty buffer to save iucv msg only */ rb = alloc_tty_buffer(0, GFP_ATOMIC); if (!rb) { iucv_message_reject(path, msg); @@ -666,7 +791,7 @@ static void hvc_iucv_msg_pending(struct iucv_path *path, list_add_tail(&rb->list, &priv->tty_inqueue); - hvc_kick(); /* wakup hvc console thread */ + hvc_kick(); /* wake up hvc console thread */ unlock_return: spin_unlock(&priv->lock); @@ -697,6 +822,7 @@ static void hvc_iucv_msg_complete(struct iucv_path *path, list_move(&ent->list, &list_remove); break; } + wake_up(&priv->sndbuf_waitq); spin_unlock(&priv->lock); destroy_tty_buffer_list(&list_remove); } @@ -732,16 +858,28 @@ static int __init hvc_iucv_alloc(int id) spin_lock_init(&priv->lock); INIT_LIST_HEAD(&priv->tty_outqueue); INIT_LIST_HEAD(&priv->tty_inqueue); + INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work); + init_waitqueue_head(&priv->sndbuf_waitq); + + priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL); + if (!priv->sndbuf) { + kfree(priv); + return -ENOMEM; + } /* Finally allocate hvc */ - priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, - HVC_IUCV_MAGIC + id, &hvc_iucv_ops, PAGE_SIZE); + priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */ + HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256); if (IS_ERR(priv->hvc)) { rc = PTR_ERR(priv->hvc); + free_page((unsigned long) priv->sndbuf); kfree(priv); return rc; } + /* kick khvcd thread; instead of using polling */ + priv->hvc->irq_requested = 1; + /* setup iucv related information */ snprintf(name, 9, "lnxhvc%-2d", id); memcpy(priv->srv_name, name, 8); @@ -759,8 +897,8 @@ static int __init hvc_iucv_init(void) int rc, i; if (!MACHINE_IS_VM) { - pr_warning("The z/VM IUCV Hypervisor console cannot be " - "used without z/VM.\n"); + pr_info("The z/VM IUCV HVC device driver cannot " + "be used without z/VM\n"); return -ENODEV; } @@ -774,16 +912,14 @@ static int __init hvc_iucv_init(void) sizeof(struct iucv_tty_buffer), 0, 0, NULL); if (!hvc_iucv_buffer_cache) { - pr_err("Not enough memory for driver initialization " - "(rs=%d).\n", 1); + pr_err("Allocating memory failed with reason code=%d\n", 1); return -ENOMEM; } hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR, hvc_iucv_buffer_cache); if (!hvc_iucv_mempool) { - pr_err("Not enough memory for driver initialization " - "(rs=%d).\n", 2); + pr_err("Allocating memory failed with reason code=%d\n", 2); kmem_cache_destroy(hvc_iucv_buffer_cache); return -ENOMEM; } @@ -792,8 +928,8 @@ static int __init hvc_iucv_init(void) for (i = 0; i < hvc_iucv_devices; i++) { rc = hvc_iucv_alloc(i); if (rc) { - pr_err("Could not create new z/VM IUCV HVC backend " - "rc=%d.\n", rc); + pr_err("Creating a new HVC terminal device " + "failed with error code=%d\n", rc); goto out_error_hvc; } } @@ -801,7 +937,8 @@ static int __init hvc_iucv_init(void) /* register IUCV callback handler */ rc = iucv_register(&hvc_iucv_handler, 0); if (rc) { - pr_err("Could not register iucv handler (rc=%d).\n", rc); + pr_err("Registering IUCV handlers failed with error code=%d\n", + rc); goto out_error_iucv; } |
