xref: /openbmc/linux/drivers/net/ipa/ipa_cmd.c (revision 28dce2c4)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4  * Copyright (C) 2019-2021 Linaro Ltd.
5  */
6 
7 #include <linux/types.h>
8 #include <linux/device.h>
9 #include <linux/slab.h>
10 #include <linux/bitfield.h>
11 #include <linux/dma-direction.h>
12 
13 #include "gsi.h"
14 #include "gsi_trans.h"
15 #include "ipa.h"
16 #include "ipa_endpoint.h"
17 #include "ipa_table.h"
18 #include "ipa_cmd.h"
19 #include "ipa_mem.h"
20 
21 /**
22  * DOC:  IPA Immediate Commands
23  *
24  * The AP command TX endpoint is used to issue immediate commands to the IPA.
25  * An immediate command is generally used to request the IPA do something
26  * other than data transfer to another endpoint.
27  *
28  * Immediate commands are represented by GSI transactions just like other
29  * transfer requests, represented by a single GSI TRE.  Each immediate
30  * command has a well-defined format, having a payload of a known length.
31  * This allows the transfer element's length field to be used to hold an
32  * immediate command's opcode.  The payload for a command resides in DRAM
33  * and is described by a single scatterlist entry in its transaction.
34  * Commands do not require a transaction completion callback.  To commit
35  * an immediate command transaction, either gsi_trans_commit_wait() or
36  * gsi_trans_commit_wait_timeout() is used.
37  */
38 
39 /* Some commands can wait until indicated pipeline stages are clear */
40 enum pipeline_clear_options {
41 	pipeline_clear_hps		= 0x0,
42 	pipeline_clear_src_grp		= 0x1,
43 	pipeline_clear_full		= 0x2,
44 };
45 
46 /* IPA_CMD_IP_V{4,6}_{FILTER,ROUTING}_INIT */
47 
48 struct ipa_cmd_hw_ip_fltrt_init {
49 	__le64 hash_rules_addr;
50 	__le64 flags;
51 	__le64 nhash_rules_addr;
52 };
53 
54 /* Field masks for ipa_cmd_hw_ip_fltrt_init structure fields */
55 #define IP_FLTRT_FLAGS_HASH_SIZE_FMASK			GENMASK_ULL(11, 0)
56 #define IP_FLTRT_FLAGS_HASH_ADDR_FMASK			GENMASK_ULL(27, 12)
57 #define IP_FLTRT_FLAGS_NHASH_SIZE_FMASK			GENMASK_ULL(39, 28)
58 #define IP_FLTRT_FLAGS_NHASH_ADDR_FMASK			GENMASK_ULL(55, 40)
59 
60 /* IPA_CMD_HDR_INIT_LOCAL */
61 
62 struct ipa_cmd_hw_hdr_init_local {
63 	__le64 hdr_table_addr;
64 	__le32 flags;
65 	__le32 reserved;
66 };
67 
68 /* Field masks for ipa_cmd_hw_hdr_init_local structure fields */
69 #define HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK		GENMASK(11, 0)
70 #define HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK		GENMASK(27, 12)
71 
72 /* IPA_CMD_REGISTER_WRITE */
73 
74 /* For IPA v4.0+, the pipeline clear options are encoded in the opcode */
75 #define REGISTER_WRITE_OPCODE_SKIP_CLEAR_FMASK		GENMASK(8, 8)
76 #define REGISTER_WRITE_OPCODE_CLEAR_OPTION_FMASK	GENMASK(10, 9)
77 
78 struct ipa_cmd_register_write {
79 	__le16 flags;		/* Unused/reserved prior to IPA v4.0 */
80 	__le16 offset;
81 	__le32 value;
82 	__le32 value_mask;
83 	__le32 clear_options;	/* Unused/reserved for IPA v4.0+ */
84 };
85 
86 /* Field masks for ipa_cmd_register_write structure fields */
87 /* The next field is present for IPA v4.0+ */
88 #define REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK		GENMASK(14, 11)
89 /* The next field is not present for IPA v4.0+ */
90 #define REGISTER_WRITE_FLAGS_SKIP_CLEAR_FMASK		GENMASK(15, 15)
91 
92 /* The next field and its values are not present for IPA v4.0+ */
93 #define REGISTER_WRITE_CLEAR_OPTIONS_FMASK		GENMASK(1, 0)
94 
95 /* IPA_CMD_IP_PACKET_INIT */
96 
97 struct ipa_cmd_ip_packet_init {
98 	u8 dest_endpoint;
99 	u8 reserved[7];
100 };
101 
102 /* Field masks for ipa_cmd_ip_packet_init dest_endpoint field */
103 #define IPA_PACKET_INIT_DEST_ENDPOINT_FMASK		GENMASK(4, 0)
104 
105 /* IPA_CMD_DMA_SHARED_MEM */
106 
107 /* For IPA v4.0+, this opcode gets modified with pipeline clear options */
108 
109 #define DMA_SHARED_MEM_OPCODE_SKIP_CLEAR_FMASK		GENMASK(8, 8)
110 #define DMA_SHARED_MEM_OPCODE_CLEAR_OPTION_FMASK	GENMASK(10, 9)
111 
112 struct ipa_cmd_hw_dma_mem_mem {
113 	__le16 clear_after_read; /* 0 or DMA_SHARED_MEM_CLEAR_AFTER_READ */
114 	__le16 size;
115 	__le16 local_addr;
116 	__le16 flags;
117 	__le64 system_addr;
118 };
119 
120 /* Flag allowing atomic clear of target region after reading data (v4.0+)*/
121 #define DMA_SHARED_MEM_CLEAR_AFTER_READ			GENMASK(15, 15)
122 
123 /* Field masks for ipa_cmd_hw_dma_mem_mem structure fields */
124 #define DMA_SHARED_MEM_FLAGS_DIRECTION_FMASK		GENMASK(0, 0)
125 /* The next two fields are not present for IPA v4.0+ */
126 #define DMA_SHARED_MEM_FLAGS_SKIP_CLEAR_FMASK		GENMASK(1, 1)
127 #define DMA_SHARED_MEM_FLAGS_CLEAR_OPTIONS_FMASK	GENMASK(3, 2)
128 
129 /* IPA_CMD_IP_PACKET_TAG_STATUS */
130 
131 struct ipa_cmd_ip_packet_tag_status {
132 	__le64 tag;
133 };
134 
135 #define IP_PACKET_TAG_STATUS_TAG_FMASK			GENMASK_ULL(63, 16)
136 
137 /* Immediate command payload */
138 union ipa_cmd_payload {
139 	struct ipa_cmd_hw_ip_fltrt_init table_init;
140 	struct ipa_cmd_hw_hdr_init_local hdr_init_local;
141 	struct ipa_cmd_register_write register_write;
142 	struct ipa_cmd_ip_packet_init ip_packet_init;
143 	struct ipa_cmd_hw_dma_mem_mem dma_shared_mem;
144 	struct ipa_cmd_ip_packet_tag_status ip_packet_tag_status;
145 };
146 
147 static void ipa_cmd_validate_build(void)
148 {
149 	/* The sizes of a filter and route tables need to fit into fields
150 	 * in the ipa_cmd_hw_ip_fltrt_init structure.  Although hashed tables
151 	 * might not be used, non-hashed and hashed tables have the same
152 	 * maximum size.  IPv4 and IPv6 filter tables have the same number
153 	 * of entries, as and IPv4 and IPv6 route tables have the same number
154 	 * of entries.
155 	 */
156 #define TABLE_SIZE	(TABLE_COUNT_MAX * sizeof(__le64))
157 #define TABLE_COUNT_MAX	max_t(u32, IPA_ROUTE_COUNT_MAX, IPA_FILTER_COUNT_MAX)
158 	BUILD_BUG_ON(TABLE_SIZE > field_max(IP_FLTRT_FLAGS_HASH_SIZE_FMASK));
159 	BUILD_BUG_ON(TABLE_SIZE > field_max(IP_FLTRT_FLAGS_NHASH_SIZE_FMASK));
160 #undef TABLE_COUNT_MAX
161 #undef TABLE_SIZE
162 }
163 
164 #ifdef IPA_VALIDATE
165 
166 /* Validate a memory region holding a table */
167 bool ipa_cmd_table_valid(struct ipa *ipa, const struct ipa_mem *mem,
168 			 bool route, bool ipv6, bool hashed)
169 {
170 	struct device *dev = &ipa->pdev->dev;
171 	u32 offset_max;
172 
173 	offset_max = hashed ? field_max(IP_FLTRT_FLAGS_HASH_ADDR_FMASK)
174 			    : field_max(IP_FLTRT_FLAGS_NHASH_ADDR_FMASK);
175 	if (mem->offset > offset_max ||
176 	    ipa->mem_offset > offset_max - mem->offset) {
177 		dev_err(dev, "IPv%c %s%s table region offset too large\n",
178 			ipv6 ? '6' : '4', hashed ? "hashed " : "",
179 			route ? "route" : "filter");
180 		dev_err(dev, "    (0x%04x + 0x%04x > 0x%04x)\n",
181 			ipa->mem_offset, mem->offset, offset_max);
182 
183 		return false;
184 	}
185 
186 	if (mem->offset > ipa->mem_size ||
187 	    mem->size > ipa->mem_size - mem->offset) {
188 		dev_err(dev, "IPv%c %s%s table region out of range\n",
189 			ipv6 ? '6' : '4', hashed ? "hashed " : "",
190 			route ? "route" : "filter");
191 		dev_err(dev, "    (0x%04x + 0x%04x > 0x%04x)\n",
192 			mem->offset, mem->size, ipa->mem_size);
193 
194 		return false;
195 	}
196 
197 	return true;
198 }
199 
200 /* Validate the memory region that holds headers */
201 static bool ipa_cmd_header_valid(struct ipa *ipa)
202 {
203 	const struct ipa_mem *mem = &ipa->mem[IPA_MEM_MODEM_HEADER];
204 	struct device *dev = &ipa->pdev->dev;
205 	u32 offset_max;
206 	u32 size_max;
207 	u32 size;
208 
209 	/* In ipa_cmd_hdr_init_local_add() we record the offset and size
210 	 * of the header table memory area.  Make sure the offset and size
211 	 * fit in the fields that need to hold them, and that the entire
212 	 * range is within the overall IPA memory range.
213 	 */
214 	offset_max = field_max(HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK);
215 	if (mem->offset > offset_max ||
216 	    ipa->mem_offset > offset_max - mem->offset) {
217 		dev_err(dev, "header table region offset too large\n");
218 		dev_err(dev, "    (0x%04x + 0x%04x > 0x%04x)\n",
219 			ipa->mem_offset, mem->offset, offset_max);
220 
221 		return false;
222 	}
223 
224 	size_max = field_max(HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK);
225 	size = ipa->mem[IPA_MEM_MODEM_HEADER].size;
226 	size += ipa->mem[IPA_MEM_AP_HEADER].size;
227 
228 	if (size > size_max) {
229 		dev_err(dev, "header table region size too large\n");
230 		dev_err(dev, "    (0x%04x > 0x%08x)\n", size, size_max);
231 
232 		return false;
233 	}
234 	if (size > ipa->mem_size || mem->offset > ipa->mem_size - size) {
235 		dev_err(dev, "header table region out of range\n");
236 		dev_err(dev, "    (0x%04x + 0x%04x > 0x%04x)\n",
237 			mem->offset, size, ipa->mem_size);
238 
239 		return false;
240 	}
241 
242 	return true;
243 }
244 
245 /* Indicate whether an offset can be used with a register_write command */
246 static bool ipa_cmd_register_write_offset_valid(struct ipa *ipa,
247 						const char *name, u32 offset)
248 {
249 	struct ipa_cmd_register_write *payload;
250 	struct device *dev = &ipa->pdev->dev;
251 	u32 offset_max;
252 	u32 bit_count;
253 
254 	/* The maximum offset in a register_write immediate command depends
255 	 * on the version of IPA.  A 16 bit offset is always supported,
256 	 * but starting with IPA v4.0 some additional high-order bits are
257 	 * allowed.
258 	 */
259 	bit_count = BITS_PER_BYTE * sizeof(payload->offset);
260 	if (ipa->version >= IPA_VERSION_4_0)
261 		bit_count += hweight32(REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK);
262 	BUILD_BUG_ON(bit_count > 32);
263 	offset_max = ~0U >> (32 - bit_count);
264 
265 	/* Make sure the offset can be represented by the field(s)
266 	 * that holds it.  Also make sure the offset is not outside
267 	 * the overall IPA memory range.
268 	 */
269 	if (offset > offset_max || ipa->mem_offset > offset_max - offset) {
270 		dev_err(dev, "%s offset too large 0x%04x + 0x%04x > 0x%04x)\n",
271 			name, ipa->mem_offset, offset, offset_max);
272 		return false;
273 	}
274 
275 	return true;
276 }
277 
278 /* Check whether offsets passed to register_write are valid */
279 static bool ipa_cmd_register_write_valid(struct ipa *ipa)
280 {
281 	const char *name;
282 	u32 offset;
283 
284 	/* If hashed tables are supported, ensure the hash flush register
285 	 * offset will fit in a register write IPA immediate command.
286 	 */
287 	if (ipa_table_hash_support(ipa)) {
288 		offset = ipa_reg_filt_rout_hash_flush_offset(ipa->version);
289 		name = "filter/route hash flush";
290 		if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
291 			return false;
292 	}
293 
294 	/* Each endpoint can have a status endpoint associated with it,
295 	 * and this is recorded in an endpoint register.  If the modem
296 	 * crashes, we reset the status endpoint for all modem endpoints
297 	 * using a register write IPA immediate command.  Make sure the
298 	 * worst case (highest endpoint number) offset of that endpoint
299 	 * fits in the register write command field(s) that must hold it.
300 	 */
301 	offset = IPA_REG_ENDP_STATUS_N_OFFSET(IPA_ENDPOINT_COUNT - 1);
302 	name = "maximal endpoint status";
303 	if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
304 		return false;
305 
306 	return true;
307 }
308 
309 bool ipa_cmd_data_valid(struct ipa *ipa)
310 {
311 	if (!ipa_cmd_header_valid(ipa))
312 		return false;
313 
314 	if (!ipa_cmd_register_write_valid(ipa))
315 		return false;
316 
317 	return true;
318 }
319 
320 #endif /* IPA_VALIDATE */
321 
322 int ipa_cmd_pool_init(struct gsi_channel *channel, u32 tre_max)
323 {
324 	struct gsi_trans_info *trans_info = &channel->trans_info;
325 	struct device *dev = channel->gsi->dev;
326 	int ret;
327 
328 	/* This is as good a place as any to validate build constants */
329 	ipa_cmd_validate_build();
330 
331 	/* Even though command payloads are allocated one at a time,
332 	 * a single transaction can require up to tlv_count of them,
333 	 * so we treat them as if that many can be allocated at once.
334 	 */
335 	ret = gsi_trans_pool_init_dma(dev, &trans_info->cmd_pool,
336 				      sizeof(union ipa_cmd_payload),
337 				      tre_max, channel->tlv_count);
338 	if (ret)
339 		return ret;
340 
341 	/* Each TRE needs a command info structure */
342 	ret = gsi_trans_pool_init(&trans_info->info_pool,
343 				   sizeof(struct ipa_cmd_info),
344 				   tre_max, channel->tlv_count);
345 	if (ret)
346 		gsi_trans_pool_exit_dma(dev, &trans_info->cmd_pool);
347 
348 	return ret;
349 }
350 
351 void ipa_cmd_pool_exit(struct gsi_channel *channel)
352 {
353 	struct gsi_trans_info *trans_info = &channel->trans_info;
354 	struct device *dev = channel->gsi->dev;
355 
356 	gsi_trans_pool_exit(&trans_info->info_pool);
357 	gsi_trans_pool_exit_dma(dev, &trans_info->cmd_pool);
358 }
359 
360 static union ipa_cmd_payload *
361 ipa_cmd_payload_alloc(struct ipa *ipa, dma_addr_t *addr)
362 {
363 	struct gsi_trans_info *trans_info;
364 	struct ipa_endpoint *endpoint;
365 
366 	endpoint = ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX];
367 	trans_info = &ipa->gsi.channel[endpoint->channel_id].trans_info;
368 
369 	return gsi_trans_pool_alloc_dma(&trans_info->cmd_pool, addr);
370 }
371 
372 /* If hash_size is 0, hash_offset and hash_addr ignored. */
373 void ipa_cmd_table_init_add(struct gsi_trans *trans,
374 			    enum ipa_cmd_opcode opcode, u16 size, u32 offset,
375 			    dma_addr_t addr, u16 hash_size, u32 hash_offset,
376 			    dma_addr_t hash_addr)
377 {
378 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
379 	enum dma_data_direction direction = DMA_TO_DEVICE;
380 	struct ipa_cmd_hw_ip_fltrt_init *payload;
381 	union ipa_cmd_payload *cmd_payload;
382 	dma_addr_t payload_addr;
383 	u64 val;
384 
385 	/* Record the non-hash table offset and size */
386 	offset += ipa->mem_offset;
387 	val = u64_encode_bits(offset, IP_FLTRT_FLAGS_NHASH_ADDR_FMASK);
388 	val |= u64_encode_bits(size, IP_FLTRT_FLAGS_NHASH_SIZE_FMASK);
389 
390 	/* The hash table offset and address are zero if its size is 0 */
391 	if (hash_size) {
392 		/* Record the hash table offset and size */
393 		hash_offset += ipa->mem_offset;
394 		val |= u64_encode_bits(hash_offset,
395 				       IP_FLTRT_FLAGS_HASH_ADDR_FMASK);
396 		val |= u64_encode_bits(hash_size,
397 				       IP_FLTRT_FLAGS_HASH_SIZE_FMASK);
398 	}
399 
400 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
401 	payload = &cmd_payload->table_init;
402 
403 	/* Fill in all offsets and sizes and the non-hash table address */
404 	if (hash_size)
405 		payload->hash_rules_addr = cpu_to_le64(hash_addr);
406 	payload->flags = cpu_to_le64(val);
407 	payload->nhash_rules_addr = cpu_to_le64(addr);
408 
409 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
410 			  direction, opcode);
411 }
412 
413 /* Initialize header space in IPA-local memory */
414 void ipa_cmd_hdr_init_local_add(struct gsi_trans *trans, u32 offset, u16 size,
415 				dma_addr_t addr)
416 {
417 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
418 	enum ipa_cmd_opcode opcode = IPA_CMD_HDR_INIT_LOCAL;
419 	enum dma_data_direction direction = DMA_TO_DEVICE;
420 	struct ipa_cmd_hw_hdr_init_local *payload;
421 	union ipa_cmd_payload *cmd_payload;
422 	dma_addr_t payload_addr;
423 	u32 flags;
424 
425 	offset += ipa->mem_offset;
426 
427 	/* With this command we tell the IPA where in its local memory the
428 	 * header tables reside.  The content of the buffer provided is
429 	 * also written via DMA into that space.  The IPA hardware owns
430 	 * the table, but the AP must initialize it.
431 	 */
432 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
433 	payload = &cmd_payload->hdr_init_local;
434 
435 	payload->hdr_table_addr = cpu_to_le64(addr);
436 	flags = u32_encode_bits(size, HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK);
437 	flags |= u32_encode_bits(offset, HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK);
438 	payload->flags = cpu_to_le32(flags);
439 
440 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
441 			  direction, opcode);
442 }
443 
444 void ipa_cmd_register_write_add(struct gsi_trans *trans, u32 offset, u32 value,
445 				u32 mask, bool clear_full)
446 {
447 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
448 	struct ipa_cmd_register_write *payload;
449 	union ipa_cmd_payload *cmd_payload;
450 	u32 opcode = IPA_CMD_REGISTER_WRITE;
451 	dma_addr_t payload_addr;
452 	u32 clear_option;
453 	u32 options;
454 	u16 flags;
455 
456 	/* pipeline_clear_src_grp is not used */
457 	clear_option = clear_full ? pipeline_clear_full : pipeline_clear_hps;
458 
459 	/* IPA v4.0+ represents the pipeline clear options in the opcode.  It
460 	 * also supports a larger offset by encoding additional high-order
461 	 * bits in the payload flags field.
462 	 */
463 	if (ipa->version >= IPA_VERSION_4_0) {
464 		u16 offset_high;
465 		u32 val;
466 
467 		/* Opcode encodes pipeline clear options */
468 		/* SKIP_CLEAR is always 0 (don't skip pipeline clear) */
469 		val = u16_encode_bits(clear_option,
470 				      REGISTER_WRITE_OPCODE_CLEAR_OPTION_FMASK);
471 		opcode |= val;
472 
473 		/* Extract the high 4 bits from the offset */
474 		offset_high = (u16)u32_get_bits(offset, GENMASK(19, 16));
475 		offset &= (1 << 16) - 1;
476 
477 		/* Extract the top 4 bits and encode it into the flags field */
478 		flags = u16_encode_bits(offset_high,
479 				REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK);
480 		options = 0;	/* reserved */
481 
482 	} else {
483 		flags = 0;	/* SKIP_CLEAR flag is always 0 */
484 		options = u16_encode_bits(clear_option,
485 					  REGISTER_WRITE_CLEAR_OPTIONS_FMASK);
486 	}
487 
488 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
489 	payload = &cmd_payload->register_write;
490 
491 	payload->flags = cpu_to_le16(flags);
492 	payload->offset = cpu_to_le16((u16)offset);
493 	payload->value = cpu_to_le32(value);
494 	payload->value_mask = cpu_to_le32(mask);
495 	payload->clear_options = cpu_to_le32(options);
496 
497 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
498 			  DMA_NONE, opcode);
499 }
500 
501 /* Skip IP packet processing on the next data transfer on a TX channel */
502 static void ipa_cmd_ip_packet_init_add(struct gsi_trans *trans, u8 endpoint_id)
503 {
504 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
505 	enum ipa_cmd_opcode opcode = IPA_CMD_IP_PACKET_INIT;
506 	enum dma_data_direction direction = DMA_TO_DEVICE;
507 	struct ipa_cmd_ip_packet_init *payload;
508 	union ipa_cmd_payload *cmd_payload;
509 	dma_addr_t payload_addr;
510 
511 	/* assert(endpoint_id <
512 		  field_max(IPA_PACKET_INIT_DEST_ENDPOINT_FMASK)); */
513 
514 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
515 	payload = &cmd_payload->ip_packet_init;
516 
517 	payload->dest_endpoint = u8_encode_bits(endpoint_id,
518 					IPA_PACKET_INIT_DEST_ENDPOINT_FMASK);
519 
520 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
521 			  direction, opcode);
522 }
523 
524 /* Use a DMA command to read or write a block of IPA-resident memory */
525 void ipa_cmd_dma_shared_mem_add(struct gsi_trans *trans, u32 offset, u16 size,
526 				dma_addr_t addr, bool toward_ipa)
527 {
528 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
529 	enum ipa_cmd_opcode opcode = IPA_CMD_DMA_SHARED_MEM;
530 	struct ipa_cmd_hw_dma_mem_mem *payload;
531 	union ipa_cmd_payload *cmd_payload;
532 	enum dma_data_direction direction;
533 	dma_addr_t payload_addr;
534 	u16 flags;
535 
536 	/* size and offset must fit in 16 bit fields */
537 	/* assert(size > 0 && size <= U16_MAX); */
538 	/* assert(offset <= U16_MAX && ipa->mem_offset <= U16_MAX - offset); */
539 
540 	offset += ipa->mem_offset;
541 
542 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
543 	payload = &cmd_payload->dma_shared_mem;
544 
545 	/* payload->clear_after_read was reserved prior to IPA v4.0.  It's
546 	 * never needed for current code, so it's 0 regardless of version.
547 	 */
548 	payload->size = cpu_to_le16(size);
549 	payload->local_addr = cpu_to_le16(offset);
550 	/* payload->flags:
551 	 *   direction:		0 = write to IPA, 1 read from IPA
552 	 * Starting at v4.0 these are reserved; either way, all zero:
553 	 *   pipeline clear:	0 = wait for pipeline clear (don't skip)
554 	 *   clear_options:	0 = pipeline_clear_hps
555 	 * Instead, for v4.0+ these are encoded in the opcode.  But again
556 	 * since both values are 0 we won't bother OR'ing them in.
557 	 */
558 	flags = toward_ipa ? 0 : DMA_SHARED_MEM_FLAGS_DIRECTION_FMASK;
559 	payload->flags = cpu_to_le16(flags);
560 	payload->system_addr = cpu_to_le64(addr);
561 
562 	direction = toward_ipa ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
563 
564 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
565 			  direction, opcode);
566 }
567 
568 static void ipa_cmd_ip_tag_status_add(struct gsi_trans *trans)
569 {
570 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
571 	enum ipa_cmd_opcode opcode = IPA_CMD_IP_PACKET_TAG_STATUS;
572 	enum dma_data_direction direction = DMA_TO_DEVICE;
573 	struct ipa_cmd_ip_packet_tag_status *payload;
574 	union ipa_cmd_payload *cmd_payload;
575 	dma_addr_t payload_addr;
576 
577 	/* assert(tag <= field_max(IP_PACKET_TAG_STATUS_TAG_FMASK)); */
578 
579 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
580 	payload = &cmd_payload->ip_packet_tag_status;
581 
582 	payload->tag = le64_encode_bits(0, IP_PACKET_TAG_STATUS_TAG_FMASK);
583 
584 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
585 			  direction, opcode);
586 }
587 
588 /* Issue a small command TX data transfer */
589 static void ipa_cmd_transfer_add(struct gsi_trans *trans)
590 {
591 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
592 	enum dma_data_direction direction = DMA_TO_DEVICE;
593 	enum ipa_cmd_opcode opcode = IPA_CMD_NONE;
594 	union ipa_cmd_payload *payload;
595 	dma_addr_t payload_addr;
596 
597 	/* Just transfer a zero-filled payload structure */
598 	payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
599 
600 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
601 			  direction, opcode);
602 }
603 
604 /* Add immediate commands to a transaction to clear the hardware pipeline */
605 void ipa_cmd_pipeline_clear_add(struct gsi_trans *trans)
606 {
607 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
608 	struct ipa_endpoint *endpoint;
609 
610 	/* This will complete when the transfer is received */
611 	reinit_completion(&ipa->completion);
612 
613 	/* Issue a no-op register write command (mask 0 means no write) */
614 	ipa_cmd_register_write_add(trans, 0, 0, 0, true);
615 
616 	/* Send a data packet through the IPA pipeline.  The packet_init
617 	 * command says to send the next packet directly to the exception
618 	 * endpoint without any other IPA processing.  The tag_status
619 	 * command requests that status be generated on completion of
620 	 * that transfer, and that it will be tagged with a value.
621 	 * Finally, the transfer command sends a small packet of data
622 	 * (instead of a command) using the command endpoint.
623 	 */
624 	endpoint = ipa->name_map[IPA_ENDPOINT_AP_LAN_RX];
625 	ipa_cmd_ip_packet_init_add(trans, endpoint->endpoint_id);
626 	ipa_cmd_ip_tag_status_add(trans);
627 	ipa_cmd_transfer_add(trans);
628 }
629 
630 /* Returns the number of commands required to clear the pipeline */
631 u32 ipa_cmd_pipeline_clear_count(void)
632 {
633 	return 4;
634 }
635 
636 void ipa_cmd_pipeline_clear_wait(struct ipa *ipa)
637 {
638 	wait_for_completion(&ipa->completion);
639 }
640 
641 void ipa_cmd_pipeline_clear(struct ipa *ipa)
642 {
643 	u32 count = ipa_cmd_pipeline_clear_count();
644 	struct gsi_trans *trans;
645 
646 	trans = ipa_cmd_trans_alloc(ipa, count);
647 	if (trans) {
648 		ipa_cmd_pipeline_clear_add(trans);
649 		gsi_trans_commit_wait(trans);
650 		ipa_cmd_pipeline_clear_wait(ipa);
651 	} else {
652 		dev_err(&ipa->pdev->dev,
653 			"error allocating %u entry tag transaction\n", count);
654 	}
655 }
656 
657 static struct ipa_cmd_info *
658 ipa_cmd_info_alloc(struct ipa_endpoint *endpoint, u32 tre_count)
659 {
660 	struct gsi_channel *channel;
661 
662 	channel = &endpoint->ipa->gsi.channel[endpoint->channel_id];
663 
664 	return gsi_trans_pool_alloc(&channel->trans_info.info_pool, tre_count);
665 }
666 
667 /* Allocate a transaction for the command TX endpoint */
668 struct gsi_trans *ipa_cmd_trans_alloc(struct ipa *ipa, u32 tre_count)
669 {
670 	struct ipa_endpoint *endpoint;
671 	struct gsi_trans *trans;
672 
673 	endpoint = ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX];
674 
675 	trans = gsi_channel_trans_alloc(&ipa->gsi, endpoint->channel_id,
676 					tre_count, DMA_NONE);
677 	if (trans)
678 		trans->info = ipa_cmd_info_alloc(endpoint, tre_count);
679 
680 	return trans;
681 }
682