ASYNC_CONN_FLUSH_WORK /* async work flush in progress */
};
+/*
+ * File operations for anonymous inode file associated with a SCIF endpoint,
+ * used in kernel mode SCIF poll. Kernel mode SCIF poll calls portions of the
+ * poll API in the kernel and these take in a struct file *. Since a struct
+ * file is not available to kernel mode SCIF, it uses an anonymous file for
+ * this purpose.
+ */
+const struct file_operations scif_anon_fops = {
+ .owner = THIS_MODULE,
+};
+
scif_epd_t scif_open(void)
{
struct scif_endpt *ep;
+ int err;
might_sleep();
ep = kzalloc(sizeof(*ep), GFP_KERNEL);
if (!ep->qp_info.qp)
goto err_qp_alloc;
+ err = scif_anon_inode_getfile(ep);
+ if (err)
+ goto err_anon_inode;
+
spin_lock_init(&ep->lock);
mutex_init(&ep->sendlock);
mutex_init(&ep->recvlock);
"SCIFAPI open: ep %p success\n", ep);
return ep;
+err_anon_inode:
+ kfree(ep->qp_info.qp);
err_qp_alloc:
kfree(ep);
err_ep_alloc:
}
}
scif_put_port(ep->port.port);
+ scif_anon_inode_fput(ep);
scif_teardown_ep(ep);
scif_add_epd_to_zombie_list(ep, !SCIF_EPLOCK_HELD);
return 0;
list_del(&ep->conn_list);
}
spin_unlock(&scif_info.nb_connect_lock);
- if (ep)
+ if (ep) {
ep->conn_err = scif_conn_func(ep);
+ wake_up_interruptible(&ep->conn_pend_wq);
+ }
} while (ep);
}
ep->remote_dev = &scif_dev[dst->node];
ep->qp_info.qp->magic = SCIFEP_MAGIC;
if (ep->conn_async_state == ASYNC_CONN_INPROGRESS) {
+ init_waitqueue_head(&ep->conn_pend_wq);
spin_lock(&scif_info.nb_connect_lock);
list_add_tail(&ep->conn_list, &scif_info.nb_connect_list);
spin_unlock(&scif_info.nb_connect_lock);
goto scif_accept_error_qpalloc;
}
+ err = scif_anon_inode_getfile(cep);
+ if (err)
+ goto scif_accept_error_anon_inode;
+
cep->qp_info.qp->magic = SCIFEP_MAGIC;
spdev = scif_get_peer_dev(cep->remote_dev);
if (IS_ERR(spdev)) {
spin_unlock(&cep->lock);
return 0;
scif_accept_error_map:
+ scif_anon_inode_fput(cep);
+scif_accept_error_anon_inode:
scif_teardown_ep(cep);
scif_accept_error_qpalloc:
kfree(cep);
}
EXPORT_SYMBOL_GPL(scif_recv);
+static inline void _scif_poll_wait(struct file *f, wait_queue_head_t *wq,
+ poll_table *p, struct scif_endpt *ep)
+{
+ /*
+ * Because poll_wait makes a GFP_KERNEL allocation, give up the lock
+ * and regrab it afterwards. Because the endpoint state might have
+ * changed while the lock was given up, the state must be checked
+ * again after re-acquiring the lock. The code in __scif_pollfd(..)
+ * does this.
+ */
+ spin_unlock(&ep->lock);
+ poll_wait(f, wq, p);
+ spin_lock(&ep->lock);
+}
+
+unsigned int
+__scif_pollfd(struct file *f, poll_table *wait, struct scif_endpt *ep)
+{
+ unsigned int mask = 0;
+
+ dev_dbg(scif_info.mdev.this_device,
+ "SCIFAPI pollfd: ep %p %s\n", ep, scif_ep_states[ep->state]);
+
+ spin_lock(&ep->lock);
+
+ /* Endpoint is waiting for a non-blocking connect to complete */
+ if (ep->conn_async_state == ASYNC_CONN_INPROGRESS) {
+ _scif_poll_wait(f, &ep->conn_pend_wq, wait, ep);
+ if (ep->conn_async_state == ASYNC_CONN_INPROGRESS) {
+ if (ep->state == SCIFEP_CONNECTED ||
+ ep->state == SCIFEP_DISCONNECTED ||
+ ep->conn_err)
+ mask |= POLLOUT;
+ goto exit;
+ }
+ }
+
+ /* Endpoint is listening for incoming connection requests */
+ if (ep->state == SCIFEP_LISTENING) {
+ _scif_poll_wait(f, &ep->conwq, wait, ep);
+ if (ep->state == SCIFEP_LISTENING) {
+ if (ep->conreqcnt)
+ mask |= POLLIN;
+ goto exit;
+ }
+ }
+
+ /* Endpoint is connected or disconnected */
+ if (ep->state == SCIFEP_CONNECTED || ep->state == SCIFEP_DISCONNECTED) {
+ if (poll_requested_events(wait) & POLLIN)
+ _scif_poll_wait(f, &ep->recvwq, wait, ep);
+ if (poll_requested_events(wait) & POLLOUT)
+ _scif_poll_wait(f, &ep->sendwq, wait, ep);
+ if (ep->state == SCIFEP_CONNECTED ||
+ ep->state == SCIFEP_DISCONNECTED) {
+ /* Data can be read without blocking */
+ if (scif_rb_count(&ep->qp_info.qp->inbound_q, 1))
+ mask |= POLLIN;
+ /* Data can be written without blocking */
+ if (scif_rb_space(&ep->qp_info.qp->outbound_q))
+ mask |= POLLOUT;
+ /* Return POLLHUP if endpoint is disconnected */
+ if (ep->state == SCIFEP_DISCONNECTED)
+ mask |= POLLHUP;
+ goto exit;
+ }
+ }
+
+ /* Return POLLERR if the endpoint is in none of the above states */
+ mask |= POLLERR;
+exit:
+ spin_unlock(&ep->lock);
+ return mask;
+}
+
+/**
+ * scif_poll() - Kernel mode SCIF poll
+ * @ufds: Array of scif_pollepd structures containing the end points
+ * and events to poll on
+ * @nfds: Size of the ufds array
+ * @timeout_msecs: Timeout in msecs, -ve implies infinite timeout
+ *
+ * The code flow in this function is based on do_poll(..) in select.c
+ *
+ * Returns the number of endpoints which have pending events or 0 in
+ * the event of a timeout. If a signal is used for wake up, -EINTR is
+ * returned.
+ */
+int
+scif_poll(struct scif_pollepd *ufds, unsigned int nfds, long timeout_msecs)
+{
+ struct poll_wqueues table;
+ poll_table *pt;
+ int i, mask, count = 0, timed_out = timeout_msecs == 0;
+ u64 timeout = timeout_msecs < 0 ? MAX_SCHEDULE_TIMEOUT
+ : msecs_to_jiffies(timeout_msecs);
+
+ poll_initwait(&table);
+ pt = &table.pt;
+ while (1) {
+ for (i = 0; i < nfds; i++) {
+ pt->_key = ufds[i].events | POLLERR | POLLHUP;
+ mask = __scif_pollfd(ufds[i].epd->anon,
+ pt, ufds[i].epd);
+ mask &= ufds[i].events | POLLERR | POLLHUP;
+ if (mask) {
+ count++;
+ pt->_qproc = NULL;
+ }
+ ufds[i].revents = mask;
+ }
+ pt->_qproc = NULL;
+ if (!count) {
+ count = table.error;
+ if (signal_pending(current))
+ count = -EINTR;
+ }
+ if (count || timed_out)
+ break;
+
+ if (!schedule_timeout_interruptible(timeout))
+ timed_out = 1;
+ }
+ poll_freewait(&table);
+ return count;
+}
+EXPORT_SYMBOL_GPL(scif_poll);
+
int scif_get_node_ids(u16 *nodes, int len, u16 *self)
{
int online = 0;
* @conn_port: Connection port
* @conn_err: Errors during connection
* @conn_async_state: Async connection
+ * @conn_pend_wq: Used by poll while waiting for incoming connections
* @conn_list: List of async connection requests
+ * @anon: anonymous file for use in kernel mode scif poll
*/
struct scif_endpt {
enum scif_epd_state state;
struct scif_port_id conn_port;
int conn_err;
int conn_async_state;
+ wait_queue_head_t conn_pend_wq;
struct list_head conn_list;
+ struct file *anon;
};
static inline int scifdev_alive(struct scif_endpt *ep)
return _scifdev_alive(ep->remote_dev);
}
+static inline int scif_anon_inode_getfile(scif_epd_t epd)
+{
+ epd->anon = anon_inode_getfile("scif", &scif_anon_fops, NULL, 0);
+ if (IS_ERR(epd->anon))
+ return PTR_ERR(epd->anon);
+ return 0;
+}
+
+static inline void scif_anon_inode_fput(scif_epd_t epd)
+{
+ if (epd->anon) {
+ fput(epd->anon);
+ epd->anon = NULL;
+ }
+}
+
void scif_cleanup_zombie_epd(void);
void scif_teardown_ep(void *endpt);
void scif_cleanup_ep_qp(struct scif_endpt *ep);
void scif_clientrcvd(struct scif_dev *scifdev, struct scifmsg *msg);
int __scif_connect(scif_epd_t epd, struct scif_port_id *dst, bool non_block);
int __scif_flush(scif_epd_t epd);
+unsigned int __scif_pollfd(struct file *f, poll_table *wait,
+ struct scif_endpt *ep);
#endif /* SCIF_EPD_H */
typedef struct scif_endpt *scif_epd_t;
+/**
+ * struct scif_pollepd - SCIF endpoint to be monitored via scif_poll
+ * @epd: SCIF endpoint
+ * @events: requested events
+ * @revents: returned events
+ */
+struct scif_pollepd {
+ scif_epd_t epd;
+ short events;
+ short revents;
+};
+
#define SCIF_OPEN_FAILED ((scif_epd_t)-1)
#define SCIF_REGISTER_FAILED ((off_t)-1)
#define SCIF_MMAP_FAILED ((void *)-1)
*/
int scif_get_node_ids(u16 *nodes, int len, u16 *self);
+/**
+ * scif_poll() - Wait for some event on an endpoint
+ * @epds: Array of endpoint descriptors
+ * @nepds: Length of epds
+ * @timeout: Upper limit on time for which scif_poll() will block
+ *
+ * scif_poll() waits for one of a set of endpoints to become ready to perform
+ * an I/O operation.
+ *
+ * The epds argument specifies the endpoint descriptors to be examined and the
+ * events of interest for each endpoint descriptor. epds is a pointer to an
+ * array with one member for each open endpoint descriptor of interest.
+ *
+ * The number of items in the epds array is specified in nepds. The epd field
+ * of scif_pollepd is an endpoint descriptor of an open endpoint. The field
+ * events is a bitmask specifying the events which the application is
+ * interested in. The field revents is an output parameter, filled by the
+ * kernel with the events that actually occurred. The bits returned in revents
+ * can include any of those specified in events, or one of the values POLLERR,
+ * POLLHUP, or POLLNVAL. (These three bits are meaningless in the events
+ * field, and will be set in the revents field whenever the corresponding
+ * condition is true.)
+ *
+ * If none of the events requested (and no error) has occurred for any of the
+ * endpoint descriptors, then scif_poll() blocks until one of the events occurs.
+ *
+ * The timeout argument specifies an upper limit on the time for which
+ * scif_poll() will block, in milliseconds. Specifying a negative value in
+ * timeout means an infinite timeout.
+ *
+ * The following bits may be set in events and returned in revents.
+ * POLLIN - Data may be received without blocking. For a connected
+ * endpoint, this means that scif_recv() may be called without blocking. For a
+ * listening endpoint, this means that scif_accept() may be called without
+ * blocking.
+ * POLLOUT - Data may be sent without blocking. For a connected endpoint, this
+ * means that scif_send() may be called without blocking. POLLOUT may also be
+ * used to block waiting for a non-blocking connect to complete. This bit value
+ * has no meaning for a listening endpoint and is ignored if specified.
+ *
+ * The following bits are only returned in revents, and are ignored if set in
+ * events.
+ * POLLERR - An error occurred on the endpoint
+ * POLLHUP - The connection to the peer endpoint was disconnected
+ * POLLNVAL - The specified endpoint descriptor is invalid.
+ *
+ * Return:
+ * Upon successful completion, scif_poll() returns a non-negative value. A
+ * positive value indicates the total number of endpoint descriptors that have
+ * been selected (that is, endpoint descriptors for which the revents member is
+ * non-zero). A value of 0 indicates that the call timed out and no endpoint
+ * descriptors have been selected. Otherwise in user mode -1 is returned and
+ * errno is set to indicate the error; in kernel mode the negative of one of
+ * the following errors is returned.
+ *
+ * Errors:
+ * EINTR - A signal occurred before any requested event
+ * EINVAL - The nepds argument is greater than {OPEN_MAX}
+ * ENOMEM - There was no space to allocate file descriptor tables
+ */
+int scif_poll(struct scif_pollepd *epds, unsigned int nepds, long timeout);
+
#endif /* __SCIF_H__ */
projects / platform / kernel / linux-rpi.git / commitdiff