[10/17] soc: qcom: ipa: IPA endpoints

diff --git a/drivers/net/ipa/ipa_endpoint.c b/drivers/net/ipa/ipa_endpoint.c
new file mode 100644
index 000000000000..1ec5b48da6c8
--- /dev/null
+++ b/drivers/net/ipa/ipa_endpoint.c
@@ -0,0 +1,1706 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2019-2020 Linaro Ltd.
+ */
+
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/bitfield.h>
+#include <linux/if_rmnet.h>
+#include <linux/version.h>
+#include <linux/dma-direction.h>
+
+#include "gsi.h"
+#include "gsi_trans.h"
+#include "ipa.h"
+#include "ipa_data.h"
+#include "ipa_endpoint.h"
+#include "ipa_cmd.h"
+#include "ipa_mem.h"
+#include "ipa_modem.h"
+#include "ipa_table.h"
+#include "ipa_gsi.h"
+
+#define atomic_dec_not_zero(v)	atomic_add_unless((v), -1, 0)
+
+#define IPA_REPLENISH_BATCH	16
+
+#define IPA_RX_BUFFER_SIZE	(PAGE_SIZE << IPA_RX_BUFFER_ORDER)
+#define IPA_RX_BUFFER_ORDER	1	/* 8KB endpoint RX buffers (2 pages) */
+
+/* The amount of RX buffer space consumed by standard skb overhead */
+#define IPA_RX_BUFFER_OVERHEAD	(PAGE_SIZE - SKB_MAX_ORDER(NET_SKB_PAD, 0))
+
+#define IPA_ENDPOINT_STOP_RETRY_MAX		10
+#define IPA_ENDPOINT_STOP_RX_SIZE		1	/* bytes */
+
+#define IPA_ENDPOINT_RESET_AGGR_RETRY_MAX	3
+#define IPA_AGGR_TIME_LIMIT_DEFAULT		1000	/* microseconds */
+
+#define ENDPOINT_STOP_DMA_TIMEOUT		15	/* milliseconds */
+
+/** enum ipa_status_opcode - status element opcode hardware values */
+enum ipa_status_opcode {
+	IPA_STATUS_OPCODE_PACKET		= 0x01,
+	IPA_STATUS_OPCODE_NEW_FRAG_RULE		= 0x02,
+	IPA_STATUS_OPCODE_DROPPED_PACKET	= 0x04,
+	IPA_STATUS_OPCODE_SUSPENDED_PACKET	= 0x08,
+	IPA_STATUS_OPCODE_LOG			= 0x10,
+	IPA_STATUS_OPCODE_DCMP			= 0x20,
+	IPA_STATUS_OPCODE_PACKET_2ND_PASS	= 0x40,
+};
+
+/** enum ipa_status_exception - status element exception type */
+enum ipa_status_exception {
+	/* 0 means no exception */
+	IPA_STATUS_EXCEPTION_DEAGGR		= 0x01,
+	IPA_STATUS_EXCEPTION_IPTYPE		= 0x04,
+	IPA_STATUS_EXCEPTION_PACKET_LENGTH	= 0x08,
+	IPA_STATUS_EXCEPTION_FRAG_RULE_MISS	= 0x10,
+	IPA_STATUS_EXCEPTION_SW_FILT		= 0x20,
+	/* The meaning of the next value depends on whether the IP version */
+	IPA_STATUS_EXCEPTION_NAT		= 0x40,		/* IPv4 */
+	IPA_STATUS_EXCEPTION_IPV6CT		= IPA_STATUS_EXCEPTION_NAT,
+};
+
+/* Status element provided by hardware */
+struct ipa_status {
+	u8 opcode;		/* enum ipa_status_opcode */
+	u8 exception;		/* enum ipa_status_exception */
+	__le16 mask;
+	__le16 pkt_len;
+	u8 endp_src_idx;
+	u8 endp_dst_idx;
+	__le32 metadata;
+	__le32 flags1;
+	__le64 flags2;
+	__le32 flags3;
+	__le32 flags4;
+};
+
+/* Field masks for struct ipa_status structure fields */
+
+#define IPA_STATUS_SRC_IDX_FMASK		GENMASK(4, 0)
+
+#define IPA_STATUS_DST_IDX_FMASK		GENMASK(4, 0)
+
+#define IPA_STATUS_FLAGS1_FLT_LOCAL_FMASK	GENMASK(0, 0)
+#define IPA_STATUS_FLAGS1_FLT_HASH_FMASK	GENMASK(1, 1)
+#define IPA_STATUS_FLAGS1_FLT_GLOBAL_FMASK	GENMASK(2, 2)
+#define IPA_STATUS_FLAGS1_FLT_RET_HDR_FMASK	GENMASK(3, 3)
+#define IPA_STATUS_FLAGS1_FLT_RULE_ID_FMASK	GENMASK(13, 4)
+#define IPA_STATUS_FLAGS1_RT_LOCAL_FMASK	GENMASK(14, 14)
+#define IPA_STATUS_FLAGS1_RT_HASH_FMASK		GENMASK(15, 15)
+#define IPA_STATUS_FLAGS1_UCP_FMASK		GENMASK(16, 16)
+#define IPA_STATUS_FLAGS1_RT_TBL_IDX_FMASK	GENMASK(21, 17)
+#define IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK	GENMASK(31, 22)
+
+#define IPA_STATUS_FLAGS2_NAT_HIT_FMASK		GENMASK_ULL(0, 0)
+#define IPA_STATUS_FLAGS2_NAT_ENTRY_IDX_FMASK	GENMASK_ULL(13, 1)
+#define IPA_STATUS_FLAGS2_NAT_TYPE_FMASK	GENMASK_ULL(15, 14)
+#define IPA_STATUS_FLAGS2_TAG_INFO_FMASK	GENMASK_ULL(63, 16)
+
+#define IPA_STATUS_FLAGS3_SEQ_NUM_FMASK		GENMASK(7, 0)
+#define IPA_STATUS_FLAGS3_TOD_CTR_FMASK		GENMASK(31, 8)
+
+#define IPA_STATUS_FLAGS4_HDR_LOCAL_FMASK	GENMASK(0, 0)
+#define IPA_STATUS_FLAGS4_HDR_OFFSET_FMASK	GENMASK(10, 1)
+#define IPA_STATUS_FLAGS4_FRAG_HIT_FMASK	GENMASK(11, 11)
+#define IPA_STATUS_FLAGS4_FRAG_RULE_FMASK	GENMASK(15, 12)
+#define IPA_STATUS_FLAGS4_HW_SPECIFIC_FMASK	GENMASK(31, 16)
+
+#ifdef IPA_VALIDATE
+
+static void ipa_endpoint_validate_build(void)
+{
+	/* The aggregation byte limit defines the point at which an
+	 * aggregation window will close.  It is programmed into the
+	 * IPA hardware as a number of KB.  We don't use "hard byte
+	 * limit" aggregation, which means that we need to supply
+	 * enough space in a receive buffer to hold a complete MTU
+	 * plus normal skb overhead *after* that aggregation byte
+	 * limit has been crossed.
+	 *
+	 * This check just ensures we don't define a receive buffer
+	 * size that would exceed what we can represent in the field
+	 * that is used to program its size.
+	 */
+	BUILD_BUG_ON(IPA_RX_BUFFER_SIZE >
+		     field_max(AGGR_BYTE_LIMIT_FMASK) * SZ_1K +
+		     IPA_MTU + IPA_RX_BUFFER_OVERHEAD);
+
+	/* I honestly don't know where this requirement comes from.  But
+	 * it holds, and if we someday need to loosen the constraint we
+	 * can try to track it down.
+	 */
+	BUILD_BUG_ON(sizeof(struct ipa_status) % 4);
+}
+
+static bool ipa_endpoint_data_valid_one(struct ipa *ipa, u32 count,
+			    const struct ipa_gsi_endpoint_data *all_data,
+			    const struct ipa_gsi_endpoint_data *data)
+{
+	const struct ipa_gsi_endpoint_data *other_data;
+	struct device *dev = &ipa->pdev->dev;
+	enum ipa_endpoint_name other_name;
+
+	if (ipa_gsi_endpoint_data_empty(data))
+		return true;
+
+	if (!data->toward_ipa) {
+		if (data->endpoint.filter_support) {
+			dev_err(dev, "filtering not supported for "
+					"RX endpoint %u\n",
+				data->endpoint_id);
+			return false;
+		}
+
+		return true;	/* Nothing more to check for RX */
+	}
+
+	if (data->endpoint.config.status_enable) {
+		other_name = data->endpoint.config.tx.status_endpoint;
+		if (other_name >= count) {
+			dev_err(dev, "status endpoint name %u out of range "
+					"for endpoint %u\n",
+				other_name, data->endpoint_id);
+			return false;
+		}
+
+		/* Status endpoint must be defined... */
+		other_data = &all_data[other_name];
+		if (ipa_gsi_endpoint_data_empty(other_data)) {
+			dev_err(dev, "DMA endpoint name %u undefined "
+					"for endpoint %u\n",
+				other_name, data->endpoint_id);
+			return false;
+		}
+
+		/* ...and has to be an RX endpoint... */
+		if (other_data->toward_ipa) {
+			dev_err(dev,
+				"status endpoint for endpoint %u not RX\n",
+				data->endpoint_id);
+			return false;
+		}
+
+		/* ...and if it's to be an AP endpoint... */
+		if (other_data->ee_id == GSI_EE_AP) {
+			/* ...make sure it has status enabled. */
+			if (!other_data->endpoint.config.status_enable) {
+				dev_err(dev,
+					"status not enabled for endpoint %u\n",
+					other_data->endpoint_id);
+				return false;
+			}
+		}
+	}
+
+	if (data->endpoint.config.dma_mode) {
+		other_name = data->endpoint.config.dma_endpoint;
+		if (other_name >= count) {
+			dev_err(dev, "DMA endpoint name %u out of range "
+					"for endpoint %u\n",
+				other_name, data->endpoint_id);
+			return false;
+		}
+
+		other_data = &all_data[other_name];
+		if (ipa_gsi_endpoint_data_empty(other_data)) {
+			dev_err(dev, "DMA endpoint name %u undefined "
+					"for endpoint %u\n",
+				other_name, data->endpoint_id);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static bool ipa_endpoint_data_valid(struct ipa *ipa, u32 count,
+				    const struct ipa_gsi_endpoint_data *data)
+{
+	const struct ipa_gsi_endpoint_data *dp = data;
+	struct device *dev = &ipa->pdev->dev;
+	enum ipa_endpoint_name name;
+
+	ipa_endpoint_validate_build();
+
+	if (count > IPA_ENDPOINT_COUNT) {
+		dev_err(dev, "too many endpoints specified (%u > %u)\n",
+			count, IPA_ENDPOINT_COUNT);
+		return false;
+	}
+
+	/* Make sure needed endpoints have defined data */
+	if (ipa_gsi_endpoint_data_empty(&data[IPA_ENDPOINT_AP_COMMAND_TX])) {
+		dev_err(dev, "command TX endpoint not defined\n");
+		return false;
+	}
+	if (ipa_gsi_endpoint_data_empty(&data[IPA_ENDPOINT_AP_LAN_RX])) {
+		dev_err(dev, "LAN RX endpoint not defined\n");
+		return false;
+	}
+	if (ipa_gsi_endpoint_data_empty(&data[IPA_ENDPOINT_AP_MODEM_TX])) {
+		dev_err(dev, "AP->modem TX endpoint not defined\n");
+		return false;
+	}
+	if (ipa_gsi_endpoint_data_empty(&data[IPA_ENDPOINT_AP_MODEM_RX])) {
+		dev_err(dev, "AP<-modem RX endpoint not defined\n");
+		return false;
+	}
+
+	for (name = 0; name < count; name++, dp++)
+		if (!ipa_endpoint_data_valid_one(ipa, count, data, dp))
+			return false;
+
+	return true;
+}
+
+#else /* !IPA_VALIDATE */
+
+static bool ipa_endpoint_data_valid(struct ipa *ipa, u32 count,
+				    const struct ipa_gsi_endpoint_data *data)
+{
+	return true;
+}
+
+#endif /* !IPA_VALIDATE */
+
+/* Allocate a transaction to use on a non-command endpoint */
+static struct gsi_trans *ipa_endpoint_trans_alloc(struct ipa_endpoint *endpoint,
+						  u32 tre_count)
+{
+	struct gsi *gsi = &endpoint->ipa->gsi;
+	u32 channel_id = endpoint->channel_id;
+	enum dma_data_direction direction;
+
+	direction = endpoint->toward_ipa ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+	return gsi_channel_trans_alloc(gsi, channel_id, tre_count, direction);
+}
+
+/* suspend_delay represents suspend for RX, delay for TX endpoints.
+ * Note that suspend is not supported starting with IPA v4.0.
+ */
+static int
+ipa_endpoint_init_ctrl(struct ipa_endpoint *endpoint, bool suspend_delay)
+{
+	u32 offset = IPA_REG_ENDP_INIT_CTRL_N_OFFSET(endpoint->endpoint_id);
+	struct ipa *ipa = endpoint->ipa;
+	u32 mask;
+	u32 val;
+
+	/* assert(ipa->version == IPA_VERSION_3_5_1 */
+	mask = endpoint->toward_ipa ? ENDP_DELAY_FMASK : ENDP_SUSPEND_FMASK;
+
+	val = ioread32(ipa->reg_virt + offset);
+	if (suspend_delay == !!(val & mask))
+		return -EALREADY;	/* Already set to desired state */
+
+	val ^= mask;
+	iowrite32(val, ipa->reg_virt + offset);
+
+	return 0;
+}
+
+/* Enable or disable delay or suspend mode on all modem endpoints */
+void ipa_endpoint_modem_pause_all(struct ipa *ipa, bool enable)
+{
+	bool support_suspend;
+	u32 endpoint_id;
+
+	/* DELAY mode doesn't work right on IPA v4.2 */
+	if (ipa->version == IPA_VERSION_4_2)
+		return;
+
+	/* Only IPA v3.5.1 supports SUSPEND mode on RX endpoints */
+	support_suspend = ipa->version == IPA_VERSION_3_5_1;
+
+	for (endpoint_id = 0; endpoint_id < IPA_ENDPOINT_MAX; endpoint_id++) {
+		struct ipa_endpoint *endpoint = &ipa->endpoint[endpoint_id];
+
+		if (endpoint->ee_id != GSI_EE_MODEM)
+			continue;
+
+		/* Set TX delay mode, or for IPA v3.5.1 RX suspend mode */
+		if (endpoint->toward_ipa || support_suspend)
+			(void)ipa_endpoint_init_ctrl(endpoint, enable);
+	}
+}
+
+/* Reset all modem endpoints to use the default exception endpoint */
+int ipa_endpoint_modem_exception_reset_all(struct ipa *ipa)
+{
+	u32 initialized = ipa->initialized;
+	struct gsi_trans *trans;
+	u32 count;
+
+	/* We need one command per modem TX endpoint.  We can get an upper
+	 * bound on that by assuming all initialized endpoints are modem->IPA.
+	 * That won't happen, and we could be more precise, but this is fine
+	 * for now.  We need to end the transactio with a "tag process."
+	 */
+	count = hweight32(initialized) + ipa_cmd_tag_process_count();
+	trans = ipa_cmd_trans_alloc(ipa, count);
+	if (!trans) {
+		dev_err(&ipa->pdev->dev,
+			"no transaction to reset modem exception endpoints\n");
+		return -EBUSY;
+	}
+
+	while (initialized) {
+		u32 endpoint_id = __ffs(initialized);
+		struct ipa_endpoint *endpoint;
+		u32 offset;
+
+		initialized ^= BIT(endpoint_id);
+
+		/* We only reset modem TX endpoints */
+		endpoint = &ipa->endpoint[endpoint_id];
+		if (!(endpoint->ee_id == GSI_EE_MODEM && endpoint->toward_ipa))
+			continue;
+
+		offset = IPA_REG_ENDP_STATUS_N_OFFSET(endpoint_id);
+
+		/* Value written is 0, and all bits are updated.  That
+		 * means status is disabled on the endpoint, and as a
+		 * result all other fields in the register are ignored.
+		 */
+		ipa_cmd_register_write_add(trans, offset, 0, ~0, false);
+	}
+
+	ipa_cmd_tag_process_add(trans);
+
+	/* XXX This should have a 1 second timeout */
+	gsi_trans_commit_wait(trans);
+
+	return 0;
+}
+
+static void ipa_endpoint_init_cfg(struct ipa_endpoint *endpoint)
+{
+	u32 offset = IPA_REG_ENDP_INIT_CFG_N_OFFSET(endpoint->endpoint_id);
+	u32 val = 0;
+
+	/* FRAG_OFFLOAD_EN is 0 */
+	if (endpoint->data->checksum) {
+		if (endpoint->toward_ipa) {
+			u32 checksum_offset;
+
+			val |= u32_encode_bits(IPA_CS_OFFLOAD_UL,
+					       CS_OFFLOAD_EN_FMASK);
+			/* Checksum header offset is in 4-byte units */
+			checksum_offset = sizeof(struct rmnet_map_header);
+			checksum_offset /= sizeof(u32);
+			val |= u32_encode_bits(checksum_offset,
+					       CS_METADATA_HDR_OFFSET_FMASK);
+		} else {
+			val |= u32_encode_bits(IPA_CS_OFFLOAD_DL,
+					       CS_OFFLOAD_EN_FMASK);
+		}
+	} else {
+		val |= u32_encode_bits(IPA_CS_OFFLOAD_NONE,
+				       CS_OFFLOAD_EN_FMASK);
+	}
+	/* CS_GEN_QMB_MASTER_SEL is 0 */
+
+	iowrite32(val, endpoint->ipa->reg_virt + offset);
+}
+
+static void ipa_endpoint_init_hdr(struct ipa_endpoint *endpoint)
+{
+	u32 offset = IPA_REG_ENDP_INIT_HDR_N_OFFSET(endpoint->endpoint_id);
+	u32 val = 0;
+
+	if (endpoint->data->qmap) {
+		size_t header_size = sizeof(struct rmnet_map_header);
+
+		if (endpoint->toward_ipa && endpoint->data->checksum)
+			header_size += sizeof(struct rmnet_map_ul_csum_header);
+
+		val |= u32_encode_bits(header_size, HDR_LEN_FMASK);
+		/* metadata is the 4 byte rmnet_map header itself */
+		val |= HDR_OFST_METADATA_VALID_FMASK;
+		val |= u32_encode_bits(0, HDR_OFST_METADATA_FMASK);
+		/* HDR_ADDITIONAL_CONST_LEN is 0; (IPA->AP only) */
+		if (!endpoint->toward_ipa) {
+			u32 size_offset = offsetof(struct rmnet_map_header,
+						   pkt_len);
+
+			val |= HDR_OFST_PKT_SIZE_VALID_FMASK;
+			val |= u32_encode_bits(size_offset,
+					       HDR_OFST_PKT_SIZE_FMASK);
+		}
+		/* HDR_A5_MUX is 0 */
+		/* HDR_LEN_INC_DEAGG_HDR is 0 */
+		/* HDR_METADATA_REG_VALID is 0; (AP->IPA only) */
+	}
+
+	iowrite32(val, endpoint->ipa->reg_virt + offset);
+}
+
+static void ipa_endpoint_init_hdr_ext(struct ipa_endpoint *endpoint)
+{
+	u32 offset = IPA_REG_ENDP_INIT_HDR_EXT_N_OFFSET(endpoint->endpoint_id);
+	u32 pad_align = endpoint->data->rx.pad_align;
+	u32 val = 0;
+
+	val |= HDR_ENDIANNESS_FMASK;		/* big endian */
+	val |= HDR_TOTAL_LEN_OR_PAD_VALID_FMASK;
+	/* HDR_TOTAL_LEN_OR_PAD is 0 (pad, not total_len) */
+	/* HDR_PAYLOAD_LEN_INC_PADDING is 0 */
+	/* HDR_TOTAL_LEN_OR_PAD_OFFSET is 0 */
+	if (!endpoint->toward_ipa)
+		val |= u32_encode_bits(pad_align, HDR_PAD_TO_ALIGNMENT_FMASK);
+
+	iowrite32(val, endpoint->ipa->reg_virt + offset);
+}
+
+/**
+ * Generate a metadata mask value that will select only the mux_id
+ * field in an rmnet_map header structure.  The mux_id is at offset
+ * 1 byte from the beginning of the structure, but the metadata
+ * value is treated as a 4-byte unit.  So this mask must be computed
+ * with endianness in mind.  Note that ipa_endpoint_init_hdr_metadata_mask()
+ * will convert this value to the proper byte order.
+ *
+ * Marked __always_inline because this is really computing a
+ * constant value.
+ */
+static __always_inline __be32 ipa_rmnet_mux_id_metadata_mask(void)
+{
+	size_t mux_id_offset = offsetof(struct rmnet_map_header, mux_id);
+	u32 mux_id_mask = 0;
+	u8 *bytes;
+
+	bytes = (u8 *)&mux_id_mask;
+	bytes[mux_id_offset] = 0xff;	/* mux_id is 1 byte */
+
+	return cpu_to_be32(mux_id_mask);
+}
+
+static void ipa_endpoint_init_hdr_metadata_mask(struct ipa_endpoint *endpoint)
+{
+	u32 endpoint_id = endpoint->endpoint_id;
+	u32 val = 0;
+	u32 offset;
+
+	offset = IPA_REG_ENDP_INIT_HDR_METADATA_MASK_N_OFFSET(endpoint_id);
+
+	if (!endpoint->toward_ipa && endpoint->data->qmap)
+		val = ipa_rmnet_mux_id_metadata_mask();
+
+	iowrite32(val, endpoint->ipa->reg_virt + offset);
+}
+
+static void ipa_endpoint_init_mode(struct ipa_endpoint *endpoint)
+{
+	u32 offset = IPA_REG_ENDP_INIT_MODE_N_OFFSET(endpoint->endpoint_id);
+	u32 val;
+
+	if (endpoint->toward_ipa && endpoint->data->dma_mode) {
+		enum ipa_endpoint_name name = endpoint->data->dma_endpoint;
+		u32 dma_endpoint_id;
+
+		dma_endpoint_id = endpoint->ipa->name_map[name]->endpoint_id;
+
+		val = u32_encode_bits(IPA_DMA, MODE_FMASK);
+		val |= u32_encode_bits(dma_endpoint_id, DEST_PIPE_INDEX_FMASK);
+	} else {
+		val = u32_encode_bits(IPA_BASIC, MODE_FMASK);
+	}
+	/* Other bitfields unspecified (and 0) */
+
+	iowrite32(val, endpoint->ipa->reg_virt + offset);
+}
+
+/* Compute the aggregation size value to use for a given buffer size */
+static u32 ipa_aggr_size_kb(u32 rx_buffer_size)
+{
+	/* We don't use "hard byte limit" aggregation, so we define the
+	 * aggregation limit such that our buffer has enough space *after*
+	 * that limit to receive a full MTU of data, plus overhead.
+	 */
+	rx_buffer_size -= IPA_MTU + IPA_RX_BUFFER_OVERHEAD;
+
+	return rx_buffer_size / SZ_1K;
+}
+
+static void ipa_endpoint_init_aggr(struct ipa_endpoint *endpoint)
+{
+	u32 offset = IPA_REG_ENDP_INIT_AGGR_N_OFFSET(endpoint->endpoint_id);
+	u32 val = 0;
+
+	if (endpoint->data->aggregation) {
+		if (!endpoint->toward_ipa) {
+			u32 aggr_size = ipa_aggr_size_kb(IPA_RX_BUFFER_SIZE);
+			u32 limit;
+
+			val |= u32_encode_bits(IPA_ENABLE_AGGR, AGGR_EN_FMASK);
+			val |= u32_encode_bits(IPA_GENERIC, AGGR_TYPE_FMASK);
+			val |= u32_encode_bits(aggr_size,
+					       AGGR_BYTE_LIMIT_FMASK);
+			limit = IPA_AGGR_TIME_LIMIT_DEFAULT;
+			val |= u32_encode_bits(limit / IPA_AGGR_GRANULARITY,
+					       AGGR_TIME_LIMIT_FMASK);
+			val |= u32_encode_bits(0, AGGR_PKT_LIMIT_FMASK);
+			if (endpoint->data->rx.aggr_close_eof)
+				val |= AGGR_SW_EOF_ACTIVE_FMASK;
+			/* AGGR_HARD_BYTE_LIMIT_ENABLE is 0 */
+		} else {
+			val |= u32_encode_bits(IPA_ENABLE_DEAGGR,
+					       AGGR_EN_FMASK);
+			val |= u32_encode_bits(IPA_QCMAP, AGGR_TYPE_FMASK);
+			/* other fields ignored */
+		}
+		/* AGGR_FORCE_CLOSE is 0 */
+	} else {
+		val |= u32_encode_bits(IPA_BYPASS_AGGR, AGGR_EN_FMASK);
+		/* other fields ignored */
+	}
+
+	iowrite32(val, endpoint->ipa->reg_virt + offset);
+}
+
+/* A return value of 0 indicates an error */
+static u32 ipa_reg_init_hol_block_timer_val(struct ipa *ipa, u32 microseconds)
+{
+	u32 scale;
+	u32 base;
+	u32 val;
+
+	if (!microseconds)
+		return 0;	/* invalid delay */
+
+	/* Timer is represented in units of clock ticks. */
+	if (ipa->version < IPA_VERSION_4_2)
+		return microseconds;	/* XXX Needs to be computed */
+
+	/* IPA v4.2 represents the tick count as base * scale */
+	scale = 1;			/* XXX Needs to be computed */
+	if (scale > field_max(SCALE_FMASK))
+		return 0;		/* scale too big */
+
+	base = DIV_ROUND_CLOSEST(microseconds, scale);
+	if (base > field_max(BASE_VALUE_FMASK))
+		return 0;		/* microseconds too big */
+
+	val = u32_encode_bits(scale, SCALE_FMASK);
+	val |= u32_encode_bits(base, BASE_VALUE_FMASK);
+
+	return val;
+}
+
+static int ipa_endpoint_init_hol_block_timer(struct ipa_endpoint *endpoint,
+					     u32 microseconds)
+{
+	u32 endpoint_id = endpoint->endpoint_id;
+	struct ipa *ipa = endpoint->ipa;
+	u32 offset;
+	u32 val;
+
+	/* XXX We'll fix this when the register definition is clear */
+	if (microseconds) {
+		struct device *dev = &ipa->pdev->dev;
+
+		dev_err(dev, "endpoint %u non-zero HOLB period (ignoring)\n",
+			endpoint_id);
+		microseconds = 0;
+	}
+
+	if (microseconds) {
+		val = ipa_reg_init_hol_block_timer_val(ipa, microseconds);
+		if (!val)
+			return -EINVAL;
+	} else {
+		val = 0;	/* timeout is immediate */
+	}
+	offset = IPA_REG_ENDP_INIT_HOL_BLOCK_TIMER_N_OFFSET(endpoint_id);
+	iowrite32(val, ipa->reg_virt + offset);
+
+	return 0;
+}
+
+static void
+ipa_endpoint_init_hol_block_enable(struct ipa_endpoint *endpoint, bool enable)
+{
+	u32 endpoint_id = endpoint->endpoint_id;
+	u32 offset;
+	u32 val;
+
+	val = u32_encode_bits(enable ? 1 : 0, HOL_BLOCK_EN_FMASK);
+	offset = IPA_REG_ENDP_INIT_HOL_BLOCK_EN_N_OFFSET(endpoint_id);
+	iowrite32(val, endpoint->ipa->reg_virt + offset);
+}
+
+void ipa_endpoint_modem_hol_block_clear_all(struct ipa *ipa)
+{
+	u32 i;
+
+	for (i = 0; i < IPA_ENDPOINT_MAX; i++) {
+		struct ipa_endpoint *endpoint = &ipa->endpoint[i];
+
+		if (endpoint->ee_id != GSI_EE_MODEM)
+			continue;
+
+		(void)ipa_endpoint_init_hol_block_timer(endpoint, 0);
+		ipa_endpoint_init_hol_block_enable(endpoint, true);
+	}
+}
+
+static void ipa_endpoint_init_deaggr(struct ipa_endpoint *endpoint)
+{
+	u32 offset = IPA_REG_ENDP_INIT_DEAGGR_N_OFFSET(endpoint->endpoint_id);
+	u32 val = 0;
+
+	/* DEAGGR_HDR_LEN is 0 */
+	/* PACKET_OFFSET_VALID is 0 */
+	/* PACKET_OFFSET_LOCATION is ignored (not valid) */
+	/* MAX_PACKET_LEN is 0 (not enforced) */
+
+	iowrite32(val, endpoint->ipa->reg_virt + offset);
+}
+
+static void ipa_endpoint_init_seq(struct ipa_endpoint *endpoint)
+{
+	u32 offset = IPA_REG_ENDP_INIT_SEQ_N_OFFSET(endpoint->endpoint_id);
+	u32 seq_type = endpoint->seq_type;
+	u32 val = 0;
+
+	val |= u32_encode_bits(seq_type & 0xf, HPS_SEQ_TYPE_FMASK);
+	val |= u32_encode_bits((seq_type >> 4) & 0xf, DPS_SEQ_TYPE_FMASK);
+	/* HPS_REP_SEQ_TYPE is 0 */
+	/* DPS_REP_SEQ_TYPE is 0 */
+
+	iowrite32(val, endpoint->ipa->reg_virt + offset);
+}
+
+/**
+ * ipa_endpoint_skb_tx() - Transmit a socket buffer
+ * @endpoint:	Endpoint pointer
+ * @skb:	Socket buffer to send
+ *
+ * Returns:	0 if successful, or a negative error code
+ */
+int ipa_endpoint_skb_tx(struct ipa_endpoint *endpoint, struct sk_buff *skb)
+{
+	struct gsi_trans *trans;
+	u32 nr_frags;
+	int ret;
+
+	/* Make sure source endpoint's TLV FIFO has enough entries to
+	 * hold the linear portion of the skb and all its fragments.
+	 * If not, see if we can linearize it before giving up.
+	 */
+	nr_frags = skb_shinfo(skb)->nr_frags;
+	if (1 + nr_frags > endpoint->trans_tre_max) {
+		if (skb_linearize(skb))
+			return -E2BIG;
+		nr_frags = 0;
+	}
+
+	trans = ipa_endpoint_trans_alloc(endpoint, 1 + nr_frags);
+	if (!trans)
+		return -EBUSY;
+
+	ret = gsi_trans_skb_add(trans, skb);
+	if (ret)
+		goto err_trans_free;
+	trans->data = skb;	/* transaction owns skb now */
+
+	gsi_trans_commit(trans, !netdev_xmit_more());
+
+	return 0;
+
+err_trans_free:
+	gsi_trans_free(trans);
+
+	return -ENOMEM;
+}
+
+static void ipa_endpoint_status(struct ipa_endpoint *endpoint)
+{
+	u32 endpoint_id = endpoint->endpoint_id;
+	struct ipa *ipa = endpoint->ipa;
+	u32 val = 0;
+	u32 offset;
+
+	offset = IPA_REG_ENDP_STATUS_N_OFFSET(endpoint_id);
+
+	if (endpoint->data->status_enable) {
+		val |= STATUS_EN_FMASK;
+		if (endpoint->toward_ipa) {
+			enum ipa_endpoint_name name;
+			u32 status_endpoint_id;
+
+			name = endpoint->data->tx.status_endpoint;
+			status_endpoint_id = ipa->name_map[name]->endpoint_id;
+
+			val |= u32_encode_bits(status_endpoint_id,
+					       STATUS_ENDP_FMASK);
+		}
+		/* STATUS_LOCATION is 0 (status element precedes packet) */
+		/* The next field is present for IPA v4.0 and above */
+		/* STATUS_PKT_SUPPRESS_FMASK is 0 */
+	}
+
+	iowrite32(val, ipa->reg_virt + offset);
+}
+
+static int ipa_endpoint_replenish_one(struct ipa_endpoint *endpoint)
+{
+	struct gsi_trans *trans;
+	bool doorbell = false;
+	struct page *page;
+	u32 offset;
+	u32 len;
+	int ret;
+
+	page = dev_alloc_pages(IPA_RX_BUFFER_ORDER);
+	if (!page)
+		return -ENOMEM;
+
+	trans = ipa_endpoint_trans_alloc(endpoint, 1);
+	if (!trans)
+		goto err_free_pages;
+
+	/* Offset the buffer to make space for skb headroom */
+	offset = NET_SKB_PAD;
+	len = IPA_RX_BUFFER_SIZE - offset;
+
+	ret = gsi_trans_page_add(trans, page, len, offset);
+	if (ret)
+		goto err_trans_free;
+	trans->data = page;	/* transaction owns page now */
+
+	if (++endpoint->replenish_ready == IPA_REPLENISH_BATCH) {
+		doorbell = true;
+		endpoint->replenish_ready = 0;
+	}
+
+	gsi_trans_commit(trans, doorbell);
+
+	return 0;
+
+err_trans_free:
+	gsi_trans_free(trans);
+err_free_pages:
+	__free_pages(page, IPA_RX_BUFFER_ORDER);
+
+	return -ENOMEM;
+}
+
+/**
+ * ipa_endpoint_replenish() - Replenish the Rx packets cache.
+ *
+ * Allocate RX packet wrapper structures with maximal socket buffers
+ * for an endpoint.  These are supplied to the hardware, which fills
+ * them with incoming data.
+ */
+static void ipa_endpoint_replenish(struct ipa_endpoint *endpoint, bool add_one)
+{
+	struct gsi *gsi;
+	u32 backlog;
+
+	if (!endpoint->replenish_enabled) {
+		if (add_one)
+			atomic_inc(&endpoint->replenish_saved);
+		return;
+	}
+
+	if (add_one)
+		atomic_inc(&endpoint->replenish_backlog);
+
+	while (atomic_dec_not_zero(&endpoint->replenish_backlog))
+		if (ipa_endpoint_replenish_one(endpoint))
+			goto try_again_later;
+
+	return;
+
+try_again_later:
+	/* The last one didn't succeed, so fix the backlog */
+	backlog = atomic_inc_return(&endpoint->replenish_backlog);
+
+	/* Whenever a receive buffer transaction completes we'll try to
+	 * replenish again.  It's unlikely, but if we fail to supply even
+	 * one buffer, nothing will trigger another replenish attempt.
+	 * Receive buffer transactions use one TRE, so schedule work to
+	 * try replenishing again if our backlog is *all* available TREs.
+	 */
+	gsi = &endpoint->ipa->gsi;
+	if (backlog == gsi_channel_tre_max(gsi, endpoint->channel_id))
+		schedule_delayed_work(&endpoint->replenish_work,
+				      msecs_to_jiffies(1));
+}
+
+static void ipa_endpoint_replenish_enable(struct ipa_endpoint *endpoint)
+{
+	struct gsi *gsi = &endpoint->ipa->gsi;
+	u32 max_backlog;
+	u32 saved;
+
+	endpoint->replenish_enabled = true;
+	while ((saved = atomic_xchg(&endpoint->replenish_saved, 0)))
+		atomic_add(saved, &endpoint->replenish_backlog);
+
+	/* Start replenishing if hardware currently has no buffers */
+	max_backlog = gsi_channel_tre_max(gsi, endpoint->channel_id);
+	if (atomic_read(&endpoint->replenish_backlog) == max_backlog) {
+		ipa_endpoint_replenish(endpoint, false);
+		return;
+	}
+}
+
+static void ipa_endpoint_replenish_disable(struct ipa_endpoint *endpoint)
+{
+	u32 backlog;
+
+	endpoint->replenish_enabled = false;
+	while ((backlog = atomic_xchg(&endpoint->replenish_backlog, 0)))
+		atomic_add(backlog, &endpoint->replenish_saved);
+}
+
+static void ipa_endpoint_replenish_work(struct work_struct *work)
+{
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct ipa_endpoint *endpoint;
+
+	endpoint = container_of(dwork, struct ipa_endpoint, replenish_work);
+
+	ipa_endpoint_replenish(endpoint, false);
+}
+
+static void ipa_endpoint_skb_copy(struct ipa_endpoint *endpoint,
+				  void *data, u32 len, u32 extra)
+{
+	struct sk_buff *skb;
+
+	skb = __dev_alloc_skb(len, GFP_ATOMIC);
+	if (skb) {
+		skb_put(skb, len);
+		memcpy(skb->data, data, len);
+		skb->truesize += extra;
+	}
+
+	/* Now receive it, or drop it if there's no netdev */
+	if (endpoint->netdev)
+		ipa_modem_skb_rx(endpoint->netdev, skb);
+	else if (skb)
+		dev_kfree_skb_any(skb);
+}
+
+static bool ipa_endpoint_skb_build(struct ipa_endpoint *endpoint,
+				   struct page *page, u32 len)
+{
+	struct sk_buff *skb;
+
+	/* Nothing to do if there's no netdev */
+	if (!endpoint->netdev)
+		return false;
+
+	/* assert(len <= SKB_WITH_OVERHEAD(IPA_RX_BUFFER_SIZE-NET_SKB_PAD)); */
+	skb = build_skb(page_address(page), IPA_RX_BUFFER_SIZE);
+	if (skb) {
+		/* Reserve the headroom and account for the data */
+		skb_reserve(skb, NET_SKB_PAD);
+		skb_put(skb, len);
+	}
+
+	/* Receive the buffer (or record drop if unable to build it) */
+	ipa_modem_skb_rx(endpoint->netdev, skb);
+
+	return skb != NULL;
+}
+
+/* The format of a packet status element is the same for several status
+ * types (opcodes).  The NEW_FRAG_RULE, LOG, DCMP (decompression) types
+ * aren't currently supported
+ */
+static bool ipa_status_format_packet(enum ipa_status_opcode opcode)
+{
+	switch (opcode) {
+	case IPA_STATUS_OPCODE_PACKET:
+	case IPA_STATUS_OPCODE_DROPPED_PACKET:
+	case IPA_STATUS_OPCODE_SUSPENDED_PACKET:
+	case IPA_STATUS_OPCODE_PACKET_2ND_PASS:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool ipa_endpoint_status_skip(struct ipa_endpoint *endpoint,
+				     const struct ipa_status *status)
+{
+	u32 endpoint_id;
+
+	if (!ipa_status_format_packet(status->opcode))
+		return true;
+	if (!status->pkt_len)
+		return true;
+	endpoint_id = u32_get_bits(status->endp_dst_idx,
+				   IPA_STATUS_DST_IDX_FMASK);
+	if (endpoint_id != endpoint->endpoint_id)
+		return true;
+
+	return false;	/* Don't skip this packet, process it */
+}
+
+/* Return whether the status indicates the packet should be dropped */
+static bool ipa_status_drop_packet(const struct ipa_status *status)
+{
+	u32 val;
+
+	/* Deaggregation exceptions we drop; others we consume */
+	if (status->exception)
+		return status->exception == IPA_STATUS_EXCEPTION_DEAGGR;
+
+	/* Drop the packet if it fails to match a routing rule; otherwise no */
+	val = le32_get_bits(status->flags1, IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);
+
+	return val == field_max(IPA_STATUS_FLAGS1_RT_RULE_ID_FMASK);
+}
+
+static void ipa_endpoint_status_parse(struct ipa_endpoint *endpoint,
+				      struct page *page, u32 total_len)
+{
+	void *data = page_address(page) + NET_SKB_PAD;
+	u32 unused = IPA_RX_BUFFER_SIZE - total_len;
+	u32 resid = total_len;
+
+	while (resid) {
+		const struct ipa_status *status = data;
+		u32 align;
+		u32 len;
+
+		if (resid < sizeof(*status)) {
+			dev_err(&endpoint->ipa->pdev->dev,
+				"short message (%u bytes < %zu byte status)\n",
+				resid, sizeof(*status));
+			break;
+		}
+
+		/* Skip over status packets that lack packet data */
+		if (ipa_endpoint_status_skip(endpoint, status)) {
+			data += sizeof(*status);
+			resid -= sizeof(*status);
+			continue;
+		}
+
+		/* Compute the amount of buffer space consumed by the
+		 * packet, including the status element.  If the hardware
+		 * is configured to pad packet data to an aligned boundary,
+		 * account for that.  And if checksum offload is is enabled
+		 * a trailer containing computed checksum information will
+		 * be appended.
+		 */
+		align = endpoint->data->rx.pad_align ? : 1;
+		len = le16_to_cpu(status->pkt_len);
+		len = sizeof(*status) + ALIGN(len, align);
+		if (endpoint->data->checksum)
+			len += sizeof(struct rmnet_map_dl_csum_trailer);
+
+		/* Charge the new packet with a proportional fraction of
+		 * the unused space in the original receive buffer.
+		 * XXX Charge a proportion of the *whole* receive buffer?
+		 */
+		if (!ipa_status_drop_packet(status)) {
+			u32 extra = unused * len / total_len;
+			void *data2 = data + sizeof(*status);
+			u32 len2 = le16_to_cpu(status->pkt_len);
+
+			/* Client receives only packet data (no status) */
+			ipa_endpoint_skb_copy(endpoint, data2, len2, extra);
+		}
+
+		/* Consume status and the full packet it describes */
+		data += len;
+		resid -= len;
+	}
+}
+
+/* Complete a TX transaction, command or from ipa_endpoint_skb_tx() */
+static void ipa_endpoint_tx_complete(struct ipa_endpoint *endpoint,
+				     struct gsi_trans *trans)
+{
+}
+
+/* Complete transaction initiated in ipa_endpoint_replenish_one() */
+static void ipa_endpoint_rx_complete(struct ipa_endpoint *endpoint,
+				     struct gsi_trans *trans)
+{
+	struct page *page;
+
+	ipa_endpoint_replenish(endpoint, true);
+
+	if (trans->cancelled)
+		return;
+
+	/* Parse or build a socket buffer using the actual received length */
+	page = trans->data;
+	if (endpoint->data->status_enable)
+		ipa_endpoint_status_parse(endpoint, page, trans->len);
+	else if (ipa_endpoint_skb_build(endpoint, page, trans->len))
+		trans->data = NULL;	/* Pages have been consumed */
+}
+
+void ipa_endpoint_trans_complete(struct ipa_endpoint *endpoint,
+				 struct gsi_trans *trans)
+{
+	if (endpoint->toward_ipa)
+		ipa_endpoint_tx_complete(endpoint, trans);
+	else
+		ipa_endpoint_rx_complete(endpoint, trans);
+}
+
+void ipa_endpoint_trans_release(struct ipa_endpoint *endpoint,
+				struct gsi_trans *trans)
+{
+	if (endpoint->toward_ipa) {
+		struct ipa *ipa = endpoint->ipa;
+
+		/* Nothing to do for command transactions */
+		if (endpoint != ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX]) {
+			struct sk_buff *skb = trans->data;
+
+			if (skb)
+				dev_kfree_skb_any(skb);
+		}
+	} else {
+		struct page *page = trans->data;
+
+		if (page)
+			__free_pages(page, IPA_RX_BUFFER_ORDER);
+	}
+}
+
+void ipa_endpoint_default_route_set(struct ipa *ipa, u32 endpoint_id)
+{
+	u32 val;
+
+	/* ROUTE_DIS is 0 */
+	val = u32_encode_bits(endpoint_id, ROUTE_DEF_PIPE_FMASK);
+	val |= ROUTE_DEF_HDR_TABLE_FMASK;
+	val |= u32_encode_bits(0, ROUTE_DEF_HDR_OFST_FMASK);
+	val |= u32_encode_bits(endpoint_id, ROUTE_FRAG_DEF_PIPE_FMASK);
+	val |= ROUTE_DEF_RETAIN_HDR_FMASK;
+
+	iowrite32(val, ipa->reg_virt + IPA_REG_ROUTE_OFFSET);
+}
+
+void ipa_endpoint_default_route_clear(struct ipa *ipa)
+{
+	ipa_endpoint_default_route_set(ipa, 0);
+}
+
+static bool ipa_endpoint_aggr_active(struct ipa_endpoint *endpoint)
+{
+	u32 mask = BIT(endpoint->endpoint_id);
+	struct ipa *ipa = endpoint->ipa;
+	u32 offset;
+	u32 val;
+
+	/* assert(mask & ipa->available); */
+	offset = ipa_reg_state_aggr_active_offset(ipa->version);
+	val = ioread32(ipa->reg_virt + offset);
+
+	return !!(val & mask);
+}
+
+static void ipa_endpoint_force_close(struct ipa_endpoint *endpoint)
+{
+	u32 mask = BIT(endpoint->endpoint_id);
+	struct ipa *ipa = endpoint->ipa;
+
+	/* assert(mask & ipa->available); */
+	iowrite32(mask, ipa->reg_virt + IPA_REG_AGGR_FORCE_CLOSE_OFFSET);
+}
+
+/**
+ * ipa_endpoint_reset_rx_aggr() - Reset RX endpoint with aggregation active
+ * @endpoint:	Endpoint to be reset
+ *
+ * If aggregation is active on an RX endpoint when a reset is performed
+ * on its underlying GSI channel, a special sequence of actions must be
+ * taken to ensure the IPA pipeline is properly cleared.
+ *
+ * @Return:	0 if successful, or a negative error code
+ */
+static int ipa_endpoint_reset_rx_aggr(struct ipa_endpoint *endpoint)
+{
+	struct device *dev = &endpoint->ipa->pdev->dev;
+	struct ipa *ipa = endpoint->ipa;
+	bool endpoint_suspended = false;
+	struct gsi *gsi = &ipa->gsi;
+	dma_addr_t addr;
+	bool db_enable;
+	u32 retries;
+	u32 len = 1;
+	void *virt;
+	int ret;
+
+	virt = kzalloc(len, GFP_KERNEL);
+	if (!virt)
+		return -ENOMEM;
+
+	addr = dma_map_single(dev, virt, len, DMA_FROM_DEVICE);
+	if (dma_mapping_error(dev, addr)) {
+		ret = -ENOMEM;
+		goto out_kfree;
+	}
+
+	/* Force close aggregation before issuing the reset */
+	ipa_endpoint_force_close(endpoint);
+
+	/* Reset and reconfigure the channel with the doorbell engine
+	 * disabled.  Then poll until we know aggregation is no longer
+	 * active.  We'll re-enable the doorbell (if appropriate) when
+	 * we reset again below.
+	 */
+	gsi_channel_reset(gsi, endpoint->channel_id, false);
+
+	/* Make sure the channel isn't suspended */
+	if (endpoint->ipa->version == IPA_VERSION_3_5_1)
+		if (!ipa_endpoint_init_ctrl(endpoint, false))
+			endpoint_suspended = true;
+
+	/* Start channel and do a 1 byte read */
+	ret = gsi_channel_start(gsi, endpoint->channel_id);
+	if (ret)
+		goto out_suspend_again;
+
+	ret = gsi_trans_read_byte(gsi, endpoint->channel_id, addr);
+	if (ret)
+		goto err_endpoint_stop;
+
+	/* Wait for aggregation to be closed on the channel */
+	retries = IPA_ENDPOINT_RESET_AGGR_RETRY_MAX;
+	do {
+		if (!ipa_endpoint_aggr_active(endpoint))
+			break;
+		msleep(1);
+	} while (retries--);
+
+	/* Check one last time */
+	if (ipa_endpoint_aggr_active(endpoint))
+		dev_err(dev, "endpoint %u still active during reset\n",
+			endpoint->endpoint_id);
+
+	gsi_trans_read_byte_done(gsi, endpoint->channel_id);
+
+	ret = ipa_endpoint_stop(endpoint);
+	if (ret)
+		goto out_suspend_again;
+
+	/* Finally, reset and reconfigure the channel again (re-enabling the
+	 * the doorbell engine if appropriate).  Sleep for 1 millisecond to
+	 * complete the channel reset sequence.  Finish by suspending the
+	 * channel again (if necessary).
+	 */
+	db_enable = ipa->version == IPA_VERSION_3_5_1;
+	gsi_channel_reset(gsi, endpoint->channel_id, db_enable);
+
+	msleep(1);
+
+	goto out_suspend_again;
+
+err_endpoint_stop:
+	ipa_endpoint_stop(endpoint);
+out_suspend_again:
+	if (endpoint_suspended)
+		(void)ipa_endpoint_init_ctrl(endpoint, true);
+	dma_unmap_single(dev, addr, len, DMA_FROM_DEVICE);
+out_kfree:
+	kfree(virt);
+
+	return ret;
+}
+
+static void ipa_endpoint_reset(struct ipa_endpoint *endpoint)
+{
+	u32 channel_id = endpoint->channel_id;
+	struct ipa *ipa = endpoint->ipa;
+	bool db_enable;
+	bool special;
+	int ret = 0;
+
+	/* On IPA v3.5.1, if an RX endpoint is reset while aggregation
+	 * is active, we need to handle things specially to recover.
+	 * All other cases just need to reset the underlying GSI channel.
+	 *
+	 * IPA v3.5.1 enables the doorbell engine.  Newer versions do not.
+	 */
+	db_enable = ipa->version == IPA_VERSION_3_5_1;
+	special = !endpoint->toward_ipa && endpoint->data->aggregation;
+	if (special && ipa_endpoint_aggr_active(endpoint))
+		ret = ipa_endpoint_reset_rx_aggr(endpoint);
+	else
+		gsi_channel_reset(&ipa->gsi, channel_id, db_enable);
+
+	if (ret)
+		dev_err(&ipa->pdev->dev,
+			"error %d resetting channel %u for endpoint %u\n",
+			ret, endpoint->channel_id, endpoint->endpoint_id);
+}
+
+static int ipa_endpoint_stop_rx_dma(struct ipa *ipa)
+{
+	u16 size = IPA_ENDPOINT_STOP_RX_SIZE;
+	struct gsi_trans *trans;
+	dma_addr_t addr;
+	int ret;
+
+	trans = ipa_cmd_trans_alloc(ipa, 1);
+	if (!trans) {
+		dev_err(&ipa->pdev->dev,
+			"no transaction for RX endpoint STOP workaround\n");
+		return -EBUSY;
+	}
+
+	/* Read into the highest part of the zero memory area */
+	addr = ipa->zero_addr + ipa->zero_size - size;
+
+	ipa_cmd_dma_task_32b_addr_add(trans, size, addr, false);
+
+	ret = gsi_trans_commit_wait_timeout(trans, ENDPOINT_STOP_DMA_TIMEOUT);
+	if (ret)
+		gsi_trans_free(trans);
+
+	return ret;
+}
+
+/**
+ * ipa_endpoint_stop() - Stops a GSI channel in IPA
+ * @client:	Client whose endpoint should be stopped
+ *
+ * This function implements the sequence to stop a GSI channel
+ * in IPA. This function returns when the channel is is STOP state.
+ *
+ * Return value: 0 on success, negative otherwise
+ */
+int ipa_endpoint_stop(struct ipa_endpoint *endpoint)
+{
+	u32 retries = IPA_ENDPOINT_STOP_RETRY_MAX;
+	int ret;
+
+	do {
+		struct ipa *ipa = endpoint->ipa;
+		struct gsi *gsi = &ipa->gsi;
+
+		ret = gsi_channel_stop(gsi, endpoint->channel_id);
+		if (ret != -EAGAIN)
+			break;
+
+		if (endpoint->toward_ipa)
+			continue;
+
+		/* For IPA v3.5.1, send a DMA read task and check again */
+		if (ipa->version == IPA_VERSION_3_5_1) {
+			ret = ipa_endpoint_stop_rx_dma(ipa);
+			if (ret)
+				break;
+		}
+
+		msleep(1);
+	} while (retries--);
+
+	return retries ? ret : -EIO;
+}
+
+static void ipa_endpoint_program(struct ipa_endpoint *endpoint)
+{
+	struct device *dev = &endpoint->ipa->pdev->dev;
+	int ret;
+
+	if (endpoint->toward_ipa) {
+		bool delay_mode = endpoint->data->tx.delay;
+
+		ret = ipa_endpoint_init_ctrl(endpoint, delay_mode);
+		/* Endpoint is expected to not be in delay mode */
+		if (!ret != delay_mode) {
+			dev_warn(dev,
+				"TX endpoint %u was %sin delay mode\n",
+				endpoint->endpoint_id,
+				delay_mode ? "already " : "");
+		}
+		ipa_endpoint_init_hdr_ext(endpoint);
+		ipa_endpoint_init_aggr(endpoint);
+		ipa_endpoint_init_deaggr(endpoint);
+		ipa_endpoint_init_seq(endpoint);
+	} else {
+		if (endpoint->ipa->version == IPA_VERSION_3_5_1) {
+			if (!ipa_endpoint_init_ctrl(endpoint, false))
+				dev_warn(dev,
+					"RX endpoint %u was suspended\n",
+					endpoint->endpoint_id);
+		}
+		ipa_endpoint_init_hdr_ext(endpoint);
+		ipa_endpoint_init_aggr(endpoint);
+	}
+	ipa_endpoint_init_cfg(endpoint);
+	ipa_endpoint_init_hdr(endpoint);
+	ipa_endpoint_init_hdr_metadata_mask(endpoint);
+	ipa_endpoint_init_mode(endpoint);
+	ipa_endpoint_status(endpoint);
+}
+
+int ipa_endpoint_enable_one(struct ipa_endpoint *endpoint)
+{
+	struct ipa *ipa = endpoint->ipa;
+	struct gsi *gsi = &ipa->gsi;
+	int ret;
+
+	ret = gsi_channel_start(gsi, endpoint->channel_id);
+	if (ret) {
+		dev_err(&ipa->pdev->dev,
+			"error %d starting %cX channel %u for endpoint %u\n",
+			endpoint->channel_id, endpoint->toward_ipa ? 'T' : 'R',
+			endpoint->endpoint_id);
+		return ret;
+	}
+
+	if (!endpoint->toward_ipa) {
+		ipa_interrupt_suspend_enable(ipa->interrupt,
+					     endpoint->endpoint_id);
+		ipa_endpoint_replenish_enable(endpoint);
+	}
+
+	ipa->enabled |= BIT(endpoint->endpoint_id);
+
+	return 0;
+}
+
+void ipa_endpoint_disable_one(struct ipa_endpoint *endpoint)
+{
+	u32 mask = BIT(endpoint->endpoint_id);
+	struct ipa *ipa = endpoint->ipa;
+	int ret;
+
+	if (!(endpoint->ipa->enabled & mask))
+		return;
+
+	endpoint->ipa->enabled ^= mask;
+
+	if (!endpoint->toward_ipa) {
+		ipa_endpoint_replenish_disable(endpoint);
+		ipa_interrupt_suspend_disable(ipa->interrupt,
+					      endpoint->endpoint_id);
+	}
+
+	/* Note that if stop fails, the channel's state is not well-defined */
+	ret = ipa_endpoint_stop(endpoint);
+	if (ret)
+		dev_err(&ipa->pdev->dev,
+			"error %d attempting to stop endpoint %u\n", ret,
+			endpoint->endpoint_id);
+}
+
+/**
+ * ipa_endpoint_suspend_aggr() - Emulate suspend interrupt
+ * @endpoint_id:	Endpoint on which to emulate a suspend
+ *
+ *  Emulate suspend IPA interrupt to unsuspend an endpoint suspended
+ *  with an open aggregation frame.  This is to work around a hardware
+ *  issue in IPA version 3.5.1 where the suspend interrupt will not be
+ *  generated when it should be.
+ */
+static void ipa_endpoint_suspend_aggr(struct ipa_endpoint *endpoint)
+{
+	struct ipa *ipa = endpoint->ipa;
+
+	/* assert(ipa->version == IPA_VERSION_3_5_1); */
+
+	if (!endpoint->data->aggregation)
+		return;
+
+	/* Nothing to do if the endpoint doesn't have aggregation open */
+	if (!ipa_endpoint_aggr_active(endpoint))
+		return;
+
+	/* Force close aggregation */
+	ipa_endpoint_force_close(endpoint);
+
+	ipa_interrupt_simulate_suspend(ipa->interrupt);
+}
+
+void ipa_endpoint_suspend_one(struct ipa_endpoint *endpoint)
+{
+	struct device *dev = &endpoint->ipa->pdev->dev;
+	struct gsi *gsi = &endpoint->ipa->gsi;
+	bool stop_channel;
+	int ret;
+
+	if (!(endpoint->ipa->enabled & BIT(endpoint->endpoint_id)))
+		return;
+
+	if (!endpoint->toward_ipa)
+		ipa_endpoint_replenish_disable(endpoint);
+
+	/* IPA v3.5.1 doesn't use channel stop for suspend */
+	stop_channel = endpoint->ipa->version != IPA_VERSION_3_5_1;
+	if (!endpoint->toward_ipa && !stop_channel) {
+		/* Due to a hardware bug, a client suspended with an open
+		 * aggregation frame will not generate a SUSPEND IPA
+		 * interrupt.  We work around this by force-closing the
+		 * aggregation frame, then simulating the arrival of such
+		 * an interrupt.
+		 */
+		WARN_ON(ipa_endpoint_init_ctrl(endpoint, true));
+		ipa_endpoint_suspend_aggr(endpoint);
+	}
+
+	ret = gsi_channel_suspend(gsi, endpoint->channel_id, stop_channel);
+	if (ret)
+		dev_err(dev, "error %d suspending channel %u\n", ret,
+			endpoint->channel_id);
+}
+
+void ipa_endpoint_resume_one(struct ipa_endpoint *endpoint)
+{
+	struct device *dev = &endpoint->ipa->pdev->dev;
+	struct gsi *gsi = &endpoint->ipa->gsi;
+	bool start_channel;
+	int ret;
+
+	if (!(endpoint->ipa->enabled & BIT(endpoint->endpoint_id)))
+		return;
+
+	/* IPA v3.5.1 doesn't use channel start for resume */
+	start_channel = endpoint->ipa->version != IPA_VERSION_3_5_1;
+	if (!endpoint->toward_ipa && !start_channel)
+		WARN_ON(ipa_endpoint_init_ctrl(endpoint, false));
+
+	ret = gsi_channel_resume(gsi, endpoint->channel_id, start_channel);
+	if (ret)
+		dev_err(dev, "error %d resuming channel %u\n", ret,
+			endpoint->channel_id);
+	else if (!endpoint->toward_ipa)
+		ipa_endpoint_replenish_enable(endpoint);
+}
+
+void ipa_endpoint_suspend(struct ipa *ipa)
+{
+	if (ipa->modem_netdev)
+		ipa_modem_suspend(ipa->modem_netdev);
+
+	ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_LAN_RX]);
+	ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX]);
+}
+
+void ipa_endpoint_resume(struct ipa *ipa)
+{
+	ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_COMMAND_TX]);
+	ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_LAN_RX]);
+
+	if (ipa->modem_netdev)
+		ipa_modem_resume(ipa->modem_netdev);
+}
+
+static void ipa_endpoint_setup_one(struct ipa_endpoint *endpoint)
+{
+	struct gsi *gsi = &endpoint->ipa->gsi;
+	u32 channel_id = endpoint->channel_id;
+
+	/* Only AP endpoints get set up */
+	if (endpoint->ee_id != GSI_EE_AP)
+		return;
+
+	endpoint->trans_tre_max = gsi_channel_trans_tre_max(gsi, channel_id);
+	if (!endpoint->toward_ipa) {
+		/* RX transactions require a single TRE, so the maximum
+		 * backlog is the same as the maximum outstanding TREs.
+		 */
+		endpoint->replenish_enabled = false;
+		atomic_set(&endpoint->replenish_saved,
+			   gsi_channel_tre_max(gsi, endpoint->channel_id));
+		atomic_set(&endpoint->replenish_backlog, 0);
+		INIT_DELAYED_WORK(&endpoint->replenish_work,
+				  ipa_endpoint_replenish_work);
+	}
+
+	ipa_endpoint_program(endpoint);
+
+	endpoint->ipa->set_up |= BIT(endpoint->endpoint_id);
+}
+
+static void ipa_endpoint_teardown_one(struct ipa_endpoint *endpoint)
+{
+	endpoint->ipa->set_up &= ~BIT(endpoint->endpoint_id);
+
+	if (!endpoint->toward_ipa)
+		cancel_delayed_work_sync(&endpoint->replenish_work);
+
+	ipa_endpoint_reset(endpoint);
+}
+
+void ipa_endpoint_setup(struct ipa *ipa)
+{
+	u32 initialized = ipa->initialized;
+
+	ipa->set_up = 0;
+	while (initialized) {
+		u32 endpoint_id = __ffs(initialized);
+
+		initialized ^= BIT(endpoint_id);
+
+		ipa_endpoint_setup_one(&ipa->endpoint[endpoint_id]);
+	}
+}
+
+void ipa_endpoint_teardown(struct ipa *ipa)
+{
+	u32 set_up = ipa->set_up;
+
+	while (set_up) {
+		u32 endpoint_id = __fls(set_up);
+
+		set_up ^= BIT(endpoint_id);
+
+		ipa_endpoint_teardown_one(&ipa->endpoint[endpoint_id]);
+	}
+	ipa->set_up = 0;
+}
+
+int ipa_endpoint_config(struct ipa *ipa)
+{
+	struct device *dev = &ipa->pdev->dev;
+	u32 initialized;
+	u32 rx_base;
+	u32 rx_mask;
+	u32 tx_mask;
+	int ret = 0;
+	u32 max;
+	u32 val;
+
+	/* Find out about the endpoints supplied by the hardware, and ensure
+	 * the highest one doesn't exceed the number we support.
+	 */
+	val = ioread32(ipa->reg_virt + IPA_REG_FLAVOR_0_OFFSET);
+
+	/* Our RX is an IPA producer */
+	rx_base = u32_get_bits(val, BAM_PROD_LOWEST_FMASK);
+	max = rx_base + u32_get_bits(val, BAM_MAX_PROD_PIPES_FMASK);
+	if (max > IPA_ENDPOINT_MAX) {
+		dev_err(dev, "too many endpoints (%u > %u)\n",
+			max, IPA_ENDPOINT_MAX);
+		return -EINVAL;
+	}
+	rx_mask = GENMASK(max - 1, rx_base);
+
+	/* Our TX is an IPA consumer */
+	max = u32_get_bits(val, BAM_MAX_CONS_PIPES_FMASK);
+	tx_mask = GENMASK(max - 1, 0);
+
+	ipa->available = rx_mask | tx_mask;
+
+	/* Check for initialized endpoints not supported by the hardware */
+	if (ipa->initialized & ~ipa->available) {
+		dev_err(dev, "unavailable endpoint id(s) 0x%08x\n",
+			ipa->initialized & ~ipa->available);
+		ret = -EINVAL;		/* Report other errors too */
+	}
+
+	initialized = ipa->initialized;
+	while (initialized) {
+		u32 endpoint_id = __ffs(initialized);
+		struct ipa_endpoint *endpoint;
+
+		initialized ^= BIT(endpoint_id);
+
+		/* Make sure it's pointing in the right direction */
+		endpoint = &ipa->endpoint[endpoint_id];
+		if ((endpoint_id < rx_base) != !!endpoint->toward_ipa) {
+			dev_err(dev, "endpoint id %u wrong direction\n",
+				endpoint_id);
+			ret = -EINVAL;
+		}
+	}
+
+	return ret;
+}
+
+void ipa_endpoint_deconfig(struct ipa *ipa)
+{
+	ipa->available = 0;	/* Nothing more to do */
+}
+
+static void ipa_endpoint_init_one(struct ipa *ipa, enum ipa_endpoint_name name,
+				  const struct ipa_gsi_endpoint_data *data)
+{
+	struct ipa_endpoint *endpoint;
+
+	endpoint = &ipa->endpoint[data->endpoint_id];
+
+	if (data->ee_id == GSI_EE_AP)
+		ipa->channel_map[data->channel_id] = endpoint;
+	ipa->name_map[name] = endpoint;
+
+	endpoint->ipa = ipa;
+	endpoint->ee_id = data->ee_id;
+	endpoint->seq_type = data->endpoint.seq_type;
+	endpoint->channel_id = data->channel_id;
+	endpoint->endpoint_id = data->endpoint_id;
+	endpoint->toward_ipa = data->toward_ipa;
+	endpoint->data = &data->endpoint.config;
+
+	ipa->initialized |= BIT(endpoint->endpoint_id);
+}
+
+void ipa_endpoint_exit_one(struct ipa_endpoint *endpoint)
+{
+	endpoint->ipa->initialized &= ~BIT(endpoint->endpoint_id);
+
+	memset(endpoint, 0, sizeof(*endpoint));
+}
+
+void ipa_endpoint_exit(struct ipa *ipa)
+{
+	u32 initialized = ipa->initialized;
+
+	while (initialized) {
+		u32 endpoint_id = __fls(initialized);
+
+		initialized ^= BIT(endpoint_id);
+
+		ipa_endpoint_exit_one(&ipa->endpoint[endpoint_id]);
+	}
+	memset(ipa->name_map, 0, sizeof(ipa->name_map));
+	memset(ipa->channel_map, 0, sizeof(ipa->channel_map));
+}
+
+/* Returns a bitmask of endpoints that support filtering, or 0 on error */
+u32 ipa_endpoint_init(struct ipa *ipa, u32 count,
+		      const struct ipa_gsi_endpoint_data *data)
+{
+	enum ipa_endpoint_name name;
+	u32 filter_map;
+
+	if (!ipa_endpoint_data_valid(ipa, count, data))
+		return 0;	/* Error */
+
+	ipa->initialized = 0;
+
+	filter_map = 0;
+	for (name = 0; name < count; name++, data++) {
+		if (ipa_gsi_endpoint_data_empty(data))
+			continue;	/* Skip over empty slots */
+
+		ipa_endpoint_init_one(ipa, name, data);
+
+		if (data->endpoint.filter_support)
+			filter_map |= BIT(data->endpoint_id);
+	}
+
+	if (!ipa_filter_map_valid(ipa, filter_map))
+		goto err_endpoint_exit;
+
+	return filter_map;	/* Non-zero bitmask */
+
+err_endpoint_exit:
+	ipa_endpoint_exit(ipa);
+
+	return 0;	/* Error */
+}
diff --git a/drivers/net/ipa/ipa_endpoint.h b/drivers/net/ipa/ipa_endpoint.h
new file mode 100644
index 000000000000..4b336a1f759d
--- /dev/null
+++ b/drivers/net/ipa/ipa_endpoint.h
@@ -0,0 +1,110 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2019-2020 Linaro Ltd.
+ */
+#ifndef _IPA_ENDPOINT_H_
+#define _IPA_ENDPOINT_H_
+
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <linux/if_ether.h>
+
+#include "gsi.h"
+#include "ipa_reg.h"
+
+struct net_device;
+struct sk_buff;
+
+struct ipa;
+struct ipa_gsi_endpoint_data;
+
+/* Non-zero granularity of counter used to implement aggregation timeout */
+#define IPA_AGGR_GRANULARITY		500	/* microseconds */
+
+#define IPA_MTU			ETH_DATA_LEN
+
+enum ipa_endpoint_name {
+	IPA_ENDPOINT_AP_MODEM_TX	= 0,
+	IPA_ENDPOINT_MODEM_LAN_TX,
+	IPA_ENDPOINT_MODEM_COMMAND_TX,
+	IPA_ENDPOINT_AP_COMMAND_TX,
+	IPA_ENDPOINT_MODEM_AP_TX,
+	IPA_ENDPOINT_AP_LAN_RX,
+	IPA_ENDPOINT_AP_MODEM_RX,
+	IPA_ENDPOINT_MODEM_AP_RX,
+	IPA_ENDPOINT_MODEM_LAN_RX,
+	IPA_ENDPOINT_COUNT,	/* Number of names (not an index) */
+};
+
+#define IPA_ENDPOINT_MAX		32	/* Max supported by driver */
+
+/**
+ * struct ipa_endpoint - IPA endpoint information
+ * @client:	Client associated with the endpoint
+ * @channel_id:	EP's GSI channel
+ * @evt_ring_id: EP's GSI channel event ring
+ */
+struct ipa_endpoint {
+	struct ipa *ipa;
+	enum ipa_seq_type seq_type;
+	enum gsi_ee_id ee_id;
+	u32 channel_id;
+	u32 endpoint_id;
+	bool toward_ipa;
+	const struct ipa_endpoint_config_data *data;
+
+	u32 trans_tre_max;	/* maximum descriptors per transaction */
+	u32 evt_ring_id;
+
+	/* Net device this endpoint is associated with, if any */
+	struct net_device *netdev;
+
+	/* Receive buffer replenishing for RX endpoints */
+	bool replenish_enabled;
+	u32 replenish_ready;
+	atomic_t replenish_saved;
+	atomic_t replenish_backlog;
+	struct delayed_work replenish_work;		/* global wq */
+};
+
+void ipa_endpoint_modem_hol_block_clear_all(struct ipa *ipa);
+
+void ipa_endpoint_modem_pause_all(struct ipa *ipa, bool enable);
+
+int ipa_endpoint_modem_exception_reset_all(struct ipa *ipa);
+
+int ipa_endpoint_skb_tx(struct ipa_endpoint *endpoint, struct sk_buff *skb);
+
+int ipa_endpoint_stop(struct ipa_endpoint *endpoint);
+
+void ipa_endpoint_exit_one(struct ipa_endpoint *endpoint);
+
+int ipa_endpoint_enable_one(struct ipa_endpoint *endpoint);
+void ipa_endpoint_disable_one(struct ipa_endpoint *endpoint);
+
+void ipa_endpoint_suspend_one(struct ipa_endpoint *endpoint);
+void ipa_endpoint_resume_one(struct ipa_endpoint *endpoint);
+
+void ipa_endpoint_suspend(struct ipa *ipa);
+void ipa_endpoint_resume(struct ipa *ipa);
+
+void ipa_endpoint_setup(struct ipa *ipa);
+void ipa_endpoint_teardown(struct ipa *ipa);
+
+int ipa_endpoint_config(struct ipa *ipa);
+void ipa_endpoint_deconfig(struct ipa *ipa);
+
+void ipa_endpoint_default_route_set(struct ipa *ipa, u32 endpoint_id);
+void ipa_endpoint_default_route_clear(struct ipa *ipa);
+
+u32 ipa_endpoint_init(struct ipa *ipa, u32 count,
+		      const struct ipa_gsi_endpoint_data *data);
+void ipa_endpoint_exit(struct ipa *ipa);
+
+void ipa_endpoint_trans_complete(struct ipa_endpoint *ipa,
+				 struct gsi_trans *trans);
+void ipa_endpoint_trans_release(struct ipa_endpoint *ipa,
+				struct gsi_trans *trans);
+
+#endif /* _IPA_ENDPOINT_H_ */