From 2dc184c0ba5c8661649ed2ca0b9e97ed49860cb5 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Fri, 9 Jan 2009 12:14:57 +0100 Subject: [S390] hvc_iucv: Change IUCV term id and use one device as default The patch renames the IUCV application ID from "ihvc" to "lnxhvc". The device driver allocates one IUCV terminal device (lnxhvc0) as default. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- drivers/char/hvc_iucv.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c index 5ea7d7713fc..a80d9223316 100644 --- a/drivers/char/hvc_iucv.c +++ b/drivers/char/hvc_iucv.c @@ -78,8 +78,8 @@ static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *); static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *); -/* Kernel module parameters */ -static unsigned long hvc_iucv_devices; +/* Kernel module parameter: use one terminal device as default */ +static unsigned long hvc_iucv_devices = 1; /* Array of allocated hvc iucv tty lines... */ static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; @@ -743,7 +743,7 @@ static int __init hvc_iucv_alloc(int id) } /* setup iucv related information */ - snprintf(name, 9, "ihvc%-4d", id); + snprintf(name, 9, "lnxhvc%-2d", id); memcpy(priv->srv_name, name, 8); ASCEBC(priv->srv_name, 8); -- cgit v1.2.3 From c45ce4b5774498ae919f6219c751e824a7196e2b Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Fri, 9 Jan 2009 12:14:58 +0100 Subject: [S390] hvc_iucv: Limit rate of outgoing IUCV messages This patch introduces a send buffer to limit outgoing IUCV messages up to a maximum of 25 IUCV messages per second. If no communication path to a IUCV HVC terminal exist, any data written to the terminal is discarded. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- drivers/char/hvc_iucv.c | 211 +++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 174 insertions(+), 37 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c index a80d9223316..a23f7e8fba8 100644 --- a/drivers/char/hvc_iucv.c +++ b/drivers/char/hvc_iucv.c @@ -12,9 +12,11 @@ #include #include +#include #include #include #include +#include #include #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 */ }; @@ -318,56 +326,117 @@ 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. @@ -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; } -- cgit v1.2.3 From 17e19f04ac73df05854ba2e7e945d51c494a3011 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Fri, 9 Jan 2009 12:14:59 +0100 Subject: [S390] hvc_iucv: Update function documentation Update documentation of functions. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- drivers/char/hvc_iucv.c | 176 +++++++++++++++++++++--------------------------- 1 file changed, 75 insertions(+), 101 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c index a23f7e8fba8..ce1a25f779c 100644 --- a/drivers/char/hvc_iucv.c +++ b/drivers/char/hvc_iucv.c @@ -1,14 +1,15 @@ /* - * hvc_iucv.c - z/VM IUCV back-end for the Hypervisor Console (HVC) + * hvc_iucv.c - z/VM IUCV hypervisor console (HVC) device driver * - * This back-end for HVC provides terminal access via + * This HVC device driver provides terminal access using * z/VM IUCV communication paths. * - * Copyright IBM Corp. 2008. + * Copyright IBM Corp. 2008 * * Author(s): Hendrik Brueckner */ #define KMSG_COMPONENT "hvc_iucv" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include #include @@ -22,7 +23,7 @@ #include "hvc_console.h" -/* HVC backend for z/VM IUCV */ +/* General device driver settings */ #define HVC_IUCV_MAGIC 0xc9e4c3e5 #define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS #define MEMPOOL_MIN_NR (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4) @@ -35,7 +36,6 @@ #define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */ #define MSG_TYPE_DATA 0x10 /* Terminal data */ -#define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data)) struct iucv_tty_msg { u8 version; /* Message version */ u8 type; /* Message type */ @@ -43,6 +43,7 @@ struct iucv_tty_msg { u16 datalen; /* Payload length */ u8 data[]; /* Payload buffer */ } __attribute__((packed)); +#define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data)) enum iucv_state_t { IUCV_DISCONN = 0, @@ -56,7 +57,7 @@ enum tty_state_t { }; struct hvc_iucv_private { - struct hvc_struct *hvc; /* HVC console struct reference */ + struct hvc_struct *hvc; /* HVC struct reference */ u8 srv_name[8]; /* IUCV service name (ebcdic) */ enum iucv_state_t iucv_state; /* IUCV connection status */ enum tty_state_t tty_state; /* TTY status */ @@ -74,7 +75,7 @@ struct hvc_iucv_private { struct iucv_tty_buffer { struct list_head list; /* list pointer */ - struct iucv_message msg; /* store an incoming IUCV message */ + struct iucv_message msg; /* store an IUCV message */ size_t offset; /* data buffer offset */ struct iucv_tty_msg *mbuf; /* buffer to store input/output data */ }; @@ -120,7 +121,7 @@ struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) } /** - * alloc_tty_buffer() - Returns a new struct iucv_tty_buffer element. + * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element. * @size: Size of the internal buffer used to store data. * @flags: Memory allocation flags passed to mempool. * @@ -128,7 +129,6 @@ struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) * allocates an internal data buffer with the specified size @size. * Note: The total message size arises from the internal buffer size and the * members of the iucv_tty_msg structure. - * * The function returns NULL if memory allocation has failed. */ static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags) @@ -157,9 +157,6 @@ static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags) /** * destroy_tty_buffer() - destroy struct iucv_tty_buffer element. * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL. - * - * The destroy_tty_buffer() function frees the internal data buffer and returns - * the struct iucv_tty_buffer element back to the mempool for freeing. */ static void destroy_tty_buffer(struct iucv_tty_buffer *bufp) { @@ -169,11 +166,7 @@ static void destroy_tty_buffer(struct iucv_tty_buffer *bufp) /** * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element. - * @list: List head pointer to a list containing struct iucv_tty_buffer - * elements. - * - * Calls destroy_tty_buffer() for each struct iucv_tty_buffer element in the - * list @list. + * @list: List containing struct iucv_tty_buffer elements. */ static void destroy_tty_buffer_list(struct list_head *list) { @@ -186,24 +179,24 @@ static void destroy_tty_buffer_list(struct list_head *list) } /** - * hvc_iucv_write() - Receive IUCV message write data to HVC console buffer. - * @priv: Pointer to hvc_iucv_private structure. - * @buf: HVC console buffer for writing received terminal data. - * @count: HVC console buffer size. + * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer. + * @priv: Pointer to struct hvc_iucv_private + * @buf: HVC buffer for writing received terminal data. + * @count: HVC buffer size. * @has_more_data: Pointer to an int variable. * * The function picks up pending messages from the input queue and receives * the message data that is then written to the specified buffer @buf. - * If the buffer size @count is less than the data message size, then the + * If the buffer size @count is less than the data message size, the * message is kept on the input queue and @has_more_data is set to 1. - * If the message data has been entirely written, the message is removed from + * If all message data has been written, the message is removed from * the input queue. * * The function returns the number of bytes written to the terminal, zero if * there are no pending data messages available or if there is no established * IUCV path. * If the IUCV path has been severed, then -EPIPE is returned to cause a - * hang up (that is issued by the HVC console layer). + * hang up (that is issued by the HVC layer). */ static int hvc_iucv_write(struct hvc_iucv_private *priv, char *buf, int count, int *has_more_data) @@ -212,12 +205,12 @@ static int hvc_iucv_write(struct hvc_iucv_private *priv, int written; int rc; - /* Immediately return if there is no IUCV connection */ + /* immediately return if there is no IUCV connection */ if (priv->iucv_state == IUCV_DISCONN) return 0; - /* If the IUCV path has been severed, return -EPIPE to inform the - * hvc console layer to hang up the tty device. */ + /* if the IUCV path has been severed, return -EPIPE to inform the + * HVC layer to hang up the tty device. */ if (priv->iucv_state == IUCV_SEVERED) return -EPIPE; @@ -225,7 +218,7 @@ static int hvc_iucv_write(struct hvc_iucv_private *priv, if (list_empty(&priv->tty_inqueue)) return 0; - /* receive a iucv message and flip data to the tty (ldisc) */ + /* receive an iucv message and flip data to the tty (ldisc) */ rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list); written = 0; @@ -268,7 +261,7 @@ static int hvc_iucv_write(struct hvc_iucv_private *priv, case MSG_TYPE_WINSIZE: if (rb->mbuf->datalen != sizeof(struct winsize)) break; - hvc_resize(priv->hvc, *((struct winsize *)rb->mbuf->data)); + hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data)); break; case MSG_TYPE_ERROR: /* ignored ... */ @@ -292,10 +285,9 @@ out_written: * @buf: Pointer to a buffer to store data * @count: Size of buffer available for writing * - * The hvc_console thread calls this method to read characters from - * the terminal backend. If an IUCV communication path has been established, - * pending IUCV messages are received and data is copied into buffer @buf - * up to @count bytes. + * The HVC thread calls this method to read characters from the back-end. + * If an IUCV communication path has been established, pending IUCV messages + * are received and data is copied into buffer @buf up to @count bytes. * * Locking: The routine gets called under an irqsave() spinlock; and * the routine locks the struct hvc_iucv_private->lock to call @@ -332,17 +324,17 @@ static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) * @count: Size of buffer and amount of data to send. * * The function queues data for sending. To actually send the buffered data, - * a work queue function is * scheduled (with QUEUE_SNDBUF_DELAY). + * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY). * The function returns the number of data bytes that has been buffered. * * 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). + * If an existing IUCV communicaton path has been severed, -EPIPE is returned + * (that can be passed to HVC layer to cause a tty hangup). */ static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf, - int count) + int count) { size_t len; @@ -369,12 +361,10 @@ static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf, * 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. + * If an IUCV communication path has been established, the buffered output data + * is sent via an IUCV message and the number of bytes sent is returned. + * Returns 0 if there is no established IUCV communication path or + * -EPIPE if an existing IUCV communicaton path has been severed. */ static int hvc_iucv_send(struct hvc_iucv_private *priv) { @@ -420,15 +410,14 @@ static int hvc_iucv_send(struct hvc_iucv_private *priv) * 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. + * This work queue function sends buffered output data over IUCV and, + * if not all buffered data could be sent, reschedules itself. */ 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; @@ -443,10 +432,8 @@ static void hvc_iucv_sndbuf_work(struct work_struct *work) * @buf: Pointer to an buffer to read data from * @count: Size of buffer available for reading * - * The hvc_console thread calls this method to write characters from - * to the terminal backend. - * The function calls hvc_iucv_send() under the lock of the - * struct hvc_iucv_private instance that corresponds to the tty @vtermno. + * The HVC thread calls this method to write characters to the back-end. + * The function calls hvc_iucv_queue() to queue terminal data for sending. * * Locking: The method gets called under an irqsave() spinlock; and * locks struct hvc_iucv_private->lock. @@ -496,12 +483,8 @@ static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id) } /** - * hvc_iucv_cleanup() - Clean up function if the tty portion is finally closed. + * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance. * @priv: Pointer to the struct hvc_iucv_private instance. - * - * The functions severs the established IUCV communication path (if any), and - * destroy struct iucv_tty_buffer elements from the in- and outqueue. Finally, - * the functions resets the states to TTY_CLOSED and IUCV_DISCONN. */ static void hvc_iucv_cleanup(struct hvc_iucv_private *priv) { @@ -553,22 +536,19 @@ static void flush_sndbuf_sync(struct hvc_iucv_private *priv) } /** - * hvc_iucv_notifier_hangup() - HVC notifier for tty hangups. - * @hp: Pointer to the HVC device (struct hvc_struct) - * @id: Additional data (originally passed to hvc_alloc): the index of an struct - * hvc_iucv_private instance. + * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups. + * @hp: Pointer to the HVC device (struct hvc_struct) + * @id: Additional data (originally passed to hvc_alloc): + * the index of an struct hvc_iucv_private instance. * - * This routine notifies the HVC backend that a tty hangup (carrier loss, + * This routine notifies the HVC back-end that a tty hangup (carrier loss, * virtual or otherwise) has occured. - * - * The HVC backend for z/VM IUCV ignores virtual hangups (vhangup()), to keep - * an existing IUCV communication path established. + * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup()) + * to keep an existing IUCV communication path established. * (Background: vhangup() is called from user space (by getty or login) to * disable writing to the tty by other applications). - * - * If the tty has been opened (e.g. getty) and an established IUCV path has been - * severed (we caused the tty hangup in that case), then the functions invokes - * hvc_iucv_cleanup() to clean up. + * If the tty has been opened and an established IUCV path has been severed + * (we caused the tty hangup), the function calls hvc_iucv_cleanup(). * * Locking: struct hvc_iucv_private->lock */ @@ -584,10 +564,8 @@ static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) 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 - * finally clean up the tty backend structure and set state to - * TTY_CLOSED. - * + * path_servered callback [IUCV_SEVERED]), we have to clean up + * our structure and to set state to TTY_CLOSED. * If the tty was hung up otherwise (e.g. vhangup()), then we * ignore this hangup and keep an established IUCV path open... * (...the reason is that we are not able to connect back to the @@ -605,10 +583,9 @@ static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) * @id: Additional data (originally passed to hvc_alloc): * the index of an struct hvc_iucv_private instance. * - * This routine notifies the HVC backend that the last tty device file - * descriptor has been closed. - * The function calls hvc_iucv_cleanup() to clean up the struct hvc_iucv_private - * instance. + * This routine notifies the HVC back-end that the last tty device fd has been + * closed. The function calls hvc_iucv_cleanup() to clean up the struct + * hvc_iucv_private instance. * * Locking: struct hvc_iucv_private->lock */ @@ -640,20 +617,18 @@ static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) /** * hvc_iucv_path_pending() - IUCV handler to process a connection request. * @path: Pending path (struct iucv_path) - * @ipvmid: Originator z/VM system identifier + * @ipvmid: z/VM system identifier of originator * @ipuser: User specified data for this path * (AF_IUCV: port/service name and originator port) * - * The function uses the @ipuser data to check to determine if the pending - * path belongs to a terminal managed by this HVC backend. - * If the check is successful, then an additional check is done to ensure - * that a terminal cannot be accessed multiple times (only one connection - * to a terminal is allowed). In that particular case, the pending path is - * severed. If it is the first connection, the pending path is accepted and - * associated to the struct hvc_iucv_private. The iucv state is updated to - * reflect that a communication path has been established. + * The function uses the @ipuser data to determine if the pending path belongs + * to a terminal managed by this device driver. + * If the path belongs to this driver, ensure that the terminal is not accessed + * multiple times (only one connection to a terminal is allowed). + * If the terminal is not yet connected, the pending path is accepted and is + * associated to the appropriate struct hvc_iucv_private instance. * - * Returns 0 if the path belongs to a terminal managed by the this HVC backend; + * Returns 0 if @path belongs to a terminal managed by the this device driver; * otherwise returns -ENODEV in order to dispatch this path to other handlers. * * Locking: struct hvc_iucv_private->lock @@ -672,7 +647,6 @@ static int hvc_iucv_path_pending(struct iucv_path *path, priv = hvc_iucv_table[i]; break; } - if (!priv) return -ENODEV; @@ -719,8 +693,7 @@ out_path_handled: * sets the iucv state to IUCV_SEVERED for the associated struct * hvc_iucv_private instance. Later, the IUCV_SEVERED state triggers a tty * hangup (hvc_iucv_get_chars() / hvc_iucv_write()). - * - * If tty portion of the HVC is closed then clean up the outqueue in addition. + * If tty portion of the HVC is closed, clean up the outqueue. * * Locking: struct hvc_iucv_private->lock */ @@ -755,9 +728,9 @@ static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16]) * @path: Pending path (struct iucv_path) * @msg: Pointer to the IUCV message * - * The function stores an incoming message on the input queue for later + * The function puts an incoming message on the input queue for later * processing (by hvc_iucv_get_chars() / hvc_iucv_write()). - * However, if the tty has not yet been opened, the message is rejected. + * If the tty has not yet been opened, the message is rejected. * * Locking: struct hvc_iucv_private->lock */ @@ -773,6 +746,7 @@ static void hvc_iucv_msg_pending(struct iucv_path *path, return; } + spin_lock(&priv->lock); /* reject messages if tty has not yet been opened */ @@ -791,7 +765,7 @@ static void hvc_iucv_msg_pending(struct iucv_path *path, list_add_tail(&rb->list, &priv->tty_inqueue); - hvc_kick(); /* wake up hvc console thread */ + hvc_kick(); /* wake up hvc thread */ unlock_return: spin_unlock(&priv->lock); @@ -802,10 +776,10 @@ unlock_return: * @path: Pending path (struct iucv_path) * @msg: Pointer to the IUCV message * - * The function is called upon completion of message delivery and the - * message is removed from the outqueue. Additional delivery information - * can be found in msg->audit: rejected messages (0x040000 (IPADRJCT)) and - * purged messages (0x010000 (IPADPGNR)). + * The function is called upon completion of message delivery to remove the + * message from the outqueue. Additional delivery information can be found + * msg->audit: rejected messages (0x040000 (IPADRJCT)), and + * purged messages (0x010000 (IPADPGNR)). * * Locking: struct hvc_iucv_private->lock */ @@ -841,8 +815,8 @@ static struct hv_ops hvc_iucv_ops = { * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance * @id: hvc_iucv_table index * - * This function allocates a new hvc_iucv_private struct and put the - * instance into hvc_iucv_table at index @id. + * This function allocates a new hvc_iucv_private structure and stores + * the instance in hvc_iucv_table at index @id. * Returns 0 on success; otherwise non-zero. */ static int __init hvc_iucv_alloc(int id) @@ -867,7 +841,7 @@ static int __init hvc_iucv_alloc(int id) return -ENOMEM; } - /* Finally allocate hvc */ + /* finally allocate hvc */ priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */ HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256); if (IS_ERR(priv->hvc)) { @@ -877,7 +851,7 @@ static int __init hvc_iucv_alloc(int id) return rc; } - /* kick khvcd thread; instead of using polling */ + /* notify HVC thread instead of using polling */ priv->hvc->irq_requested = 1; /* setup iucv related information */ @@ -890,7 +864,7 @@ static int __init hvc_iucv_alloc(int id) } /** - * hvc_iucv_init() - Initialization of HVC backend for z/VM IUCV + * hvc_iucv_init() - z/VM IUCV HVC device driver initialization */ static int __init hvc_iucv_init(void) { @@ -929,7 +903,7 @@ static int __init hvc_iucv_init(void) rc = hvc_iucv_alloc(i); if (rc) { pr_err("Creating a new HVC terminal device " - "failed with error code=%d\n", rc); + "failed with error code=%d\n", rc); goto out_error_hvc; } } -- cgit v1.2.3 From 68c6b3d2c6e49671f6974c9c5ea31c5f190cc8a5 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Fri, 9 Jan 2009 12:15:00 +0100 Subject: [S390] hvc_iucv: Refactor console and device initialization The console_initcall() order might pick up the hvc_iucv device as preferred console even if it is not yet initialized. Move HVC console instantiation to hvc_iucv_init() and cleanup device driver initialization. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- drivers/char/hvc_iucv.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c index ce1a25f779c..7b627368caa 100644 --- a/drivers/char/hvc_iucv.c +++ b/drivers/char/hvc_iucv.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -898,6 +899,13 @@ static int __init hvc_iucv_init(void) return -ENOMEM; } + /* register the first terminal device as console + * (must be done before allocating hvc terminal devices) */ + rc = hvc_instantiate(HVC_IUCV_MAGIC, 0, &hvc_iucv_ops); + if (rc) + pr_warning("Registering HVC terminal device as " + "Linux console failed\n"); + /* allocate hvc_iucv_private structs */ for (i = 0; i < hvc_iucv_devices; i++) { rc = hvc_iucv_alloc(i); @@ -932,16 +940,6 @@ out_error_hvc: return rc; } -/** - * hvc_iucv_console_init() - Early console initialization - */ -static int __init hvc_iucv_console_init(void) -{ - if (!MACHINE_IS_VM || !hvc_iucv_devices) - return -ENODEV; - return hvc_instantiate(HVC_IUCV_MAGIC, 0, &hvc_iucv_ops); -} - /** * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter * @val: Parameter value (numeric) @@ -952,10 +950,5 @@ static int __init hvc_iucv_config(char *val) } -module_init(hvc_iucv_init); -console_initcall(hvc_iucv_console_init); +device_initcall(hvc_iucv_init); __setup("hvc_iucv=", hvc_iucv_config); - -MODULE_LICENSE("GPL"); -MODULE_DESCRIPTION("HVC back-end for z/VM IUCV."); -MODULE_AUTHOR("Hendrik Brueckner "); -- cgit v1.2.3 From 6c089fd3502c4655ad7dd9b0f83ab9cb98c98ba3 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Fri, 9 Jan 2009 12:15:01 +0100 Subject: [S390] hvc_iucv: Special handling of IUCV HVC devices This patch introduces special handling of the IUCV HVC console device. If the first IUCV HVC terminal is used as (preferred) Linux console, and needs some special handling for hangup. The hvc_iucv_private structure contains a flag to indicate whether a IUCV HVC device is used as a console. A terminal acting as "console" behaves different if a tty hangup occurs: If the iucv communication path is severed, a tty hangup is not triggered (because the HVC layer does not notify its back-end in that case). Instead, the console session is left unchanged and the IUCV HVC device is reset to allow re-connects. Note: Any output between the disconnect and a re-connect is discarded. Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- drivers/char/hvc_iucv.c | 40 ++++++++++++++++++++++++++++------------ 1 file changed, 28 insertions(+), 12 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c index 7b627368caa..a53496828b7 100644 --- a/drivers/char/hvc_iucv.c +++ b/drivers/char/hvc_iucv.c @@ -60,6 +60,7 @@ enum tty_state_t { struct hvc_iucv_private { struct hvc_struct *hvc; /* HVC struct reference */ u8 srv_name[8]; /* IUCV service name (ebcdic) */ + unsigned char is_console; /* Linux console usage flag */ enum iucv_state_t iucv_state; /* IUCV connection status */ enum tty_state_t tty_state; /* TTY status */ struct iucv_path *path; /* IUCV path pointer */ @@ -93,6 +94,7 @@ static unsigned long hvc_iucv_devices = 1; /* Array of allocated hvc iucv tty lines... */ static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; +#define IUCV_HVC_CON_IDX (0) /* Kmem cache and mempool for iucv_tty_buffer elements */ static struct kmem_cache *hvc_iucv_buffer_cache; @@ -139,7 +141,7 @@ static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags) bufp = mempool_alloc(hvc_iucv_mempool, flags); if (!bufp) return NULL; - memset(bufp, 0, sizeof(struct iucv_tty_buffer)); + memset(bufp, 0, sizeof(*bufp)); if (size > 0) { bufp->msg.length = MSG_SIZE(size); @@ -463,7 +465,7 @@ static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count) * @id: Additional data (originally passed to hvc_alloc): the index of an struct * hvc_iucv_private instance. * - * The function sets the tty state to TTY_OPEN for the struct hvc_iucv_private + * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private * instance that is derived from @id. Always returns 0. * * Locking: struct hvc_iucv_private->lock, spin_lock_bh @@ -707,6 +709,9 @@ static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16]) /* If the tty has not yet been opened, clean up the hvc_iucv_private * structure to allow re-connects. + * This is also done for our console device because console hangups + * are handled specially and no notifier is called by HVC. + * The tty session is active (TTY_OPEN) and ready for re-connects... * * If it has been opened, let get_chars() return -EPIPE to signal the * HVC layer to hang up the tty. @@ -716,7 +721,11 @@ static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16]) if (priv->tty_state == TTY_CLOSED) hvc_iucv_cleanup(priv); else - hvc_kick(); + if (priv->is_console) { + hvc_iucv_cleanup(priv); + priv->tty_state = TTY_OPENED; + } else + hvc_kick(); spin_unlock(&priv->lock); /* finally sever path (outside of priv->lock due to lock ordering) */ @@ -747,7 +756,6 @@ static void hvc_iucv_msg_pending(struct iucv_path *path, return; } - spin_lock(&priv->lock); /* reject messages if tty has not yet been opened */ @@ -814,13 +822,14 @@ static struct hv_ops hvc_iucv_ops = { /** * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance - * @id: hvc_iucv_table index + * @id: hvc_iucv_table index + * @is_console: Flag if the instance is used as Linux console * * This function allocates a new hvc_iucv_private structure and stores * the instance in hvc_iucv_table at index @id. * Returns 0 on success; otherwise non-zero. */ -static int __init hvc_iucv_alloc(int id) +static int __init hvc_iucv_alloc(int id, unsigned int is_console) { struct hvc_iucv_private *priv; char name[9]; @@ -842,6 +851,9 @@ static int __init hvc_iucv_alloc(int id) return -ENOMEM; } + /* set console flag */ + priv->is_console = is_console; + /* finally allocate hvc */ priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */ HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256); @@ -869,7 +881,8 @@ static int __init hvc_iucv_alloc(int id) */ static int __init hvc_iucv_init(void) { - int rc, i; + int rc; + unsigned int i; if (!MACHINE_IS_VM) { pr_info("The z/VM IUCV HVC device driver cannot " @@ -901,14 +914,16 @@ static int __init hvc_iucv_init(void) /* register the first terminal device as console * (must be done before allocating hvc terminal devices) */ - rc = hvc_instantiate(HVC_IUCV_MAGIC, 0, &hvc_iucv_ops); - if (rc) - pr_warning("Registering HVC terminal device as " - "Linux console failed\n"); + rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops); + if (rc) { + pr_err("Registering HVC terminal device as " + "Linux console failed\n"); + goto out_error_memory; + } /* allocate hvc_iucv_private structs */ for (i = 0; i < hvc_iucv_devices; i++) { - rc = hvc_iucv_alloc(i); + rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0); if (rc) { pr_err("Creating a new HVC terminal device " "failed with error code=%d\n", rc); @@ -935,6 +950,7 @@ out_error_hvc: hvc_remove(hvc_iucv_table[i]->hvc); kfree(hvc_iucv_table[i]); } +out_error_memory: mempool_destroy(hvc_iucv_mempool); kmem_cache_destroy(hvc_iucv_buffer_cache); return rc; -- cgit v1.2.3