diff options
Diffstat (limited to 'drivers/char/hvc_iucv.c')
| -rw-r--r-- | drivers/char/hvc_iucv.c | 850 |
1 files changed, 850 insertions, 0 deletions
diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c new file mode 100644 index 00000000000..5ea7d7713fc --- /dev/null +++ b/drivers/char/hvc_iucv.c @@ -0,0 +1,850 @@ +/* + * hvc_iucv.c - z/VM IUCV back-end for the Hypervisor Console (HVC) + * + * This back-end for HVC provides terminal access via + * z/VM IUCV communication paths. + * + * Copyright IBM Corp. 2008. + * + * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> + */ +#define KMSG_COMPONENT "hvc_iucv" + +#include <linux/types.h> +#include <asm/ebcdic.h> +#include <linux/mempool.h> +#include <linux/module.h> +#include <linux/tty.h> +#include <net/iucv/iucv.h> + +#include "hvc_console.h" + + +/* HVC backend for z/VM IUCV */ +#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) + +/* IUCV TTY message */ +#define MSG_VERSION 0x02 /* Message version */ +#define MSG_TYPE_ERROR 0x01 /* Error message */ +#define MSG_TYPE_TERMENV 0x02 /* Terminal environment variable */ +#define MSG_TYPE_TERMIOS 0x04 /* Terminal IO struct update */ +#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 */ +#define MSG_MAX_DATALEN (~(u16)0) + u16 datalen; /* Payload length */ + u8 data[]; /* Payload buffer */ +} __attribute__((packed)); + +enum iucv_state_t { + IUCV_DISCONN = 0, + IUCV_CONNECTED = 1, + IUCV_SEVERED = 2, +}; + +enum tty_state_t { + TTY_CLOSED = 0, + TTY_OPENED = 1, +}; + +struct hvc_iucv_private { + struct hvc_struct *hvc; /* HVC console 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 */ + struct iucv_path *path; /* IUCV path pointer */ + spinlock_t lock; /* hvc_iucv_private lock */ + struct list_head tty_outqueue; /* outgoing IUCV messages */ + struct list_head tty_inqueue; /* incoming IUCV messages */ +}; + +struct iucv_tty_buffer { + struct list_head list; /* list pointer */ + struct iucv_message msg; /* store an incoming IUCV message */ + size_t offset; /* data buffer offset */ + struct iucv_tty_msg *mbuf; /* buffer to store input/output data */ +}; + +/* IUCV callback handler */ +static int hvc_iucv_path_pending(struct iucv_path *, u8[8], u8[16]); +static void hvc_iucv_path_severed(struct iucv_path *, u8[16]); +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; + +/* Array of allocated hvc iucv tty lines... */ +static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; + +/* Kmem cache and mempool for iucv_tty_buffer elements */ +static struct kmem_cache *hvc_iucv_buffer_cache; +static mempool_t *hvc_iucv_mempool; + +/* IUCV handler callback functions */ +static struct iucv_handler hvc_iucv_handler = { + .path_pending = hvc_iucv_path_pending, + .path_severed = hvc_iucv_path_severed, + .message_complete = hvc_iucv_msg_complete, + .message_pending = hvc_iucv_msg_pending, +}; + + +/** + * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance. + * @num: The HVC virtual terminal number (vtermno) + * + * This function returns the struct hvc_iucv_private instance that corresponds + * to the HVC virtual terminal number specified as parameter @num. + */ +struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) +{ + if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices)) + return NULL; + return hvc_iucv_table[num - HVC_IUCV_MAGIC]; +} + +/** + * alloc_tty_buffer() - Returns a new struct iucv_tty_buffer element. + * @size: Size of the internal buffer used to store data. + * @flags: Memory allocation flags passed to mempool. + * + * This function allocates a new struct iucv_tty_buffer element and, optionally, + * 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) +{ + struct iucv_tty_buffer *bufp; + + bufp = mempool_alloc(hvc_iucv_mempool, flags); + if (!bufp) + return NULL; + memset(bufp, 0, sizeof(struct iucv_tty_buffer)); + + if (size > 0) { + bufp->msg.length = MSG_SIZE(size); + bufp->mbuf = kmalloc(bufp->msg.length, flags); + if (!bufp->mbuf) { + mempool_free(bufp, hvc_iucv_mempool); + return NULL; + } + bufp->mbuf->version = MSG_VERSION; + bufp->mbuf->type = MSG_TYPE_DATA; + bufp->mbuf->datalen = (u16) size; + } + return bufp; +} + +/** + * 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) +{ + kfree(bufp->mbuf); + mempool_free(bufp, hvc_iucv_mempool); +} + +/** + * 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. + */ +static void destroy_tty_buffer_list(struct list_head *list) +{ + struct iucv_tty_buffer *ent, *next; + + list_for_each_entry_safe(ent, next, list, list) { + list_del(&ent->list); + destroy_tty_buffer(ent); + } +} + +/** + * 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. + * @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 + * 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 + * 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). + */ +static int hvc_iucv_write(struct hvc_iucv_private *priv, + char *buf, int count, int *has_more_data) +{ + struct iucv_tty_buffer *rb; + int written; + int rc; + + /* 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 (priv->iucv_state == IUCV_SEVERED) + return -EPIPE; + + /* check if there are pending messages */ + if (list_empty(&priv->tty_inqueue)) + return 0; + + /* receive a iucv message and flip data to the tty (ldisc) */ + rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list); + + written = 0; + if (!rb->mbuf) { /* message not yet received ... */ + /* allocate mem to store msg data; if no memory is available + * then leave the buffer on the list and re-try later */ + rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC); + if (!rb->mbuf) + return -ENOMEM; + + rc = __iucv_message_receive(priv->path, &rb->msg, 0, + rb->mbuf, rb->msg.length, NULL); + switch (rc) { + case 0: /* Successful */ + break; + case 2: /* No message found */ + case 9: /* Message purged */ + break; + default: + written = -EIO; + } + /* remove buffer if an error has occured or received data + * is not correct */ + if (rc || (rb->mbuf->version != MSG_VERSION) || + (rb->msg.length != MSG_SIZE(rb->mbuf->datalen))) + goto out_remove_buffer; + } + + switch (rb->mbuf->type) { + case MSG_TYPE_DATA: + written = min_t(int, rb->mbuf->datalen - rb->offset, count); + memcpy(buf, rb->mbuf->data + rb->offset, written); + if (written < (rb->mbuf->datalen - rb->offset)) { + rb->offset += written; + *has_more_data = 1; + goto out_written; + } + break; + + case MSG_TYPE_WINSIZE: + if (rb->mbuf->datalen != sizeof(struct winsize)) + break; + hvc_resize(priv->hvc, *((struct winsize *)rb->mbuf->data)); + break; + + case MSG_TYPE_ERROR: /* ignored ... */ + case MSG_TYPE_TERMENV: /* ignored ... */ + case MSG_TYPE_TERMIOS: /* ignored ... */ + break; + } + +out_remove_buffer: + list_del(&rb->list); + destroy_tty_buffer(rb); + *has_more_data = !list_empty(&priv->tty_inqueue); + +out_written: + return written; +} + +/** + * hvc_iucv_get_chars() - HVC get_chars operation. + * @vtermno: HVC virtual terminal number. + * @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. + * + * Locking: The routine gets called under an irqsave() spinlock; and + * the routine locks the struct hvc_iucv_private->lock to call + * helper functions. + */ +static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) +{ + struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); + int written; + int has_more_data; + + if (count <= 0) + return 0; + + if (!priv) + return -ENODEV; + + spin_lock(&priv->lock); + has_more_data = 0; + written = hvc_iucv_write(priv, buf, count, &has_more_data); + spin_unlock(&priv->lock); + + /* if there are still messages on the queue... schedule another run */ + if (has_more_data) + hvc_kick(); + + return written; +} + +/** + * hvc_iucv_send() - Send an IUCV message containing terminal data. + * @priv: Pointer to struct hvc_iucv_private instance. + * @buf: Buffer containing data to send. + * @size: 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. + * + * 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 (can be passed to HVC layer to cause a tty hangup). + */ +static int hvc_iucv_send(struct hvc_iucv_private *priv, const char *buf, + int count) +{ + struct iucv_tty_buffer *sb; + int rc; + u16 len; + + if (priv->iucv_state == IUCV_SEVERED) + return -EPIPE; + + if (priv->iucv_state == IUCV_DISCONN) + return 0; + + len = min_t(u16, MSG_MAX_DATALEN, count); + + /* allocate internal buffer to store msg data and also compute total + * message length */ + sb = alloc_tty_buffer(len, GFP_ATOMIC); + if (!sb) + return -ENOMEM; + + sb->mbuf->datalen = len; + memcpy(sb->mbuf->data, buf, len); + + 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) { + list_del(&sb->list); + destroy_tty_buffer(sb); + len = 0; + } + + return len; +} + +/** + * hvc_iucv_put_chars() - HVC put_chars operation. + * @vtermno: HVC virtual terminal number. + * @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. + * + * Locking: The method gets called under an irqsave() spinlock; and + * locks struct hvc_iucv_private->lock. + */ +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; + + if (count <= 0) + return 0; + + if (!priv) + return -ENODEV; + + spin_lock(&priv->lock); + sent = hvc_iucv_send(priv, buf, count); + spin_unlock(&priv->lock); + + return sent; +} + +/** + * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time. + * @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. + * + * The function sets the tty state to TTY_OPEN for the struct hvc_iucv_private + * instance that is derived from @id. Always returns 0. + * + * Locking: struct hvc_iucv_private->lock, spin_lock_bh + */ +static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id) +{ + struct hvc_iucv_private *priv; + + priv = hvc_iucv_get_private(id); + if (!priv) + return 0; + + spin_lock_bh(&priv->lock); + priv->tty_state = TTY_OPENED; + spin_unlock_bh(&priv->lock); + + return 0; +} + +/** + * hvc_iucv_cleanup() - Clean up function if the tty portion is finally closed. + * @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) +{ + destroy_tty_buffer_list(&priv->tty_outqueue); + destroy_tty_buffer_list(&priv->tty_inqueue); + + priv->tty_state = TTY_CLOSED; + priv->iucv_state = IUCV_DISCONN; +} + +/** + * 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, + * virtual or otherwise) has occured. + * + * The HVC backend for z/VM IUCV 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. + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) +{ + struct hvc_iucv_private *priv; + + priv = hvc_iucv_get_private(id); + if (!priv) + return; + + 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. + * + * 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 + * client if we disconnect on hang up) */ + priv->tty_state = TTY_CLOSED; + + if (priv->iucv_state == IUCV_SEVERED) + hvc_iucv_cleanup(priv); + spin_unlock_bh(&priv->lock); +} + +/** + * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time. + * @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 the last tty device file + * descriptor has been closed. + * The function calls hvc_iucv_cleanup() to clean up the struct hvc_iucv_private + * instance. + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) +{ + struct hvc_iucv_private *priv; + struct iucv_path *path; + + priv = hvc_iucv_get_private(id); + if (!priv) + return; + + spin_lock_bh(&priv->lock); + path = priv->path; /* save reference to IUCV path */ + priv->path = NULL; + hvc_iucv_cleanup(priv); + spin_unlock_bh(&priv->lock); + + /* sever IUCV path outside of priv->lock due to lock ordering of: + * priv->lock <--> iucv_table_lock */ + if (path) { + iucv_path_sever(path, NULL); + iucv_path_free(path); + } +} + +/** + * hvc_iucv_path_pending() - IUCV handler to process a connection request. + * @path: Pending path (struct iucv_path) + * @ipvmid: Originator z/VM system identifier + * @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. + * + * Returns 0 if the path belongs to a terminal managed by the this HVC backend; + * otherwise returns -ENODEV in order to dispatch this path to other handlers. + * + * Locking: struct hvc_iucv_private->lock + */ +static int hvc_iucv_path_pending(struct iucv_path *path, + u8 ipvmid[8], u8 ipuser[16]) +{ + struct hvc_iucv_private *priv; + u8 nuser_data[16]; + int i, rc; + + priv = NULL; + for (i = 0; i < hvc_iucv_devices; i++) + if (hvc_iucv_table[i] && + (0 == memcmp(hvc_iucv_table[i]->srv_name, ipuser, 8))) { + priv = hvc_iucv_table[i]; + break; + } + + if (!priv) + return -ENODEV; + + spin_lock(&priv->lock); + + /* If the terminal is already connected or being severed, then sever + * this path to enforce that there is only ONE established communication + * path per terminal. */ + if (priv->iucv_state != IUCV_DISCONN) { + iucv_path_sever(path, ipuser); + iucv_path_free(path); + goto out_path_handled; + } + + /* accept path */ + memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */ + memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */ + path->msglim = 0xffff; /* IUCV MSGLIMIT */ + path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */ + rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv); + if (rc) { + iucv_path_sever(path, ipuser); + iucv_path_free(path); + goto out_path_handled; + } + priv->path = path; + priv->iucv_state = IUCV_CONNECTED; + +out_path_handled: + spin_unlock(&priv->lock); + return 0; +} + +/** + * hvc_iucv_path_severed() - IUCV handler to process a path sever. + * @path: Pending path (struct iucv_path) + * @ipuser: User specified data for this path + * (AF_IUCV: port/service name and originator port) + * + * The function also severs the path (as required by the IUCV protocol) and + * 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. + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16]) +{ + struct hvc_iucv_private *priv = path->private; + + 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 been opened, the get_chars() callback returns + * -EPIPE to signal the hvc console layer to hang up the tty. */ + priv->path = NULL; + if (priv->tty_state == TTY_CLOSED) + hvc_iucv_cleanup(priv); + spin_unlock(&priv->lock); + + /* finally sever path (outside of priv->lock due to lock ordering) */ + iucv_path_sever(path, ipuser); + iucv_path_free(path); +} + +/** + * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message. + * @path: Pending path (struct iucv_path) + * @msg: Pointer to the IUCV message + * + * The function stores 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. + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_msg_pending(struct iucv_path *path, + struct iucv_message *msg) +{ + struct hvc_iucv_private *priv = path->private; + struct iucv_tty_buffer *rb; + + spin_lock(&priv->lock); + + /* reject messages if tty has not yet been opened */ + if (priv->tty_state == TTY_CLOSED) { + iucv_message_reject(path, msg); + goto unlock_return; + } + + /* allocate buffer an empty buffer element */ + rb = alloc_tty_buffer(0, GFP_ATOMIC); + if (!rb) { + iucv_message_reject(path, msg); + goto unlock_return; /* -ENOMEM */ + } + rb->msg = *msg; + + list_add_tail(&rb->list, &priv->tty_inqueue); + + hvc_kick(); /* wakup hvc console thread */ + +unlock_return: + spin_unlock(&priv->lock); +} + +/** + * hvc_iucv_msg_complete() - IUCV handler to process message completion + * @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)). + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_msg_complete(struct iucv_path *path, + struct iucv_message *msg) +{ + struct hvc_iucv_private *priv = path->private; + struct iucv_tty_buffer *ent, *next; + LIST_HEAD(list_remove); + + spin_lock(&priv->lock); + list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list) + if (ent->msg.id == msg->id) { + list_move(&ent->list, &list_remove); + break; + } + spin_unlock(&priv->lock); + destroy_tty_buffer_list(&list_remove); +} + + +/* HVC operations */ +static struct hv_ops hvc_iucv_ops = { + .get_chars = hvc_iucv_get_chars, + .put_chars = hvc_iucv_put_chars, + .notifier_add = hvc_iucv_notifier_add, + .notifier_del = hvc_iucv_notifier_del, + .notifier_hangup = hvc_iucv_notifier_hangup, +}; + +/** + * 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. + * Returns 0 on success; otherwise non-zero. + */ +static int __init hvc_iucv_alloc(int id) +{ + struct hvc_iucv_private *priv; + char name[9]; + int rc; + + priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + spin_lock_init(&priv->lock); + INIT_LIST_HEAD(&priv->tty_outqueue); + INIT_LIST_HEAD(&priv->tty_inqueue); + + /* Finally allocate hvc */ + priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, + HVC_IUCV_MAGIC + id, &hvc_iucv_ops, PAGE_SIZE); + if (IS_ERR(priv->hvc)) { + rc = PTR_ERR(priv->hvc); + kfree(priv); + return rc; + } + + /* setup iucv related information */ + snprintf(name, 9, "ihvc%-4d", id); + memcpy(priv->srv_name, name, 8); + ASCEBC(priv->srv_name, 8); + + hvc_iucv_table[id] = priv; + return 0; +} + +/** + * hvc_iucv_init() - Initialization of HVC backend for z/VM IUCV + */ +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"); + return -ENODEV; + } + + if (!hvc_iucv_devices) + return -ENODEV; + + if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) + return -EINVAL; + + hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT, + 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); + 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); + kmem_cache_destroy(hvc_iucv_buffer_cache); + return -ENOMEM; + } + + /* allocate hvc_iucv_private structs */ + 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); + goto out_error_hvc; + } + } + + /* register IUCV callback handler */ + rc = iucv_register(&hvc_iucv_handler, 0); + if (rc) { + pr_err("Could not register iucv handler (rc=%d).\n", rc); + goto out_error_iucv; + } + + return 0; + +out_error_iucv: + iucv_unregister(&hvc_iucv_handler, 0); +out_error_hvc: + for (i = 0; i < hvc_iucv_devices; i++) + if (hvc_iucv_table[i]) { + if (hvc_iucv_table[i]->hvc) + hvc_remove(hvc_iucv_table[i]->hvc); + kfree(hvc_iucv_table[i]); + } + mempool_destroy(hvc_iucv_mempool); + kmem_cache_destroy(hvc_iucv_buffer_cache); + 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) + */ +static int __init hvc_iucv_config(char *val) +{ + return strict_strtoul(val, 10, &hvc_iucv_devices); +} + + +module_init(hvc_iucv_init); +console_initcall(hvc_iucv_console_init); +__setup("hvc_iucv=", hvc_iucv_config); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("HVC back-end for z/VM IUCV."); +MODULE_AUTHOR("Hendrik Brueckner <brueckner@linux.vnet.ibm.com>"); |