xref: /linux/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c (revision 2305f60b76110cb3e8658a4ae85d1f7eb0c66a5b)
1 /*
2  * Copyright 2016-2018 Advanced Micro Devices, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  */
23 
24 #include <linux/printk.h>
25 #include <linux/slab.h>
26 #include <linux/uaccess.h>
27 #include "kfd_priv.h"
28 #include "kfd_mqd_manager.h"
29 #include "v9_structs.h"
30 #include "gc/gc_9_0_offset.h"
31 #include "gc/gc_9_0_sh_mask.h"
32 #include "sdma0/sdma0_4_0_sh_mask.h"
33 #include "amdgpu_amdkfd.h"
34 
35 static inline struct v9_mqd *get_mqd(void *mqd)
36 {
37 	return (struct v9_mqd *)mqd;
38 }
39 
40 static inline struct v9_sdma_mqd *get_sdma_mqd(void *mqd)
41 {
42 	return (struct v9_sdma_mqd *)mqd;
43 }
44 
45 static void update_cu_mask(struct mqd_manager *mm, void *mqd,
46 			struct queue_properties *q)
47 {
48 	struct v9_mqd *m;
49 	uint32_t se_mask[KFD_MAX_NUM_SE] = {0};
50 
51 	if (q->cu_mask_count == 0)
52 		return;
53 
54 	mqd_symmetrically_map_cu_mask(mm,
55 		q->cu_mask, q->cu_mask_count, se_mask);
56 
57 	m = get_mqd(mqd);
58 	m->compute_static_thread_mgmt_se0 = se_mask[0];
59 	m->compute_static_thread_mgmt_se1 = se_mask[1];
60 	m->compute_static_thread_mgmt_se2 = se_mask[2];
61 	m->compute_static_thread_mgmt_se3 = se_mask[3];
62 	m->compute_static_thread_mgmt_se4 = se_mask[4];
63 	m->compute_static_thread_mgmt_se5 = se_mask[5];
64 	m->compute_static_thread_mgmt_se6 = se_mask[6];
65 	m->compute_static_thread_mgmt_se7 = se_mask[7];
66 
67 	pr_debug("update cu mask to %#x %#x %#x %#x %#x %#x %#x %#x\n",
68 		m->compute_static_thread_mgmt_se0,
69 		m->compute_static_thread_mgmt_se1,
70 		m->compute_static_thread_mgmt_se2,
71 		m->compute_static_thread_mgmt_se3,
72 		m->compute_static_thread_mgmt_se4,
73 		m->compute_static_thread_mgmt_se5,
74 		m->compute_static_thread_mgmt_se6,
75 		m->compute_static_thread_mgmt_se7);
76 }
77 
78 static void set_priority(struct v9_mqd *m, struct queue_properties *q)
79 {
80 	m->cp_hqd_pipe_priority = pipe_priority_map[q->priority];
81 	m->cp_hqd_queue_priority = q->priority;
82 }
83 
84 static struct kfd_mem_obj *allocate_mqd(struct kfd_dev *kfd,
85 		struct queue_properties *q)
86 {
87 	int retval;
88 	struct kfd_mem_obj *mqd_mem_obj = NULL;
89 
90 	/* From V9,  for CWSR, the control stack is located on the next page
91 	 * boundary after the mqd, we will use the gtt allocation function
92 	 * instead of sub-allocation function.
93 	 */
94 	if (kfd->cwsr_enabled && (q->type == KFD_QUEUE_TYPE_COMPUTE)) {
95 		mqd_mem_obj = kzalloc(sizeof(struct kfd_mem_obj), GFP_KERNEL);
96 		if (!mqd_mem_obj)
97 			return NULL;
98 		retval = amdgpu_amdkfd_alloc_gtt_mem(kfd->kgd,
99 			ALIGN(q->ctl_stack_size, PAGE_SIZE) +
100 				ALIGN(sizeof(struct v9_mqd), PAGE_SIZE),
101 			&(mqd_mem_obj->gtt_mem),
102 			&(mqd_mem_obj->gpu_addr),
103 			(void *)&(mqd_mem_obj->cpu_ptr), true);
104 	} else {
105 		retval = kfd_gtt_sa_allocate(kfd, sizeof(struct v9_mqd),
106 				&mqd_mem_obj);
107 	}
108 
109 	if (retval) {
110 		kfree(mqd_mem_obj);
111 		return NULL;
112 	}
113 
114 	return mqd_mem_obj;
115 
116 }
117 
118 static void init_mqd(struct mqd_manager *mm, void **mqd,
119 			struct kfd_mem_obj *mqd_mem_obj, uint64_t *gart_addr,
120 			struct queue_properties *q)
121 {
122 	uint64_t addr;
123 	struct v9_mqd *m;
124 
125 	m = (struct v9_mqd *) mqd_mem_obj->cpu_ptr;
126 	addr = mqd_mem_obj->gpu_addr;
127 
128 	memset(m, 0, sizeof(struct v9_mqd));
129 
130 	m->header = 0xC0310800;
131 	m->compute_pipelinestat_enable = 1;
132 	m->compute_static_thread_mgmt_se0 = 0xFFFFFFFF;
133 	m->compute_static_thread_mgmt_se1 = 0xFFFFFFFF;
134 	m->compute_static_thread_mgmt_se2 = 0xFFFFFFFF;
135 	m->compute_static_thread_mgmt_se3 = 0xFFFFFFFF;
136 	m->compute_static_thread_mgmt_se4 = 0xFFFFFFFF;
137 	m->compute_static_thread_mgmt_se5 = 0xFFFFFFFF;
138 	m->compute_static_thread_mgmt_se6 = 0xFFFFFFFF;
139 	m->compute_static_thread_mgmt_se7 = 0xFFFFFFFF;
140 
141 	m->cp_hqd_persistent_state = CP_HQD_PERSISTENT_STATE__PRELOAD_REQ_MASK |
142 			0x53 << CP_HQD_PERSISTENT_STATE__PRELOAD_SIZE__SHIFT;
143 
144 	m->cp_mqd_control = 1 << CP_MQD_CONTROL__PRIV_STATE__SHIFT;
145 
146 	m->cp_mqd_base_addr_lo        = lower_32_bits(addr);
147 	m->cp_mqd_base_addr_hi        = upper_32_bits(addr);
148 
149 	m->cp_hqd_quantum = 1 << CP_HQD_QUANTUM__QUANTUM_EN__SHIFT |
150 			1 << CP_HQD_QUANTUM__QUANTUM_SCALE__SHIFT |
151 			10 << CP_HQD_QUANTUM__QUANTUM_DURATION__SHIFT;
152 
153 	if (q->format == KFD_QUEUE_FORMAT_AQL) {
154 		m->cp_hqd_aql_control =
155 			1 << CP_HQD_AQL_CONTROL__CONTROL0__SHIFT;
156 	}
157 
158 	if (q->tba_addr) {
159 		m->compute_pgm_rsrc2 |=
160 			(1 << COMPUTE_PGM_RSRC2__TRAP_PRESENT__SHIFT);
161 	}
162 
163 	if (mm->dev->cwsr_enabled && q->ctx_save_restore_area_address) {
164 		m->cp_hqd_persistent_state |=
165 			(1 << CP_HQD_PERSISTENT_STATE__QSWITCH_MODE__SHIFT);
166 		m->cp_hqd_ctx_save_base_addr_lo =
167 			lower_32_bits(q->ctx_save_restore_area_address);
168 		m->cp_hqd_ctx_save_base_addr_hi =
169 			upper_32_bits(q->ctx_save_restore_area_address);
170 		m->cp_hqd_ctx_save_size = q->ctx_save_restore_area_size;
171 		m->cp_hqd_cntl_stack_size = q->ctl_stack_size;
172 		m->cp_hqd_cntl_stack_offset = q->ctl_stack_size;
173 		m->cp_hqd_wg_state_offset = q->ctl_stack_size;
174 	}
175 
176 	*mqd = m;
177 	if (gart_addr)
178 		*gart_addr = addr;
179 	mm->update_mqd(mm, m, q);
180 }
181 
182 static int load_mqd(struct mqd_manager *mm, void *mqd,
183 			uint32_t pipe_id, uint32_t queue_id,
184 			struct queue_properties *p, struct mm_struct *mms)
185 {
186 	/* AQL write pointer counts in 64B packets, PM4/CP counts in dwords. */
187 	uint32_t wptr_shift = (p->format == KFD_QUEUE_FORMAT_AQL ? 4 : 0);
188 
189 	return mm->dev->kfd2kgd->hqd_load(mm->dev->kgd, mqd, pipe_id, queue_id,
190 					  (uint32_t __user *)p->write_ptr,
191 					  wptr_shift, 0, mms);
192 }
193 
194 static int hiq_load_mqd_kiq(struct mqd_manager *mm, void *mqd,
195 			    uint32_t pipe_id, uint32_t queue_id,
196 			    struct queue_properties *p, struct mm_struct *mms)
197 {
198 	return mm->dev->kfd2kgd->hiq_mqd_load(mm->dev->kgd, mqd, pipe_id,
199 					      queue_id, p->doorbell_off);
200 }
201 
202 static void update_mqd(struct mqd_manager *mm, void *mqd,
203 		      struct queue_properties *q)
204 {
205 	struct v9_mqd *m;
206 
207 	m = get_mqd(mqd);
208 
209 	m->cp_hqd_pq_control = 5 << CP_HQD_PQ_CONTROL__RPTR_BLOCK_SIZE__SHIFT;
210 	m->cp_hqd_pq_control |= order_base_2(q->queue_size / 4) - 1;
211 	pr_debug("cp_hqd_pq_control 0x%x\n", m->cp_hqd_pq_control);
212 
213 	m->cp_hqd_pq_base_lo = lower_32_bits((uint64_t)q->queue_address >> 8);
214 	m->cp_hqd_pq_base_hi = upper_32_bits((uint64_t)q->queue_address >> 8);
215 
216 	m->cp_hqd_pq_rptr_report_addr_lo = lower_32_bits((uint64_t)q->read_ptr);
217 	m->cp_hqd_pq_rptr_report_addr_hi = upper_32_bits((uint64_t)q->read_ptr);
218 	m->cp_hqd_pq_wptr_poll_addr_lo = lower_32_bits((uint64_t)q->write_ptr);
219 	m->cp_hqd_pq_wptr_poll_addr_hi = upper_32_bits((uint64_t)q->write_ptr);
220 
221 	m->cp_hqd_pq_doorbell_control =
222 		q->doorbell_off <<
223 			CP_HQD_PQ_DOORBELL_CONTROL__DOORBELL_OFFSET__SHIFT;
224 	pr_debug("cp_hqd_pq_doorbell_control 0x%x\n",
225 			m->cp_hqd_pq_doorbell_control);
226 
227 	m->cp_hqd_ib_control =
228 		3 << CP_HQD_IB_CONTROL__MIN_IB_AVAIL_SIZE__SHIFT |
229 		1 << CP_HQD_IB_CONTROL__IB_EXE_DISABLE__SHIFT;
230 
231 	/*
232 	 * HW does not clamp this field correctly. Maximum EOP queue size
233 	 * is constrained by per-SE EOP done signal count, which is 8-bit.
234 	 * Limit is 0xFF EOP entries (= 0x7F8 dwords). CP will not submit
235 	 * more than (EOP entry count - 1) so a queue size of 0x800 dwords
236 	 * is safe, giving a maximum field value of 0xA.
237 	 */
238 	m->cp_hqd_eop_control = min(0xA,
239 		order_base_2(q->eop_ring_buffer_size / 4) - 1);
240 	m->cp_hqd_eop_base_addr_lo =
241 			lower_32_bits(q->eop_ring_buffer_address >> 8);
242 	m->cp_hqd_eop_base_addr_hi =
243 			upper_32_bits(q->eop_ring_buffer_address >> 8);
244 
245 	m->cp_hqd_iq_timer = 0;
246 
247 	m->cp_hqd_vmid = q->vmid;
248 
249 	if (q->format == KFD_QUEUE_FORMAT_AQL) {
250 		m->cp_hqd_pq_control |= CP_HQD_PQ_CONTROL__NO_UPDATE_RPTR_MASK |
251 				2 << CP_HQD_PQ_CONTROL__SLOT_BASED_WPTR__SHIFT |
252 				1 << CP_HQD_PQ_CONTROL__QUEUE_FULL_EN__SHIFT |
253 				1 << CP_HQD_PQ_CONTROL__WPP_CLAMP_EN__SHIFT;
254 		m->cp_hqd_pq_doorbell_control |= 1 <<
255 			CP_HQD_PQ_DOORBELL_CONTROL__DOORBELL_BIF_DROP__SHIFT;
256 	}
257 	if (mm->dev->cwsr_enabled && q->ctx_save_restore_area_address)
258 		m->cp_hqd_ctx_save_control = 0;
259 
260 	update_cu_mask(mm, mqd, q);
261 	set_priority(m, q);
262 
263 	q->is_active = QUEUE_IS_ACTIVE(*q);
264 }
265 
266 
267 static int destroy_mqd(struct mqd_manager *mm, void *mqd,
268 			enum kfd_preempt_type type,
269 			unsigned int timeout, uint32_t pipe_id,
270 			uint32_t queue_id)
271 {
272 	return mm->dev->kfd2kgd->hqd_destroy
273 		(mm->dev->kgd, mqd, type, timeout,
274 		pipe_id, queue_id);
275 }
276 
277 static void free_mqd(struct mqd_manager *mm, void *mqd,
278 			struct kfd_mem_obj *mqd_mem_obj)
279 {
280 	struct kfd_dev *kfd = mm->dev;
281 
282 	if (mqd_mem_obj->gtt_mem) {
283 		amdgpu_amdkfd_free_gtt_mem(kfd->kgd, mqd_mem_obj->gtt_mem);
284 		kfree(mqd_mem_obj);
285 	} else {
286 		kfd_gtt_sa_free(mm->dev, mqd_mem_obj);
287 	}
288 }
289 
290 static bool is_occupied(struct mqd_manager *mm, void *mqd,
291 			uint64_t queue_address,	uint32_t pipe_id,
292 			uint32_t queue_id)
293 {
294 	return mm->dev->kfd2kgd->hqd_is_occupied(
295 		mm->dev->kgd, queue_address,
296 		pipe_id, queue_id);
297 }
298 
299 static int get_wave_state(struct mqd_manager *mm, void *mqd,
300 			  void __user *ctl_stack,
301 			  u32 *ctl_stack_used_size,
302 			  u32 *save_area_used_size)
303 {
304 	struct v9_mqd *m;
305 
306 	/* Control stack is located one page after MQD. */
307 	void *mqd_ctl_stack = (void *)((uintptr_t)mqd + PAGE_SIZE);
308 
309 	m = get_mqd(mqd);
310 
311 	*ctl_stack_used_size = m->cp_hqd_cntl_stack_size -
312 		m->cp_hqd_cntl_stack_offset;
313 	*save_area_used_size = m->cp_hqd_wg_state_offset -
314 		m->cp_hqd_cntl_stack_size;
315 
316 	if (copy_to_user(ctl_stack, mqd_ctl_stack, m->cp_hqd_cntl_stack_size))
317 		return -EFAULT;
318 
319 	return 0;
320 }
321 
322 static void init_mqd_hiq(struct mqd_manager *mm, void **mqd,
323 			struct kfd_mem_obj *mqd_mem_obj, uint64_t *gart_addr,
324 			struct queue_properties *q)
325 {
326 	struct v9_mqd *m;
327 
328 	init_mqd(mm, mqd, mqd_mem_obj, gart_addr, q);
329 
330 	m = get_mqd(*mqd);
331 
332 	m->cp_hqd_pq_control |= 1 << CP_HQD_PQ_CONTROL__PRIV_STATE__SHIFT |
333 			1 << CP_HQD_PQ_CONTROL__KMD_QUEUE__SHIFT;
334 }
335 
336 static void init_mqd_sdma(struct mqd_manager *mm, void **mqd,
337 		struct kfd_mem_obj *mqd_mem_obj, uint64_t *gart_addr,
338 		struct queue_properties *q)
339 {
340 	struct v9_sdma_mqd *m;
341 
342 	m = (struct v9_sdma_mqd *) mqd_mem_obj->cpu_ptr;
343 
344 	memset(m, 0, sizeof(struct v9_sdma_mqd));
345 
346 	*mqd = m;
347 	if (gart_addr)
348 		*gart_addr = mqd_mem_obj->gpu_addr;
349 
350 	mm->update_mqd(mm, m, q);
351 }
352 
353 static int load_mqd_sdma(struct mqd_manager *mm, void *mqd,
354 		uint32_t pipe_id, uint32_t queue_id,
355 		struct queue_properties *p, struct mm_struct *mms)
356 {
357 	return mm->dev->kfd2kgd->hqd_sdma_load(mm->dev->kgd, mqd,
358 					       (uint32_t __user *)p->write_ptr,
359 					       mms);
360 }
361 
362 #define SDMA_RLC_DUMMY_DEFAULT 0xf
363 
364 static void update_mqd_sdma(struct mqd_manager *mm, void *mqd,
365 		struct queue_properties *q)
366 {
367 	struct v9_sdma_mqd *m;
368 
369 	m = get_sdma_mqd(mqd);
370 	m->sdmax_rlcx_rb_cntl = order_base_2(q->queue_size / 4)
371 		<< SDMA0_RLC0_RB_CNTL__RB_SIZE__SHIFT |
372 		q->vmid << SDMA0_RLC0_RB_CNTL__RB_VMID__SHIFT |
373 		1 << SDMA0_RLC0_RB_CNTL__RPTR_WRITEBACK_ENABLE__SHIFT |
374 		6 << SDMA0_RLC0_RB_CNTL__RPTR_WRITEBACK_TIMER__SHIFT;
375 
376 	m->sdmax_rlcx_rb_base = lower_32_bits(q->queue_address >> 8);
377 	m->sdmax_rlcx_rb_base_hi = upper_32_bits(q->queue_address >> 8);
378 	m->sdmax_rlcx_rb_rptr_addr_lo = lower_32_bits((uint64_t)q->read_ptr);
379 	m->sdmax_rlcx_rb_rptr_addr_hi = upper_32_bits((uint64_t)q->read_ptr);
380 	m->sdmax_rlcx_doorbell_offset =
381 		q->doorbell_off << SDMA0_RLC0_DOORBELL_OFFSET__OFFSET__SHIFT;
382 
383 	m->sdma_engine_id = q->sdma_engine_id;
384 	m->sdma_queue_id = q->sdma_queue_id;
385 	m->sdmax_rlcx_dummy_reg = SDMA_RLC_DUMMY_DEFAULT;
386 
387 	q->is_active = QUEUE_IS_ACTIVE(*q);
388 }
389 
390 /*
391  *  * preempt type here is ignored because there is only one way
392  *  * to preempt sdma queue
393  */
394 static int destroy_mqd_sdma(struct mqd_manager *mm, void *mqd,
395 		enum kfd_preempt_type type,
396 		unsigned int timeout, uint32_t pipe_id,
397 		uint32_t queue_id)
398 {
399 	return mm->dev->kfd2kgd->hqd_sdma_destroy(mm->dev->kgd, mqd, timeout);
400 }
401 
402 static bool is_occupied_sdma(struct mqd_manager *mm, void *mqd,
403 		uint64_t queue_address, uint32_t pipe_id,
404 		uint32_t queue_id)
405 {
406 	return mm->dev->kfd2kgd->hqd_sdma_is_occupied(mm->dev->kgd, mqd);
407 }
408 
409 #if defined(CONFIG_DEBUG_FS)
410 
411 static int debugfs_show_mqd(struct seq_file *m, void *data)
412 {
413 	seq_hex_dump(m, "    ", DUMP_PREFIX_OFFSET, 32, 4,
414 		     data, sizeof(struct v9_mqd), false);
415 	return 0;
416 }
417 
418 static int debugfs_show_mqd_sdma(struct seq_file *m, void *data)
419 {
420 	seq_hex_dump(m, "    ", DUMP_PREFIX_OFFSET, 32, 4,
421 		     data, sizeof(struct v9_sdma_mqd), false);
422 	return 0;
423 }
424 
425 #endif
426 
427 struct mqd_manager *mqd_manager_init_v9(enum KFD_MQD_TYPE type,
428 		struct kfd_dev *dev)
429 {
430 	struct mqd_manager *mqd;
431 
432 	if (WARN_ON(type >= KFD_MQD_TYPE_MAX))
433 		return NULL;
434 
435 	mqd = kzalloc(sizeof(*mqd), GFP_KERNEL);
436 	if (!mqd)
437 		return NULL;
438 
439 	mqd->dev = dev;
440 
441 	switch (type) {
442 	case KFD_MQD_TYPE_CP:
443 		mqd->allocate_mqd = allocate_mqd;
444 		mqd->init_mqd = init_mqd;
445 		mqd->free_mqd = free_mqd;
446 		mqd->load_mqd = load_mqd;
447 		mqd->update_mqd = update_mqd;
448 		mqd->destroy_mqd = destroy_mqd;
449 		mqd->is_occupied = is_occupied;
450 		mqd->get_wave_state = get_wave_state;
451 		mqd->mqd_size = sizeof(struct v9_mqd);
452 #if defined(CONFIG_DEBUG_FS)
453 		mqd->debugfs_show_mqd = debugfs_show_mqd;
454 #endif
455 		break;
456 	case KFD_MQD_TYPE_HIQ:
457 		mqd->allocate_mqd = allocate_hiq_mqd;
458 		mqd->init_mqd = init_mqd_hiq;
459 		mqd->free_mqd = free_mqd_hiq_sdma;
460 		mqd->load_mqd = hiq_load_mqd_kiq;
461 		mqd->update_mqd = update_mqd;
462 		mqd->destroy_mqd = destroy_mqd;
463 		mqd->is_occupied = is_occupied;
464 		mqd->mqd_size = sizeof(struct v9_mqd);
465 #if defined(CONFIG_DEBUG_FS)
466 		mqd->debugfs_show_mqd = debugfs_show_mqd;
467 #endif
468 		break;
469 	case KFD_MQD_TYPE_DIQ:
470 		mqd->allocate_mqd = allocate_mqd;
471 		mqd->init_mqd = init_mqd_hiq;
472 		mqd->free_mqd = free_mqd;
473 		mqd->load_mqd = load_mqd;
474 		mqd->update_mqd = update_mqd;
475 		mqd->destroy_mqd = destroy_mqd;
476 		mqd->is_occupied = is_occupied;
477 		mqd->mqd_size = sizeof(struct v9_mqd);
478 #if defined(CONFIG_DEBUG_FS)
479 		mqd->debugfs_show_mqd = debugfs_show_mqd;
480 #endif
481 		break;
482 	case KFD_MQD_TYPE_SDMA:
483 		mqd->allocate_mqd = allocate_sdma_mqd;
484 		mqd->init_mqd = init_mqd_sdma;
485 		mqd->free_mqd = free_mqd_hiq_sdma;
486 		mqd->load_mqd = load_mqd_sdma;
487 		mqd->update_mqd = update_mqd_sdma;
488 		mqd->destroy_mqd = destroy_mqd_sdma;
489 		mqd->is_occupied = is_occupied_sdma;
490 		mqd->mqd_size = sizeof(struct v9_sdma_mqd);
491 #if defined(CONFIG_DEBUG_FS)
492 		mqd->debugfs_show_mqd = debugfs_show_mqd_sdma;
493 #endif
494 		break;
495 	default:
496 		kfree(mqd);
497 		return NULL;
498 	}
499 
500 	return mqd;
501 }
502