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Diffstat (limited to 'include/linux/scif.h')
| -rw-r--r-- | include/linux/scif.h | 993 |
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diff --git a/include/linux/scif.h b/include/linux/scif.h new file mode 100644 index 000000000000..44f4f3898bbe --- /dev/null +++ b/include/linux/scif.h @@ -0,0 +1,993 @@ +/* + * Intel MIC Platform Software Stack (MPSS) + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2014 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * BSD LICENSE + * + * Copyright(c) 2014 Intel Corporation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Intel SCIF driver. + * + */ +#ifndef __SCIF_H__ +#define __SCIF_H__ + +#include <linux/types.h> +#include <linux/poll.h> +#include <linux/scif_ioctl.h> + +#define SCIF_ACCEPT_SYNC 1 +#define SCIF_SEND_BLOCK 1 +#define SCIF_RECV_BLOCK 1 + +enum { + SCIF_PROT_READ = (1 << 0), + SCIF_PROT_WRITE = (1 << 1) +}; + +enum { + SCIF_MAP_FIXED = 0x10, + SCIF_MAP_KERNEL = 0x20, +}; + +enum { + SCIF_FENCE_INIT_SELF = (1 << 0), + SCIF_FENCE_INIT_PEER = (1 << 1), + SCIF_SIGNAL_LOCAL = (1 << 4), + SCIF_SIGNAL_REMOTE = (1 << 5) +}; + +enum { + SCIF_RMA_USECPU = (1 << 0), + SCIF_RMA_USECACHE = (1 << 1), + SCIF_RMA_SYNC = (1 << 2), + SCIF_RMA_ORDERED = (1 << 3) +}; + +/* End of SCIF Admin Reserved Ports */ +#define SCIF_ADMIN_PORT_END 1024 + +/* End of SCIF Reserved Ports */ +#define SCIF_PORT_RSVD 1088 + +typedef struct scif_endpt *scif_epd_t; + +#define SCIF_OPEN_FAILED ((scif_epd_t)-1) +#define SCIF_REGISTER_FAILED ((off_t)-1) +#define SCIF_MMAP_FAILED ((void *)-1) + +/** + * scif_open() - Create an endpoint + * + * Return: + * Upon successful completion, scif_open() returns an endpoint descriptor to + * be used in subsequent SCIF functions calls to refer to that endpoint; + * otherwise in user mode SCIF_OPEN_FAILED (that is ((scif_epd_t)-1)) is + * returned and errno is set to indicate the error; in kernel mode a NULL + * scif_epd_t is returned. + * + * Errors: + * ENOMEM - Insufficient kernel memory was available + */ +scif_epd_t scif_open(void); + +/** + * scif_bind() - Bind an endpoint to a port + * @epd: endpoint descriptor + * @pn: port number + * + * scif_bind() binds endpoint epd to port pn, where pn is a port number on the + * local node. If pn is zero, a port number greater than or equal to + * SCIF_PORT_RSVD is assigned and returned. Each endpoint may be bound to + * exactly one local port. Ports less than 1024 when requested can only be bound + * by system (or root) processes or by processes executed by privileged users. + * + * Return: + * Upon successful completion, scif_bind() returns the port number to which epd + * is bound; 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: + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * EINVAL - the endpoint or the port is already bound + * EISCONN - The endpoint is already connected + * ENOSPC - No port number available for assignment + * EACCES - The port requested is protected and the user is not the superuser + */ +int scif_bind(scif_epd_t epd, u16 pn); + +/** + * scif_listen() - Listen for connections on an endpoint + * @epd: endpoint descriptor + * @backlog: maximum pending connection requests + * + * scif_listen() marks the endpoint epd as a listening endpoint - that is, as + * an endpoint that will be used to accept incoming connection requests. Once + * so marked, the endpoint is said to be in the listening state and may not be + * used as the endpoint of a connection. + * + * The endpoint, epd, must have been bound to a port. + * + * The backlog argument defines the maximum length to which the queue of + * pending connections for epd may grow. If a connection request arrives when + * the queue is full, the client may receive an error with an indication that + * the connection was refused. + * + * Return: + * Upon successful completion, scif_listen() returns 0; 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: + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * EINVAL - the endpoint is not bound to a port + * EISCONN - The endpoint is already connected or listening + */ +int scif_listen(scif_epd_t epd, int backlog); + +/** + * scif_connect() - Initiate a connection on a port + * @epd: endpoint descriptor + * @dst: global id of port to which to connect + * + * The scif_connect() function requests the connection of endpoint epd to remote + * port dst. If the connection is successful, a peer endpoint, bound to dst, is + * created on node dst.node. On successful return, the connection is complete. + * + * If the endpoint epd has not already been bound to a port, scif_connect() + * will bind it to an unused local port. + * + * A connection is terminated when an endpoint of the connection is closed, + * either explicitly by scif_close(), or when a process that owns one of the + * endpoints of the connection is terminated. + * + * In user space, scif_connect() supports an asynchronous connection mode + * if the application has set the O_NONBLOCK flag on the endpoint via the + * fcntl() system call. Setting this flag will result in the calling process + * not to wait during scif_connect(). + * + * Return: + * Upon successful completion, scif_connect() returns the port ID to which the + * endpoint, epd, is bound; 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: + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNREFUSED - The destination was not listening for connections or refused + * the connection request + * EINVAL - dst.port is not a valid port ID + * EISCONN - The endpoint is already connected + * ENOMEM - No buffer space is available + * ENODEV - The destination node does not exist, or the node is lost or existed, + * but is not currently in the network since it may have crashed + * ENOSPC - No port number available for assignment + * EOPNOTSUPP - The endpoint is listening and cannot be connected + */ +int scif_connect(scif_epd_t epd, struct scif_port_id *dst); + +/** + * scif_accept() - Accept a connection on an endpoint + * @epd: endpoint descriptor + * @peer: global id of port to which connected + * @newepd: new connected endpoint descriptor + * @flags: flags + * + * The scif_accept() call extracts the first connection request from the queue + * of pending connections for the port on which epd is listening. scif_accept() + * creates a new endpoint, bound to the same port as epd, and allocates a new + * SCIF endpoint descriptor, returned in newepd, for the endpoint. The new + * endpoint is connected to the endpoint through which the connection was + * requested. epd is unaffected by this call, and remains in the listening + * state. + * + * On successful return, peer holds the global port identifier (node id and + * local port number) of the port which requested the connection. + * + * A connection is terminated when an endpoint of the connection is closed, + * either explicitly by scif_close(), or when a process that owns one of the + * endpoints of the connection is terminated. + * + * The number of connections that can (subsequently) be accepted on epd is only + * limited by system resources (memory). + * + * The flags argument is formed by OR'ing together zero or more of the + * following values. + * SCIF_ACCEPT_SYNC - block until a connection request is presented. If + * SCIF_ACCEPT_SYNC is not in flags, and no pending + * connections are present on the queue, scif_accept() + * fails with an EAGAIN error + * + * In user mode, the select() and poll() functions can be used to determine + * when there is a connection request. In kernel mode, the scif_poll() + * function may be used for this purpose. A readable event will be delivered + * when a connection is requested. + * + * Return: + * Upon successful completion, scif_accept() returns 0; 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: + * EAGAIN - SCIF_ACCEPT_SYNC is not set and no connections are present to be + * accepted or SCIF_ACCEPT_SYNC is not set and remote node failed to complete + * its connection request + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * EINTR - Interrupted function + * EINVAL - epd is not a listening endpoint, or flags is invalid, or peer is + * NULL, or newepd is NULL + * ENODEV - The requesting node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOMEM - Not enough space + * ENOENT - Secondary part of epd registration failed + */ +int scif_accept(scif_epd_t epd, struct scif_port_id *peer, scif_epd_t + *newepd, int flags); + +/** + * scif_close() - Close an endpoint + * @epd: endpoint descriptor + * + * scif_close() closes an endpoint and performs necessary teardown of + * facilities associated with that endpoint. + * + * If epd is a listening endpoint then it will no longer accept connection + * requests on the port to which it is bound. Any pending connection requests + * are rejected. + * + * If epd is a connected endpoint, then its peer endpoint is also closed. RMAs + * which are in-process through epd or its peer endpoint will complete before + * scif_close() returns. Registered windows of the local and peer endpoints are + * released as if scif_unregister() was called against each window. + * + * Closing a SCIF endpoint does not affect local registered memory mapped by + * a SCIF endpoint on a remote node. The local memory remains mapped by the peer + * SCIF endpoint explicitly removed by calling munmap(..) by the peer. + * + * If the peer endpoint's receive queue is not empty at the time that epd is + * closed, then the peer endpoint can be passed as the endpoint parameter to + * scif_recv() until the receive queue is empty. + * + * epd is freed and may no longer be accessed. + * + * Return: + * Upon successful completion, scif_close() returns 0; 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: + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + */ +int scif_close(scif_epd_t epd); + +/** + * scif_send() - Send a message + * @epd: endpoint descriptor + * @msg: message buffer address + * @len: message length + * @flags: blocking mode flags + * + * scif_send() sends data to the peer of endpoint epd. Up to len bytes of data + * are copied from memory starting at address msg. On successful execution the + * return value of scif_send() is the number of bytes that were sent, and is + * zero if no bytes were sent because len was zero. scif_send() may be called + * only when the endpoint is in a connected state. + * + * If a scif_send() call is non-blocking, then it sends only those bytes which + * can be sent without waiting, up to a maximum of len bytes. + * + * If a scif_send() call is blocking, then it normally returns after sending + * all len bytes. If a blocking call is interrupted or the connection is + * reset, the call is considered successful if some bytes were sent or len is + * zero, otherwise the call is considered unsuccessful. + * + * In user mode, the select() and poll() functions can be used to determine + * when the send queue is not full. In kernel mode, the scif_poll() function + * may be used for this purpose. + * + * It is recommended that scif_send()/scif_recv() only be used for short + * control-type message communication between SCIF endpoints. The SCIF RMA + * APIs are expected to provide better performance for transfer sizes of + * 1024 bytes or longer for the current MIC hardware and software + * implementation. + * + * scif_send() will block until the entire message is sent if SCIF_SEND_BLOCK + * is passed as the flags argument. + * + * Return: + * Upon successful completion, scif_send() returns the number of bytes sent; + * 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: + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * EFAULT - An invalid address was specified for a parameter + * EINVAL - flags is invalid, or len is negative + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOMEM - Not enough space + * ENOTCONN - The endpoint is not connected + */ +int scif_send(scif_epd_t epd, void *msg, int len, int flags); + +/** + * scif_recv() - Receive a message + * @epd: endpoint descriptor + * @msg: message buffer address + * @len: message buffer length + * @flags: blocking mode flags + * + * scif_recv() receives data from the peer of endpoint epd. Up to len bytes of + * data are copied to memory starting at address msg. On successful execution + * the return value of scif_recv() is the number of bytes that were received, + * and is zero if no bytes were received because len was zero. scif_recv() may + * be called only when the endpoint is in a connected state. + * + * If a scif_recv() call is non-blocking, then it receives only those bytes + * which can be received without waiting, up to a maximum of len bytes. + * + * If a scif_recv() call is blocking, then it normally returns after receiving + * all len bytes. If the blocking call was interrupted due to a disconnection, + * subsequent calls to scif_recv() will copy all bytes received upto the point + * of disconnection. + * + * In user mode, the select() and poll() functions can be used to determine + * when data is available to be received. In kernel mode, the scif_poll() + * function may be used for this purpose. + * + * It is recommended that scif_send()/scif_recv() only be used for short + * control-type message communication between SCIF endpoints. The SCIF RMA + * APIs are expected to provide better performance for transfer sizes of + * 1024 bytes or longer for the current MIC hardware and software + * implementation. + * + * scif_recv() will block until the entire message is received if + * SCIF_RECV_BLOCK is passed as the flags argument. + * + * Return: + * Upon successful completion, scif_recv() returns the number of bytes + * received; 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: + * EAGAIN - The destination node is returning from a low power state + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * EFAULT - An invalid address was specified for a parameter + * EINVAL - flags is invalid, or len is negative + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOMEM - Not enough space + * ENOTCONN - The endpoint is not connected + */ +int scif_recv(scif_epd_t epd, void *msg, int len, int flags); + +/** + * scif_register() - Mark a memory region for remote access. + * @epd: endpoint descriptor + * @addr: starting virtual address + * @len: length of range + * @offset: offset of window + * @prot_flags: read/write protection flags + * @map_flags: mapping flags + * + * The scif_register() function opens a window, a range of whole pages of the + * registered address space of the endpoint epd, starting at offset po and + * continuing for len bytes. The value of po, further described below, is a + * function of the parameters offset and len, and the value of map_flags. Each + * page of the window represents the physical memory page which backs the + * corresponding page of the range of virtual address pages starting at addr + * and continuing for len bytes. addr and len are constrained to be multiples + * of the page size. A successful scif_register() call returns po. + * + * When SCIF_MAP_FIXED is set in the map_flags argument, po will be offset + * exactly, and offset is constrained to be a multiple of the page size. The + * mapping established by scif_register() will not replace any existing + * registration; an error is returned if any page within the range [offset, + * offset + len - 1] intersects an existing window. + * + * When SCIF_MAP_FIXED is not set, the implementation uses offset in an + * implementation-defined manner to arrive at po. The po value so chosen will + * be an area of the registered address space that the implementation deems + * suitable for a mapping of len bytes. An offset value of 0 is interpreted as + * granting the implementation complete freedom in selecting po, subject to + * constraints described below. A non-zero value of offset is taken to be a + * suggestion of an offset near which the mapping should be placed. When the + * implementation selects a value for po, it does not replace any extant + * window. In all cases, po will be a multiple of the page size. + * + * The physical pages which are so represented by a window are available for + * access in calls to mmap(), scif_readfrom(), scif_writeto(), + * scif_vreadfrom(), and scif_vwriteto(). While a window is registered, the + * physical pages represented by the window will not be reused by the memory + * subsystem for any other purpose. Note that the same physical page may be + * represented by multiple windows. + * + * Subsequent operations which change the memory pages to which virtual + * addresses are mapped (such as mmap(), munmap()) have no effect on + * existing window. + * + * If the process will fork(), it is recommended that the registered + * virtual address range be marked with MADV_DONTFORK. Doing so will prevent + * problems due to copy-on-write semantics. + * + * The prot_flags argument is formed by OR'ing together one or more of the + * following values. + * SCIF_PROT_READ - allow read operations from the window + * SCIF_PROT_WRITE - allow write operations to the window + * + * The map_flags argument can be set to SCIF_MAP_FIXED which interprets a + * fixed offset. + * + * Return: + * Upon successful completion, scif_register() returns the offset at which the + * mapping was placed (po); otherwise in user mode SCIF_REGISTER_FAILED (that + * is (off_t *)-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: + * EADDRINUSE - SCIF_MAP_FIXED is set in map_flags, and pages in the range + * [offset, offset + len -1] are already registered + * EAGAIN - The mapping could not be performed due to lack of resources + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * EFAULT - Addresses in the range [addr, addr + len - 1] are invalid + * EINVAL - map_flags is invalid, or prot_flags is invalid, or SCIF_MAP_FIXED is + * set in flags, and offset is not a multiple of the page size, or addr is not a + * multiple of the page size, or len is not a multiple of the page size, or is + * 0, or offset is negative + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOMEM - Not enough space + * ENOTCONN -The endpoint is not connected + */ +off_t scif_register(scif_epd_t epd, void *addr, size_t len, off_t offset, + int prot_flags, int map_flags); + +/** + * scif_unregister() - Mark a memory region for remote access. + * @epd: endpoint descriptor + * @offset: start of range to unregister + * @len: length of range to unregister + * + * The scif_unregister() function closes those previously registered windows + * which are entirely within the range [offset, offset + len - 1]. It is an + * error to specify a range which intersects only a subrange of a window. + * + * On a successful return, pages within the window may no longer be specified + * in calls to mmap(), scif_readfrom(), scif_writeto(), scif_vreadfrom(), + * scif_vwriteto(), scif_get_pages, and scif_fence_signal(). The window, + * however, continues to exist until all previous references against it are + * removed. A window is referenced if there is a mapping to it created by + * mmap(), or if scif_get_pages() was called against the window + * (and the pages have not been returned via scif_put_pages()). A window is + * also referenced while an RMA, in which some range of the window is a source + * or destination, is in progress. Finally a window is referenced while some + * offset in that window was specified to scif_fence_signal(), and the RMAs + * marked by that call to scif_fence_signal() have not completed. While a + * window is in this state, its registered address space pages are not + * available for use in a new registered window. + * + * When all such references to the window have been removed, its references to + * all the physical pages which it represents are removed. Similarly, the + * registered address space pages of the window become available for + * registration in a new window. + * + * Return: + * Upon successful completion, scif_unregister() returns 0; 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. In the event of an + * error, no windows are unregistered. + * + * Errors: + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * EINVAL - the range [offset, offset + len - 1] intersects a subrange of a + * window, or offset is negative + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOTCONN - The endpoint is not connected + * ENXIO - Offsets in the range [offset, offset + len - 1] are invalid for the + * registered address space of epd + */ +int scif_unregister(scif_epd_t epd, off_t offset, size_t len); + +/** + * scif_readfrom() - Copy from a remote address space + * @epd: endpoint descriptor + * @loffset: offset in local registered address space to + * which to copy + * @len: length of range to copy + * @roffset: offset in remote registered address space + * from which to copy + * @rma_flags: transfer mode flags + * + * scif_readfrom() copies len bytes from the remote registered address space of + * the peer of endpoint epd, starting at the offset roffset to the local + * registered address space of epd, starting at the offset loffset. + * + * Each of the specified ranges [loffset, loffset + len - 1] and [roffset, + * roffset + len - 1] must be within some registered window or windows of the + * local and remote nodes. A range may intersect multiple registered windows, + * but only if those windows are contiguous in the registered address space. + * + * If rma_flags includes SCIF_RMA_USECPU, then the data is copied using + * programmed read/writes. Otherwise the data is copied using DMA. If rma_- + * flags includes SCIF_RMA_SYNC, then scif_readfrom() will return after the + * transfer is complete. Otherwise, the transfer may be performed asynchron- + * ously. The order in which any two asynchronous RMA operations complete + * is non-deterministic. The synchronization functions, scif_fence_mark()/ + * scif_fence_wait() and scif_fence_signal(), can be used to synchronize to + * the completion of asynchronous RMA operations on the same endpoint. + * + * The DMA transfer of individual bytes is not guaranteed to complete in + * address order. If rma_flags includes SCIF_RMA_ORDERED, then the last + * cacheline or partial cacheline of the source range will become visible on + * the destination node after all other transferred data in the source + * range has become visible on the destination node. + * + * The optimal DMA performance will likely be realized if both + * loffset and roffset are cacheline aligned (are a multiple of 64). Lower + * performance will likely be realized if loffset and roffset are not + * cacheline aligned but are separated by some multiple of 64. The lowest level + * of performance is likely if loffset and roffset are not separated by a + * multiple of 64. + * + * The rma_flags argument is formed by ORing together zero or more of the + * following values. + * SCIF_RMA_USECPU - perform the transfer using the CPU, otherwise use the DMA + * engine. + * SCIF_RMA_SYNC - perform the transfer synchronously, returning after the + * transfer has completed. Passing this flag results in the + * current implementation busy waiting and consuming CPU cycles + * while the DMA transfer is in progress for best performance by + * avoiding the interrupt latency. + * SCIF_RMA_ORDERED - ensure that the last cacheline or partial cacheline of + * the source range becomes visible on the destination node + * after all other transferred data in the source range has + * become visible on the destination + * + * Return: + * Upon successful completion, scif_readfrom() returns 0; 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: + * EACCESS - Attempt to write to a read-only range + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * EINVAL - rma_flags is invalid + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOTCONN - The endpoint is not connected + * ENXIO - The range [loffset, loffset + len - 1] is invalid for the registered + * address space of epd, or, The range [roffset, roffset + len - 1] is invalid + * for the registered address space of the peer of epd, or loffset or roffset + * is negative + */ +int scif_readfrom(scif_epd_t epd, off_t loffset, size_t len, off_t + roffset, int rma_flags); + +/** + * scif_writeto() - Copy to a remote address space + * @epd: endpoint descriptor + * @loffset: offset in local registered address space + * from which to copy + * @len: length of range to copy + * @roffset: offset in remote registered address space to + * which to copy + * @rma_flags: transfer mode flags + * + * scif_writeto() copies len bytes from the local registered address space of + * epd, starting at the offset loffset to the remote registered address space + * of the peer of endpoint epd, starting at the offset roffset. + * + * Each of the specified ranges [loffset, loffset + len - 1] and [roffset, + * roffset + len - 1] must be within some registered window or windows of the + * local and remote nodes. A range may intersect multiple registered windows, + * but only if those windows are contiguous in the registered address space. + * + * If rma_flags includes SCIF_RMA_USECPU, then the data is copied using + * programmed read/writes. Otherwise the data is copied using DMA. If rma_- + * flags includes SCIF_RMA_SYNC, then scif_writeto() will return after the + * transfer is complete. Otherwise, the transfer may be performed asynchron- + * ously. The order in which any two asynchronous RMA operations complete + * is non-deterministic. The synchronization functions, scif_fence_mark()/ + * scif_fence_wait() and scif_fence_signal(), can be used to synchronize to + * the completion of asynchronous RMA operations on the same endpoint. + * + * The DMA transfer of individual bytes is not guaranteed to complete in + * address order. If rma_flags includes SCIF_RMA_ORDERED, then the last + * cacheline or partial cacheline of the source range will become visible on + * the destination node after all other transferred data in the source + * range has become visible on the destination node. + * + * The optimal DMA performance will likely be realized if both + * loffset and roffset are cacheline aligned (are a multiple of 64). Lower + * performance will likely be realized if loffset and roffset are not cacheline + * aligned but are separated by some multiple of 64. The lowest level of + * performance is likely if loffset and roffset are not separated by a multiple + * of 64. + * + * The rma_flags argument is formed by ORing together zero or more of the + * following values. + * SCIF_RMA_USECPU - perform the transfer using the CPU, otherwise use the DMA + * engine. + * SCIF_RMA_SYNC - perform the transfer synchronously, returning after the + * transfer has completed. Passing this flag results in the + * current implementation busy waiting and consuming CPU cycles + * while the DMA transfer is in progress for best performance by + * avoiding the interrupt latency. + * SCIF_RMA_ORDERED - ensure that the last cacheline or partial cacheline of + * the source range becomes visible on the destination node + * after all other transferred data in the source range has + * become visible on the destination + * + * Return: + * Upon successful completion, scif_readfrom() returns 0; 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: + * EACCESS - Attempt to write to a read-only range + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * EINVAL - rma_flags is invalid + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOTCONN - The endpoint is not connected + * ENXIO - The range [loffset, loffset + len - 1] is invalid for the registered + * address space of epd, or, The range [roffset , roffset + len -1] is invalid + * for the registered address space of the peer of epd, or loffset or roffset + * is negative + */ +int scif_writeto(scif_epd_t epd, off_t loffset, size_t len, off_t + roffset, int rma_flags); + +/** + * scif_vreadfrom() - Copy from a remote address space + * @epd: endpoint descriptor + * @addr: address to which to copy + * @len: length of range to copy + * @roffset: offset in remote registered address space + * from which to copy + * @rma_flags: transfer mode flags + * + * scif_vreadfrom() copies len bytes from the remote registered address + * space of the peer of endpoint epd, starting at the offset roffset, to local + * memory, starting at addr. + * + * The specified range [roffset, roffset + len - 1] must be within some + * registered window or windows of the remote nodes. The range may + * intersect multiple registered windows, but only if those windows are + * contiguous in the registered address space. + * + * If rma_flags includes SCIF_RMA_USECPU, then the data is copied using + * programmed read/writes. Otherwise the data is copied using DMA. If rma_- + * flags includes SCIF_RMA_SYNC, then scif_vreadfrom() will return after the + * transfer is complete. Otherwise, the transfer may be performed asynchron- + * ously. The order in which any two asynchronous RMA operations complete + * is non-deterministic. The synchronization functions, scif_fence_mark()/ + * scif_fence_wait() and scif_fence_signal(), can be used to synchronize to + * the completion of asynchronous RMA operations on the same endpoint. + * + * The DMA transfer of individual bytes is not guaranteed to complete in + * address order. If rma_flags includes SCIF_RMA_ORDERED, then the last + * cacheline or partial cacheline of the source range will become visible on + * the destination node after all other transferred data in the source + * range has become visible on the destination node. + * + * If rma_flags includes SCIF_RMA_USECACHE, then the physical pages which back + * the specified local memory range may be remain in a pinned state even after + * the specified transfer completes. This may reduce overhead if some or all of + * the same virtual address range is referenced in a subsequent call of + * scif_vreadfrom() or scif_vwriteto(). + * + * The optimal DMA performance will likely be realized if both + * addr and roffset are cacheline aligned (are a multiple of 64). Lower + * performance will likely be realized if addr and roffset are not + * cacheline aligned but are separated by some multiple of 64. The lowest level + * of performance is likely if addr and roffset are not separated by a + * multiple of 64. + * + * The rma_flags argument is formed by ORing together zero or more of the + * following values. + * SCIF_RMA_USECPU - perform the transfer using the CPU, otherwise use the DMA + * engine. + * SCIF_RMA_USECACHE - enable registration caching + * SCIF_RMA_SYNC - perform the transfer synchronously, returning after the + * transfer has completed. Passing this flag results in the + * current implementation busy waiting and consuming CPU cycles + * while the DMA transfer is in progress for best performance by + * avoiding the interrupt latency. + * SCIF_RMA_ORDERED - ensure that the last cacheline or partial cacheline of + * the source range becomes visible on the destination node + * after all other transferred data in the source range has + * become visible on the destination + * + * Return: + * Upon successful completion, scif_vreadfrom() returns 0; 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: + * EACCESS - Attempt to write to a read-only range + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * EFAULT - Addresses in the range [addr, addr + len - 1] are invalid + * EINVAL - rma_flags is invalid + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOTCONN - The endpoint is not connected + * ENXIO - Offsets in the range [roffset, roffset + len - 1] are invalid for the + * registered address space of epd + */ +int scif_vreadfrom(scif_epd_t epd, void *addr, size_t len, off_t roffset, + int rma_flags); + +/** + * scif_vwriteto() - Copy to a remote address space + * @epd: endpoint descriptor + * @addr: address from which to copy + * @len: length of range to copy + * @roffset: offset in remote registered address space to + * which to copy + * @rma_flags: transfer mode flags + * + * scif_vwriteto() copies len bytes from the local memory, starting at addr, to + * the remote registered address space of the peer of endpoint epd, starting at + * the offset roffset. + * + * The specified range [roffset, roffset + len - 1] must be within some + * registered window or windows of the remote nodes. The range may intersect + * multiple registered windows, but only if those windows are contiguous in the + * registered address space. + * + * If rma_flags includes SCIF_RMA_USECPU, then the data is copied using + * programmed read/writes. Otherwise the data is copied using DMA. If rma_- + * flags includes SCIF_RMA_SYNC, then scif_vwriteto() will return after the + * transfer is complete. Otherwise, the transfer may be performed asynchron- + * ously. The order in which any two asynchronous RMA operations complete + * is non-deterministic. The synchronization functions, scif_fence_mark()/ + * scif_fence_wait() and scif_fence_signal(), can be used to synchronize to + * the completion of asynchronous RMA operations on the same endpoint. + * + * The DMA transfer of individual bytes is not guaranteed to complete in + * address order. If rma_flags includes SCIF_RMA_ORDERED, then the last + * cacheline or partial cacheline of the source range will become visible on + * the destination node after all other transferred data in the source + * range has become visible on the destination node. + * + * If rma_flags includes SCIF_RMA_USECACHE, then the physical pages which back + * the specified local memory range may be remain in a pinned state even after + * the specified transfer completes. This may reduce overhead if some or all of + * the same virtual address range is referenced in a subsequent call of + * scif_vreadfrom() or scif_vwriteto(). + * + * The optimal DMA performance will likely be realized if both + * addr and offset are cacheline aligned (are a multiple of 64). Lower + * performance will likely be realized if addr and offset are not cacheline + * aligned but are separated by some multiple of 64. The lowest level of + * performance is likely if addr and offset are not separated by a multiple of + * 64. + * + * The rma_flags argument is formed by ORing together zero or more of the + * following values. + * SCIF_RMA_USECPU - perform the transfer using the CPU, otherwise use the DMA + * engine. + * SCIF_RMA_USECACHE - allow registration caching + * SCIF_RMA_SYNC - perform the transfer synchronously, returning after the + * transfer has completed. Passing this flag results in the + * current implementation busy waiting and consuming CPU cycles + * while the DMA transfer is in progress for best performance by + * avoiding the interrupt latency. + * SCIF_RMA_ORDERED - ensure that the last cacheline or partial cacheline of + * the source range becomes visible on the destination node + * after all other transferred data in the source range has + * become visible on the destination + * + * Return: + * Upon successful completion, scif_vwriteto() returns 0; 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: + * EACCESS - Attempt to write to a read-only range + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * EFAULT - Addresses in the range [addr, addr + len - 1] are invalid + * EINVAL - rma_flags is invalid + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOTCONN - The endpoint is not connected + * ENXIO - Offsets in the range [roffset, roffset + len - 1] are invalid for the + * registered address space of epd + */ +int scif_vwriteto(scif_epd_t epd, void *addr, size_t len, off_t roffset, + int rma_flags); + +/** + * scif_fence_mark() - Mark previously issued RMAs + * @epd: endpoint descriptor + * @flags: control flags + * @mark: marked value returned as output. + * + * scif_fence_mark() returns after marking the current set of all uncompleted + * RMAs initiated through the endpoint epd or the current set of all + * uncompleted RMAs initiated through the peer of endpoint epd. The RMAs are + * marked with a value returned at mark. The application may subsequently call + * scif_fence_wait(), passing the value returned at mark, to await completion + * of all RMAs so marked. + * + * The flags argument has exactly one of the following values. + * SCIF_FENCE_INIT_SELF - RMA operations initiated through endpoint + * epd are marked + * SCIF_FENCE_INIT_PEER - RMA operations initiated through the peer + * of endpoint epd are marked + * + * Return: + * Upon successful completion, scif_fence_mark() returns 0; 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: + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * EINVAL - flags is invalid + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOTCONN - The endpoint is not connected + * ENOMEM - Insufficient kernel memory was available + */ +int scif_fence_mark(scif_epd_t epd, int flags, int *mark); + +/** + * scif_fence_wait() - Wait for completion of marked RMAs + * @epd: endpoint descriptor + * @mark: mark request + * + * scif_fence_wait() returns after all RMAs marked with mark have completed. + * The value passed in mark must have been obtained in a previous call to + * scif_fence_mark(). + * + * Return: + * Upon successful completion, scif_fence_wait() returns 0; 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: + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOTCONN - The endpoint is not connected + * ENOMEM - Insufficient kernel memory was available + */ +int scif_fence_wait(scif_epd_t epd, int mark); + +/** + * scif_fence_signal() - Request a memory update on completion of RMAs + * @epd: endpoint descriptor + * @loff: local offset + * @lval: local value to write to loffset + * @roff: remote offset + * @rval: remote value to write to roffset + * @flags: flags + * + * scif_fence_signal() returns after marking the current set of all uncompleted + * RMAs initiated through the endpoint epd or marking the current set of all + * uncompleted RMAs initiated through the peer of endpoint epd. + * + * If flags includes SCIF_SIGNAL_LOCAL, then on completion of the RMAs in the + * marked set, lval is written to memory at the address corresponding to offset + * loff in the local registered address space of epd. loff must be within a + * registered window. If flags includes SCIF_SIGNAL_REMOTE, then on completion + * of the RMAs in the marked set, rval is written to memory at the address + * corresponding to offset roff in the remote registered address space of epd. + * roff must be within a remote registered window of the peer of epd. Note + * that any specified offset must be DWORD (4 byte / 32 bit) aligned. + * + * The flags argument is formed by OR'ing together the following. + * Exactly one of the following values. + * SCIF_FENCE_INIT_SELF - RMA operations initiated through endpoint + * epd are marked + * SCIF_FENCE_INIT_PEER - RMA operations initiated through the peer + * of endpoint epd are marked + * One or more of the following values. + * SCIF_SIGNAL_LOCAL - On completion of the marked set of RMAs, write lval to + * memory at the address corresponding to offset loff in the local + * registered address space of epd. + * SCIF_SIGNAL_REMOTE - On completion of the marked set of RMAs, write rval to + * memory at the address corresponding to offset roff in the remote + * registered address space of epd. + * + * Return: + * Upon successful completion, scif_fence_signal() returns 0; 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: + * EBADF, ENOTTY - epd is not a valid endpoint descriptor + * ECONNRESET - Connection reset by peer + * EINVAL - flags is invalid, or loff or roff are not DWORD aligned + * ENODEV - The remote node is lost or existed, but is not currently in the + * network since it may have crashed + * ENOTCONN - The endpoint is not connected + * ENXIO - loff is invalid for the registered address of epd, or roff is invalid + * for the registered address space, of the peer of epd + */ +int scif_fence_signal(scif_epd_t epd, off_t loff, u64 lval, off_t roff, + u64 rval, int flags); + +/** + * scif_get_node_ids() - Return information about online nodes + * @nodes: array in which to return online node IDs + * @len: number of entries in the nodes array + * @self: address to place the node ID of the local node + * + * scif_get_node_ids() fills in the nodes array with up to len node IDs of the + * nodes in the SCIF network. If there is not enough space in nodes, as + * indicated by the len parameter, only len node IDs are returned in nodes. The + * return value of scif_get_node_ids() is the total number of nodes currently in + * the SCIF network. By checking the return value against the len parameter, + * the user may determine if enough space for nodes was allocated. + * + * The node ID of the local node is returned at self. + * + * Return: + * Upon successful completion, scif_get_node_ids() returns the actual number of + * online nodes in the SCIF network including 'self'; otherwise in user mode + * -1 is returned and errno is set to indicate the error; in kernel mode no + * errors are returned. + * + * Errors: + * EFAULT - Bad address + */ +int scif_get_node_ids(u16 *nodes, int len, u16 *self); + +#endif /* __SCIF_H__ */ |