Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 708 insertions, 0 deletions

diff --git a/drivers/net/ipa/ipa_table.c b/drivers/net/ipa/ipa_table.c
new file mode 100644
index 000000000..cd81dd916
--- /dev/null
+++ b/drivers/net/ipa/ipa_table.c
@@ -0,0 +1,708 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2018-2022 Linaro Ltd.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/bits.h>
+#include <linux/bitops.h>
+#include <linux/bitfield.h>
+#include <linux/io.h>
+#include <linux/build_bug.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+
+#include "ipa.h"
+#include "ipa_version.h"
+#include "ipa_endpoint.h"
+#include "ipa_table.h"
+#include "ipa_reg.h"
+#include "ipa_mem.h"
+#include "ipa_cmd.h"
+#include "gsi.h"
+#include "gsi_trans.h"
+
+/**
+ * DOC: IPA Filter and Route Tables
+ *
+ * The IPA has tables defined in its local (IPA-resident) memory that define
+ * filter and routing rules.  An entry in either of these tables is a little
+ * endian 64-bit "slot" that holds the address of a rule definition.  (The
+ * size of these slots is 64 bits regardless of the host DMA address size.)
+ *
+ * Separate tables (both filter and route) used for IPv4 and IPv6.  There
+ * are normally another set of "hashed" filter and route tables, which are
+ * used with a hash of message metadata.  Hashed operation is not supported
+ * by all IPA hardware (IPA v4.2 doesn't support hashed tables).
+ *
+ * Rules can be in local memory or in DRAM (system memory).  The offset of
+ * an object (such as a route or filter table) in IPA-resident memory must
+ * 128-byte aligned.  An object in system memory (such as a route or filter
+ * rule) must be at an 8-byte aligned address.  We currently only place
+ * route or filter rules in system memory.
+ *
+ * A rule consists of a contiguous block of 32-bit values terminated with
+ * 32 zero bits.  A special "zero entry" rule consisting of 64 zero bits
+ * represents "no filtering" or "no routing," and is the reset value for
+ * filter or route table rules.
+ *
+ * Each filter rule is associated with an AP or modem TX endpoint, though
+ * not all TX endpoints support filtering.  The first 64-bit slot in a
+ * filter table is a bitmap indicating which endpoints have entries in
+ * the table.  The low-order bit (bit 0) in this bitmap represents a
+ * special global filter, which applies to all traffic.  This is not
+ * used in the current code.  Bit 1, if set, indicates that there is an
+ * entry (i.e. slot containing a system address referring to a rule) for
+ * endpoint 0 in the table.  Bit 3, if set, indicates there is an entry
+ * for endpoint 2, and so on.  Space is set aside in IPA local memory to
+ * hold as many filter table entries as might be required, but typically
+ * they are not all used.
+ *
+ * The AP initializes all entries in a filter table to refer to a "zero"
+ * entry.  Once initialized the modem and AP update the entries for
+ * endpoints they "own" directly.  Currently the AP does not use the
+ * IPA filtering functionality.
+ *
+ *                    IPA Filter Table
+ *                 ----------------------
+ * endpoint bitmap | 0x0000000000000048 | Bits 3 and 6 set (endpoints 2 and 5)
+ *                 |--------------------|
+ * 1st endpoint    | 0x000123456789abc0 | DMA address for modem endpoint 2 rule
+ *                 |--------------------|
+ * 2nd endpoint    | 0x000123456789abf0 | DMA address for AP endpoint 5 rule
+ *                 |--------------------|
+ * (unused)        |                    | (Unused space in filter table)
+ *                 |--------------------|
+ *                          . . .
+ *                 |--------------------|
+ * (unused)        |                    | (Unused space in filter table)
+ *                 ----------------------
+ *
+ * The set of available route rules is divided about equally between the AP
+ * and modem.  The AP initializes all entries in a route table to refer to
+ * a "zero entry".  Once initialized, the modem and AP are responsible for
+ * updating their own entries.  All entries in a route table are usable,
+ * though the AP currently does not use the IPA routing functionality.
+ *
+ *                    IPA Route Table
+ *                 ----------------------
+ * 1st modem route | 0x0001234500001100 | DMA address for first route rule
+ *                 |--------------------|
+ * 2nd modem route | 0x0001234500001140 | DMA address for second route rule
+ *                 |--------------------|
+ *                          . . .
+ *                 |--------------------|
+ * Last modem route| 0x0001234500002280 | DMA address for Nth route rule
+ *                 |--------------------|
+ * 1st AP route    | 0x0001234500001100 | DMA address for route rule (N+1)
+ *                 |--------------------|
+ * 2nd AP route    | 0x0001234500001140 | DMA address for next route rule
+ *                 |--------------------|
+ *                          . . .
+ *                 |--------------------|
+ * Last AP route   | 0x0001234500002280 | DMA address for last route rule
+ *                 ----------------------
+ */
+
+/* Assignment of route table entries to the modem and AP */
+#define IPA_ROUTE_MODEM_MIN		0
+#define IPA_ROUTE_AP_MIN		IPA_ROUTE_MODEM_COUNT
+#define IPA_ROUTE_AP_COUNT \
+		(IPA_ROUTE_COUNT_MAX - IPA_ROUTE_MODEM_COUNT)
+
+/* Filter or route rules consist of a set of 32-bit values followed by a
+ * 32-bit all-zero rule list terminator.  The "zero rule" is simply an
+ * all-zero rule followed by the list terminator.
+ */
+#define IPA_ZERO_RULE_SIZE		(2 * sizeof(__le32))
+
+/* Check things that can be validated at build time. */
+static void ipa_table_validate_build(void)
+{
+	/* Filter and route tables contain DMA addresses that refer
+	 * to filter or route rules.  But the size of a table entry
+	 * is 64 bits regardless of what the size of an AP DMA address
+	 * is.  A fixed constant defines the size of an entry, and
+	 * code in ipa_table_init() uses a pointer to __le64 to
+	 * initialize tables.
+	 */
+	BUILD_BUG_ON(sizeof(dma_addr_t) > sizeof(__le64));
+
+	/* A "zero rule" is used to represent no filtering or no routing.
+	 * It is a 64-bit block of zeroed memory.  Code in ipa_table_init()
+	 * assumes that it can be written using a pointer to __le64.
+	 */
+	BUILD_BUG_ON(IPA_ZERO_RULE_SIZE != sizeof(__le64));
+
+	/* Impose a practical limit on the number of routes */
+	BUILD_BUG_ON(IPA_ROUTE_COUNT_MAX > 32);
+	/* The modem must be allotted at least one route table entry */
+	BUILD_BUG_ON(!IPA_ROUTE_MODEM_COUNT);
+	/* But it can't have more than what is available */
+	BUILD_BUG_ON(IPA_ROUTE_MODEM_COUNT > IPA_ROUTE_COUNT_MAX);
+
+}
+
+static bool
+ipa_table_valid_one(struct ipa *ipa, enum ipa_mem_id mem_id, bool route)
+{
+	const struct ipa_mem *mem = ipa_mem_find(ipa, mem_id);
+	struct device *dev = &ipa->pdev->dev;
+	u32 size;
+
+	if (route)
+		size = IPA_ROUTE_COUNT_MAX * sizeof(__le64);
+	else
+		size = (1 + IPA_FILTER_COUNT_MAX) * sizeof(__le64);
+
+	if (!ipa_cmd_table_valid(ipa, mem, route))
+		return false;
+
+	/* mem->size >= size is sufficient, but we'll demand more */
+	if (mem->size == size)
+		return true;
+
+	/* Hashed table regions can be zero size if hashing is not supported */
+	if (ipa_table_hash_support(ipa) && !mem->size)
+		return true;
+
+	dev_err(dev, "%s table region %u size 0x%02x, expected 0x%02x\n",
+		route ? "route" : "filter", mem_id, mem->size, size);
+
+	return false;
+}
+
+/* Verify the filter and route table memory regions are the expected size */
+bool ipa_table_valid(struct ipa *ipa)
+{
+	bool valid;
+
+	valid = ipa_table_valid_one(ipa, IPA_MEM_V4_FILTER, false);
+	valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V6_FILTER, false);
+	valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V4_ROUTE, true);
+	valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V6_ROUTE, true);
+
+	if (!ipa_table_hash_support(ipa))
+		return valid;
+
+	valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V4_FILTER_HASHED,
+					     false);
+	valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V6_FILTER_HASHED,
+					     false);
+	valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V4_ROUTE_HASHED,
+					     true);
+	valid = valid && ipa_table_valid_one(ipa, IPA_MEM_V6_ROUTE_HASHED,
+					     true);
+
+	return valid;
+}
+
+bool ipa_filter_map_valid(struct ipa *ipa, u32 filter_map)
+{
+	struct device *dev = &ipa->pdev->dev;
+	u32 count;
+
+	if (!filter_map) {
+		dev_err(dev, "at least one filtering endpoint is required\n");
+
+		return false;
+	}
+
+	count = hweight32(filter_map);
+	if (count > IPA_FILTER_COUNT_MAX) {
+		dev_err(dev, "too many filtering endpoints (%u, max %u)\n",
+			count, IPA_FILTER_COUNT_MAX);
+
+		return false;
+	}
+
+	return true;
+}
+
+/* Zero entry count means no table, so just return a 0 address */
+static dma_addr_t ipa_table_addr(struct ipa *ipa, bool filter_mask, u16 count)
+{
+	u32 skip;
+
+	if (!count)
+		return 0;
+
+	WARN_ON(count > max_t(u32, IPA_FILTER_COUNT_MAX, IPA_ROUTE_COUNT_MAX));
+
+	/* Skip over the zero rule and possibly the filter mask */
+	skip = filter_mask ? 1 : 2;
+
+	return ipa->table_addr + skip * sizeof(*ipa->table_virt);
+}
+
+static void ipa_table_reset_add(struct gsi_trans *trans, bool filter,
+				u16 first, u16 count, enum ipa_mem_id mem_id)
+{
+	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
+	const struct ipa_mem *mem = ipa_mem_find(ipa, mem_id);
+	dma_addr_t addr;
+	u32 offset;
+	u16 size;
+
+	/* Nothing to do if the table memory region is empty */
+	if (!mem->size)
+		return;
+
+	if (filter)
+		first++;	/* skip over bitmap */
+
+	offset = mem->offset + first * sizeof(__le64);
+	size = count * sizeof(__le64);
+	addr = ipa_table_addr(ipa, false, count);
+
+	ipa_cmd_dma_shared_mem_add(trans, offset, size, addr, true);
+}
+
+/* Reset entries in a single filter table belonging to either the AP or
+ * modem to refer to the zero entry.  The memory region supplied will be
+ * for the IPv4 and IPv6 non-hashed and hashed filter tables.
+ */
+static int
+ipa_filter_reset_table(struct ipa *ipa, enum ipa_mem_id mem_id, bool modem)
+{
+	u32 ep_mask = ipa->filter_map;
+	u32 count = hweight32(ep_mask);
+	struct gsi_trans *trans;
+	enum gsi_ee_id ee_id;
+
+	trans = ipa_cmd_trans_alloc(ipa, count);
+	if (!trans) {
+		dev_err(&ipa->pdev->dev,
+			"no transaction for %s filter reset\n",
+			modem ? "modem" : "AP");
+		return -EBUSY;
+	}
+
+	ee_id = modem ? GSI_EE_MODEM : GSI_EE_AP;
+	while (ep_mask) {
+		u32 endpoint_id = __ffs(ep_mask);
+		struct ipa_endpoint *endpoint;
+
+		ep_mask ^= BIT(endpoint_id);
+
+		endpoint = &ipa->endpoint[endpoint_id];
+		if (endpoint->ee_id != ee_id)
+			continue;
+
+		ipa_table_reset_add(trans, true, endpoint_id, 1, mem_id);
+	}
+
+	gsi_trans_commit_wait(trans);
+
+	return 0;
+}
+
+/* Theoretically, each filter table could have more filter slots to
+ * update than the maximum number of commands in a transaction.  So
+ * we do each table separately.
+ */
+static int ipa_filter_reset(struct ipa *ipa, bool modem)
+{
+	int ret;
+
+	ret = ipa_filter_reset_table(ipa, IPA_MEM_V4_FILTER, modem);
+	if (ret)
+		return ret;
+
+	ret = ipa_filter_reset_table(ipa, IPA_MEM_V6_FILTER, modem);
+	if (ret || !ipa_table_hash_support(ipa))
+		return ret;
+
+	ret = ipa_filter_reset_table(ipa, IPA_MEM_V4_FILTER_HASHED, modem);
+	if (ret)
+		return ret;
+
+	return ipa_filter_reset_table(ipa, IPA_MEM_V6_FILTER_HASHED, modem);
+}
+
+/* The AP routes and modem routes are each contiguous within the
+ * table.  We can update each table with a single command, and we
+ * won't exceed the per-transaction command limit.
+ * */
+static int ipa_route_reset(struct ipa *ipa, bool modem)
+{
+	bool hash_support = ipa_table_hash_support(ipa);
+	struct gsi_trans *trans;
+	u16 first;
+	u16 count;
+
+	trans = ipa_cmd_trans_alloc(ipa, hash_support ? 4 : 2);
+	if (!trans) {
+		dev_err(&ipa->pdev->dev,
+			"no transaction for %s route reset\n",
+			modem ? "modem" : "AP");
+		return -EBUSY;
+	}
+
+	if (modem) {
+		first = IPA_ROUTE_MODEM_MIN;
+		count = IPA_ROUTE_MODEM_COUNT;
+	} else {
+		first = IPA_ROUTE_AP_MIN;
+		count = IPA_ROUTE_AP_COUNT;
+	}
+
+	ipa_table_reset_add(trans, false, first, count, IPA_MEM_V4_ROUTE);
+	ipa_table_reset_add(trans, false, first, count, IPA_MEM_V6_ROUTE);
+
+	if (hash_support) {
+		ipa_table_reset_add(trans, false, first, count,
+				    IPA_MEM_V4_ROUTE_HASHED);
+		ipa_table_reset_add(trans, false, first, count,
+				    IPA_MEM_V6_ROUTE_HASHED);
+	}
+
+	gsi_trans_commit_wait(trans);
+
+	return 0;
+}
+
+void ipa_table_reset(struct ipa *ipa, bool modem)
+{
+	struct device *dev = &ipa->pdev->dev;
+	const char *ee_name;
+	int ret;
+
+	ee_name = modem ? "modem" : "AP";
+
+	/* Report errors, but reset filter and route tables */
+	ret = ipa_filter_reset(ipa, modem);
+	if (ret)
+		dev_err(dev, "error %d resetting filter table for %s\n",
+				ret, ee_name);
+
+	ret = ipa_route_reset(ipa, modem);
+	if (ret)
+		dev_err(dev, "error %d resetting route table for %s\n",
+				ret, ee_name);
+}
+
+int ipa_table_hash_flush(struct ipa *ipa)
+{
+	const struct ipa_reg *reg;
+	struct gsi_trans *trans;
+	u32 offset;
+	u32 val;
+
+	if (!ipa_table_hash_support(ipa))
+		return 0;
+
+	trans = ipa_cmd_trans_alloc(ipa, 1);
+	if (!trans) {
+		dev_err(&ipa->pdev->dev, "no transaction for hash flush\n");
+		return -EBUSY;
+	}
+
+	reg = ipa_reg(ipa, FILT_ROUT_HASH_FLUSH);
+	offset = ipa_reg_offset(reg);
+
+	val = ipa_reg_bit(reg, IPV6_ROUTER_HASH);
+	val |= ipa_reg_bit(reg, IPV6_FILTER_HASH);
+	val |= ipa_reg_bit(reg, IPV4_ROUTER_HASH);
+	val |= ipa_reg_bit(reg, IPV4_FILTER_HASH);
+
+	ipa_cmd_register_write_add(trans, offset, val, val, false);
+
+	gsi_trans_commit_wait(trans);
+
+	return 0;
+}
+
+static void ipa_table_init_add(struct gsi_trans *trans, bool filter,
+			       enum ipa_cmd_opcode opcode,
+			       enum ipa_mem_id mem_id,
+			       enum ipa_mem_id hash_mem_id)
+{
+	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
+	const struct ipa_mem *hash_mem = ipa_mem_find(ipa, hash_mem_id);
+	const struct ipa_mem *mem = ipa_mem_find(ipa, mem_id);
+	dma_addr_t hash_addr;
+	dma_addr_t addr;
+	u32 zero_offset;
+	u16 hash_count;
+	u32 zero_size;
+	u16 hash_size;
+	u16 count;
+	u16 size;
+
+	/* Compute the number of table entries to initialize */
+	if (filter) {
+		/* The number of filtering endpoints determines number of
+		 * entries in the filter table; we also add one more "slot"
+		 * to hold the bitmap itself.  The size of the hashed filter
+		 * table is either the same as the non-hashed one, or zero.
+		 */
+		count = 1 + hweight32(ipa->filter_map);
+		hash_count = hash_mem->size ? count : 0;
+	} else {
+		/* The size of a route table region determines the number
+		 * of entries it has.
+		 */
+		count = mem->size / sizeof(__le64);
+		hash_count = hash_mem->size / sizeof(__le64);
+	}
+	size = count * sizeof(__le64);
+	hash_size = hash_count * sizeof(__le64);
+
+	addr = ipa_table_addr(ipa, filter, count);
+	hash_addr = ipa_table_addr(ipa, filter, hash_count);
+
+	ipa_cmd_table_init_add(trans, opcode, size, mem->offset, addr,
+			       hash_size, hash_mem->offset, hash_addr);
+	if (!filter)
+		return;
+
+	/* Zero the unused space in the filter table */
+	zero_offset = mem->offset + size;
+	zero_size = mem->size - size;
+	ipa_cmd_dma_shared_mem_add(trans, zero_offset, zero_size,
+				   ipa->zero_addr, true);
+	if (!hash_size)
+		return;
+
+	/* Zero the unused space in the hashed filter table */
+	zero_offset = hash_mem->offset + hash_size;
+	zero_size = hash_mem->size - hash_size;
+	ipa_cmd_dma_shared_mem_add(trans, zero_offset, zero_size,
+				   ipa->zero_addr, true);
+}
+
+int ipa_table_setup(struct ipa *ipa)
+{
+	struct gsi_trans *trans;
+
+	/* We will need at most 8 TREs:
+	 * - IPv4:
+	 *     - One for route table initialization (non-hashed and hashed)
+	 *     - One for filter table initialization (non-hashed and hashed)
+	 *     - One to zero unused entries in the non-hashed filter table
+	 *     - One to zero unused entries in the hashed filter table
+	 * - IPv6:
+	 *     - One for route table initialization (non-hashed and hashed)
+	 *     - One for filter table initialization (non-hashed and hashed)
+	 *     - One to zero unused entries in the non-hashed filter table
+	 *     - One to zero unused entries in the hashed filter table
+	 * All platforms support at least 8 TREs in a transaction.
+	 */
+	trans = ipa_cmd_trans_alloc(ipa, 8);
+	if (!trans) {
+		dev_err(&ipa->pdev->dev, "no transaction for table setup\n");
+		return -EBUSY;
+	}
+
+	ipa_table_init_add(trans, false, IPA_CMD_IP_V4_ROUTING_INIT,
+			   IPA_MEM_V4_ROUTE, IPA_MEM_V4_ROUTE_HASHED);
+
+	ipa_table_init_add(trans, false, IPA_CMD_IP_V6_ROUTING_INIT,
+			   IPA_MEM_V6_ROUTE, IPA_MEM_V6_ROUTE_HASHED);
+
+	ipa_table_init_add(trans, true, IPA_CMD_IP_V4_FILTER_INIT,
+			   IPA_MEM_V4_FILTER, IPA_MEM_V4_FILTER_HASHED);
+
+	ipa_table_init_add(trans, true, IPA_CMD_IP_V6_FILTER_INIT,
+			   IPA_MEM_V6_FILTER, IPA_MEM_V6_FILTER_HASHED);
+
+	gsi_trans_commit_wait(trans);
+
+	return 0;
+}
+
+/**
+ * ipa_filter_tuple_zero() - Zero an endpoint's hashed filter tuple
+ * @endpoint:	Endpoint whose filter hash tuple should be zeroed
+ *
+ * Endpoint must be for the AP (not modem) and support filtering. Updates
+ * the filter hash values without changing route ones.
+ */
+static void ipa_filter_tuple_zero(struct ipa_endpoint *endpoint)
+{
+	u32 endpoint_id = endpoint->endpoint_id;
+	struct ipa *ipa = endpoint->ipa;
+	const struct ipa_reg *reg;
+	u32 offset;
+	u32 val;
+
+	reg = ipa_reg(ipa, ENDP_FILTER_ROUTER_HSH_CFG);
+
+	offset = ipa_reg_n_offset(reg, endpoint_id);
+	val = ioread32(endpoint->ipa->reg_virt + offset);
+
+	/* Zero all filter-related fields, preserving the rest */
+	val &= ~ipa_reg_fmask(reg, FILTER_HASH_MSK_ALL);
+
+	iowrite32(val, endpoint->ipa->reg_virt + offset);
+}
+
+/* Configure a hashed filter table; there is no ipa_filter_deconfig() */
+static void ipa_filter_config(struct ipa *ipa, bool modem)
+{
+	enum gsi_ee_id ee_id = modem ? GSI_EE_MODEM : GSI_EE_AP;
+	u32 ep_mask = ipa->filter_map;
+
+	if (!ipa_table_hash_support(ipa))
+		return;
+
+	while (ep_mask) {
+		u32 endpoint_id = __ffs(ep_mask);
+		struct ipa_endpoint *endpoint;
+
+		ep_mask ^= BIT(endpoint_id);
+
+		endpoint = &ipa->endpoint[endpoint_id];
+		if (endpoint->ee_id == ee_id)
+			ipa_filter_tuple_zero(endpoint);
+	}
+}
+
+static bool ipa_route_id_modem(u32 route_id)
+{
+	return route_id >= IPA_ROUTE_MODEM_MIN &&
+		route_id <= IPA_ROUTE_MODEM_MIN + IPA_ROUTE_MODEM_COUNT - 1;
+}
+
+/**
+ * ipa_route_tuple_zero() - Zero a hashed route table entry tuple
+ * @ipa:	IPA pointer
+ * @route_id:	Route table entry whose hash tuple should be zeroed
+ *
+ * Updates the route hash values without changing filter ones.
+ */
+static void ipa_route_tuple_zero(struct ipa *ipa, u32 route_id)
+{
+	const struct ipa_reg *reg;
+	u32 offset;
+	u32 val;
+
+	reg = ipa_reg(ipa, ENDP_FILTER_ROUTER_HSH_CFG);
+	offset = ipa_reg_n_offset(reg, route_id);
+
+	val = ioread32(ipa->reg_virt + offset);
+
+	/* Zero all route-related fields, preserving the rest */
+	val &= ~ipa_reg_fmask(reg, ROUTER_HASH_MSK_ALL);
+
+	iowrite32(val, ipa->reg_virt + offset);
+}
+
+/* Configure a hashed route table; there is no ipa_route_deconfig() */
+static void ipa_route_config(struct ipa *ipa, bool modem)
+{
+	u32 route_id;
+
+	if (!ipa_table_hash_support(ipa))
+		return;
+
+	for (route_id = 0; route_id < IPA_ROUTE_COUNT_MAX; route_id++)
+		if (ipa_route_id_modem(route_id) == modem)
+			ipa_route_tuple_zero(ipa, route_id);
+}
+
+/* Configure a filter and route tables; there is no ipa_table_deconfig() */
+void ipa_table_config(struct ipa *ipa)
+{
+	ipa_filter_config(ipa, false);
+	ipa_filter_config(ipa, true);
+	ipa_route_config(ipa, false);
+	ipa_route_config(ipa, true);
+}
+
+/*
+ * Initialize a coherent DMA allocation containing initialized filter and
+ * route table data.  This is used when initializing or resetting the IPA
+ * filter or route table.
+ *
+ * The first entry in a filter table contains a bitmap indicating which
+ * endpoints contain entries in the table.  In addition to that first entry,
+ * there are at most IPA_FILTER_COUNT_MAX entries that follow.  Filter table
+ * entries are 64 bits wide, and (other than the bitmap) contain the DMA
+ * address of a filter rule.  A "zero rule" indicates no filtering, and
+ * consists of 64 bits of zeroes.  When a filter table is initialized (or
+ * reset) its entries are made to refer to the zero rule.
+ *
+ * Each entry in a route table is the DMA address of a routing rule.  For
+ * routing there is also a 64-bit "zero rule" that means no routing, and
+ * when a route table is initialized or reset, its entries are made to refer
+ * to the zero rule.  The zero rule is shared for route and filter tables.
+ *
+ * Note that the IPA hardware requires a filter or route rule address to be
+ * aligned on a 128 byte boundary.  The coherent DMA buffer we allocate here
+ * has a minimum alignment, and we place the zero rule at the base of that
+ * allocated space.  In ipa_table_init() we verify the minimum DMA allocation
+ * meets our requirement.
+ *
+ *	     +-------------------+
+ *	 --> |     zero rule     |
+ *	/    |-------------------|
+ *	|    |     filter mask   |
+ *	|\   |-------------------|
+ *	| ---- zero rule address | \
+ *	|\   |-------------------|  |
+ *	| ---- zero rule address |  |	IPA_FILTER_COUNT_MAX
+ *	|    |-------------------|   >	or IPA_ROUTE_COUNT_MAX,
+ *	|	      ...	    |	whichever is greater
+ *	 \   |-------------------|  |
+ *	  ---- zero rule address | /
+ *	     +-------------------+
+ */
+int ipa_table_init(struct ipa *ipa)
+{
+	u32 count = max_t(u32, IPA_FILTER_COUNT_MAX, IPA_ROUTE_COUNT_MAX);
+	struct device *dev = &ipa->pdev->dev;
+	dma_addr_t addr;
+	__le64 le_addr;
+	__le64 *virt;
+	size_t size;
+
+	ipa_table_validate_build();
+
+	/* The IPA hardware requires route and filter table rules to be
+	 * aligned on a 128-byte boundary.  We put the "zero rule" at the
+	 * base of the table area allocated here.  The DMA address returned
+	 * by dma_alloc_coherent() is guaranteed to be a power-of-2 number
+	 * of pages, which satisfies the rule alignment requirement.
+	 */
+	size = IPA_ZERO_RULE_SIZE + (1 + count) * sizeof(__le64);
+	virt = dma_alloc_coherent(dev, size, &addr, GFP_KERNEL);
+	if (!virt)
+		return -ENOMEM;
+
+	ipa->table_virt = virt;
+	ipa->table_addr = addr;
+
+	/* First slot is the zero rule */
+	*virt++ = 0;
+
+	/* Next is the filter table bitmap.  The "soft" bitmap value
+	 * must be converted to the hardware representation by shifting
+	 * it left one position.  (Bit 0 repesents global filtering,
+	 * which is possible but not used.)
+	 */
+	*virt++ = cpu_to_le64((u64)ipa->filter_map << 1);
+
+	/* All the rest contain the DMA address of the zero rule */
+	le_addr = cpu_to_le64(addr);
+	while (count--)
+		*virt++ = le_addr;
+
+	return 0;
+}
+
+void ipa_table_exit(struct ipa *ipa)
+{
+	u32 count = max_t(u32, 1 + IPA_FILTER_COUNT_MAX, IPA_ROUTE_COUNT_MAX);
+	struct device *dev = &ipa->pdev->dev;
+	size_t size;
+
+	size = IPA_ZERO_RULE_SIZE + (1 + count) * sizeof(__le64);
+
+	dma_free_coherent(dev, size, ipa->table_virt, ipa->table_addr);
+	ipa->table_addr = 0;
+	ipa->table_virt = NULL;
+}