xref: /linux/drivers/net/ipa/ipa_cmd.c (revision dd093fb0)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4  * Copyright (C) 2019-2022 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, and use a single GSI TRE.  Each immediate command
30  * has a well-defined format, having a payload of a known length.  This
31  * 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 AP
33  * memory and is described by a single scatterlist entry in its transaction.
34  * Commands do not require a transaction completion callback, and are
35  * always issued using gsi_trans_commit_wait().
36  */
37 
38 /* Some commands can wait until indicated pipeline stages are clear */
39 enum pipeline_clear_options {
40 	pipeline_clear_hps		= 0x0,
41 	pipeline_clear_src_grp		= 0x1,
42 	pipeline_clear_full		= 0x2,
43 };
44 
45 /* IPA_CMD_IP_V{4,6}_{FILTER,ROUTING}_INIT */
46 
47 struct ipa_cmd_hw_ip_fltrt_init {
48 	__le64 hash_rules_addr;
49 	__le64 flags;
50 	__le64 nhash_rules_addr;
51 };
52 
53 /* Field masks for ipa_cmd_hw_ip_fltrt_init structure fields */
54 #define IP_FLTRT_FLAGS_HASH_SIZE_FMASK			GENMASK_ULL(11, 0)
55 #define IP_FLTRT_FLAGS_HASH_ADDR_FMASK			GENMASK_ULL(27, 12)
56 #define IP_FLTRT_FLAGS_NHASH_SIZE_FMASK			GENMASK_ULL(39, 28)
57 #define IP_FLTRT_FLAGS_NHASH_ADDR_FMASK			GENMASK_ULL(55, 40)
58 
59 /* IPA_CMD_HDR_INIT_LOCAL */
60 
61 struct ipa_cmd_hw_hdr_init_local {
62 	__le64 hdr_table_addr;
63 	__le32 flags;
64 	__le32 reserved;
65 };
66 
67 /* Field masks for ipa_cmd_hw_hdr_init_local structure fields */
68 #define HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK		GENMASK(11, 0)
69 #define HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK		GENMASK(27, 12)
70 
71 /* IPA_CMD_REGISTER_WRITE */
72 
73 /* For IPA v4.0+, the pipeline clear options are encoded in the opcode */
74 #define REGISTER_WRITE_OPCODE_SKIP_CLEAR_FMASK		GENMASK(8, 8)
75 #define REGISTER_WRITE_OPCODE_CLEAR_OPTION_FMASK	GENMASK(10, 9)
76 
77 struct ipa_cmd_register_write {
78 	__le16 flags;		/* Unused/reserved prior to IPA v4.0 */
79 	__le16 offset;
80 	__le32 value;
81 	__le32 value_mask;
82 	__le32 clear_options;	/* Unused/reserved for IPA v4.0+ */
83 };
84 
85 /* Field masks for ipa_cmd_register_write structure fields */
86 /* The next field is present for IPA v4.0+ */
87 #define REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK		GENMASK(14, 11)
88 /* The next field is not present for IPA v4.0+ */
89 #define REGISTER_WRITE_FLAGS_SKIP_CLEAR_FMASK		GENMASK(15, 15)
90 
91 /* The next field and its values are not present for IPA v4.0+ */
92 #define REGISTER_WRITE_CLEAR_OPTIONS_FMASK		GENMASK(1, 0)
93 
94 /* IPA_CMD_IP_PACKET_INIT */
95 
96 struct ipa_cmd_ip_packet_init {
97 	u8 dest_endpoint;
98 	u8 reserved[7];
99 };
100 
101 /* Field masks for ipa_cmd_ip_packet_init dest_endpoint field */
102 #define IPA_PACKET_INIT_DEST_ENDPOINT_FMASK		GENMASK(4, 0)
103 
104 /* IPA_CMD_DMA_SHARED_MEM */
105 
106 /* For IPA v4.0+, this opcode gets modified with pipeline clear options */
107 
108 #define DMA_SHARED_MEM_OPCODE_SKIP_CLEAR_FMASK		GENMASK(8, 8)
109 #define DMA_SHARED_MEM_OPCODE_CLEAR_OPTION_FMASK	GENMASK(10, 9)
110 
111 struct ipa_cmd_hw_dma_mem_mem {
112 	__le16 clear_after_read; /* 0 or DMA_SHARED_MEM_CLEAR_AFTER_READ */
113 	__le16 size;
114 	__le16 local_addr;
115 	__le16 flags;
116 	__le64 system_addr;
117 };
118 
119 /* Flag allowing atomic clear of target region after reading data (v4.0+)*/
120 #define DMA_SHARED_MEM_CLEAR_AFTER_READ			GENMASK(15, 15)
121 
122 /* Field masks for ipa_cmd_hw_dma_mem_mem structure fields */
123 #define DMA_SHARED_MEM_FLAGS_DIRECTION_FMASK		GENMASK(0, 0)
124 /* The next two fields are not present for IPA v4.0+ */
125 #define DMA_SHARED_MEM_FLAGS_SKIP_CLEAR_FMASK		GENMASK(1, 1)
126 #define DMA_SHARED_MEM_FLAGS_CLEAR_OPTIONS_FMASK	GENMASK(3, 2)
127 
128 /* IPA_CMD_IP_PACKET_TAG_STATUS */
129 
130 struct ipa_cmd_ip_packet_tag_status {
131 	__le64 tag;
132 };
133 
134 #define IP_PACKET_TAG_STATUS_TAG_FMASK			GENMASK_ULL(63, 16)
135 
136 /* Immediate command payload */
137 union ipa_cmd_payload {
138 	struct ipa_cmd_hw_ip_fltrt_init table_init;
139 	struct ipa_cmd_hw_hdr_init_local hdr_init_local;
140 	struct ipa_cmd_register_write register_write;
141 	struct ipa_cmd_ip_packet_init ip_packet_init;
142 	struct ipa_cmd_hw_dma_mem_mem dma_shared_mem;
143 	struct ipa_cmd_ip_packet_tag_status ip_packet_tag_status;
144 };
145 
146 static void ipa_cmd_validate_build(void)
147 {
148 	/* The size of a filter table needs to fit into fields in the
149 	 * ipa_cmd_hw_ip_fltrt_init structure.  Although hashed tables
150 	 * might not be used, non-hashed and hashed tables have the same
151 	 * maximum size.  IPv4 and IPv6 filter tables have the same number
152 	 * of entries.
153 	 */
154 	/* Hashed and non-hashed fields are assumed to be the same size */
155 	BUILD_BUG_ON(field_max(IP_FLTRT_FLAGS_HASH_SIZE_FMASK) !=
156 		     field_max(IP_FLTRT_FLAGS_NHASH_SIZE_FMASK));
157 	BUILD_BUG_ON(field_max(IP_FLTRT_FLAGS_HASH_ADDR_FMASK) !=
158 		     field_max(IP_FLTRT_FLAGS_NHASH_ADDR_FMASK));
159 
160 	/* Valid endpoint numbers must fit in the IP packet init command */
161 	BUILD_BUG_ON(field_max(IPA_PACKET_INIT_DEST_ENDPOINT_FMASK) <
162 		     IPA_ENDPOINT_MAX - 1);
163 }
164 
165 /* Validate a memory region holding a table */
166 bool ipa_cmd_table_init_valid(struct ipa *ipa, const struct ipa_mem *mem,
167 			      bool route)
168 {
169 	u32 offset_max = field_max(IP_FLTRT_FLAGS_NHASH_ADDR_FMASK);
170 	u32 size_max = field_max(IP_FLTRT_FLAGS_NHASH_SIZE_FMASK);
171 	const char *table = route ? "route" : "filter";
172 	struct device *dev = &ipa->pdev->dev;
173 	u32 size;
174 
175 	size = route ? ipa->route_count : ipa->filter_count + 1;
176 	size *= sizeof(__le64);
177 
178 	/* Size must fit in the immediate command field that holds it */
179 	if (size > size_max) {
180 		dev_err(dev, "%s table region size too large\n", table);
181 		dev_err(dev, "    (0x%04x > 0x%04x)\n", size, size_max);
182 
183 		return false;
184 	}
185 
186 	/* Offset must fit in the immediate command field that holds it */
187 	if (mem->offset > offset_max ||
188 	    ipa->mem_offset > offset_max - mem->offset) {
189 		dev_err(dev, "%s table region offset too large\n", table);
190 		dev_err(dev, "    (0x%04x + 0x%04x > 0x%04x)\n",
191 			ipa->mem_offset, mem->offset, offset_max);
192 
193 		return false;
194 	}
195 
196 	return true;
197 }
198 
199 /* Validate the memory region that holds headers */
200 static bool ipa_cmd_header_init_local_valid(struct ipa *ipa)
201 {
202 	struct device *dev = &ipa->pdev->dev;
203 	const struct ipa_mem *mem;
204 	u32 offset_max;
205 	u32 size_max;
206 	u32 offset;
207 	u32 size;
208 
209 	/* In ipa_cmd_hdr_init_local_add() we record the offset and size of
210 	 * the header table memory area in an immediate command.  Make sure
211 	 * the offset and size fit in the fields that need to hold them, and
212 	 * that the entire range is within the overall IPA memory range.
213 	 */
214 	offset_max = field_max(HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK);
215 	size_max = field_max(HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK);
216 
217 	/* The header memory area contains both the modem and AP header
218 	 * regions.  The modem portion defines the address of the region.
219 	 */
220 	mem = ipa_mem_find(ipa, IPA_MEM_MODEM_HEADER);
221 	offset = mem->offset;
222 	size = mem->size;
223 
224 	/* Make sure the offset fits in the IPA command */
225 	if (offset > offset_max || ipa->mem_offset > offset_max - offset) {
226 		dev_err(dev, "header table region offset too large\n");
227 		dev_err(dev, "    (0x%04x + 0x%04x > 0x%04x)\n",
228 			ipa->mem_offset, offset, offset_max);
229 
230 		return false;
231 	}
232 
233 	/* Add the size of the AP portion (if defined) to the combined size */
234 	mem = ipa_mem_find(ipa, IPA_MEM_AP_HEADER);
235 	if (mem)
236 		size += mem->size;
237 
238 	/* Make sure the combined size fits in the IPA command */
239 	if (size > size_max) {
240 		dev_err(dev, "header table region size too large\n");
241 		dev_err(dev, "    (0x%04x > 0x%08x)\n", size, size_max);
242 
243 		return false;
244 	}
245 
246 	return true;
247 }
248 
249 /* Indicate whether an offset can be used with a register_write command */
250 static bool ipa_cmd_register_write_offset_valid(struct ipa *ipa,
251 						const char *name, u32 offset)
252 {
253 	struct ipa_cmd_register_write *payload;
254 	struct device *dev = &ipa->pdev->dev;
255 	u32 offset_max;
256 	u32 bit_count;
257 
258 	/* The maximum offset in a register_write immediate command depends
259 	 * on the version of IPA.  A 16 bit offset is always supported,
260 	 * but starting with IPA v4.0 some additional high-order bits are
261 	 * allowed.
262 	 */
263 	bit_count = BITS_PER_BYTE * sizeof(payload->offset);
264 	if (ipa->version >= IPA_VERSION_4_0)
265 		bit_count += hweight32(REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK);
266 	BUILD_BUG_ON(bit_count > 32);
267 	offset_max = ~0U >> (32 - bit_count);
268 
269 	/* Make sure the offset can be represented by the field(s)
270 	 * that holds it.  Also make sure the offset is not outside
271 	 * the overall IPA memory range.
272 	 */
273 	if (offset > offset_max || ipa->mem_offset > offset_max - offset) {
274 		dev_err(dev, "%s offset too large 0x%04x + 0x%04x > 0x%04x)\n",
275 			name, ipa->mem_offset, offset, offset_max);
276 		return false;
277 	}
278 
279 	return true;
280 }
281 
282 /* Check whether offsets passed to register_write are valid */
283 static bool ipa_cmd_register_write_valid(struct ipa *ipa)
284 {
285 	const struct ipa_reg *reg;
286 	const char *name;
287 	u32 offset;
288 
289 	/* If hashed tables are supported, ensure the hash flush register
290 	 * offset will fit in a register write IPA immediate command.
291 	 */
292 	if (ipa_table_hash_support(ipa)) {
293 		reg = ipa_reg(ipa, FILT_ROUT_HASH_FLUSH);
294 		offset = ipa_reg_offset(reg);
295 		name = "filter/route hash flush";
296 		if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
297 			return false;
298 	}
299 
300 	/* Each endpoint can have a status endpoint associated with it,
301 	 * and this is recorded in an endpoint register.  If the modem
302 	 * crashes, we reset the status endpoint for all modem endpoints
303 	 * using a register write IPA immediate command.  Make sure the
304 	 * worst case (highest endpoint number) offset of that endpoint
305 	 * fits in the register write command field(s) that must hold it.
306 	 */
307 	reg = ipa_reg(ipa, ENDP_STATUS);
308 	offset = ipa_reg_n_offset(reg, IPA_ENDPOINT_COUNT - 1);
309 	name = "maximal endpoint status";
310 	if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
311 		return false;
312 
313 	return true;
314 }
315 
316 int ipa_cmd_pool_init(struct gsi_channel *channel, u32 tre_max)
317 {
318 	struct gsi_trans_info *trans_info = &channel->trans_info;
319 	struct device *dev = channel->gsi->dev;
320 
321 	/* Command payloads are allocated one at a time, but a single
322 	 * transaction can require up to the maximum supported by the
323 	 * channel; treat them as if they were allocated all at once.
324 	 */
325 	return gsi_trans_pool_init_dma(dev, &trans_info->cmd_pool,
326 				       sizeof(union ipa_cmd_payload),
327 				       tre_max, channel->trans_tre_max);
328 }
329 
330 void ipa_cmd_pool_exit(struct gsi_channel *channel)
331 {
332 	struct gsi_trans_info *trans_info = &channel->trans_info;
333 	struct device *dev = channel->gsi->dev;
334 
335 	gsi_trans_pool_exit_dma(dev, &trans_info->cmd_pool);
336 }
337 
338 static union ipa_cmd_payload *
339 ipa_cmd_payload_alloc(struct ipa *ipa, dma_addr_t *addr)
340 {
341 	struct gsi_trans_info *trans_info;
342 	struct ipa_endpoint *endpoint;
343 
344 	endpoint = ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX];
345 	trans_info = &ipa->gsi.channel[endpoint->channel_id].trans_info;
346 
347 	return gsi_trans_pool_alloc_dma(&trans_info->cmd_pool, addr);
348 }
349 
350 /* If hash_size is 0, hash_offset and hash_addr ignored. */
351 void ipa_cmd_table_init_add(struct gsi_trans *trans,
352 			    enum ipa_cmd_opcode opcode, u16 size, u32 offset,
353 			    dma_addr_t addr, u16 hash_size, u32 hash_offset,
354 			    dma_addr_t hash_addr)
355 {
356 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
357 	struct ipa_cmd_hw_ip_fltrt_init *payload;
358 	union ipa_cmd_payload *cmd_payload;
359 	dma_addr_t payload_addr;
360 	u64 val;
361 
362 	/* Record the non-hash table offset and size */
363 	offset += ipa->mem_offset;
364 	val = u64_encode_bits(offset, IP_FLTRT_FLAGS_NHASH_ADDR_FMASK);
365 	val |= u64_encode_bits(size, IP_FLTRT_FLAGS_NHASH_SIZE_FMASK);
366 
367 	/* The hash table offset and address are zero if its size is 0 */
368 	if (hash_size) {
369 		/* Record the hash table offset and size */
370 		hash_offset += ipa->mem_offset;
371 		val |= u64_encode_bits(hash_offset,
372 				       IP_FLTRT_FLAGS_HASH_ADDR_FMASK);
373 		val |= u64_encode_bits(hash_size,
374 				       IP_FLTRT_FLAGS_HASH_SIZE_FMASK);
375 	}
376 
377 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
378 	payload = &cmd_payload->table_init;
379 
380 	/* Fill in all offsets and sizes and the non-hash table address */
381 	if (hash_size)
382 		payload->hash_rules_addr = cpu_to_le64(hash_addr);
383 	payload->flags = cpu_to_le64(val);
384 	payload->nhash_rules_addr = cpu_to_le64(addr);
385 
386 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
387 			  opcode);
388 }
389 
390 /* Initialize header space in IPA-local memory */
391 void ipa_cmd_hdr_init_local_add(struct gsi_trans *trans, u32 offset, u16 size,
392 				dma_addr_t addr)
393 {
394 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
395 	enum ipa_cmd_opcode opcode = IPA_CMD_HDR_INIT_LOCAL;
396 	struct ipa_cmd_hw_hdr_init_local *payload;
397 	union ipa_cmd_payload *cmd_payload;
398 	dma_addr_t payload_addr;
399 	u32 flags;
400 
401 	offset += ipa->mem_offset;
402 
403 	/* With this command we tell the IPA where in its local memory the
404 	 * header tables reside.  The content of the buffer provided is
405 	 * also written via DMA into that space.  The IPA hardware owns
406 	 * the table, but the AP must initialize it.
407 	 */
408 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
409 	payload = &cmd_payload->hdr_init_local;
410 
411 	payload->hdr_table_addr = cpu_to_le64(addr);
412 	flags = u32_encode_bits(size, HDR_INIT_LOCAL_FLAGS_TABLE_SIZE_FMASK);
413 	flags |= u32_encode_bits(offset, HDR_INIT_LOCAL_FLAGS_HDR_ADDR_FMASK);
414 	payload->flags = cpu_to_le32(flags);
415 
416 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
417 			  opcode);
418 }
419 
420 void ipa_cmd_register_write_add(struct gsi_trans *trans, u32 offset, u32 value,
421 				u32 mask, bool clear_full)
422 {
423 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
424 	struct ipa_cmd_register_write *payload;
425 	union ipa_cmd_payload *cmd_payload;
426 	u32 opcode = IPA_CMD_REGISTER_WRITE;
427 	dma_addr_t payload_addr;
428 	u32 clear_option;
429 	u32 options;
430 	u16 flags;
431 
432 	/* pipeline_clear_src_grp is not used */
433 	clear_option = clear_full ? pipeline_clear_full : pipeline_clear_hps;
434 
435 	/* IPA v4.0+ represents the pipeline clear options in the opcode.  It
436 	 * also supports a larger offset by encoding additional high-order
437 	 * bits in the payload flags field.
438 	 */
439 	if (ipa->version >= IPA_VERSION_4_0) {
440 		u16 offset_high;
441 		u32 val;
442 
443 		/* Opcode encodes pipeline clear options */
444 		/* SKIP_CLEAR is always 0 (don't skip pipeline clear) */
445 		val = u16_encode_bits(clear_option,
446 				      REGISTER_WRITE_OPCODE_CLEAR_OPTION_FMASK);
447 		opcode |= val;
448 
449 		/* Extract the high 4 bits from the offset */
450 		offset_high = (u16)u32_get_bits(offset, GENMASK(19, 16));
451 		offset &= (1 << 16) - 1;
452 
453 		/* Extract the top 4 bits and encode it into the flags field */
454 		flags = u16_encode_bits(offset_high,
455 				REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK);
456 		options = 0;	/* reserved */
457 
458 	} else {
459 		flags = 0;	/* SKIP_CLEAR flag is always 0 */
460 		options = u16_encode_bits(clear_option,
461 					  REGISTER_WRITE_CLEAR_OPTIONS_FMASK);
462 	}
463 
464 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
465 	payload = &cmd_payload->register_write;
466 
467 	payload->flags = cpu_to_le16(flags);
468 	payload->offset = cpu_to_le16((u16)offset);
469 	payload->value = cpu_to_le32(value);
470 	payload->value_mask = cpu_to_le32(mask);
471 	payload->clear_options = cpu_to_le32(options);
472 
473 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
474 			  opcode);
475 }
476 
477 /* Skip IP packet processing on the next data transfer on a TX channel */
478 static void ipa_cmd_ip_packet_init_add(struct gsi_trans *trans, u8 endpoint_id)
479 {
480 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
481 	enum ipa_cmd_opcode opcode = IPA_CMD_IP_PACKET_INIT;
482 	struct ipa_cmd_ip_packet_init *payload;
483 	union ipa_cmd_payload *cmd_payload;
484 	dma_addr_t payload_addr;
485 
486 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
487 	payload = &cmd_payload->ip_packet_init;
488 
489 	payload->dest_endpoint = u8_encode_bits(endpoint_id,
490 					IPA_PACKET_INIT_DEST_ENDPOINT_FMASK);
491 
492 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
493 			  opcode);
494 }
495 
496 /* Use a DMA command to read or write a block of IPA-resident memory */
497 void ipa_cmd_dma_shared_mem_add(struct gsi_trans *trans, u32 offset, u16 size,
498 				dma_addr_t addr, bool toward_ipa)
499 {
500 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
501 	enum ipa_cmd_opcode opcode = IPA_CMD_DMA_SHARED_MEM;
502 	struct ipa_cmd_hw_dma_mem_mem *payload;
503 	union ipa_cmd_payload *cmd_payload;
504 	dma_addr_t payload_addr;
505 	u16 flags;
506 
507 	/* size and offset must fit in 16 bit fields */
508 	WARN_ON(!size);
509 	WARN_ON(size > U16_MAX);
510 	WARN_ON(offset > U16_MAX || ipa->mem_offset > U16_MAX - offset);
511 
512 	offset += ipa->mem_offset;
513 
514 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
515 	payload = &cmd_payload->dma_shared_mem;
516 
517 	/* payload->clear_after_read was reserved prior to IPA v4.0.  It's
518 	 * never needed for current code, so it's 0 regardless of version.
519 	 */
520 	payload->size = cpu_to_le16(size);
521 	payload->local_addr = cpu_to_le16(offset);
522 	/* payload->flags:
523 	 *   direction:		0 = write to IPA, 1 read from IPA
524 	 * Starting at v4.0 these are reserved; either way, all zero:
525 	 *   pipeline clear:	0 = wait for pipeline clear (don't skip)
526 	 *   clear_options:	0 = pipeline_clear_hps
527 	 * Instead, for v4.0+ these are encoded in the opcode.  But again
528 	 * since both values are 0 we won't bother OR'ing them in.
529 	 */
530 	flags = toward_ipa ? 0 : DMA_SHARED_MEM_FLAGS_DIRECTION_FMASK;
531 	payload->flags = cpu_to_le16(flags);
532 	payload->system_addr = cpu_to_le64(addr);
533 
534 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
535 			  opcode);
536 }
537 
538 static void ipa_cmd_ip_tag_status_add(struct gsi_trans *trans)
539 {
540 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
541 	enum ipa_cmd_opcode opcode = IPA_CMD_IP_PACKET_TAG_STATUS;
542 	struct ipa_cmd_ip_packet_tag_status *payload;
543 	union ipa_cmd_payload *cmd_payload;
544 	dma_addr_t payload_addr;
545 
546 	cmd_payload = ipa_cmd_payload_alloc(ipa, &payload_addr);
547 	payload = &cmd_payload->ip_packet_tag_status;
548 
549 	payload->tag = le64_encode_bits(0, IP_PACKET_TAG_STATUS_TAG_FMASK);
550 
551 	gsi_trans_cmd_add(trans, payload, sizeof(*payload), payload_addr,
552 			  opcode);
553 }
554 
555 /* Issue a small command TX data transfer */
556 static void ipa_cmd_transfer_add(struct gsi_trans *trans)
557 {
558 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
559 	enum ipa_cmd_opcode opcode = IPA_CMD_NONE;
560 	union ipa_cmd_payload *payload;
561 	dma_addr_t payload_addr;
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 			  opcode);
568 }
569 
570 /* Add immediate commands to a transaction to clear the hardware pipeline */
571 void ipa_cmd_pipeline_clear_add(struct gsi_trans *trans)
572 {
573 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
574 	struct ipa_endpoint *endpoint;
575 
576 	/* This will complete when the transfer is received */
577 	reinit_completion(&ipa->completion);
578 
579 	/* Issue a no-op register write command (mask 0 means no write) */
580 	ipa_cmd_register_write_add(trans, 0, 0, 0, true);
581 
582 	/* Send a data packet through the IPA pipeline.  The packet_init
583 	 * command says to send the next packet directly to the exception
584 	 * endpoint without any other IPA processing.  The tag_status
585 	 * command requests that status be generated on completion of
586 	 * that transfer, and that it will be tagged with a value.
587 	 * Finally, the transfer command sends a small packet of data
588 	 * (instead of a command) using the command endpoint.
589 	 */
590 	endpoint = ipa->name_map[IPA_ENDPOINT_AP_LAN_RX];
591 	ipa_cmd_ip_packet_init_add(trans, endpoint->endpoint_id);
592 	ipa_cmd_ip_tag_status_add(trans);
593 	ipa_cmd_transfer_add(trans);
594 }
595 
596 /* Returns the number of commands required to clear the pipeline */
597 u32 ipa_cmd_pipeline_clear_count(void)
598 {
599 	return 4;
600 }
601 
602 void ipa_cmd_pipeline_clear_wait(struct ipa *ipa)
603 {
604 	wait_for_completion(&ipa->completion);
605 }
606 
607 /* Allocate a transaction for the command TX endpoint */
608 struct gsi_trans *ipa_cmd_trans_alloc(struct ipa *ipa, u32 tre_count)
609 {
610 	struct ipa_endpoint *endpoint;
611 
612 	if (WARN_ON(tre_count > IPA_COMMAND_TRANS_TRE_MAX))
613 		return NULL;
614 
615 	endpoint = ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX];
616 
617 	return gsi_channel_trans_alloc(&ipa->gsi, endpoint->channel_id,
618 				       tre_count, DMA_NONE);
619 }
620 
621 /* Init function for immediate commands; there is no ipa_cmd_exit() */
622 int ipa_cmd_init(struct ipa *ipa)
623 {
624 	ipa_cmd_validate_build();
625 
626 	if (!ipa_cmd_header_init_local_valid(ipa))
627 		return -EINVAL;
628 
629 	if (!ipa_cmd_register_write_valid(ipa))
630 		return -EINVAL;
631 
632 	return 0;
633 }
634