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From: Alex Elder <elder@linaro.org>
To: davem@davemloft.net, arnd@arndb.de, bjorn.andersson@linaro.org,
	ilias.apalodimas@linaro.org
Cc: netdev@vger.kernel.org, devicetree@vger.kernel.org,
	linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, syadagir@codeaurora.org,
	mjavid@codeaurora.org, robh+dt@kernel.org, mark.rutland@arm.com
Subject: [RFC PATCH 10/12] soc: qcom: ipa: data path
Date: Tue,  6 Nov 2018 18:32:48 -0600
Message-ID: <20181107003250.5832-11-elder@linaro.org> (raw)
In-Reply-To: <20181107003250.5832-1-elder@linaro.org>

This patch contains "ipa_dp.c", which includes the bulk of the data
path code.  There is an overview in the code of how things operate,
but there are already plans to rework this portion of the driver.

In particular:
  - Interrupt handling will be replaced with a threaded interrupt
    handler.  Currently handling occurs in a combination of
    interrupt and workqueue context, and this requires locking
    and atomic operations for proper synchronization.
  - Currently, only receive endpoints use NAPI.  Transmit
    completion interrupts are disabled, and are handled in batches
    by periodically scheduling an interrupting no-op request.
    The plan is to arrange for transmit requests to generate
    interrupts, and their completion will be processed with other
    completions in the NAPI poll function.  This will also allow
    accurate feedback about packet sojourn time to be provided to
    queue limiting mechanisms.
  - Not all receive endpoints use NAPI.  The plan is for *all*
    endpoints to use NAPI.  And because all endpoints share a
    common GSI interrupt, a single NAPI structure will used to
    managing the processing for all completions on all endpoints.
  - Receive buffers are posted to the hardware by a workqueue
    function.  Instead, the plan is to have this done by the
    NAPI poll routine.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_dp.c | 1994 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 1994 insertions(+)
 create mode 100644 drivers/net/ipa/ipa_dp.c

diff --git a/drivers/net/ipa/ipa_dp.c b/drivers/net/ipa/ipa_dp.c
new file mode 100644
index 000000000000..c16ac74765b8
--- /dev/null
+++ b/drivers/net/ipa/ipa_dp.c
@@ -0,0 +1,1994 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2018 Linaro Ltd.
+ */
+
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+
+#include "ipa_i.h"	/* ipa_err() */
+#include "ipahal.h"
+#include "ipa_dma.h"
+
+/**
+ * DOC:  The IPA Data Path
+ *
+ * The IPA is used to transmit data between execution environments.
+ * The data path code uses functions and structures supplied by the
+ * GSI to interact with the IPA hardware.  A packet to be transmitted
+ * or received is held in a socket buffer.  Each has a "wrapper"
+ * structure associated with it.  A GSI transfer request refers to
+ * the packet wrapper, and when queued to the hardware the packet
+ * wrapper is added to a list of outstanding requests for an endpoint
+ * (maintained in the head_desc_list in the endpoint's system context).
+ * When the GSI transfer completes, a callback function is provided
+ * the packet wrapper pointer, allowing it to be released after the
+ * received socket buffer has been passed up the stack, or a buffer
+ * whose data has been transmitted has been freed.
+ *
+ * Producer (PROD) endpoints are used to send data from the AP toward
+ * the IPA.  The common function for sending data on producer endpoints
+ * is ipa_send().  It takes a system context and an array of IPA
+ * descriptors as arguments.  Each descriptor is given a TX packet
+ * wrapper, and its content is translated into an equivalent GSI
+ * transfer element  structure after its memory address is mapped for
+ * DMA.  The GSI transfer element array is finally passed to the GSI
+ * layer using gsi_channel_queue().
+ *
+ * The code provides a "no_intr" feature, allowing endpoints to have
+ * their transmit completions not produce an interrupt.  (This
+ * behavior is used only for the modem producer.)  In this case, a
+ * no-op request is generated every 200 milliseconds while transmit
+ * requests are outstanding.  The no-op will generate an interrupt
+ * when it's complete, and its completion implies the completion of
+ * all transmit requests issued before it.  The GSI will call
+ * ipa_gsi_irq_tx_notify_cb() in response to interrupts on a producer
+ * endpoint.
+ *
+ * Receive buffers are passed to consumer (CONS) channels to be
+ * available to hold incoming data.  Arriving data is placed
+ * in these buffers, leading to events being generated on the event
+ * ring assciated with a channel.  When an interrupt occurs on a
+ * consumer endpoint, the GSI layer calls ipa_gsi_irq_rx_notify_cb().
+ * This causes the endpoint to switch to polling mode.  The
+ * completion of a receive also leads to ipa_replenish_rx_cache()
+ * being called, to replace the consumed buffer.
+ *
+ * Consumer enpoints optionally use NAPI (only the modem consumer,
+ * WWAN_CONS, does currently).  An atomic variable records whether
+ * the endpoint is in polling mode or not.  This is needed because
+ * switching to polling mode is currently done in a workqueue.  Once
+ * NAPI polling completes, and endpoint switches back to interrupt
+ * mode.
+ */
+
+/**
+ * struct ipa_tx_pkt_wrapper - IPA transmit packet wrapper
+ * @type:	type of descriptor
+ * @sys:	Corresponding IPA sys context
+ * @mem:	Memory buffer used by this packet
+ * @callback:	IPA client provided callback
+ * @user1:	Cookie1 for above callback
+ * @user2:	Cookie2 for above callback
+ * @link:	Links for the endpoint's sys->head_desc_list
+ * @cnt:	Number of descriptors in request
+ * @done_work:	Work structure used when complete
+ */
+struct ipa_tx_pkt_wrapper {
+	enum ipa_desc_type type;
+	struct ipa_sys_context *sys;
+	struct ipa_dma_mem mem;
+	void (*callback)(void *user1, int user2);
+	void *user1;
+	int user2;
+	struct list_head link;
+	u32 cnt;
+	struct work_struct done_work;
+};
+
+/** struct ipa_rx_pkt_wrapper - IPA Rx packet wrapper
+ * @link:	Links for the endpoint's sys->head_desc_list
+ * @skb:	Socket buffer containing the received packet
+ * @len:	How many bytes are copied into skb's buffer
+ */
+struct ipa_rx_pkt_wrapper {
+	struct list_head link;
+	struct sk_buff *skb;
+	dma_addr_t dma_addr;
+};
+
+/** struct ipa_sys_context - IPA GPI endpoint context
+ * @len:	The number of entries in @head_desc_list
+ * @tx:		Details related to AP->IPA endpoints
+ * @rx:		Details related to IPA->AP endpoints
+ * @ep:		Associated endpoint
+ * @head_desc_list: List of packets
+ * @spinlock:	Lock protecting the descriptor list
+ * @workqueue:	Workqueue used for this endpoint
+ */
+struct ipa_sys_context {
+	u32 len;
+	union {
+		struct {	/* Consumer endpoints only */
+			u32 len_pending_xfer;
+			atomic_t curr_polling_state;
+			struct delayed_work switch_to_intr_work; /* sys->wq */
+			void (*pyld_hdlr)(struct sk_buff *,
+					  struct ipa_sys_context *);
+			u32 buff_sz;
+			u32 pool_sz;
+			struct sk_buff *prev_skb;
+			unsigned int len_rem;
+			unsigned int len_pad;		/* APPS_LAN only */
+			unsigned int len_partial;	/* APPS_LAN only */
+			bool drop_packet;		/* APPS_LAN only */
+
+			struct work_struct work; /* sys->wq */
+			struct delayed_work replenish_work; /* sys->wq */
+		} rx;
+		struct {	/* Producer endpoints only */
+			/* no_intr/nop is APPS_WAN_PROD only */
+			bool no_intr;
+			atomic_t nop_pending;
+			struct hrtimer nop_timer;
+			struct work_struct nop_work; /* sys->wq */
+		} tx;
+	};
+
+	/* ordering is important - mutable fields go above */
+	struct ipa_ep_context *ep;
+	struct list_head head_desc_list; /* contains len entries */
+	spinlock_t spinlock;		/* protects head_desc list */
+	struct workqueue_struct *wq;
+	/* ordering is important - other immutable fields go below */
+};
+
+/**
+ * struct ipa_dp - IPA data path information
+ * @tx_pkt_wrapper_cache:	Tx packets cache
+ * @rx_pkt_wrapper_cache:	Rx packets cache
+ */
+struct ipa_dp {
+	struct kmem_cache *tx_pkt_wrapper_cache;
+	struct kmem_cache *rx_pkt_wrapper_cache;
+};
+
+/**
+ * struct ipa_tag_completion - Reference counted completion object
+ * @comp:	Completion when last reference is dropped
+ * @cnt:	Reference count
+ */
+struct ipa_tag_completion {
+	struct completion comp;
+	atomic_t cnt;
+};
+
+#define CHANNEL_RESET_AGGR_RETRY_COUNT	3
+#define CHANNEL_RESET_DELAY		1	/* milliseconds */
+
+#define IPA_QMAP_HEADER_LENGTH		4
+
+#define IPA_WAN_AGGR_PKT_CNT		5
+#define POLLING_INACTIVITY_RX		40
+#define POLLING_MIN_SLEEP_RX		1010	/* microseconds */
+#define POLLING_MAX_SLEEP_RX		1050	/* microseconds */
+
+#define IPA_RX_BUFFER_ORDER	1	/* Default RX buffer is 2^1 pages */
+#define IPA_RX_BUFFER_SIZE	(1 << (IPA_RX_BUFFER_ORDER + PAGE_SHIFT))
+
+/* The amount of RX buffer space consumed by standard skb overhead */
+#define IPA_RX_BUFFER_RESERVED \
+	(IPA_RX_BUFFER_SIZE - SKB_MAX_ORDER(NET_SKB_PAD, IPA_RX_BUFFER_ORDER))
+
+/* RX buffer space remaining after standard overhead is consumed */
+#define IPA_RX_BUFFER_AVAILABLE(X)	((X) - IPA_RX_BUFFER_RESERVED)
+
+#define IPA_RX_BUFF_CLIENT_HEADROOM	256
+
+#define IPA_SIZE_DL_CSUM_META_TRAILER	8
+
+#define IPA_REPL_XFER_THRESH		10
+
+/* How long before sending an interrupting no-op to handle TX completions */
+#define IPA_TX_NOP_DELAY_NS		(2 * 1000 * 1000)	/* 2 msec */
+
+static void ipa_rx_switch_to_intr_mode(struct ipa_sys_context *sys);
+
+static void ipa_replenish_rx_cache(struct ipa_sys_context *sys);
+static void ipa_replenish_rx_work_func(struct work_struct *work);
+static void ipa_wq_handle_rx(struct work_struct *work);
+static void ipa_rx_common(struct ipa_sys_context *sys, u32 size);
+static void ipa_cleanup_rx(struct ipa_sys_context *sys);
+static int ipa_poll_gsi_pkt(struct ipa_sys_context *sys);
+
+static void ipa_tx_complete(struct ipa_tx_pkt_wrapper *tx_pkt)
+{
+	struct device *dev = ipa_ctx->dev;
+
+	/* If DMA memory was mapped, unmap it */
+	if (tx_pkt->mem.virt) {
+		if (tx_pkt->type == IPA_DATA_DESC_SKB_PAGED)
+			dma_unmap_page(dev, tx_pkt->mem.phys,
+				       tx_pkt->mem.size, DMA_TO_DEVICE);
+		else
+			dma_unmap_single(dev, tx_pkt->mem.phys,
+					 tx_pkt->mem.size, DMA_TO_DEVICE);
+	}
+
+	if (tx_pkt->callback)
+		tx_pkt->callback(tx_pkt->user1, tx_pkt->user2);
+
+	kmem_cache_free(ipa_ctx->dp->tx_pkt_wrapper_cache, tx_pkt);
+}
+
+static void
+ipa_wq_write_done_common(struct ipa_sys_context *sys,
+			 struct ipa_tx_pkt_wrapper *tx_pkt)
+{
+	struct ipa_tx_pkt_wrapper *next_pkt;
+	int cnt;
+	int i;
+
+	cnt = tx_pkt->cnt;
+	for (i = 0; i < cnt; i++) {
+		ipa_assert(!list_empty(&sys->head_desc_list));
+
+		spin_lock_bh(&sys->spinlock);
+
+		next_pkt = list_next_entry(tx_pkt, link);
+		list_del(&tx_pkt->link);
+		sys->len--;
+
+		spin_unlock_bh(&sys->spinlock);
+
+		ipa_tx_complete(tx_pkt);
+
+		tx_pkt = next_pkt;
+	}
+}
+
+/**
+ * ipa_wq_write_done() - Work function executed when TX completes
+ * * @done_work:	work_struct used by the work queue
+ */
+static void ipa_wq_write_done(struct work_struct *done_work)
+{
+	struct ipa_tx_pkt_wrapper *this_pkt;
+	struct ipa_tx_pkt_wrapper *tx_pkt;
+	struct ipa_sys_context *sys;
+
+	tx_pkt = container_of(done_work, struct ipa_tx_pkt_wrapper, done_work);
+	sys = tx_pkt->sys;
+	spin_lock_bh(&sys->spinlock);
+	this_pkt = list_first_entry(&sys->head_desc_list,
+				    struct ipa_tx_pkt_wrapper, link);
+	while (tx_pkt != this_pkt) {
+		spin_unlock_bh(&sys->spinlock);
+		ipa_wq_write_done_common(sys, this_pkt);
+		spin_lock_bh(&sys->spinlock);
+		this_pkt = list_first_entry(&sys->head_desc_list,
+					    struct ipa_tx_pkt_wrapper, link);
+	}
+	spin_unlock_bh(&sys->spinlock);
+	ipa_wq_write_done_common(sys, tx_pkt);
+}
+
+/**
+ * ipa_rx_poll() - Poll the rx packets from IPA hardware
+ * @ep_id:	Endpoint to poll
+ * @weight:	NAPI poll weight
+ *
+ * Return:	The number of received packets.
+ */
+int ipa_rx_poll(u32 ep_id, int weight)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+	static int total_cnt;
+	int cnt = 0;
+
+	while (cnt < weight && ipa_ep_polling(ep)) {
+		int ret;
+
+		ret = ipa_poll_gsi_pkt(ep->sys);
+		if (ret < 0)
+			break;
+
+		ipa_rx_common(ep->sys, (u32)ret);
+		cnt += IPA_WAN_AGGR_PKT_CNT;
+		total_cnt++;
+
+		/* Force switch back to interrupt mode if no more packets */
+		if (!ep->sys->len || total_cnt >= ep->sys->rx.pool_sz) {
+			total_cnt = 0;
+			cnt--;
+			break;
+		}
+	}
+
+	if (cnt < weight) {
+		ep->client_notify(ep->priv, IPA_CLIENT_COMP_NAPI, 0);
+		ipa_rx_switch_to_intr_mode(ep->sys);
+
+		/* Matching enable is in ipa_gsi_irq_rx_notify_cb() */
+		ipa_client_remove();
+	}
+
+	return cnt;
+}
+
+/**
+ * ipa_send_nop() - Send an interrupting no-op request to a producer endpoint.
+ * @sys:	System context for the endpoint
+ *
+ * Normally an interrupt is generated upon completion of every transfer
+ * performed by an endpoint, but a producer endpoint can be configured
+ * to avoid getting these interrupts.  Instead, once a transfer has been
+ * initiated, a no-op is scheduled to be sent after a short delay.  This
+ * no-op request will interrupt when it is complete, and in handling that
+ * interrupt, previously-completed transfers will be handled as well.  If
+ * a no-op is already scheduled, another is not initiated (there's only
+ * one pending at a time).
+ */
+static bool ipa_send_nop(struct ipa_sys_context *sys)
+{
+	struct gsi_xfer_elem nop_xfer = { };
+	struct ipa_tx_pkt_wrapper *nop_pkt;
+	u32 channel_id;
+
+	nop_pkt = kmem_cache_zalloc(ipa_ctx->dp->tx_pkt_wrapper_cache,
+				    GFP_KERNEL);
+	if (!nop_pkt)
+		return false;
+
+	nop_pkt->type = IPA_DATA_DESC;
+	/* No-op packet uses no memory for data */
+	INIT_WORK(&nop_pkt->done_work, ipa_wq_write_done);
+	nop_pkt->sys = sys;
+	nop_pkt->cnt = 1;
+
+	nop_xfer.type = GSI_XFER_ELEM_NOP;
+	nop_xfer.flags = GSI_XFER_FLAG_EOT;
+	nop_xfer.user_data = nop_pkt;
+
+	spin_lock_bh(&sys->spinlock);
+	list_add_tail(&nop_pkt->link, &sys->head_desc_list);
+	spin_unlock_bh(&sys->spinlock);
+
+	channel_id = sys->ep->channel_id;
+	if (!gsi_channel_queue(ipa_ctx->gsi, channel_id, 1, &nop_xfer, true))
+		return true;	/* Success */
+
+	spin_lock_bh(&sys->spinlock);
+	list_del(&nop_pkt->link);
+	spin_unlock_bh(&sys->spinlock);
+
+	kmem_cache_free(ipa_ctx->dp->tx_pkt_wrapper_cache, nop_pkt);
+
+	return false;
+}
+
+/**
+ * ipa_send_nop_work() - Work function for sending a no-op request
+ * nop_work:	Work structure for the request
+ *
+ * Try to send the no-op request.  If it fails, arrange to try again.
+ */
+static void ipa_send_nop_work(struct work_struct *nop_work)
+{
+	struct ipa_sys_context *sys;
+
+	sys = container_of(nop_work, struct ipa_sys_context, tx.nop_work);
+
+	/* If sending a no-op request fails, schedule another try */
+	if (!ipa_send_nop(sys))
+		queue_work(sys->wq, nop_work);
+}
+
+/**
+ * ipa_nop_timer_expiry() - Timer function to schedule a no-op request
+ * @timer:	High-resolution timer structure
+ *
+ * The delay before sending the no-op request is implemented by a
+ * high resolution timer, which will call this in interrupt context.
+ * Arrange to send the no-op in workqueue context when it expires.
+ */
+static enum hrtimer_restart ipa_nop_timer_expiry(struct hrtimer *timer)
+{
+	struct ipa_sys_context *sys;
+
+	sys = container_of(timer, struct ipa_sys_context, tx.nop_timer);
+	atomic_set(&sys->tx.nop_pending, 0);
+	queue_work(sys->wq, &sys->tx.nop_work);
+
+	return HRTIMER_NORESTART;
+}
+
+static void ipa_nop_timer_schedule(struct ipa_sys_context *sys)
+{
+	ktime_t time;
+
+	if (atomic_xchg(&sys->tx.nop_pending, 1))
+		return;
+
+	time = ktime_set(0, IPA_TX_NOP_DELAY_NS);
+	hrtimer_start(&sys->tx.nop_timer, time, HRTIMER_MODE_REL);
+}
+
+/**
+ * ipa_no_intr_init() - Configure endpoint point for no-op requests
+ * @prod_ep_id:	Endpoint that will use interrupting no-ops
+ *
+ * For some producer endpoints we don't interrupt on completions.
+ * Instead we schedule an interrupting NOP command to be issued on
+ * the endpoint after a short delay (if one is not already scheduled).
+ * When the NOP completes it signals all preceding transfers have
+ * completed also.
+ */
+void ipa_no_intr_init(u32 prod_ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[prod_ep_id];
+
+	INIT_WORK(&ep->sys->tx.nop_work, ipa_send_nop_work);
+	atomic_set(&ep->sys->tx.nop_pending, 0);
+	hrtimer_init(&ep->sys->tx.nop_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	ep->sys->tx.nop_timer.function = ipa_nop_timer_expiry;
+	ep->sys->tx.no_intr = true;
+}
+
+/**
+ * ipa_send() - Send descriptors to hardware as a single transaction
+ * @sys:	System context for endpoint
+ * @num_desc:	Number of descriptors
+ * @desc:	Transfer descriptors to send
+ *
+ * Return:	0 iff successful, or a negative error code.
+ */
+static int
+ipa_send(struct ipa_sys_context *sys, u32 num_desc, struct ipa_desc *desc)
+{
+	struct ipa_tx_pkt_wrapper *tx_pkt;
+	struct ipa_tx_pkt_wrapper *first;
+	struct ipa_tx_pkt_wrapper *next;
+	struct gsi_xfer_elem *xfer_elem;
+	LIST_HEAD(pkt_list);
+	int ret;
+	int i;
+
+	ipa_assert(num_desc);
+	ipa_assert(num_desc <= ipa_client_tlv_count(sys->ep->client));
+
+	xfer_elem = kcalloc(num_desc, sizeof(*xfer_elem), GFP_ATOMIC);
+	if (!xfer_elem)
+		return -ENOMEM;
+
+	/* Within loop, all errors are allocation or DMA mapping */
+	ret = -ENOMEM;
+	first = NULL;
+	for (i = 0; i < num_desc; i++) {
+		dma_addr_t phys;
+
+		tx_pkt = kmem_cache_zalloc(ipa_ctx->dp->tx_pkt_wrapper_cache,
+					   GFP_ATOMIC);
+		if (!tx_pkt)
+			goto err_unwind;
+
+		if (!first)
+			first = tx_pkt;
+
+		if (desc[i].type == IPA_DATA_DESC_SKB_PAGED)
+			phys = skb_frag_dma_map(ipa_ctx->dev, desc[i].payload,
+						0, desc[i].len_opcode,
+						DMA_TO_DEVICE);
+		else
+			phys = dma_map_single(ipa_ctx->dev, desc[i].payload,
+					      desc[i].len_opcode,
+					      DMA_TO_DEVICE);
+		if (dma_mapping_error(ipa_ctx->dev, phys)) {
+			ipa_err("dma mapping error on descriptor\n");
+			kmem_cache_free(ipa_ctx->dp->tx_pkt_wrapper_cache,
+					tx_pkt);
+			goto err_unwind;
+		}
+
+		tx_pkt->type = desc[i].type;
+		tx_pkt->sys = sys;
+		tx_pkt->mem.virt = desc[i].payload;
+		tx_pkt->mem.phys = phys;
+		tx_pkt->mem.size = desc[i].len_opcode;
+		tx_pkt->callback = desc[i].callback;
+		tx_pkt->user1 = desc[i].user1;
+		tx_pkt->user2 = desc[i].user2;
+		list_add_tail(&tx_pkt->link, &pkt_list);
+
+		xfer_elem[i].addr = tx_pkt->mem.phys;
+		if (desc[i].type == IPA_IMM_CMD_DESC)
+			xfer_elem[i].type = GSI_XFER_ELEM_IMME_CMD;
+		else
+			xfer_elem[i].type = GSI_XFER_ELEM_DATA;
+		xfer_elem[i].len_opcode = desc[i].len_opcode;
+		if (i < num_desc - 1)
+			xfer_elem[i].flags = GSI_XFER_FLAG_CHAIN;
+	}
+
+	/* Fill in extra fields in the first TX packet */
+	first->cnt = num_desc;
+	INIT_WORK(&first->done_work, ipa_wq_write_done);
+
+	/* Fill in extra fields in the last transfer element */
+	if (!sys->tx.no_intr) {
+		xfer_elem[num_desc - 1].flags = GSI_XFER_FLAG_EOT;
+		xfer_elem[num_desc - 1].flags |= GSI_XFER_FLAG_BEI;
+	}
+	xfer_elem[num_desc - 1].user_data = first;
+
+	spin_lock_bh(&sys->spinlock);
+
+	list_splice_tail_init(&pkt_list, &sys->head_desc_list);
+	ret = gsi_channel_queue(ipa_ctx->gsi, sys->ep->channel_id, num_desc,
+				xfer_elem, true);
+	if (ret)
+		list_cut_end(&pkt_list, &sys->head_desc_list, &first->link);
+
+	spin_unlock_bh(&sys->spinlock);
+
+	kfree(xfer_elem);
+
+	if (!ret) {
+		if (sys->tx.no_intr)
+			ipa_nop_timer_schedule(sys);
+		return 0;
+	}
+err_unwind:
+	list_for_each_entry_safe(tx_pkt, next, &pkt_list, link) {
+		list_del(&tx_pkt->link);
+		tx_pkt->callback = NULL; /* Avoid doing the callback */
+		ipa_tx_complete(tx_pkt);
+	}
+
+	return ret;
+}
+
+/**
+ * ipa_send_cmd_timeout_complete() - Command completion callback
+ * @user1:	Opaque value carried by the command
+ * @ignored:	Second opaque value (ignored)
+ *
+ * Schedule a completion to signal that a command is done.  Free the
+ * tag_completion structure if its reference count reaches zero.
+ */
+static void ipa_send_cmd_timeout_complete(void *user1, int ignored)
+{
+	struct ipa_tag_completion *comp = user1;
+
+	complete(&comp->comp);
+	if (!atomic_dec_return(&comp->cnt))
+		kfree(comp);
+}
+
+/**
+ * ipa_send_cmd_timeout() - Send an immediate command with timeout
+ * @desc:	descriptor structure
+ * @timeout:	milliseconds to wait (or 0 to wait indefinitely)
+ *
+ * Send an immediate command, and wait for it to complete.  If
+ * timeout is non-zero it indicates the number of milliseconds to
+ * wait to receive the acknowledgment from the hardware before
+ * timing out.  If 0 is supplied, wait will not time out.
+ *
+ * Return:	0 if successful, or a negative error code
+ */
+int ipa_send_cmd_timeout(struct ipa_desc *desc, u32 timeout)
+{
+	struct ipa_tag_completion *comp;
+	unsigned long timeout_jiffies;
+	struct ipa_ep_context *ep;
+	int ret;
+
+	comp = kzalloc(sizeof(*comp), GFP_KERNEL);
+	if (!comp)
+		return -ENOMEM;
+
+	/* The reference count is decremented both here and in ack
+	 * callback.  Whichever reaches 0 frees the structure.
+	 */
+	atomic_set(&comp->cnt, 2);
+	init_completion(&comp->comp);
+
+	/* Fill in the callback info (the sole descriptor is the last) */
+	desc->callback = ipa_send_cmd_timeout_complete;
+	desc->user1 = comp;
+
+	ep = &ipa_ctx->ep[ipa_client_ep_id(IPA_CLIENT_APPS_CMD_PROD)];
+	ret = ipa_send(ep->sys, 1, desc);
+	if (ret) {
+		/* Callback won't run; drop reference on its behalf */
+		atomic_dec(&comp->cnt);
+		goto out;
+	}
+
+	timeout_jiffies = msecs_to_jiffies(timeout);
+	if (!timeout_jiffies) {
+		wait_for_completion(&comp->comp);
+	} else if (!wait_for_completion_timeout(&comp->comp, timeout_jiffies)) {
+		ret = -ETIMEDOUT;
+		ipa_err("command timed out\n");
+	}
+out:
+	if (!atomic_dec_return(&comp->cnt))
+		kfree(comp);
+
+	return ret;
+}
+
+/**
+ * ipa_handle_rx_core() - Core packet reception handling
+ * @sys:	System context for endpoint receiving packets
+ *
+ * Return:	The number of packets processed, or a negative error code
+ */
+static int ipa_handle_rx_core(struct ipa_sys_context *sys)
+{
+	int cnt;
+
+	/* Stop if the endpoint leaves polling state */
+	cnt = 0;
+	while (ipa_ep_polling(sys->ep)) {
+		int ret = ipa_poll_gsi_pkt(sys);
+
+		if (ret < 0)
+			break;
+
+		ipa_rx_common(sys, (u32)ret);
+
+		cnt++;
+	}
+
+	return cnt;
+}
+
+/**
+ * ipa_rx_switch_to_intr_mode() - Switch from polling to interrupt mode
+ * @sys:	System context for endpoint switching mode
+ */
+static void ipa_rx_switch_to_intr_mode(struct ipa_sys_context *sys)
+{
+	if (!atomic_xchg(&sys->rx.curr_polling_state, 0)) {
+		ipa_err("already in intr mode\n");
+		queue_delayed_work(sys->wq, &sys->rx.switch_to_intr_work,
+				   msecs_to_jiffies(1));
+		return;
+	}
+	ipa_dec_release_wakelock();
+	gsi_channel_intr_enable(ipa_ctx->gsi, sys->ep->channel_id);
+}
+
+void ipa_rx_switch_to_poll_mode(struct ipa_sys_context *sys)
+{
+	if (atomic_xchg(&sys->rx.curr_polling_state, 1))
+		return;
+	gsi_channel_intr_disable(ipa_ctx->gsi, sys->ep->channel_id);
+	ipa_inc_acquire_wakelock();
+	queue_work(sys->wq, &sys->rx.work);
+}
+
+/**
+ * ipa_handle_rx() - Handle packet reception.
+ * @sys:	System context for endpoint receiving packets
+ */
+static void ipa_handle_rx(struct ipa_sys_context *sys)
+{
+	int inactive_cycles = 0;
+	int cnt;
+
+	ipa_client_add();
+	do {
+		cnt = ipa_handle_rx_core(sys);
+		if (cnt == 0)
+			inactive_cycles++;
+		else
+			inactive_cycles = 0;
+
+		usleep_range(POLLING_MIN_SLEEP_RX, POLLING_MAX_SLEEP_RX);
+
+		/* if endpoint is out of buffers there is no point polling for
+		 * completed descs; release the worker so delayed work can
+		 * run in a timely manner
+		 */
+		if (sys->len - sys->rx.len_pending_xfer == 0)
+			break;
+
+	} while (inactive_cycles <= POLLING_INACTIVITY_RX);
+
+	ipa_rx_switch_to_intr_mode(sys);
+	ipa_client_remove();
+}
+
+static void ipa_switch_to_intr_rx_work_func(struct work_struct *work)
+{
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct ipa_sys_context *sys;
+
+	sys = container_of(dwork, struct ipa_sys_context,
+			   rx.switch_to_intr_work);
+
+	/* For NAPI, interrupt mode is done in ipa_rx_poll context */
+	ipa_assert(!sys->ep->napi_enabled);
+
+	ipa_handle_rx(sys);
+}
+
+static struct ipa_sys_context *ipa_ep_sys_create(enum ipa_client_type client)
+{
+	const unsigned int wq_flags = WQ_MEM_RECLAIM | WQ_UNBOUND;
+	struct ipa_sys_context *sys;
+
+	/* Caller will zero all "mutable" fields; we fill in the rest */
+	sys = kmalloc(sizeof(*sys), GFP_KERNEL);
+	if (!sys)
+		return NULL;
+
+	sys->wq = alloc_workqueue("ipawq%u", wq_flags, 1, (u32)client);
+	if (!sys->wq) {
+		kfree(sys);
+		return NULL;
+	}
+
+	/* Caller assigns sys->ep = ep */
+	INIT_LIST_HEAD(&sys->head_desc_list);
+	spin_lock_init(&sys->spinlock);
+
+	return sys;
+}
+
+/**
+ * ipa_tx_dp_complete() - Transmit complete callback
+ * @user1:	Caller-supplied pointer value
+ * @user2:	Caller-supplied integer value
+ *
+ * Calls the endpoint's client_notify function if it exists;
+ * otherwise just frees the socket buffer (supplied in user1).
+ */
+static void ipa_tx_dp_complete(void *user1, int user2)
+{
+	struct sk_buff *skb = user1;
+	int ep_id = user2;
+
+	if (ipa_ctx->ep[ep_id].client_notify) {
+		unsigned long data;
+		void *priv;
+
+		priv = ipa_ctx->ep[ep_id].priv;
+		data = (unsigned long)skb;
+		ipa_ctx->ep[ep_id].client_notify(priv, IPA_WRITE_DONE, data);
+	} else {
+		dev_kfree_skb_any(skb);
+	}
+}
+
+/**
+ * ipa_tx_dp() - Transmit a socket buffer for APPS_WAN_PROD
+ * @client:	IPA client that is sending packets (WAN producer)
+ * @skb:	The socket buffer to send
+ *
+ * Returns:	0 if successful, or a negative error code
+ */
+int ipa_tx_dp(enum ipa_client_type client, struct sk_buff *skb)
+{
+	struct ipa_desc _desc = { };	/* Used for common case */
+	struct ipa_desc *desc;
+	u32 tlv_count;
+	int data_idx;
+	u32 nr_frags;
+	u32 ep_id;
+	int ret;
+	u32 f;
+
+	if (!skb->len)
+		return -EINVAL;
+
+	ep_id = ipa_client_ep_id(client);
+
+	/* Make sure source endpoint's TLV FIFO has enough entries to
+	 * hold the linear portion of the skb and all its frags.
+	 * If not, see if we can linearize it before giving up.
+	 */
+	nr_frags = skb_shinfo(skb)->nr_frags;
+	tlv_count = ipa_client_tlv_count(client);
+	if (1 + nr_frags > tlv_count) {
+		if (skb_linearize(skb))
+			return -ENOMEM;
+		nr_frags = 0;
+	}
+	if (nr_frags) {
+		desc = kcalloc(1 + nr_frags, sizeof(*desc), GFP_ATOMIC);
+		if (!desc)
+			return -ENOMEM;
+	} else {
+		desc = &_desc;	/* Default, linear case */
+	}
+
+	/* Fill in the IPA request descriptors--one for the linear
+	 * data in the skb, one each for each of its fragments.
+	 */
+	data_idx = 0;
+	desc[data_idx].payload = skb->data;
+	desc[data_idx].len_opcode = skb_headlen(skb);
+	desc[data_idx].type = IPA_DATA_DESC_SKB;
+	for (f = 0; f < nr_frags; f++) {
+		data_idx++;
+		desc[data_idx].payload = &skb_shinfo(skb)->frags[f];
+		desc[data_idx].type = IPA_DATA_DESC_SKB_PAGED;
+		desc[data_idx].len_opcode =
+				skb_frag_size(desc[data_idx].payload);
+	}
+
+	/* Have the skb be freed after the last descriptor completes. */
+	desc[data_idx].callback = ipa_tx_dp_complete;
+	desc[data_idx].user1 = skb;
+	desc[data_idx].user2 = ep_id;
+
+	ret = ipa_send(ipa_ctx->ep[ep_id].sys, data_idx + 1, desc);
+
+	if (nr_frags)
+		kfree(desc);
+
+	return ret;
+}
+
+static void ipa_wq_handle_rx(struct work_struct *work)
+{
+	struct ipa_sys_context *sys;
+
+	sys = container_of(work, struct ipa_sys_context, rx.work);
+
+	if (sys->ep->napi_enabled) {
+		ipa_client_add();
+		sys->ep->client_notify(sys->ep->priv, IPA_CLIENT_START_POLL, 0);
+	} else {
+		ipa_handle_rx(sys);
+	}
+}
+
+static int
+queue_rx_cache(struct ipa_sys_context *sys, struct ipa_rx_pkt_wrapper *rx_pkt)
+{
+	struct gsi_xfer_elem gsi_xfer_elem;
+	bool ring_doorbell;
+	int ret;
+
+	/* Don't bother zeroing this; we fill all fields */
+	gsi_xfer_elem.addr = rx_pkt->dma_addr;
+	gsi_xfer_elem.len_opcode = sys->rx.buff_sz;
+	gsi_xfer_elem.flags = GSI_XFER_FLAG_EOT;
+	gsi_xfer_elem.flags |= GSI_XFER_FLAG_EOB;
+	gsi_xfer_elem.type = GSI_XFER_ELEM_DATA;
+	gsi_xfer_elem.user_data = rx_pkt;
+
+	/* Doorbell is expensive; only ring it when a batch is queued */
+	ring_doorbell = sys->rx.len_pending_xfer++ >= IPA_REPL_XFER_THRESH;
+
+	ret = gsi_channel_queue(ipa_ctx->gsi, sys->ep->channel_id,
+				1, &gsi_xfer_elem, ring_doorbell);
+	if (ret)
+		return ret;
+
+	if (ring_doorbell)
+		sys->rx.len_pending_xfer = 0;
+
+	return 0;
+}
+
+/**
+ * ipa_replenish_rx_cache() - Replenish the Rx packets cache.
+ * @sys:	System context for IPA->AP endpoint
+ *
+ * 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_replenish_rx_cache(struct ipa_sys_context *sys)
+{
+	struct ipa_rx_pkt_wrapper *rx_pkt;
+	struct device *dev = ipa_ctx->dev;
+	u32 rx_len_cached = sys->len;
+
+	while (rx_len_cached < sys->rx.pool_sz) {
+		gfp_t flag = GFP_NOWAIT | __GFP_NOWARN;
+		void *ptr;
+		int ret;
+
+		rx_pkt = kmem_cache_zalloc(ipa_ctx->dp->rx_pkt_wrapper_cache,
+					   flag);
+		if (!rx_pkt)
+			goto fail_kmem_cache_alloc;
+
+		INIT_LIST_HEAD(&rx_pkt->link);
+
+		rx_pkt->skb = __dev_alloc_skb(sys->rx.buff_sz, flag);
+		if (!rx_pkt->skb) {
+			ipa_err("failed to alloc skb\n");
+			goto fail_skb_alloc;
+		}
+		ptr = skb_put(rx_pkt->skb, sys->rx.buff_sz);
+		rx_pkt->dma_addr = dma_map_single(dev, ptr, sys->rx.buff_sz,
+						  DMA_FROM_DEVICE);
+		if (dma_mapping_error(dev, rx_pkt->dma_addr)) {
+			ipa_err("dma_map_single failure %p for %p\n",
+				(void *)rx_pkt->dma_addr, ptr);
+			goto fail_dma_mapping;
+		}
+
+		list_add_tail(&rx_pkt->link, &sys->head_desc_list);
+		rx_len_cached = ++sys->len;
+
+		ret = queue_rx_cache(sys, rx_pkt);
+		if (ret)
+			goto fail_provide_rx_buffer;
+	}
+
+	return;
+
+fail_provide_rx_buffer:
+	list_del(&rx_pkt->link);
+	rx_len_cached = --sys->len;
+	dma_unmap_single(dev, rx_pkt->dma_addr, sys->rx.buff_sz,
+			 DMA_FROM_DEVICE);
+fail_dma_mapping:
+	dev_kfree_skb_any(rx_pkt->skb);
+fail_skb_alloc:
+	kmem_cache_free(ipa_ctx->dp->rx_pkt_wrapper_cache, rx_pkt);
+fail_kmem_cache_alloc:
+	if (rx_len_cached - sys->rx.len_pending_xfer == 0)
+		queue_delayed_work(sys->wq, &sys->rx.replenish_work,
+				   msecs_to_jiffies(1));
+}
+
+static void ipa_replenish_rx_work_func(struct work_struct *work)
+{
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct ipa_sys_context *sys;
+
+	sys = container_of(dwork, struct ipa_sys_context, rx.replenish_work);
+	ipa_client_add();
+	ipa_replenish_rx_cache(sys);
+	ipa_client_remove();
+}
+
+/** ipa_cleanup_rx() - release RX queue resources */
+static void ipa_cleanup_rx(struct ipa_sys_context *sys)
+{
+	struct ipa_rx_pkt_wrapper *rx_pkt;
+	struct ipa_rx_pkt_wrapper *r;
+
+	list_for_each_entry_safe(rx_pkt, r, &sys->head_desc_list, link) {
+		list_del(&rx_pkt->link);
+		dma_unmap_single(ipa_ctx->dev, rx_pkt->dma_addr,
+				 sys->rx.buff_sz, DMA_FROM_DEVICE);
+		dev_kfree_skb_any(rx_pkt->skb);
+		kmem_cache_free(ipa_ctx->dp->rx_pkt_wrapper_cache, rx_pkt);
+	}
+}
+
+static struct sk_buff *ipa_skb_copy_for_client(struct sk_buff *skb, int len)
+{
+	struct sk_buff *skb2;
+
+	skb2 = __dev_alloc_skb(len + IPA_RX_BUFF_CLIENT_HEADROOM, GFP_KERNEL);
+	if (likely(skb2)) {
+		/* Set the data pointer */
+		skb_reserve(skb2, IPA_RX_BUFF_CLIENT_HEADROOM);
+		memcpy(skb2->data, skb->data, len);
+		skb2->len = len;
+		skb_set_tail_pointer(skb2, len);
+	}
+
+	return skb2;
+}
+
+static struct sk_buff *ipa_join_prev_skb(struct sk_buff *prev_skb,
+					 struct sk_buff *skb, unsigned int len)
+{
+	struct sk_buff *skb2;
+
+	skb2 = skb_copy_expand(prev_skb, 0, len, GFP_KERNEL);
+	if (likely(skb2))
+		memcpy(skb_put(skb2, len), skb->data, len);
+	else
+		ipa_err("copy expand failed\n");
+	dev_kfree_skb_any(prev_skb);
+
+	return skb2;
+}
+
+static bool ipa_status_opcode_supported(enum ipahal_pkt_status_opcode opcode)
+{
+	return opcode == IPAHAL_PKT_STATUS_OPCODE_PACKET ||
+		opcode == IPAHAL_PKT_STATUS_OPCODE_DROPPED_PACKET ||
+		opcode == IPAHAL_PKT_STATUS_OPCODE_SUSPENDED_PACKET ||
+		opcode == IPAHAL_PKT_STATUS_OPCODE_PACKET_2ND_PASS;
+}
+
+static void
+ipa_lan_rx_pyld_hdlr(struct sk_buff *skb, struct ipa_sys_context *sys)
+{
+	struct ipahal_pkt_status status;
+	struct sk_buff *skb2;
+	unsigned long unused;
+	unsigned int align;
+	unsigned int used;
+	unsigned char *buf;
+	u32 pkt_status_sz;
+	int pad_len_byte;
+	u32 ep_id;
+	int len;
+	int len2;
+
+	pkt_status_sz = ipahal_pkt_status_get_size();
+	used = *(unsigned int *)skb->cb;
+	align = ALIGN(used, 32);
+	unused = IPA_RX_BUFFER_SIZE - used;
+
+	ipa_assert(skb->len);
+
+	if (sys->rx.len_partial) {
+		buf = skb_push(skb, sys->rx.len_partial);
+		memcpy(buf, sys->rx.prev_skb->data, sys->rx.len_partial);
+		sys->rx.len_partial = 0;
+		dev_kfree_skb_any(sys->rx.prev_skb);
+		sys->rx.prev_skb = NULL;
+		goto begin;
+	}
+
+	/* this endpoint has TX comp (status only) + mux-ed LAN RX data
+	 * (status+data)
+	 */
+	if (sys->rx.len_rem) {
+		if (sys->rx.len_rem <= skb->len) {
+			if (sys->rx.prev_skb) {
+				skb2 = skb_copy_expand(sys->rx.prev_skb, 0,
+						       sys->rx.len_rem,
+						       GFP_KERNEL);
+				if (likely(skb2)) {
+					memcpy(skb_put(skb2, sys->rx.len_rem),
+					       skb->data, sys->rx.len_rem);
+					skb_trim(skb2,
+						 skb2->len - sys->rx.len_pad);
+					skb2->truesize = skb2->len +
+						sizeof(struct sk_buff);
+					if (sys->rx.drop_packet)
+						dev_kfree_skb_any(skb2);
+					else
+						sys->ep->client_notify(
+							sys->ep->priv,
+							IPA_RECEIVE,
+							(unsigned long)(skb2));
+				} else {
+					ipa_err("copy expand failed\n");
+				}
+				dev_kfree_skb_any(sys->rx.prev_skb);
+			}
+			skb_pull(skb, sys->rx.len_rem);
+			sys->rx.prev_skb = NULL;
+			sys->rx.len_rem = 0;
+			sys->rx.len_pad = 0;
+		} else {
+			if (sys->rx.prev_skb) {
+				skb2 = ipa_join_prev_skb(sys->rx.prev_skb, skb,
+							 skb->len);
+				dev_kfree_skb_any(sys->rx.prev_skb);
+				sys->rx.prev_skb = skb2;
+			}
+			sys->rx.len_rem -= skb->len;
+			return;
+		}
+	}
+
+begin:
+	while (skb->len) {
+		sys->rx.drop_packet = false;
+
+		if (skb->len < pkt_status_sz) {
+			WARN_ON(sys->rx.prev_skb);
+			sys->rx.prev_skb = skb_copy(skb, GFP_KERNEL);
+			sys->rx.len_partial = skb->len;
+			return;
+		}
+
+		ipahal_pkt_status_parse(skb->data, &status);
+
+		if (!ipa_status_opcode_supported(status.status_opcode)) {
+			ipa_err("unsupported opcode(%d)\n",
+				status.status_opcode);
+			skb_pull(skb, pkt_status_sz);
+			continue;
+		}
+
+		if (status.pkt_len == 0) {
+			skb_pull(skb, pkt_status_sz);
+			continue;
+		}
+
+		if (status.endp_dest_idx == (sys->ep - ipa_ctx->ep)) {
+			/* RX data */
+			ep_id = status.endp_src_idx;
+
+			/* A packet which is received back to the AP after
+			 * there was no route match.
+			 */
+
+			if (status.exception ==
+				IPAHAL_PKT_STATUS_EXCEPTION_NONE &&
+			    status.rt_miss)
+				sys->rx.drop_packet = true;
+			if (skb->len == pkt_status_sz &&
+			    status.exception ==
+					IPAHAL_PKT_STATUS_EXCEPTION_NONE) {
+				WARN_ON(sys->rx.prev_skb);
+				sys->rx.prev_skb = skb_copy(skb, GFP_KERNEL);
+				sys->rx.len_partial = skb->len;
+				return;
+			}
+
+			pad_len_byte = ((status.pkt_len + 3) & ~3) -
+					status.pkt_len;
+
+			len = status.pkt_len + pad_len_byte +
+				IPA_SIZE_DL_CSUM_META_TRAILER;
+
+			if (status.exception ==
+					IPAHAL_PKT_STATUS_EXCEPTION_DEAGGR) {
+				sys->rx.drop_packet = true;
+			}
+
+			len2 = min(status.pkt_len + pkt_status_sz, skb->len);
+			skb2 = ipa_skb_copy_for_client(skb, len2);
+			if (likely(skb2)) {
+				if (skb->len < len + pkt_status_sz) {
+					sys->rx.prev_skb = skb2;
+					sys->rx.len_rem = len - skb->len +
+						pkt_status_sz;
+					sys->rx.len_pad = pad_len_byte;
+					skb_pull(skb, skb->len);
+				} else {
+					skb_trim(skb2, status.pkt_len +
+							pkt_status_sz);
+					if (sys->rx.drop_packet) {
+						dev_kfree_skb_any(skb2);
+					} else {
+						skb2->truesize =
+							skb2->len +
+							sizeof(struct sk_buff) +
+							(ALIGN(len +
+							pkt_status_sz, 32) *
+							unused / align);
+						sys->ep->client_notify(
+							sys->ep->priv,
+							IPA_RECEIVE,
+							(unsigned long)(skb2));
+					}
+					skb_pull(skb, len + pkt_status_sz);
+				}
+			} else {
+				ipa_err("fail to alloc skb\n");
+				if (skb->len < len) {
+					sys->rx.prev_skb = NULL;
+					sys->rx.len_rem = len - skb->len +
+						pkt_status_sz;
+					sys->rx.len_pad = pad_len_byte;
+					skb_pull(skb, skb->len);
+				} else {
+					skb_pull(skb, len + pkt_status_sz);
+				}
+			}
+		} else {
+			skb_pull(skb, pkt_status_sz);
+		}
+	}
+}
+
+static void
+ipa_wan_rx_handle_splt_pyld(struct sk_buff *skb, struct ipa_sys_context *sys)
+{
+	struct sk_buff *skb2;
+
+	if (sys->rx.len_rem <= skb->len) {
+		if (sys->rx.prev_skb) {
+			skb2 = ipa_join_prev_skb(sys->rx.prev_skb, skb,
+						 sys->rx.len_rem);
+			if (likely(skb2)) {
+				skb_pull(skb2, ipahal_pkt_status_get_size());
+				skb2->truesize = skb2->len +
+					sizeof(struct sk_buff);
+				sys->ep->client_notify(sys->ep->priv,
+						       IPA_RECEIVE,
+						       (unsigned long)skb2);
+			}
+		}
+		skb_pull(skb, sys->rx.len_rem);
+		sys->rx.prev_skb = NULL;
+		sys->rx.len_rem = 0;
+	} else {
+		if (sys->rx.prev_skb) {
+			skb2 = ipa_join_prev_skb(sys->rx.prev_skb, skb,
+						 skb->len);
+			sys->rx.prev_skb = skb2;
+		}
+		sys->rx.len_rem -= skb->len;
+		skb_pull(skb, skb->len);
+	}
+}
+
+static void
+ipa_wan_rx_pyld_hdlr(struct sk_buff *skb, struct ipa_sys_context *sys)
+{
+	struct ipahal_pkt_status status;
+	unsigned char *skb_data;
+	struct sk_buff *skb2;
+	u16 pkt_len_with_pad;
+	unsigned long unused;
+	unsigned int align;
+	unsigned int used;
+	u32 pkt_status_sz;
+	int frame_len;
+	u32 qmap_hdr;
+	int checksum;
+	int ep_id;
+
+	used = *(unsigned int *)skb->cb;
+	align = ALIGN(used, 32);
+	unused = IPA_RX_BUFFER_SIZE - used;
+
+	ipa_assert(skb->len);
+
+	if (ipa_ctx->ipa_client_apps_wan_cons_agg_gro) {
+		sys->ep->client_notify(sys->ep->priv, IPA_RECEIVE,
+				       (unsigned long)(skb));
+		return;
+	}
+
+	/* payload splits across 2 buff or more,
+	 * take the start of the payload from rx.prev_skb
+	 */
+	if (sys->rx.len_rem)
+		ipa_wan_rx_handle_splt_pyld(skb, sys);
+
+	pkt_status_sz = ipahal_pkt_status_get_size();
+	while (skb->len) {
+		u32 status_mask;
+
+		if (skb->len < pkt_status_sz) {
+			ipa_err("status straddles buffer\n");
+			WARN_ON(1);
+			goto bail;
+		}
+		ipahal_pkt_status_parse(skb->data, &status);
+		skb_data = skb->data;
+
+		if (!ipa_status_opcode_supported(status.status_opcode) ||
+		    status.status_opcode ==
+				IPAHAL_PKT_STATUS_OPCODE_SUSPENDED_PACKET) {
+			ipa_err("unsupported opcode(%d)\n",
+				status.status_opcode);
+			skb_pull(skb, pkt_status_sz);
+			continue;
+		}
+
+		if (status.endp_dest_idx >= ipa_ctx->ep_count ||
+		    status.endp_src_idx >= ipa_ctx->ep_count ||
+		    status.pkt_len > IPA_GENERIC_AGGR_BYTE_LIMIT) {
+			ipa_err("status fields invalid\n");
+			WARN_ON(1);
+			goto bail;
+		}
+		if (status.pkt_len == 0) {
+			skb_pull(skb, pkt_status_sz);
+			continue;
+		}
+		ep_id = ipa_client_ep_id(IPA_CLIENT_APPS_WAN_CONS);
+		if (status.endp_dest_idx != ep_id) {
+			ipa_err("expected endp_dest_idx %d received %d\n",
+				ep_id, status.endp_dest_idx);
+			WARN_ON(1);
+			goto bail;
+		}
+		/* RX data */
+		if (skb->len == pkt_status_sz) {
+			ipa_err("Ins header in next buffer\n");
+			WARN_ON(1);
+			goto bail;
+		}
+		qmap_hdr = *(u32 *)(skb_data + pkt_status_sz);
+
+		/* Take the pkt_len_with_pad from the last 2 bytes of the QMAP
+		 * header
+		 */
+		/*QMAP is BE: convert the pkt_len field from BE to LE*/
+		pkt_len_with_pad = ntohs((qmap_hdr >> 16) & 0xffff);
+		/*get the CHECKSUM_PROCESS bit*/
+		status_mask = status.status_mask;
+		checksum = status_mask & IPAHAL_PKT_STATUS_MASK_CKSUM_PROCESS;
+
+		frame_len = pkt_status_sz + IPA_QMAP_HEADER_LENGTH +
+			    pkt_len_with_pad;
+		if (checksum)
+			frame_len += IPA_DL_CHECKSUM_LENGTH;
+
+		skb2 = skb_clone(skb, GFP_ATOMIC);
+		if (likely(skb2)) {
+			/* the len of actual data is smaller than expected
+			 * payload split across 2 buff
+			 */
+			if (skb->len < frame_len) {
+				sys->rx.prev_skb = skb2;
+				sys->rx.len_rem = frame_len - skb->len;
+				skb_pull(skb, skb->len);
+			} else {
+				skb_trim(skb2, frame_len);
+				skb_pull(skb2, pkt_status_sz);
+				skb2->truesize = skb2->len +
+					sizeof(struct sk_buff) +
+					(ALIGN(frame_len, 32) *
+					 unused / align);
+				sys->ep->client_notify(sys->ep->priv,
+						       IPA_RECEIVE,
+						       (unsigned long)(skb2));
+				skb_pull(skb, frame_len);
+			}
+		} else {
+			ipa_err("fail to clone\n");
+			if (skb->len < frame_len) {
+				sys->rx.prev_skb = NULL;
+				sys->rx.len_rem = frame_len - skb->len;
+				skb_pull(skb, skb->len);
+			} else {
+				skb_pull(skb, frame_len);
+			}
+		}
+	}
+bail:
+	dev_kfree_skb_any(skb);
+}
+
+void ipa_lan_rx_cb(void *priv, enum ipa_dp_evt_type evt, unsigned long data)
+{
+	struct sk_buff *rx_skb = (struct sk_buff *)data;
+	struct ipahal_pkt_status status;
+	struct ipa_ep_context *ep;
+	u32 pkt_status_size;
+	u32 metadata;
+	u32 ep_id;
+
+	pkt_status_size = ipahal_pkt_status_get_size();
+
+	ipa_assert(rx_skb->len >= pkt_status_size);
+
+	ipahal_pkt_status_parse(rx_skb->data, &status);
+	ep_id = status.endp_src_idx;
+	metadata = status.metadata;
+	ep = &ipa_ctx->ep[ep_id];
+	if (ep_id >= ipa_ctx->ep_count || !ep->allocated ||
+	    !ep->client_notify) {
+		ipa_err("drop endpoint=%u allocated=%s client_notify=%p\n",
+			ep_id, ep->allocated ? "true" : "false",
+			ep->client_notify);
+		dev_kfree_skb_any(rx_skb);
+		return;
+	}
+
+	/* Consume the status packet, and if no exception, the header */
+	skb_pull(rx_skb, pkt_status_size);
+	if (status.exception == IPAHAL_PKT_STATUS_EXCEPTION_NONE)
+		skb_pull(rx_skb, IPA_LAN_RX_HEADER_LENGTH);
+
+	/* Metadata Info
+	 *  ------------------------------------------
+	 *  |	3     |	  2	|    1	      |	 0   |
+	 *  | fw_desc | vdev_id | qmap mux id | Resv |
+	 *  ------------------------------------------
+	 */
+	*(u16 *)rx_skb->cb = ((metadata >> 16) & 0xffff);
+
+	ep->client_notify(ep->priv, IPA_RECEIVE, (unsigned long)rx_skb);
+}
+
+static void ipa_rx_common(struct ipa_sys_context *sys, u32 size)
+{
+	struct ipa_rx_pkt_wrapper *rx_pkt;
+	struct sk_buff *rx_skb;
+
+	ipa_assert(!list_empty(&sys->head_desc_list));
+
+	spin_lock_bh(&sys->spinlock);
+
+	rx_pkt = list_first_entry(&sys->head_desc_list,
+				  struct ipa_rx_pkt_wrapper, link);
+	list_del(&rx_pkt->link);
+	sys->len--;
+
+	spin_unlock_bh(&sys->spinlock);
+
+	rx_skb = rx_pkt->skb;
+	dma_unmap_single(ipa_ctx->dev, rx_pkt->dma_addr, sys->rx.buff_sz,
+			 DMA_FROM_DEVICE);
+
+	skb_trim(rx_skb, size);
+
+	*(unsigned int *)rx_skb->cb = rx_skb->len;
+	rx_skb->truesize = size + sizeof(struct sk_buff);
+
+	sys->rx.pyld_hdlr(rx_skb, sys);
+	kmem_cache_free(ipa_ctx->dp->rx_pkt_wrapper_cache, rx_pkt);
+	ipa_replenish_rx_cache(sys);
+}
+
+/**
+ * ipa_aggr_byte_limit_buf_size()
+ * @byte_limit:	Desired limit (in bytes) for aggregation
+ *
+ * Compute the buffer size required to support a requested aggregation
+ * byte limit.  Aggregration will close when *more* than the configured
+ * number of bytes have been added to an aggregation frame.  Our
+ * buffers therefore need to to be big enough to receive one complete
+ * packet once the configured byte limit has been consumed.
+ *
+ * An incoming packet can have as much as IPA_MTU of data in it, but
+ * the buffer also needs to be large enough to accomodate the standard
+ * socket buffer overhead (NET_SKB_PAD of headroom, plus an implied
+ * skb_shared_info structure at the end).
+ *
+ * So we compute the required buffer size by adding the standard
+ * socket buffer overhead and MTU to the requested size.  We round
+ * that down to a power of 2 in an effort to avoid fragmentation due
+ * to unaligned buffer sizes.
+ *
+ * After accounting for all of this, we return the number of bytes
+ * of buffer space the IPA hardware will know is available to hold
+ * received data (without any overhead).
+ *
+ * Return:	The computes size of buffer space available
+ */
+u32 ipa_aggr_byte_limit_buf_size(u32 byte_limit)
+{
+	/* Account for one additional packet, including overhead */
+	byte_limit += IPA_RX_BUFFER_RESERVED;
+	byte_limit += IPA_MTU;
+
+	/* Convert this size to a nearby power-of-2.  We choose one
+	 * that's *less than* the limit we seek--so we start by
+	 * subracting 1.  The highest set bit in that is used to
+	 * compute the power of 2.
+	 *
+	 * XXX Why is this *less than* and not possibly equal?
+	 */
+	byte_limit = 1 << __fls(byte_limit - 1);
+
+	/* Given that size, figure out how much buffer space that
+	 * leaves us for received data.
+	 */
+	return IPA_RX_BUFFER_AVAILABLE(byte_limit);
+}
+
+void ipa_gsi_irq_tx_notify_cb(void *xfer_data)
+{
+	struct ipa_tx_pkt_wrapper *tx_pkt = xfer_data;
+
+	queue_work(tx_pkt->sys->wq, &tx_pkt->done_work);
+}
+
+void ipa_gsi_irq_rx_notify_cb(void *chan_data, u16 count)
+{
+	struct ipa_sys_context *sys = chan_data;
+
+	sys->ep->bytes_xfered_valid = true;
+	sys->ep->bytes_xfered = count;
+
+	ipa_rx_switch_to_poll_mode(sys);
+}
+
+static int ipa_gsi_setup_channel(struct ipa_ep_context *ep, u32 channel_count,
+				 u32 evt_ring_mult)
+{
+	u32 channel_id = ipa_client_channel_id(ep->client);
+	u32 tlv_count = ipa_client_tlv_count(ep->client);
+	bool from_ipa = ipa_consumer(ep->client);
+	bool moderation;
+	bool priority;
+	int ret;
+
+	priority = ep->client == IPA_CLIENT_APPS_CMD_PROD;
+	moderation = !ep->sys->tx.no_intr;
+
+	ret = gsi_channel_alloc(ipa_ctx->gsi, channel_id, channel_count,
+				from_ipa, priority, evt_ring_mult, moderation,
+				ep->sys);
+	if (ret)
+		return ret;
+	ep->channel_id = channel_id;
+
+	gsi_channel_scratch_write(ipa_ctx->gsi, ep->channel_id, tlv_count);
+
+	ret = gsi_channel_start(ipa_ctx->gsi, ep->channel_id);
+	if (ret)
+		gsi_channel_free(ipa_ctx->gsi, ep->channel_id);
+
+	return ret;
+}
+
+void ipa_endp_init_hdr_cons(u32 ep_id, u32 header_size,
+			    u32 metadata_offset, u32 length_offset)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_hdr_cons(&ep->init_hdr, header_size, metadata_offset,
+				   length_offset);
+}
+
+void ipa_endp_init_hdr_prod(u32 ep_id, u32 header_size,
+			    u32 metadata_offset, u32 length_offset)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_hdr_prod(&ep->init_hdr, header_size, metadata_offset,
+				   length_offset);
+}
+
+void
+ipa_endp_init_hdr_ext_cons(u32 ep_id, u32 pad_align, bool pad_included)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_hdr_ext_cons(&ep->hdr_ext, pad_align, pad_included);
+}
+
+void ipa_endp_init_hdr_ext_prod(u32 ep_id, u32 pad_align)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_hdr_ext_prod(&ep->hdr_ext, pad_align);
+}
+
+void
+ipa_endp_init_aggr_cons(u32 ep_id, u32 size, u32 count, bool close_on_eof)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_aggr_cons(&ep->init_aggr, size, count, close_on_eof);
+}
+
+void ipa_endp_init_aggr_prod(u32 ep_id, enum ipa_aggr_en aggr_en,
+			     enum ipa_aggr_type aggr_type)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_aggr_prod(&ep->init_aggr, aggr_en, aggr_type);
+}
+
+void ipa_endp_init_cfg_cons(u32 ep_id, enum ipa_cs_offload_en offload_type)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_cfg_cons(&ep->init_cfg, offload_type);
+}
+
+void ipa_endp_init_cfg_prod(u32 ep_id, enum ipa_cs_offload_en offload_type,
+			    u32 metadata_offset)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_cfg_prod(&ep->init_cfg, offload_type,
+				   metadata_offset);
+}
+
+void ipa_endp_init_hdr_metadata_mask_cons(u32 ep_id, u32 mask)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_hdr_metadata_mask_cons(&ep->metadata_mask, mask);
+}
+
+void ipa_endp_init_hdr_metadata_mask_prod(u32 ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_hdr_metadata_mask_prod(&ep->metadata_mask);
+}
+
+void ipa_endp_status_cons(u32 ep_id, bool enable)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_status_cons(&ep->status, enable);
+}
+
+void ipa_endp_status_prod(u32 ep_id, bool enable,
+			  enum ipa_client_type status_client)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+	u32 status_ep_id;
+
+	status_ep_id = ipa_client_ep_id(status_client);
+
+	ipa_reg_endp_status_prod(&ep->status, enable, status_ep_id);
+}
+
+
+/* Note that the mode setting is not valid for consumer endpoints */
+void ipa_endp_init_mode_cons(u32 ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_mode_cons(&ep->init_mode);
+}
+
+void ipa_endp_init_mode_prod(u32 ep_id, enum ipa_mode mode,
+			     enum ipa_client_type dst_client)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+	u32 dst_ep_id;
+
+	dst_ep_id = ipa_client_ep_id(dst_client);
+
+	ipa_reg_endp_init_mode_prod(&ep->init_mode, mode, dst_ep_id);
+}
+
+/* XXX The sequencer setting seems not to be valid for consumer endpoints */
+void ipa_endp_init_seq_cons(u32 ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_seq_cons(&ep->init_seq);
+}
+
+void ipa_endp_init_seq_prod(u32 ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+	u32 seq_type;
+
+	seq_type = (u32)ipa_endp_seq_type(ep_id);
+
+	ipa_reg_endp_init_seq_prod(&ep->init_seq, seq_type);
+}
+
+/* XXX The deaggr setting seems not to be valid for consumer endpoints */
+void ipa_endp_init_deaggr_cons(u32 ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_deaggr_cons(&ep->init_deaggr);
+}
+
+void ipa_endp_init_deaggr_prod(u32 ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_reg_endp_init_deaggr_prod(&ep->init_deaggr);
+}
+
+int ipa_ep_alloc(enum ipa_client_type client)
+{
+	u32 ep_id = ipa_client_ep_id(client);
+	struct ipa_sys_context *sys;
+	struct ipa_ep_context *ep;
+
+	ep = &ipa_ctx->ep[ep_id];
+
+	ipa_assert(!ep->allocated);
+
+	/* Reuse the endpoint's sys pointer if it is initialized */
+	sys = ep->sys;
+	if (!sys) {
+		sys = ipa_ep_sys_create(client);
+		if (!sys)
+			return -ENOMEM;
+		sys->ep = ep;
+	}
+
+	/* Zero the "mutable" part of the system context */
+	memset(sys, 0, offsetof(struct ipa_sys_context, ep));
+
+	/* Initialize the endpoint context */
+	memset(ep, 0, sizeof(*ep));
+	ep->sys = sys;
+	ep->client = client;
+	ep->allocated = true;
+
+	return ep_id;
+}
+
+void ipa_ep_free(u32 ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+
+	ipa_assert(ep->allocated);
+
+	ep->allocated = false;
+}
+
+/**
+ * ipa_ep_setup() - Set up an IPA endpoint
+ * @ep_id:		Endpoint to set up
+ * @channel_count:	Number of transfer elements in the channel
+ * @evt_ring_mult:	Used to determine number of elements in event ring
+ * @rx_buffer_size:	Receive buffer size to use (or 0 for TX endpoitns)
+ * @client_notify:	Notify function to call on completion
+ * @priv:		Value supplied to the notify function
+ *
+ * Returns:	0 if successful, or a negative error code
+ */
+int ipa_ep_setup(u32 ep_id, u32 channel_count, u32 evt_ring_mult,
+		 u32 rx_buffer_size,
+		 void (*client_notify)(void *priv, enum ipa_dp_evt_type type,
+				       unsigned long data),
+		 void *priv)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+	int ret;
+
+	if (ipa_consumer(ep->client)) {
+		atomic_set(&ep->sys->rx.curr_polling_state, 0);
+		INIT_DELAYED_WORK(&ep->sys->rx.switch_to_intr_work,
+				  ipa_switch_to_intr_rx_work_func);
+		if (ep->client == IPA_CLIENT_APPS_LAN_CONS)
+			ep->sys->rx.pyld_hdlr = ipa_lan_rx_pyld_hdlr;
+		else
+			ep->sys->rx.pyld_hdlr = ipa_wan_rx_pyld_hdlr;
+		ep->sys->rx.buff_sz = rx_buffer_size;
+		ep->sys->rx.pool_sz = IPA_GENERIC_RX_POOL_SZ;
+		INIT_WORK(&ep->sys->rx.work, ipa_wq_handle_rx);
+		INIT_DELAYED_WORK(&ep->sys->rx.replenish_work,
+				  ipa_replenish_rx_work_func);
+	}
+
+	ep->client_notify = client_notify;
+	ep->priv = priv;
+	ep->napi_enabled = ep->client == IPA_CLIENT_APPS_WAN_CONS;
+
+	ipa_client_add();
+
+	ipa_cfg_ep(ep_id);
+
+	ret = ipa_gsi_setup_channel(ep, channel_count, evt_ring_mult);
+	if (ret)
+		goto err_client_remove;
+
+	if (ipa_consumer(ep->client))
+		ipa_replenish_rx_cache(ep->sys);
+err_client_remove:
+	ipa_client_remove();
+
+	return ret;
+}
+
+/**
+ * ipa_channel_reset_aggr() - Reset with aggregation active
+ * @ep_id:	Endpoint on which reset is performed
+ *
+ * If aggregation is active on a channel when a reset is performed,
+ * a special sequence of actions must be taken.  This is a workaround
+ * for a hardware limitation.
+ *
+ * Return:	0 if successful, or a negative error code.
+ */
+static int ipa_channel_reset_aggr(u32 ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+	struct ipa_reg_aggr_force_close force_close;
+	struct ipa_reg_endp_init_ctrl init_ctrl;
+	struct gsi_xfer_elem xfer_elem = { };
+	struct ipa_dma_mem dma_byte;
+	int aggr_active_bitmap = 0;
+	bool ep_suspended = false;
+	int ret;
+	int i;
+
+	ipa_reg_aggr_force_close(&force_close, BIT(ep_id));
+	ipa_write_reg_fields(IPA_AGGR_FORCE_CLOSE, &force_close);
+
+	/* Reset channel */
+	ret = gsi_channel_reset(ipa_ctx->gsi, ep->channel_id);
+	if (ret)
+		return ret;
+
+	/* Turn off the doorbell engine.  We're going to poll until
+	 * we know aggregation isn't active.
+	 */
+	gsi_channel_config(ipa_ctx->gsi, ep->channel_id, false);
+
+	ipa_read_reg_n_fields(IPA_ENDP_INIT_CTRL_N, ep_id, &init_ctrl);
+	if (init_ctrl.endp_suspend) {
+		ep_suspended = true;
+		ipa_reg_endp_init_ctrl(&init_ctrl, false);
+		ipa_write_reg_n_fields(IPA_ENDP_INIT_CTRL_N, ep_id, &init_ctrl);
+	}
+
+	/* Start channel and put 1 Byte descriptor on it */
+	ret = gsi_channel_start(ipa_ctx->gsi, ep->channel_id);
+	if (ret)
+		goto out_suspend_again;
+
+	if (ipa_dma_alloc(&dma_byte, 1, GFP_KERNEL)) {
+		ret = -ENOMEM;
+		goto err_stop_channel;
+	}
+
+	xfer_elem.addr = dma_byte.phys;
+	xfer_elem.len_opcode = 1;	/* = dma_byte.size; */
+	xfer_elem.flags = GSI_XFER_FLAG_EOT;
+	xfer_elem.type = GSI_XFER_ELEM_DATA;
+
+	ret = gsi_channel_queue(ipa_ctx->gsi, ep->channel_id, 1, &xfer_elem,
+				true);
+	if (ret)
+		goto err_dma_free;
+
+	/* Wait for aggregation frame to be closed */
+	for (i = 0; i < CHANNEL_RESET_AGGR_RETRY_COUNT; i++) {
+		aggr_active_bitmap = ipa_read_reg(IPA_STATE_AGGR_ACTIVE);
+		if (!(aggr_active_bitmap & BIT(ep_id)))
+			break;
+		msleep(CHANNEL_RESET_DELAY);
+	}
+	ipa_bug_on(aggr_active_bitmap & BIT(ep_id));
+
+	ipa_dma_free(&dma_byte);
+
+	ret = ipa_stop_gsi_channel(ep_id);
+	if (ret)
+		goto out_suspend_again;
+
+	/* Reset the channel.  If successful we need to sleep for 1
+	 * msec to complete the GSI channel reset sequence.  Either
+	 * way we finish by suspending the channel again (if necessary)
+	 * and re-enabling its doorbell engine.
+	 */
+	ret = gsi_channel_reset(ipa_ctx->gsi, ep->channel_id);
+	if (!ret)
+		msleep(CHANNEL_RESET_DELAY);
+	goto out_suspend_again;
+
+err_dma_free:
+	ipa_dma_free(&dma_byte);
+err_stop_channel:
+	ipa_stop_gsi_channel(ep_id);
+out_suspend_again:
+	if (ep_suspended) {
+		ipa_reg_endp_init_ctrl(&init_ctrl, true);
+		ipa_write_reg_n_fields(IPA_ENDP_INIT_CTRL_N, ep_id, &init_ctrl);
+	}
+	/* Turn on the doorbell engine again */
+	gsi_channel_config(ipa_ctx->gsi, ep->channel_id, true);
+
+	return ret;
+}
+
+static void ipa_reset_gsi_channel(u32 ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+	u32 aggr_active_bitmap = 0;
+
+	/* For consumer endpoints, a hardware limitation prevents us
+	 * from issuing a channel reset if aggregation is active.
+	 * Check for this case, and if detected, perform a special
+	 * reset sequence.  Otherwise just do a "normal" reset.
+	 */
+	if (ipa_consumer(ep->client))
+		aggr_active_bitmap = ipa_read_reg(IPA_STATE_AGGR_ACTIVE);
+
+	if (aggr_active_bitmap & BIT(ep_id)) {
+		ipa_bug_on(ipa_channel_reset_aggr(ep_id));
+	} else {
+		/* In case the reset follows stop, need to wait 1 msec */
+		msleep(CHANNEL_RESET_DELAY);
+		ipa_bug_on(gsi_channel_reset(ipa_ctx->gsi, ep->channel_id));
+	}
+}
+
+/**
+ * ipa_ep_teardown() - Tear down an endpoint
+ * @ep_id:	The endpoint to tear down
+ */
+void ipa_ep_teardown(u32 ep_id)
+{
+	struct ipa_ep_context *ep = &ipa_ctx->ep[ep_id];
+	int empty;
+	int ret;
+	int i;
+
+	if (ep->napi_enabled) {
+		do {
+			usleep_range(95, 105);
+		} while (ipa_ep_polling(ep));
+	}
+
+	if (ipa_producer(ep->client)) {
+		do {
+			spin_lock_bh(&ep->sys->spinlock);
+			empty = list_empty(&ep->sys->head_desc_list);
+			spin_unlock_bh(&ep->sys->spinlock);
+			if (!empty)
+				usleep_range(95, 105);
+			else
+				break;
+		} while (1);
+	}
+
+	if (ipa_consumer(ep->client))
+		cancel_delayed_work_sync(&ep->sys->rx.replenish_work);
+	flush_workqueue(ep->sys->wq);
+	/* channel stop might fail on timeout if IPA is busy */
+	for (i = 0; i < IPA_GSI_CHANNEL_STOP_MAX_RETRY; i++) {
+		ret = ipa_stop_gsi_channel(ep_id);
+		if (!ret)
+			break;
+		ipa_bug_on(ret != -EAGAIN && ret != -ETIMEDOUT);
+	}
+
+	ipa_reset_gsi_channel(ep_id);
+	gsi_channel_free(ipa_ctx->gsi, ep->channel_id);
+
+	if (ipa_consumer(ep->client))
+		ipa_cleanup_rx(ep->sys);
+
+	ipa_ep_free(ep_id);
+}
+
+static int ipa_poll_gsi_pkt(struct ipa_sys_context *sys)
+{
+	if (sys->ep->bytes_xfered_valid) {
+		sys->ep->bytes_xfered_valid = false;
+
+		return (int)sys->ep->bytes_xfered;
+	}
+
+	return gsi_channel_poll(ipa_ctx->gsi, sys->ep->channel_id);
+}
+
+bool ipa_ep_polling(struct ipa_ep_context *ep)
+{
+	ipa_assert(ipa_consumer(ep->client));
+
+	return !!atomic_read(&ep->sys->rx.curr_polling_state);
+}
+
+struct ipa_dp *ipa_dp_init(void)
+{
+	struct kmem_cache *cache;
+	struct ipa_dp *dp;
+
+	dp = kzalloc(sizeof(*dp), GFP_KERNEL);
+	if (!dp)
+		return NULL;
+
+	cache = kmem_cache_create("IPA_TX_PKT_WRAPPER",
+				  sizeof(struct ipa_tx_pkt_wrapper),
+				  0, 0, NULL);
+	if (!cache) {
+		kfree(dp);
+		return NULL;
+	}
+	dp->tx_pkt_wrapper_cache = cache;
+
+	cache = kmem_cache_create("IPA_RX_PKT_WRAPPER",
+				  sizeof(struct ipa_rx_pkt_wrapper),
+				  0, 0, NULL);
+	if (!cache) {
+		kmem_cache_destroy(dp->tx_pkt_wrapper_cache);
+		kfree(dp);
+		return NULL;
+	}
+	dp->rx_pkt_wrapper_cache = cache;
+
+	return dp;
+}
+
+void ipa_dp_exit(struct ipa_dp *dp)
+{
+	kmem_cache_destroy(dp->rx_pkt_wrapper_cache);
+	kmem_cache_destroy(dp->tx_pkt_wrapper_cache);
+	kfree(dp);
+}
-- 
2.17.1


  parent reply index

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-07  0:32 [RFC PATCH 00/12] net: introduce Qualcomm IPA driver Alex Elder
2018-11-07  0:32 ` [RFC PATCH 01/12] dt-bindings: soc: qcom: add IPA bindings Alex Elder
2018-11-07 11:50   ` Arnd Bergmann
2018-11-09 22:38     ` Alex Elder
2018-11-07 14:59   ` Rob Herring
2018-11-09 22:38     ` Alex Elder
2018-11-11  1:40       ` Rob Herring
2018-11-13 16:28     ` Alex Elder
2018-11-07  0:32 ` [RFC PATCH 02/12] soc: qcom: ipa: DMA helpers Alex Elder
2018-11-07 12:17   ` Arnd Bergmann
2018-11-13 16:33     ` Alex Elder
2018-11-07  0:32 ` [RFC PATCH 03/12] soc: qcom: ipa: generic software interface Alex Elder
2018-11-07  0:32 ` [RFC PATCH 04/12] soc: qcom: ipa: immediate commands Alex Elder
2018-11-07 14:36   ` Arnd Bergmann
2018-11-13 16:58     ` Alex Elder
2018-11-07  0:32 ` [RFC PATCH 05/12] soc: qcom: ipa: IPA interrupts and the microcontroller Alex Elder
2018-11-07  0:32 ` [RFC PATCH 06/12] soc: qcom: ipa: QMI modem communication Alex Elder
2018-11-07  0:32 ` [RFC PATCH 07/12] soc: qcom: ipa: IPA register abstraction Alex Elder
2018-11-07 15:00   ` Arnd Bergmann
2018-11-15  2:48     ` Alex Elder
2018-11-15 14:42       ` Arnd Bergmann
2018-11-07  0:32 ` [RFC PATCH 08/12] soc: qcom: ipa: utility functions Alex Elder
2018-11-07  0:32 ` [RFC PATCH 09/12] soc: qcom: ipa: main IPA source file Alex Elder
2018-11-07 14:08   ` Arnd Bergmann
2018-11-15  3:11     ` Alex Elder
2018-11-07  0:32 ` Alex Elder [this message]
2018-11-07 14:55   ` [RFC PATCH 10/12] soc: qcom: ipa: data path Arnd Bergmann
2018-11-15  3:31     ` Alex Elder
2018-11-15 14:48       ` Arnd Bergmann
2018-11-07  0:32 ` [RFC PATCH 11/12] soc: qcom: ipa: IPA rmnet interface Alex Elder
2018-11-07 13:30   ` Arnd Bergmann
2018-11-07 15:26   ` Dan Williams
2018-11-07  0:32 ` [RFC PATCH 12/12] soc: qcom: ipa: build and "ipa_i.h" Alex Elder
2018-11-07  0:40   ` Randy Dunlap
2018-11-08 16:22     ` Alex Elder
2018-11-07 12:34   ` Arnd Bergmann
2018-11-07 15:46 ` [RFC PATCH 00/12] net: introduce Qualcomm IPA driver Arnd Bergmann

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