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1// SPDX-License-Identifier: GPL-2.02 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 Tables26 *27 * The IPA has tables defined in its local (IPA-resident) memory that define28 * filter and routing rules.  An entry in either of these tables is a little29 * endian 64-bit "slot" that holds the address of a rule definition.  (The30 * 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.  There33 * is normally another set of "hashed" filter and route tables, which are34 * used with a hash of message metadata.  Hashed operation is not supported35 * 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 of38 * an object (such as a route or filter table) in IPA-resident memory must39 * 128-byte aligned.  An object in system memory (such as a route or filter40 * rule) must be at an 8-byte aligned address.  We currently only place41 * route or filter rules in system memory.42 *43 * A rule consists of a contiguous block of 32-bit values terminated with44 * 32 zero bits.  A special "zero entry" rule consisting of 64 zero bits45 * represents "no filtering" or "no routing," and is the reset value for46 * filter or route table rules.47 *48 * Each filter rule is associated with an AP or modem TX endpoint, though49 * not all TX endpoints support filtering.  The first 64-bit slot in a50 * filter table is a bitmap indicating which endpoints have entries in51 * the table.  Each set bit in this bitmap indicates the presence of the52 * address of a filter rule in the memory following the bitmap.  Until IPA53 * v5.0,  the low-order bit (bit 0) in this bitmap represents a special54 * global filter, which applies to all traffic.  Otherwise the position of55 * 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 is58 * removed starting at IPA v5.0.  For IPA v5.0+, the endpoint bitmap59 * position defines the endpoint ID--i.e. if bit 1 is set in the endpoint60 * bitmap, endpoint 1 has a filter rule.  Older versions of IPA represent61 * 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 that66 * implement a filter rule.  So following the endpoint bitmap there67 * will be such an address/entry for each endpoint with a set bit in68 * 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 for72 * endpoints they "own" directly.  Currently the AP does not use the IPA73 * filtering functionality.74 *75 * This diagram shows an example of a filter table with an endpoint76 * bitmap as defined prior to IPA v5.0.77 *78 *                    IPA Filter Table79 *                 ----------------------80 * endpoint bitmap | 0x0000000000000048 | Bits 3 and 6 set (endpoints 2 and 5)81 *                 |--------------------|82 * 1st endpoint    | 0x000123456789abc0 | DMA address for modem endpoint 2 rule83 *                 |--------------------|84 * 2nd endpoint    | 0x000123456789abf0 | DMA address for AP endpoint 5 rule85 *                 |--------------------|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 AP94 * and modem.  The AP initializes all entries in a route table to refer to95 * a "zero entry".  Once initialized, the modem and AP are responsible for96 * 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 Table100 *                 ----------------------101 * 1st modem route | 0x0001234500001100 | DMA address for first route rule102 *                 |--------------------|103 * 2nd modem route | 0x0001234500001140 | DMA address for second route rule104 *                 |--------------------|105 *                          . . .106 *                 |--------------------|107 * Last modem route| 0x0001234500002280 | DMA address for Nth route rule108 *                 |--------------------|109 * 1st AP route    | 0x0001234500001100 | DMA address for route rule (N+1)110 *                 |--------------------|111 * 2nd AP route    | 0x0001234500001140 | DMA address for next route rule112 *                 |--------------------|113 *                          . . .114 *                 |--------------------|115 * Last AP route   | 0x0001234500002280 | DMA address for last route rule116 *                 ----------------------117 */118 119/* Filter or route rules consist of a set of 32-bit values followed by a120 * 32-bit all-zero rule list terminator.  The "zero rule" is simply an121 * 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. */126static void ipa_table_validate_build(void)127{128	/* Filter and route tables contain DMA addresses that refer129	 * to filter or route rules.  But the size of a table entry130	 * is 64 bits regardless of what the size of an AP DMA address131	 * is.  A fixed constant defines the size of an entry, and132	 * code in ipa_table_init() uses a pointer to __le64 to133	 * 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 144static const struct ipa_mem *145ipa_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_HASHED150					: IPA_MEM_V4_FILTER_HASHED151				 : ipv6 ? IPA_MEM_V6_FILTER152					: IPA_MEM_V4_FILTER153			: hashed ? ipv6 ? IPA_MEM_V6_ROUTE_HASHED154					: IPA_MEM_V4_ROUTE_HASHED155				 : ipv6 ? IPA_MEM_V6_ROUTE156					: IPA_MEM_V4_ROUTE;157 158	return ipa_mem_find(ipa, mem_id);159}160 161/* Return true if hashed tables are supported */162bool ipa_table_hash_support(struct ipa *ipa)163{164	return ipa->version != IPA_VERSION_4_2;165}166 167bool 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 */190static 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 205static 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 or230 * modem to refer to the zero entry.  The memory region supplied will be231 * for the IPv4 and IPv6 non-hashed and hashed filter tables.232 */233static int234ipa_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 to267 * update than the maximum number of commands in a transaction.  So268 * we do each table separately.269 */270static 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 the290 * table.  We can update each table with a single command, and we291 * won't exceed the per-transaction command limit.292 * */293static 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 329void 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 349int 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 386static 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_INIT403			       : IPA_CMD_IP_V4_FILTER_INIT404			: ipv6 ? IPA_CMD_IP_V6_ROUTING_INIT405			       : 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 of415		 * entries in the filter table; we also add one more "slot"416		 * to hold the bitmap itself.  The size of the hashed filter417		 * 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 number423		 * 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 454int 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 table463	 *     - One to zero unused entries in the hashed filter table464	 * - 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 table468	 *     - One to zero unused entries in the hashed filter table469	 * 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 tuple489 * @endpoint:	Endpoint whose filter hash tuple should be zeroed490 *491 * Endpoint must be for the AP (not modem) and support filtering. Updates492 * the filter hash values without changing route ones.493 */494static 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() */523static 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 543static 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 tuple550 * @ipa:	IPA pointer551 * @route_id:	Route table entry whose hash tuple should be zeroed552 *553 * Updates the route hash values without changing filter ones.554 */555static 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() */582static 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() */595void 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 regions604 * are valid.  If valid, this records the size of the routing table.605 */606bool 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 and615	 * have the same size.  Both must have at least two entries (and616	 * 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	else636		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 plus645		 * an entry for each endpoint that supports filtering646		 */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 not659	 * supported, hashed tables are expected to have zero size (or not660	 * 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 and685 * route table data.  This is used when initializing or resetting the IPA686 * filter or route table.687 *688 * The first entry in a filter table contains a bitmap indicating which689 * endpoints contain entries in the table.  In addition to that first entry,690 * there is a fixed maximum number of entries that follow.  Filter table691 * entries are 64 bits wide, and (other than the bitmap) contain the DMA692 * address of a filter rule.  A "zero rule" indicates no filtering, and693 * consists of 64 bits of zeroes.  When a filter table is initialized (or694 * 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.  For697 * routing there is also a 64-bit "zero rule" that means no routing, and698 * when a route table is initialized or reset, its entries are made to refer699 * 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 count709 *	|    |-------------------|   >	or IPA route count,710 *	|	      ...	    |	whichever is greater711 *	 \   |-------------------|  |712 *	  ---- zero rule address | /713 *	     +-------------------+714 */715int 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 be729	 * aligned on a 128-byte boundary.  We put the "zero rule" at the730	 * base of the table area allocated here.  The DMA address returned731	 * by dma_alloc_coherent() is guaranteed to be a power-of-2 number732	 * 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 might746	 * need to be converted to the hardware representation by shifting747	 * it left one position.  Prior to IPA v5.0, bit 0 repesents global748	 * filtering, which is possible but not used.  IPA v5.0+ eliminated749	 * 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	else754		*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 764void 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