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26 /**
27  * @file
28  *
29  * Byte Transfer Layer (BTL)
30  *
31  *
32  * BTL Initialization:
33  *
34  * During library initialization, all available BTL components are
35  * loaded and opened via their mca_base_open_component_fn_t
36  * function. The BTL open function should register any mca parameters
37  * used to tune/adjust the behaviour of the BTL (mca_base_var_register()
38  * mca_base_component_var_register()). Note that the open function may fail
39  * if the resources (e.g. shared libraries, etc) required by the network
40  * transport are not available.
41  *
42  * The mca_btl_base_component_init_fn_t() is then called for each of the
43  * components that are succesfully opened. The component init function may
44  * return either:
45  *
46  * (1) a NULL list of BTL modules if the transport is not available,
47  * (2) a list containing a one or more single BTL modules, where the BTL provides
48  *     a layer of abstraction over one or more physical devices (e.g. NICs),
49  *
50  * During module initialization, the module should post any addressing
51  * information required by its peers. An example would be the TCP
52  * listen port opened by the TCP module for incoming connection
53  * requests. This information is published to peers via the
54  * modex_send() interface. Note that peer information is not
55  * guaranteed to be available via modex_recv() during the
56  * module's init function. However, it will be available during
57  * BTL selection (mca_btl_base_add_proc_fn_t()).
58  *
59  * BTL Selection:
60  *
61  * The upper layer builds an ordered list of the available BTL modules sorted
62  * by their exclusivity ranking. This is a relative ranking that is used
63  * to determine the set of BTLs that may be used to reach a given destination.
64  * During startup the BTL modules are queried via their
65  * mca_btl_base_add_proc_fn_t() to determine if they are able to reach
66  * a given destination.  The BTL module with the highest ranking that
67  * returns success is selected. Subsequent BTL modules are selected only
68  * if they have the same exclusivity ranking.
69  *
70  * An example of how this might be used:
71  *
72  * BTL         Exclusivity   Comments
73  * --------    -----------   ------------------
74  * LO              100       Selected exclusively for local process
75  * SM               50       Selected exclusively for other processes on host
76  * IB                0       Selected based on network reachability
77  * IB                0       Selected based on network reachability
78  * TCP               0       Selected based on network reachability
79  * TCP               0       Selected based on network reachability
80  *
81  * When mca_btl_base_add_proc_fn_t() is called on a  BTL module, the BTL
82  * will populate an OUT variable with mca_btl_base_endpoint_t pointers.
83  * Each pointer is treated as an opaque handle by the upper layer and is
84  * returned to the BTL on subsequent data transfer calls to the
85  * corresponding destination process.  The actual contents of the
86  * data structure are defined on a per BTL basis, and may be used to
87  * cache addressing or connection information, such as a TCP socket
88  * or IB queue pair.
89  *
90  * Progress:
91  *
92  * By default, the library provides for polling based progress of outstanding
93  * requests. The BTL component exports an interface function (btl_progress)
94  * that is called in a polling mode by the PML during calls into the MPI
95  * library. Note that the btl_progress() function is called on the BTL component
96  * rather than each BTL module. This implies that the BTL author is responsible
97  * for iterating over the pending operations in each of the BTL modules associated
98  * with the component.
99  *
100  * On platforms where threading support is provided, the library provides the
101  * option of building with asynchronous threaded progress. In this case, the BTL
102  * author is responsible for providing a thread to progress pending operations.
103  * A thread is associated with the BTL component/module such that transport specific
104  * functionality/APIs may be used to block the thread until a pending operation
105  * completes. This thread MUST NOT poll for completion as this would oversubscribe
106  * the CPU.
107  *
108  * Note that in the threaded case the PML may choose to use a hybrid approach,
109  * such that polling is implemented from the user thread for a fixed number of
110  * cycles before relying on the background thread(s) to complete requests. If
111  * possible the BTL should support the use of both modes concurrently.
112  *
113  */
114 
115 #ifndef OPAL_MCA_BTL_H
116 #define OPAL_MCA_BTL_H
117 
118 #include "opal_config.h"
119 #include "opal/types.h"
120 #include "opal/prefetch.h" /* For OPAL_LIKELY */
121 #include "opal/class/opal_bitmap.h"
122 #include "opal/datatype/opal_convertor.h"
123 #include "opal/mca/mca.h"
124 #include "opal/mca/mpool/mpool.h"
125 #include "opal/mca/rcache/rcache.h"
126 #include "opal/mca/crs/crs.h"
127 #include "opal/mca/crs/base/base.h"
128 
129 BEGIN_C_DECLS
130 
131 /*
132  * BTL types
133  */
134 
135 struct mca_btl_base_module_t;
136 struct mca_btl_base_endpoint_t;
137 struct mca_btl_base_descriptor_t;
138 struct mca_mpool_base_resources_t;
139 struct opal_proc_t;
140 
141 /**
142  * Opaque registration handle for executing RDMA and atomic
143  * operations on a memory region.
144  *
145  * This data inside this handle is appropriate for passing
146  * to remote peers to execute RDMA and atomic operations. The
147  * size needed to send the registration handle can be
148  * obtained from the btl via the btl_registration_handle_size
149  * member. If this size is 0 then no registration data is
150  * needed to execute RDMA or atomic operations.
151  */
152 struct mca_btl_base_registration_handle_t;
153 typedef struct mca_btl_base_registration_handle_t mca_btl_base_registration_handle_t;
154 
155 
156 /* Wildcard endpoint for use in the register_mem function */
157 #define MCA_BTL_ENDPOINT_ANY (struct mca_btl_base_endpoint_t *) -1
158 
159 /* send/recv operations require tag matching */
160 typedef uint8_t mca_btl_base_tag_t;
161 
162 #define MCA_BTL_NO_ORDER       255
163 
164 /*
165  * Communication specific defines. There are a number of active message ID
166  * that can be shred between all frameworks that need to communicate (i.e.
167  * use the PML or the BTL directly). These ID are exchanged between the
168  * processes, therefore they need to be identical everywhere. The simplest
169  * approach is to have them defined as constants, and give each framework a
170  * small number. Here is the rule that defines these ID (they are 8 bits):
171  * - the first 3 bits are used to code the framework (i.e. PML, OSC, COLL)
172  * - the remaining 5 bytes are used internally by the framework, and divided
173  *   based on the components requirements. Therefore, the way the PML and
174  * the OSC frameworks use these defines will be different. For more
175  * information about how these framework ID are defined, take a look in the
176  * header file associated with the framework.
177  */
178 #define MCA_BTL_AM_FRAMEWORK_MASK   0xD0
179 #define MCA_BTL_TAG_BTL             0x20
180 #define MCA_BTL_TAG_PML             0x40
181 #define MCA_BTL_TAG_OSC_RDMA        0x60
182 #define MCA_BTL_TAG_USR             0x80
183 #define MCA_BTL_TAG_MAX             255 /* 1 + highest allowed tag num */
184 
185 /*
186  * Reserved tags for specific BTLs. As multiple BTLs can be active
187  * simultaneously, their tags should not collide.
188  */
189 #define MCA_BTL_TAG_IB                (MCA_BTL_TAG_BTL + 0)
190 #define MCA_BTL_TAG_UDAPL             (MCA_BTL_TAG_BTL + 1)
191 #define MCA_BTL_TAG_SMCUDA            (MCA_BTL_TAG_BTL + 2)
192 #define MCA_BTL_TAG_VADER             (MCA_BTL_TAG_BTL + 3)
193 
194 /* prefered protocol */
195 #define MCA_BTL_FLAGS_SEND            0x0001
196 #define MCA_BTL_FLAGS_PUT             0x0002
197 #define MCA_BTL_FLAGS_GET             0x0004
198 /* btls that set the MCA_BTL_FLAGS_RDMA will always get added to the BML
199  * rdma_btls list. This allows the updated one-sided component to
200  * use btls that are not otherwise used for send/recv. */
201 #define MCA_BTL_FLAGS_RDMA (MCA_BTL_FLAGS_GET|MCA_BTL_FLAGS_PUT)
202 
203 /* btl can send directly from user buffer w/out registration */
204 #define MCA_BTL_FLAGS_SEND_INPLACE    0x0008
205 
206 /* btl transport reliability flags - currently used only by the DR PML */
207 #define MCA_BTL_FLAGS_NEED_ACK        0x0010
208 #define MCA_BTL_FLAGS_NEED_CSUM       0x0020
209 
210 /** deprecated (BTL 3.0) */
211 #define MCA_BTL_FLAGS_RDMA_MATCHED    0x0040
212 
213 /* btl needs local rdma completion */
214 #define MCA_BTL_FLAGS_RDMA_COMPLETION 0x0080
215 
216  /* btl can do heterogeneous rdma operations on byte buffers */
217 #define MCA_BTL_FLAGS_HETEROGENEOUS_RDMA 0x0100
218 
219 /* btl can support failover if enabled */
220 #define MCA_BTL_FLAGS_FAILOVER_SUPPORT 0x0200
221 
222 #define MCA_BTL_FLAGS_CUDA_PUT        0x0400
223 #define MCA_BTL_FLAGS_CUDA_GET        0x0800
224 #define MCA_BTL_FLAGS_CUDA_RDMA (MCA_BTL_FLAGS_CUDA_GET|MCA_BTL_FLAGS_CUDA_PUT)
225 #define MCA_BTL_FLAGS_CUDA_COPY_ASYNC_SEND 0x1000
226 #define MCA_BTL_FLAGS_CUDA_COPY_ASYNC_RECV 0x2000
227 
228 /* btl can support signaled operations. BTLs that support this flag are
229  * expected to provide a mechanism for asynchronous progress on descriptors
230  * where the feature is requested. BTLs should also be aware that users can
231  * (and probably will) turn this flag on and off using the MCA variable
232  * system.
233  */
234 #define MCA_BTL_FLAGS_SIGNALED        0x4000
235 
236 /** The BTL supports network atomic operations */
237 #define MCA_BTL_FLAGS_ATOMIC_OPS      0x08000
238 /** The BTL supports fetching network atomic operations */
239 #define MCA_BTL_FLAGS_ATOMIC_FOPS     0x10000
240 
241 /** The BTL requires add_procs to be with all procs including non-local. Shared-memory
242  * BTLs should not set this flag. */
243 #define MCA_BTL_FLAGS_SINGLE_ADD_PROCS 0x20000
244 
245 /* The BTL is using progress thread and need the protection on matching */
246 #define MCA_BTL_FLAGS_BTL_PROGRESS_THREAD_ENABLED 0x40000
247 
248 /* The BTL supports RMDA flush */
249 #define MCA_BTL_FLAGS_RDMA_FLUSH      0x80000
250 
251 /* Default exclusivity levels */
252 #define MCA_BTL_EXCLUSIVITY_HIGH     (64*1024) /* internal loopback */
253 #define MCA_BTL_EXCLUSIVITY_DEFAULT  1024      /* GM/IB/etc. */
254 #define MCA_BTL_EXCLUSIVITY_LOW      0         /* TCP used as a last resort */
255 
256 /* error callback flags */
257 #define MCA_BTL_ERROR_FLAGS_FATAL 0x1
258 #define MCA_BTL_ERROR_FLAGS_NONFATAL 0x2
259 #define MCA_BTL_ERROR_FLAGS_ADD_CUDA_IPC 0x4
260 
261 /** registration flags. the access flags are a 1-1 mapping with the mpool
262  * access flags. */
263 enum {
264     /** Allow local write on the registered region. If a region is registered
265      * with this flag the registration can be used as the local handle for a
266      * btl_get operation. */
267     MCA_BTL_REG_FLAG_LOCAL_WRITE   = MCA_RCACHE_ACCESS_LOCAL_WRITE,
268     /** Allow remote read on the registered region. If a region is registered
269      * with this flag the registration can be used as the remote handle for a
270      * btl_get operation. */
271     MCA_BTL_REG_FLAG_REMOTE_READ   = MCA_RCACHE_ACCESS_REMOTE_READ,
272     /** Allow remote write on the registered region. If a region is registered
273      * with this flag the registration can be used as the remote handle for a
274      * btl_put operation. */
275     MCA_BTL_REG_FLAG_REMOTE_WRITE  = MCA_RCACHE_ACCESS_REMOTE_WRITE,
276     /** Allow remote atomic operations on the registered region. If a region is
277      * registered with this flag the registration can be used as the remote
278      * handle for a btl_atomic_op or btl_atomic_fop operation. */
279     MCA_BTL_REG_FLAG_REMOTE_ATOMIC = MCA_RCACHE_ACCESS_REMOTE_ATOMIC,
280     /** Allow any btl operation on the registered region. If a region is registered
281      * with this flag the registration can be used as the local or remote handle for
282      * any btl operation. */
283     MCA_BTL_REG_FLAG_ACCESS_ANY    = MCA_RCACHE_ACCESS_ANY,
284 #if OPAL_CUDA_GDR_SUPPORT
285     /** Region is in GPU memory */
286     MCA_BTL_REG_FLAG_CUDA_GPU_MEM  = 0x00010000,
287 #endif
288 };
289 
290 /** supported atomic operations */
291 enum {
292     /** The btl supports atomic add */
293     MCA_BTL_ATOMIC_SUPPORTS_ADD    = 0x00000001,
294     /** The btl supports atomic bitwise and */
295     MCA_BTL_ATOMIC_SUPPORTS_AND    = 0x00000200,
296     /** The btl supports atomic bitwise or */
297     MCA_BTL_ATOMIC_SUPPORTS_OR     = 0x00000400,
298     /** The btl supports atomic bitwise exclusive or */
299     MCA_BTL_ATOMIC_SUPPORTS_XOR    = 0x00000800,
300 
301     /** The btl supports logical and */
302     MCA_BTL_ATOMIC_SUPPORTS_LAND   = 0x00001000,
303     /** The btl supports logical or */
304     MCA_BTL_ATOMIC_SUPPORTS_LOR    = 0x00002000,
305     /** The btl supports logical exclusive or */
306     MCA_BTL_ATOMIC_SUPPORTS_LXOR   = 0x00004000,
307 
308     /** The btl supports atomic swap */
309     MCA_BTL_ATOMIC_SUPPORTS_SWAP   = 0x00010000,
310 
311     /** The btl supports atomic min */
312     MCA_BTL_ATOMIC_SUPPORTS_MIN    = 0x00100000,
313     /** The btl supports atomic min */
314     MCA_BTL_ATOMIC_SUPPORTS_MAX    = 0x00200000,
315 
316     /** The btl supports 32-bit integer operations. Keep in mind the btl may
317      * support only a subset of the available atomics. */
318     MCA_BTL_ATOMIC_SUPPORTS_32BIT  = 0x01000000,
319 
320     /** The btl supports floating-point operations. Keep in mind the btl may
321      * support only a subset of the available atomics and may not support
322      * both 64 or 32-bit floating point. */
323     MCA_BTL_ATOMIC_SUPPORTS_FLOAT  = 0x02000000,
324 
325     /** The btl supports atomic compare-and-swap */
326     MCA_BTL_ATOMIC_SUPPORTS_CSWAP  = 0x10000000,
327 
328     /** The btl guarantees global atomicity (can mix btl atomics with cpu atomics) */
329     MCA_BTL_ATOMIC_SUPPORTS_GLOB   = 0x20000000,
330 };
331 
332 enum {
333     /** Use 32-bit atomics */
334     MCA_BTL_ATOMIC_FLAG_32BIT = 0x00000001,
335     /** Use floating-point atomics */
336     MCA_BTL_ATOMIC_FLAG_FLOAT = 0x00000002,
337 };
338 
339 enum mca_btl_base_atomic_op_t {
340     /** Atomic add: (*remote_address) = (*remote_address) + operand */
341     MCA_BTL_ATOMIC_ADD = 0x0001,
342     /** Atomic and: (*remote_address) = (*remote_address) & operand */
343     MCA_BTL_ATOMIC_AND = 0x0011,
344     /** Atomic or: (*remote_address) = (*remote_address) | operand */
345     MCA_BTL_ATOMIC_OR  = 0x0012,
346     /** Atomic xor: (*remote_address) = (*remote_address) ^ operand */
347     MCA_BTL_ATOMIC_XOR = 0x0014,
348     /** Atomic logical and: (*remote_address) = (*remote_address) && operand */
349     MCA_BTL_ATOMIC_LAND = 0x0015,
350     /** Atomic logical or: (*remote_address) = (*remote_address) || operand */
351     MCA_BTL_ATOMIC_LOR = 0x0016,
352     /** Atomic logical xor: (*remote_address) = (*remote_address) != operand */
353     MCA_BTL_ATOMIC_LXOR = 0x0017,
354     /** Atomic swap: (*remote_address) = operand */
355     MCA_BTL_ATOMIC_SWAP = 0x001a,
356     /** Atomic min */
357     MCA_BTL_ATOMIC_MIN = 0x0020,
358     /** Atomic max */
359     MCA_BTL_ATOMIC_MAX = 0x0021,
360 
361     MCA_BTL_ATOMIC_LAST,
362 };
363 typedef enum mca_btl_base_atomic_op_t mca_btl_base_atomic_op_t;
364 
365 /**
366  * Asynchronous callback function on completion of an operation.
367  * Completion Semantics: The descriptor can be reused or returned to the
368  *  BTL via mca_btl_base_module_free_fn_t. The operation has been queued to
369  *  the network device or will otherwise make asynchronous progress without
370  *  subsequent calls to btl_progress.
371  *
372  * @param[IN] module      the BTL module
373  * @param[IN] endpoint    the BTL endpoint
374  * @param[IN] descriptor  the BTL descriptor
375  *
376  */
377 typedef void (*mca_btl_base_completion_fn_t)(
378     struct mca_btl_base_module_t* module,
379     struct mca_btl_base_endpoint_t* endpoint,
380     struct mca_btl_base_descriptor_t* descriptor,
381     int status);
382 
383 
384 /**
385  * Asynchronous callback function on completion of an rdma or atomic operation.
386  * Completion Semantics: The rdma or atomic memory operation has completed
387  * remotely (i.e.) is remotely visible and the caller is free to deregister
388  * the local_handle or modify the memory in local_address.
389  *
390  * @param[IN] module        the BTL module
391  * @param[IN] endpoint      the BTL endpoint
392  * @param[IN] local_address local address for the operation (if any)
393  * @param[IN] local_handle  local handle associated with the local_address
394  * @param[IN] context       callback context supplied to the rdma/atomic operation
395  * @param[IN] cbdata        callback data supplied to the rdma/atomic operation
396  * @param[IN] status        status of the operation
397  *
398  */
399 typedef void (*mca_btl_base_rdma_completion_fn_t)(
400     struct mca_btl_base_module_t* module,
401     struct mca_btl_base_endpoint_t* endpoint,
402     void *local_address,
403     struct mca_btl_base_registration_handle_t *local_handle,
404     void *context,
405     void *cbdata,
406     int status);
407 
408 
409 /**
410  * Describes a region/segment of memory that is addressable
411  * by an BTL.
412  *
413  * Note: In many cases the alloc and prepare methods of BTLs
414  * do not return a mca_btl_base_segment_t but instead return a
415  * subclass. Extreme care should be used when modifying
416  * BTL segments to prevent overwriting internal BTL data.
417  *
418  * All BTLs MUST use base segments when calling registered
419  * Callbacks.
420  *
421  * BTL MUST use mca_btl_base_segment_t or a subclass and
422  * MUST store their segment length in btl_seg_size. BTLs
423  * MUST specify a segment no larger than MCA_BTL_SEG_MAX_SIZE.
424  */
425 
426 struct mca_btl_base_segment_t {
427     /** Address of the memory */
428     opal_ptr_t seg_addr;
429      /** Length in bytes */
430     uint64_t   seg_len;
431 };
432 typedef struct mca_btl_base_segment_t mca_btl_base_segment_t;
433 
434 
435 #if OPAL_ENABLE_HETEROGENEOUS_SUPPORT && !defined(WORDS_BIGENDIAN)
436 #define MCA_BTL_BASE_SEGMENT_HTON(s)                   \
437         (s).seg_addr.lval = hton64((s).seg_addr.lval); \
438         (s).seg_len = hton64((s).seg_len);
439 #define MCA_BTL_BASE_SEGMENT_NTOH(s)                   \
440         (s).seg_addr.lval = ntoh64((s).seg_addr.lval); \
441         (s).seg_len = ntoh64((s).seg_len);
442 #else
443 #define MCA_BTL_BASE_SEGMENT_HTON(s)
444 #define MCA_BTL_BASE_SEGMENT_NTOH(s)
445 #endif
446 /**
447  * A descriptor that holds the parameters to a send/put/get
448  * operation along w/ a callback routine that is called on
449  * completion of the request.
450  * Note: receive callbacks will store the incomming data segments in
451  *       des_segments
452  */
453 
454 struct mca_btl_base_descriptor_t {
455     opal_free_list_item_t super;
456     mca_btl_base_segment_t *des_segments;     /**< local segments */
457     size_t des_segment_count;                 /**< number of local segments */
458     mca_btl_base_completion_fn_t des_cbfunc;  /**< local callback function */
459     void* des_cbdata;                         /**< opaque callback data */
460     void* des_context;                        /**< more opaque callback data */
461     uint32_t des_flags;                       /**< hints to BTL */
462     /** order value, this is only
463         valid in the local completion callback
464         and may be used in subsequent calls to
465         btl_alloc, btl_prepare_src to request
466         a descriptor that will be ordered w.r.t.
467         this descriptor
468     */
469     uint8_t order;
470 };
471 typedef struct mca_btl_base_descriptor_t mca_btl_base_descriptor_t;
472 
473 OPAL_DECLSPEC OBJ_CLASS_DECLARATION(mca_btl_base_descriptor_t);
474 
475 #define MCA_BTL_DES_FLAGS_PRIORITY          0x0001
476 /* Allow the BTL to dispose the descriptor once the callback
477  * associated was triggered.
478  */
479 #define MCA_BTL_DES_FLAGS_BTL_OWNERSHIP     0x0002
480 /* Allow the BTL to avoid calling the descriptor callback
481  * if the send succeded in the btl_send (i.e in the fast path).
482  */
483 #define MCA_BTL_DES_SEND_ALWAYS_CALLBACK    0x0004
484 
485 /* Tell the PML that the copy is being done asynchronously
486  */
487 #define MCA_BTL_DES_FLAGS_CUDA_COPY_ASYNC   0x0008
488 
489 /* Type of transfer that will be done with this frag.
490  */
491 #define MCA_BTL_DES_FLAGS_PUT               0x0010
492 #define MCA_BTL_DES_FLAGS_GET               0x0020
493 
494 /* Ask the BTL to wake the remote process (send/sendi) or local process
495  * (put/get) to handle this message. The BTL may ignore this flag if
496  * signaled operations are not supported.
497  */
498 #define MCA_BTL_DES_FLAGS_SIGNAL            0x0040
499 
500 /**
501  * Maximum number of allowed segments in src/dst fields of a descriptor.
502  */
503 #define MCA_BTL_DES_MAX_SEGMENTS 16
504 
505 /**
506  * Maximum size of a BTL segment (NTH: does it really save us anything
507  * to hardcode this?)
508  */
509 #define MCA_BTL_SEG_MAX_SIZE 256
510 
511 /**
512  * Maximum size of a BTL registration handle in bytes
513  */
514 #define MCA_BTL_REG_HANDLE_MAX_SIZE 256
515 
516 /*
517  *  BTL base header, stores the tag at a minimum
518  */
519 struct mca_btl_base_header_t{
520     mca_btl_base_tag_t tag;
521 };
522 typedef struct mca_btl_base_header_t mca_btl_base_header_t;
523 
524 #define MCA_BTL_BASE_HEADER_HTON(hdr)
525 #define MCA_BTL_BASE_HEADER_NTOH(hdr)
526 
527 /*
528  *  BTL component interface functions and datatype.
529  */
530 
531 /**
532  * MCA->BTL Initializes the BTL component and creates specific BTL
533  * module(s).
534  *
535  * @param num_btls (OUT) Returns the number of btl modules created, or 0
536  *                       if the transport is not available.
537  *
538  * @param enable_progress_threads (IN) Whether this component is
539  * allowed to run a hidden/progress thread or not.
540  *
541  * @param enable_mpi_threads (IN) Whether support for multiple MPI
542  * threads is enabled or not (i.e., MPI_THREAD_MULTIPLE), which
543  * indicates whether multiple threads may invoke this component
544  * simultaneously or not.
545  *
546  * @return Array of pointers to BTL modules, or NULL if the transport
547  *         is not available.
548  *
549  * During component initialization, the BTL component should discover
550  * the physical devices that are available for the given transport,
551  * and create a BTL module to represent each device. Any addressing
552  * information required by peers to reach the device should be published
553  * during this function via the modex_send() interface.
554  *
555  */
556 
557 typedef struct mca_btl_base_module_t** (*mca_btl_base_component_init_fn_t)(
558     int *num_btls,
559     bool enable_progress_threads,
560     bool enable_mpi_threads
561 );
562 
563 /**
564  * MCA->BTL Called to progress outstanding requests for
565  * non-threaded polling environments.
566  *
567  * @return           Count of "completions", a metric of
568  *                   how many items where completed in the call
569  *                   to progress.
570  */
571 
572 typedef int (*mca_btl_base_component_progress_fn_t)(void);
573 
574 
575 /**
576  * Callback function that is called asynchronously on receipt
577  * of data by the transport layer.
578  * Note that the the mca_btl_base_descriptor_t is only valid within the
579  * completion function, this implies that all data payload in the
580  * mca_btl_base_descriptor_t must be copied out within this callback or
581  * forfeited back to the BTL.
582  * Note also that descriptor segments (des_segments) must be base
583  * segments for all callbacks.
584  *
585  * @param[IN] btl        BTL module
586  * @param[IN] tag        The active message receive callback tag value
587  * @param[IN] descriptor The BTL descriptor (contains the receive payload)
588  * @param[IN] cbdata     Opaque callback data
589  */
590 
591 typedef void (*mca_btl_base_module_recv_cb_fn_t)(
592     struct mca_btl_base_module_t* btl,
593     mca_btl_base_tag_t tag,
594     mca_btl_base_descriptor_t* descriptor,
595     void* cbdata
596 );
597 
598 typedef struct mca_btl_active_message_callback_t {
599     mca_btl_base_module_recv_cb_fn_t cbfunc;
600     void* cbdata;
601 } mca_btl_active_message_callback_t;
602 
603 OPAL_DECLSPEC extern
604 mca_btl_active_message_callback_t mca_btl_base_active_message_trigger[MCA_BTL_TAG_MAX];
605 
606 /**
607  *  BTL component descriptor. Contains component version information
608  *  and component open/close/init functions.
609  */
610 
611 struct mca_btl_base_component_3_0_0_t {
612   mca_base_component_t btl_version;
613   mca_base_component_data_t btl_data;
614   mca_btl_base_component_init_fn_t btl_init;
615   mca_btl_base_component_progress_fn_t btl_progress;
616 };
617 typedef struct mca_btl_base_component_3_0_0_t mca_btl_base_component_3_0_0_t;
618 typedef struct mca_btl_base_component_3_0_0_t mca_btl_base_component_t;
619 
620 /*  add the 2_0_0_t typedef for source compatibility
621  *  we can do this safely because 2_0_0 components are the same as
622  *  3_0_0 components, the difference is in the btl module.
623  *  Unfortunately 2_0_0 modules are not compatible with BTL 3_0_0 and
624  *  can not be used with the new interface.
625  */
626 typedef struct mca_btl_base_component_3_0_0_t mca_btl_base_component_2_0_0_t;
627 
628 
629 /*
630  * BTL module interface functions and datatype.
631  */
632 
633 /**
634  * MCA->BTL Clean up any resources held by BTL module
635  * before the module is unloaded.
636  *
637  * @param btl (IN)   BTL module.
638  * @return           OPAL_SUCCESS or error status on failure.
639  *
640  * Prior to unloading a BTL module, the MCA framework will call
641  * the BTL finalize method of the module. Any resources held by
642  * the BTL should be released and if required the memory corresponding
643  * to the BTL module freed.
644  *
645  */
646 typedef int (*mca_btl_base_module_finalize_fn_t)(
647     struct mca_btl_base_module_t* btl
648 );
649 
650 /**
651  * BML->BTL notification of change in the process list.
652  *
653  * @param btl (IN)            BTL module
654  * @param nprocs (IN)         Number of processes
655  * @param procs (IN)          Array of processes
656  * @param endpoint (OUT)      Array of mca_btl_base_endpoint_t structures by BTL.
657  * @param reachable (OUT)     Bitmask indicating set of peer processes that are reachable by this BTL.
658  * @return                    OPAL_SUCCESS or error status on failure.
659  *
660  * The mca_btl_base_module_add_procs_fn_t() is called by the BML to
661  * determine the set of BTLs that should be used to reach each process.
662  * Any addressing information exported by the peer via the modex_send()
663  * function should be available during this call via the corresponding
664  * modex_recv() function. The BTL may utilize this information to
665  * determine reachability of each peer process.
666  *
667  * The caller may pass a "reachable" bitmap pointer.  If it is not
668  * NULL, for each process that is reachable by the BTL, the bit
669  * corresponding to the index into the proc array (nprocs) should be
670  * set in the reachable bitmask. The BTL will return an array of
671  * pointers to a data structure defined by the BTL that is then
672  * returned to the BTL on subsequent calls to the BTL data transfer
673  * functions (e.g btl_send). This may be used by the BTL to cache any
674  * addressing or connection information (e.g. TCP socket, IB queue
675  * pair).
676  */
677 typedef int (*mca_btl_base_module_add_procs_fn_t)(
678     struct mca_btl_base_module_t* btl,
679     size_t nprocs,
680     struct opal_proc_t** procs,
681     struct mca_btl_base_endpoint_t** endpoints,
682     struct opal_bitmap_t* reachable
683 );
684 
685 /**
686  * Notification of change to the process list.
687  *
688  * @param btl (IN)     BTL module
689  * @param nprocs (IN)  Number of processes
690  * @param proc (IN)    Set of processes
691  * @param peer (IN)    Set of peer addressing information.
692  * @return             Status indicating if cleanup was successful
693  *
694  * When the process list changes, the BML notifies the BTL of the
695  * change, to provide the opportunity to cleanup or release any
696  * resources associated with the peer.
697  */
698 typedef int (*mca_btl_base_module_del_procs_fn_t)(
699     struct mca_btl_base_module_t* btl,
700     size_t nprocs,
701     struct opal_proc_t** procs,
702     struct mca_btl_base_endpoint_t** peer
703 );
704 
705 /**
706  * Register a callback function that is called on receipt
707  * of a fragment.
708  *
709  * @param[IN] btl      BTL module
710  * @param[IN] tag      tag value of this callback
711  *                     (specified on subsequent send operations)
712  * @param[IN] cbfunc   The callback function
713  * @param[IN] cbdata   Opaque callback data
714  *
715  * @return OPAL_SUCCESS The callback was registered successfully
716  * @return OPAL_ERROR   The callback was NOT registered successfully
717  *
718  */
719 typedef int (*mca_btl_base_module_register_fn_t)(
720     struct mca_btl_base_module_t* btl,
721     mca_btl_base_tag_t tag,
722     mca_btl_base_module_recv_cb_fn_t cbfunc,
723     void* cbdata
724 );
725 
726 
727 /**
728  * Callback function that is called asynchronously on receipt
729  * of an error from the transport layer
730  *
731  * @param[IN] btl     BTL module
732  * @param[IN] flags   type of error
733  * @param[IN] errproc process that had an error
734  * @param[IN] btlinfo descriptive string from the BTL
735  */
736 
737 typedef void (*mca_btl_base_module_error_cb_fn_t)(
738         struct mca_btl_base_module_t* btl,
739         int32_t flags,
740         struct opal_proc_t* errproc,
741         char* btlinfo
742 );
743 
744 
745 /**
746  * Register a callback function that is called on receipt
747  * of an error.
748  *
749  * @param[IN] btl       BTL module
750  * @param[IN] cbfunc    The callback function
751  *
752  * @return OPAL_SUCCESS The callback was registered successfully
753  * @return OPAL_ERROR   The callback was NOT registered successfully
754  *
755  */
756 typedef int (*mca_btl_base_module_register_error_fn_t)(
757     struct mca_btl_base_module_t* btl,
758     mca_btl_base_module_error_cb_fn_t cbfunc
759 );
760 
761 
762 /**
763  * Allocate a descriptor with a segment of the requested size.
764  * Note that the BTL layer may choose to return a smaller size
765  * if it cannot support the request. The order tag value ensures that
766  * operations on the descriptor that is allocated will be
767  * ordered w.r.t. a previous operation on a particular descriptor.
768  * Ordering is only guaranteed if the previous descriptor had its
769  * local completion callback function called and the order tag of
770  * that descriptor is only valid upon the local completion callback function.
771  *
772  *
773  * @param btl (IN)      BTL module
774  * @param size (IN)     Request segment size.
775  * @param order (IN)    The ordering tag (may be MCA_BTL_NO_ORDER)
776  */
777 
778 typedef mca_btl_base_descriptor_t* (*mca_btl_base_module_alloc_fn_t)(
779     struct mca_btl_base_module_t* btl,
780     struct mca_btl_base_endpoint_t* endpoint,
781     uint8_t order,
782     size_t size,
783     uint32_t flags
784 );
785 
786 /**
787  * Return a descriptor allocated from this BTL via alloc/prepare.
788  * A descriptor can only be deallocated after its local completion
789  * callback function has called for all send/put/get operations.
790  *
791  * @param btl (IN)      BTL module
792  * @param segment (IN)  Descriptor allocated from the BTL
793  */
794 typedef int (*mca_btl_base_module_free_fn_t)(
795     struct mca_btl_base_module_t* btl,
796     mca_btl_base_descriptor_t* descriptor
797 );
798 
799 
800 /**
801  * Prepare a descriptor for send using the supplied convertor. If the convertor
802  * references data that is contiguous, the descriptor may simply point to the
803  * user buffer. Otherwise, this routine is responsible for allocating buffer
804  * space and packing if required.
805  *
806  * The order tag value ensures that operations on the
807  * descriptor that is prepared will be ordered w.r.t. a previous
808  * operation on a particular descriptor. Ordering is only guaranteed if
809  * the previous descriptor had its local completion callback function
810  * called and the order tag of that descriptor is only valid upon the local
811  * completion callback function.
812  *
813  * @param btl (IN)          BTL module
814  * @param endpoint (IN)     BTL peer addressing
815  * @param registration (IN) Memory registration
816  * @param convertor (IN)    Data type convertor
817  * @param order (IN)        The ordering tag (may be MCA_BTL_NO_ORDER)
818  * @param reserve (IN)      Additional bytes requested by upper layer to precede user data
819  * @param size (IN/OUT)     Number of bytes to prepare (IN),
820  *                          number of bytes actually prepared (OUT)
821  *
822  */
823 typedef struct mca_btl_base_descriptor_t* (*mca_btl_base_module_prepare_fn_t)(
824     struct mca_btl_base_module_t* btl,
825     struct mca_btl_base_endpoint_t* endpoint,
826     struct opal_convertor_t* convertor,
827     uint8_t order,
828     size_t reserve,
829     size_t* size,
830     uint32_t flags
831 );
832 
833 /**
834  * @brief Register a memory region for put/get/atomic operations.
835  *
836  * @param btl (IN)         BTL module
837  * @param endpoint(IN)     BTL addressing information (or NULL for all endpoints)
838  * @param base (IN)        Pointer to start of region
839  * @param size (IN)        Size of region
840  * @param flags (IN)       Flags including access permissions
841  *
842  * @returns a memory registration handle valid for both local and remote operations
843  * @returns NULL if the region could not be registered
844  *
845  * This function registers the specified region with the hardware for use with
846  * the btl_put, btl_get, btl_atomic_cas, btl_atomic_op, and btl_atomic_fop
847  * functions. Care should be taken to not hold an excessive number of registrations
848  * as they may use limited system/NIC resources.
849  *
850  * Ownership of the memory pointed to by the returned (struct
851  * mca_btl_base_registration_handle_t*) is passed to the caller.  The
852  * BTL module cannot free or reuse the handle until it is returned via
853  * the mca_btl_base_module_deregister_mem_fn_t function.
854  */
855 typedef struct mca_btl_base_registration_handle_t *(*mca_btl_base_module_register_mem_fn_t)(
856     struct mca_btl_base_module_t* btl, struct mca_btl_base_endpoint_t *endpoint, void *base,
857     size_t size, uint32_t flags);
858 
859 /**
860  * @brief Deregister a memory region
861  *
862  * @param btl (IN)         BTL module region was registered with
863  * @param handle (IN)      BTL registration handle to deregister
864  *
865  * This function deregisters the memory region associated with the specified handle. Care
866  * should be taken to not perform any RDMA or atomic operation on this memory region
867  * after it is deregistered. It is erroneous to specify a memory handle associated with
868  * a remote node.
869  *
870  * The handle passed in will be a value previously returned by the
871  * mca_btl_base_module_register_mem_fn_t function.  Ownership of the
872  * memory pointed to by handle passes to the BTL module; this function
873  * is now is allowed to free the memory, return it to a freelist, etc.
874  */
875 typedef int (*mca_btl_base_module_deregister_mem_fn_t)(
876     struct mca_btl_base_module_t* btl, struct mca_btl_base_registration_handle_t *handle);
877 
878 /**
879  * Initiate an asynchronous send.
880  * Completion Semantics: the descriptor has been queued for a send operation
881  *                       the BTL now controls the descriptor until local
882  *                       completion callback is made on the descriptor
883  *
884  * All BTLs allow multiple concurrent asynchronous send operations on a descriptor
885  *
886  * @param btl (IN)         BTL module
887  * @param endpoint (IN)    BTL addressing information
888  * @param descriptor (IN)  Description of the data to be transfered
889  * @param tag (IN)         The tag value used to notify the peer.
890  *
891  * @retval OPAL_SUCCESS    The descriptor was successfully queued for a send
892  * @retval OPAL_ERROR      The descriptor was NOT successfully queued for a send
893  * @retval OPAL_ERR_UNREACH The endpoint is not reachable
894  */
895 typedef int (*mca_btl_base_module_send_fn_t)(
896     struct mca_btl_base_module_t* btl,
897     struct mca_btl_base_endpoint_t* endpoint,
898     struct mca_btl_base_descriptor_t* descriptor,
899     mca_btl_base_tag_t tag
900 );
901 
902 /**
903  * Initiate an immediate blocking send.
904  * Completion Semantics: the BTL will make a best effort
905  *  to send the header and "size" bytes from the datatype using the convertor.
906  *  The header is guaranteed to be delivered entirely in the first segment.
907  *  Should the BTL be unable to deliver the data due to resource constraints
908  *  the BTL will return a descriptor (via the OUT param)
909  *  of size "payload_size + header_size".
910  *
911  * @param btl (IN)             BTL module
912  * @param endpoint (IN)        BTL addressing information
913  * @param convertor (IN)       Data type convertor
914  * @param header (IN)          Pointer to header.
915  * @param header_size (IN)     Size of header.
916  * @param payload_size (IN)    Size of payload (from convertor).
917  * @param order (IN)           The ordering tag (may be MCA_BTL_NO_ORDER)
918  * @param flags (IN)           Flags.
919  * @param tag (IN)             The tag value used to notify the peer.
920  * @param descriptor (OUT)     The descriptor to be returned unable to be sent immediately
921  *                             (may be NULL).
922  *
923  * @retval OPAL_SUCCESS           The send was successfully queued
924  * @retval OPAL_ERROR             The send failed
925  * @retval OPAL_ERR_UNREACH       The endpoint is not reachable
926  * @retval OPAL_ERR_RESOURCE_BUSY The BTL is busy a descriptor will be returned
927  *                                (via the OUT param) if descriptors are available
928  */
929 
930 typedef int (*mca_btl_base_module_sendi_fn_t)(
931     struct mca_btl_base_module_t* btl,
932     struct mca_btl_base_endpoint_t* endpoint,
933     struct opal_convertor_t* convertor,
934     void* header,
935     size_t header_size,
936     size_t payload_size,
937     uint8_t order,
938     uint32_t flags,
939     mca_btl_base_tag_t tag,
940     mca_btl_base_descriptor_t** descriptor
941  );
942 
943 /**
944  * Initiate an asynchronous put.
945  * Completion Semantics: if this function returns a 1 then the operation
946  *                       is complete. a return of OPAL_SUCCESS indicates
947  *                       the put operation has been queued with the
948  *                       network. the local_handle can not be deregistered
949  *                       until all outstanding operations on that handle
950  *                       have been completed.
951  *
952  * @param btl (IN)            BTL module
953  * @param endpoint (IN)       BTL addressing information
954  * @param local_address (IN)  Local address to put from (registered)
955  * @param remote_address (IN) Remote address to put to (registered remotely)
956  * @param local_handle (IN)   Registration handle for region containing
957  *                            (local_address, local_address + size)
958  * @param remote_handle (IN)  Remote registration handle for region containing
959  *                            (remote_address, remote_address + size)
960  * @param size (IN)           Number of bytes to put
961  * @param flags (IN)          Flags for this put operation
962  * @param order (IN)          Ordering
963  * @param cbfunc (IN)         Function to call on completion (if queued)
964  * @param cbcontext (IN)      Context for the callback
965  * @param cbdata (IN)         Data for callback
966  *
967  * @retval OPAL_SUCCESS    The descriptor was successfully queued for a put
968  * @retval OPAL_ERROR      The descriptor was NOT successfully queued for a put
969  * @retval OPAL_ERR_OUT_OF_RESOURCE  Insufficient resources to queue the put
970  *                         operation. Try again later
971  * @retval OPAL_ERR_NOT_AVAILABLE  Put can not be performed due to size or
972  *                         alignment restrictions.
973  */
974 typedef int (*mca_btl_base_module_put_fn_t) (struct mca_btl_base_module_t *btl,
975     struct mca_btl_base_endpoint_t *endpoint, void *local_address,
976     uint64_t remote_address, struct mca_btl_base_registration_handle_t *local_handle,
977     struct mca_btl_base_registration_handle_t *remote_handle, size_t size, int flags,
978     int order, mca_btl_base_rdma_completion_fn_t cbfunc, void *cbcontext, void *cbdata);
979 
980 /**
981  * Initiate an asynchronous get.
982  * Completion Semantics: if this function returns a 1 then the operation
983  *                       is complete. a return of OPAL_SUCCESS indicates
984  *                       the get operation has been queued with the
985  *                       network. the local_handle can not be deregistered
986  *                       until all outstanding operations on that handle
987  *                       have been completed.
988  *
989  * @param btl (IN)            BTL module
990  * @param endpoint (IN)       BTL addressing information
991  * @param local_address (IN)  Local address to put from (registered)
992  * @param remote_address (IN) Remote address to put to (registered remotely)
993  * @param local_handle (IN)   Registration handle for region containing
994  *                            (local_address, local_address + size)
995  * @param remote_handle (IN)  Remote registration handle for region containing
996  *                            (remote_address, remote_address + size)
997  * @param size (IN)           Number of bytes to put
998  * @param flags (IN)          Flags for this put operation
999  * @param order (IN)          Ordering
1000  * @param cbfunc (IN)         Function to call on completion (if queued)
1001  * @param cbcontext (IN)      Context for the callback
1002  * @param cbdata (IN)         Data for callback
1003  *
1004  * @retval OPAL_SUCCESS    The descriptor was successfully queued for a put
1005  * @retval OPAL_ERROR      The descriptor was NOT successfully queued for a put
1006  * @retval OPAL_ERR_OUT_OF_RESOURCE  Insufficient resources to queue the put
1007  *                         operation. Try again later
1008  * @retval OPAL_ERR_NOT_AVAILABLE  Put can not be performed due to size or
1009  *                         alignment restrictions.
1010  */
1011 typedef int (*mca_btl_base_module_get_fn_t) (struct mca_btl_base_module_t *btl,
1012     struct mca_btl_base_endpoint_t *endpoint, void *local_address,
1013     uint64_t remote_address, struct mca_btl_base_registration_handle_t *local_handle,
1014     struct mca_btl_base_registration_handle_t *remote_handle, size_t size, int flags,
1015     int order, mca_btl_base_rdma_completion_fn_t cbfunc, void *cbcontext, void *cbdata);
1016 
1017 /**
1018  * Initiate an asynchronous atomic operation.
1019  * Completion Semantics: if this function returns a 1 then the operation
1020  *                       is complete. a return of OPAL_SUCCESS indicates
1021  *                       the atomic operation has been queued with the
1022  *                       network.
1023  *
1024  * @param btl (IN)            BTL module
1025  * @param endpoint (IN)       BTL addressing information
1026  * @param remote_address (IN) Remote address to put to (registered remotely)
1027  * @param remote_handle (IN)  Remote registration handle for region containing
1028  *                            (remote_address, remote_address + 8)
1029  * @param op (IN)             Operation to perform
1030  * @param operand (IN)        Operand for the operation
1031  * @param flags (IN)          Flags for this atomic operation
1032  * @param order (IN)          Ordering
1033  * @param cbfunc (IN)         Function to call on completion (if queued)
1034  * @param cbcontext (IN)      Context for the callback
1035  * @param cbdata (IN)         Data for callback
1036  *
1037  * @retval OPAL_SUCCESS    The operation was successfully queued
1038  * @retval 1               The operation is complete
1039  * @retval OPAL_ERROR      The operation was NOT successfully queued
1040  * @retval OPAL_ERR_OUT_OF_RESOURCE  Insufficient resources to queue the atomic
1041  *                         operation. Try again later
1042  * @retval OPAL_ERR_NOT_AVAILABLE  Atomic operation can not be performed due to
1043  *                         alignment restrictions or the operation {op} is not supported
1044  *                         by the hardware.
1045  *
1046  * After the operation is complete the remote address specified by {remote_address} and
1047  * {remote_handle} will be updated with (*remote_address) = (*remote_address) op operand.
1048  * The btl will guarantee consistency of atomic operations performed via the btl. Note,
1049  * however, that not all btls will provide consistency between btl atomic operations and
1050  * cpu or other btl atomics.
1051  */
1052 typedef int (*mca_btl_base_module_atomic_op64_fn_t) (struct mca_btl_base_module_t *btl,
1053     struct mca_btl_base_endpoint_t *endpoint, uint64_t remote_address,
1054     struct mca_btl_base_registration_handle_t *remote_handle, mca_btl_base_atomic_op_t op,
1055     uint64_t operand, int flags, int order, mca_btl_base_rdma_completion_fn_t cbfunc,
1056     void *cbcontext, void *cbdata);
1057 
1058 /**
1059  * Initiate an asynchronous fetching atomic operation.
1060  * Completion Semantics: if this function returns a 1 then the operation
1061  *                       is complete. a return of OPAL_SUCCESS indicates
1062  *                       the atomic operation has been queued with the
1063  *                       network.
1064  *
1065  * @param btl (IN)            BTL module
1066  * @param endpoint (IN)       BTL addressing information
1067  * @param local_address (OUT) Local address to store the result in
1068  * @param remote_address (IN) Remote address perfom operation on to (registered remotely)
1069  * @param local_handle (IN)   Local registration handle for region containing
1070  *                            (local_address, local_address + 8)
1071  * @param remote_handle (IN)  Remote registration handle for region containing
1072  *                            (remote_address, remote_address + 8)
1073  * @param op (IN)             Operation to perform
1074  * @param operand (IN)        Operand for the operation
1075  * @param flags (IN)          Flags for this atomic operation
1076  * @param order (IN)          Ordering
1077  * @param cbfunc (IN)         Function to call on completion (if queued)
1078  * @param cbcontext (IN)      Context for the callback
1079  * @param cbdata (IN)         Data for callback
1080  *
1081  * @retval OPAL_SUCCESS    The operation was successfully queued
1082  * @retval 1               The operation is complete
1083  * @retval OPAL_ERROR      The operation was NOT successfully queued
1084  * @retval OPAL_ERR_OUT_OF_RESOURCE  Insufficient resources to queue the atomic
1085  *                         operation. Try again later
1086  * @retval OPAL_ERR_NOT_AVAILABLE  Atomic operation can not be performed due to
1087  *                         alignment restrictions or the operation {op} is not supported
1088  *                         by the hardware.
1089  *
1090  * After the operation is complete the remote address specified by {remote_address} and
1091  * {remote_handle} will be updated with (*remote_address) = (*remote_address) op operand.
1092  * {local_address} will be updated with the previous value stored in {remote_address}.
1093  * The btl will guarantee consistency of atomic operations performed via the btl. Note,
1094  * however, that not all btls will provide consistency between btl atomic operations and
1095  * cpu or other btl atomics.
1096  */
1097 typedef int (*mca_btl_base_module_atomic_fop64_fn_t) (struct mca_btl_base_module_t *btl,
1098     struct mca_btl_base_endpoint_t *endpoint, void *local_address, uint64_t remote_address,
1099     struct mca_btl_base_registration_handle_t *local_handle,
1100     struct mca_btl_base_registration_handle_t *remote_handle, mca_btl_base_atomic_op_t op,
1101     uint64_t operand, int flags, int order, mca_btl_base_rdma_completion_fn_t cbfunc,
1102     void *cbcontext, void *cbdata);
1103 
1104 /**
1105  * Initiate an asynchronous compare and swap operation.
1106  * Completion Semantics: if this function returns a 1 then the operation
1107  *                       is complete. a return of OPAL_SUCCESS indicates
1108  *                       the atomic operation has been queued with the
1109  *                       network.
1110  *
1111  * @param btl (IN)            BTL module
1112  * @param endpoint (IN)       BTL addressing information
1113  * @param local_address (OUT) Local address to store the result in
1114  * @param remote_address (IN) Remote address perfom operation on to (registered remotely)
1115  * @param local_handle (IN)   Local registration handle for region containing
1116  *                            (local_address, local_address + 8)
1117  * @param remote_handle (IN)  Remote registration handle for region containing
1118  *                            (remote_address, remote_address + 8)
1119  * @param compare (IN)        Operand for the operation
1120  * @param value (IN)          Value to store on success
1121  * @param flags (IN)          Flags for this atomic operation
1122  * @param order (IN)          Ordering
1123  * @param cbfunc (IN)         Function to call on completion (if queued)
1124  * @param cbcontext (IN)      Context for the callback
1125  * @param cbdata (IN)         Data for callback
1126  *
1127  * @retval OPAL_SUCCESS    The operation was successfully queued
1128  * @retval 1               The operation is complete
1129  * @retval OPAL_ERROR      The operation was NOT successfully queued
1130  * @retval OPAL_ERR_OUT_OF_RESOURCE  Insufficient resources to queue the atomic
1131  *                         operation. Try again later
1132  * @retval OPAL_ERR_NOT_AVAILABLE  Atomic operation can not be performed due to
1133  *                         alignment restrictions or the operation {op} is not supported
1134  *                         by the hardware.
1135  *
1136  * After the operation is complete the remote address specified by {remote_address} and
1137  * {remote_handle} will be updated with {value} if *remote_address == compare.
1138  * {local_address} will be updated with the previous value stored in {remote_address}.
1139  * The btl will guarantee consistency of atomic operations performed via the btl. Note,
1140  * however, that not all btls will provide consistency between btl atomic operations and
1141  * cpu atomics.
1142  */
1143 typedef int (*mca_btl_base_module_atomic_cswap64_fn_t) (struct mca_btl_base_module_t *btl,
1144     struct mca_btl_base_endpoint_t *endpoint, void *local_address, uint64_t remote_address,
1145     struct mca_btl_base_registration_handle_t *local_handle,
1146     struct mca_btl_base_registration_handle_t *remote_handle, uint64_t compare,
1147     uint64_t value, int flags, int order, mca_btl_base_rdma_completion_fn_t cbfunc,
1148     void *cbcontext, void *cbdata);
1149 
1150 /**
1151  * Diagnostic dump of btl state.
1152  *
1153  * @param btl (IN)         BTL module
1154  * @param endpoint (IN)    BTL endpoint
1155  * @param verbose (IN)     Verbosity level
1156  */
1157 
1158 typedef void (*mca_btl_base_module_dump_fn_t)(
1159     struct mca_btl_base_module_t* btl,
1160     struct mca_btl_base_endpoint_t* endpoint,
1161     int verbose
1162 );
1163 
1164 /**
1165  * Fault Tolerance Event Notification Function
1166  * @param state Checkpoint Status
1167  * @return OPAL_SUCCESS or failure status
1168  */
1169 typedef int (*mca_btl_base_module_ft_event_fn_t)(int state);
1170 
1171 /**
1172  * Flush all outstanding RDMA operations on an endpoint or all endpoints.
1173  *
1174  * @param btl (IN)         BTL module
1175  * @param endpoint (IN)    Endpoint to flush (NULL == all)
1176  *
1177  * This function returns when all outstanding RDMA (put, get, atomic) operations
1178  * that were started prior to the flush call have completed. This call does
1179  * NOT guarantee that all BTL callbacks have been completed.
1180  *
1181  * The BTL is allowed to ignore the endpoint parameter and flush *all* endpoints.
1182  */
1183 typedef int (*mca_btl_base_module_flush_fn_t) (struct mca_btl_base_module_t *btl, struct mca_btl_base_endpoint_t *endpoint);
1184 
1185 /**
1186  * BTL module interface functions and attributes.
1187  */
1188 struct mca_btl_base_module_t {
1189 
1190     /* BTL common attributes */
1191     mca_btl_base_component_t* btl_component; /**< pointer back to the BTL component structure */
1192     size_t      btl_eager_limit;      /**< maximum size of first fragment -- eager send */
1193     size_t      btl_rndv_eager_limit;    /**< the size of a data sent in a first fragment of rendezvous protocol */
1194     size_t      btl_max_send_size;    /**< maximum send fragment size supported by the BTL */
1195     size_t      btl_rdma_pipeline_send_length; /**< amount of bytes that should be send by pipeline protocol */
1196     size_t      btl_rdma_pipeline_frag_size; /**< maximum rdma fragment size supported by the BTL */
1197     size_t      btl_min_rdma_pipeline_size; /**< minimum packet size for pipeline protocol  */
1198     uint32_t    btl_exclusivity;      /**< indicates this BTL should be used exclusively */
1199     uint32_t    btl_latency;          /**< relative ranking of latency used to prioritize btls */
1200     uint32_t    btl_bandwidth;        /**< bandwidth (Mbytes/sec) supported by each endpoint */
1201     uint32_t    btl_flags;            /**< flags (put/get...) */
1202     uint32_t    btl_atomic_flags;     /**< atomic operations supported (add, and, xor, etc) */
1203     size_t      btl_registration_handle_size; /**< size of the BTLs registration handles */
1204 
1205     /* One-sided limitations (0 for no alignment, SIZE_MAX for no limit ) */
1206     size_t      btl_get_limit;        /**< maximum size supported by the btl_get function */
1207     size_t      btl_get_alignment;    /**< minimum alignment/size needed by btl_get (power of 2) */
1208     size_t      btl_put_limit;        /**< maximum size supported by the btl_put function */
1209     size_t      btl_put_alignment;    /**< minimum alignment/size needed by btl_put (power of 2) */
1210 
1211     /* minimum transaction sizes for which registration is required for local memory */
1212     size_t      btl_get_local_registration_threshold;
1213     size_t      btl_put_local_registration_threshold;
1214 
1215     /* BTL function table */
1216     mca_btl_base_module_add_procs_fn_t      btl_add_procs;
1217     mca_btl_base_module_del_procs_fn_t      btl_del_procs;
1218     mca_btl_base_module_register_fn_t       btl_register;
1219     mca_btl_base_module_finalize_fn_t       btl_finalize;
1220 
1221     mca_btl_base_module_alloc_fn_t          btl_alloc;
1222     mca_btl_base_module_free_fn_t           btl_free;
1223     mca_btl_base_module_prepare_fn_t        btl_prepare_src;
1224     mca_btl_base_module_send_fn_t           btl_send;
1225     mca_btl_base_module_sendi_fn_t          btl_sendi;
1226     mca_btl_base_module_put_fn_t            btl_put;
1227     mca_btl_base_module_get_fn_t            btl_get;
1228     mca_btl_base_module_dump_fn_t           btl_dump;
1229 
1230     /* atomic operations */
1231     mca_btl_base_module_atomic_op64_fn_t    btl_atomic_op;
1232     mca_btl_base_module_atomic_fop64_fn_t   btl_atomic_fop;
1233     mca_btl_base_module_atomic_cswap64_fn_t btl_atomic_cswap;
1234 
1235     /* new memory registration functions */
1236     mca_btl_base_module_register_mem_fn_t   btl_register_mem;   /**< memory registration function (NULL if not needed) */
1237     mca_btl_base_module_deregister_mem_fn_t btl_deregister_mem; /**< memory deregistration function (NULL if not needed) */
1238 
1239     /** the mpool associated with this btl (optional) */
1240     mca_mpool_base_module_t*             btl_mpool;
1241     /** register a default error handler */
1242     mca_btl_base_module_register_error_fn_t btl_register_error;
1243     /** fault tolerant even notification */
1244     mca_btl_base_module_ft_event_fn_t btl_ft_event;
1245 #if OPAL_CUDA_GDR_SUPPORT
1246     size_t      btl_cuda_eager_limit;  /**< switch from eager to RDMA */
1247     size_t      btl_cuda_rdma_limit;   /**< switch from RDMA to rndv pipeline */
1248 #endif /* OPAL_CUDA_GDR_SUPPORT */
1249 #if OPAL_CUDA_SUPPORT
1250     size_t      btl_cuda_max_send_size;   /**< set if CUDA max send_size is different from host max send size */
1251 #endif /* OPAL_CUDA_SUPPORT */
1252 
1253     mca_btl_base_module_flush_fn_t btl_flush; /**< flush all previous operations on an endpoint */
1254 
1255     unsigned char padding[256]; /**< padding to future-proof the btl module */
1256 };
1257 typedef struct mca_btl_base_module_t mca_btl_base_module_t;
1258 
1259 /*
1260  * Macro for use in modules that are of type btl v3.1.0
1261  */
1262 #define MCA_BTL_BASE_VERSION_3_1_0              \
1263     OPAL_MCA_BASE_VERSION_2_1_0("btl", 3, 1, 0)
1264 
1265 #define MCA_BTL_DEFAULT_VERSION(name)                       \
1266     MCA_BTL_BASE_VERSION_3_1_0,                             \
1267     .mca_component_name = name,                             \
1268     MCA_BASE_MAKE_VERSION(component, OPAL_MAJOR_VERSION, OPAL_MINOR_VERSION, \
1269                           OPAL_RELEASE_VERSION)
1270 
1271 /**
1272  * Convinience macro for detecting the BTL interface version.
1273  */
1274 #define BTL_VERSION 310
1275 
1276 END_C_DECLS
1277 
1278 #endif /* OPAL_MCA_BTL_H */
1279