GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-07-06 22:42:10 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

misc: mic: SCIF poll

Browse source 
SCIF poll allows both user and kernel mode clients to wait on
events on a SCIF endpoint. These events include availability of
space or data in the SCIF ring buffer, availability of connection
requests on a listening endpoint and completion of connections
when using async connects.

Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ashutosh Dixit 2015-09-29 18:10:44 -07:00 • committed by Greg Kroah-Hartman
parent ff39988abd
commit b7f944411b
5 changed files with 264 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

74
include/linux/scif.h
View file

@ -93,6 +93,18 @@ enum {
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)
@ -990,4 +1002,66 @@ int scif_fence_signal(scif_epd_t epd, off_t loff, u64 lval, off_t roff,
*/
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__ */