diff --git a/drivers/infiniband/hw/hfi1/pio.c b/drivers/infiniband/hw/hfi1/pio.c
new file mode 100644
index 0000000..6d89808
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/pio.c
@@ -0,0 +1,1764 @@
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  - Neither the name of Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/delay.h>
+#include "hfi.h"
+#include "qp.h"
+#include "trace.h"
+
+#define SC_CTXT_PACKET_EGRESS_TIMEOUT 350 /* in chip cycles */
+
+#define SC(name) SEND_CTXT_##name
+/*
+ * Send Context functions
+ */
+static void sc_wait_for_packet_egress(struct send_context *sc, int pause);
+
+/*
+ * Set the CM reset bit and wait for it to clear.  Use the provided
+ * sendctrl register.  This routine has no locking.
+ */
+void __cm_reset(struct hfi1_devdata *dd, u64 sendctrl)
+{
+	write_csr(dd, SEND_CTRL, sendctrl | SEND_CTRL_CM_RESET_SMASK);
+	while (1) {
+		udelay(1);
+		sendctrl = read_csr(dd, SEND_CTRL);
+		if ((sendctrl & SEND_CTRL_CM_RESET_SMASK) == 0)
+			break;
+	}
+}
+
+/* defined in header release 48 and higher */
+#ifndef SEND_CTRL_UNSUPPORTED_VL_SHIFT
+#define SEND_CTRL_UNSUPPORTED_VL_SHIFT 3
+#define SEND_CTRL_UNSUPPORTED_VL_MASK 0xffull
+#define SEND_CTRL_UNSUPPORTED_VL_SMASK (SEND_CTRL_UNSUPPORTED_VL_MASK \
+		<< SEND_CTRL_UNSUPPORTED_VL_SHIFT)
+#endif
+
+/* global control of PIO send */
+void pio_send_control(struct hfi1_devdata *dd, int op)
+{
+	u64 reg;
+	unsigned long flags;
+	int write = 1;	/* write sendctrl back */
+	int flush = 0;	/* re-read sendctrl to make sure it is flushed */
+
+	spin_lock_irqsave(&dd->sendctrl_lock, flags);
+
+	reg = read_csr(dd, SEND_CTRL);
+	switch (op) {
+	case PSC_GLOBAL_ENABLE:
+		reg |= SEND_CTRL_SEND_ENABLE_SMASK;
+		break;
+	case PSC_GLOBAL_DISABLE:
+		reg &= ~SEND_CTRL_SEND_ENABLE_SMASK;
+		break;
+	case PSC_GLOBAL_VLARB_ENABLE:
+		reg |= SEND_CTRL_VL_ARBITER_ENABLE_SMASK;
+		break;
+	case PSC_GLOBAL_VLARB_DISABLE:
+		reg &= ~SEND_CTRL_VL_ARBITER_ENABLE_SMASK;
+		break;
+	case PSC_CM_RESET:
+		__cm_reset(dd, reg);
+		write = 0; /* CSR already written (and flushed) */
+		break;
+	case PSC_DATA_VL_ENABLE:
+		reg &= ~SEND_CTRL_UNSUPPORTED_VL_SMASK;
+		break;
+	case PSC_DATA_VL_DISABLE:
+		reg |= SEND_CTRL_UNSUPPORTED_VL_SMASK;
+		flush = 1;
+		break;
+	default:
+		dd_dev_err(dd, "%s: invalid control %d\n", __func__, op);
+		break;
+	}
+
+	if (write) {
+		write_csr(dd, SEND_CTRL, reg);
+		if (flush)
+			(void) read_csr(dd, SEND_CTRL); /* flush write */
+	}
+
+	spin_unlock_irqrestore(&dd->sendctrl_lock, flags);
+}
+
+/* number of send context memory pools */
+#define NUM_SC_POOLS 2
+
+/* Send Context Size (SCS) wildcards */
+#define SCS_POOL_0 -1
+#define SCS_POOL_1 -2
+/* Send Context Count (SCC) wildcards */
+#define SCC_PER_VL -1
+#define SCC_PER_CPU  -2
+
+#define SCC_PER_KRCVQ  -3
+#define SCC_ACK_CREDITS  32
+
+#define PIO_WAIT_BATCH_SIZE 5
+
+/* default send context sizes */
+static struct sc_config_sizes sc_config_sizes[SC_MAX] = {
+	[SC_KERNEL] = { .size  = SCS_POOL_0,	/* even divide, pool 0 */
+			.count = SCC_PER_VL },/* one per NUMA */
+	[SC_ACK]    = { .size  = SCC_ACK_CREDITS,
+			.count = SCC_PER_KRCVQ },
+	[SC_USER]   = { .size  = SCS_POOL_0,	/* even divide, pool 0 */
+			.count = SCC_PER_CPU },	/* one per CPU */
+
+};
+
+/* send context memory pool configuration */
+struct mem_pool_config {
+	int centipercent;	/* % of memory, in 100ths of 1% */
+	int absolute_blocks;	/* absolute block count */
+};
+
+/* default memory pool configuration: 100% in pool 0 */
+static struct mem_pool_config sc_mem_pool_config[NUM_SC_POOLS] = {
+	/* centi%, abs blocks */
+	{  10000,     -1 },		/* pool 0 */
+	{      0,     -1 },		/* pool 1 */
+};
+
+/* memory pool information, used when calculating final sizes */
+struct mem_pool_info {
+	int centipercent;	/* 100th of 1% of memory to use, -1 if blocks
+				   already set */
+	int count;		/* count of contexts in the pool */
+	int blocks;		/* block size of the pool */
+	int size;		/* context size, in blocks */
+};
+
+/*
+ * Convert a pool wildcard to a valid pool index.  The wildcards
+ * start at -1 and increase negatively.  Map them as:
+ *	-1 => 0
+ *	-2 => 1
+ *	etc.
+ *
+ * Return -1 on non-wildcard input, otherwise convert to a pool number.
+ */
+static int wildcard_to_pool(int wc)
+{
+	if (wc >= 0)
+		return -1;	/* non-wildcard */
+	return -wc - 1;
+}
+
+static const char *sc_type_names[SC_MAX] = {
+	"kernel",
+	"ack",
+	"user"
+};
+
+static const char *sc_type_name(int index)
+{
+	if (index < 0 || index >= SC_MAX)
+		return "unknown";
+	return sc_type_names[index];
+}
+
+/*
+ * Read the send context memory pool configuration and send context
+ * size configuration.  Replace any wildcards and come up with final
+ * counts and sizes for the send context types.
+ */
+int init_sc_pools_and_sizes(struct hfi1_devdata *dd)
+{
+	struct mem_pool_info mem_pool_info[NUM_SC_POOLS] = { { 0 } };
+	int total_blocks = (dd->chip_pio_mem_size / PIO_BLOCK_SIZE) - 1;
+	int total_contexts = 0;
+	int fixed_blocks;
+	int pool_blocks;
+	int used_blocks;
+	int cp_total;		/* centipercent total */
+	int ab_total;		/* absolute block total */
+	int extra;
+	int i;
+
+	/*
+	 * Step 0:
+	 *	- copy the centipercents/absolute sizes from the pool config
+	 *	- sanity check these values
+	 *	- add up centipercents, then later check for full value
+	 *	- add up absolute blocks, then later check for over-commit
+	 */
+	cp_total = 0;
+	ab_total = 0;
+	for (i = 0; i < NUM_SC_POOLS; i++) {
+		int cp = sc_mem_pool_config[i].centipercent;
+		int ab = sc_mem_pool_config[i].absolute_blocks;
+
+		/*
+		 * A negative value is "unused" or "invalid".  Both *can*
+		 * be valid, but centipercent wins, so check that first
+		 */
+		if (cp >= 0) {			/* centipercent valid */
+			cp_total += cp;
+		} else if (ab >= 0) {		/* absolute blocks valid */
+			ab_total += ab;
+		} else {			/* neither valid */
+			dd_dev_err(
+				dd,
+				"Send context memory pool %d: both the block count and centipercent are invalid\n",
+				i);
+			return -EINVAL;
+		}
+
+		mem_pool_info[i].centipercent = cp;
+		mem_pool_info[i].blocks = ab;
+	}
+
+	/* do not use both % and absolute blocks for different pools */
+	if (cp_total != 0 && ab_total != 0) {
+		dd_dev_err(
+			dd,
+			"All send context memory pools must be described as either centipercent or blocks, no mixing between pools\n");
+		return -EINVAL;
+	}
+
+	/* if any percentages are present, they must add up to 100% x 100 */
+	if (cp_total != 0 && cp_total != 10000) {
+		dd_dev_err(
+			dd,
+			"Send context memory pool centipercent is %d, expecting 10000\n",
+			cp_total);
+		return -EINVAL;
+	}
+
+	/* the absolute pool total cannot be more than the mem total */
+	if (ab_total > total_blocks) {
+		dd_dev_err(
+			dd,
+			"Send context memory pool absolute block count %d is larger than the memory size %d\n",
+			ab_total, total_blocks);
+		return -EINVAL;
+	}
+
+	/*
+	 * Step 2:
+	 *	- copy from the context size config
+	 *	- replace context type wildcard counts with real values
+	 *	- add up non-memory pool block sizes
+	 *	- add up memory pool user counts
+	 */
+	fixed_blocks = 0;
+	for (i = 0; i < SC_MAX; i++) {
+		int count = sc_config_sizes[i].count;
+		int size = sc_config_sizes[i].size;
+		int pool;
+
+		/*
+		 * Sanity check count: Either a positive value or
+		 * one of the expected wildcards is valid.  The positive
+		 * value is checked later when we compare against total
+		 * memory available.
+		 */
+		if (i == SC_ACK) {
+			count = dd->n_krcv_queues;
+		} else if (i == SC_KERNEL) {
+			count = num_vls + 1 /* VL15 */;
+		} else if (count == SCC_PER_CPU) {
+			count = num_online_cpus();
+		} else if (count < 0) {
+			dd_dev_err(
+				dd,
+				"%s send context invalid count wildcard %d\n",
+				sc_type_name(i), count);
+			return -EINVAL;
+		}
+		if (total_contexts + count > dd->chip_send_contexts)
+			count = dd->chip_send_contexts - total_contexts;
+
+		total_contexts += count;
+
+		/*
+		 * Sanity check pool: The conversion will return a pool
+		 * number or -1 if a fixed (non-negative) value.  The fixed
+		 * value is checked later when we compare against
+		 * total memory available.
+		 */
+		pool = wildcard_to_pool(size);
+		if (pool == -1) {			/* non-wildcard */
+			fixed_blocks += size * count;
+		} else if (pool < NUM_SC_POOLS) {	/* valid wildcard */
+			mem_pool_info[pool].count += count;
+		} else {				/* invalid wildcard */
+			dd_dev_err(
+				dd,
+				"%s send context invalid pool wildcard %d\n",
+				sc_type_name(i), size);
+			return -EINVAL;
+		}
+
+		dd->sc_sizes[i].count = count;
+		dd->sc_sizes[i].size = size;
+	}
+	if (fixed_blocks > total_blocks) {
+		dd_dev_err(
+			dd,
+			"Send context fixed block count, %u, larger than total block count %u\n",
+			fixed_blocks, total_blocks);
+		return -EINVAL;
+	}
+
+	/* step 3: calculate the blocks in the pools, and pool context sizes */
+	pool_blocks = total_blocks - fixed_blocks;
+	if (ab_total > pool_blocks) {
+		dd_dev_err(
+			dd,
+			"Send context fixed pool sizes, %u, larger than pool block count %u\n",
+			ab_total, pool_blocks);
+		return -EINVAL;
+	}
+	/* subtract off the fixed pool blocks */
+	pool_blocks -= ab_total;
+
+	for (i = 0; i < NUM_SC_POOLS; i++) {
+		struct mem_pool_info *pi = &mem_pool_info[i];
+
+		/* % beats absolute blocks */
+		if (pi->centipercent >= 0)
+			pi->blocks = (pool_blocks * pi->centipercent) / 10000;
+
+		if (pi->blocks == 0 && pi->count != 0) {
+			dd_dev_err(
+				dd,
+				"Send context memory pool %d has %u contexts, but no blocks\n",
+				i, pi->count);
+			return -EINVAL;
+		}
+		if (pi->count == 0) {
+			/* warn about wasted blocks */
+			if (pi->blocks != 0)
+				dd_dev_err(
+					dd,
+					"Send context memory pool %d has %u blocks, but zero contexts\n",
+					i, pi->blocks);
+			pi->size = 0;
+		} else {
+			pi->size = pi->blocks / pi->count;
+		}
+	}
+
+	/* step 4: fill in the context type sizes from the pool sizes */
+	used_blocks = 0;
+	for (i = 0; i < SC_MAX; i++) {
+		if (dd->sc_sizes[i].size < 0) {
+			unsigned pool = wildcard_to_pool(dd->sc_sizes[i].size);
+
+			BUG_ON(pool >= NUM_SC_POOLS);
+			dd->sc_sizes[i].size = mem_pool_info[pool].size;
+		}
+		/* make sure we are not larger than what is allowed by the HW */
+#define PIO_MAX_BLOCKS 1024
+		if (dd->sc_sizes[i].size > PIO_MAX_BLOCKS)
+			dd->sc_sizes[i].size = PIO_MAX_BLOCKS;
+
+		/* calculate our total usage */
+		used_blocks += dd->sc_sizes[i].size * dd->sc_sizes[i].count;
+	}
+	extra = total_blocks - used_blocks;
+	if (extra != 0)
+		dd_dev_info(dd, "unused send context blocks: %d\n", extra);
+
+	return total_contexts;
+}
+
+int init_send_contexts(struct hfi1_devdata *dd)
+{
+	u16 base;
+	int ret, i, j, context;
+
+	ret = init_credit_return(dd);
+	if (ret)
+		return ret;
+
+	dd->hw_to_sw = kmalloc_array(TXE_NUM_CONTEXTS, sizeof(u8),
+					GFP_KERNEL);
+	dd->send_contexts = kcalloc(dd->num_send_contexts,
+					sizeof(struct send_context_info),
+					GFP_KERNEL);
+	if (!dd->send_contexts || !dd->hw_to_sw) {
+		dd_dev_err(dd, "Unable to allocate send context arrays\n");
+		kfree(dd->hw_to_sw);
+		kfree(dd->send_contexts);
+		free_credit_return(dd);
+		return -ENOMEM;
+	}
+
+	/* hardware context map starts with invalid send context indices */
+	for (i = 0; i < TXE_NUM_CONTEXTS; i++)
+		dd->hw_to_sw[i] = INVALID_SCI;
+
+	/*
+	 * All send contexts have their credit sizes.  Allocate credits
+	 * for each context one after another from the global space.
+	 */
+	context = 0;
+	base = 1;
+	for (i = 0; i < SC_MAX; i++) {
+		struct sc_config_sizes *scs = &dd->sc_sizes[i];
+
+		for (j = 0; j < scs->count; j++) {
+			struct send_context_info *sci =
+						&dd->send_contexts[context];
+			sci->type = i;
+			sci->base = base;
+			sci->credits = scs->size;
+
+			context++;
+			base += scs->size;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Allocate a software index and hardware context of the given type.
+ *
+ * Must be called with dd->sc_lock held.
+ */
+static int sc_hw_alloc(struct hfi1_devdata *dd, int type, u32 *sw_index,
+		       u32 *hw_context)
+{
+	struct send_context_info *sci;
+	u32 index;
+	u32 context;
+
+	for (index = 0, sci = &dd->send_contexts[0];
+			index < dd->num_send_contexts; index++, sci++) {
+		if (sci->type == type && sci->allocated == 0) {
+			sci->allocated = 1;
+			/* use a 1:1 mapping, but make them non-equal */
+			context = dd->chip_send_contexts - index - 1;
+			dd->hw_to_sw[context] = index;
+			*sw_index = index;
+			*hw_context = context;
+			return 0; /* success */
+		}
+	}
+	dd_dev_err(dd, "Unable to locate a free type %d send context\n", type);
+	return -ENOSPC;
+}
+
+/*
+ * Free the send context given by its software index.
+ *
+ * Must be called with dd->sc_lock held.
+ */
+static void sc_hw_free(struct hfi1_devdata *dd, u32 sw_index, u32 hw_context)
+{
+	struct send_context_info *sci;
+
+	sci = &dd->send_contexts[sw_index];
+	if (!sci->allocated) {
+		dd_dev_err(dd, "%s: sw_index %u not allocated? hw_context %u\n",
+			__func__, sw_index, hw_context);
+	}
+	sci->allocated = 0;
+	dd->hw_to_sw[hw_context] = INVALID_SCI;
+}
+
+/* return the base context of a context in a group */
+static inline u32 group_context(u32 context, u32 group)
+{
+	return (context >> group) << group;
+}
+
+/* return the size of a group */
+static inline u32 group_size(u32 group)
+{
+	return 1 << group;
+}
+
+/*
+ * Obtain the credit return addresses, kernel virtual and physical, for the
+ * given sc.
+ *
+ * To understand this routine:
+ * o va and pa are arrays of struct credit_return.  One for each physical
+ *   send context, per NUMA.
+ * o Each send context always looks in its relative location in a struct
+ *   credit_return for its credit return.
+ * o Each send context in a group must have its return address CSR programmed
+ *   with the same value.  Use the address of the first send context in the
+ *   group.
+ */
+static void cr_group_addresses(struct send_context *sc, dma_addr_t *pa)
+{
+	u32 gc = group_context(sc->hw_context, sc->group);
+	u32 index = sc->hw_context & 0x7;
+
+	sc->hw_free = &sc->dd->cr_base[sc->node].va[gc].cr[index];
+	*pa = (unsigned long)
+	       &((struct credit_return *)sc->dd->cr_base[sc->node].pa)[gc];
+}
+
+/*
+ * Work queue function triggered in error interrupt routine for
+ * kernel contexts.
+ */
+static void sc_halted(struct work_struct *work)
+{
+	struct send_context *sc;
+
+	sc = container_of(work, struct send_context, halt_work);
+	sc_restart(sc);
+}
+
+/*
+ * Calculate PIO block threshold for this send context using the given MTU.
+ * Trigger a return when one MTU plus optional header of credits remain.
+ *
+ * Parameter mtu is in bytes.
+ * Parameter hdrqentsize is in DWORDs.
+ *
+ * Return value is what to write into the CSR: trigger return when
+ * unreturned credits pass this count.
+ */
+u32 sc_mtu_to_threshold(struct send_context *sc, u32 mtu, u32 hdrqentsize)
+{
+	u32 release_credits;
+	u32 threshold;
+
+	/* add in the header size, then divide by the PIO block size */
+	mtu += hdrqentsize << 2;
+	release_credits = DIV_ROUND_UP(mtu, PIO_BLOCK_SIZE);
+
+	/* check against this context's credits */
+	if (sc->credits <= release_credits)
+		threshold = 1;
+	else
+		threshold = sc->credits - release_credits;
+
+	return threshold;
+}
+
+/*
+ * Calculate credit threshold in terms of percent of the allocated credits.
+ * Trigger when unreturned credits equal or exceed the percentage of the whole.
+ *
+ * Return value is what to write into the CSR: trigger return when
+ * unreturned credits pass this count.
+ */
+static u32 sc_percent_to_threshold(struct send_context *sc, u32 percent)
+{
+	return (sc->credits * percent) / 100;
+}
+
+/*
+ * Set the credit return threshold.
+ */
+void sc_set_cr_threshold(struct send_context *sc, u32 new_threshold)
+{
+	unsigned long flags;
+	u32 old_threshold;
+	int force_return = 0;
+
+	spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
+
+	old_threshold = (sc->credit_ctrl >>
+				SC(CREDIT_CTRL_THRESHOLD_SHIFT))
+			 & SC(CREDIT_CTRL_THRESHOLD_MASK);
+
+	if (new_threshold != old_threshold) {
+		sc->credit_ctrl =
+			(sc->credit_ctrl
+				& ~SC(CREDIT_CTRL_THRESHOLD_SMASK))
+			| ((new_threshold
+				& SC(CREDIT_CTRL_THRESHOLD_MASK))
+			   << SC(CREDIT_CTRL_THRESHOLD_SHIFT));
+		write_kctxt_csr(sc->dd, sc->hw_context,
+			SC(CREDIT_CTRL), sc->credit_ctrl);
+
+		/* force a credit return on change to avoid a possible stall */
+		force_return = 1;
+	}
+
+	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
+
+	if (force_return)
+		sc_return_credits(sc);
+}
+
+/*
+ * set_pio_integrity
+ *
+ * Set the CHECK_ENABLE register for the send context 'sc'.
+ */
+void set_pio_integrity(struct send_context *sc)
+{
+	struct hfi1_devdata *dd = sc->dd;
+	u64 reg = 0;
+	u32 hw_context = sc->hw_context;
+	int type = sc->type;
+
+	/*
+	 * No integrity checks if HFI1_CAP_NO_INTEGRITY is set, or if
+	 * we're snooping.
+	 */
+	if (likely(!HFI1_CAP_IS_KSET(NO_INTEGRITY)) &&
+	    dd->hfi1_snoop.mode_flag != HFI1_PORT_SNOOP_MODE)
+		reg = hfi1_pkt_default_send_ctxt_mask(dd, type);
+
+	write_kctxt_csr(dd, hw_context, SC(CHECK_ENABLE), reg);
+}
+
+/*
+ * Allocate a NUMA relative send context structure of the given type along
+ * with a HW context.
+ */
+struct send_context *sc_alloc(struct hfi1_devdata *dd, int type,
+			      uint hdrqentsize, int numa)
+{
+	struct send_context_info *sci;
+	struct send_context *sc;
+	dma_addr_t pa;
+	unsigned long flags;
+	u64 reg;
+	u32 thresh;
+	u32 sw_index;
+	u32 hw_context;
+	int ret;
+	u8 opval, opmask;
+
+	/* do not allocate while frozen */
+	if (dd->flags & HFI1_FROZEN)
+		return NULL;
+
+	sc = kzalloc_node(sizeof(struct send_context), GFP_KERNEL, numa);
+	if (!sc) {
+		dd_dev_err(dd, "Cannot allocate send context structure\n");
+		return NULL;
+	}
+
+	spin_lock_irqsave(&dd->sc_lock, flags);
+	ret = sc_hw_alloc(dd, type, &sw_index, &hw_context);
+	if (ret) {
+		spin_unlock_irqrestore(&dd->sc_lock, flags);
+		kfree(sc);
+		return NULL;
+	}
+
+	sci = &dd->send_contexts[sw_index];
+	sci->sc = sc;
+
+	sc->dd = dd;
+	sc->node = numa;
+	sc->type = type;
+	spin_lock_init(&sc->alloc_lock);
+	spin_lock_init(&sc->release_lock);
+	spin_lock_init(&sc->credit_ctrl_lock);
+	INIT_LIST_HEAD(&sc->piowait);
+	INIT_WORK(&sc->halt_work, sc_halted);
+	atomic_set(&sc->buffers_allocated, 0);
+	init_waitqueue_head(&sc->halt_wait);
+
+	/* grouping is always single context for now */
+	sc->group = 0;
+
+	sc->sw_index = sw_index;
+	sc->hw_context = hw_context;
+	cr_group_addresses(sc, &pa);
+	sc->credits = sci->credits;
+
+/* PIO Send Memory Address details */
+#define PIO_ADDR_CONTEXT_MASK 0xfful
+#define PIO_ADDR_CONTEXT_SHIFT 16
+	sc->base_addr = dd->piobase + ((hw_context & PIO_ADDR_CONTEXT_MASK)
+					<< PIO_ADDR_CONTEXT_SHIFT);
+
+	/* set base and credits */
+	reg = ((sci->credits & SC(CTRL_CTXT_DEPTH_MASK))
+					<< SC(CTRL_CTXT_DEPTH_SHIFT))
+		| ((sci->base & SC(CTRL_CTXT_BASE_MASK))
+					<< SC(CTRL_CTXT_BASE_SHIFT));
+	write_kctxt_csr(dd, hw_context, SC(CTRL), reg);
+
+	set_pio_integrity(sc);
+
+	/* unmask all errors */
+	write_kctxt_csr(dd, hw_context, SC(ERR_MASK), (u64)-1);
+
+	/* set the default partition key */
+	write_kctxt_csr(dd, hw_context, SC(CHECK_PARTITION_KEY),
+		(DEFAULT_PKEY &
+			SC(CHECK_PARTITION_KEY_VALUE_MASK))
+		    << SC(CHECK_PARTITION_KEY_VALUE_SHIFT));
+
+	/* per context type checks */
+	if (type == SC_USER) {
+		opval = USER_OPCODE_CHECK_VAL;
+		opmask = USER_OPCODE_CHECK_MASK;
+	} else {
+		opval = OPCODE_CHECK_VAL_DISABLED;
+		opmask = OPCODE_CHECK_MASK_DISABLED;
+	}
+
+	/* set the send context check opcode mask and value */
+	write_kctxt_csr(dd, hw_context, SC(CHECK_OPCODE),
+		((u64)opmask << SC(CHECK_OPCODE_MASK_SHIFT)) |
+		((u64)opval << SC(CHECK_OPCODE_VALUE_SHIFT)));
+
+	/* set up credit return */
+	reg = pa & SC(CREDIT_RETURN_ADDR_ADDRESS_SMASK);
+	write_kctxt_csr(dd, hw_context, SC(CREDIT_RETURN_ADDR), reg);
+
+	/*
+	 * Calculate the initial credit return threshold.
+	 *
+	 * For Ack contexts, set a threshold for half the credits.
+	 * For User contexts use the given percentage.  This has been
+	 * sanitized on driver start-up.
+	 * For Kernel contexts, use the default MTU plus a header.
+	 */
+	if (type == SC_ACK) {
+		thresh = sc_percent_to_threshold(sc, 50);
+	} else if (type == SC_USER) {
+		thresh = sc_percent_to_threshold(sc,
+				user_credit_return_threshold);
+	} else { /* kernel */
+		thresh = sc_mtu_to_threshold(sc, hfi1_max_mtu, hdrqentsize);
+	}
+	reg = thresh << SC(CREDIT_CTRL_THRESHOLD_SHIFT);
+	/* add in early return */
+	if (type == SC_USER && HFI1_CAP_IS_USET(EARLY_CREDIT_RETURN))
+		reg |= SC(CREDIT_CTRL_EARLY_RETURN_SMASK);
+	else if (HFI1_CAP_IS_KSET(EARLY_CREDIT_RETURN)) /* kernel, ack */
+		reg |= SC(CREDIT_CTRL_EARLY_RETURN_SMASK);
+
+	/* set up write-through credit_ctrl */
+	sc->credit_ctrl = reg;
+	write_kctxt_csr(dd, hw_context, SC(CREDIT_CTRL), reg);
+
+	spin_unlock_irqrestore(&dd->sc_lock, flags);
+
+	/*
+	 * Allocate shadow ring to track outstanding PIO buffers _after_
+	 * unlocking.  We don't know the size until the lock is held and
+	 * we can't allocate while the lock is held.  No one is using
+	 * the context yet, so allocate it now.
+	 *
+	 * User contexts do not get a shadow ring.
+	 */
+	if (type != SC_USER) {
+		/*
+		 * Size the shadow ring 1 larger than the number of credits
+		 * so head == tail can mean empty.
+		 */
+		sc->sr_size = sci->credits + 1;
+		sc->sr = kzalloc_node(sizeof(union pio_shadow_ring) *
+				sc->sr_size, GFP_KERNEL, numa);
+		if (!sc->sr) {
+			dd_dev_err(dd,
+				"Cannot allocate send context shadow ring structure\n");
+			sc_free(sc);
+			return NULL;
+		}
+	}
+
+	dd_dev_info(dd,
+		"Send context %u(%u) %s group %u credits %u credit_ctrl 0x%llx threshold %u\n",
+		sw_index,
+		hw_context,
+		sc_type_name(type),
+		sc->group,
+		sc->credits,
+		sc->credit_ctrl,
+		thresh);
+
+	return sc;
+}
+
+/* free a per-NUMA send context structure */
+void sc_free(struct send_context *sc)
+{
+	struct hfi1_devdata *dd;
+	unsigned long flags;
+	u32 sw_index;
+	u32 hw_context;
+
+	if (!sc)
+		return;
+
+	sc->flags |= SCF_IN_FREE;	/* ensure no restarts */
+	dd = sc->dd;
+	if (!list_empty(&sc->piowait))
+		dd_dev_err(dd, "piowait list not empty!\n");
+	sw_index = sc->sw_index;
+	hw_context = sc->hw_context;
+	sc_disable(sc);	/* make sure the HW is disabled */
+	flush_work(&sc->halt_work);
+
+	spin_lock_irqsave(&dd->sc_lock, flags);
+	dd->send_contexts[sw_index].sc = NULL;
+
+	/* clear/disable all registers set in sc_alloc */
+	write_kctxt_csr(dd, hw_context, SC(CTRL), 0);
+	write_kctxt_csr(dd, hw_context, SC(CHECK_ENABLE), 0);
+	write_kctxt_csr(dd, hw_context, SC(ERR_MASK), 0);
+	write_kctxt_csr(dd, hw_context, SC(CHECK_PARTITION_KEY), 0);
+	write_kctxt_csr(dd, hw_context, SC(CHECK_OPCODE), 0);
+	write_kctxt_csr(dd, hw_context, SC(CREDIT_RETURN_ADDR), 0);
+	write_kctxt_csr(dd, hw_context, SC(CREDIT_CTRL), 0);
+
+	/* release the index and context for re-use */
+	sc_hw_free(dd, sw_index, hw_context);
+	spin_unlock_irqrestore(&dd->sc_lock, flags);
+
+	kfree(sc->sr);
+	kfree(sc);
+}
+
+/* disable the context */
+void sc_disable(struct send_context *sc)
+{
+	u64 reg;
+	unsigned long flags;
+	struct pio_buf *pbuf;
+
+	if (!sc)
+		return;
+
+	/* do all steps, even if already disabled */
+	spin_lock_irqsave(&sc->alloc_lock, flags);
+	reg = read_kctxt_csr(sc->dd, sc->hw_context, SC(CTRL));
+	reg &= ~SC(CTRL_CTXT_ENABLE_SMASK);
+	sc->flags &= ~SCF_ENABLED;
+	sc_wait_for_packet_egress(sc, 1);
+	write_kctxt_csr(sc->dd, sc->hw_context, SC(CTRL), reg);
+	spin_unlock_irqrestore(&sc->alloc_lock, flags);
+
+	/*
+	 * Flush any waiters.  Once the context is disabled,
+	 * credit return interrupts are stopped (although there
+	 * could be one in-process when the context is disabled).
+	 * Wait one microsecond for any lingering interrupts, then
+	 * proceed with the flush.
+	 */
+	udelay(1);
+	spin_lock_irqsave(&sc->release_lock, flags);
+	if (sc->sr) {	/* this context has a shadow ring */
+		while (sc->sr_tail != sc->sr_head) {
+			pbuf = &sc->sr[sc->sr_tail].pbuf;
+			if (pbuf->cb)
+				(*pbuf->cb)(pbuf->arg, PRC_SC_DISABLE);
+			sc->sr_tail++;
+			if (sc->sr_tail >= sc->sr_size)
+				sc->sr_tail = 0;
+		}
+	}
+	spin_unlock_irqrestore(&sc->release_lock, flags);
+}
+
+/* return SendEgressCtxtStatus.PacketOccupancy */
+#define packet_occupancy(r) \
+	(((r) & SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_PACKET_OCCUPANCY_SMASK)\
+	>> SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_PACKET_OCCUPANCY_SHIFT)
+
+/* is egress halted on the context? */
+#define egress_halted(r) \
+	((r) & SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_HALT_STATUS_SMASK)
+
+/* wait for packet egress, optionally pause for credit return  */
+static void sc_wait_for_packet_egress(struct send_context *sc, int pause)
+{
+	struct hfi1_devdata *dd = sc->dd;
+	u64 reg;
+	u32 loop = 0;
+
+	while (1) {
+		reg = read_csr(dd, sc->hw_context * 8 +
+			       SEND_EGRESS_CTXT_STATUS);
+		/* done if egress is stopped */
+		if (egress_halted(reg))
+			break;
+		reg = packet_occupancy(reg);
+		if (reg == 0)
+			break;
+		if (loop > 100) {
+			dd_dev_err(dd,
+				"%s: context %u(%u) timeout waiting for packets to egress, remaining count %u\n",
+				__func__, sc->sw_index,
+				sc->hw_context, (u32)reg);
+			break;
+		}
+		loop++;
+		udelay(1);
+	}
+
+	if (pause)
+		/* Add additional delay to ensure chip returns all credits */
+		pause_for_credit_return(dd);
+}
+
+void sc_wait(struct hfi1_devdata *dd)
+{
+	int i;
+
+	for (i = 0; i < dd->num_send_contexts; i++) {
+		struct send_context *sc = dd->send_contexts[i].sc;
+
+		if (!sc)
+			continue;
+		sc_wait_for_packet_egress(sc, 0);
+	}
+}
+
+/*
+ * Restart a context after it has been halted due to error.
+ *
+ * If the first step fails - wait for the halt to be asserted, return early.
+ * Otherwise complain about timeouts but keep going.
+ *
+ * It is expected that allocations (enabled flag bit) have been shut off
+ * already (only applies to kernel contexts).
+ */
+int sc_restart(struct send_context *sc)
+{
+	struct hfi1_devdata *dd = sc->dd;
+	u64 reg;
+	u32 loop;
+	int count;
+
+	/* bounce off if not halted, or being free'd */
+	if (!(sc->flags & SCF_HALTED) || (sc->flags & SCF_IN_FREE))
+		return -EINVAL;
+
+	dd_dev_info(dd, "restarting send context %u(%u)\n", sc->sw_index,
+		sc->hw_context);
+
+	/*
+	 * Step 1: Wait for the context to actually halt.
+	 *
+	 * The error interrupt is asynchronous to actually setting halt
+	 * on the context.
+	 */
+	loop = 0;
+	while (1) {
+		reg = read_kctxt_csr(dd, sc->hw_context, SC(STATUS));
+		if (reg & SC(STATUS_CTXT_HALTED_SMASK))
+			break;
+		if (loop > 100) {
+			dd_dev_err(dd, "%s: context %u(%u) not halting, skipping\n",
+				__func__, sc->sw_index, sc->hw_context);
+			return -ETIME;
+		}
+		loop++;
+		udelay(1);
+	}
+
+	/*
+	 * Step 2: Ensure no users are still trying to write to PIO.
+	 *
+	 * For kernel contexts, we have already turned off buffer allocation.
+	 * Now wait for the buffer count to go to zero.
+	 *
+	 * For user contexts, the user handling code has cut off write access
+	 * to the context's PIO pages before calling this routine and will
+	 * restore write access after this routine returns.
+	 */
+	if (sc->type != SC_USER) {
+		/* kernel context */
+		loop = 0;
+		while (1) {
+			count = atomic_read(&sc->buffers_allocated);
+			if (count == 0)
+				break;
+			if (loop > 100) {
+				dd_dev_err(dd,
+					"%s: context %u(%u) timeout waiting for PIO buffers to zero, remaining %d\n",
+					__func__, sc->sw_index,
+					sc->hw_context, count);
+			}
+			loop++;
+			udelay(1);
+		}
+	}
+
+	/*
+	 * Step 3: Wait for all packets to egress.
+	 * This is done while disabling the send context
+	 *
+	 * Step 4: Disable the context
+	 *
+	 * This is a superset of the halt.  After the disable, the
+	 * errors can be cleared.
+	 */
+	sc_disable(sc);
+
+	/*
+	 * Step 5: Enable the context
+	 *
+	 * This enable will clear the halted flag and per-send context
+	 * error flags.
+	 */
+	return sc_enable(sc);
+}
+
+/*
+ * PIO freeze processing.  To be called after the TXE block is fully frozen.
+ * Go through all frozen send contexts and disable them.  The contexts are
+ * already stopped by the freeze.
+ */
+void pio_freeze(struct hfi1_devdata *dd)
+{
+	struct send_context *sc;
+	int i;
+
+	for (i = 0; i < dd->num_send_contexts; i++) {
+		sc = dd->send_contexts[i].sc;
+		/*
+		 * Don't disable unallocated, unfrozen, or user send contexts.
+		 * User send contexts will be disabled when the process
+		 * calls into the driver to reset its context.
+		 */
+		if (!sc || !(sc->flags & SCF_FROZEN) || sc->type == SC_USER)
+			continue;
+
+		/* only need to disable, the context is already stopped */
+		sc_disable(sc);
+	}
+}
+
+/*
+ * Unfreeze PIO for kernel send contexts.  The precondition for calling this
+ * is that all PIO send contexts have been disabled and the SPC freeze has
+ * been cleared.  Now perform the last step and re-enable each kernel context.
+ * User (PSM) processing will occur when PSM calls into the kernel to
+ * acknowledge the freeze.
+ */
+void pio_kernel_unfreeze(struct hfi1_devdata *dd)
+{
+	struct send_context *sc;
+	int i;
+
+	for (i = 0; i < dd->num_send_contexts; i++) {
+		sc = dd->send_contexts[i].sc;
+		if (!sc || !(sc->flags & SCF_FROZEN) || sc->type == SC_USER)
+			continue;
+
+		sc_enable(sc);	/* will clear the sc frozen flag */
+	}
+}
+
+/*
+ * Wait for the SendPioInitCtxt.PioInitInProgress bit to clear.
+ * Returns:
+ *	-ETIMEDOUT - if we wait too long
+ *	-EIO	   - if there was an error
+ */
+static int pio_init_wait_progress(struct hfi1_devdata *dd)
+{
+	u64 reg;
+	int count = 0;
+
+	while (1) {
+		reg = read_csr(dd, SEND_PIO_INIT_CTXT);
+		if (!(reg & SEND_PIO_INIT_CTXT_PIO_INIT_IN_PROGRESS_SMASK))
+			break;
+		mdelay(20);
+		if (count++ > 10)
+			return -ETIMEDOUT;
+	}
+
+	return reg & SEND_PIO_INIT_CTXT_PIO_INIT_ERR_SMASK ? -EIO : 0;
+}
+
+/*
+ * Reset all of the send contexts to their power-on state.  Used
+ * only during manual init - no lock against sc_enable needed.
+ */
+void pio_reset_all(struct hfi1_devdata *dd)
+{
+	int ret;
+
+	/* make sure the init engine is not busy */
+	ret = pio_init_wait_progress(dd);
+	if (ret == -ETIMEDOUT) {
+		dd_dev_err(dd,
+			"PIO send context init is stuck, not initializing PIO blocks\n");
+		return;
+	}
+
+	if (ret == -EIO) {
+		/* clear the error */
+		write_csr(dd, SEND_PIO_ERR_CLEAR,
+			SEND_PIO_ERR_CLEAR_PIO_INIT_SM_IN_ERR_SMASK);
+	}
+
+	/* reset init all */
+	write_csr(dd, SEND_PIO_INIT_CTXT,
+			SEND_PIO_INIT_CTXT_PIO_ALL_CTXT_INIT_SMASK);
+	udelay(2);
+	ret = pio_init_wait_progress(dd);
+	if (ret < 0) {
+		dd_dev_err(dd,
+			"PIO send context init %s while initializing all PIO blocks\n",
+			ret == -ETIMEDOUT ? "is stuck" : "had an error");
+	}
+}
+
+/* enable the context */
+int sc_enable(struct send_context *sc)
+{
+	u64 sc_ctrl, reg, pio;
+	struct hfi1_devdata *dd;
+	unsigned long flags;
+	int ret = 0;
+
+	if (!sc)
+		return -EINVAL;
+	dd = sc->dd;
+
+	/*
+	 * Obtain the allocator lock to guard against any allocation
+	 * attempts (which should not happen prior to context being
+	 * enabled). On the release/disable side we don't need to
+	 * worry about locking since the releaser will not do anything
+	 * if the context accounting values have not changed.
+	 */
+	spin_lock_irqsave(&sc->alloc_lock, flags);
+	sc_ctrl = read_kctxt_csr(dd, sc->hw_context, SC(CTRL));
+	if ((sc_ctrl & SC(CTRL_CTXT_ENABLE_SMASK)))
+		goto unlock; /* already enabled */
+
+	/* IMPORTANT: only clear free and fill if transitioning 0 -> 1 */
+
+	*sc->hw_free = 0;
+	sc->free = 0;
+	sc->alloc_free = 0;
+	sc->fill = 0;
+	sc->sr_head = 0;
+	sc->sr_tail = 0;
+	sc->flags = 0;
+	atomic_set(&sc->buffers_allocated, 0);
+
+	/*
+	 * Clear all per-context errors.  Some of these will be set when
+	 * we are re-enabling after a context halt.  Now that the context
+	 * is disabled, the halt will not clear until after the PIO init
+	 * engine runs below.
+	 */
+	reg = read_kctxt_csr(dd, sc->hw_context, SC(ERR_STATUS));
+	if (reg)
+		write_kctxt_csr(dd, sc->hw_context, SC(ERR_CLEAR),
+			reg);
+
+	/*
+	 * The HW PIO initialization engine can handle only one init
+	 * request at a time. Serialize access to each device's engine.
+	 */
+	spin_lock(&dd->sc_init_lock);
+	/*
+	 * Since access to this code block is serialized and
+	 * each access waits for the initialization to complete
+	 * before releasing the lock, the PIO initialization engine
+	 * should not be in use, so we don't have to wait for the
+	 * InProgress bit to go down.
+	 */
+	pio = ((sc->hw_context & SEND_PIO_INIT_CTXT_PIO_CTXT_NUM_MASK) <<
+	       SEND_PIO_INIT_CTXT_PIO_CTXT_NUM_SHIFT) |
+		SEND_PIO_INIT_CTXT_PIO_SINGLE_CTXT_INIT_SMASK;
+	write_csr(dd, SEND_PIO_INIT_CTXT, pio);
+	/*
+	 * Wait until the engine is done.  Give the chip the required time
+	 * so, hopefully, we read the register just once.
+	 */
+	udelay(2);
+	ret = pio_init_wait_progress(dd);
+	spin_unlock(&dd->sc_init_lock);
+	if (ret) {
+		dd_dev_err(dd,
+			   "sctxt%u(%u): Context not enabled due to init failure %d\n",
+			   sc->sw_index, sc->hw_context, ret);
+		goto unlock;
+	}
+
+	/*
+	 * All is well. Enable the context.
+	 */
+	sc_ctrl |= SC(CTRL_CTXT_ENABLE_SMASK);
+	write_kctxt_csr(dd, sc->hw_context, SC(CTRL), sc_ctrl);
+	/*
+	 * Read SendCtxtCtrl to force the write out and prevent a timing
+	 * hazard where a PIO write may reach the context before the enable.
+	 */
+	read_kctxt_csr(dd, sc->hw_context, SC(CTRL));
+	sc->flags |= SCF_ENABLED;
+
+unlock:
+	spin_unlock_irqrestore(&sc->alloc_lock, flags);
+
+	return ret;
+}
+
+/* force a credit return on the context */
+void sc_return_credits(struct send_context *sc)
+{
+	if (!sc)
+		return;
+
+	/* a 0->1 transition schedules a credit return */
+	write_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE),
+		SC(CREDIT_FORCE_FORCE_RETURN_SMASK));
+	/*
+	 * Ensure that the write is flushed and the credit return is
+	 * scheduled. We care more about the 0 -> 1 transition.
+	 */
+	read_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE));
+	/* set back to 0 for next time */
+	write_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE), 0);
+}
+
+/* allow all in-flight packets to drain on the context */
+void sc_flush(struct send_context *sc)
+{
+	if (!sc)
+		return;
+
+	sc_wait_for_packet_egress(sc, 1);
+}
+
+/* drop all packets on the context, no waiting until they are sent */
+void sc_drop(struct send_context *sc)
+{
+	if (!sc)
+		return;
+
+	dd_dev_info(sc->dd, "%s: context %u(%u) - not implemented\n",
+			__func__, sc->sw_index, sc->hw_context);
+}
+
+/*
+ * Start the software reaction to a context halt or SPC freeze:
+ *	- mark the context as halted or frozen
+ *	- stop buffer allocations
+ *
+ * Called from the error interrupt.  Other work is deferred until
+ * out of the interrupt.
+ */
+void sc_stop(struct send_context *sc, int flag)
+{
+	unsigned long flags;
+
+	/* mark the context */
+	sc->flags |= flag;
+
+	/* stop buffer allocations */
+	spin_lock_irqsave(&sc->alloc_lock, flags);
+	sc->flags &= ~SCF_ENABLED;
+	spin_unlock_irqrestore(&sc->alloc_lock, flags);
+	wake_up(&sc->halt_wait);
+}
+
+#define BLOCK_DWORDS (PIO_BLOCK_SIZE/sizeof(u32))
+#define dwords_to_blocks(x) DIV_ROUND_UP(x, BLOCK_DWORDS)
+
+/*
+ * The send context buffer "allocator".
+ *
+ * @sc: the PIO send context we are allocating from
+ * @len: length of whole packet - including PBC - in dwords
+ * @cb: optional callback to call when the buffer is finished sending
+ * @arg: argument for cb
+ *
+ * Return a pointer to a PIO buffer if successful, NULL if not enough room.
+ */
+struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len,
+				pio_release_cb cb, void *arg)
+{
+	struct pio_buf *pbuf = NULL;
+	unsigned long flags;
+	unsigned long avail;
+	unsigned long blocks = dwords_to_blocks(dw_len);
+	unsigned long start_fill;
+	int trycount = 0;
+	u32 head, next;
+
+	spin_lock_irqsave(&sc->alloc_lock, flags);
+	if (!(sc->flags & SCF_ENABLED)) {
+		spin_unlock_irqrestore(&sc->alloc_lock, flags);
+		goto done;
+	}
+
+retry:
+	avail = (unsigned long)sc->credits - (sc->fill - sc->alloc_free);
+	if (blocks > avail) {
+		/* not enough room */
+		if (unlikely(trycount))	{ /* already tried to get more room */
+			spin_unlock_irqrestore(&sc->alloc_lock, flags);
+			goto done;
+		}
+		/* copy from receiver cache line and recalculate */
+		sc->alloc_free = ACCESS_ONCE(sc->free);
+		avail =
+			(unsigned long)sc->credits -
+			(sc->fill - sc->alloc_free);
+		if (blocks > avail) {
+			/* still no room, actively update */
+			spin_unlock_irqrestore(&sc->alloc_lock, flags);
+			sc_release_update(sc);
+			spin_lock_irqsave(&sc->alloc_lock, flags);
+			sc->alloc_free = ACCESS_ONCE(sc->free);
+			trycount++;
+			goto retry;
+		}
+	}
+
+	/* there is enough room */
+
+	atomic_inc(&sc->buffers_allocated);
+
+	/* read this once */
+	head = sc->sr_head;
+
+	/* "allocate" the buffer */
+	start_fill = sc->fill;
+	sc->fill += blocks;
+
+	/*
+	 * Fill the parts that the releaser looks at before moving the head.
+	 * The only necessary piece is the sent_at field.  The credits
+	 * we have just allocated cannot have been returned yet, so the
+	 * cb and arg will not be looked at for a "while".  Put them
+	 * on this side of the memory barrier anyway.
+	 */
+	pbuf = &sc->sr[head].pbuf;
+	pbuf->sent_at = sc->fill;
+	pbuf->cb = cb;
+	pbuf->arg = arg;
+	pbuf->sc = sc;	/* could be filled in at sc->sr init time */
+	/* make sure this is in memory before updating the head */
+
+	/* calculate next head index, do not store */
+	next = head + 1;
+	if (next >= sc->sr_size)
+		next = 0;
+	/* update the head - must be last! - the releaser can look at fields
+	   in pbuf once we move the head */
+	smp_wmb();
+	sc->sr_head = next;
+	spin_unlock_irqrestore(&sc->alloc_lock, flags);
+
+	/* finish filling in the buffer outside the lock */
+	pbuf->start = sc->base_addr + ((start_fill % sc->credits)
+							* PIO_BLOCK_SIZE);
+	pbuf->size = sc->credits * PIO_BLOCK_SIZE;
+	pbuf->end = sc->base_addr + pbuf->size;
+	pbuf->block_count = blocks;
+	pbuf->qw_written = 0;
+	pbuf->carry_bytes = 0;
+	pbuf->carry.val64 = 0;
+done:
+	return pbuf;
+}
+
+/*
+ * There are at least two entities that can turn on credit return
+ * interrupts and they can overlap.  Avoid problems by implementing
+ * a count scheme that is enforced by a lock.  The lock is needed because
+ * the count and CSR write must be paired.
+ */
+
+/*
+ * Start credit return interrupts.  This is managed by a count.  If already
+ * on, just increment the count.
+ */
+void sc_add_credit_return_intr(struct send_context *sc)
+{
+	unsigned long flags;
+
+	/* lock must surround both the count change and the CSR update */
+	spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
+	if (sc->credit_intr_count == 0) {
+		sc->credit_ctrl |= SC(CREDIT_CTRL_CREDIT_INTR_SMASK);
+		write_kctxt_csr(sc->dd, sc->hw_context,
+			SC(CREDIT_CTRL), sc->credit_ctrl);
+	}
+	sc->credit_intr_count++;
+	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
+}
+
+/*
+ * Stop credit return interrupts.  This is managed by a count.  Decrement the
+ * count, if the last user, then turn the credit interrupts off.
+ */
+void sc_del_credit_return_intr(struct send_context *sc)
+{
+	unsigned long flags;
+
+	BUG_ON(sc->credit_intr_count == 0);
+
+	/* lock must surround both the count change and the CSR update */
+	spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
+	sc->credit_intr_count--;
+	if (sc->credit_intr_count == 0) {
+		sc->credit_ctrl &= ~SC(CREDIT_CTRL_CREDIT_INTR_SMASK);
+		write_kctxt_csr(sc->dd, sc->hw_context,
+			SC(CREDIT_CTRL), sc->credit_ctrl);
+	}
+	spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
+}
+
+/*
+ * The caller must be careful when calling this.  All needint calls
+ * must be paired with !needint.
+ */
+void hfi1_sc_wantpiobuf_intr(struct send_context *sc, u32 needint)
+{
+	if (needint)
+		sc_add_credit_return_intr(sc);
+	else
+		sc_del_credit_return_intr(sc);
+	trace_hfi1_wantpiointr(sc, needint, sc->credit_ctrl);
+	if (needint) {
+		mmiowb();
+		sc_return_credits(sc);
+	}
+}
+
+/**
+ * sc_piobufavail - callback when a PIO buffer is available
+ * @sc: the send context
+ *
+ * This is called from the interrupt handler when a PIO buffer is
+ * available after hfi1_verbs_send() returned an error that no buffers were
+ * available. Disable the interrupt if there are no more QPs waiting.
+ */
+static void sc_piobufavail(struct send_context *sc)
+{
+	struct hfi1_devdata *dd = sc->dd;
+	struct hfi1_ibdev *dev = &dd->verbs_dev;
+	struct list_head *list;
+	struct hfi1_qp *qps[PIO_WAIT_BATCH_SIZE];
+	struct hfi1_qp *qp;
+	unsigned long flags;
+	unsigned i, n = 0;
+
+	if (dd->send_contexts[sc->sw_index].type != SC_KERNEL)
+		return;
+	list = &sc->piowait;
+	/*
+	 * Note: checking that the piowait list is empty and clearing
+	 * the buffer available interrupt needs to be atomic or we
+	 * could end up with QPs on the wait list with the interrupt
+	 * disabled.
+	 */
+	spin_lock_irqsave(&dev->pending_lock, flags);
+	while (!list_empty(list)) {
+		struct iowait *wait;
+
+		if (n == ARRAY_SIZE(qps))
+			goto full;
+		wait = list_first_entry(list, struct iowait, list);
+		qp = container_of(wait, struct hfi1_qp, s_iowait);
+		list_del_init(&qp->s_iowait.list);
+		/* refcount held until actual wake up */
+		qps[n++] = qp;
+	}
+	/*
+	 * Counting: only call wantpiobuf_intr() if there were waiters and they
+	 * are now all gone.
+	 */
+	if (n)
+		hfi1_sc_wantpiobuf_intr(sc, 0);
+full:
+	spin_unlock_irqrestore(&dev->pending_lock, flags);
+
+	for (i = 0; i < n; i++)
+		hfi1_qp_wakeup(qps[i], HFI1_S_WAIT_PIO);
+}
+
+/* translate a send credit update to a bit code of reasons */
+static inline int fill_code(u64 hw_free)
+{
+	int code = 0;
+
+	if (hw_free & CR_STATUS_SMASK)
+		code |= PRC_STATUS_ERR;
+	if (hw_free & CR_CREDIT_RETURN_DUE_TO_PBC_SMASK)
+		code |= PRC_PBC;
+	if (hw_free & CR_CREDIT_RETURN_DUE_TO_THRESHOLD_SMASK)
+		code |= PRC_THRESHOLD;
+	if (hw_free & CR_CREDIT_RETURN_DUE_TO_ERR_SMASK)
+		code |= PRC_FILL_ERR;
+	if (hw_free & CR_CREDIT_RETURN_DUE_TO_FORCE_SMASK)
+		code |= PRC_SC_DISABLE;
+	return code;
+}
+
+/* use the jiffies compare to get the wrap right */
+#define sent_before(a, b) time_before(a, b)	/* a < b */
+
+/*
+ * The send context buffer "releaser".
+ */
+void sc_release_update(struct send_context *sc)
+{
+	struct pio_buf *pbuf;
+	u64 hw_free;
+	u32 head, tail;
+	unsigned long old_free;
+	unsigned long extra;
+	unsigned long flags;
+	int code;
+
+	if (!sc)
+		return;
+
+	spin_lock_irqsave(&sc->release_lock, flags);
+	/* update free */
+	hw_free = le64_to_cpu(*sc->hw_free);		/* volatile read */
+	old_free = sc->free;
+	extra = (((hw_free & CR_COUNTER_SMASK) >> CR_COUNTER_SHIFT)
+			- (old_free & CR_COUNTER_MASK))
+				& CR_COUNTER_MASK;
+	sc->free = old_free + extra;
+	trace_hfi1_piofree(sc, extra);
+
+	/* call sent buffer callbacks */
+	code = -1;				/* code not yet set */
+	head = ACCESS_ONCE(sc->sr_head);	/* snapshot the head */
+	tail = sc->sr_tail;
+	while (head != tail) {
+		pbuf = &sc->sr[tail].pbuf;
+
+		if (sent_before(sc->free, pbuf->sent_at)) {
+			/* not sent yet */
+			break;
+		}
+		if (pbuf->cb) {
+			if (code < 0) /* fill in code on first user */
+				code = fill_code(hw_free);
+			(*pbuf->cb)(pbuf->arg, code);
+		}
+
+		tail++;
+		if (tail >= sc->sr_size)
+			tail = 0;
+	}
+	/* update tail, in case we moved it */
+	sc->sr_tail = tail;
+	spin_unlock_irqrestore(&sc->release_lock, flags);
+	sc_piobufavail(sc);
+}
+
+/*
+ * Send context group releaser.  Argument is the send context that caused
+ * the interrupt.  Called from the send context interrupt handler.
+ *
+ * Call release on all contexts in the group.
+ *
+ * This routine takes the sc_lock without an irqsave because it is only
+ * called from an interrupt handler.  Adjust if that changes.
+ */
+void sc_group_release_update(struct hfi1_devdata *dd, u32 hw_context)
+{
+	struct send_context *sc;
+	u32 sw_index;
+	u32 gc, gc_end;
+
+	spin_lock(&dd->sc_lock);
+	sw_index = dd->hw_to_sw[hw_context];
+	if (unlikely(sw_index >= dd->num_send_contexts)) {
+		dd_dev_err(dd, "%s: invalid hw (%u) to sw (%u) mapping\n",
+			__func__, hw_context, sw_index);
+		goto done;
+	}
+	sc = dd->send_contexts[sw_index].sc;
+	if (unlikely(!sc))
+		goto done;
+
+	gc = group_context(hw_context, sc->group);
+	gc_end = gc + group_size(sc->group);
+	for (; gc < gc_end; gc++) {
+		sw_index = dd->hw_to_sw[gc];
+		if (unlikely(sw_index >= dd->num_send_contexts)) {
+			dd_dev_err(dd,
+				"%s: invalid hw (%u) to sw (%u) mapping\n",
+				__func__, hw_context, sw_index);
+			continue;
+		}
+		sc_release_update(dd->send_contexts[sw_index].sc);
+	}
+done:
+	spin_unlock(&dd->sc_lock);
+}
+
+int init_pervl_scs(struct hfi1_devdata *dd)
+{
+	int i;
+	u64 mask, all_vl_mask = (u64) 0x80ff; /* VLs 0-7, 15 */
+	u32 ctxt;
+
+	dd->vld[15].sc = sc_alloc(dd, SC_KERNEL,
+				  dd->rcd[0]->rcvhdrqentsize, dd->node);
+	if (!dd->vld[15].sc)
+		goto nomem;
+	hfi1_init_ctxt(dd->vld[15].sc);
+	dd->vld[15].mtu = enum_to_mtu(OPA_MTU_2048);
+	for (i = 0; i < num_vls; i++) {
+		/*
+		 * Since this function does not deal with a specific
+		 * receive context but we need the RcvHdrQ entry size,
+		 * use the size from rcd[0]. It is guaranteed to be
+		 * valid at this point and will remain the same for all
+		 * receive contexts.
+		 */
+		dd->vld[i].sc = sc_alloc(dd, SC_KERNEL,
+					 dd->rcd[0]->rcvhdrqentsize, dd->node);
+		if (!dd->vld[i].sc)
+			goto nomem;
+
+		hfi1_init_ctxt(dd->vld[i].sc);
+
+		/* non VL15 start with the max MTU */
+		dd->vld[i].mtu = hfi1_max_mtu;
+	}
+	sc_enable(dd->vld[15].sc);
+	ctxt = dd->vld[15].sc->hw_context;
+	mask = all_vl_mask & ~(1LL << 15);
+	write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask);
+	dd_dev_info(dd,
+		    "Using send context %u(%u) for VL15\n",
+		    dd->vld[15].sc->sw_index, ctxt);
+	for (i = 0; i < num_vls; i++) {
+		sc_enable(dd->vld[i].sc);
+		ctxt = dd->vld[i].sc->hw_context;
+		mask = all_vl_mask & ~(1LL << i);
+		write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask);
+	}
+	return 0;
+nomem:
+	sc_free(dd->vld[15].sc);
+	for (i = 0; i < num_vls; i++)
+		sc_free(dd->vld[i].sc);
+	return -ENOMEM;
+}
+
+int init_credit_return(struct hfi1_devdata *dd)
+{
+	int ret;
+	int num_numa;
+	int i;
+
+	num_numa = num_online_nodes();
+	/* enforce the expectation that the numas are compact */
+	for (i = 0; i < num_numa; i++) {
+		if (!node_online(i)) {
+			dd_dev_err(dd, "NUMA nodes are not compact\n");
+			ret = -EINVAL;
+			goto done;
+		}
+	}
+
+	dd->cr_base = kcalloc(
+		num_numa,
+		sizeof(struct credit_return_base),
+		GFP_KERNEL);
+	if (!dd->cr_base) {
+		dd_dev_err(dd, "Unable to allocate credit return base\n");
+		ret = -ENOMEM;
+		goto done;
+	}
+	for (i = 0; i < num_numa; i++) {
+		int bytes = TXE_NUM_CONTEXTS * sizeof(struct credit_return);
+
+		set_dev_node(&dd->pcidev->dev, i);
+		dd->cr_base[i].va = dma_zalloc_coherent(
+					&dd->pcidev->dev,
+					bytes,
+					&dd->cr_base[i].pa,
+					GFP_KERNEL);
+		if (dd->cr_base[i].va == NULL) {
+			set_dev_node(&dd->pcidev->dev, dd->node);
+			dd_dev_err(dd,
+				"Unable to allocate credit return DMA range for NUMA %d\n",
+				i);
+			ret = -ENOMEM;
+			goto done;
+		}
+	}
+	set_dev_node(&dd->pcidev->dev, dd->node);
+
+	ret = 0;
+done:
+	return ret;
+}
+
+void free_credit_return(struct hfi1_devdata *dd)
+{
+	int num_numa;
+	int i;
+
+	if (!dd->cr_base)
+		return;
+
+	num_numa = num_online_nodes();
+	for (i = 0; i < num_numa; i++) {
+		if (dd->cr_base[i].va) {
+			dma_free_coherent(&dd->pcidev->dev,
+				TXE_NUM_CONTEXTS
+					* sizeof(struct credit_return),
+				dd->cr_base[i].va,
+				dd->cr_base[i].pa);
+		}
+	}
+	kfree(dd->cr_base);
+	dd->cr_base = NULL;
+}
diff --git a/drivers/infiniband/hw/hfi1/pio.h b/drivers/infiniband/hw/hfi1/pio.h
new file mode 100644
index 0000000..0bb885c
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/pio.h
@@ -0,0 +1,224 @@
+#ifndef _PIO_H
+#define _PIO_H
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  - Neither the name of Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+
+/* send context types */
+#define SC_KERNEL 0
+#define SC_ACK    1
+#define SC_USER   2
+#define SC_MAX    3
+
+/* invalid send context index */
+#define INVALID_SCI 0xff
+
+/* PIO buffer release callback function */
+typedef void (*pio_release_cb)(void *arg, int code);
+
+/* PIO release codes - in bits, as there could more than one that apply */
+#define PRC_OK		0	/* no known error */
+#define PRC_STATUS_ERR	0x01	/* credit return due to status error */
+#define PRC_PBC		0x02	/* credit return due to PBC */
+#define PRC_THRESHOLD	0x04	/* credit return due to threshold */
+#define PRC_FILL_ERR	0x08	/* credit return due fill error */
+#define PRC_FORCE	0x10	/* credit return due credit force */
+#define PRC_SC_DISABLE	0x20	/* clean-up after a context disable */
+
+/* byte helper */
+union mix {
+	u64 val64;
+	u32 val32[2];
+	u8  val8[8];
+};
+
+/* an allocated PIO buffer */
+struct pio_buf {
+	struct send_context *sc;/* back pointer to owning send context */
+	pio_release_cb cb;	/* called when the buffer is released */
+	void *arg;		/* argument for cb */
+	void __iomem *start;	/* buffer start address */
+	void __iomem *end;	/* context end address */
+	unsigned long size;	/* context size, in bytes */
+	unsigned long sent_at;	/* buffer is sent when <= free */
+	u32 block_count;	/* size of buffer, in blocks */
+	u32 qw_written;		/* QW written so far */
+	u32 carry_bytes;	/* number of valid bytes in carry */
+	union mix carry;	/* pending unwritten bytes */
+};
+
+/* cache line aligned pio buffer array */
+union pio_shadow_ring {
+	struct pio_buf pbuf;
+	u64 unused[16];		/* cache line spacer */
+} ____cacheline_aligned;
+
+/* per-NUMA send context */
+struct send_context {
+	/* read-only after init */
+	struct hfi1_devdata *dd;		/* device */
+	void __iomem *base_addr;	/* start of PIO memory */
+	union pio_shadow_ring *sr;	/* shadow ring */
+	volatile __le64 *hw_free;	/* HW free counter */
+	struct work_struct halt_work;	/* halted context work queue entry */
+	unsigned long flags;		/* flags */
+	int node;			/* context home node */
+	int type;			/* context type */
+	u32 sw_index;			/* software index number */
+	u32 hw_context;			/* hardware context number */
+	u32 credits;			/* number of blocks in context */
+	u32 sr_size;			/* size of the shadow ring */
+	u32 group;			/* credit return group */
+	/* allocator fields */
+	spinlock_t alloc_lock ____cacheline_aligned_in_smp;
+	unsigned long fill;		/* official alloc count */
+	unsigned long alloc_free;	/* copy of free (less cache thrash) */
+	u32 sr_head;			/* shadow ring head */
+	/* releaser fields */
+	spinlock_t release_lock ____cacheline_aligned_in_smp;
+	unsigned long free;		/* official free count */
+	u32 sr_tail;			/* shadow ring tail */
+	/* list for PIO waiters */
+	struct list_head piowait  ____cacheline_aligned_in_smp;
+	spinlock_t credit_ctrl_lock ____cacheline_aligned_in_smp;
+	u64 credit_ctrl;		/* cache for credit control */
+	u32 credit_intr_count;		/* count of credit intr users */
+	atomic_t buffers_allocated;	/* count of buffers allocated */
+	wait_queue_head_t halt_wait;    /* wait until kernel sees interrupt */
+};
+
+/* send context flags */
+#define SCF_ENABLED 0x01
+#define SCF_IN_FREE 0x02
+#define SCF_HALTED  0x04
+#define SCF_FROZEN  0x08
+
+struct send_context_info {
+	struct send_context *sc;	/* allocated working context */
+	u16 allocated;			/* has this been allocated? */
+	u16 type;			/* context type */
+	u16 base;			/* base in PIO array */
+	u16 credits;			/* size in PIO array */
+};
+
+/* DMA credit return, index is always (context & 0x7) */
+struct credit_return {
+	volatile __le64 cr[8];
+};
+
+/* NUMA indexed credit return array */
+struct credit_return_base {
+	struct credit_return *va;
+	dma_addr_t pa;
+};
+
+/* send context configuration sizes (one per type) */
+struct sc_config_sizes {
+	short int size;
+	short int count;
+};
+
+/* send context functions */
+int init_credit_return(struct hfi1_devdata *dd);
+void free_credit_return(struct hfi1_devdata *dd);
+int init_sc_pools_and_sizes(struct hfi1_devdata *dd);
+int init_send_contexts(struct hfi1_devdata *dd);
+int init_credit_return(struct hfi1_devdata *dd);
+int init_pervl_scs(struct hfi1_devdata *dd);
+struct send_context *sc_alloc(struct hfi1_devdata *dd, int type,
+			      uint hdrqentsize, int numa);
+void sc_free(struct send_context *sc);
+int sc_enable(struct send_context *sc);
+void sc_disable(struct send_context *sc);
+int sc_restart(struct send_context *sc);
+void sc_return_credits(struct send_context *sc);
+void sc_flush(struct send_context *sc);
+void sc_drop(struct send_context *sc);
+void sc_stop(struct send_context *sc, int bit);
+struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len,
+			pio_release_cb cb, void *arg);
+void sc_release_update(struct send_context *sc);
+void sc_return_credits(struct send_context *sc);
+void sc_group_release_update(struct hfi1_devdata *dd, u32 hw_context);
+void sc_add_credit_return_intr(struct send_context *sc);
+void sc_del_credit_return_intr(struct send_context *sc);
+void sc_set_cr_threshold(struct send_context *sc, u32 new_threshold);
+u32 sc_mtu_to_threshold(struct send_context *sc, u32 mtu, u32 hdrqentsize);
+void hfi1_sc_wantpiobuf_intr(struct send_context *sc, u32 needint);
+void sc_wait(struct hfi1_devdata *dd);
+void set_pio_integrity(struct send_context *sc);
+
+/* support functions */
+void pio_reset_all(struct hfi1_devdata *dd);
+void pio_freeze(struct hfi1_devdata *dd);
+void pio_kernel_unfreeze(struct hfi1_devdata *dd);
+
+/* global PIO send control operations */
+#define PSC_GLOBAL_ENABLE 0
+#define PSC_GLOBAL_DISABLE 1
+#define PSC_GLOBAL_VLARB_ENABLE 2
+#define PSC_GLOBAL_VLARB_DISABLE 3
+#define PSC_CM_RESET 4
+#define PSC_DATA_VL_ENABLE 5
+#define PSC_DATA_VL_DISABLE 6
+
+void __cm_reset(struct hfi1_devdata *dd, u64 sendctrl);
+void pio_send_control(struct hfi1_devdata *dd, int op);
+
+
+/* PIO copy routines */
+void pio_copy(struct hfi1_devdata *dd, struct pio_buf *pbuf, u64 pbc,
+	      const void *from, size_t count);
+void seg_pio_copy_start(struct pio_buf *pbuf, u64 pbc,
+					const void *from, size_t nbytes);
+void seg_pio_copy_mid(struct pio_buf *pbuf, const void *from, size_t nbytes);
+void seg_pio_copy_end(struct pio_buf *pbuf);
+
+#endif /* _PIO_H */
diff --git a/drivers/infiniband/hw/hfi1/pio_copy.c b/drivers/infiniband/hw/hfi1/pio_copy.c
new file mode 100644
index 0000000..baa09d3
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/pio_copy.c
@@ -0,0 +1,867 @@
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  - Neither the name of Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "hfi.h"
+
+/* additive distance between non-SOP and SOP space */
+#define SOP_DISTANCE (TXE_PIO_SIZE / 2)
+#define PIO_BLOCK_MASK (PIO_BLOCK_SIZE-1)
+/* number of QUADWORDs in a block */
+#define PIO_BLOCK_QWS (PIO_BLOCK_SIZE/sizeof(u64))
+
+/**
+ * pio_copy - copy data block to MMIO space
+ * @pbuf: a number of blocks allocated within a PIO send context
+ * @pbc: PBC to send
+ * @from: source, must be 8 byte aligned
+ * @count: number of DWORD (32-bit) quantities to copy from source
+ *
+ * Copy data from source to PIO Send Buffer memory, 8 bytes at a time.
+ * Must always write full BLOCK_SIZE bytes blocks.  The first block must
+ * be written to the corresponding SOP=1 address.
+ *
+ * Known:
+ * o pbuf->start always starts on a block boundary
+ * o pbuf can wrap only at a block boundary
+ */
+void pio_copy(struct hfi1_devdata *dd, struct pio_buf *pbuf, u64 pbc,
+	      const void *from, size_t count)
+{
+	void __iomem *dest = pbuf->start + SOP_DISTANCE;
+	void __iomem *send = dest + PIO_BLOCK_SIZE;
+	void __iomem *dend;			/* 8-byte data end */
+
+	/* write the PBC */
+	writeq(pbc, dest);
+	dest += sizeof(u64);
+
+	/* calculate where the QWORD data ends - in SOP=1 space */
+	dend = dest + ((count>>1) * sizeof(u64));
+
+	if (dend < send) {
+		/* all QWORD data is within the SOP block, does *not*
+		   reach the end of the SOP block */
+
+		while (dest < dend) {
+			writeq(*(u64 *)from, dest);
+			from += sizeof(u64);
+			dest += sizeof(u64);
+		}
+		/*
+		 * No boundary checks are needed here:
+		 * 0. We're not on the SOP block boundary
+		 * 1. The possible DWORD dangle will still be within
+		 *    the SOP block
+		 * 2. We cannot wrap except on a block boundary.
+		 */
+	} else {
+		/* QWORD data extends _to_ or beyond the SOP block */
+
+		/* write 8-byte SOP chunk data */
+		while (dest < send) {
+			writeq(*(u64 *)from, dest);
+			from += sizeof(u64);
+			dest += sizeof(u64);
+		}
+		/* drop out of the SOP range */
+		dest -= SOP_DISTANCE;
+		dend -= SOP_DISTANCE;
+
+		/*
+		 * If the wrap comes before or matches the data end,
+		 * copy until until the wrap, then wrap.
+		 *
+		 * If the data ends at the end of the SOP above and
+		 * the buffer wraps, then pbuf->end == dend == dest
+		 * and nothing will get written, but we will wrap in
+		 * case there is a dangling DWORD.
+		 */
+		if (pbuf->end <= dend) {
+			while (dest < pbuf->end) {
+				writeq(*(u64 *)from, dest);
+				from += sizeof(u64);
+				dest += sizeof(u64);
+			}
+
+			dest -= pbuf->size;
+			dend -= pbuf->size;
+		}
+
+		/* write 8-byte non-SOP, non-wrap chunk data */
+		while (dest < dend) {
+			writeq(*(u64 *)from, dest);
+			from += sizeof(u64);
+			dest += sizeof(u64);
+		}
+	}
+	/* at this point we have wrapped if we are going to wrap */
+
+	/* write dangling u32, if any */
+	if (count & 1) {
+		union mix val;
+
+		val.val64 = 0;
+		val.val32[0] = *(u32 *)from;
+		writeq(val.val64, dest);
+		dest += sizeof(u64);
+	}
+	/* fill in rest of block, no need to check pbuf->end
+	   as we only wrap on a block boundary */
+	while (((unsigned long)dest & PIO_BLOCK_MASK) != 0) {
+		writeq(0, dest);
+		dest += sizeof(u64);
+	}
+
+	/* finished with this buffer */
+	atomic_dec(&pbuf->sc->buffers_allocated);
+}
+
+/* USE_SHIFTS is faster in user-space tests on a Xeon X5570 @ 2.93GHz */
+#define USE_SHIFTS 1
+#ifdef USE_SHIFTS
+/*
+ * Handle carry bytes using shifts and masks.
+ *
+ * NOTE: the value the unused portion of carry is expected to always be zero.
+ */
+
+/*
+ * "zero" shift - bit shift used to zero out upper bytes.  Input is
+ * the count of LSB bytes to preserve.
+ */
+#define zshift(x) (8 * (8-(x)))
+
+/*
+ * "merge" shift - bit shift used to merge with carry bytes.  Input is
+ * the LSB byte count to move beyond.
+ */
+#define mshift(x) (8 * (x))
+
+/*
+ * Read nbytes bytes from "from" and return them in the LSB bytes
+ * of pbuf->carry.  Other bytes are zeroed.  Any previous value
+ * pbuf->carry is lost.
+ *
+ * NOTES:
+ * o do not read from from if nbytes is zero
+ * o from may _not_ be u64 aligned
+ * o nbytes must not span a QW boundary
+ */
+static inline void read_low_bytes(struct pio_buf *pbuf, const void *from,
+							unsigned int nbytes)
+{
+	unsigned long off;
+
+	if (nbytes == 0) {
+		pbuf->carry.val64 = 0;
+	} else {
+		/* align our pointer */
+		off = (unsigned long)from & 0x7;
+		BUG_ON(nbytes+off > 8);
+		from = (void *)((unsigned long)from & ~0x7l);
+		pbuf->carry.val64 = ((*(u64 *)from)
+				<< zshift(nbytes + off))/* zero upper bytes */
+				>> zshift(nbytes);	/* place at bottom */
+	}
+	pbuf->carry_bytes = nbytes;
+}
+
+/*
+ * Read nbytes bytes from "from" and put them at the next significant bytes
+ * of pbuf->carry.  Unused bytes are zeroed.  It is expected that the extra
+ * read does not overfill carry.
+ *
+ * NOTES:
+ * o from may _not_ be u64 aligned
+ * o nbytes may span a QW boundary
+ */
+static inline void read_extra_bytes(struct pio_buf *pbuf,
+					const void *from, unsigned int nbytes)
+{
+	unsigned long off = (unsigned long)from & 0x7;
+	unsigned int room, xbytes;
+
+	BUG_ON(pbuf->carry_bytes + nbytes > 8);
+
+	/* align our pointer */
+	from = (void *)((unsigned long)from & ~0x7l);
+
+	/* check count first - don't read anything if count is zero */
+	while (nbytes) {
+		/* find the number of bytes in this u64 */
+		room = 8 - off;	/* this u64 has room for this many bytes */
+		xbytes = nbytes > room ? room : nbytes;
+
+		/*
+		 * shift down to zero lower bytes, shift up to zero upper
+		 * bytes, shift back down to move into place
+		 */
+		pbuf->carry.val64 |= (((*(u64 *)from)
+					>> mshift(off))
+					<< zshift(xbytes))
+					>> zshift(xbytes+pbuf->carry_bytes);
+		off = 0;
+		pbuf->carry_bytes += xbytes;
+		nbytes -= xbytes;
+		from += sizeof(u64);
+	}
+}
+
+/*
+ * Zero extra bytes from the end of pbuf->carry.
+ *
+ * NOTES:
+ * o zbytes <= old_bytes
+ */
+static inline void zero_extra_bytes(struct pio_buf *pbuf, unsigned int zbytes)
+{
+	unsigned int remaining;
+
+	BUG_ON(pbuf->carry_bytes < zbytes);
+
+	if (zbytes == 0)	/* nothing to do */
+		return;
+
+	remaining = pbuf->carry_bytes - zbytes;	/* remaining bytes */
+
+	/* NOTE: zshift only guaranteed to work if remaining != 0 */
+	if (remaining)
+		pbuf->carry.val64 = (pbuf->carry.val64 << zshift(remaining))
+					>> zshift(remaining);
+	else
+		pbuf->carry.val64 = 0;
+	pbuf->carry_bytes = remaining;
+}
+
+/*
+ * Write a quad word using parts of pbuf->carry and the next 8 bytes of src.
+ * Put the unused part of the next 8 bytes of src into the LSB bytes of
+ * pbuf->carry with the upper bytes zeroed..
+ *
+ * NOTES:
+ * o result must keep unused bytes zeroed
+ * o src must be u64 aligned
+ */
+static inline void merge_write8(
+	struct pio_buf *pbuf,
+	void __iomem *dest,
+	const void *src)
+{
+	u64 new, temp;
+
+	new = *(u64 *)src;
+	temp = pbuf->carry.val64 | (new << mshift(pbuf->carry_bytes));
+	writeq(temp, dest);
+	pbuf->carry.val64 = new >> zshift(pbuf->carry_bytes);
+}
+
+/*
+ * Write a quad word using all bytes of carry.
+ */
+static inline void carry8_write8(union mix carry, void __iomem *dest)
+{
+	writeq(carry.val64, dest);
+}
+
+/*
+ * Write a quad word using all the valid bytes of carry.  If carry
+ * has zero valid bytes, nothing is written.
+ * Returns 0 on nothing written, non-zero on quad word written.
+ */
+static inline int carry_write8(struct pio_buf *pbuf, void __iomem *dest)
+{
+	if (pbuf->carry_bytes) {
+		/* unused bytes are always kept zeroed, so just write */
+		writeq(pbuf->carry.val64, dest);
+		return 1;
+	}
+
+	return 0;
+}
+
+#else /* USE_SHIFTS */
+/*
+ * Handle carry bytes using byte copies.
+ *
+ * NOTE: the value the unused portion of carry is left uninitialized.
+ */
+
+/*
+ * Jump copy - no-loop copy for < 8 bytes.
+ */
+static inline void jcopy(u8 *dest, const u8 *src, u32 n)
+{
+	switch (n) {
+	case 7:
+		*dest++ = *src++;
+	case 6:
+		*dest++ = *src++;
+	case 5:
+		*dest++ = *src++;
+	case 4:
+		*dest++ = *src++;
+	case 3:
+		*dest++ = *src++;
+	case 2:
+		*dest++ = *src++;
+	case 1:
+		*dest++ = *src++;
+	}
+}
+
+/*
+ * Read nbytes from "from" and and place them in the low bytes
+ * of pbuf->carry.  Other bytes are left as-is.  Any previous
+ * value in pbuf->carry is lost.
+ *
+ * NOTES:
+ * o do not read from from if nbytes is zero
+ * o from may _not_ be u64 aligned.
+ */
+static inline void read_low_bytes(struct pio_buf *pbuf, const void *from,
+							unsigned int nbytes)
+{
+	BUG_ON(nbytes >= 8);
+
+	jcopy(&pbuf->carry.val8[0], from, nbytes);
+	pbuf->carry_bytes = nbytes;
+}
+
+/*
+ * Read nbytes bytes from "from" and put them at the end of pbuf->carry.
+ * It is expected that the extra read does not overfill carry.
+ *
+ * NOTES:
+ * o from may _not_ be u64 aligned
+ * o nbytes may span a QW boundary
+ */
+static inline void read_extra_bytes(struct pio_buf *pbuf,
+					const void *from, unsigned int nbytes)
+{
+	BUG_ON(pbuf->carry_bytes + nbytes > 8);
+	jcopy(&pbuf->carry.val8[pbuf->carry_bytes], from, nbytes);
+	pbuf->carry_bytes += nbytes;
+}
+
+/*
+ * Zero extra bytes from the end of pbuf->carry.
+ *
+ * We do not care about the value of unused bytes in carry, so just
+ * reduce the byte count.
+ *
+ * NOTES:
+ * o zbytes <= old_bytes
+ */
+static inline void zero_extra_bytes(struct pio_buf *pbuf, unsigned int zbytes)
+{
+	BUG_ON(pbuf->carry_bytes < zbytes);
+	pbuf->carry_bytes -= zbytes;
+}
+
+/*
+ * Write a quad word using parts of pbuf->carry and the next 8 bytes of src.
+ * Put the unused part of the next 8 bytes of src into the low bytes of
+ * pbuf->carry.
+ */
+static inline void merge_write8(
+	struct pio_buf *pbuf,
+	void *dest,
+	const void *src)
+{
+	u32 remainder = 8 - pbuf->carry_bytes;
+
+	jcopy(&pbuf->carry.val8[pbuf->carry_bytes], src, remainder);
+	writeq(pbuf->carry.val64, dest);
+	jcopy(&pbuf->carry.val8[0], src+remainder, pbuf->carry_bytes);
+}
+
+/*
+ * Write a quad word using all bytes of carry.
+ */
+static inline void carry8_write8(union mix carry, void *dest)
+{
+	writeq(carry.val64, dest);
+}
+
+/*
+ * Write a quad word using all the valid bytes of carry.  If carry
+ * has zero valid bytes, nothing is written.
+ * Returns 0 on nothing written, non-zero on quad word written.
+ */
+static inline int carry_write8(struct pio_buf *pbuf, void *dest)
+{
+	if (pbuf->carry_bytes) {
+		u64 zero = 0;
+
+		jcopy(&pbuf->carry.val8[pbuf->carry_bytes], (u8 *)&zero,
+						8 - pbuf->carry_bytes);
+		writeq(pbuf->carry.val64, dest);
+		return 1;
+	}
+
+	return 0;
+}
+#endif /* USE_SHIFTS */
+
+/*
+ * Segmented PIO Copy - start
+ *
+ * Start a PIO copy.
+ *
+ * @pbuf: destination buffer
+ * @pbc: the PBC for the PIO buffer
+ * @from: data source, QWORD aligned
+ * @nbytes: bytes to copy
+ */
+void seg_pio_copy_start(struct pio_buf *pbuf, u64 pbc,
+				const void *from, size_t nbytes)
+{
+	void __iomem *dest = pbuf->start + SOP_DISTANCE;
+	void __iomem *send = dest + PIO_BLOCK_SIZE;
+	void __iomem *dend;			/* 8-byte data end */
+
+	writeq(pbc, dest);
+	dest += sizeof(u64);
+
+	/* calculate where the QWORD data ends - in SOP=1 space */
+	dend = dest + ((nbytes>>3) * sizeof(u64));
+
+	if (dend < send) {
+		/* all QWORD data is within the SOP block, does *not*
+		   reach the end of the SOP block */
+
+		while (dest < dend) {
+			writeq(*(u64 *)from, dest);
+			from += sizeof(u64);
+			dest += sizeof(u64);
+		}
+		/*
+		 * No boundary checks are needed here:
+		 * 0. We're not on the SOP block boundary
+		 * 1. The possible DWORD dangle will still be within
+		 *    the SOP block
+		 * 2. We cannot wrap except on a block boundary.
+		 */
+	} else {
+		/* QWORD data extends _to_ or beyond the SOP block */
+
+		/* write 8-byte SOP chunk data */
+		while (dest < send) {
+			writeq(*(u64 *)from, dest);
+			from += sizeof(u64);
+			dest += sizeof(u64);
+		}
+		/* drop out of the SOP range */
+		dest -= SOP_DISTANCE;
+		dend -= SOP_DISTANCE;
+
+		/*
+		 * If the wrap comes before or matches the data end,
+		 * copy until until the wrap, then wrap.
+		 *
+		 * If the data ends at the end of the SOP above and
+		 * the buffer wraps, then pbuf->end == dend == dest
+		 * and nothing will get written, but we will wrap in
+		 * case there is a dangling DWORD.
+		 */
+		if (pbuf->end <= dend) {
+			while (dest < pbuf->end) {
+				writeq(*(u64 *)from, dest);
+				from += sizeof(u64);
+				dest += sizeof(u64);
+			}
+
+			dest -= pbuf->size;
+			dend -= pbuf->size;
+		}
+
+		/* write 8-byte non-SOP, non-wrap chunk data */
+		while (dest < dend) {
+			writeq(*(u64 *)from, dest);
+			from += sizeof(u64);
+			dest += sizeof(u64);
+		}
+	}
+	/* at this point we have wrapped if we are going to wrap */
+
+	/* ...but it doesn't matter as we're done writing */
+
+	/* save dangling bytes, if any */
+	read_low_bytes(pbuf, from, nbytes & 0x7);
+
+	pbuf->qw_written = 1 /*PBC*/ + (nbytes >> 3);
+}
+
+/*
+ * Mid copy helper, "mixed case" - source is 64-bit aligned but carry
+ * bytes are non-zero.
+ *
+ * Whole u64s must be written to the chip, so bytes must be manually merged.
+ *
+ * @pbuf: destination buffer
+ * @from: data source, is QWORD aligned.
+ * @nbytes: bytes to copy
+ *
+ * Must handle nbytes < 8.
+ */
+static void mid_copy_mix(struct pio_buf *pbuf, const void *from, size_t nbytes)
+{
+	void __iomem *dest = pbuf->start + (pbuf->qw_written * sizeof(u64));
+	void __iomem *dend;			/* 8-byte data end */
+	unsigned long qw_to_write = (pbuf->carry_bytes + nbytes) >> 3;
+	unsigned long bytes_left = (pbuf->carry_bytes + nbytes) & 0x7;
+
+	/* calculate 8-byte data end */
+	dend = dest + (qw_to_write * sizeof(u64));
+
+	if (pbuf->qw_written < PIO_BLOCK_QWS) {
+		/*
+		 * Still within SOP block.  We don't need to check for
+		 * wrap because we are still in the first block and
+		 * can only wrap on block boundaries.
+		 */
+		void __iomem *send;		/* SOP end */
+		void __iomem *xend;
+
+		/* calculate the end of data or end of block, whichever
+		   comes first */
+		send = pbuf->start + PIO_BLOCK_SIZE;
+		xend = send < dend ? send : dend;
+
+		/* shift up to SOP=1 space */
+		dest += SOP_DISTANCE;
+		xend += SOP_DISTANCE;
+
+		/* write 8-byte chunk data */
+		while (dest < xend) {
+			merge_write8(pbuf, dest, from);
+			from += sizeof(u64);
+			dest += sizeof(u64);
+		}
+
+		/* shift down to SOP=0 space */
+		dest -= SOP_DISTANCE;
+	}
+	/*
+	 * At this point dest could be (either, both, or neither):
+	 * - at dend
+	 * - at the wrap
+	 */
+
+	/*
+	 * If the wrap comes before or matches the data end,
+	 * copy until until the wrap, then wrap.
+	 *
+	 * If dest is at the wrap, we will fall into the if,
+	 * not do the loop, when wrap.
+	 *
+	 * If the data ends at the end of the SOP above and
+	 * the buffer wraps, then pbuf->end == dend == dest
+	 * and nothing will get written.
+	 */
+	if (pbuf->end <= dend) {
+		while (dest < pbuf->end) {
+			merge_write8(pbuf, dest, from);
+			from += sizeof(u64);
+			dest += sizeof(u64);
+		}
+
+		dest -= pbuf->size;
+		dend -= pbuf->size;
+	}
+
+	/* write 8-byte non-SOP, non-wrap chunk data */
+	while (dest < dend) {
+		merge_write8(pbuf, dest, from);
+		from += sizeof(u64);
+		dest += sizeof(u64);
+	}
+
+	/* adjust carry */
+	if (pbuf->carry_bytes < bytes_left) {
+		/* need to read more */
+		read_extra_bytes(pbuf, from, bytes_left - pbuf->carry_bytes);
+	} else {
+		/* remove invalid bytes */
+		zero_extra_bytes(pbuf, pbuf->carry_bytes - bytes_left);
+	}
+
+	pbuf->qw_written += qw_to_write;
+}
+
+/*
+ * Mid copy helper, "straight case" - source pointer is 64-bit aligned
+ * with no carry bytes.
+ *
+ * @pbuf: destination buffer
+ * @from: data source, is QWORD aligned
+ * @nbytes: bytes to copy
+ *
+ * Must handle nbytes < 8.
+ */
+static void mid_copy_straight(struct pio_buf *pbuf,
+						const void *from, size_t nbytes)
+{
+	void __iomem *dest = pbuf->start + (pbuf->qw_written * sizeof(u64));
+	void __iomem *dend;			/* 8-byte data end */
+
+	/* calculate 8-byte data end */
+	dend = dest + ((nbytes>>3) * sizeof(u64));
+
+	if (pbuf->qw_written < PIO_BLOCK_QWS) {
+		/*
+		 * Still within SOP block.  We don't need to check for
+		 * wrap because we are still in the first block and
+		 * can only wrap on block boundaries.
+		 */
+		void __iomem *send;		/* SOP end */
+		void __iomem *xend;
+
+		/* calculate the end of data or end of block, whichever
+		   comes first */
+		send = pbuf->start + PIO_BLOCK_SIZE;
+		xend = send < dend ? send : dend;
+
+		/* shift up to SOP=1 space */
+		dest += SOP_DISTANCE;
+		xend += SOP_DISTANCE;
+
+		/* write 8-byte chunk data */
+		while (dest < xend) {
+			writeq(*(u64 *)from, dest);
+			from += sizeof(u64);
+			dest += sizeof(u64);
+		}
+
+		/* shift down to SOP=0 space */
+		dest -= SOP_DISTANCE;
+	}
+	/*
+	 * At this point dest could be (either, both, or neither):
+	 * - at dend
+	 * - at the wrap
+	 */
+
+	/*
+	 * If the wrap comes before or matches the data end,
+	 * copy until until the wrap, then wrap.
+	 *
+	 * If dest is at the wrap, we will fall into the if,
+	 * not do the loop, when wrap.
+	 *
+	 * If the data ends at the end of the SOP above and
+	 * the buffer wraps, then pbuf->end == dend == dest
+	 * and nothing will get written.
+	 */
+	if (pbuf->end <= dend) {
+		while (dest < pbuf->end) {
+			writeq(*(u64 *)from, dest);
+			from += sizeof(u64);
+			dest += sizeof(u64);
+		}
+
+		dest -= pbuf->size;
+		dend -= pbuf->size;
+	}
+
+	/* write 8-byte non-SOP, non-wrap chunk data */
+	while (dest < dend) {
+		writeq(*(u64 *)from, dest);
+		from += sizeof(u64);
+		dest += sizeof(u64);
+	}
+
+	/* we know carry_bytes was zero on entry to this routine */
+	read_low_bytes(pbuf, from, nbytes & 0x7);
+
+	pbuf->qw_written += nbytes>>3;
+}
+
+/*
+ * Segmented PIO Copy - middle
+ *
+ * Must handle any aligned tail and any aligned source with any byte count.
+ *
+ * @pbuf: a number of blocks allocated within a PIO send context
+ * @from: data source
+ * @nbytes: number of bytes to copy
+ */
+void seg_pio_copy_mid(struct pio_buf *pbuf, const void *from, size_t nbytes)
+{
+	unsigned long from_align = (unsigned long)from & 0x7;
+
+	if (pbuf->carry_bytes + nbytes < 8) {
+		/* not enough bytes to fill a QW */
+		read_extra_bytes(pbuf, from, nbytes);
+		return;
+	}
+
+	if (from_align) {
+		/* misaligned source pointer - align it */
+		unsigned long to_align;
+
+		/* bytes to read to align "from" */
+		to_align = 8 - from_align;
+
+		/*
+		 * In the advance-to-alignment logic below, we do not need
+		 * to check if we are using more than nbytes.  This is because
+		 * if we are here, we already know that carry+nbytes will
+		 * fill at least one QW.
+		 */
+		if (pbuf->carry_bytes + to_align < 8) {
+			/* not enough align bytes to fill a QW */
+			read_extra_bytes(pbuf, from, to_align);
+			from += to_align;
+			nbytes -= to_align;
+		} else {
+			/* bytes to fill carry */
+			unsigned long to_fill = 8 - pbuf->carry_bytes;
+			/* bytes left over to be read */
+			unsigned long extra = to_align - to_fill;
+			void __iomem *dest;
+
+			/* fill carry... */
+			read_extra_bytes(pbuf, from, to_fill);
+			from += to_fill;
+			nbytes -= to_fill;
+
+			/* ...now write carry */
+			dest = pbuf->start + (pbuf->qw_written * sizeof(u64));
+
+			/*
+			 * The two checks immediately below cannot both be
+			 * true, hence the else.  If we have wrapped, we
+			 * cannot still be within the first block.
+			 * Conversely, if we are still in the first block, we
+			 * cannot have wrapped.  We do the wrap check first
+			 * as that is more likely.
+			 */
+			/* adjust if we've wrapped */
+			if (dest >= pbuf->end)
+				dest -= pbuf->size;
+			/* jump to SOP range if within the first block */
+			else if (pbuf->qw_written < PIO_BLOCK_QWS)
+				dest += SOP_DISTANCE;
+
+			carry8_write8(pbuf->carry, dest);
+			pbuf->qw_written++;
+
+			/* read any extra bytes to do final alignment */
+			/* this will overwrite anything in pbuf->carry */
+			read_low_bytes(pbuf, from, extra);
+			from += extra;
+			nbytes -= extra;
+		}
+
+		/* at this point, from is QW aligned */
+	}
+
+	if (pbuf->carry_bytes)
+		mid_copy_mix(pbuf, from, nbytes);
+	else
+		mid_copy_straight(pbuf, from, nbytes);
+}
+
+/*
+ * Segmented PIO Copy - end
+ *
+ * Write any remainder (in pbuf->carry) and finish writing the whole block.
+ *
+ * @pbuf: a number of blocks allocated within a PIO send context
+ */
+void seg_pio_copy_end(struct pio_buf *pbuf)
+{
+	void __iomem *dest = pbuf->start + (pbuf->qw_written * sizeof(u64));
+
+	/*
+	 * The two checks immediately below cannot both be true, hence the
+	 * else.  If we have wrapped, we cannot still be within the first
+	 * block.  Conversely, if we are still in the first block, we
+	 * cannot have wrapped.  We do the wrap check first as that is
+	 * more likely.
+	 */
+	/* adjust if we have wrapped */
+	if (dest >= pbuf->end)
+		dest -= pbuf->size;
+	/* jump to the SOP range if within the first block */
+	else if (pbuf->qw_written < PIO_BLOCK_QWS)
+		dest += SOP_DISTANCE;
+
+	/* write final bytes, if any */
+	if (carry_write8(pbuf, dest)) {
+		dest += sizeof(u64);
+		/*
+		 * NOTE: We do not need to recalculate whether dest needs
+		 * SOP_DISTANCE or not.
+		 *
+		 * If we are in the first block and the dangle write
+		 * keeps us in the same block, dest will need
+		 * to retain SOP_DISTANCE in the loop below.
+		 *
+		 * If we are in the first block and the dangle write pushes
+		 * us to the next block, then loop below will not run
+		 * and dest is not used.  Hence we do not need to update
+		 * it.
+		 *
+		 * If we are past the first block, then SOP_DISTANCE
+		 * was never added, so there is nothing to do.
+		 */
+	}
+
+	/* fill in rest of block */
+	while (((unsigned long)dest & PIO_BLOCK_MASK) != 0) {
+		writeq(0, dest);
+		dest += sizeof(u64);
+	}
+
+	/* finished with this buffer */
+	atomic_dec(&pbuf->sc->buffers_allocated);
+}
