xref: /linux/drivers/mailbox/bcm-flexrm-mailbox.c (revision d7b4e3287ca3a7baf66efd9158498e551a9550da)
1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (C) 2017 Broadcom
3 
4 /*
5  * Broadcom FlexRM Mailbox Driver
6  *
7  * Each Broadcom FlexSparx4 offload engine is implemented as an
8  * extension to Broadcom FlexRM ring manager. The FlexRM ring
9  * manager provides a set of rings which can be used to submit
10  * work to a FlexSparx4 offload engine.
11  *
12  * This driver creates a mailbox controller using a set of FlexRM
13  * rings where each mailbox channel represents a separate FlexRM ring.
14  */
15 
16 #include <asm/barrier.h>
17 #include <asm/byteorder.h>
18 #include <linux/atomic.h>
19 #include <linux/bitmap.h>
20 #include <linux/debugfs.h>
21 #include <linux/delay.h>
22 #include <linux/device.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/dmapool.h>
25 #include <linux/err.h>
26 #include <linux/interrupt.h>
27 #include <linux/kernel.h>
28 #include <linux/mailbox_controller.h>
29 #include <linux/mailbox_client.h>
30 #include <linux/mailbox/brcm-message.h>
31 #include <linux/module.h>
32 #include <linux/msi.h>
33 #include <linux/of_address.h>
34 #include <linux/of_irq.h>
35 #include <linux/platform_device.h>
36 #include <linux/spinlock.h>
37 
38 /* ====== FlexRM register defines ===== */
39 
40 /* FlexRM configuration */
41 #define RING_REGS_SIZE					0x10000
42 #define RING_DESC_SIZE					8
43 #define RING_DESC_INDEX(offset)				\
44 			((offset) / RING_DESC_SIZE)
45 #define RING_DESC_OFFSET(index)				\
46 			((index) * RING_DESC_SIZE)
47 #define RING_MAX_REQ_COUNT				1024
48 #define RING_BD_ALIGN_ORDER				12
49 #define RING_BD_ALIGN_CHECK(addr)			\
50 			(!((addr) & ((0x1 << RING_BD_ALIGN_ORDER) - 1)))
51 #define RING_BD_TOGGLE_INVALID(offset)			\
52 			(((offset) >> RING_BD_ALIGN_ORDER) & 0x1)
53 #define RING_BD_TOGGLE_VALID(offset)			\
54 			(!RING_BD_TOGGLE_INVALID(offset))
55 #define RING_BD_DESC_PER_REQ				32
56 #define RING_BD_DESC_COUNT				\
57 			(RING_MAX_REQ_COUNT * RING_BD_DESC_PER_REQ)
58 #define RING_BD_SIZE					\
59 			(RING_BD_DESC_COUNT * RING_DESC_SIZE)
60 #define RING_CMPL_ALIGN_ORDER				13
61 #define RING_CMPL_DESC_COUNT				RING_MAX_REQ_COUNT
62 #define RING_CMPL_SIZE					\
63 			(RING_CMPL_DESC_COUNT * RING_DESC_SIZE)
64 #define RING_VER_MAGIC					0x76303031
65 
66 /* Per-Ring register offsets */
67 #define RING_VER					0x000
68 #define RING_BD_START_ADDR				0x004
69 #define RING_BD_READ_PTR				0x008
70 #define RING_BD_WRITE_PTR				0x00c
71 #define RING_BD_READ_PTR_DDR_LS				0x010
72 #define RING_BD_READ_PTR_DDR_MS				0x014
73 #define RING_CMPL_START_ADDR				0x018
74 #define RING_CMPL_WRITE_PTR				0x01c
75 #define RING_NUM_REQ_RECV_LS				0x020
76 #define RING_NUM_REQ_RECV_MS				0x024
77 #define RING_NUM_REQ_TRANS_LS				0x028
78 #define RING_NUM_REQ_TRANS_MS				0x02c
79 #define RING_NUM_REQ_OUTSTAND				0x030
80 #define RING_CONTROL					0x034
81 #define RING_FLUSH_DONE					0x038
82 #define RING_MSI_ADDR_LS				0x03c
83 #define RING_MSI_ADDR_MS				0x040
84 #define RING_MSI_CONTROL				0x048
85 #define RING_BD_READ_PTR_DDR_CONTROL			0x04c
86 #define RING_MSI_DATA_VALUE				0x064
87 
88 /* Register RING_BD_START_ADDR fields */
89 #define BD_LAST_UPDATE_HW_SHIFT				28
90 #define BD_LAST_UPDATE_HW_MASK				0x1
91 #define BD_START_ADDR_VALUE(pa)				\
92 	((u32)((((dma_addr_t)(pa)) >> RING_BD_ALIGN_ORDER) & 0x0fffffff))
93 #define BD_START_ADDR_DECODE(val)			\
94 	((dma_addr_t)((val) & 0x0fffffff) << RING_BD_ALIGN_ORDER)
95 
96 /* Register RING_CMPL_START_ADDR fields */
97 #define CMPL_START_ADDR_VALUE(pa)			\
98 	((u32)((((u64)(pa)) >> RING_CMPL_ALIGN_ORDER) & 0x07ffffff))
99 
100 /* Register RING_CONTROL fields */
101 #define CONTROL_MASK_DISABLE_CONTROL			12
102 #define CONTROL_FLUSH_SHIFT				5
103 #define CONTROL_ACTIVE_SHIFT				4
104 #define CONTROL_RATE_ADAPT_MASK				0xf
105 #define CONTROL_RATE_DYNAMIC				0x0
106 #define CONTROL_RATE_FAST				0x8
107 #define CONTROL_RATE_MEDIUM				0x9
108 #define CONTROL_RATE_SLOW				0xa
109 #define CONTROL_RATE_IDLE				0xb
110 
111 /* Register RING_FLUSH_DONE fields */
112 #define FLUSH_DONE_MASK					0x1
113 
114 /* Register RING_MSI_CONTROL fields */
115 #define MSI_TIMER_VAL_SHIFT				16
116 #define MSI_TIMER_VAL_MASK				0xffff
117 #define MSI_ENABLE_SHIFT				15
118 #define MSI_ENABLE_MASK					0x1
119 #define MSI_COUNT_SHIFT					0
120 #define MSI_COUNT_MASK					0x3ff
121 
122 /* Register RING_BD_READ_PTR_DDR_CONTROL fields */
123 #define BD_READ_PTR_DDR_TIMER_VAL_SHIFT			16
124 #define BD_READ_PTR_DDR_TIMER_VAL_MASK			0xffff
125 #define BD_READ_PTR_DDR_ENABLE_SHIFT			15
126 #define BD_READ_PTR_DDR_ENABLE_MASK			0x1
127 
128 /* ====== FlexRM ring descriptor defines ===== */
129 
130 /* Completion descriptor format */
131 #define CMPL_OPAQUE_SHIFT			0
132 #define CMPL_OPAQUE_MASK			0xffff
133 #define CMPL_ENGINE_STATUS_SHIFT		16
134 #define CMPL_ENGINE_STATUS_MASK			0xffff
135 #define CMPL_DME_STATUS_SHIFT			32
136 #define CMPL_DME_STATUS_MASK			0xffff
137 #define CMPL_RM_STATUS_SHIFT			48
138 #define CMPL_RM_STATUS_MASK			0xffff
139 
140 /* Completion DME status code */
141 #define DME_STATUS_MEM_COR_ERR			BIT(0)
142 #define DME_STATUS_MEM_UCOR_ERR			BIT(1)
143 #define DME_STATUS_FIFO_UNDERFLOW		BIT(2)
144 #define DME_STATUS_FIFO_OVERFLOW		BIT(3)
145 #define DME_STATUS_RRESP_ERR			BIT(4)
146 #define DME_STATUS_BRESP_ERR			BIT(5)
147 #define DME_STATUS_ERROR_MASK			(DME_STATUS_MEM_COR_ERR | \
148 						 DME_STATUS_MEM_UCOR_ERR | \
149 						 DME_STATUS_FIFO_UNDERFLOW | \
150 						 DME_STATUS_FIFO_OVERFLOW | \
151 						 DME_STATUS_RRESP_ERR | \
152 						 DME_STATUS_BRESP_ERR)
153 
154 /* Completion RM status code */
155 #define RM_STATUS_CODE_SHIFT			0
156 #define RM_STATUS_CODE_MASK			0x3ff
157 #define RM_STATUS_CODE_GOOD			0x0
158 #define RM_STATUS_CODE_AE_TIMEOUT		0x3ff
159 
160 /* General descriptor format */
161 #define DESC_TYPE_SHIFT				60
162 #define DESC_TYPE_MASK				0xf
163 #define DESC_PAYLOAD_SHIFT			0
164 #define DESC_PAYLOAD_MASK			0x0fffffffffffffff
165 
166 /* Null descriptor format  */
167 #define NULL_TYPE				0
168 #define NULL_TOGGLE_SHIFT			58
169 #define NULL_TOGGLE_MASK			0x1
170 
171 /* Header descriptor format */
172 #define HEADER_TYPE				1
173 #define HEADER_TOGGLE_SHIFT			58
174 #define HEADER_TOGGLE_MASK			0x1
175 #define HEADER_ENDPKT_SHIFT			57
176 #define HEADER_ENDPKT_MASK			0x1
177 #define HEADER_STARTPKT_SHIFT			56
178 #define HEADER_STARTPKT_MASK			0x1
179 #define HEADER_BDCOUNT_SHIFT			36
180 #define HEADER_BDCOUNT_MASK			0x1f
181 #define HEADER_BDCOUNT_MAX			HEADER_BDCOUNT_MASK
182 #define HEADER_FLAGS_SHIFT			16
183 #define HEADER_FLAGS_MASK			0xffff
184 #define HEADER_OPAQUE_SHIFT			0
185 #define HEADER_OPAQUE_MASK			0xffff
186 
187 /* Source (SRC) descriptor format */
188 #define SRC_TYPE				2
189 #define SRC_LENGTH_SHIFT			44
190 #define SRC_LENGTH_MASK				0xffff
191 #define SRC_ADDR_SHIFT				0
192 #define SRC_ADDR_MASK				0x00000fffffffffff
193 
194 /* Destination (DST) descriptor format */
195 #define DST_TYPE				3
196 #define DST_LENGTH_SHIFT			44
197 #define DST_LENGTH_MASK				0xffff
198 #define DST_ADDR_SHIFT				0
199 #define DST_ADDR_MASK				0x00000fffffffffff
200 
201 /* Immediate (IMM) descriptor format */
202 #define IMM_TYPE				4
203 #define IMM_DATA_SHIFT				0
204 #define IMM_DATA_MASK				0x0fffffffffffffff
205 
206 /* Next pointer (NPTR) descriptor format */
207 #define NPTR_TYPE				5
208 #define NPTR_TOGGLE_SHIFT			58
209 #define NPTR_TOGGLE_MASK			0x1
210 #define NPTR_ADDR_SHIFT				0
211 #define NPTR_ADDR_MASK				0x00000fffffffffff
212 
213 /* Mega source (MSRC) descriptor format */
214 #define MSRC_TYPE				6
215 #define MSRC_LENGTH_SHIFT			44
216 #define MSRC_LENGTH_MASK			0xffff
217 #define MSRC_ADDR_SHIFT				0
218 #define MSRC_ADDR_MASK				0x00000fffffffffff
219 
220 /* Mega destination (MDST) descriptor format */
221 #define MDST_TYPE				7
222 #define MDST_LENGTH_SHIFT			44
223 #define MDST_LENGTH_MASK			0xffff
224 #define MDST_ADDR_SHIFT				0
225 #define MDST_ADDR_MASK				0x00000fffffffffff
226 
227 /* Source with tlast (SRCT) descriptor format */
228 #define SRCT_TYPE				8
229 #define SRCT_LENGTH_SHIFT			44
230 #define SRCT_LENGTH_MASK			0xffff
231 #define SRCT_ADDR_SHIFT				0
232 #define SRCT_ADDR_MASK				0x00000fffffffffff
233 
234 /* Destination with tlast (DSTT) descriptor format */
235 #define DSTT_TYPE				9
236 #define DSTT_LENGTH_SHIFT			44
237 #define DSTT_LENGTH_MASK			0xffff
238 #define DSTT_ADDR_SHIFT				0
239 #define DSTT_ADDR_MASK				0x00000fffffffffff
240 
241 /* Immediate with tlast (IMMT) descriptor format */
242 #define IMMT_TYPE				10
243 #define IMMT_DATA_SHIFT				0
244 #define IMMT_DATA_MASK				0x0fffffffffffffff
245 
246 /* Descriptor helper macros */
247 #define DESC_DEC(_d, _s, _m)			(((_d) >> (_s)) & (_m))
248 #define DESC_ENC(_d, _v, _s, _m)		\
249 			do { \
250 				(_d) &= ~((u64)(_m) << (_s)); \
251 				(_d) |= (((u64)(_v) & (_m)) << (_s)); \
252 			} while (0)
253 
254 /* ====== FlexRM data structures ===== */
255 
256 struct flexrm_ring {
257 	/* Unprotected members */
258 	int num;
259 	struct flexrm_mbox *mbox;
260 	void __iomem *regs;
261 	bool irq_requested;
262 	unsigned int irq;
263 	cpumask_t irq_aff_hint;
264 	unsigned int msi_timer_val;
265 	unsigned int msi_count_threshold;
266 	struct brcm_message *requests[RING_MAX_REQ_COUNT];
267 	void *bd_base;
268 	dma_addr_t bd_dma_base;
269 	u32 bd_write_offset;
270 	void *cmpl_base;
271 	dma_addr_t cmpl_dma_base;
272 	/* Atomic stats */
273 	atomic_t msg_send_count;
274 	atomic_t msg_cmpl_count;
275 	/* Protected members */
276 	spinlock_t lock;
277 	DECLARE_BITMAP(requests_bmap, RING_MAX_REQ_COUNT);
278 	u32 cmpl_read_offset;
279 };
280 
281 struct flexrm_mbox {
282 	struct device *dev;
283 	void __iomem *regs;
284 	u32 num_rings;
285 	struct flexrm_ring *rings;
286 	struct dma_pool *bd_pool;
287 	struct dma_pool *cmpl_pool;
288 	struct dentry *root;
289 	struct mbox_controller controller;
290 };
291 
292 /* ====== FlexRM ring descriptor helper routines ===== */
293 
294 static u64 flexrm_read_desc(void *desc_ptr)
295 {
296 	return le64_to_cpu(*((u64 *)desc_ptr));
297 }
298 
299 static void flexrm_write_desc(void *desc_ptr, u64 desc)
300 {
301 	*((u64 *)desc_ptr) = cpu_to_le64(desc);
302 }
303 
304 static u32 flexrm_cmpl_desc_to_reqid(u64 cmpl_desc)
305 {
306 	return (u32)(cmpl_desc & CMPL_OPAQUE_MASK);
307 }
308 
309 static int flexrm_cmpl_desc_to_error(u64 cmpl_desc)
310 {
311 	u32 status;
312 
313 	status = DESC_DEC(cmpl_desc, CMPL_DME_STATUS_SHIFT,
314 			  CMPL_DME_STATUS_MASK);
315 	if (status & DME_STATUS_ERROR_MASK)
316 		return -EIO;
317 
318 	status = DESC_DEC(cmpl_desc, CMPL_RM_STATUS_SHIFT,
319 			  CMPL_RM_STATUS_MASK);
320 	status &= RM_STATUS_CODE_MASK;
321 	if (status == RM_STATUS_CODE_AE_TIMEOUT)
322 		return -ETIMEDOUT;
323 
324 	return 0;
325 }
326 
327 static bool flexrm_is_next_table_desc(void *desc_ptr)
328 {
329 	u64 desc = flexrm_read_desc(desc_ptr);
330 	u32 type = DESC_DEC(desc, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
331 
332 	return (type == NPTR_TYPE) ? true : false;
333 }
334 
335 static u64 flexrm_next_table_desc(u32 toggle, dma_addr_t next_addr)
336 {
337 	u64 desc = 0;
338 
339 	DESC_ENC(desc, NPTR_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
340 	DESC_ENC(desc, toggle, NPTR_TOGGLE_SHIFT, NPTR_TOGGLE_MASK);
341 	DESC_ENC(desc, next_addr, NPTR_ADDR_SHIFT, NPTR_ADDR_MASK);
342 
343 	return desc;
344 }
345 
346 static u64 flexrm_null_desc(u32 toggle)
347 {
348 	u64 desc = 0;
349 
350 	DESC_ENC(desc, NULL_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
351 	DESC_ENC(desc, toggle, NULL_TOGGLE_SHIFT, NULL_TOGGLE_MASK);
352 
353 	return desc;
354 }
355 
356 static u32 flexrm_estimate_header_desc_count(u32 nhcnt)
357 {
358 	u32 hcnt = nhcnt / HEADER_BDCOUNT_MAX;
359 
360 	if (!(nhcnt % HEADER_BDCOUNT_MAX))
361 		hcnt += 1;
362 
363 	return hcnt;
364 }
365 
366 static void flexrm_flip_header_toggle(void *desc_ptr)
367 {
368 	u64 desc = flexrm_read_desc(desc_ptr);
369 
370 	if (desc & ((u64)0x1 << HEADER_TOGGLE_SHIFT))
371 		desc &= ~((u64)0x1 << HEADER_TOGGLE_SHIFT);
372 	else
373 		desc |= ((u64)0x1 << HEADER_TOGGLE_SHIFT);
374 
375 	flexrm_write_desc(desc_ptr, desc);
376 }
377 
378 static u64 flexrm_header_desc(u32 toggle, u32 startpkt, u32 endpkt,
379 			       u32 bdcount, u32 flags, u32 opaque)
380 {
381 	u64 desc = 0;
382 
383 	DESC_ENC(desc, HEADER_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
384 	DESC_ENC(desc, toggle, HEADER_TOGGLE_SHIFT, HEADER_TOGGLE_MASK);
385 	DESC_ENC(desc, startpkt, HEADER_STARTPKT_SHIFT, HEADER_STARTPKT_MASK);
386 	DESC_ENC(desc, endpkt, HEADER_ENDPKT_SHIFT, HEADER_ENDPKT_MASK);
387 	DESC_ENC(desc, bdcount, HEADER_BDCOUNT_SHIFT, HEADER_BDCOUNT_MASK);
388 	DESC_ENC(desc, flags, HEADER_FLAGS_SHIFT, HEADER_FLAGS_MASK);
389 	DESC_ENC(desc, opaque, HEADER_OPAQUE_SHIFT, HEADER_OPAQUE_MASK);
390 
391 	return desc;
392 }
393 
394 static void flexrm_enqueue_desc(u32 nhpos, u32 nhcnt, u32 reqid,
395 				 u64 desc, void **desc_ptr, u32 *toggle,
396 				 void *start_desc, void *end_desc)
397 {
398 	u64 d;
399 	u32 nhavail, _toggle, _startpkt, _endpkt, _bdcount;
400 
401 	/* Sanity check */
402 	if (nhcnt <= nhpos)
403 		return;
404 
405 	/*
406 	 * Each request or packet start with a HEADER descriptor followed
407 	 * by one or more non-HEADER descriptors (SRC, SRCT, MSRC, DST,
408 	 * DSTT, MDST, IMM, and IMMT). The number of non-HEADER descriptors
409 	 * following a HEADER descriptor is represented by BDCOUNT field
410 	 * of HEADER descriptor. The max value of BDCOUNT field is 31 which
411 	 * means we can only have 31 non-HEADER descriptors following one
412 	 * HEADER descriptor.
413 	 *
414 	 * In general use, number of non-HEADER descriptors can easily go
415 	 * beyond 31. To tackle this situation, we have packet (or request)
416 	 * extension bits (STARTPKT and ENDPKT) in the HEADER descriptor.
417 	 *
418 	 * To use packet extension, the first HEADER descriptor of request
419 	 * (or packet) will have STARTPKT=1 and ENDPKT=0. The intermediate
420 	 * HEADER descriptors will have STARTPKT=0 and ENDPKT=0. The last
421 	 * HEADER descriptor will have STARTPKT=0 and ENDPKT=1. Also, the
422 	 * TOGGLE bit of the first HEADER will be set to invalid state to
423 	 * ensure that FlexRM does not start fetching descriptors till all
424 	 * descriptors are enqueued. The user of this function will flip
425 	 * the TOGGLE bit of first HEADER after all descriptors are
426 	 * enqueued.
427 	 */
428 
429 	if ((nhpos % HEADER_BDCOUNT_MAX == 0) && (nhcnt - nhpos)) {
430 		/* Prepare the header descriptor */
431 		nhavail = (nhcnt - nhpos);
432 		_toggle = (nhpos == 0) ? !(*toggle) : (*toggle);
433 		_startpkt = (nhpos == 0) ? 0x1 : 0x0;
434 		_endpkt = (nhavail <= HEADER_BDCOUNT_MAX) ? 0x1 : 0x0;
435 		_bdcount = (nhavail <= HEADER_BDCOUNT_MAX) ?
436 				nhavail : HEADER_BDCOUNT_MAX;
437 		if (nhavail <= HEADER_BDCOUNT_MAX)
438 			_bdcount = nhavail;
439 		else
440 			_bdcount = HEADER_BDCOUNT_MAX;
441 		d = flexrm_header_desc(_toggle, _startpkt, _endpkt,
442 					_bdcount, 0x0, reqid);
443 
444 		/* Write header descriptor */
445 		flexrm_write_desc(*desc_ptr, d);
446 
447 		/* Point to next descriptor */
448 		*desc_ptr += sizeof(desc);
449 		if (*desc_ptr == end_desc)
450 			*desc_ptr = start_desc;
451 
452 		/* Skip next pointer descriptors */
453 		while (flexrm_is_next_table_desc(*desc_ptr)) {
454 			*toggle = (*toggle) ? 0 : 1;
455 			*desc_ptr += sizeof(desc);
456 			if (*desc_ptr == end_desc)
457 				*desc_ptr = start_desc;
458 		}
459 	}
460 
461 	/* Write desired descriptor */
462 	flexrm_write_desc(*desc_ptr, desc);
463 
464 	/* Point to next descriptor */
465 	*desc_ptr += sizeof(desc);
466 	if (*desc_ptr == end_desc)
467 		*desc_ptr = start_desc;
468 
469 	/* Skip next pointer descriptors */
470 	while (flexrm_is_next_table_desc(*desc_ptr)) {
471 		*toggle = (*toggle) ? 0 : 1;
472 		*desc_ptr += sizeof(desc);
473 		if (*desc_ptr == end_desc)
474 			*desc_ptr = start_desc;
475 	}
476 }
477 
478 static u64 flexrm_src_desc(dma_addr_t addr, unsigned int length)
479 {
480 	u64 desc = 0;
481 
482 	DESC_ENC(desc, SRC_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
483 	DESC_ENC(desc, length, SRC_LENGTH_SHIFT, SRC_LENGTH_MASK);
484 	DESC_ENC(desc, addr, SRC_ADDR_SHIFT, SRC_ADDR_MASK);
485 
486 	return desc;
487 }
488 
489 static u64 flexrm_msrc_desc(dma_addr_t addr, unsigned int length_div_16)
490 {
491 	u64 desc = 0;
492 
493 	DESC_ENC(desc, MSRC_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
494 	DESC_ENC(desc, length_div_16, MSRC_LENGTH_SHIFT, MSRC_LENGTH_MASK);
495 	DESC_ENC(desc, addr, MSRC_ADDR_SHIFT, MSRC_ADDR_MASK);
496 
497 	return desc;
498 }
499 
500 static u64 flexrm_dst_desc(dma_addr_t addr, unsigned int length)
501 {
502 	u64 desc = 0;
503 
504 	DESC_ENC(desc, DST_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
505 	DESC_ENC(desc, length, DST_LENGTH_SHIFT, DST_LENGTH_MASK);
506 	DESC_ENC(desc, addr, DST_ADDR_SHIFT, DST_ADDR_MASK);
507 
508 	return desc;
509 }
510 
511 static u64 flexrm_mdst_desc(dma_addr_t addr, unsigned int length_div_16)
512 {
513 	u64 desc = 0;
514 
515 	DESC_ENC(desc, MDST_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
516 	DESC_ENC(desc, length_div_16, MDST_LENGTH_SHIFT, MDST_LENGTH_MASK);
517 	DESC_ENC(desc, addr, MDST_ADDR_SHIFT, MDST_ADDR_MASK);
518 
519 	return desc;
520 }
521 
522 static u64 flexrm_imm_desc(u64 data)
523 {
524 	u64 desc = 0;
525 
526 	DESC_ENC(desc, IMM_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
527 	DESC_ENC(desc, data, IMM_DATA_SHIFT, IMM_DATA_MASK);
528 
529 	return desc;
530 }
531 
532 static u64 flexrm_srct_desc(dma_addr_t addr, unsigned int length)
533 {
534 	u64 desc = 0;
535 
536 	DESC_ENC(desc, SRCT_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
537 	DESC_ENC(desc, length, SRCT_LENGTH_SHIFT, SRCT_LENGTH_MASK);
538 	DESC_ENC(desc, addr, SRCT_ADDR_SHIFT, SRCT_ADDR_MASK);
539 
540 	return desc;
541 }
542 
543 static u64 flexrm_dstt_desc(dma_addr_t addr, unsigned int length)
544 {
545 	u64 desc = 0;
546 
547 	DESC_ENC(desc, DSTT_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
548 	DESC_ENC(desc, length, DSTT_LENGTH_SHIFT, DSTT_LENGTH_MASK);
549 	DESC_ENC(desc, addr, DSTT_ADDR_SHIFT, DSTT_ADDR_MASK);
550 
551 	return desc;
552 }
553 
554 static u64 flexrm_immt_desc(u64 data)
555 {
556 	u64 desc = 0;
557 
558 	DESC_ENC(desc, IMMT_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
559 	DESC_ENC(desc, data, IMMT_DATA_SHIFT, IMMT_DATA_MASK);
560 
561 	return desc;
562 }
563 
564 static bool flexrm_spu_sanity_check(struct brcm_message *msg)
565 {
566 	struct scatterlist *sg;
567 
568 	if (!msg->spu.src || !msg->spu.dst)
569 		return false;
570 	for (sg = msg->spu.src; sg; sg = sg_next(sg)) {
571 		if (sg->length & 0xf) {
572 			if (sg->length > SRC_LENGTH_MASK)
573 				return false;
574 		} else {
575 			if (sg->length > (MSRC_LENGTH_MASK * 16))
576 				return false;
577 		}
578 	}
579 	for (sg = msg->spu.dst; sg; sg = sg_next(sg)) {
580 		if (sg->length & 0xf) {
581 			if (sg->length > DST_LENGTH_MASK)
582 				return false;
583 		} else {
584 			if (sg->length > (MDST_LENGTH_MASK * 16))
585 				return false;
586 		}
587 	}
588 
589 	return true;
590 }
591 
592 static u32 flexrm_spu_estimate_nonheader_desc_count(struct brcm_message *msg)
593 {
594 	u32 cnt = 0;
595 	unsigned int dst_target = 0;
596 	struct scatterlist *src_sg = msg->spu.src, *dst_sg = msg->spu.dst;
597 
598 	while (src_sg || dst_sg) {
599 		if (src_sg) {
600 			cnt++;
601 			dst_target = src_sg->length;
602 			src_sg = sg_next(src_sg);
603 		} else
604 			dst_target = UINT_MAX;
605 
606 		while (dst_target && dst_sg) {
607 			cnt++;
608 			if (dst_sg->length < dst_target)
609 				dst_target -= dst_sg->length;
610 			else
611 				dst_target = 0;
612 			dst_sg = sg_next(dst_sg);
613 		}
614 	}
615 
616 	return cnt;
617 }
618 
619 static int flexrm_spu_dma_map(struct device *dev, struct brcm_message *msg)
620 {
621 	int rc;
622 
623 	rc = dma_map_sg(dev, msg->spu.src, sg_nents(msg->spu.src),
624 			DMA_TO_DEVICE);
625 	if (!rc)
626 		return -EIO;
627 
628 	rc = dma_map_sg(dev, msg->spu.dst, sg_nents(msg->spu.dst),
629 			DMA_FROM_DEVICE);
630 	if (!rc) {
631 		dma_unmap_sg(dev, msg->spu.src, sg_nents(msg->spu.src),
632 			     DMA_TO_DEVICE);
633 		return -EIO;
634 	}
635 
636 	return 0;
637 }
638 
639 static void flexrm_spu_dma_unmap(struct device *dev, struct brcm_message *msg)
640 {
641 	dma_unmap_sg(dev, msg->spu.dst, sg_nents(msg->spu.dst),
642 		     DMA_FROM_DEVICE);
643 	dma_unmap_sg(dev, msg->spu.src, sg_nents(msg->spu.src),
644 		     DMA_TO_DEVICE);
645 }
646 
647 static void *flexrm_spu_write_descs(struct brcm_message *msg, u32 nhcnt,
648 				     u32 reqid, void *desc_ptr, u32 toggle,
649 				     void *start_desc, void *end_desc)
650 {
651 	u64 d;
652 	u32 nhpos = 0;
653 	void *orig_desc_ptr = desc_ptr;
654 	unsigned int dst_target = 0;
655 	struct scatterlist *src_sg = msg->spu.src, *dst_sg = msg->spu.dst;
656 
657 	while (src_sg || dst_sg) {
658 		if (src_sg) {
659 			if (sg_dma_len(src_sg) & 0xf)
660 				d = flexrm_src_desc(sg_dma_address(src_sg),
661 						     sg_dma_len(src_sg));
662 			else
663 				d = flexrm_msrc_desc(sg_dma_address(src_sg),
664 						      sg_dma_len(src_sg)/16);
665 			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
666 					     d, &desc_ptr, &toggle,
667 					     start_desc, end_desc);
668 			nhpos++;
669 			dst_target = sg_dma_len(src_sg);
670 			src_sg = sg_next(src_sg);
671 		} else
672 			dst_target = UINT_MAX;
673 
674 		while (dst_target && dst_sg) {
675 			if (sg_dma_len(dst_sg) & 0xf)
676 				d = flexrm_dst_desc(sg_dma_address(dst_sg),
677 						     sg_dma_len(dst_sg));
678 			else
679 				d = flexrm_mdst_desc(sg_dma_address(dst_sg),
680 						      sg_dma_len(dst_sg)/16);
681 			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
682 					     d, &desc_ptr, &toggle,
683 					     start_desc, end_desc);
684 			nhpos++;
685 			if (sg_dma_len(dst_sg) < dst_target)
686 				dst_target -= sg_dma_len(dst_sg);
687 			else
688 				dst_target = 0;
689 			dst_sg = sg_next(dst_sg);
690 		}
691 	}
692 
693 	/* Null descriptor with invalid toggle bit */
694 	flexrm_write_desc(desc_ptr, flexrm_null_desc(!toggle));
695 
696 	/* Ensure that descriptors have been written to memory */
697 	wmb();
698 
699 	/* Flip toggle bit in header */
700 	flexrm_flip_header_toggle(orig_desc_ptr);
701 
702 	return desc_ptr;
703 }
704 
705 static bool flexrm_sba_sanity_check(struct brcm_message *msg)
706 {
707 	u32 i;
708 
709 	if (!msg->sba.cmds || !msg->sba.cmds_count)
710 		return false;
711 
712 	for (i = 0; i < msg->sba.cmds_count; i++) {
713 		if (((msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_B) ||
714 		     (msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_C)) &&
715 		    (msg->sba.cmds[i].flags & BRCM_SBA_CMD_HAS_OUTPUT))
716 			return false;
717 		if ((msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_B) &&
718 		    (msg->sba.cmds[i].data_len > SRCT_LENGTH_MASK))
719 			return false;
720 		if ((msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_C) &&
721 		    (msg->sba.cmds[i].data_len > SRCT_LENGTH_MASK))
722 			return false;
723 		if ((msg->sba.cmds[i].flags & BRCM_SBA_CMD_HAS_RESP) &&
724 		    (msg->sba.cmds[i].resp_len > DSTT_LENGTH_MASK))
725 			return false;
726 		if ((msg->sba.cmds[i].flags & BRCM_SBA_CMD_HAS_OUTPUT) &&
727 		    (msg->sba.cmds[i].data_len > DSTT_LENGTH_MASK))
728 			return false;
729 	}
730 
731 	return true;
732 }
733 
734 static u32 flexrm_sba_estimate_nonheader_desc_count(struct brcm_message *msg)
735 {
736 	u32 i, cnt;
737 
738 	cnt = 0;
739 	for (i = 0; i < msg->sba.cmds_count; i++) {
740 		cnt++;
741 
742 		if ((msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_B) ||
743 		    (msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_C))
744 			cnt++;
745 
746 		if (msg->sba.cmds[i].flags & BRCM_SBA_CMD_HAS_RESP)
747 			cnt++;
748 
749 		if (msg->sba.cmds[i].flags & BRCM_SBA_CMD_HAS_OUTPUT)
750 			cnt++;
751 	}
752 
753 	return cnt;
754 }
755 
756 static void *flexrm_sba_write_descs(struct brcm_message *msg, u32 nhcnt,
757 				     u32 reqid, void *desc_ptr, u32 toggle,
758 				     void *start_desc, void *end_desc)
759 {
760 	u64 d;
761 	u32 i, nhpos = 0;
762 	struct brcm_sba_command *c;
763 	void *orig_desc_ptr = desc_ptr;
764 
765 	/* Convert SBA commands into descriptors */
766 	for (i = 0; i < msg->sba.cmds_count; i++) {
767 		c = &msg->sba.cmds[i];
768 
769 		if ((c->flags & BRCM_SBA_CMD_HAS_RESP) &&
770 		    (c->flags & BRCM_SBA_CMD_HAS_OUTPUT)) {
771 			/* Destination response descriptor */
772 			d = flexrm_dst_desc(c->resp, c->resp_len);
773 			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
774 					     d, &desc_ptr, &toggle,
775 					     start_desc, end_desc);
776 			nhpos++;
777 		} else if (c->flags & BRCM_SBA_CMD_HAS_RESP) {
778 			/* Destination response with tlast descriptor */
779 			d = flexrm_dstt_desc(c->resp, c->resp_len);
780 			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
781 					     d, &desc_ptr, &toggle,
782 					     start_desc, end_desc);
783 			nhpos++;
784 		}
785 
786 		if (c->flags & BRCM_SBA_CMD_HAS_OUTPUT) {
787 			/* Destination with tlast descriptor */
788 			d = flexrm_dstt_desc(c->data, c->data_len);
789 			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
790 					     d, &desc_ptr, &toggle,
791 					     start_desc, end_desc);
792 			nhpos++;
793 		}
794 
795 		if (c->flags & BRCM_SBA_CMD_TYPE_B) {
796 			/* Command as immediate descriptor */
797 			d = flexrm_imm_desc(c->cmd);
798 			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
799 					     d, &desc_ptr, &toggle,
800 					     start_desc, end_desc);
801 			nhpos++;
802 		} else {
803 			/* Command as immediate descriptor with tlast */
804 			d = flexrm_immt_desc(c->cmd);
805 			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
806 					     d, &desc_ptr, &toggle,
807 					     start_desc, end_desc);
808 			nhpos++;
809 		}
810 
811 		if ((c->flags & BRCM_SBA_CMD_TYPE_B) ||
812 		    (c->flags & BRCM_SBA_CMD_TYPE_C)) {
813 			/* Source with tlast descriptor */
814 			d = flexrm_srct_desc(c->data, c->data_len);
815 			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
816 					     d, &desc_ptr, &toggle,
817 					     start_desc, end_desc);
818 			nhpos++;
819 		}
820 	}
821 
822 	/* Null descriptor with invalid toggle bit */
823 	flexrm_write_desc(desc_ptr, flexrm_null_desc(!toggle));
824 
825 	/* Ensure that descriptors have been written to memory */
826 	wmb();
827 
828 	/* Flip toggle bit in header */
829 	flexrm_flip_header_toggle(orig_desc_ptr);
830 
831 	return desc_ptr;
832 }
833 
834 static bool flexrm_sanity_check(struct brcm_message *msg)
835 {
836 	if (!msg)
837 		return false;
838 
839 	switch (msg->type) {
840 	case BRCM_MESSAGE_SPU:
841 		return flexrm_spu_sanity_check(msg);
842 	case BRCM_MESSAGE_SBA:
843 		return flexrm_sba_sanity_check(msg);
844 	default:
845 		return false;
846 	};
847 }
848 
849 static u32 flexrm_estimate_nonheader_desc_count(struct brcm_message *msg)
850 {
851 	if (!msg)
852 		return 0;
853 
854 	switch (msg->type) {
855 	case BRCM_MESSAGE_SPU:
856 		return flexrm_spu_estimate_nonheader_desc_count(msg);
857 	case BRCM_MESSAGE_SBA:
858 		return flexrm_sba_estimate_nonheader_desc_count(msg);
859 	default:
860 		return 0;
861 	};
862 }
863 
864 static int flexrm_dma_map(struct device *dev, struct brcm_message *msg)
865 {
866 	if (!dev || !msg)
867 		return -EINVAL;
868 
869 	switch (msg->type) {
870 	case BRCM_MESSAGE_SPU:
871 		return flexrm_spu_dma_map(dev, msg);
872 	default:
873 		break;
874 	}
875 
876 	return 0;
877 }
878 
879 static void flexrm_dma_unmap(struct device *dev, struct brcm_message *msg)
880 {
881 	if (!dev || !msg)
882 		return;
883 
884 	switch (msg->type) {
885 	case BRCM_MESSAGE_SPU:
886 		flexrm_spu_dma_unmap(dev, msg);
887 		break;
888 	default:
889 		break;
890 	}
891 }
892 
893 static void *flexrm_write_descs(struct brcm_message *msg, u32 nhcnt,
894 				u32 reqid, void *desc_ptr, u32 toggle,
895 				void *start_desc, void *end_desc)
896 {
897 	if (!msg || !desc_ptr || !start_desc || !end_desc)
898 		return ERR_PTR(-ENOTSUPP);
899 
900 	if ((desc_ptr < start_desc) || (end_desc <= desc_ptr))
901 		return ERR_PTR(-ERANGE);
902 
903 	switch (msg->type) {
904 	case BRCM_MESSAGE_SPU:
905 		return flexrm_spu_write_descs(msg, nhcnt, reqid,
906 					       desc_ptr, toggle,
907 					       start_desc, end_desc);
908 	case BRCM_MESSAGE_SBA:
909 		return flexrm_sba_write_descs(msg, nhcnt, reqid,
910 					       desc_ptr, toggle,
911 					       start_desc, end_desc);
912 	default:
913 		return ERR_PTR(-ENOTSUPP);
914 	};
915 }
916 
917 /* ====== FlexRM driver helper routines ===== */
918 
919 static void flexrm_write_config_in_seqfile(struct flexrm_mbox *mbox,
920 					   struct seq_file *file)
921 {
922 	int i;
923 	const char *state;
924 	struct flexrm_ring *ring;
925 
926 	seq_printf(file, "%-5s %-9s %-18s %-10s %-18s %-10s\n",
927 		   "Ring#", "State", "BD_Addr", "BD_Size",
928 		   "Cmpl_Addr", "Cmpl_Size");
929 
930 	for (i = 0; i < mbox->num_rings; i++) {
931 		ring = &mbox->rings[i];
932 		if (readl(ring->regs + RING_CONTROL) &
933 		    BIT(CONTROL_ACTIVE_SHIFT))
934 			state = "active";
935 		else
936 			state = "inactive";
937 		seq_printf(file,
938 			   "%-5d %-9s 0x%016llx 0x%08x 0x%016llx 0x%08x\n",
939 			   ring->num, state,
940 			   (unsigned long long)ring->bd_dma_base,
941 			   (u32)RING_BD_SIZE,
942 			   (unsigned long long)ring->cmpl_dma_base,
943 			   (u32)RING_CMPL_SIZE);
944 	}
945 }
946 
947 static void flexrm_write_stats_in_seqfile(struct flexrm_mbox *mbox,
948 					  struct seq_file *file)
949 {
950 	int i;
951 	u32 val, bd_read_offset;
952 	struct flexrm_ring *ring;
953 
954 	seq_printf(file, "%-5s %-10s %-10s %-10s %-11s %-11s\n",
955 		   "Ring#", "BD_Read", "BD_Write",
956 		   "Cmpl_Read", "Submitted", "Completed");
957 
958 	for (i = 0; i < mbox->num_rings; i++) {
959 		ring = &mbox->rings[i];
960 		bd_read_offset = readl_relaxed(ring->regs + RING_BD_READ_PTR);
961 		val = readl_relaxed(ring->regs + RING_BD_START_ADDR);
962 		bd_read_offset *= RING_DESC_SIZE;
963 		bd_read_offset += (u32)(BD_START_ADDR_DECODE(val) -
964 					ring->bd_dma_base);
965 		seq_printf(file, "%-5d 0x%08x 0x%08x 0x%08x %-11d %-11d\n",
966 			   ring->num,
967 			   (u32)bd_read_offset,
968 			   (u32)ring->bd_write_offset,
969 			   (u32)ring->cmpl_read_offset,
970 			   (u32)atomic_read(&ring->msg_send_count),
971 			   (u32)atomic_read(&ring->msg_cmpl_count));
972 	}
973 }
974 
975 static int flexrm_new_request(struct flexrm_ring *ring,
976 				struct brcm_message *batch_msg,
977 				struct brcm_message *msg)
978 {
979 	void *next;
980 	unsigned long flags;
981 	u32 val, count, nhcnt;
982 	u32 read_offset, write_offset;
983 	bool exit_cleanup = false;
984 	int ret = 0, reqid;
985 
986 	/* Do sanity check on message */
987 	if (!flexrm_sanity_check(msg))
988 		return -EIO;
989 	msg->error = 0;
990 
991 	/* If no requests possible then save data pointer and goto done. */
992 	spin_lock_irqsave(&ring->lock, flags);
993 	reqid = bitmap_find_free_region(ring->requests_bmap,
994 					RING_MAX_REQ_COUNT, 0);
995 	spin_unlock_irqrestore(&ring->lock, flags);
996 	if (reqid < 0)
997 		return -ENOSPC;
998 	ring->requests[reqid] = msg;
999 
1000 	/* Do DMA mappings for the message */
1001 	ret = flexrm_dma_map(ring->mbox->dev, msg);
1002 	if (ret < 0) {
1003 		ring->requests[reqid] = NULL;
1004 		spin_lock_irqsave(&ring->lock, flags);
1005 		bitmap_release_region(ring->requests_bmap, reqid, 0);
1006 		spin_unlock_irqrestore(&ring->lock, flags);
1007 		return ret;
1008 	}
1009 
1010 	/* Determine current HW BD read offset */
1011 	read_offset = readl_relaxed(ring->regs + RING_BD_READ_PTR);
1012 	val = readl_relaxed(ring->regs + RING_BD_START_ADDR);
1013 	read_offset *= RING_DESC_SIZE;
1014 	read_offset += (u32)(BD_START_ADDR_DECODE(val) - ring->bd_dma_base);
1015 
1016 	/*
1017 	 * Number required descriptors = number of non-header descriptors +
1018 	 *				 number of header descriptors +
1019 	 *				 1x null descriptor
1020 	 */
1021 	nhcnt = flexrm_estimate_nonheader_desc_count(msg);
1022 	count = flexrm_estimate_header_desc_count(nhcnt) + nhcnt + 1;
1023 
1024 	/* Check for available descriptor space. */
1025 	write_offset = ring->bd_write_offset;
1026 	while (count) {
1027 		if (!flexrm_is_next_table_desc(ring->bd_base + write_offset))
1028 			count--;
1029 		write_offset += RING_DESC_SIZE;
1030 		if (write_offset == RING_BD_SIZE)
1031 			write_offset = 0x0;
1032 		if (write_offset == read_offset)
1033 			break;
1034 	}
1035 	if (count) {
1036 		ret = -ENOSPC;
1037 		exit_cleanup = true;
1038 		goto exit;
1039 	}
1040 
1041 	/* Write descriptors to ring */
1042 	next = flexrm_write_descs(msg, nhcnt, reqid,
1043 			ring->bd_base + ring->bd_write_offset,
1044 			RING_BD_TOGGLE_VALID(ring->bd_write_offset),
1045 			ring->bd_base, ring->bd_base + RING_BD_SIZE);
1046 	if (IS_ERR(next)) {
1047 		ret = PTR_ERR(next);
1048 		exit_cleanup = true;
1049 		goto exit;
1050 	}
1051 
1052 	/* Save ring BD write offset */
1053 	ring->bd_write_offset = (unsigned long)(next - ring->bd_base);
1054 
1055 	/* Increment number of messages sent */
1056 	atomic_inc_return(&ring->msg_send_count);
1057 
1058 exit:
1059 	/* Update error status in message */
1060 	msg->error = ret;
1061 
1062 	/* Cleanup if we failed */
1063 	if (exit_cleanup) {
1064 		flexrm_dma_unmap(ring->mbox->dev, msg);
1065 		ring->requests[reqid] = NULL;
1066 		spin_lock_irqsave(&ring->lock, flags);
1067 		bitmap_release_region(ring->requests_bmap, reqid, 0);
1068 		spin_unlock_irqrestore(&ring->lock, flags);
1069 	}
1070 
1071 	return ret;
1072 }
1073 
1074 static int flexrm_process_completions(struct flexrm_ring *ring)
1075 {
1076 	u64 desc;
1077 	int err, count = 0;
1078 	unsigned long flags;
1079 	struct brcm_message *msg = NULL;
1080 	u32 reqid, cmpl_read_offset, cmpl_write_offset;
1081 	struct mbox_chan *chan = &ring->mbox->controller.chans[ring->num];
1082 
1083 	spin_lock_irqsave(&ring->lock, flags);
1084 
1085 	/*
1086 	 * Get current completion read and write offset
1087 	 *
1088 	 * Note: We should read completion write pointer at least once
1089 	 * after we get a MSI interrupt because HW maintains internal
1090 	 * MSI status which will allow next MSI interrupt only after
1091 	 * completion write pointer is read.
1092 	 */
1093 	cmpl_write_offset = readl_relaxed(ring->regs + RING_CMPL_WRITE_PTR);
1094 	cmpl_write_offset *= RING_DESC_SIZE;
1095 	cmpl_read_offset = ring->cmpl_read_offset;
1096 	ring->cmpl_read_offset = cmpl_write_offset;
1097 
1098 	spin_unlock_irqrestore(&ring->lock, flags);
1099 
1100 	/* For each completed request notify mailbox clients */
1101 	reqid = 0;
1102 	while (cmpl_read_offset != cmpl_write_offset) {
1103 		/* Dequeue next completion descriptor */
1104 		desc = *((u64 *)(ring->cmpl_base + cmpl_read_offset));
1105 
1106 		/* Next read offset */
1107 		cmpl_read_offset += RING_DESC_SIZE;
1108 		if (cmpl_read_offset == RING_CMPL_SIZE)
1109 			cmpl_read_offset = 0;
1110 
1111 		/* Decode error from completion descriptor */
1112 		err = flexrm_cmpl_desc_to_error(desc);
1113 		if (err < 0) {
1114 			dev_warn(ring->mbox->dev,
1115 			"ring%d got completion desc=0x%lx with error %d\n",
1116 			ring->num, (unsigned long)desc, err);
1117 		}
1118 
1119 		/* Determine request id from completion descriptor */
1120 		reqid = flexrm_cmpl_desc_to_reqid(desc);
1121 
1122 		/* Determine message pointer based on reqid */
1123 		msg = ring->requests[reqid];
1124 		if (!msg) {
1125 			dev_warn(ring->mbox->dev,
1126 			"ring%d null msg pointer for completion desc=0x%lx\n",
1127 			ring->num, (unsigned long)desc);
1128 			continue;
1129 		}
1130 
1131 		/* Release reqid for recycling */
1132 		ring->requests[reqid] = NULL;
1133 		spin_lock_irqsave(&ring->lock, flags);
1134 		bitmap_release_region(ring->requests_bmap, reqid, 0);
1135 		spin_unlock_irqrestore(&ring->lock, flags);
1136 
1137 		/* Unmap DMA mappings */
1138 		flexrm_dma_unmap(ring->mbox->dev, msg);
1139 
1140 		/* Give-back message to mailbox client */
1141 		msg->error = err;
1142 		mbox_chan_received_data(chan, msg);
1143 
1144 		/* Increment number of completions processed */
1145 		atomic_inc_return(&ring->msg_cmpl_count);
1146 		count++;
1147 	}
1148 
1149 	return count;
1150 }
1151 
1152 /* ====== FlexRM Debugfs callbacks ====== */
1153 
1154 static int flexrm_debugfs_conf_show(struct seq_file *file, void *offset)
1155 {
1156 	struct flexrm_mbox *mbox = dev_get_drvdata(file->private);
1157 
1158 	/* Write config in file */
1159 	flexrm_write_config_in_seqfile(mbox, file);
1160 
1161 	return 0;
1162 }
1163 
1164 static int flexrm_debugfs_stats_show(struct seq_file *file, void *offset)
1165 {
1166 	struct flexrm_mbox *mbox = dev_get_drvdata(file->private);
1167 
1168 	/* Write stats in file */
1169 	flexrm_write_stats_in_seqfile(mbox, file);
1170 
1171 	return 0;
1172 }
1173 
1174 /* ====== FlexRM interrupt handler ===== */
1175 
1176 static irqreturn_t flexrm_irq_event(int irq, void *dev_id)
1177 {
1178 	/* We only have MSI for completions so just wakeup IRQ thread */
1179 	/* Ring related errors will be informed via completion descriptors */
1180 
1181 	return IRQ_WAKE_THREAD;
1182 }
1183 
1184 static irqreturn_t flexrm_irq_thread(int irq, void *dev_id)
1185 {
1186 	flexrm_process_completions(dev_id);
1187 
1188 	return IRQ_HANDLED;
1189 }
1190 
1191 /* ====== FlexRM mailbox callbacks ===== */
1192 
1193 static int flexrm_send_data(struct mbox_chan *chan, void *data)
1194 {
1195 	int i, rc;
1196 	struct flexrm_ring *ring = chan->con_priv;
1197 	struct brcm_message *msg = data;
1198 
1199 	if (msg->type == BRCM_MESSAGE_BATCH) {
1200 		for (i = msg->batch.msgs_queued;
1201 		     i < msg->batch.msgs_count; i++) {
1202 			rc = flexrm_new_request(ring, msg,
1203 						 &msg->batch.msgs[i]);
1204 			if (rc) {
1205 				msg->error = rc;
1206 				return rc;
1207 			}
1208 			msg->batch.msgs_queued++;
1209 		}
1210 		return 0;
1211 	}
1212 
1213 	return flexrm_new_request(ring, NULL, data);
1214 }
1215 
1216 static bool flexrm_peek_data(struct mbox_chan *chan)
1217 {
1218 	int cnt = flexrm_process_completions(chan->con_priv);
1219 
1220 	return (cnt > 0) ? true : false;
1221 }
1222 
1223 static int flexrm_startup(struct mbox_chan *chan)
1224 {
1225 	u64 d;
1226 	u32 val, off;
1227 	int ret = 0;
1228 	dma_addr_t next_addr;
1229 	struct flexrm_ring *ring = chan->con_priv;
1230 
1231 	/* Allocate BD memory */
1232 	ring->bd_base = dma_pool_alloc(ring->mbox->bd_pool,
1233 				       GFP_KERNEL, &ring->bd_dma_base);
1234 	if (!ring->bd_base) {
1235 		dev_err(ring->mbox->dev,
1236 			"can't allocate BD memory for ring%d\n",
1237 			ring->num);
1238 		ret = -ENOMEM;
1239 		goto fail;
1240 	}
1241 
1242 	/* Configure next table pointer entries in BD memory */
1243 	for (off = 0; off < RING_BD_SIZE; off += RING_DESC_SIZE) {
1244 		next_addr = off + RING_DESC_SIZE;
1245 		if (next_addr == RING_BD_SIZE)
1246 			next_addr = 0;
1247 		next_addr += ring->bd_dma_base;
1248 		if (RING_BD_ALIGN_CHECK(next_addr))
1249 			d = flexrm_next_table_desc(RING_BD_TOGGLE_VALID(off),
1250 						    next_addr);
1251 		else
1252 			d = flexrm_null_desc(RING_BD_TOGGLE_INVALID(off));
1253 		flexrm_write_desc(ring->bd_base + off, d);
1254 	}
1255 
1256 	/* Allocate completion memory */
1257 	ring->cmpl_base = dma_pool_zalloc(ring->mbox->cmpl_pool,
1258 					 GFP_KERNEL, &ring->cmpl_dma_base);
1259 	if (!ring->cmpl_base) {
1260 		dev_err(ring->mbox->dev,
1261 			"can't allocate completion memory for ring%d\n",
1262 			ring->num);
1263 		ret = -ENOMEM;
1264 		goto fail_free_bd_memory;
1265 	}
1266 
1267 	/* Request IRQ */
1268 	if (ring->irq == UINT_MAX) {
1269 		dev_err(ring->mbox->dev,
1270 			"ring%d IRQ not available\n", ring->num);
1271 		ret = -ENODEV;
1272 		goto fail_free_cmpl_memory;
1273 	}
1274 	ret = request_threaded_irq(ring->irq,
1275 				   flexrm_irq_event,
1276 				   flexrm_irq_thread,
1277 				   0, dev_name(ring->mbox->dev), ring);
1278 	if (ret) {
1279 		dev_err(ring->mbox->dev,
1280 			"failed to request ring%d IRQ\n", ring->num);
1281 		goto fail_free_cmpl_memory;
1282 	}
1283 	ring->irq_requested = true;
1284 
1285 	/* Set IRQ affinity hint */
1286 	ring->irq_aff_hint = CPU_MASK_NONE;
1287 	val = ring->mbox->num_rings;
1288 	val = (num_online_cpus() < val) ? val / num_online_cpus() : 1;
1289 	cpumask_set_cpu((ring->num / val) % num_online_cpus(),
1290 			&ring->irq_aff_hint);
1291 	ret = irq_update_affinity_hint(ring->irq, &ring->irq_aff_hint);
1292 	if (ret) {
1293 		dev_err(ring->mbox->dev,
1294 			"failed to set IRQ affinity hint for ring%d\n",
1295 			ring->num);
1296 		goto fail_free_irq;
1297 	}
1298 
1299 	/* Disable/inactivate ring */
1300 	writel_relaxed(0x0, ring->regs + RING_CONTROL);
1301 
1302 	/* Program BD start address */
1303 	val = BD_START_ADDR_VALUE(ring->bd_dma_base);
1304 	writel_relaxed(val, ring->regs + RING_BD_START_ADDR);
1305 
1306 	/* BD write pointer will be same as HW write pointer */
1307 	ring->bd_write_offset =
1308 			readl_relaxed(ring->regs + RING_BD_WRITE_PTR);
1309 	ring->bd_write_offset *= RING_DESC_SIZE;
1310 
1311 	/* Program completion start address */
1312 	val = CMPL_START_ADDR_VALUE(ring->cmpl_dma_base);
1313 	writel_relaxed(val, ring->regs + RING_CMPL_START_ADDR);
1314 
1315 	/* Completion read pointer will be same as HW write pointer */
1316 	ring->cmpl_read_offset =
1317 			readl_relaxed(ring->regs + RING_CMPL_WRITE_PTR);
1318 	ring->cmpl_read_offset *= RING_DESC_SIZE;
1319 
1320 	/* Read ring Tx, Rx, and Outstanding counts to clear */
1321 	readl_relaxed(ring->regs + RING_NUM_REQ_RECV_LS);
1322 	readl_relaxed(ring->regs + RING_NUM_REQ_RECV_MS);
1323 	readl_relaxed(ring->regs + RING_NUM_REQ_TRANS_LS);
1324 	readl_relaxed(ring->regs + RING_NUM_REQ_TRANS_MS);
1325 	readl_relaxed(ring->regs + RING_NUM_REQ_OUTSTAND);
1326 
1327 	/* Configure RING_MSI_CONTROL */
1328 	val = 0;
1329 	val |= (ring->msi_timer_val << MSI_TIMER_VAL_SHIFT);
1330 	val |= BIT(MSI_ENABLE_SHIFT);
1331 	val |= (ring->msi_count_threshold & MSI_COUNT_MASK) << MSI_COUNT_SHIFT;
1332 	writel_relaxed(val, ring->regs + RING_MSI_CONTROL);
1333 
1334 	/* Enable/activate ring */
1335 	val = BIT(CONTROL_ACTIVE_SHIFT);
1336 	writel_relaxed(val, ring->regs + RING_CONTROL);
1337 
1338 	/* Reset stats to zero */
1339 	atomic_set(&ring->msg_send_count, 0);
1340 	atomic_set(&ring->msg_cmpl_count, 0);
1341 
1342 	return 0;
1343 
1344 fail_free_irq:
1345 	free_irq(ring->irq, ring);
1346 	ring->irq_requested = false;
1347 fail_free_cmpl_memory:
1348 	dma_pool_free(ring->mbox->cmpl_pool,
1349 		      ring->cmpl_base, ring->cmpl_dma_base);
1350 	ring->cmpl_base = NULL;
1351 fail_free_bd_memory:
1352 	dma_pool_free(ring->mbox->bd_pool,
1353 		      ring->bd_base, ring->bd_dma_base);
1354 	ring->bd_base = NULL;
1355 fail:
1356 	return ret;
1357 }
1358 
1359 static void flexrm_shutdown(struct mbox_chan *chan)
1360 {
1361 	u32 reqid;
1362 	unsigned int timeout;
1363 	struct brcm_message *msg;
1364 	struct flexrm_ring *ring = chan->con_priv;
1365 
1366 	/* Disable/inactivate ring */
1367 	writel_relaxed(0x0, ring->regs + RING_CONTROL);
1368 
1369 	/* Set ring flush state */
1370 	timeout = 1000; /* timeout of 1s */
1371 	writel_relaxed(BIT(CONTROL_FLUSH_SHIFT),
1372 			ring->regs + RING_CONTROL);
1373 	do {
1374 		if (readl_relaxed(ring->regs + RING_FLUSH_DONE) &
1375 		    FLUSH_DONE_MASK)
1376 			break;
1377 		mdelay(1);
1378 	} while (--timeout);
1379 	if (!timeout)
1380 		dev_err(ring->mbox->dev,
1381 			"setting ring%d flush state timedout\n", ring->num);
1382 
1383 	/* Clear ring flush state */
1384 	timeout = 1000; /* timeout of 1s */
1385 	writel_relaxed(0x0, ring->regs + RING_CONTROL);
1386 	do {
1387 		if (!(readl_relaxed(ring->regs + RING_FLUSH_DONE) &
1388 		      FLUSH_DONE_MASK))
1389 			break;
1390 		mdelay(1);
1391 	} while (--timeout);
1392 	if (!timeout)
1393 		dev_err(ring->mbox->dev,
1394 			"clearing ring%d flush state timedout\n", ring->num);
1395 
1396 	/* Abort all in-flight requests */
1397 	for (reqid = 0; reqid < RING_MAX_REQ_COUNT; reqid++) {
1398 		msg = ring->requests[reqid];
1399 		if (!msg)
1400 			continue;
1401 
1402 		/* Release reqid for recycling */
1403 		ring->requests[reqid] = NULL;
1404 
1405 		/* Unmap DMA mappings */
1406 		flexrm_dma_unmap(ring->mbox->dev, msg);
1407 
1408 		/* Give-back message to mailbox client */
1409 		msg->error = -EIO;
1410 		mbox_chan_received_data(chan, msg);
1411 	}
1412 
1413 	/* Clear requests bitmap */
1414 	bitmap_zero(ring->requests_bmap, RING_MAX_REQ_COUNT);
1415 
1416 	/* Release IRQ */
1417 	if (ring->irq_requested) {
1418 		irq_update_affinity_hint(ring->irq, NULL);
1419 		free_irq(ring->irq, ring);
1420 		ring->irq_requested = false;
1421 	}
1422 
1423 	/* Free-up completion descriptor ring */
1424 	if (ring->cmpl_base) {
1425 		dma_pool_free(ring->mbox->cmpl_pool,
1426 			      ring->cmpl_base, ring->cmpl_dma_base);
1427 		ring->cmpl_base = NULL;
1428 	}
1429 
1430 	/* Free-up BD descriptor ring */
1431 	if (ring->bd_base) {
1432 		dma_pool_free(ring->mbox->bd_pool,
1433 			      ring->bd_base, ring->bd_dma_base);
1434 		ring->bd_base = NULL;
1435 	}
1436 }
1437 
1438 static const struct mbox_chan_ops flexrm_mbox_chan_ops = {
1439 	.send_data	= flexrm_send_data,
1440 	.startup	= flexrm_startup,
1441 	.shutdown	= flexrm_shutdown,
1442 	.peek_data	= flexrm_peek_data,
1443 };
1444 
1445 static struct mbox_chan *flexrm_mbox_of_xlate(struct mbox_controller *cntlr,
1446 					const struct of_phandle_args *pa)
1447 {
1448 	struct mbox_chan *chan;
1449 	struct flexrm_ring *ring;
1450 
1451 	if (pa->args_count < 3)
1452 		return ERR_PTR(-EINVAL);
1453 
1454 	if (pa->args[0] >= cntlr->num_chans)
1455 		return ERR_PTR(-ENOENT);
1456 
1457 	if (pa->args[1] > MSI_COUNT_MASK)
1458 		return ERR_PTR(-EINVAL);
1459 
1460 	if (pa->args[2] > MSI_TIMER_VAL_MASK)
1461 		return ERR_PTR(-EINVAL);
1462 
1463 	chan = &cntlr->chans[pa->args[0]];
1464 	ring = chan->con_priv;
1465 	ring->msi_count_threshold = pa->args[1];
1466 	ring->msi_timer_val = pa->args[2];
1467 
1468 	return chan;
1469 }
1470 
1471 /* ====== FlexRM platform driver ===== */
1472 
1473 static void flexrm_mbox_msi_write(struct msi_desc *desc, struct msi_msg *msg)
1474 {
1475 	struct device *dev = msi_desc_to_dev(desc);
1476 	struct flexrm_mbox *mbox = dev_get_drvdata(dev);
1477 	struct flexrm_ring *ring = &mbox->rings[desc->msi_index];
1478 
1479 	/* Configure per-Ring MSI registers */
1480 	writel_relaxed(msg->address_lo, ring->regs + RING_MSI_ADDR_LS);
1481 	writel_relaxed(msg->address_hi, ring->regs + RING_MSI_ADDR_MS);
1482 	writel_relaxed(msg->data, ring->regs + RING_MSI_DATA_VALUE);
1483 }
1484 
1485 static int flexrm_mbox_probe(struct platform_device *pdev)
1486 {
1487 	int index, ret = 0;
1488 	void __iomem *regs;
1489 	void __iomem *regs_end;
1490 	struct resource *iomem;
1491 	struct flexrm_ring *ring;
1492 	struct flexrm_mbox *mbox;
1493 	struct device *dev = &pdev->dev;
1494 
1495 	/* Allocate driver mailbox struct */
1496 	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
1497 	if (!mbox) {
1498 		ret = -ENOMEM;
1499 		goto fail;
1500 	}
1501 	mbox->dev = dev;
1502 	platform_set_drvdata(pdev, mbox);
1503 
1504 	/* Get resource for registers and map registers of all rings */
1505 	mbox->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &iomem);
1506 	if (!iomem || (resource_size(iomem) < RING_REGS_SIZE)) {
1507 		ret = -ENODEV;
1508 		goto fail;
1509 	} else if (IS_ERR(mbox->regs)) {
1510 		ret = PTR_ERR(mbox->regs);
1511 		goto fail;
1512 	}
1513 	regs_end = mbox->regs + resource_size(iomem);
1514 
1515 	/* Scan and count available rings */
1516 	mbox->num_rings = 0;
1517 	for (regs = mbox->regs; regs < regs_end; regs += RING_REGS_SIZE) {
1518 		if (readl_relaxed(regs + RING_VER) == RING_VER_MAGIC)
1519 			mbox->num_rings++;
1520 	}
1521 	if (!mbox->num_rings) {
1522 		ret = -ENODEV;
1523 		goto fail;
1524 	}
1525 
1526 	/* Allocate driver ring structs */
1527 	ring = devm_kcalloc(dev, mbox->num_rings, sizeof(*ring), GFP_KERNEL);
1528 	if (!ring) {
1529 		ret = -ENOMEM;
1530 		goto fail;
1531 	}
1532 	mbox->rings = ring;
1533 
1534 	/* Initialize members of driver ring structs */
1535 	regs = mbox->regs;
1536 	for (index = 0; index < mbox->num_rings; index++) {
1537 		ring = &mbox->rings[index];
1538 		ring->num = index;
1539 		ring->mbox = mbox;
1540 		while ((regs < regs_end) &&
1541 		       (readl_relaxed(regs + RING_VER) != RING_VER_MAGIC))
1542 			regs += RING_REGS_SIZE;
1543 		if (regs_end <= regs) {
1544 			ret = -ENODEV;
1545 			goto fail;
1546 		}
1547 		ring->regs = regs;
1548 		regs += RING_REGS_SIZE;
1549 		ring->irq = UINT_MAX;
1550 		ring->irq_requested = false;
1551 		ring->msi_timer_val = MSI_TIMER_VAL_MASK;
1552 		ring->msi_count_threshold = 0x1;
1553 		memset(ring->requests, 0, sizeof(ring->requests));
1554 		ring->bd_base = NULL;
1555 		ring->bd_dma_base = 0;
1556 		ring->cmpl_base = NULL;
1557 		ring->cmpl_dma_base = 0;
1558 		atomic_set(&ring->msg_send_count, 0);
1559 		atomic_set(&ring->msg_cmpl_count, 0);
1560 		spin_lock_init(&ring->lock);
1561 		bitmap_zero(ring->requests_bmap, RING_MAX_REQ_COUNT);
1562 		ring->cmpl_read_offset = 0;
1563 	}
1564 
1565 	/* FlexRM is capable of 40-bit physical addresses only */
1566 	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(40));
1567 	if (ret) {
1568 		ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
1569 		if (ret)
1570 			goto fail;
1571 	}
1572 
1573 	/* Create DMA pool for ring BD memory */
1574 	mbox->bd_pool = dma_pool_create("bd", dev, RING_BD_SIZE,
1575 					1 << RING_BD_ALIGN_ORDER, 0);
1576 	if (!mbox->bd_pool) {
1577 		ret = -ENOMEM;
1578 		goto fail;
1579 	}
1580 
1581 	/* Create DMA pool for ring completion memory */
1582 	mbox->cmpl_pool = dma_pool_create("cmpl", dev, RING_CMPL_SIZE,
1583 					  1 << RING_CMPL_ALIGN_ORDER, 0);
1584 	if (!mbox->cmpl_pool) {
1585 		ret = -ENOMEM;
1586 		goto fail_destroy_bd_pool;
1587 	}
1588 
1589 	/* Allocate platform MSIs for each ring */
1590 	ret = platform_msi_domain_alloc_irqs(dev, mbox->num_rings,
1591 						flexrm_mbox_msi_write);
1592 	if (ret)
1593 		goto fail_destroy_cmpl_pool;
1594 
1595 	/* Save alloced IRQ numbers for each ring */
1596 	for (index = 0; index < mbox->num_rings; index++)
1597 		mbox->rings[index].irq = msi_get_virq(dev, index);
1598 
1599 	/* Check availability of debugfs */
1600 	if (!debugfs_initialized())
1601 		goto skip_debugfs;
1602 
1603 	/* Create debugfs root entry */
1604 	mbox->root = debugfs_create_dir(dev_name(mbox->dev), NULL);
1605 
1606 	/* Create debugfs config entry */
1607 	debugfs_create_devm_seqfile(mbox->dev, "config", mbox->root,
1608 				    flexrm_debugfs_conf_show);
1609 
1610 	/* Create debugfs stats entry */
1611 	debugfs_create_devm_seqfile(mbox->dev, "stats", mbox->root,
1612 				    flexrm_debugfs_stats_show);
1613 
1614 skip_debugfs:
1615 
1616 	/* Initialize mailbox controller */
1617 	mbox->controller.txdone_irq = false;
1618 	mbox->controller.txdone_poll = false;
1619 	mbox->controller.ops = &flexrm_mbox_chan_ops;
1620 	mbox->controller.dev = dev;
1621 	mbox->controller.num_chans = mbox->num_rings;
1622 	mbox->controller.of_xlate = flexrm_mbox_of_xlate;
1623 	mbox->controller.chans = devm_kcalloc(dev, mbox->num_rings,
1624 				sizeof(*mbox->controller.chans), GFP_KERNEL);
1625 	if (!mbox->controller.chans) {
1626 		ret = -ENOMEM;
1627 		goto fail_free_debugfs_root;
1628 	}
1629 	for (index = 0; index < mbox->num_rings; index++)
1630 		mbox->controller.chans[index].con_priv = &mbox->rings[index];
1631 
1632 	/* Register mailbox controller */
1633 	ret = devm_mbox_controller_register(dev, &mbox->controller);
1634 	if (ret)
1635 		goto fail_free_debugfs_root;
1636 
1637 	dev_info(dev, "registered flexrm mailbox with %d channels\n",
1638 			mbox->controller.num_chans);
1639 
1640 	return 0;
1641 
1642 fail_free_debugfs_root:
1643 	debugfs_remove_recursive(mbox->root);
1644 	platform_msi_domain_free_irqs(dev);
1645 fail_destroy_cmpl_pool:
1646 	dma_pool_destroy(mbox->cmpl_pool);
1647 fail_destroy_bd_pool:
1648 	dma_pool_destroy(mbox->bd_pool);
1649 fail:
1650 	return ret;
1651 }
1652 
1653 static void flexrm_mbox_remove(struct platform_device *pdev)
1654 {
1655 	struct device *dev = &pdev->dev;
1656 	struct flexrm_mbox *mbox = platform_get_drvdata(pdev);
1657 
1658 	debugfs_remove_recursive(mbox->root);
1659 
1660 	platform_msi_domain_free_irqs(dev);
1661 
1662 	dma_pool_destroy(mbox->cmpl_pool);
1663 	dma_pool_destroy(mbox->bd_pool);
1664 }
1665 
1666 static const struct of_device_id flexrm_mbox_of_match[] = {
1667 	{ .compatible = "brcm,iproc-flexrm-mbox", },
1668 	{},
1669 };
1670 MODULE_DEVICE_TABLE(of, flexrm_mbox_of_match);
1671 
1672 static struct platform_driver flexrm_mbox_driver = {
1673 	.driver = {
1674 		.name = "brcm-flexrm-mbox",
1675 		.of_match_table = flexrm_mbox_of_match,
1676 	},
1677 	.probe		= flexrm_mbox_probe,
1678 	.remove_new	= flexrm_mbox_remove,
1679 };
1680 module_platform_driver(flexrm_mbox_driver);
1681 
1682 MODULE_AUTHOR("Anup Patel <anup.patel@broadcom.com>");
1683 MODULE_DESCRIPTION("Broadcom FlexRM mailbox driver");
1684 MODULE_LICENSE("GPL v2");
1685