These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / drivers / misc / mic / scif / scif_rma.c
diff --git a/kernel/drivers/misc/mic/scif/scif_rma.c b/kernel/drivers/misc/mic/scif/scif_rma.c
new file mode 100644 (file)
index 0000000..8310b4d
--- /dev/null
@@ -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 "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,
+                        SCIF_DMA_64BIT_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_dma_phys ?
+                                   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(
+                               current,
+                               mm,
+                               (u64)addr,
+                               nr_pages,
+                               !!(prot & SCIF_PROT_WRITE),
+                               0,
+                               pinned_pages->pages,
+                               NULL);
+               up_write(&mm->mmap_sem);
+               if (nr_pages != pinned_pages->nr_pages) {
+                       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;
+               pinned_pages->nr_pages = nr_pages;
+               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:
+       pinned_pages->nr_pages = nr_pages;
+       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) ||
+           (offset + (off_t)len < 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) ||
+           (offset + (off_t)len < 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 + (off_t)len < 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);