6 * Mellanox Arbel Infiniband HCA driver
10 FILE_LICENCE ( GPL2_OR_LATER );
13 #include <ipxe/uaccess.h>
14 #include <ipxe/ib_packet.h>
15 #include "mlx_bitops.h"
16 #include "MT25218_PRM.h"
23 /* Ports in existence */
24 #define ARBEL_NUM_PORTS 2
25 #define ARBEL_PORT_BASE 1
28 #define ARBEL_PCI_CONFIG_BAR PCI_BASE_ADDRESS_0
29 #define ARBEL_PCI_CONFIG_BAR_SIZE 0x100000
30 #define ARBEL_PCI_UAR_BAR PCI_BASE_ADDRESS_2
31 #define ARBEL_PCI_UAR_IDX 1
32 #define ARBEL_PCI_UAR_SIZE 0x1000
35 #define ARBEL_RESET_OFFSET 0x0f0010
36 #define ARBEL_RESET_MAGIC 0x01000000UL
37 #define ARBEL_RESET_WAIT_TIME_MS 1000
39 /* UAR context table (UCE) resource types */
40 #define ARBEL_UAR_RES_NONE 0x00
41 #define ARBEL_UAR_RES_CQ_CI 0x01
42 #define ARBEL_UAR_RES_CQ_ARM 0x02
43 #define ARBEL_UAR_RES_SQ 0x03
44 #define ARBEL_UAR_RES_RQ 0x04
45 #define ARBEL_UAR_RES_GROUP_SEP 0x07
47 /* Work queue entry and completion queue entry opcodes */
48 #define ARBEL_OPCODE_SEND 0x0a
49 #define ARBEL_OPCODE_RECV_ERROR 0xfe
50 #define ARBEL_OPCODE_SEND_ERROR 0xff
52 /* HCA command register opcodes */
53 #define ARBEL_HCR_QUERY_DEV_LIM 0x0003
54 #define ARBEL_HCR_QUERY_FW 0x0004
55 #define ARBEL_HCR_INIT_HCA 0x0007
56 #define ARBEL_HCR_CLOSE_HCA 0x0008
57 #define ARBEL_HCR_INIT_IB 0x0009
58 #define ARBEL_HCR_CLOSE_IB 0x000a
59 #define ARBEL_HCR_SW2HW_MPT 0x000d
60 #define ARBEL_HCR_MAP_EQ 0x0012
61 #define ARBEL_HCR_SW2HW_EQ 0x0013
62 #define ARBEL_HCR_HW2SW_EQ 0x0014
63 #define ARBEL_HCR_SW2HW_CQ 0x0016
64 #define ARBEL_HCR_HW2SW_CQ 0x0017
65 #define ARBEL_HCR_QUERY_CQ 0x0018
66 #define ARBEL_HCR_RST2INIT_QPEE 0x0019
67 #define ARBEL_HCR_INIT2RTR_QPEE 0x001a
68 #define ARBEL_HCR_RTR2RTS_QPEE 0x001b
69 #define ARBEL_HCR_RTS2RTS_QPEE 0x001c
70 #define ARBEL_HCR_2RST_QPEE 0x0021
71 #define ARBEL_HCR_QUERY_QPEE 0x0022
72 #define ARBEL_HCR_CONF_SPECIAL_QP 0x0023
73 #define ARBEL_HCR_MAD_IFC 0x0024
74 #define ARBEL_HCR_READ_MGM 0x0025
75 #define ARBEL_HCR_WRITE_MGM 0x0026
76 #define ARBEL_HCR_MGID_HASH 0x0027
77 #define ARBEL_HCR_RUN_FW 0x0ff6
78 #define ARBEL_HCR_DISABLE_LAM 0x0ff7
79 #define ARBEL_HCR_ENABLE_LAM 0x0ff8
80 #define ARBEL_HCR_UNMAP_ICM 0x0ff9
81 #define ARBEL_HCR_MAP_ICM 0x0ffa
82 #define ARBEL_HCR_UNMAP_ICM_AUX 0x0ffb
83 #define ARBEL_HCR_MAP_ICM_AUX 0x0ffc
84 #define ARBEL_HCR_SET_ICM_SIZE 0x0ffd
85 #define ARBEL_HCR_UNMAP_FA 0x0ffe
86 #define ARBEL_HCR_MAP_FA 0x0fff
89 #define ARBEL_ST_RC 0x00
90 #define ARBEL_ST_UD 0x03
91 #define ARBEL_ST_MLX 0x07
94 #define ARBEL_MTU_2048 0x04
96 #define ARBEL_NO_EQ 64
98 #define ARBEL_INVALID_LKEY 0x00000100UL
100 #define ARBEL_PAGE_SIZE ( ( size_t ) 4096 )
102 #define ARBEL_RDB_ENTRY_SIZE ( ( size_t ) 32 )
104 #define ARBEL_DB_POST_SND_OFFSET 0x10
105 #define ARBEL_DB_EQ_OFFSET(_eqn) ( 0x08 * (_eqn) )
107 #define ARBEL_QPEE_OPT_PARAM_QKEY 0x00000020UL
109 #define ARBEL_MAP_EQ ( 0UL << 31 )
110 #define ARBEL_UNMAP_EQ ( 1UL << 31 )
112 #define ARBEL_EV_PORT_STATE_CHANGE 0x09
114 #define ARBEL_LOG_MULTICAST_HASH_SIZE 3
116 #define ARBEL_PM_STATE_ARMED 0x00
117 #define ARBEL_PM_STATE_REARM 0x01
118 #define ARBEL_PM_STATE_MIGRATED 0x03
120 #define ARBEL_RETRY_MAX 0x07
123 * Datatypes that seem to be missing from the autogenerated documentation
126 struct arbelprm_mgm_hash_st {
127 pseudo_bit_t reserved0[0x00020];
129 pseudo_bit_t hash[0x00010];
130 pseudo_bit_t reserved1[0x00010];
131 } __attribute__ (( packed ));
133 struct arbelprm_scalar_parameter_st {
134 pseudo_bit_t reserved0[0x00020];
136 pseudo_bit_t value[0x00020];
137 } __attribute__ (( packed ));
139 struct arbelprm_event_mask_st {
140 pseudo_bit_t reserved0[0x00020];
142 pseudo_bit_t completion[0x00001];
143 pseudo_bit_t path_migration_succeeded[0x00001];
144 pseudo_bit_t communication_established[0x00001];
145 pseudo_bit_t send_queue_drained[0x00001];
146 pseudo_bit_t cq_error[0x00001];
147 pseudo_bit_t wq_catastrophe[0x00001];
148 pseudo_bit_t qpc_catastrophe[0x00001];
149 pseudo_bit_t path_migration_failed[0x00001];
150 pseudo_bit_t reserved1[0x00001];
151 pseudo_bit_t port_state_change[0x00001];
152 pseudo_bit_t command_done[0x00001];
153 pseudo_bit_t reserved2[0x00005];
154 pseudo_bit_t wq_invalid_request[0x00001];
155 pseudo_bit_t wq_access_violation[0x00001];
156 pseudo_bit_t srq_catastrophe[0x00001];
157 pseudo_bit_t srq_last_wqe[0x00001];
158 pseudo_bit_t srq_rq_limit[0x00001];
159 pseudo_bit_t gpio[0x00001];
160 pseudo_bit_t clientreregister[0x00001];
161 pseudo_bit_t path_migration_armed[0x00001];
162 pseudo_bit_t reserved3[0x00008];
163 } __attribute__ (( packed ));
165 struct arbelprm_eq_set_ci_st {
166 pseudo_bit_t ci[0x00020];
167 } __attribute__ (( packed ));
169 struct arbelprm_port_state_change_event_st {
170 pseudo_bit_t reserved[0x00020];
171 struct arbelprm_port_state_change_st data;
172 } __attribute__ (( packed ));
175 * Wrapper structures for hardware datatypes
179 struct MLX_DECLARE_STRUCT ( arbelprm_access_lam );
180 struct MLX_DECLARE_STRUCT ( arbelprm_completion_queue_context );
181 struct MLX_DECLARE_STRUCT ( arbelprm_completion_queue_entry );
182 struct MLX_DECLARE_STRUCT ( arbelprm_completion_with_error );
183 struct MLX_DECLARE_STRUCT ( arbelprm_cq_arm_db_record );
184 struct MLX_DECLARE_STRUCT ( arbelprm_cq_ci_db_record );
185 struct MLX_DECLARE_STRUCT ( arbelprm_event_mask );
186 struct MLX_DECLARE_STRUCT ( arbelprm_event_queue_entry );
187 struct MLX_DECLARE_STRUCT ( arbelprm_eq_set_ci );
188 struct MLX_DECLARE_STRUCT ( arbelprm_eqc );
189 struct MLX_DECLARE_STRUCT ( arbelprm_hca_command_register );
190 struct MLX_DECLARE_STRUCT ( arbelprm_init_hca );
191 struct MLX_DECLARE_STRUCT ( arbelprm_init_ib );
192 struct MLX_DECLARE_STRUCT ( arbelprm_mad_ifc );
193 struct MLX_DECLARE_STRUCT ( arbelprm_mgm_entry );
194 struct MLX_DECLARE_STRUCT ( arbelprm_mgm_hash );
195 struct MLX_DECLARE_STRUCT ( arbelprm_mpt );
196 struct MLX_DECLARE_STRUCT ( arbelprm_port_state_change_event );
197 struct MLX_DECLARE_STRUCT ( arbelprm_qp_db_record );
198 struct MLX_DECLARE_STRUCT ( arbelprm_qp_ee_state_transitions );
199 struct MLX_DECLARE_STRUCT ( arbelprm_query_dev_lim );
200 struct MLX_DECLARE_STRUCT ( arbelprm_query_fw );
201 struct MLX_DECLARE_STRUCT ( arbelprm_queue_pair_ee_context_entry );
202 struct MLX_DECLARE_STRUCT ( arbelprm_recv_wqe_segment_next );
203 struct MLX_DECLARE_STRUCT ( arbelprm_scalar_parameter );
204 struct MLX_DECLARE_STRUCT ( arbelprm_send_doorbell );
205 struct MLX_DECLARE_STRUCT ( arbelprm_ud_address_vector );
206 struct MLX_DECLARE_STRUCT ( arbelprm_virtual_physical_mapping );
207 struct MLX_DECLARE_STRUCT ( arbelprm_wqe_segment_ctrl_mlx );
208 struct MLX_DECLARE_STRUCT ( arbelprm_wqe_segment_ctrl_send );
209 struct MLX_DECLARE_STRUCT ( arbelprm_wqe_segment_data_ptr );
210 struct MLX_DECLARE_STRUCT ( arbelprm_wqe_segment_next );
211 struct MLX_DECLARE_STRUCT ( arbelprm_wqe_segment_ud );
214 * Composite hardware datatypes
218 #define ARBEL_MAX_GATHER 2
220 struct arbelprm_ud_send_wqe {
221 struct arbelprm_wqe_segment_next next;
222 struct arbelprm_wqe_segment_ctrl_send ctrl;
223 struct arbelprm_wqe_segment_ud ud;
224 struct arbelprm_wqe_segment_data_ptr data[ARBEL_MAX_GATHER];
225 } __attribute__ (( packed ));
227 struct arbelprm_mlx_send_wqe {
228 struct arbelprm_wqe_segment_next next;
229 struct arbelprm_wqe_segment_ctrl_mlx ctrl;
230 struct arbelprm_wqe_segment_data_ptr data[ARBEL_MAX_GATHER];
231 uint8_t headers[IB_MAX_HEADER_SIZE];
232 } __attribute__ (( packed ));
234 struct arbelprm_rc_send_wqe {
235 struct arbelprm_wqe_segment_next next;
236 struct arbelprm_wqe_segment_ctrl_send ctrl;
237 struct arbelprm_wqe_segment_data_ptr data[ARBEL_MAX_GATHER];
238 } __attribute__ (( packed ));
240 #define ARBEL_MAX_SCATTER 1
242 struct arbelprm_recv_wqe {
243 /* The autogenerated header is inconsistent between send and
244 * receive WQEs. The "ctrl" structure for receive WQEs is
245 * defined to include the "next" structure. Since the "ctrl"
246 * part of the "ctrl" structure contains only "reserved, must
247 * be zero" bits, we ignore its definition and provide
248 * something more usable.
250 struct arbelprm_recv_wqe_segment_next next;
251 uint32_t ctrl[2]; /* All "reserved, must be zero" */
252 struct arbelprm_wqe_segment_data_ptr data[ARBEL_MAX_SCATTER];
253 } __attribute__ (( packed ));
255 union arbelprm_completion_entry {
256 struct arbelprm_completion_queue_entry normal;
257 struct arbelprm_completion_with_error error;
258 } __attribute__ (( packed ));
260 union arbelprm_event_entry {
261 struct arbelprm_event_queue_entry generic;
262 struct arbelprm_port_state_change_event port_state_change;
263 } __attribute__ (( packed ));
265 union arbelprm_doorbell_record {
266 struct arbelprm_cq_arm_db_record cq_arm;
267 struct arbelprm_cq_ci_db_record cq_ci;
268 struct arbelprm_qp_db_record qp;
269 } __attribute__ (( packed ));
271 union arbelprm_doorbell_register {
272 struct arbelprm_send_doorbell send;
274 } __attribute__ (( packed ));
276 union arbelprm_eq_doorbell_register {
277 struct arbelprm_eq_set_ci ci;
279 } __attribute__ (( packed ));
282 struct arbelprm_mad_ifc ifc;
284 } __attribute__ (( packed ));
287 * iPXE-specific definitions
291 /** Arbel device limits */
292 struct arbel_dev_limits {
293 /** Number of reserved QPs */
294 unsigned int reserved_qps;
295 /** QP context entry size */
296 size_t qpc_entry_size;
297 /** Extended QP context entry size */
298 size_t eqpc_entry_size;
299 /** Number of reserved SRQs */
300 unsigned int reserved_srqs;
301 /** SRQ context entry size */
302 size_t srqc_entry_size;
303 /** Number of reserved EEs */
304 unsigned int reserved_ees;
305 /** EE context entry size */
306 size_t eec_entry_size;
307 /** Extended EE context entry size */
308 size_t eeec_entry_size;
309 /** Number of reserved CQs */
310 unsigned int reserved_cqs;
311 /** CQ context entry size */
312 size_t cqc_entry_size;
313 /** Number of reserved EQs */
314 unsigned int reserved_eqs;
315 /** Number of reserved MTTs */
316 unsigned int reserved_mtts;
317 /** MTT entry size */
318 size_t mtt_entry_size;
319 /** Number of reserved MRWs */
320 unsigned int reserved_mrws;
321 /** MPT entry size */
322 size_t mpt_entry_size;
323 /** Number of reserved RDBs */
324 unsigned int reserved_rdbs;
325 /** EQ context entry size */
326 size_t eqc_entry_size;
327 /** Number of reserved UARs */
328 unsigned int reserved_uars;
329 /** UAR scratchpad entry size */
330 size_t uar_scratch_entry_size;
333 /** Alignment of Arbel send work queue entries */
334 #define ARBEL_SEND_WQE_ALIGN 128
336 /** An Arbel send work queue entry */
337 union arbel_send_wqe {
338 struct arbelprm_wqe_segment_next next;
339 struct arbelprm_ud_send_wqe ud;
340 struct arbelprm_mlx_send_wqe mlx;
341 struct arbelprm_rc_send_wqe rc;
342 uint8_t force_align[ARBEL_SEND_WQE_ALIGN];
343 } __attribute__ (( packed ));
345 /** An Arbel send work queue */
346 struct arbel_send_work_queue {
347 /** Doorbell record number */
348 unsigned int doorbell_idx;
349 /** Work queue entries */
350 union arbel_send_wqe *wqe;
351 /** Size of work queue */
355 /** Alignment of Arbel receive work queue entries */
356 #define ARBEL_RECV_WQE_ALIGN 64
358 /** An Arbel receive work queue entry */
359 union arbel_recv_wqe {
360 struct arbelprm_recv_wqe recv;
361 uint8_t force_align[ARBEL_RECV_WQE_ALIGN];
362 } __attribute__ (( packed ));
364 /** An Arbel receive work queue */
365 struct arbel_recv_work_queue {
366 /** Doorbell record number */
367 unsigned int doorbell_idx;
368 /** Work queue entries */
369 union arbel_recv_wqe *wqe;
370 /** Size of work queue */
374 /** Number of special queue pairs */
375 #define ARBEL_NUM_SPECIAL_QPS 4
377 /** Number of queue pairs reserved for the "special QP" block
379 * The special QPs must be in (2n,2n+1) pairs, hence we need to
380 * reserve one extra QP to allow for alignment.
382 #define ARBEL_RSVD_SPECIAL_QPS ( ARBEL_NUM_SPECIAL_QPS + 1 )
384 /** Maximum number of allocatable queue pairs
386 * This is a policy decision, not a device limit.
388 #define ARBEL_MAX_QPS 8
390 /** Queue pair number randomisation mask */
391 #define ARBEL_QPN_RANDOM_MASK 0xfff000
393 /** Arbel queue pair state */
394 enum arbel_queue_pair_state {
401 /** An Arbel queue pair */
402 struct arbel_queue_pair {
403 /** Send work queue */
404 struct arbel_send_work_queue send;
405 /** Receive work queue */
406 struct arbel_recv_work_queue recv;
408 enum arbel_queue_pair_state state;
411 /** Maximum number of allocatable completion queues
413 * This is a policy decision, not a device limit.
415 #define ARBEL_MAX_CQS 8
417 /** An Arbel completion queue */
418 struct arbel_completion_queue {
419 /** Consumer counter doorbell record number */
420 unsigned int ci_doorbell_idx;
421 /** Arm queue doorbell record number */
422 unsigned int arm_doorbell_idx;
423 /** Completion queue entries */
424 union arbelprm_completion_entry *cqe;
425 /** Size of completion queue */
429 /** Maximum number of allocatable event queues
431 * This is a policy decision, not a device limit.
433 #define ARBEL_MAX_EQS 64
435 /** A Arbel event queue */
436 struct arbel_event_queue {
437 /** Event queue entries */
438 union arbelprm_event_entry *eqe;
439 /** Size of event queue */
441 /** Event queue number */
443 /** Next event queue entry index */
444 unsigned long next_idx;
445 /** Doorbell register */
449 /** Number of event queue entries
451 * This is a policy decision.
453 #define ARBEL_NUM_EQES 4
456 /** An Arbel resource bitmask */
457 typedef uint32_t arbel_bitmask_t;
459 /** Size of an Arbel resource bitmask */
460 #define ARBEL_BITMASK_SIZE(max_entries) \
461 ( ( (max_entries) + ( 8 * sizeof ( arbel_bitmask_t ) ) - 1 ) / \
462 ( 8 * sizeof ( arbel_bitmask_t ) ) )
464 /** An Arbel device */
467 struct pci_device *pci;
468 /** PCI configuration registers */
470 /** PCI user Access Region */
472 /** Event queue consumer index doorbells */
473 void *eq_ci_doorbells;
475 /** Command input mailbox */
477 /** Command output mailbox */
480 /** Device open request counter */
481 unsigned int open_count;
485 /** Firmware area in external memory
487 * This is allocated when first needed, and freed only on
488 * final teardown, in order to avoid memory map changes at
491 userptr_t firmware_area;
498 * This is allocated when first needed, and freed only on
499 * final teardown, in order to avoid memory map changes at
503 /** Offset within ICM of doorbell records */
504 size_t db_rec_offset;
505 /** Doorbell records */
506 union arbelprm_doorbell_record *db_rec;
508 struct arbel_event_queue eq;
509 /** Unrestricted LKey
511 * Used to get unrestricted memory access.
515 /** Completion queue in-use bitmask */
516 arbel_bitmask_t cq_inuse[ ARBEL_BITMASK_SIZE ( ARBEL_MAX_CQS ) ];
517 /** Queue pair in-use bitmask */
518 arbel_bitmask_t qp_inuse[ ARBEL_BITMASK_SIZE ( ARBEL_MAX_QPS ) ];
521 struct arbel_dev_limits limits;
522 /** Special QPN base */
523 unsigned long special_qpn_base;
525 unsigned long qpn_base;
527 /** Infiniband devices */
528 struct ib_device *ibdev[ARBEL_NUM_PORTS];
531 /** Global protection domain */
532 #define ARBEL_GLOBAL_PD 0x123456
534 /** Memory key prefix */
535 #define ARBEL_MKEY_PREFIX 0x77000000UL
542 #define ARBEL_HCR_BASE 0x80680
543 #define ARBEL_HCR_REG(x) ( ARBEL_HCR_BASE + 4 * (x) )
544 #define ARBEL_HCR_MAX_WAIT_MS 2000
545 #define ARBEL_MBOX_ALIGN 4096
546 #define ARBEL_MBOX_SIZE 512
548 /* HCA command is split into
551 * bit 12 Input uses mailbox
552 * bit 13 Output uses mailbox
553 * bits 22:14 Input parameter length (in dwords)
554 * bits 31:23 Output parameter length (in dwords)
556 * Encoding the information in this way allows us to cut out several
557 * parameters to the arbel_command() call.
559 #define ARBEL_HCR_IN_MBOX 0x00001000UL
560 #define ARBEL_HCR_OUT_MBOX 0x00002000UL
561 #define ARBEL_HCR_OPCODE( _command ) ( (_command) & 0xfff )
562 #define ARBEL_HCR_IN_LEN( _command ) ( ( (_command) >> 12 ) & 0x7fc )
563 #define ARBEL_HCR_OUT_LEN( _command ) ( ( (_command) >> 21 ) & 0x7fc )
565 /** Build HCR command from component parts */
566 #define ARBEL_HCR_INOUT_CMD( _opcode, _in_mbox, _in_len, \
567 _out_mbox, _out_len ) \
569 ( (_in_mbox) ? ARBEL_HCR_IN_MBOX : 0 ) | \
570 ( ( (_in_len) / 4 ) << 14 ) | \
571 ( (_out_mbox) ? ARBEL_HCR_OUT_MBOX : 0 ) | \
572 ( ( (_out_len) / 4 ) << 23 ) )
574 #define ARBEL_HCR_IN_CMD( _opcode, _in_mbox, _in_len ) \
575 ARBEL_HCR_INOUT_CMD ( _opcode, _in_mbox, _in_len, 0, 0 )
577 #define ARBEL_HCR_OUT_CMD( _opcode, _out_mbox, _out_len ) \
578 ARBEL_HCR_INOUT_CMD ( _opcode, 0, 0, _out_mbox, _out_len )
580 #define ARBEL_HCR_VOID_CMD( _opcode ) \
581 ARBEL_HCR_INOUT_CMD ( _opcode, 0, 0, 0, 0 )
584 * Doorbell record allocation
586 * The doorbell record map looks like:
588 * ARBEL_MAX_CQS * Arm completion queue doorbell
589 * ARBEL_MAX_QPS * Send work request doorbell
591 * ...(empty space)...
592 * ARBEL_MAX_QPS * Receive work request doorbell
593 * ARBEL_MAX_CQS * Completion queue consumer counter update doorbell
596 #define ARBEL_MAX_DOORBELL_RECORDS 512
597 #define ARBEL_GROUP_SEPARATOR_DOORBELL \
598 ( ARBEL_MAX_CQS + ARBEL_RSVD_SPECIAL_QPS + ARBEL_MAX_QPS )
601 * Get arm completion queue doorbell index
603 * @v arbel Arbel device
604 * @v cq Completion queue
605 * @ret doorbell_idx Doorbell index
607 static inline unsigned int
608 arbel_cq_arm_doorbell_idx ( struct arbel *arbel,
609 struct ib_completion_queue *cq ) {
610 return ( cq->cqn - arbel->limits.reserved_cqs );
614 * Get send work request doorbell index
616 * @v arbel Arbel device
618 * @ret doorbell_idx Doorbell index
620 static inline unsigned int
621 arbel_send_doorbell_idx ( struct arbel *arbel, struct ib_queue_pair *qp ) {
622 return ( ARBEL_MAX_CQS +
623 ( ( qp->qpn & ~ARBEL_QPN_RANDOM_MASK ) -
624 arbel->special_qpn_base ) );
628 * Get receive work request doorbell index
630 * @v arbel Arbel device
632 * @ret doorbell_idx Doorbell index
634 static inline unsigned int
635 arbel_recv_doorbell_idx ( struct arbel *arbel, struct ib_queue_pair *qp ) {
636 return ( ARBEL_MAX_DOORBELL_RECORDS - ARBEL_MAX_CQS -
637 ( ( qp->qpn & ~ARBEL_QPN_RANDOM_MASK ) -
638 arbel->special_qpn_base ) - 1 );
642 * Get completion queue consumer counter doorbell index
644 * @v arbel Arbel device
645 * @v cq Completion queue
646 * @ret doorbell_idx Doorbell index
648 static inline unsigned int
649 arbel_cq_ci_doorbell_idx ( struct arbel *arbel,
650 struct ib_completion_queue *cq ) {
651 return ( ARBEL_MAX_DOORBELL_RECORDS -
652 ( cq->cqn - arbel->limits.reserved_cqs ) - 1 );
655 #endif /* _ARBEL_H */