Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 1775 insertions, 0 deletions

diff --git a/drivers/misc/mic/scif/scif_rma.c b/drivers/misc/mic/scif/scif_rma.c
new file mode 100644
index 000000000..e1f59b177
--- /dev/null
+++ b/drivers/misc/mic/scif/scif_rma.c
@@ -0,0 +1,1775 @@
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, 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.
+ *
+ * Intel SCIF driver.
+ *
+ */
+#include <linux/dma_remapping.h>
+#include <linux/pagemap.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/signal.h>
+
+#include "scif_main.h"
+#include "scif_map.h"
+
+/* Used to skip ulimit checks for registrations with SCIF_MAP_KERNEL flag */
+#define SCIF_MAP_ULIMIT 0x40
+
+bool scif_ulimit_check = 1;
+
+/**
+ * scif_rma_ep_init:
+ * @ep: end point
+ *
+ * Initialize RMA per EP data structures.
+ */
+void scif_rma_ep_init(struct scif_endpt *ep)
+{
+	struct scif_endpt_rma_info *rma = &ep->rma_info;
+
+	mutex_init(&rma->rma_lock);
+	init_iova_domain(&rma->iovad, PAGE_SIZE, SCIF_IOVA_START_PFN);
+	spin_lock_init(&rma->tc_lock);
+	mutex_init(&rma->mmn_lock);
+	INIT_LIST_HEAD(&rma->reg_list);
+	INIT_LIST_HEAD(&rma->remote_reg_list);
+	atomic_set(&rma->tw_refcount, 0);
+	atomic_set(&rma->tcw_refcount, 0);
+	atomic_set(&rma->tcw_total_pages, 0);
+	atomic_set(&rma->fence_refcount, 0);
+
+	rma->async_list_del = 0;
+	rma->dma_chan = NULL;
+	INIT_LIST_HEAD(&rma->mmn_list);
+	INIT_LIST_HEAD(&rma->vma_list);
+	init_waitqueue_head(&rma->markwq);
+}
+
+/**
+ * scif_rma_ep_can_uninit:
+ * @ep: end point
+ *
+ * Returns 1 if an endpoint can be uninitialized and 0 otherwise.
+ */
+int scif_rma_ep_can_uninit(struct scif_endpt *ep)
+{
+	int ret = 0;
+
+	mutex_lock(&ep->rma_info.rma_lock);
+	/* Destroy RMA Info only if both lists are empty */
+	if (list_empty(&ep->rma_info.reg_list) &&
+	    list_empty(&ep->rma_info.remote_reg_list) &&
+	    list_empty(&ep->rma_info.mmn_list) &&
+	    !atomic_read(&ep->rma_info.tw_refcount) &&
+	    !atomic_read(&ep->rma_info.tcw_refcount) &&
+	    !atomic_read(&ep->rma_info.fence_refcount))
+		ret = 1;
+	mutex_unlock(&ep->rma_info.rma_lock);
+	return ret;
+}
+
+/**
+ * scif_create_pinned_pages:
+ * @nr_pages: number of pages in window
+ * @prot: read/write protection
+ *
+ * Allocate and prepare a set of pinned pages.
+ */
+static struct scif_pinned_pages *
+scif_create_pinned_pages(int nr_pages, int prot)
+{
+	struct scif_pinned_pages *pin;
+
+	might_sleep();
+	pin = scif_zalloc(sizeof(*pin));
+	if (!pin)
+		goto error;
+
+	pin->pages = scif_zalloc(nr_pages * sizeof(*pin->pages));
+	if (!pin->pages)
+		goto error_free_pinned_pages;
+
+	pin->prot = prot;
+	pin->magic = SCIFEP_MAGIC;
+	return pin;
+
+error_free_pinned_pages:
+	scif_free(pin, sizeof(*pin));
+error:
+	return NULL;
+}
+
+/**
+ * scif_destroy_pinned_pages:
+ * @pin: A set of pinned pages.
+ *
+ * Deallocate resources for pinned pages.
+ */
+static int scif_destroy_pinned_pages(struct scif_pinned_pages *pin)
+{
+	int j;
+	int writeable = pin->prot & SCIF_PROT_WRITE;
+	int kernel = SCIF_MAP_KERNEL & pin->map_flags;
+
+	for (j = 0; j < pin->nr_pages; j++) {
+		if (pin->pages[j] && !kernel) {
+			if (writeable)
+				SetPageDirty(pin->pages[j]);
+			put_page(pin->pages[j]);
+		}
+	}
+
+	scif_free(pin->pages,
+		  pin->nr_pages * sizeof(*pin->pages));
+	scif_free(pin, sizeof(*pin));
+	return 0;
+}
+
+/*
+ * scif_create_window:
+ * @ep: end point
+ * @nr_pages: number of pages
+ * @offset: registration offset
+ * @temp: true if a temporary window is being created
+ *
+ * Allocate and prepare a self registration window.
+ */
+struct scif_window *scif_create_window(struct scif_endpt *ep, int nr_pages,
+				       s64 offset, bool temp)
+{
+	struct scif_window *window;
+
+	might_sleep();
+	window = scif_zalloc(sizeof(*window));
+	if (!window)
+		goto error;
+
+	window->dma_addr = scif_zalloc(nr_pages * sizeof(*window->dma_addr));
+	if (!window->dma_addr)
+		goto error_free_window;
+
+	window->num_pages = scif_zalloc(nr_pages * sizeof(*window->num_pages));
+	if (!window->num_pages)
+		goto error_free_window;
+
+	window->offset = offset;
+	window->ep = (u64)ep;
+	window->magic = SCIFEP_MAGIC;
+	window->reg_state = OP_IDLE;
+	init_waitqueue_head(&window->regwq);
+	window->unreg_state = OP_IDLE;
+	init_waitqueue_head(&window->unregwq);
+	INIT_LIST_HEAD(&window->list);
+	window->type = SCIF_WINDOW_SELF;
+	window->temp = temp;
+	return window;
+
+error_free_window:
+	scif_free(window->dma_addr,
+		  nr_pages * sizeof(*window->dma_addr));
+	scif_free(window, sizeof(*window));
+error:
+	return NULL;
+}
+
+/**
+ * scif_destroy_incomplete_window:
+ * @ep: end point
+ * @window: registration window
+ *
+ * Deallocate resources for self window.
+ */
+static void scif_destroy_incomplete_window(struct scif_endpt *ep,
+					   struct scif_window *window)
+{
+	int err;
+	int nr_pages = window->nr_pages;
+	struct scif_allocmsg *alloc = &window->alloc_handle;
+	struct scifmsg msg;
+
+retry:
+	/* Wait for a SCIF_ALLOC_GNT/REJ message */
+	err = wait_event_timeout(alloc->allocwq,
+				 alloc->state != OP_IN_PROGRESS,
+				 SCIF_NODE_ALIVE_TIMEOUT);
+	if (!err && scifdev_alive(ep))
+		goto retry;
+
+	mutex_lock(&ep->rma_info.rma_lock);
+	if (alloc->state == OP_COMPLETED) {
+		msg.uop = SCIF_FREE_VIRT;
+		msg.src = ep->port;
+		msg.payload[0] = ep->remote_ep;
+		msg.payload[1] = window->alloc_handle.vaddr;
+		msg.payload[2] = (u64)window;
+		msg.payload[3] = SCIF_REGISTER;
+		_scif_nodeqp_send(ep->remote_dev, &msg);
+	}
+	mutex_unlock(&ep->rma_info.rma_lock);
+
+	scif_free_window_offset(ep, window, window->offset);
+	scif_free(window->dma_addr, nr_pages * sizeof(*window->dma_addr));
+	scif_free(window->num_pages, nr_pages * sizeof(*window->num_pages));
+	scif_free(window, sizeof(*window));
+}
+
+/**
+ * scif_unmap_window:
+ * @remote_dev: SCIF remote device
+ * @window: registration window
+ *
+ * Delete any DMA mappings created for a registered self window
+ */
+void scif_unmap_window(struct scif_dev *remote_dev, struct scif_window *window)
+{
+	int j;
+
+	if (scif_is_iommu_enabled() && !scifdev_self(remote_dev)) {
+		if (window->st) {
+			dma_unmap_sg(&remote_dev->sdev->dev,
+				     window->st->sgl, window->st->nents,
+				     DMA_BIDIRECTIONAL);
+			sg_free_table(window->st);
+			kfree(window->st);
+			window->st = NULL;
+		}
+	} else {
+		for (j = 0; j < window->nr_contig_chunks; j++) {
+			if (window->dma_addr[j]) {
+				scif_unmap_single(window->dma_addr[j],
+						  remote_dev,
+						  window->num_pages[j] <<
+						  PAGE_SHIFT);
+				window->dma_addr[j] = 0x0;
+			}
+		}
+	}
+}
+
+static inline struct mm_struct *__scif_acquire_mm(void)
+{
+	if (scif_ulimit_check)
+		return get_task_mm(current);
+	return NULL;
+}
+
+static inline void __scif_release_mm(struct mm_struct *mm)
+{
+	if (mm)
+		mmput(mm);
+}
+
+static inline int
+__scif_dec_pinned_vm_lock(struct mm_struct *mm,
+			  int nr_pages, bool try_lock)
+{
+	if (!mm || !nr_pages || !scif_ulimit_check)
+		return 0;
+	if (try_lock) {
+		if (!down_write_trylock(&mm->mmap_sem)) {
+			dev_err(scif_info.mdev.this_device,
+				"%s %d err\n", __func__, __LINE__);
+			return -1;
+		}
+	} else {
+		down_write(&mm->mmap_sem);
+	}
+	mm->pinned_vm -= nr_pages;
+	up_write(&mm->mmap_sem);
+	return 0;
+}
+
+static inline int __scif_check_inc_pinned_vm(struct mm_struct *mm,
+					     int nr_pages)
+{
+	unsigned long locked, lock_limit;
+
+	if (!mm || !nr_pages || !scif_ulimit_check)
+		return 0;
+
+	locked = nr_pages;
+	locked += mm->pinned_vm;
+	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+	if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
+		dev_err(scif_info.mdev.this_device,
+			"locked(%lu) > lock_limit(%lu)\n",
+			locked, lock_limit);
+		return -ENOMEM;
+	}
+	mm->pinned_vm = locked;
+	return 0;
+}
+
+/**
+ * scif_destroy_window:
+ * @ep: end point
+ * @window: registration window
+ *
+ * Deallocate resources for self window.
+ */
+int scif_destroy_window(struct scif_endpt *ep, struct scif_window *window)
+{
+	int j;
+	struct scif_pinned_pages *pinned_pages = window->pinned_pages;
+	int nr_pages = window->nr_pages;
+
+	might_sleep();
+	if (!window->temp && window->mm) {
+		__scif_dec_pinned_vm_lock(window->mm, window->nr_pages, 0);
+		__scif_release_mm(window->mm);
+		window->mm = NULL;
+	}
+
+	scif_free_window_offset(ep, window, window->offset);
+	scif_unmap_window(ep->remote_dev, window);
+	/*
+	 * Decrement references for this set of pinned pages from
+	 * this window.
+	 */
+	j = atomic_sub_return(1, &pinned_pages->ref_count);
+	if (j < 0)
+		dev_err(scif_info.mdev.this_device,
+			"%s %d incorrect ref count %d\n",
+			__func__, __LINE__, j);
+	/*
+	 * If the ref count for pinned_pages is zero then someone
+	 * has already called scif_unpin_pages() for it and we should
+	 * destroy the page cache.
+	 */
+	if (!j)
+		scif_destroy_pinned_pages(window->pinned_pages);
+	scif_free(window->dma_addr, nr_pages * sizeof(*window->dma_addr));
+	scif_free(window->num_pages, nr_pages * sizeof(*window->num_pages));
+	window->magic = 0;
+	scif_free(window, sizeof(*window));
+	return 0;
+}
+
+/**
+ * scif_create_remote_lookup:
+ * @remote_dev: SCIF remote device
+ * @window: remote window
+ *
+ * Allocate and prepare lookup entries for the remote
+ * end to copy over the physical addresses.
+ * Returns 0 on success and appropriate errno on failure.
+ */
+static int scif_create_remote_lookup(struct scif_dev *remote_dev,
+				     struct scif_window *window)
+{
+	int i, j, err = 0;
+	int nr_pages = window->nr_pages;
+	bool vmalloc_dma_phys, vmalloc_num_pages;
+
+	might_sleep();
+	/* Map window */
+	err = scif_map_single(&window->mapped_offset,
+			      window, remote_dev, sizeof(*window));
+	if (err)
+		goto error_window;
+
+	/* Compute the number of lookup entries. 21 == 2MB Shift */
+	window->nr_lookup = ALIGN(nr_pages * PAGE_SIZE,
+					((2) * 1024 * 1024)) >> 21;
+
+	window->dma_addr_lookup.lookup =
+		scif_alloc_coherent(&window->dma_addr_lookup.offset,
+				    remote_dev, window->nr_lookup *
+				    sizeof(*window->dma_addr_lookup.lookup),
+				    GFP_KERNEL | __GFP_ZERO);
+	if (!window->dma_addr_lookup.lookup) {
+		err = -ENOMEM;
+		goto error_window;
+	}
+
+	window->num_pages_lookup.lookup =
+		scif_alloc_coherent(&window->num_pages_lookup.offset,
+				    remote_dev, window->nr_lookup *
+				    sizeof(*window->num_pages_lookup.lookup),
+				    GFP_KERNEL | __GFP_ZERO);
+	if (!window->num_pages_lookup.lookup) {
+		err = -ENOMEM;
+		goto error_window;
+	}
+
+	vmalloc_dma_phys = is_vmalloc_addr(&window->dma_addr[0]);
+	vmalloc_num_pages = is_vmalloc_addr(&window->num_pages[0]);
+
+	/* Now map each of the pages containing physical addresses */
+	for (i = 0, j = 0; i < nr_pages; i += SCIF_NR_ADDR_IN_PAGE, j++) {
+		err = scif_map_page(&window->dma_addr_lookup.lookup[j],
+				    vmalloc_dma_phys ?
+				    vmalloc_to_page(&window->dma_addr[i]) :
+				    virt_to_page(&window->dma_addr[i]),
+				    remote_dev);
+		if (err)
+			goto error_window;
+		err = scif_map_page(&window->num_pages_lookup.lookup[j],
+				    vmalloc_num_pages ?
+				    vmalloc_to_page(&window->num_pages[i]) :
+				    virt_to_page(&window->num_pages[i]),
+				    remote_dev);
+		if (err)
+			goto error_window;
+	}
+	return 0;
+error_window:
+	return err;
+}
+
+/**
+ * scif_destroy_remote_lookup:
+ * @remote_dev: SCIF remote device
+ * @window: remote window
+ *
+ * Destroy lookup entries used for the remote
+ * end to copy over the physical addresses.
+ */
+static void scif_destroy_remote_lookup(struct scif_dev *remote_dev,
+				       struct scif_window *window)
+{
+	int i, j;
+
+	if (window->nr_lookup) {
+		struct scif_rma_lookup *lup = &window->dma_addr_lookup;
+		struct scif_rma_lookup *npup = &window->num_pages_lookup;
+
+		for (i = 0, j = 0; i < window->nr_pages;
+			i += SCIF_NR_ADDR_IN_PAGE, j++) {
+			if (lup->lookup && lup->lookup[j])
+				scif_unmap_single(lup->lookup[j],
+						  remote_dev,
+						  PAGE_SIZE);
+			if (npup->lookup && npup->lookup[j])
+				scif_unmap_single(npup->lookup[j],
+						  remote_dev,
+						  PAGE_SIZE);
+		}
+		if (lup->lookup)
+			scif_free_coherent(lup->lookup, lup->offset,
+					   remote_dev, window->nr_lookup *
+					   sizeof(*lup->lookup));
+		if (npup->lookup)
+			scif_free_coherent(npup->lookup, npup->offset,
+					   remote_dev, window->nr_lookup *
+					   sizeof(*npup->lookup));
+		if (window->mapped_offset)
+			scif_unmap_single(window->mapped_offset,
+					  remote_dev, sizeof(*window));
+		window->nr_lookup = 0;
+	}
+}
+
+/**
+ * scif_create_remote_window:
+ * @ep: end point
+ * @nr_pages: number of pages in window
+ *
+ * Allocate and prepare a remote registration window.
+ */
+static struct scif_window *
+scif_create_remote_window(struct scif_dev *scifdev, int nr_pages)
+{
+	struct scif_window *window;
+
+	might_sleep();
+	window = scif_zalloc(sizeof(*window));
+	if (!window)
+		goto error_ret;
+
+	window->magic = SCIFEP_MAGIC;
+	window->nr_pages = nr_pages;
+
+	window->dma_addr = scif_zalloc(nr_pages * sizeof(*window->dma_addr));
+	if (!window->dma_addr)
+		goto error_window;
+
+	window->num_pages = scif_zalloc(nr_pages *
+					sizeof(*window->num_pages));
+	if (!window->num_pages)
+		goto error_window;
+
+	if (scif_create_remote_lookup(scifdev, window))
+		goto error_window;
+
+	window->type = SCIF_WINDOW_PEER;
+	window->unreg_state = OP_IDLE;
+	INIT_LIST_HEAD(&window->list);
+	return window;
+error_window:
+	scif_destroy_remote_window(window);
+error_ret:
+	return NULL;
+}
+
+/**
+ * scif_destroy_remote_window:
+ * @ep: end point
+ * @window: remote registration window
+ *
+ * Deallocate resources for remote window.
+ */
+void
+scif_destroy_remote_window(struct scif_window *window)
+{
+	scif_free(window->dma_addr, window->nr_pages *
+		  sizeof(*window->dma_addr));
+	scif_free(window->num_pages, window->nr_pages *
+		  sizeof(*window->num_pages));
+	window->magic = 0;
+	scif_free(window, sizeof(*window));
+}
+
+/**
+ * scif_iommu_map: create DMA mappings if the IOMMU is enabled
+ * @remote_dev: SCIF remote device
+ * @window: remote registration window
+ *
+ * Map the physical pages using dma_map_sg(..) and then detect the number
+ * of contiguous DMA mappings allocated
+ */
+static int scif_iommu_map(struct scif_dev *remote_dev,
+			  struct scif_window *window)
+{
+	struct scatterlist *sg;
+	int i, err;
+	scif_pinned_pages_t pin = window->pinned_pages;
+
+	window->st = kzalloc(sizeof(*window->st), GFP_KERNEL);
+	if (!window->st)
+		return -ENOMEM;
+
+	err = sg_alloc_table(window->st, window->nr_pages, GFP_KERNEL);
+	if (err)
+		return err;
+
+	for_each_sg(window->st->sgl, sg, window->st->nents, i)
+		sg_set_page(sg, pin->pages[i], PAGE_SIZE, 0x0);
+
+	err = dma_map_sg(&remote_dev->sdev->dev, window->st->sgl,
+			 window->st->nents, DMA_BIDIRECTIONAL);
+	if (!err)
+		return -ENOMEM;
+	/* Detect contiguous ranges of DMA mappings */
+	sg = window->st->sgl;
+	for (i = 0; sg; i++) {
+		dma_addr_t last_da;
+
+		window->dma_addr[i] = sg_dma_address(sg);
+		window->num_pages[i] = sg_dma_len(sg) >> PAGE_SHIFT;
+		last_da = sg_dma_address(sg) + sg_dma_len(sg);
+		while ((sg = sg_next(sg)) && sg_dma_address(sg) == last_da) {
+			window->num_pages[i] +=
+				(sg_dma_len(sg) >> PAGE_SHIFT);
+			last_da = window->dma_addr[i] +
+				sg_dma_len(sg);
+		}
+		window->nr_contig_chunks++;
+	}
+	return 0;
+}
+
+/**
+ * scif_map_window:
+ * @remote_dev: SCIF remote device
+ * @window: self registration window
+ *
+ * Map pages of a window into the aperture/PCI.
+ * Also determine addresses required for DMA.
+ */
+int
+scif_map_window(struct scif_dev *remote_dev, struct scif_window *window)
+{
+	int i, j, k, err = 0, nr_contig_pages;
+	scif_pinned_pages_t pin;
+	phys_addr_t phys_prev, phys_curr;
+
+	might_sleep();
+
+	pin = window->pinned_pages;
+
+	if (intel_iommu_enabled && !scifdev_self(remote_dev))
+		return scif_iommu_map(remote_dev, window);
+
+	for (i = 0, j = 0; i < window->nr_pages; i += nr_contig_pages, j++) {
+		phys_prev = page_to_phys(pin->pages[i]);
+		nr_contig_pages = 1;
+
+		/* Detect physically contiguous chunks */
+		for (k = i + 1; k < window->nr_pages; k++) {
+			phys_curr = page_to_phys(pin->pages[k]);
+			if (phys_curr != (phys_prev + PAGE_SIZE))
+				break;
+			phys_prev = phys_curr;
+			nr_contig_pages++;
+		}
+		window->num_pages[j] = nr_contig_pages;
+		window->nr_contig_chunks++;
+		if (scif_is_mgmt_node()) {
+			/*
+			 * Management node has to deal with SMPT on X100 and
+			 * hence the DMA mapping is required
+			 */
+			err = scif_map_single(&window->dma_addr[j],
+					      phys_to_virt(page_to_phys(
+							   pin->pages[i])),
+					      remote_dev,
+					      nr_contig_pages << PAGE_SHIFT);
+			if (err)
+				return err;
+		} else {
+			window->dma_addr[j] = page_to_phys(pin->pages[i]);
+		}
+	}
+	return err;
+}
+
+/**
+ * scif_send_scif_unregister:
+ * @ep: end point
+ * @window: self registration window
+ *
+ * Send a SCIF_UNREGISTER message.
+ */
+static int scif_send_scif_unregister(struct scif_endpt *ep,
+				     struct scif_window *window)
+{
+	struct scifmsg msg;
+
+	msg.uop = SCIF_UNREGISTER;
+	msg.src = ep->port;
+	msg.payload[0] = window->alloc_handle.vaddr;
+	msg.payload[1] = (u64)window;
+	return scif_nodeqp_send(ep->remote_dev, &msg);
+}
+
+/**
+ * scif_unregister_window:
+ * @window: self registration window
+ *
+ * Send an unregistration request and wait for a response.
+ */
+int scif_unregister_window(struct scif_window *window)
+{
+	int err = 0;
+	struct scif_endpt *ep = (struct scif_endpt *)window->ep;
+	bool send_msg = false;
+
+	might_sleep();
+	switch (window->unreg_state) {
+	case OP_IDLE:
+	{
+		window->unreg_state = OP_IN_PROGRESS;
+		send_msg = true;
+		/* fall through */
+	}
+	case OP_IN_PROGRESS:
+	{
+		scif_get_window(window, 1);
+		mutex_unlock(&ep->rma_info.rma_lock);
+		if (send_msg) {
+			err = scif_send_scif_unregister(ep, window);
+			if (err) {
+				window->unreg_state = OP_COMPLETED;
+				goto done;
+			}
+		} else {
+			/* Return ENXIO since unregistration is in progress */
+			mutex_lock(&ep->rma_info.rma_lock);
+			return -ENXIO;
+		}
+retry:
+		/* Wait for a SCIF_UNREGISTER_(N)ACK message */
+		err = wait_event_timeout(window->unregwq,
+					 window->unreg_state != OP_IN_PROGRESS,
+					 SCIF_NODE_ALIVE_TIMEOUT);
+		if (!err && scifdev_alive(ep))
+			goto retry;
+		if (!err) {
+			err = -ENODEV;
+			window->unreg_state = OP_COMPLETED;
+			dev_err(scif_info.mdev.this_device,
+				"%s %d err %d\n", __func__, __LINE__, err);
+		}
+		if (err > 0)
+			err = 0;
+done:
+		mutex_lock(&ep->rma_info.rma_lock);
+		scif_put_window(window, 1);
+		break;
+	}
+	case OP_FAILED:
+	{
+		if (!scifdev_alive(ep)) {
+			err = -ENODEV;
+			window->unreg_state = OP_COMPLETED;
+		}
+		break;
+	}
+	case OP_COMPLETED:
+		break;
+	default:
+		err = -ENODEV;
+	}
+
+	if (window->unreg_state == OP_COMPLETED && window->ref_count)
+		scif_put_window(window, window->nr_pages);
+
+	if (!window->ref_count) {
+		atomic_inc(&ep->rma_info.tw_refcount);
+		list_del_init(&window->list);
+		scif_free_window_offset(ep, window, window->offset);
+		mutex_unlock(&ep->rma_info.rma_lock);
+		if ((!!(window->pinned_pages->map_flags & SCIF_MAP_KERNEL)) &&
+		    scifdev_alive(ep)) {
+			scif_drain_dma_intr(ep->remote_dev->sdev,
+					    ep->rma_info.dma_chan);
+		} else {
+			if (!__scif_dec_pinned_vm_lock(window->mm,
+						       window->nr_pages, 1)) {
+				__scif_release_mm(window->mm);
+				window->mm = NULL;
+			}
+		}
+		scif_queue_for_cleanup(window, &scif_info.rma);
+		mutex_lock(&ep->rma_info.rma_lock);
+	}
+	return err;
+}
+
+/**
+ * scif_send_alloc_request:
+ * @ep: end point
+ * @window: self registration window
+ *
+ * Send a remote window allocation request
+ */
+static int scif_send_alloc_request(struct scif_endpt *ep,
+				   struct scif_window *window)
+{
+	struct scifmsg msg;
+	struct scif_allocmsg *alloc = &window->alloc_handle;
+
+	/* Set up the Alloc Handle */
+	alloc->state = OP_IN_PROGRESS;
+	init_waitqueue_head(&alloc->allocwq);
+
+	/* Send out an allocation request */
+	msg.uop = SCIF_ALLOC_REQ;
+	msg.payload[1] = window->nr_pages;
+	msg.payload[2] = (u64)&window->alloc_handle;
+	return _scif_nodeqp_send(ep->remote_dev, &msg);
+}
+
+/**
+ * scif_prep_remote_window:
+ * @ep: end point
+ * @window: self registration window
+ *
+ * Send a remote window allocation request, wait for an allocation response,
+ * and prepares the remote window by copying over the page lists
+ */
+static int scif_prep_remote_window(struct scif_endpt *ep,
+				   struct scif_window *window)
+{
+	struct scifmsg msg;
+	struct scif_window *remote_window;
+	struct scif_allocmsg *alloc = &window->alloc_handle;
+	dma_addr_t *dma_phys_lookup, *tmp, *num_pages_lookup, *tmp1;
+	int i = 0, j = 0;
+	int nr_contig_chunks, loop_nr_contig_chunks;
+	int remaining_nr_contig_chunks, nr_lookup;
+	int err, map_err;
+
+	map_err = scif_map_window(ep->remote_dev, window);
+	if (map_err)
+		dev_err(&ep->remote_dev->sdev->dev,
+			"%s %d map_err %d\n", __func__, __LINE__, map_err);
+	remaining_nr_contig_chunks = window->nr_contig_chunks;
+	nr_contig_chunks = window->nr_contig_chunks;
+retry:
+	/* Wait for a SCIF_ALLOC_GNT/REJ message */
+	err = wait_event_timeout(alloc->allocwq,
+				 alloc->state != OP_IN_PROGRESS,
+				 SCIF_NODE_ALIVE_TIMEOUT);
+	mutex_lock(&ep->rma_info.rma_lock);
+	/* Synchronize with the thread waking up allocwq */
+	mutex_unlock(&ep->rma_info.rma_lock);
+	if (!err && scifdev_alive(ep))
+		goto retry;
+
+	if (!err)
+		err = -ENODEV;
+
+	if (err > 0)
+		err = 0;
+	else
+		return err;
+
+	/* Bail out. The remote end rejected this request */
+	if (alloc->state == OP_FAILED)
+		return -ENOMEM;
+
+	if (map_err) {
+		dev_err(&ep->remote_dev->sdev->dev,
+			"%s %d err %d\n", __func__, __LINE__, map_err);
+		msg.uop = SCIF_FREE_VIRT;
+		msg.src = ep->port;
+		msg.payload[0] = ep->remote_ep;
+		msg.payload[1] = window->alloc_handle.vaddr;
+		msg.payload[2] = (u64)window;
+		msg.payload[3] = SCIF_REGISTER;
+		spin_lock(&ep->lock);
+		if (ep->state == SCIFEP_CONNECTED)
+			err = _scif_nodeqp_send(ep->remote_dev, &msg);
+		else
+			err = -ENOTCONN;
+		spin_unlock(&ep->lock);
+		return err;
+	}
+
+	remote_window = scif_ioremap(alloc->phys_addr, sizeof(*window),
+				     ep->remote_dev);
+
+	/* Compute the number of lookup entries. 21 == 2MB Shift */
+	nr_lookup = ALIGN(nr_contig_chunks, SCIF_NR_ADDR_IN_PAGE)
+			  >> ilog2(SCIF_NR_ADDR_IN_PAGE);
+
+	dma_phys_lookup =
+		scif_ioremap(remote_window->dma_addr_lookup.offset,
+			     nr_lookup *
+			     sizeof(*remote_window->dma_addr_lookup.lookup),
+			     ep->remote_dev);
+	num_pages_lookup =
+		scif_ioremap(remote_window->num_pages_lookup.offset,
+			     nr_lookup *
+			     sizeof(*remote_window->num_pages_lookup.lookup),
+			     ep->remote_dev);
+
+	while (remaining_nr_contig_chunks) {
+		loop_nr_contig_chunks = min_t(int, remaining_nr_contig_chunks,
+					      (int)SCIF_NR_ADDR_IN_PAGE);
+		/* #1/2 - Copy  physical addresses over to the remote side */
+
+		/* #2/2 - Copy DMA addresses (addresses that are fed into the
+		 * DMA engine) We transfer bus addresses which are then
+		 * converted into a MIC physical address on the remote
+		 * side if it is a MIC, if the remote node is a mgmt node we
+		 * transfer the MIC physical address
+		 */
+		tmp = scif_ioremap(dma_phys_lookup[j],
+				   loop_nr_contig_chunks *
+				   sizeof(*window->dma_addr),
+				   ep->remote_dev);
+		tmp1 = scif_ioremap(num_pages_lookup[j],
+				    loop_nr_contig_chunks *
+				    sizeof(*window->num_pages),
+				    ep->remote_dev);
+		if (scif_is_mgmt_node()) {
+			memcpy_toio((void __force __iomem *)tmp,
+				    &window->dma_addr[i], loop_nr_contig_chunks
+				    * sizeof(*window->dma_addr));
+			memcpy_toio((void __force __iomem *)tmp1,
+				    &window->num_pages[i], loop_nr_contig_chunks
+				    * sizeof(*window->num_pages));
+		} else {
+			if (scifdev_is_p2p(ep->remote_dev)) {
+				/*
+				 * add remote node's base address for this node
+				 * to convert it into a MIC address
+				 */
+				int m;
+				dma_addr_t dma_addr;
+
+				for (m = 0; m < loop_nr_contig_chunks; m++) {
+					dma_addr = window->dma_addr[i + m] +
+						ep->remote_dev->base_addr;
+					writeq(dma_addr,
+					       (void __force __iomem *)&tmp[m]);
+				}
+				memcpy_toio((void __force __iomem *)tmp1,
+					    &window->num_pages[i],
+					    loop_nr_contig_chunks
+					    * sizeof(*window->num_pages));
+			} else {
+				/* Mgmt node or loopback - transfer DMA
+				 * addresses as is, this is the same as a
+				 * MIC physical address (we use the dma_addr
+				 * and not the phys_addr array since the
+				 * phys_addr is only setup if there is a mmap()
+				 * request from the mgmt node)
+				 */
+				memcpy_toio((void __force __iomem *)tmp,
+					    &window->dma_addr[i],
+					    loop_nr_contig_chunks *
+					    sizeof(*window->dma_addr));
+				memcpy_toio((void __force __iomem *)tmp1,
+					    &window->num_pages[i],
+					    loop_nr_contig_chunks *
+					    sizeof(*window->num_pages));
+			}
+		}
+		remaining_nr_contig_chunks -= loop_nr_contig_chunks;
+		i += loop_nr_contig_chunks;
+		j++;
+		scif_iounmap(tmp, loop_nr_contig_chunks *
+			     sizeof(*window->dma_addr), ep->remote_dev);
+		scif_iounmap(tmp1, loop_nr_contig_chunks *
+			     sizeof(*window->num_pages), ep->remote_dev);
+	}
+
+	/* Prepare the remote window for the peer */
+	remote_window->peer_window = (u64)window;
+	remote_window->offset = window->offset;
+	remote_window->prot = window->prot;
+	remote_window->nr_contig_chunks = nr_contig_chunks;
+	remote_window->ep = ep->remote_ep;
+	scif_iounmap(num_pages_lookup,
+		     nr_lookup *
+		     sizeof(*remote_window->num_pages_lookup.lookup),
+		     ep->remote_dev);
+	scif_iounmap(dma_phys_lookup,
+		     nr_lookup *
+		     sizeof(*remote_window->dma_addr_lookup.lookup),
+		     ep->remote_dev);
+	scif_iounmap(remote_window, sizeof(*remote_window), ep->remote_dev);
+	window->peer_window = alloc->vaddr;
+	return err;
+}
+
+/**
+ * scif_send_scif_register:
+ * @ep: end point
+ * @window: self registration window
+ *
+ * Send a SCIF_REGISTER message if EP is connected and wait for a
+ * SCIF_REGISTER_(N)ACK message else send a SCIF_FREE_VIRT
+ * message so that the peer can free its remote window allocated earlier.
+ */
+static int scif_send_scif_register(struct scif_endpt *ep,
+				   struct scif_window *window)
+{
+	int err = 0;
+	struct scifmsg msg;
+
+	msg.src = ep->port;
+	msg.payload[0] = ep->remote_ep;
+	msg.payload[1] = window->alloc_handle.vaddr;
+	msg.payload[2] = (u64)window;
+	spin_lock(&ep->lock);
+	if (ep->state == SCIFEP_CONNECTED) {
+		msg.uop = SCIF_REGISTER;
+		window->reg_state = OP_IN_PROGRESS;
+		err = _scif_nodeqp_send(ep->remote_dev, &msg);
+		spin_unlock(&ep->lock);
+		if (!err) {
+retry:
+			/* Wait for a SCIF_REGISTER_(N)ACK message */
+			err = wait_event_timeout(window->regwq,
+						 window->reg_state !=
+						 OP_IN_PROGRESS,
+						 SCIF_NODE_ALIVE_TIMEOUT);
+			if (!err && scifdev_alive(ep))
+				goto retry;
+			err = !err ? -ENODEV : 0;
+			if (window->reg_state == OP_FAILED)
+				err = -ENOTCONN;
+		}
+	} else {
+		msg.uop = SCIF_FREE_VIRT;
+		msg.payload[3] = SCIF_REGISTER;
+		err = _scif_nodeqp_send(ep->remote_dev, &msg);
+		spin_unlock(&ep->lock);
+		if (!err)
+			err = -ENOTCONN;
+	}
+	return err;
+}
+
+/**
+ * scif_get_window_offset:
+ * @ep: end point descriptor
+ * @flags: flags
+ * @offset: offset hint
+ * @num_pages: number of pages
+ * @out_offset: computed offset returned by reference.
+ *
+ * Compute/Claim a new offset for this EP.
+ */
+int scif_get_window_offset(struct scif_endpt *ep, int flags, s64 offset,
+			   int num_pages, s64 *out_offset)
+{
+	s64 page_index;
+	struct iova *iova_ptr;
+	int err = 0;
+
+	if (flags & SCIF_MAP_FIXED) {
+		page_index = SCIF_IOVA_PFN(offset);
+		iova_ptr = reserve_iova(&ep->rma_info.iovad, page_index,
+					page_index + num_pages - 1);
+		if (!iova_ptr)
+			err = -EADDRINUSE;
+	} else {
+		iova_ptr = alloc_iova(&ep->rma_info.iovad, num_pages,
+				      SCIF_DMA_63BIT_PFN - 1, 0);
+		if (!iova_ptr)
+			err = -ENOMEM;
+	}
+	if (!err)
+		*out_offset = (iova_ptr->pfn_lo) << PAGE_SHIFT;
+	return err;
+}
+
+/**
+ * scif_free_window_offset:
+ * @ep: end point descriptor
+ * @window: registration window
+ * @offset: Offset to be freed
+ *
+ * Free offset for this EP. The callee is supposed to grab
+ * the RMA mutex before calling this API.
+ */
+void scif_free_window_offset(struct scif_endpt *ep,
+			     struct scif_window *window, s64 offset)
+{
+	if ((window && !window->offset_freed) || !window) {
+		free_iova(&ep->rma_info.iovad, offset >> PAGE_SHIFT);
+		if (window)
+			window->offset_freed = true;
+	}
+}
+
+/**
+ * scif_alloc_req: Respond to SCIF_ALLOC_REQ interrupt message
+ * @msg:        Interrupt message
+ *
+ * Remote side is requesting a memory allocation.
+ */
+void scif_alloc_req(struct scif_dev *scifdev, struct scifmsg *msg)
+{
+	int err;
+	struct scif_window *window = NULL;
+	int nr_pages = msg->payload[1];
+
+	window = scif_create_remote_window(scifdev, nr_pages);
+	if (!window) {
+		err = -ENOMEM;
+		goto error;
+	}
+
+	/* The peer's allocation request is granted */
+	msg->uop = SCIF_ALLOC_GNT;
+	msg->payload[0] = (u64)window;
+	msg->payload[1] = window->mapped_offset;
+	err = scif_nodeqp_send(scifdev, msg);
+	if (err)
+		scif_destroy_remote_window(window);
+	return;
+error:
+	/* The peer's allocation request is rejected */
+	dev_err(&scifdev->sdev->dev,
+		"%s %d error %d alloc_ptr %p nr_pages 0x%x\n",
+		__func__, __LINE__, err, window, nr_pages);
+	msg->uop = SCIF_ALLOC_REJ;
+	scif_nodeqp_send(scifdev, msg);
+}
+
+/**
+ * scif_alloc_gnt_rej: Respond to SCIF_ALLOC_GNT/REJ interrupt message
+ * @msg:        Interrupt message
+ *
+ * Remote side responded to a memory allocation.
+ */
+void scif_alloc_gnt_rej(struct scif_dev *scifdev, struct scifmsg *msg)
+{
+	struct scif_allocmsg *handle = (struct scif_allocmsg *)msg->payload[2];
+	struct scif_window *window = container_of(handle, struct scif_window,
+						  alloc_handle);
+	struct scif_endpt *ep = (struct scif_endpt *)window->ep;
+
+	mutex_lock(&ep->rma_info.rma_lock);
+	handle->vaddr = msg->payload[0];
+	handle->phys_addr = msg->payload[1];
+	if (msg->uop == SCIF_ALLOC_GNT)
+		handle->state = OP_COMPLETED;
+	else
+		handle->state = OP_FAILED;
+	wake_up(&handle->allocwq);
+	mutex_unlock(&ep->rma_info.rma_lock);
+}
+
+/**
+ * scif_free_virt: Respond to SCIF_FREE_VIRT interrupt message
+ * @msg:        Interrupt message
+ *
+ * Free up memory kmalloc'd earlier.
+ */
+void scif_free_virt(struct scif_dev *scifdev, struct scifmsg *msg)
+{
+	struct scif_window *window = (struct scif_window *)msg->payload[1];
+
+	scif_destroy_remote_window(window);
+}
+
+static void
+scif_fixup_aper_base(struct scif_dev *dev, struct scif_window *window)
+{
+	int j;
+	struct scif_hw_dev *sdev = dev->sdev;
+	phys_addr_t apt_base = 0;
+
+	/*
+	 * Add the aperture base if the DMA address is not card relative
+	 * since the DMA addresses need to be an offset into the bar
+	 */
+	if (!scifdev_self(dev) && window->type == SCIF_WINDOW_PEER &&
+	    sdev->aper && !sdev->card_rel_da)
+		apt_base = sdev->aper->pa;
+	else
+		return;
+
+	for (j = 0; j < window->nr_contig_chunks; j++) {
+		if (window->num_pages[j])
+			window->dma_addr[j] += apt_base;
+		else
+			break;
+	}
+}
+
+/**
+ * scif_recv_reg: Respond to SCIF_REGISTER interrupt message
+ * @msg:        Interrupt message
+ *
+ * Update remote window list with a new registered window.
+ */
+void scif_recv_reg(struct scif_dev *scifdev, struct scifmsg *msg)
+{
+	struct scif_endpt *ep = (struct scif_endpt *)msg->payload[0];
+	struct scif_window *window =
+		(struct scif_window *)msg->payload[1];
+
+	mutex_lock(&ep->rma_info.rma_lock);
+	spin_lock(&ep->lock);
+	if (ep->state == SCIFEP_CONNECTED) {
+		msg->uop = SCIF_REGISTER_ACK;
+		scif_nodeqp_send(ep->remote_dev, msg);
+		scif_fixup_aper_base(ep->remote_dev, window);
+		/* No further failures expected. Insert new window */
+		scif_insert_window(window, &ep->rma_info.remote_reg_list);
+	} else {
+		msg->uop = SCIF_REGISTER_NACK;
+		scif_nodeqp_send(ep->remote_dev, msg);
+	}
+	spin_unlock(&ep->lock);
+	mutex_unlock(&ep->rma_info.rma_lock);
+	/* free up any lookup resources now that page lists are transferred */
+	scif_destroy_remote_lookup(ep->remote_dev, window);
+	/*
+	 * We could not insert the window but we need to
+	 * destroy the window.
+	 */
+	if (msg->uop == SCIF_REGISTER_NACK)
+		scif_destroy_remote_window(window);
+}
+
+/**
+ * scif_recv_unreg: Respond to SCIF_UNREGISTER interrupt message
+ * @msg:        Interrupt message
+ *
+ * Remove window from remote registration list;
+ */
+void scif_recv_unreg(struct scif_dev *scifdev, struct scifmsg *msg)
+{
+	struct scif_rma_req req;
+	struct scif_window *window = NULL;
+	struct scif_window *recv_window =
+		(struct scif_window *)msg->payload[0];
+	struct scif_endpt *ep;
+	int del_window = 0;
+
+	ep = (struct scif_endpt *)recv_window->ep;
+	req.out_window = &window;
+	req.offset = recv_window->offset;
+	req.prot = 0;
+	req.nr_bytes = recv_window->nr_pages << PAGE_SHIFT;
+	req.type = SCIF_WINDOW_FULL;
+	req.head = &ep->rma_info.remote_reg_list;
+	msg->payload[0] = ep->remote_ep;
+
+	mutex_lock(&ep->rma_info.rma_lock);
+	/* Does a valid window exist? */
+	if (scif_query_window(&req)) {
+		dev_err(&scifdev->sdev->dev,
+			"%s %d -ENXIO\n", __func__, __LINE__);
+		msg->uop = SCIF_UNREGISTER_ACK;
+		goto error;
+	}
+	if (window) {
+		if (window->ref_count)
+			scif_put_window(window, window->nr_pages);
+		else
+			dev_err(&scifdev->sdev->dev,
+				"%s %d ref count should be +ve\n",
+				__func__, __LINE__);
+		window->unreg_state = OP_COMPLETED;
+		if (!window->ref_count) {
+			msg->uop = SCIF_UNREGISTER_ACK;
+			atomic_inc(&ep->rma_info.tw_refcount);
+			ep->rma_info.async_list_del = 1;
+			list_del_init(&window->list);
+			del_window = 1;
+		} else {
+			/* NACK! There are valid references to this window */
+			msg->uop = SCIF_UNREGISTER_NACK;
+		}
+	} else {
+		/* The window did not make its way to the list at all. ACK */
+		msg->uop = SCIF_UNREGISTER_ACK;
+		scif_destroy_remote_window(recv_window);
+	}
+error:
+	mutex_unlock(&ep->rma_info.rma_lock);
+	if (del_window)
+		scif_drain_dma_intr(ep->remote_dev->sdev,
+				    ep->rma_info.dma_chan);
+	scif_nodeqp_send(ep->remote_dev, msg);
+	if (del_window)
+		scif_queue_for_cleanup(window, &scif_info.rma);
+}
+
+/**
+ * scif_recv_reg_ack: Respond to SCIF_REGISTER_ACK interrupt message
+ * @msg:        Interrupt message
+ *
+ * Wake up the window waiting to complete registration.
+ */
+void scif_recv_reg_ack(struct scif_dev *scifdev, struct scifmsg *msg)
+{
+	struct scif_window *window =
+		(struct scif_window *)msg->payload[2];
+	struct scif_endpt *ep = (struct scif_endpt *)window->ep;
+
+	mutex_lock(&ep->rma_info.rma_lock);
+	window->reg_state = OP_COMPLETED;
+	wake_up(&window->regwq);
+	mutex_unlock(&ep->rma_info.rma_lock);
+}
+
+/**
+ * scif_recv_reg_nack: Respond to SCIF_REGISTER_NACK interrupt message
+ * @msg:        Interrupt message
+ *
+ * Wake up the window waiting to inform it that registration
+ * cannot be completed.
+ */
+void scif_recv_reg_nack(struct scif_dev *scifdev, struct scifmsg *msg)
+{
+	struct scif_window *window =
+		(struct scif_window *)msg->payload[2];
+	struct scif_endpt *ep = (struct scif_endpt *)window->ep;
+
+	mutex_lock(&ep->rma_info.rma_lock);
+	window->reg_state = OP_FAILED;
+	wake_up(&window->regwq);
+	mutex_unlock(&ep->rma_info.rma_lock);
+}
+
+/**
+ * scif_recv_unreg_ack: Respond to SCIF_UNREGISTER_ACK interrupt message
+ * @msg:        Interrupt message
+ *
+ * Wake up the window waiting to complete unregistration.
+ */
+void scif_recv_unreg_ack(struct scif_dev *scifdev, struct scifmsg *msg)
+{
+	struct scif_window *window =
+		(struct scif_window *)msg->payload[1];
+	struct scif_endpt *ep = (struct scif_endpt *)window->ep;
+
+	mutex_lock(&ep->rma_info.rma_lock);
+	window->unreg_state = OP_COMPLETED;
+	wake_up(&window->unregwq);
+	mutex_unlock(&ep->rma_info.rma_lock);
+}
+
+/**
+ * scif_recv_unreg_nack: Respond to SCIF_UNREGISTER_NACK interrupt message
+ * @msg:        Interrupt message
+ *
+ * Wake up the window waiting to inform it that unregistration
+ * cannot be completed immediately.
+ */
+void scif_recv_unreg_nack(struct scif_dev *scifdev, struct scifmsg *msg)
+{
+	struct scif_window *window =
+		(struct scif_window *)msg->payload[1];
+	struct scif_endpt *ep = (struct scif_endpt *)window->ep;
+
+	mutex_lock(&ep->rma_info.rma_lock);
+	window->unreg_state = OP_FAILED;
+	wake_up(&window->unregwq);
+	mutex_unlock(&ep->rma_info.rma_lock);
+}
+
+int __scif_pin_pages(void *addr, size_t len, int *out_prot,
+		     int map_flags, scif_pinned_pages_t *pages)
+{
+	struct scif_pinned_pages *pinned_pages;
+	int nr_pages, err = 0, i;
+	bool vmalloc_addr = false;
+	bool try_upgrade = false;
+	int prot = *out_prot;
+	int ulimit = 0;
+	struct mm_struct *mm = NULL;
+
+	/* Unsupported flags */
+	if (map_flags & ~(SCIF_MAP_KERNEL | SCIF_MAP_ULIMIT))
+		return -EINVAL;
+	ulimit = !!(map_flags & SCIF_MAP_ULIMIT);
+
+	/* Unsupported protection requested */
+	if (prot & ~(SCIF_PROT_READ | SCIF_PROT_WRITE))
+		return -EINVAL;
+
+	/* addr/len must be page aligned. len should be non zero */
+	if (!len ||
+	    (ALIGN((u64)addr, PAGE_SIZE) != (u64)addr) ||
+	    (ALIGN((u64)len, PAGE_SIZE) != (u64)len))
+		return -EINVAL;
+
+	might_sleep();
+
+	nr_pages = len >> PAGE_SHIFT;
+
+	/* Allocate a set of pinned pages */
+	pinned_pages = scif_create_pinned_pages(nr_pages, prot);
+	if (!pinned_pages)
+		return -ENOMEM;
+
+	if (map_flags & SCIF_MAP_KERNEL) {
+		if (is_vmalloc_addr(addr))
+			vmalloc_addr = true;
+
+		for (i = 0; i < nr_pages; i++) {
+			if (vmalloc_addr)
+				pinned_pages->pages[i] =
+					vmalloc_to_page(addr + (i * PAGE_SIZE));
+			else
+				pinned_pages->pages[i] =
+					virt_to_page(addr + (i * PAGE_SIZE));
+		}
+		pinned_pages->nr_pages = nr_pages;
+		pinned_pages->map_flags = SCIF_MAP_KERNEL;
+	} else {
+		/*
+		 * SCIF supports registration caching. If a registration has
+		 * been requested with read only permissions, then we try
+		 * to pin the pages with RW permissions so that a subsequent
+		 * transfer with RW permission can hit the cache instead of
+		 * invalidating it. If the upgrade fails with RW then we
+		 * revert back to R permission and retry
+		 */
+		if (prot == SCIF_PROT_READ)
+			try_upgrade = true;
+		prot |= SCIF_PROT_WRITE;
+retry:
+		mm = current->mm;
+		down_write(&mm->mmap_sem);
+		if (ulimit) {
+			err = __scif_check_inc_pinned_vm(mm, nr_pages);
+			if (err) {
+				up_write(&mm->mmap_sem);
+				pinned_pages->nr_pages = 0;
+				goto error_unmap;
+			}
+		}
+
+		pinned_pages->nr_pages = get_user_pages(
+				(u64)addr,
+				nr_pages,
+				(prot & SCIF_PROT_WRITE) ? FOLL_WRITE : 0,
+				pinned_pages->pages,
+				NULL);
+		up_write(&mm->mmap_sem);
+		if (nr_pages != pinned_pages->nr_pages) {
+			if (pinned_pages->nr_pages < 0)
+				pinned_pages->nr_pages = 0;
+			if (try_upgrade) {
+				if (ulimit)
+					__scif_dec_pinned_vm_lock(mm,
+								  nr_pages, 0);
+				/* Roll back any pinned pages */
+				for (i = 0; i < pinned_pages->nr_pages; i++) {
+					if (pinned_pages->pages[i])
+						put_page(
+						pinned_pages->pages[i]);
+				}
+				prot &= ~SCIF_PROT_WRITE;
+				try_upgrade = false;
+				goto retry;
+			}
+		}
+		pinned_pages->map_flags = 0;
+	}
+
+	if (pinned_pages->nr_pages < nr_pages) {
+		err = -EFAULT;
+		goto dec_pinned;
+	}
+
+	*out_prot = prot;
+	atomic_set(&pinned_pages->ref_count, 1);
+	*pages = pinned_pages;
+	return err;
+dec_pinned:
+	if (ulimit)
+		__scif_dec_pinned_vm_lock(mm, nr_pages, 0);
+	/* Something went wrong! Rollback */
+error_unmap:
+	scif_destroy_pinned_pages(pinned_pages);
+	*pages = NULL;
+	dev_dbg(scif_info.mdev.this_device,
+		"%s %d err %d len 0x%lx\n", __func__, __LINE__, err, len);
+	return err;
+}
+
+int scif_pin_pages(void *addr, size_t len, int prot,
+		   int map_flags, scif_pinned_pages_t *pages)
+{
+	return __scif_pin_pages(addr, len, &prot, map_flags, pages);
+}
+EXPORT_SYMBOL_GPL(scif_pin_pages);
+
+int scif_unpin_pages(scif_pinned_pages_t pinned_pages)
+{
+	int err = 0, ret;
+
+	if (!pinned_pages || SCIFEP_MAGIC != pinned_pages->magic)
+		return -EINVAL;
+
+	ret = atomic_sub_return(1, &pinned_pages->ref_count);
+	if (ret < 0) {
+		dev_err(scif_info.mdev.this_device,
+			"%s %d scif_unpin_pages called without pinning? rc %d\n",
+			__func__, __LINE__, ret);
+		return -EINVAL;
+	}
+	/*
+	 * Destroy the window if the ref count for this set of pinned
+	 * pages has dropped to zero. If it is positive then there is
+	 * a valid registered window which is backed by these pages and
+	 * it will be destroyed once all such windows are unregistered.
+	 */
+	if (!ret)
+		err = scif_destroy_pinned_pages(pinned_pages);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(scif_unpin_pages);
+
+static inline void
+scif_insert_local_window(struct scif_window *window, struct scif_endpt *ep)
+{
+	mutex_lock(&ep->rma_info.rma_lock);
+	scif_insert_window(window, &ep->rma_info.reg_list);
+	mutex_unlock(&ep->rma_info.rma_lock);
+}
+
+off_t scif_register_pinned_pages(scif_epd_t epd,
+				 scif_pinned_pages_t pinned_pages,
+				 off_t offset, int map_flags)
+{
+	struct scif_endpt *ep = (struct scif_endpt *)epd;
+	s64 computed_offset;
+	struct scif_window *window;
+	int err;
+	size_t len;
+	struct device *spdev;
+
+	/* Unsupported flags */
+	if (map_flags & ~SCIF_MAP_FIXED)
+		return -EINVAL;
+
+	len = pinned_pages->nr_pages << PAGE_SHIFT;
+
+	/*
+	 * Offset is not page aligned/negative or offset+len
+	 * wraps around with SCIF_MAP_FIXED.
+	 */
+	if ((map_flags & SCIF_MAP_FIXED) &&
+	    ((ALIGN(offset, PAGE_SIZE) != offset) ||
+	    (offset < 0) ||
+	    (len > LONG_MAX - offset)))
+		return -EINVAL;
+
+	might_sleep();
+
+	err = scif_verify_epd(ep);
+	if (err)
+		return err;
+	/*
+	 * It is an error to pass pinned_pages to scif_register_pinned_pages()
+	 * after calling scif_unpin_pages().
+	 */
+	if (!atomic_add_unless(&pinned_pages->ref_count, 1, 0))
+		return -EINVAL;
+
+	/* Compute the offset for this registration */
+	err = scif_get_window_offset(ep, map_flags, offset,
+				     len, &computed_offset);
+	if (err) {
+		atomic_sub(1, &pinned_pages->ref_count);
+		return err;
+	}
+
+	/* Allocate and prepare self registration window */
+	window = scif_create_window(ep, pinned_pages->nr_pages,
+				    computed_offset, false);
+	if (!window) {
+		atomic_sub(1, &pinned_pages->ref_count);
+		scif_free_window_offset(ep, NULL, computed_offset);
+		return -ENOMEM;
+	}
+
+	window->pinned_pages = pinned_pages;
+	window->nr_pages = pinned_pages->nr_pages;
+	window->prot = pinned_pages->prot;
+
+	spdev = scif_get_peer_dev(ep->remote_dev);
+	if (IS_ERR(spdev)) {
+		err = PTR_ERR(spdev);
+		scif_destroy_window(ep, window);
+		return err;
+	}
+	err = scif_send_alloc_request(ep, window);
+	if (err) {
+		dev_err(&ep->remote_dev->sdev->dev,
+			"%s %d err %d\n", __func__, __LINE__, err);
+		goto error_unmap;
+	}
+
+	/* Prepare the remote registration window */
+	err = scif_prep_remote_window(ep, window);
+	if (err) {
+		dev_err(&ep->remote_dev->sdev->dev,
+			"%s %d err %d\n", __func__, __LINE__, err);
+		goto error_unmap;
+	}
+
+	/* Tell the peer about the new window */
+	err = scif_send_scif_register(ep, window);
+	if (err) {
+		dev_err(&ep->remote_dev->sdev->dev,
+			"%s %d err %d\n", __func__, __LINE__, err);
+		goto error_unmap;
+	}
+
+	scif_put_peer_dev(spdev);
+	/* No further failures expected. Insert new window */
+	scif_insert_local_window(window, ep);
+	return computed_offset;
+error_unmap:
+	scif_destroy_window(ep, window);
+	scif_put_peer_dev(spdev);
+	dev_err(&ep->remote_dev->sdev->dev,
+		"%s %d err %d\n", __func__, __LINE__, err);
+	return err;
+}
+EXPORT_SYMBOL_GPL(scif_register_pinned_pages);
+
+off_t scif_register(scif_epd_t epd, void *addr, size_t len, off_t offset,
+		    int prot, int map_flags)
+{
+	scif_pinned_pages_t pinned_pages;
+	off_t err;
+	struct scif_endpt *ep = (struct scif_endpt *)epd;
+	s64 computed_offset;
+	struct scif_window *window;
+	struct mm_struct *mm = NULL;
+	struct device *spdev;
+
+	dev_dbg(scif_info.mdev.this_device,
+		"SCIFAPI register: ep %p addr %p len 0x%lx offset 0x%lx prot 0x%x map_flags 0x%x\n",
+		epd, addr, len, offset, prot, map_flags);
+	/* Unsupported flags */
+	if (map_flags & ~(SCIF_MAP_FIXED | SCIF_MAP_KERNEL))
+		return -EINVAL;
+
+	/*
+	 * Offset is not page aligned/negative or offset+len
+	 * wraps around with SCIF_MAP_FIXED.
+	 */
+	if ((map_flags & SCIF_MAP_FIXED) &&
+	    ((ALIGN(offset, PAGE_SIZE) != offset) ||
+	    (offset < 0) ||
+	    (len > LONG_MAX - offset)))
+		return -EINVAL;
+
+	/* Unsupported protection requested */
+	if (prot & ~(SCIF_PROT_READ | SCIF_PROT_WRITE))
+		return -EINVAL;
+
+	/* addr/len must be page aligned. len should be non zero */
+	if (!len || (ALIGN((u64)addr, PAGE_SIZE) != (u64)addr) ||
+	    (ALIGN(len, PAGE_SIZE) != len))
+		return -EINVAL;
+
+	might_sleep();
+
+	err = scif_verify_epd(ep);
+	if (err)
+		return err;
+
+	/* Compute the offset for this registration */
+	err = scif_get_window_offset(ep, map_flags, offset,
+				     len >> PAGE_SHIFT, &computed_offset);
+	if (err)
+		return err;
+
+	spdev = scif_get_peer_dev(ep->remote_dev);
+	if (IS_ERR(spdev)) {
+		err = PTR_ERR(spdev);
+		scif_free_window_offset(ep, NULL, computed_offset);
+		return err;
+	}
+	/* Allocate and prepare self registration window */
+	window = scif_create_window(ep, len >> PAGE_SHIFT,
+				    computed_offset, false);
+	if (!window) {
+		scif_free_window_offset(ep, NULL, computed_offset);
+		scif_put_peer_dev(spdev);
+		return -ENOMEM;
+	}
+
+	window->nr_pages = len >> PAGE_SHIFT;
+
+	err = scif_send_alloc_request(ep, window);
+	if (err) {
+		scif_destroy_incomplete_window(ep, window);
+		scif_put_peer_dev(spdev);
+		return err;
+	}
+
+	if (!(map_flags & SCIF_MAP_KERNEL)) {
+		mm = __scif_acquire_mm();
+		map_flags |= SCIF_MAP_ULIMIT;
+	}
+	/* Pin down the pages */
+	err = __scif_pin_pages(addr, len, &prot,
+			       map_flags & (SCIF_MAP_KERNEL | SCIF_MAP_ULIMIT),
+			       &pinned_pages);
+	if (err) {
+		scif_destroy_incomplete_window(ep, window);
+		__scif_release_mm(mm);
+		goto error;
+	}
+
+	window->pinned_pages = pinned_pages;
+	window->prot = pinned_pages->prot;
+	window->mm = mm;
+
+	/* Prepare the remote registration window */
+	err = scif_prep_remote_window(ep, window);
+	if (err) {
+		dev_err(&ep->remote_dev->sdev->dev,
+			"%s %d err %ld\n", __func__, __LINE__, err);
+		goto error_unmap;
+	}
+
+	/* Tell the peer about the new window */
+	err = scif_send_scif_register(ep, window);
+	if (err) {
+		dev_err(&ep->remote_dev->sdev->dev,
+			"%s %d err %ld\n", __func__, __LINE__, err);
+		goto error_unmap;
+	}
+
+	scif_put_peer_dev(spdev);
+	/* No further failures expected. Insert new window */
+	scif_insert_local_window(window, ep);
+	dev_dbg(&ep->remote_dev->sdev->dev,
+		"SCIFAPI register: ep %p addr %p len 0x%lx computed_offset 0x%llx\n",
+		epd, addr, len, computed_offset);
+	return computed_offset;
+error_unmap:
+	scif_destroy_window(ep, window);
+error:
+	scif_put_peer_dev(spdev);
+	dev_err(&ep->remote_dev->sdev->dev,
+		"%s %d err %ld\n", __func__, __LINE__, err);
+	return err;
+}
+EXPORT_SYMBOL_GPL(scif_register);
+
+int
+scif_unregister(scif_epd_t epd, off_t offset, size_t len)
+{
+	struct scif_endpt *ep = (struct scif_endpt *)epd;
+	struct scif_window *window = NULL;
+	struct scif_rma_req req;
+	int nr_pages, err;
+	struct device *spdev;
+
+	dev_dbg(scif_info.mdev.this_device,
+		"SCIFAPI unregister: ep %p offset 0x%lx len 0x%lx\n",
+		ep, offset, len);
+	/* len must be page aligned. len should be non zero */
+	if (!len ||
+	    (ALIGN((u64)len, PAGE_SIZE) != (u64)len))
+		return -EINVAL;
+
+	/* Offset is not page aligned or offset+len wraps around */
+	if ((ALIGN(offset, PAGE_SIZE) != offset) ||
+	    (offset < 0) ||
+	    (len > LONG_MAX - offset))
+		return -EINVAL;
+
+	err = scif_verify_epd(ep);
+	if (err)
+		return err;
+
+	might_sleep();
+	nr_pages = len >> PAGE_SHIFT;
+
+	req.out_window = &window;
+	req.offset = offset;
+	req.prot = 0;
+	req.nr_bytes = len;
+	req.type = SCIF_WINDOW_FULL;
+	req.head = &ep->rma_info.reg_list;
+
+	spdev = scif_get_peer_dev(ep->remote_dev);
+	if (IS_ERR(spdev)) {
+		err = PTR_ERR(spdev);
+		return err;
+	}
+	mutex_lock(&ep->rma_info.rma_lock);
+	/* Does a valid window exist? */
+	err = scif_query_window(&req);
+	if (err) {
+		dev_err(&ep->remote_dev->sdev->dev,
+			"%s %d err %d\n", __func__, __LINE__, err);
+		goto error;
+	}
+	/* Unregister all the windows in this range */
+	err = scif_rma_list_unregister(window, offset, nr_pages);
+	if (err)
+		dev_err(&ep->remote_dev->sdev->dev,
+			"%s %d err %d\n", __func__, __LINE__, err);
+error:
+	mutex_unlock(&ep->rma_info.rma_lock);
+	scif_put_peer_dev(spdev);
+	return err;
+}
+EXPORT_SYMBOL_GPL(scif_unregister);