xref: /linux/drivers/net/ipa/ipa_table.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4  * Copyright (C) 2018-2024 Linaro Ltd.
5  */
6 
7 #include <linux/bitops.h>
8 #include <linux/build_bug.h>
9 #include <linux/device.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/io.h>
12 #include <linux/types.h>
13 
14 #include "gsi.h"
15 #include "gsi_trans.h"
16 #include "ipa.h"
17 #include "ipa_cmd.h"
18 #include "ipa_endpoint.h"
19 #include "ipa_mem.h"
20 #include "ipa_reg.h"
21 #include "ipa_table.h"
22 #include "ipa_version.h"
23 
24 /**
25  * DOC: IPA Filter and Route Tables
26  *
27  * The IPA has tables defined in its local (IPA-resident) memory that define
28  * filter and routing rules.  An entry in either of these tables is a little
29  * endian 64-bit "slot" that holds the address of a rule definition.  (The
30  * size of these slots is 64 bits regardless of the host DMA address size.)
31  *
32  * Separate tables (both filter and route) are used for IPv4 and IPv6.  There
33  * is normally another set of "hashed" filter and route tables, which are
34  * used with a hash of message metadata.  Hashed operation is not supported
35  * by all IPA hardware (IPA v4.2 doesn't support hashed tables).
36  *
37  * Rules can be in local memory or in DRAM (system memory).  The offset of
38  * an object (such as a route or filter table) in IPA-resident memory must
39  * 128-byte aligned.  An object in system memory (such as a route or filter
40  * rule) must be at an 8-byte aligned address.  We currently only place
41  * route or filter rules in system memory.
42  *
43  * A rule consists of a contiguous block of 32-bit values terminated with
44  * 32 zero bits.  A special "zero entry" rule consisting of 64 zero bits
45  * represents "no filtering" or "no routing," and is the reset value for
46  * filter or route table rules.
47  *
48  * Each filter rule is associated with an AP or modem TX endpoint, though
49  * not all TX endpoints support filtering.  The first 64-bit slot in a
50  * filter table is a bitmap indicating which endpoints have entries in
51  * the table.  Each set bit in this bitmap indicates the presence of the
52  * address of a filter rule in the memory following the bitmap.  Until IPA
53  * v5.0,  the low-order bit (bit 0) in this bitmap represents a special
54  * global filter, which applies to all traffic.  Otherwise the position of
55  * each set bit represents an endpoint for which a filter rule is defined.
56  *
57  * The global rule is not used in current code, and support for it is
58  * removed starting at IPA v5.0.  For IPA v5.0+, the endpoint bitmap
59  * position defines the endpoint ID--i.e. if bit 1 is set in the endpoint
60  * bitmap, endpoint 1 has a filter rule.  Older versions of IPA represent
61  * the presence of a filter rule for endpoint X by bit (X + 1) being set.
62  * I.e., bit 1 set indicates the presence of a filter rule for endpoint 0,
63  * and bit 3 set means there is a filter rule present for endpoint 2.
64  *
65  * Each filter table entry has the address of a set of equations that
66  * implement a filter rule.  So following the endpoint bitmap there
67  * will be such an address/entry for each endpoint with a set bit in
68  * the bitmap.
69  *
70  * The AP initializes all entries in a filter table to refer to a "zero"
71  * rule.  Once initialized, the modem and AP update the entries for
72  * endpoints they "own" directly.  Currently the AP does not use the IPA
73  * filtering functionality.
74  *
75  * This diagram shows an example of a filter table with an endpoint
76  * bitmap as defined prior to IPA v5.0.
77  *
78  *                    IPA Filter Table
79  *                 ----------------------
80  * endpoint bitmap | 0x0000000000000048 | Bits 3 and 6 set (endpoints 2 and 5)
81  *                 |--------------------|
82  * 1st endpoint    | 0x000123456789abc0 | DMA address for modem endpoint 2 rule
83  *                 |--------------------|
84  * 2nd endpoint    | 0x000123456789abf0 | DMA address for AP endpoint 5 rule
85  *                 |--------------------|
86  * (unused)        |                    | (Unused space in filter table)
87  *                 |--------------------|
88  *                          . . .
89  *                 |--------------------|
90  * (unused)        |                    | (Unused space in filter table)
91  *                 ----------------------
92  *
93  * The set of available route rules is divided about equally between the AP
94  * and modem.  The AP initializes all entries in a route table to refer to
95  * a "zero entry".  Once initialized, the modem and AP are responsible for
96  * updating their own entries.  All entries in a route table are usable,
97  * though the AP currently does not use the IPA routing functionality.
98  *
99  *                    IPA Route Table
100  *                 ----------------------
101  * 1st modem route | 0x0001234500001100 | DMA address for first route rule
102  *                 |--------------------|
103  * 2nd modem route | 0x0001234500001140 | DMA address for second route rule
104  *                 |--------------------|
105  *                          . . .
106  *                 |--------------------|
107  * Last modem route| 0x0001234500002280 | DMA address for Nth route rule
108  *                 |--------------------|
109  * 1st AP route    | 0x0001234500001100 | DMA address for route rule (N+1)
110  *                 |--------------------|
111  * 2nd AP route    | 0x0001234500001140 | DMA address for next route rule
112  *                 |--------------------|
113  *                          . . .
114  *                 |--------------------|
115  * Last AP route   | 0x0001234500002280 | DMA address for last route rule
116  *                 ----------------------
117  */
118 
119 /* Filter or route rules consist of a set of 32-bit values followed by a
120  * 32-bit all-zero rule list terminator.  The "zero rule" is simply an
121  * all-zero rule followed by the list terminator.
122  */
123 #define IPA_ZERO_RULE_SIZE		(2 * sizeof(__le32))
124 
125 /* Check things that can be validated at build time. */
126 static void ipa_table_validate_build(void)
127 {
128 	/* Filter and route tables contain DMA addresses that refer
129 	 * to filter or route rules.  But the size of a table entry
130 	 * is 64 bits regardless of what the size of an AP DMA address
131 	 * is.  A fixed constant defines the size of an entry, and
132 	 * code in ipa_table_init() uses a pointer to __le64 to
133 	 * initialize tables.
134 	 */
135 	BUILD_BUG_ON(sizeof(dma_addr_t) > sizeof(__le64));
136 
137 	/* A "zero rule" is used to represent no filtering or no routing.
138 	 * It is a 64-bit block of zeroed memory.  Code in ipa_table_init()
139 	 * assumes that it can be written using a pointer to __le64.
140 	 */
141 	BUILD_BUG_ON(IPA_ZERO_RULE_SIZE != sizeof(__le64));
142 }
143 
144 static const struct ipa_mem *
145 ipa_table_mem(struct ipa *ipa, bool filter, bool hashed, bool ipv6)
146 {
147 	enum ipa_mem_id mem_id;
148 
149 	mem_id = filter ? hashed ? ipv6 ? IPA_MEM_V6_FILTER_HASHED
150 					: IPA_MEM_V4_FILTER_HASHED
151 				 : ipv6 ? IPA_MEM_V6_FILTER
152 					: IPA_MEM_V4_FILTER
153 			: hashed ? ipv6 ? IPA_MEM_V6_ROUTE_HASHED
154 					: IPA_MEM_V4_ROUTE_HASHED
155 				 : ipv6 ? IPA_MEM_V6_ROUTE
156 					: IPA_MEM_V4_ROUTE;
157 
158 	return ipa_mem_find(ipa, mem_id);
159 }
160 
161 /* Return true if hashed tables are supported */
162 bool ipa_table_hash_support(struct ipa *ipa)
163 {
164 	return ipa->version != IPA_VERSION_4_2;
165 }
166 
167 bool ipa_filtered_valid(struct ipa *ipa, u64 filtered)
168 {
169 	struct device *dev = ipa->dev;
170 	u32 count;
171 
172 	if (!filtered) {
173 		dev_err(dev, "at least one filtering endpoint is required\n");
174 
175 		return false;
176 	}
177 
178 	count = hweight64(filtered);
179 	if (count > ipa->filter_count) {
180 		dev_err(dev, "too many filtering endpoints (%u > %u)\n",
181 			count, ipa->filter_count);
182 
183 		return false;
184 	}
185 
186 	return true;
187 }
188 
189 /* Zero entry count means no table, so just return a 0 address */
190 static dma_addr_t ipa_table_addr(struct ipa *ipa, bool filter_mask, u16 count)
191 {
192 	u32 skip;
193 
194 	if (!count)
195 		return 0;
196 
197 	WARN_ON(count > max_t(u32, ipa->filter_count, ipa->route_count));
198 
199 	/* Skip over the zero rule and possibly the filter mask */
200 	skip = filter_mask ? 1 : 2;
201 
202 	return ipa->table_addr + skip * sizeof(*ipa->table_virt);
203 }
204 
205 static void ipa_table_reset_add(struct gsi_trans *trans, bool filter,
206 				bool hashed, bool ipv6, u16 first, u16 count)
207 {
208 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
209 	const struct ipa_mem *mem;
210 	dma_addr_t addr;
211 	u32 offset;
212 	u16 size;
213 
214 	/* Nothing to do if the memory region is doesn't exist or is empty */
215 	mem = ipa_table_mem(ipa, filter, hashed, ipv6);
216 	if (!mem || !mem->size)
217 		return;
218 
219 	if (filter)
220 		first++;	/* skip over bitmap */
221 
222 	offset = mem->offset + first * sizeof(__le64);
223 	size = count * sizeof(__le64);
224 	addr = ipa_table_addr(ipa, false, count);
225 
226 	ipa_cmd_dma_shared_mem_add(trans, offset, size, addr, true);
227 }
228 
229 /* Reset entries in a single filter table belonging to either the AP or
230  * modem to refer to the zero entry.  The memory region supplied will be
231  * for the IPv4 and IPv6 non-hashed and hashed filter tables.
232  */
233 static int
234 ipa_filter_reset_table(struct ipa *ipa, bool hashed, bool ipv6, bool modem)
235 {
236 	u64 ep_mask = ipa->filtered;
237 	struct gsi_trans *trans;
238 	enum gsi_ee_id ee_id;
239 
240 	trans = ipa_cmd_trans_alloc(ipa, hweight64(ep_mask));
241 	if (!trans) {
242 		dev_err(ipa->dev, "no transaction for %s filter reset\n",
243 			modem ? "modem" : "AP");
244 		return -EBUSY;
245 	}
246 
247 	ee_id = modem ? GSI_EE_MODEM : GSI_EE_AP;
248 	while (ep_mask) {
249 		u32 endpoint_id = __ffs(ep_mask);
250 		struct ipa_endpoint *endpoint;
251 
252 		ep_mask ^= BIT(endpoint_id);
253 
254 		endpoint = &ipa->endpoint[endpoint_id];
255 		if (endpoint->ee_id != ee_id)
256 			continue;
257 
258 		ipa_table_reset_add(trans, true, hashed, ipv6, endpoint_id, 1);
259 	}
260 
261 	gsi_trans_commit_wait(trans);
262 
263 	return 0;
264 }
265 
266 /* Theoretically, each filter table could have more filter slots to
267  * update than the maximum number of commands in a transaction.  So
268  * we do each table separately.
269  */
270 static int ipa_filter_reset(struct ipa *ipa, bool modem)
271 {
272 	int ret;
273 
274 	ret = ipa_filter_reset_table(ipa, false, false, modem);
275 	if (ret)
276 		return ret;
277 
278 	ret = ipa_filter_reset_table(ipa, false, true, modem);
279 	if (ret || !ipa_table_hash_support(ipa))
280 		return ret;
281 
282 	ret = ipa_filter_reset_table(ipa, true, false, modem);
283 	if (ret)
284 		return ret;
285 
286 	return ipa_filter_reset_table(ipa, true, true, modem);
287 }
288 
289 /* The AP routes and modem routes are each contiguous within the
290  * table.  We can update each table with a single command, and we
291  * won't exceed the per-transaction command limit.
292  * */
293 static int ipa_route_reset(struct ipa *ipa, bool modem)
294 {
295 	bool hash_support = ipa_table_hash_support(ipa);
296 	u32 modem_route_count = ipa->modem_route_count;
297 	struct gsi_trans *trans;
298 	u16 first;
299 	u16 count;
300 
301 	trans = ipa_cmd_trans_alloc(ipa, hash_support ? 4 : 2);
302 	if (!trans) {
303 		dev_err(ipa->dev, "no transaction for %s route reset\n",
304 			modem ? "modem" : "AP");
305 		return -EBUSY;
306 	}
307 
308 	if (modem) {
309 		first = 0;
310 		count = modem_route_count;
311 	} else {
312 		first = modem_route_count;
313 		count = ipa->route_count - modem_route_count;
314 	}
315 
316 	ipa_table_reset_add(trans, false, false, false, first, count);
317 	ipa_table_reset_add(trans, false, false, true, first, count);
318 
319 	if (hash_support) {
320 		ipa_table_reset_add(trans, false, true, false, first, count);
321 		ipa_table_reset_add(trans, false, true, true, first, count);
322 	}
323 
324 	gsi_trans_commit_wait(trans);
325 
326 	return 0;
327 }
328 
329 void ipa_table_reset(struct ipa *ipa, bool modem)
330 {
331 	struct device *dev = ipa->dev;
332 	const char *ee_name;
333 	int ret;
334 
335 	ee_name = modem ? "modem" : "AP";
336 
337 	/* Report errors, but reset filter and route tables */
338 	ret = ipa_filter_reset(ipa, modem);
339 	if (ret)
340 		dev_err(dev, "error %d resetting filter table for %s\n",
341 				ret, ee_name);
342 
343 	ret = ipa_route_reset(ipa, modem);
344 	if (ret)
345 		dev_err(dev, "error %d resetting route table for %s\n",
346 				ret, ee_name);
347 }
348 
349 int ipa_table_hash_flush(struct ipa *ipa)
350 {
351 	struct gsi_trans *trans;
352 	const struct reg *reg;
353 	u32 val;
354 
355 	if (!ipa_table_hash_support(ipa))
356 		return 0;
357 
358 	trans = ipa_cmd_trans_alloc(ipa, 1);
359 	if (!trans) {
360 		dev_err(ipa->dev, "no transaction for hash flush\n");
361 		return -EBUSY;
362 	}
363 
364 	if (ipa->version < IPA_VERSION_5_0) {
365 		reg = ipa_reg(ipa, FILT_ROUT_HASH_FLUSH);
366 
367 		val = reg_bit(reg, IPV6_ROUTER_HASH);
368 		val |= reg_bit(reg, IPV6_FILTER_HASH);
369 		val |= reg_bit(reg, IPV4_ROUTER_HASH);
370 		val |= reg_bit(reg, IPV4_FILTER_HASH);
371 	} else {
372 		reg = ipa_reg(ipa, FILT_ROUT_CACHE_FLUSH);
373 
374 		/* IPA v5.0+ uses a unified cache (both IPv4 and IPv6) */
375 		val = reg_bit(reg, ROUTER_CACHE);
376 		val |= reg_bit(reg, FILTER_CACHE);
377 	}
378 
379 	ipa_cmd_register_write_add(trans, reg_offset(reg), val, val, false);
380 
381 	gsi_trans_commit_wait(trans);
382 
383 	return 0;
384 }
385 
386 static void ipa_table_init_add(struct gsi_trans *trans, bool filter, bool ipv6)
387 {
388 	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
389 	const struct ipa_mem *hash_mem;
390 	enum ipa_cmd_opcode opcode;
391 	const struct ipa_mem *mem;
392 	dma_addr_t hash_addr;
393 	dma_addr_t addr;
394 	u32 hash_offset;
395 	u32 zero_offset;
396 	u16 hash_count;
397 	u32 zero_size;
398 	u16 hash_size;
399 	u16 count;
400 	u16 size;
401 
402 	opcode = filter ? ipv6 ? IPA_CMD_IP_V6_FILTER_INIT
403 			       : IPA_CMD_IP_V4_FILTER_INIT
404 			: ipv6 ? IPA_CMD_IP_V6_ROUTING_INIT
405 			       : IPA_CMD_IP_V4_ROUTING_INIT;
406 
407 	/* The non-hashed region will exist (see ipa_table_mem_valid()) */
408 	mem = ipa_table_mem(ipa, filter, false, ipv6);
409 	hash_mem = ipa_table_mem(ipa, filter, true, ipv6);
410 	hash_offset = hash_mem ? hash_mem->offset : 0;
411 
412 	/* Compute the number of table entries to initialize */
413 	if (filter) {
414 		/* The number of filtering endpoints determines number of
415 		 * entries in the filter table; we also add one more "slot"
416 		 * to hold the bitmap itself.  The size of the hashed filter
417 		 * table is either the same as the non-hashed one, or zero.
418 		 */
419 		count = 1 + hweight64(ipa->filtered);
420 		hash_count = hash_mem && hash_mem->size ? count : 0;
421 	} else {
422 		/* The size of a route table region determines the number
423 		 * of entries it has.
424 		 */
425 		count = mem->size / sizeof(__le64);
426 		hash_count = hash_mem ? hash_mem->size / sizeof(__le64) : 0;
427 	}
428 	size = count * sizeof(__le64);
429 	hash_size = hash_count * sizeof(__le64);
430 
431 	addr = ipa_table_addr(ipa, filter, count);
432 	hash_addr = ipa_table_addr(ipa, filter, hash_count);
433 
434 	ipa_cmd_table_init_add(trans, opcode, size, mem->offset, addr,
435 			       hash_size, hash_offset, hash_addr);
436 	if (!filter)
437 		return;
438 
439 	/* Zero the unused space in the filter table */
440 	zero_offset = mem->offset + size;
441 	zero_size = mem->size - size;
442 	ipa_cmd_dma_shared_mem_add(trans, zero_offset, zero_size,
443 				   ipa->zero_addr, true);
444 	if (!hash_size)
445 		return;
446 
447 	/* Zero the unused space in the hashed filter table */
448 	zero_offset = hash_offset + hash_size;
449 	zero_size = hash_mem->size - hash_size;
450 	ipa_cmd_dma_shared_mem_add(trans, zero_offset, zero_size,
451 				   ipa->zero_addr, true);
452 }
453 
454 int ipa_table_setup(struct ipa *ipa)
455 {
456 	struct gsi_trans *trans;
457 
458 	/* We will need at most 8 TREs:
459 	 * - IPv4:
460 	 *     - One for route table initialization (non-hashed and hashed)
461 	 *     - One for filter table initialization (non-hashed and hashed)
462 	 *     - One to zero unused entries in the non-hashed filter table
463 	 *     - One to zero unused entries in the hashed filter table
464 	 * - IPv6:
465 	 *     - One for route table initialization (non-hashed and hashed)
466 	 *     - One for filter table initialization (non-hashed and hashed)
467 	 *     - One to zero unused entries in the non-hashed filter table
468 	 *     - One to zero unused entries in the hashed filter table
469 	 * All platforms support at least 8 TREs in a transaction.
470 	 */
471 	trans = ipa_cmd_trans_alloc(ipa, 8);
472 	if (!trans) {
473 		dev_err(ipa->dev, "no transaction for table setup\n");
474 		return -EBUSY;
475 	}
476 
477 	ipa_table_init_add(trans, false, false);
478 	ipa_table_init_add(trans, false, true);
479 	ipa_table_init_add(trans, true, false);
480 	ipa_table_init_add(trans, true, true);
481 
482 	gsi_trans_commit_wait(trans);
483 
484 	return 0;
485 }
486 
487 /**
488  * ipa_filter_tuple_zero() - Zero an endpoint's hashed filter tuple
489  * @endpoint:	Endpoint whose filter hash tuple should be zeroed
490  *
491  * Endpoint must be for the AP (not modem) and support filtering. Updates
492  * the filter hash values without changing route ones.
493  */
494 static void ipa_filter_tuple_zero(struct ipa_endpoint *endpoint)
495 {
496 	u32 endpoint_id = endpoint->endpoint_id;
497 	struct ipa *ipa = endpoint->ipa;
498 	const struct reg *reg;
499 	u32 offset;
500 	u32 val;
501 
502 	if (ipa->version < IPA_VERSION_5_0) {
503 		reg = ipa_reg(ipa, ENDP_FILTER_ROUTER_HSH_CFG);
504 
505 		offset = reg_n_offset(reg, endpoint_id);
506 		val = ioread32(endpoint->ipa->reg_virt + offset);
507 
508 		/* Zero all filter-related fields, preserving the rest */
509 		val &= ~reg_fmask(reg, FILTER_HASH_MSK_ALL);
510 	} else {
511 		/* IPA v5.0 separates filter and router cache configuration */
512 		reg = ipa_reg(ipa, ENDP_FILTER_CACHE_CFG);
513 		offset = reg_n_offset(reg, endpoint_id);
514 
515 		/* Zero all filter-related fields */
516 		val = 0;
517 	}
518 
519 	iowrite32(val, endpoint->ipa->reg_virt + offset);
520 }
521 
522 /* Configure a hashed filter table; there is no ipa_filter_deconfig() */
523 static void ipa_filter_config(struct ipa *ipa, bool modem)
524 {
525 	enum gsi_ee_id ee_id = modem ? GSI_EE_MODEM : GSI_EE_AP;
526 	u64 ep_mask = ipa->filtered;
527 
528 	if (!ipa_table_hash_support(ipa))
529 		return;
530 
531 	while (ep_mask) {
532 		u32 endpoint_id = __ffs(ep_mask);
533 		struct ipa_endpoint *endpoint;
534 
535 		ep_mask ^= BIT(endpoint_id);
536 
537 		endpoint = &ipa->endpoint[endpoint_id];
538 		if (endpoint->ee_id == ee_id)
539 			ipa_filter_tuple_zero(endpoint);
540 	}
541 }
542 
543 static bool ipa_route_id_modem(struct ipa *ipa, u32 route_id)
544 {
545 	return route_id < ipa->modem_route_count;
546 }
547 
548 /**
549  * ipa_route_tuple_zero() - Zero a hashed route table entry tuple
550  * @ipa:	IPA pointer
551  * @route_id:	Route table entry whose hash tuple should be zeroed
552  *
553  * Updates the route hash values without changing filter ones.
554  */
555 static void ipa_route_tuple_zero(struct ipa *ipa, u32 route_id)
556 {
557 	const struct reg *reg;
558 	u32 offset;
559 	u32 val;
560 
561 	if (ipa->version < IPA_VERSION_5_0) {
562 		reg = ipa_reg(ipa, ENDP_FILTER_ROUTER_HSH_CFG);
563 		offset = reg_n_offset(reg, route_id);
564 
565 		val = ioread32(ipa->reg_virt + offset);
566 
567 		/* Zero all route-related fields, preserving the rest */
568 		val &= ~reg_fmask(reg, ROUTER_HASH_MSK_ALL);
569 	} else {
570 		/* IPA v5.0 separates filter and router cache configuration */
571 		reg = ipa_reg(ipa, ENDP_ROUTER_CACHE_CFG);
572 		offset = reg_n_offset(reg, route_id);
573 
574 		/* Zero all route-related fields */
575 		val = 0;
576 	}
577 
578 	iowrite32(val, ipa->reg_virt + offset);
579 }
580 
581 /* Configure a hashed route table; there is no ipa_route_deconfig() */
582 static void ipa_route_config(struct ipa *ipa, bool modem)
583 {
584 	u32 route_id;
585 
586 	if (!ipa_table_hash_support(ipa))
587 		return;
588 
589 	for (route_id = 0; route_id < ipa->route_count; route_id++)
590 		if (ipa_route_id_modem(ipa, route_id) == modem)
591 			ipa_route_tuple_zero(ipa, route_id);
592 }
593 
594 /* Configure a filter and route tables; there is no ipa_table_deconfig() */
595 void ipa_table_config(struct ipa *ipa)
596 {
597 	ipa_filter_config(ipa, false);
598 	ipa_filter_config(ipa, true);
599 	ipa_route_config(ipa, false);
600 	ipa_route_config(ipa, true);
601 }
602 
603 /* Verify the sizes of all IPA table filter or routing table memory regions
604  * are valid.  If valid, this records the size of the routing table.
605  */
606 bool ipa_table_mem_valid(struct ipa *ipa, bool filter)
607 {
608 	bool hash_support = ipa_table_hash_support(ipa);
609 	const struct ipa_mem *mem_hashed;
610 	const struct ipa_mem *mem_ipv4;
611 	const struct ipa_mem *mem_ipv6;
612 	u32 count;
613 
614 	/* IPv4 and IPv6 non-hashed tables are expected to be defined and
615 	 * have the same size.  Both must have at least two entries (and
616 	 * would normally have more than that).
617 	 */
618 	mem_ipv4 = ipa_table_mem(ipa, filter, false, false);
619 	if (!mem_ipv4)
620 		return false;
621 
622 	mem_ipv6 = ipa_table_mem(ipa, filter, false, true);
623 	if (!mem_ipv6)
624 		return false;
625 
626 	if (mem_ipv4->size != mem_ipv6->size)
627 		return false;
628 
629 	/* Compute and record the number of entries for each table type */
630 	count = mem_ipv4->size / sizeof(__le64);
631 	if (count < 2)
632 		return false;
633 	if (filter)
634 		ipa->filter_count = count - 1;	/* Filter map in first entry */
635 	else
636 		ipa->route_count = count;
637 
638 	/* Table offset and size must fit in TABLE_INIT command fields */
639 	if (!ipa_cmd_table_init_valid(ipa, mem_ipv4, !filter))
640 		return false;
641 
642 	/* Make sure the regions are big enough */
643 	if (filter) {
644 		/* Filter tables must able to hold the endpoint bitmap plus
645 		 * an entry for each endpoint that supports filtering
646 		 */
647 		if (count < 1 + hweight64(ipa->filtered))
648 			return false;
649 	} else {
650 		/* Routing tables must be able to hold all modem entries,
651 		 * plus at least one entry for the AP.
652 		 */
653 		if (count < ipa->modem_route_count + 1)
654 			return false;
655 	}
656 
657 	/* If hashing is supported, hashed tables are expected to be defined,
658 	 * and have the same size as non-hashed tables.  If hashing is not
659 	 * supported, hashed tables are expected to have zero size (or not
660 	 * be defined).
661 	 */
662 	mem_hashed = ipa_table_mem(ipa, filter, true, false);
663 	if (hash_support) {
664 		if (!mem_hashed || mem_hashed->size != mem_ipv4->size)
665 			return false;
666 	} else {
667 		if (mem_hashed && mem_hashed->size)
668 			return false;
669 	}
670 
671 	/* Same check for IPv6 tables */
672 	mem_hashed = ipa_table_mem(ipa, filter, true, true);
673 	if (hash_support) {
674 		if (!mem_hashed || mem_hashed->size != mem_ipv6->size)
675 			return false;
676 	} else {
677 		if (mem_hashed && mem_hashed->size)
678 			return false;
679 	}
680 
681 	return true;
682 }
683 
684 /* Initialize a coherent DMA allocation containing initialized filter and
685  * route table data.  This is used when initializing or resetting the IPA
686  * filter or route table.
687  *
688  * The first entry in a filter table contains a bitmap indicating which
689  * endpoints contain entries in the table.  In addition to that first entry,
690  * there is a fixed maximum number of entries that follow.  Filter table
691  * entries are 64 bits wide, and (other than the bitmap) contain the DMA
692  * address of a filter rule.  A "zero rule" indicates no filtering, and
693  * consists of 64 bits of zeroes.  When a filter table is initialized (or
694  * reset) its entries are made to refer to the zero rule.
695  *
696  * Each entry in a route table is the DMA address of a routing rule.  For
697  * routing there is also a 64-bit "zero rule" that means no routing, and
698  * when a route table is initialized or reset, its entries are made to refer
699  * to the zero rule.  The zero rule is shared for route and filter tables.
700  *
701  *	     +-------------------+
702  *	 --> |     zero rule     |
703  *	/    |-------------------|
704  *	|    |     filter mask   |
705  *	|\   |-------------------|
706  *	| ---- zero rule address | \
707  *	|\   |-------------------|  |
708  *	| ---- zero rule address |  |	Max IPA filter count
709  *	|    |-------------------|   >	or IPA route count,
710  *	|	      ...	    |	whichever is greater
711  *	 \   |-------------------|  |
712  *	  ---- zero rule address | /
713  *	     +-------------------+
714  */
715 int ipa_table_init(struct ipa *ipa)
716 {
717 	struct device *dev = ipa->dev;
718 	dma_addr_t addr;
719 	__le64 le_addr;
720 	__le64 *virt;
721 	size_t size;
722 	u32 count;
723 
724 	ipa_table_validate_build();
725 
726 	count = max_t(u32, ipa->filter_count, ipa->route_count);
727 
728 	/* The IPA hardware requires route and filter table rules to be
729 	 * aligned on a 128-byte boundary.  We put the "zero rule" at the
730 	 * base of the table area allocated here.  The DMA address returned
731 	 * by dma_alloc_coherent() is guaranteed to be a power-of-2 number
732 	 * of pages, which satisfies the rule alignment requirement.
733 	 */
734 	size = IPA_ZERO_RULE_SIZE + (1 + count) * sizeof(__le64);
735 	virt = dma_alloc_coherent(dev, size, &addr, GFP_KERNEL);
736 	if (!virt)
737 		return -ENOMEM;
738 
739 	ipa->table_virt = virt;
740 	ipa->table_addr = addr;
741 
742 	/* First slot is the zero rule */
743 	*virt++ = 0;
744 
745 	/* Next is the filter table bitmap.  The "soft" bitmap value might
746 	 * need to be converted to the hardware representation by shifting
747 	 * it left one position.  Prior to IPA v5.0, bit 0 repesents global
748 	 * filtering, which is possible but not used.  IPA v5.0+ eliminated
749 	 * that option, so there's no shifting required.
750 	 */
751 	if (ipa->version < IPA_VERSION_5_0)
752 		*virt++ = cpu_to_le64(ipa->filtered << 1);
753 	else
754 		*virt++ = cpu_to_le64(ipa->filtered);
755 
756 	/* All the rest contain the DMA address of the zero rule */
757 	le_addr = cpu_to_le64(addr);
758 	while (count--)
759 		*virt++ = le_addr;
760 
761 	return 0;
762 }
763 
764 void ipa_table_exit(struct ipa *ipa)
765 {
766 	u32 count = max_t(u32, 1 + ipa->filter_count, ipa->route_count);
767 	struct device *dev = ipa->dev;
768 	size_t size;
769 
770 	size = IPA_ZERO_RULE_SIZE + (1 + count) * sizeof(__le64);
771 
772 	dma_free_coherent(dev, size, ipa->table_virt, ipa->table_addr);
773 	ipa->table_addr = 0;
774 	ipa->table_virt = NULL;
775 }
776