xref: /openbmc/linux/drivers/net/ipa/ipa_cmd.c (revision 0eb76ba2)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4  * Copyright (C) 2019-2020 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+, this opcode gets modified with pipeline clear options */
75 
76 #define REGISTER_WRITE_OPCODE_SKIP_CLEAR_FMASK		GENMASK(8, 8)
77 #define REGISTER_WRITE_OPCODE_CLEAR_OPTION_FMASK	GENMASK(10, 9)
78 
79 struct ipa_cmd_register_write {
80 	__le16 flags;		/* Unused/reserved for IPA v3.5.1 */
81 	__le16 offset;
82 	__le32 value;
83 	__le32 value_mask;
84 	__le32 clear_options;	/* Unused/reserved for IPA v4.0+ */
85 };
86 
87 /* Field masks for ipa_cmd_register_write structure fields */
88 /* The next field is present for IPA v4.0 and above */
89 #define REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK		GENMASK(14, 11)
90 /* The next field is present for IPA v3.5.1 only */
91 #define REGISTER_WRITE_FLAGS_SKIP_CLEAR_FMASK		GENMASK(15, 15)
92 
93 /* The next field and its values are present for IPA v3.5.1 only */
94 #define REGISTER_WRITE_CLEAR_OPTIONS_FMASK		GENMASK(1, 0)
95 
96 /* IPA_CMD_IP_PACKET_INIT */
97 
98 struct ipa_cmd_ip_packet_init {
99 	u8 dest_endpoint;
100 	u8 reserved[7];
101 };
102 
103 /* Field masks for ipa_cmd_ip_packet_init dest_endpoint field */
104 #define IPA_PACKET_INIT_DEST_ENDPOINT_FMASK		GENMASK(4, 0)
105 
106 /* IPA_CMD_DMA_SHARED_MEM */
107 
108 /* For IPA v4.0+, this opcode gets modified with pipeline clear options */
109 
110 #define DMA_SHARED_MEM_OPCODE_SKIP_CLEAR_FMASK		GENMASK(8, 8)
111 #define DMA_SHARED_MEM_OPCODE_CLEAR_OPTION_FMASK	GENMASK(10, 9)
112 
113 struct ipa_cmd_hw_dma_mem_mem {
114 	__le16 clear_after_read; /* 0 or DMA_SHARED_MEM_CLEAR_AFTER_READ */
115 	__le16 size;
116 	__le16 local_addr;
117 	__le16 flags;
118 	__le64 system_addr;
119 };
120 
121 /* Flag allowing atomic clear of target region after reading data (v4.0+)*/
122 #define DMA_SHARED_MEM_CLEAR_AFTER_READ			GENMASK(15, 15)
123 
124 /* Field masks for ipa_cmd_hw_dma_mem_mem structure fields */
125 #define DMA_SHARED_MEM_FLAGS_DIRECTION_FMASK		GENMASK(0, 0)
126 /* The next two fields are present for IPA v3.5.1 only. */
127 #define DMA_SHARED_MEM_FLAGS_SKIP_CLEAR_FMASK		GENMASK(1, 1)
128 #define DMA_SHARED_MEM_FLAGS_CLEAR_OPTIONS_FMASK	GENMASK(3, 2)
129 
130 /* IPA_CMD_IP_PACKET_TAG_STATUS */
131 
132 struct ipa_cmd_ip_packet_tag_status {
133 	__le64 tag;
134 };
135 
136 #define IP_PACKET_TAG_STATUS_TAG_FMASK			GENMASK_ULL(63, 16)
137 
138 /* Immediate command payload */
139 union ipa_cmd_payload {
140 	struct ipa_cmd_hw_ip_fltrt_init table_init;
141 	struct ipa_cmd_hw_hdr_init_local hdr_init_local;
142 	struct ipa_cmd_register_write register_write;
143 	struct ipa_cmd_ip_packet_init ip_packet_init;
144 	struct ipa_cmd_hw_dma_mem_mem dma_shared_mem;
145 	struct ipa_cmd_ip_packet_tag_status ip_packet_tag_status;
146 };
147 
148 static void ipa_cmd_validate_build(void)
149 {
150 	/* The sizes of a filter and route tables need to fit into fields
151 	 * in the ipa_cmd_hw_ip_fltrt_init structure.  Although hashed tables
152 	 * might not be used, non-hashed and hashed tables have the same
153 	 * maximum size.  IPv4 and IPv6 filter tables have the same number
154 	 * of entries, as and IPv4 and IPv6 route tables have the same number
155 	 * of entries.
156 	 */
157 #define TABLE_SIZE	(TABLE_COUNT_MAX * IPA_TABLE_ENTRY_SIZE)
158 #define TABLE_COUNT_MAX	max_t(u32, IPA_ROUTE_COUNT_MAX, IPA_FILTER_COUNT_MAX)
159 	BUILD_BUG_ON(TABLE_SIZE > field_max(IP_FLTRT_FLAGS_HASH_SIZE_FMASK));
160 	BUILD_BUG_ON(TABLE_SIZE > field_max(IP_FLTRT_FLAGS_NHASH_SIZE_FMASK));
161 #undef TABLE_COUNT_MAX
162 #undef TABLE_SIZE
163 }
164 
165 #ifdef IPA_VALIDATE
166 
167 /* Validate a memory region holding a table */
168 bool ipa_cmd_table_valid(struct ipa *ipa, const struct ipa_mem *mem,
169 			 bool route, bool ipv6, bool hashed)
170 {
171 	struct device *dev = &ipa->pdev->dev;
172 	u32 offset_max;
173 
174 	offset_max = hashed ? field_max(IP_FLTRT_FLAGS_HASH_ADDR_FMASK)
175 			    : field_max(IP_FLTRT_FLAGS_NHASH_ADDR_FMASK);
176 	if (mem->offset > offset_max ||
177 	    ipa->mem_offset > offset_max - mem->offset) {
178 		dev_err(dev, "IPv%c %s%s table region offset too large "
179 			      "(0x%04x + 0x%04x > 0x%04x)\n",
180 			      ipv6 ? '6' : '4', hashed ? "hashed " : "",
181 			      route ? "route" : "filter",
182 			      ipa->mem_offset, mem->offset, offset_max);
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 "
189 			      "(0x%04x + 0x%04x > 0x%04x)\n",
190 			      ipv6 ? '6' : '4', hashed ? "hashed " : "",
191 			      route ? "route" : "filter",
192 			      mem->offset, mem->size, ipa->mem_size);
193 		return false;
194 	}
195 
196 	return true;
197 }
198 
199 /* Validate the memory region that holds headers */
200 static bool ipa_cmd_header_valid(struct ipa *ipa)
201 {
202 	const struct ipa_mem *mem = &ipa->mem[IPA_MEM_MODEM_HEADER];
203 	struct device *dev = &ipa->pdev->dev;
204 	u32 offset_max;
205 	u32 size_max;
206 	u32 size;
207 
208 	offset_max = field_max(HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK);
209 	if (mem->offset > offset_max ||
210 	    ipa->mem_offset > offset_max - mem->offset) {
211 		dev_err(dev, "header table region offset too large "
212 			      "(0x%04x + 0x%04x > 0x%04x)\n",
213 			      ipa->mem_offset + mem->offset, offset_max);
214 		return false;
215 	}
216 
217 	size_max = field_max(HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK);
218 	size = ipa->mem[IPA_MEM_MODEM_HEADER].size;
219 	size += ipa->mem[IPA_MEM_AP_HEADER].size;
220 	if (mem->offset > ipa->mem_size || size > ipa->mem_size - mem->offset) {
221 		dev_err(dev, "header table region out of range "
222 			      "(0x%04x + 0x%04x > 0x%04x)\n",
223 			      mem->offset, size, ipa->mem_size);
224 		return false;
225 	}
226 
227 	return true;
228 }
229 
230 /* Indicate whether an offset can be used with a register_write command */
231 static bool ipa_cmd_register_write_offset_valid(struct ipa *ipa,
232 						const char *name, u32 offset)
233 {
234 	struct ipa_cmd_register_write *payload;
235 	struct device *dev = &ipa->pdev->dev;
236 	u32 offset_max;
237 	u32 bit_count;
238 
239 	/* The maximum offset in a register_write immediate command depends
240 	 * on the version of IPA.  IPA v3.5.1 supports a 16 bit offset, but
241 	 * newer versions allow some additional high-order bits.
242 	 */
243 	bit_count = BITS_PER_BYTE * sizeof(payload->offset);
244 	if (ipa->version != IPA_VERSION_3_5_1)
245 		bit_count += hweight32(REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK);
246 	BUILD_BUG_ON(bit_count > 32);
247 	offset_max = ~0 >> (32 - bit_count);
248 
249 	if (offset > offset_max || ipa->mem_offset > offset_max - offset) {
250 		dev_err(dev, "%s offset too large 0x%04x + 0x%04x > 0x%04x)\n",
251 				ipa->mem_offset + offset, offset_max);
252 		return false;
253 	}
254 
255 	return true;
256 }
257 
258 /* Check whether offsets passed to register_write are valid */
259 static bool ipa_cmd_register_write_valid(struct ipa *ipa)
260 {
261 	const char *name;
262 	u32 offset;
263 
264 	offset = ipa_reg_filt_rout_hash_flush_offset(ipa->version);
265 	name = "filter/route hash flush";
266 	if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
267 		return false;
268 
269 	offset = IPA_REG_ENDP_STATUS_N_OFFSET(IPA_ENDPOINT_COUNT);
270 	name = "maximal endpoint status";
271 	if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
272 		return false;
273 
274 	return true;
275 }
276 
277 bool ipa_cmd_data_valid(struct ipa *ipa)
278 {
279 	if (!ipa_cmd_header_valid(ipa))
280 		return false;
281 
282 	if (!ipa_cmd_register_write_valid(ipa))
283 		return false;
284 
285 	return true;
286 }
287 
288 #endif /* IPA_VALIDATE */
289 
290 int ipa_cmd_pool_init(struct gsi_channel *channel, u32 tre_max)
291 {
292 	struct gsi_trans_info *trans_info = &channel->trans_info;
293 	struct device *dev = channel->gsi->dev;
294 	int ret;
295 
296 	/* This is as good a place as any to validate build constants */
297 	ipa_cmd_validate_build();
298 
299 	/* Even though command payloads are allocated one at a time,
300 	 * a single transaction can require up to tlv_count of them,
301 	 * so we treat them as if that many can be allocated at once.
302 	 */
303 	ret = gsi_trans_pool_init_dma(dev, &trans_info->cmd_pool,
304 				      sizeof(union ipa_cmd_payload),
305 				      tre_max, channel->tlv_count);
306 	if (ret)
307 		return ret;
308 
309 	/* Each TRE needs a command info structure */
310 	ret = gsi_trans_pool_init(&trans_info->info_pool,
311 				   sizeof(struct ipa_cmd_info),
312 				   tre_max, channel->tlv_count);
313 	if (ret)
314 		gsi_trans_pool_exit_dma(dev, &trans_info->cmd_pool);
315 
316 	return ret;
317 }
318 
319 void ipa_cmd_pool_exit(struct gsi_channel *channel)
320 {
321 	struct gsi_trans_info *trans_info = &channel->trans_info;
322 	struct device *dev = channel->gsi->dev;
323 
324 	gsi_trans_pool_exit(&trans_info->info_pool);
325 	gsi_trans_pool_exit_dma(dev, &trans_info->cmd_pool);
326 }
327 
328 static union ipa_cmd_payload *
329 ipa_cmd_payload_alloc(struct ipa *ipa, dma_addr_t *addr)
330 {
331 	struct gsi_trans_info *trans_info;
332 	struct ipa_endpoint *endpoint;
333 
334 	endpoint = ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX];
335 	trans_info = &ipa->gsi.channel[endpoint->channel_id].trans_info;
336 
337 	return gsi_trans_pool_alloc_dma(&trans_info->cmd_pool, addr);
338 }
339 
340 /* If hash_size is 0, hash_offset and hash_addr ignored. */
341 void ipa_cmd_table_init_add(struct gsi_trans *trans,
342 			    enum ipa_cmd_opcode opcode, u16 size, u32 offset,
343 			    dma_addr_t addr, u16 hash_size, u32 hash_offset,
344 			    dma_addr_t hash_addr)
345 {
346 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
347 	enum dma_data_direction direction = DMA_TO_DEVICE;
348 	struct ipa_cmd_hw_ip_fltrt_init *payload;
349 	union ipa_cmd_payload *cmd_payload;
350 	dma_addr_t payload_addr;
351 	u64 val;
352 
353 	/* Record the non-hash table offset and size */
354 	offset += ipa->mem_offset;
355 	val = u64_encode_bits(offset, IP_FLTRT_FLAGS_NHASH_ADDR_FMASK);
356 	val |= u64_encode_bits(size, IP_FLTRT_FLAGS_NHASH_SIZE_FMASK);
357 
358 	/* The hash table offset and address are zero if its size is 0 */
359 	if (hash_size) {
360 		/* Record the hash table offset and size */
361 		hash_offset += ipa->mem_offset;
362 		val |= u64_encode_bits(hash_offset,
363 				       IP_FLTRT_FLAGS_HASH_ADDR_FMASK);
364 		val |= u64_encode_bits(hash_size,
365 				       IP_FLTRT_FLAGS_HASH_SIZE_FMASK);
366 	}
367 
368 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
369 	payload = &cmd_payload->table_init;
370 
371 	/* Fill in all offsets and sizes and the non-hash table address */
372 	if (hash_size)
373 		payload->hash_rules_addr = cpu_to_le64(hash_addr);
374 	payload->flags = cpu_to_le64(val);
375 	payload->nhash_rules_addr = cpu_to_le64(addr);
376 
377 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
378 			  direction, opcode);
379 }
380 
381 /* Initialize header space in IPA-local memory */
382 void ipa_cmd_hdr_init_local_add(struct gsi_trans *trans, u32 offset, u16 size,
383 				dma_addr_t addr)
384 {
385 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
386 	enum ipa_cmd_opcode opcode = IPA_CMD_HDR_INIT_LOCAL;
387 	enum dma_data_direction direction = DMA_TO_DEVICE;
388 	struct ipa_cmd_hw_hdr_init_local *payload;
389 	union ipa_cmd_payload *cmd_payload;
390 	dma_addr_t payload_addr;
391 	u32 flags;
392 
393 	offset += ipa->mem_offset;
394 
395 	/* With this command we tell the IPA where in its local memory the
396 	 * header tables reside.  The content of the buffer provided is
397 	 * also written via DMA into that space.  The IPA hardware owns
398 	 * the table, but the AP must initialize it.
399 	 */
400 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
401 	payload = &cmd_payload->hdr_init_local;
402 
403 	payload->hdr_table_addr = cpu_to_le64(addr);
404 	flags = u32_encode_bits(size, HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK);
405 	flags |= u32_encode_bits(offset, HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK);
406 	payload->flags = cpu_to_le32(flags);
407 
408 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
409 			  direction, opcode);
410 }
411 
412 void ipa_cmd_register_write_add(struct gsi_trans *trans, u32 offset, u32 value,
413 				u32 mask, bool clear_full)
414 {
415 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
416 	struct ipa_cmd_register_write *payload;
417 	union ipa_cmd_payload *cmd_payload;
418 	u32 opcode = IPA_CMD_REGISTER_WRITE;
419 	dma_addr_t payload_addr;
420 	u32 clear_option;
421 	u32 options;
422 	u16 flags;
423 
424 	/* pipeline_clear_src_grp is not used */
425 	clear_option = clear_full ? pipeline_clear_full : pipeline_clear_hps;
426 
427 	if (ipa->version != IPA_VERSION_3_5_1) {
428 		u16 offset_high;
429 		u32 val;
430 
431 		/* Opcode encodes pipeline clear options */
432 		/* SKIP_CLEAR is always 0 (don't skip pipeline clear) */
433 		val = u16_encode_bits(clear_option,
434 				      REGISTER_WRITE_OPCODE_CLEAR_OPTION_FMASK);
435 		opcode |= val;
436 
437 		/* Extract the high 4 bits from the offset */
438 		offset_high = (u16)u32_get_bits(offset, GENMASK(19, 16));
439 		offset &= (1 << 16) - 1;
440 
441 		/* Extract the top 4 bits and encode it into the flags field */
442 		flags = u16_encode_bits(offset_high,
443 				REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK);
444 		options = 0;	/* reserved */
445 
446 	} else {
447 		flags = 0;	/* SKIP_CLEAR flag is always 0 */
448 		options = u16_encode_bits(clear_option,
449 					  REGISTER_WRITE_CLEAR_OPTIONS_FMASK);
450 	}
451 
452 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
453 	payload = &cmd_payload->register_write;
454 
455 	payload->flags = cpu_to_le16(flags);
456 	payload->offset = cpu_to_le16((u16)offset);
457 	payload->value = cpu_to_le32(value);
458 	payload->value_mask = cpu_to_le32(mask);
459 	payload->clear_options = cpu_to_le32(options);
460 
461 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
462 			  DMA_NONE, opcode);
463 }
464 
465 /* Skip IP packet processing on the next data transfer on a TX channel */
466 static void ipa_cmd_ip_packet_init_add(struct gsi_trans *trans, u8 endpoint_id)
467 {
468 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
469 	enum ipa_cmd_opcode opcode = IPA_CMD_IP_PACKET_INIT;
470 	enum dma_data_direction direction = DMA_TO_DEVICE;
471 	struct ipa_cmd_ip_packet_init *payload;
472 	union ipa_cmd_payload *cmd_payload;
473 	dma_addr_t payload_addr;
474 
475 	/* assert(endpoint_id <
476 		  field_max(IPA_PACKET_INIT_DEST_ENDPOINT_FMASK)); */
477 
478 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
479 	payload = &cmd_payload->ip_packet_init;
480 
481 	payload->dest_endpoint = u8_encode_bits(endpoint_id,
482 					IPA_PACKET_INIT_DEST_ENDPOINT_FMASK);
483 
484 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
485 			  direction, opcode);
486 }
487 
488 /* Use a DMA command to read or write a block of IPA-resident memory */
489 void ipa_cmd_dma_shared_mem_add(struct gsi_trans *trans, u32 offset, u16 size,
490 				dma_addr_t addr, bool toward_ipa)
491 {
492 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
493 	enum ipa_cmd_opcode opcode = IPA_CMD_DMA_SHARED_MEM;
494 	struct ipa_cmd_hw_dma_mem_mem *payload;
495 	union ipa_cmd_payload *cmd_payload;
496 	enum dma_data_direction direction;
497 	dma_addr_t payload_addr;
498 	u16 flags;
499 
500 	/* size and offset must fit in 16 bit fields */
501 	/* assert(size > 0 && size <= U16_MAX); */
502 	/* assert(offset <= U16_MAX && ipa->mem_offset <= U16_MAX - offset); */
503 
504 	offset += ipa->mem_offset;
505 
506 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
507 	payload = &cmd_payload->dma_shared_mem;
508 
509 	/* payload->clear_after_read was reserved prior to IPA v4.0.  It's
510 	 * never needed for current code, so it's 0 regardless of version.
511 	 */
512 	payload->size = cpu_to_le16(size);
513 	payload->local_addr = cpu_to_le16(offset);
514 	/* payload->flags:
515 	 *   direction:		0 = write to IPA, 1 read from IPA
516 	 * Starting at v4.0 these are reserved; either way, all zero:
517 	 *   pipeline clear:	0 = wait for pipeline clear (don't skip)
518 	 *   clear_options:	0 = pipeline_clear_hps
519 	 * Instead, for v4.0+ these are encoded in the opcode.  But again
520 	 * since both values are 0 we won't bother OR'ing them in.
521 	 */
522 	flags = toward_ipa ? 0 : DMA_SHARED_MEM_FLAGS_DIRECTION_FMASK;
523 	payload->flags = cpu_to_le16(flags);
524 	payload->system_addr = cpu_to_le64(addr);
525 
526 	direction = toward_ipa ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
527 
528 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
529 			  direction, opcode);
530 }
531 
532 static void ipa_cmd_ip_tag_status_add(struct gsi_trans *trans, u64 tag)
533 {
534 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
535 	enum ipa_cmd_opcode opcode = IPA_CMD_IP_PACKET_TAG_STATUS;
536 	enum dma_data_direction direction = DMA_TO_DEVICE;
537 	struct ipa_cmd_ip_packet_tag_status *payload;
538 	union ipa_cmd_payload *cmd_payload;
539 	dma_addr_t payload_addr;
540 
541 	/* assert(tag <= field_max(IP_PACKET_TAG_STATUS_TAG_FMASK)); */
542 
543 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
544 	payload = &cmd_payload->ip_packet_tag_status;
545 
546 	payload->tag = u64_encode_bits(tag, IP_PACKET_TAG_STATUS_TAG_FMASK);
547 
548 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
549 			  direction, opcode);
550 }
551 
552 /* Issue a small command TX data transfer */
553 static void ipa_cmd_transfer_add(struct gsi_trans *trans, u16 size)
554 {
555 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
556 	enum dma_data_direction direction = DMA_TO_DEVICE;
557 	enum ipa_cmd_opcode opcode = IPA_CMD_NONE;
558 	union ipa_cmd_payload *payload;
559 	dma_addr_t payload_addr;
560 
561 	/* assert(size <= sizeof(*payload)); */
562 
563 	/* Just transfer a zero-filled payload structure */
564 	payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
565 
566 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
567 			  direction, opcode);
568 }
569 
570 void ipa_cmd_tag_process_add(struct gsi_trans *trans)
571 {
572 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
573 	struct ipa_endpoint *endpoint;
574 
575 	endpoint = ipa->name_map[IPA_ENDPOINT_AP_LAN_RX];
576 
577 	ipa_cmd_register_write_add(trans, 0, 0, 0, true);
578 	ipa_cmd_ip_packet_init_add(trans, endpoint->endpoint_id);
579 	ipa_cmd_ip_tag_status_add(trans, 0xcba987654321);
580 	ipa_cmd_transfer_add(trans, 4);
581 }
582 
583 /* Returns the number of commands required for the tag process */
584 u32 ipa_cmd_tag_process_count(void)
585 {
586 	return 4;
587 }
588 
589 void ipa_cmd_tag_process(struct ipa *ipa)
590 {
591 	u32 count = ipa_cmd_tag_process_count();
592 	struct gsi_trans *trans;
593 
594 	trans = ipa_cmd_trans_alloc(ipa, count);
595 	if (trans) {
596 		ipa_cmd_tag_process_add(trans);
597 		gsi_trans_commit_wait(trans);
598 	} else {
599 		dev_err(&ipa->pdev->dev,
600 			"error allocating %u entry tag transaction\n", count);
601 	}
602 }
603 
604 static struct ipa_cmd_info *
605 ipa_cmd_info_alloc(struct ipa_endpoint *endpoint, u32 tre_count)
606 {
607 	struct gsi_channel *channel;
608 
609 	channel = &endpoint->ipa->gsi.channel[endpoint->channel_id];
610 
611 	return gsi_trans_pool_alloc(&channel->trans_info.info_pool, tre_count);
612 }
613 
614 /* Allocate a transaction for the command TX endpoint */
615 struct gsi_trans *ipa_cmd_trans_alloc(struct ipa *ipa, u32 tre_count)
616 {
617 	struct ipa_endpoint *endpoint;
618 	struct gsi_trans *trans;
619 
620 	endpoint = ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX];
621 
622 	trans = gsi_channel_trans_alloc(&ipa->gsi, endpoint->channel_id,
623 					tre_count, DMA_NONE);
624 	if (trans)
625 		trans->info = ipa_cmd_info_alloc(endpoint, tre_count);
626 
627 	return trans;
628 }
629