1 files changed, 291 insertions, 0 deletions
diff --git a/drivers/misc/mic/scif/scif_rma_list.c b/drivers/misc/mic/scif/scif_rma_list.c
new file mode 100644
index 000000000000..e1ef8daedd5a
--- /dev/null
+++ b/drivers/misc/mic/scif/scif_rma_list.c
@@ -0,0 +1,291 @@
+/*
+ * 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 "scif_main.h"
+#include <linux/mmu_notifier.h>
+#include <linux/highmem.h>
+
+/*
+ * scif_insert_tcw:
+ *
+ * Insert a temp window to the temp registration list sorted by va_for_temp.
+ * RMA lock must be held.
+ */
+void scif_insert_tcw(struct scif_window *window, struct list_head *head)
+{
+	struct scif_window *curr = NULL;
+	struct scif_window *prev = list_entry(head, struct scif_window, list);
+	struct list_head *item;
+
+	INIT_LIST_HEAD(&window->list);
+	/* Compare with tail and if the entry is new tail add it to the end */
+	if (!list_empty(head)) {
+		curr = list_entry(head->prev, struct scif_window, list);
+		if (curr->va_for_temp < window->va_for_temp) {
+			list_add_tail(&window->list, head);
+			return;
+		}
+	}
+	list_for_each(item, head) {
+		curr = list_entry(item, struct scif_window, list);
+		if (curr->va_for_temp > window->va_for_temp)
+			break;
+		prev = curr;
+	}
+	list_add(&window->list, &prev->list);
+}
+
+/*
+ * scif_insert_window:
+ *
+ * Insert a window to the self registration list sorted by offset.
+ * RMA lock must be held.
+ */
+void scif_insert_window(struct scif_window *window, struct list_head *head)
+{
+	struct scif_window *curr = NULL, *prev = NULL;
+	struct list_head *item;
+
+	INIT_LIST_HEAD(&window->list);
+	list_for_each(item, head) {
+		curr = list_entry(item, struct scif_window, list);
+		if (curr->offset > window->offset)
+			break;
+		prev = curr;
+	}
+	if (!prev)
+		list_add(&window->list, head);
+	else
+		list_add(&window->list, &prev->list);
+	scif_set_window_ref(window, window->nr_pages);
+}
+
+/*
+ * scif_query_tcw:
+ *
+ * Query the temp cached registration list of ep for an overlapping window
+ * in case of permission mismatch, destroy the previous window. if permissions
+ * match and overlap is partial, destroy the window but return the new range
+ * RMA lock must be held.
+ */
+int scif_query_tcw(struct scif_endpt *ep, struct scif_rma_req *req)
+{
+	struct list_head *item, *temp, *head = req->head;
+	struct scif_window *window;
+	u64 start_va_window, start_va_req = req->va_for_temp;
+	u64 end_va_window, end_va_req = start_va_req + req->nr_bytes;
+
+	if (!req->nr_bytes)
+		return -EINVAL;
+	/*
+	 * Avoid traversing the entire list to find out that there
+	 * is no entry that matches
+	 */
+	if (!list_empty(head)) {
+		window = list_last_entry(head, struct scif_window, list);
+		end_va_window = window->va_for_temp +
+			(window->nr_pages << PAGE_SHIFT);
+		if (start_va_req > end_va_window)
+			return -ENXIO;
+	}
+	list_for_each_safe(item, temp, head) {
+		window = list_entry(item, struct scif_window, list);
+		start_va_window = window->va_for_temp;
+		end_va_window = window->va_for_temp +
+			(window->nr_pages << PAGE_SHIFT);
+		if (start_va_req < start_va_window &&
+		    end_va_req < start_va_window)
+			break;
+		if (start_va_req >= end_va_window)
+			continue;
+		if ((window->prot & req->prot) == req->prot) {
+			if (start_va_req >= start_va_window &&
+			    end_va_req <= end_va_window) {
+				*req->out_window = window;
+				return 0;
+			}
+			/* expand window */
+			if (start_va_req < start_va_window) {
+				req->nr_bytes +=
+					start_va_window - start_va_req;
+				req->va_for_temp = start_va_window;
+			}
+			if (end_va_req >= end_va_window)
+				req->nr_bytes += end_va_window - end_va_req;
+		}
+		/* Destroy the old window to create a new one */
+		__scif_rma_destroy_tcw_helper(window);
+		break;
+	}
+	return -ENXIO;
+}
+
+/*
+ * scif_query_window:
+ *
+ * Query the registration list and check if a valid contiguous
+ * range of windows exist.
+ * RMA lock must be held.
+ */
+int scif_query_window(struct scif_rma_req *req)
+{
+	struct list_head *item;
+	struct scif_window *window;
+	s64 end_offset, offset = req->offset;
+	u64 tmp_min, nr_bytes_left = req->nr_bytes;
+
+	if (!req->nr_bytes)
+		return -EINVAL;
+
+	list_for_each(item, req->head) {
+		window = list_entry(item, struct scif_window, list);
+		end_offset = window->offset +
+			(window->nr_pages << PAGE_SHIFT);
+		if (offset < window->offset)
+			/* Offset not found! */
+			return -ENXIO;
+		if (offset >= end_offset)
+			continue;
+		/* Check read/write protections. */
+		if ((window->prot & req->prot) != req->prot)
+			return -EPERM;
+		if (nr_bytes_left == req->nr_bytes)
+			/* Store the first window */
+			*req->out_window = window;
+		tmp_min = min((u64)end_offset - offset, nr_bytes_left);
+		nr_bytes_left -= tmp_min;
+		offset += tmp_min;
+		/*
+		 * Range requested encompasses
+		 * multiple windows contiguously.
+		 */
+		if (!nr_bytes_left) {
+			/* Done for partial window */
+			if (req->type == SCIF_WINDOW_PARTIAL ||
+			    req->type == SCIF_WINDOW_SINGLE)
+				return 0;
+			/* Extra logic for full windows */
+			if (offset == end_offset)
+				/* Spanning multiple whole windows */
+				return 0;
+				/* Not spanning multiple whole windows */
+			return -ENXIO;
+		}
+		if (req->type == SCIF_WINDOW_SINGLE)
+			break;
+	}
+	dev_err(scif_info.mdev.this_device,
+		"%s %d ENXIO\n", __func__, __LINE__);
+	return -ENXIO;
+}
+
+/*
+ * scif_rma_list_unregister:
+ *
+ * Traverse the self registration list starting from window:
+ * 1) Call scif_unregister_window(..)
+ * RMA lock must be held.
+ */
+int scif_rma_list_unregister(struct scif_window *window,
+			     s64 offset, int nr_pages)
+{
+	struct scif_endpt *ep = (struct scif_endpt *)window->ep;
+	struct list_head *head = &ep->rma_info.reg_list;
+	s64 end_offset;
+	int err = 0;
+	int loop_nr_pages;
+	struct scif_window *_window;
+
+	list_for_each_entry_safe_from(window, _window, head, list) {
+		end_offset = window->offset + (window->nr_pages << PAGE_SHIFT);
+		loop_nr_pages = min((int)((end_offset - offset) >> PAGE_SHIFT),
+				    nr_pages);
+		err = scif_unregister_window(window);
+		if (err)
+			return err;
+		nr_pages -= loop_nr_pages;
+		offset += (loop_nr_pages << PAGE_SHIFT);
+		if (!nr_pages)
+			break;
+	}
+	return 0;
+}
+
+/*
+ * scif_unmap_all_window:
+ *
+ * Traverse all the windows in the self registration list and:
+ * 1) Delete any DMA mappings created
+ */
+void scif_unmap_all_windows(scif_epd_t epd)
+{
+	struct list_head *item, *tmp;
+	struct scif_window *window;
+	struct scif_endpt *ep = (struct scif_endpt *)epd;
+	struct list_head *head = &ep->rma_info.reg_list;
+
+	mutex_lock(&ep->rma_info.rma_lock);
+	list_for_each_safe(item, tmp, head) {
+		window = list_entry(item, struct scif_window, list);
+		scif_unmap_window(ep->remote_dev, window);
+	}
+	mutex_unlock(&ep->rma_info.rma_lock);
+}
+
+/*
+ * scif_unregister_all_window:
+ *
+ * Traverse all the windows in the self registration list and:
+ * 1) Call scif_unregister_window(..)
+ * RMA lock must be held.
+ */
+int scif_unregister_all_windows(scif_epd_t epd)
+{
+	struct list_head *item, *tmp;
+	struct scif_window *window;
+	struct scif_endpt *ep = (struct scif_endpt *)epd;
+	struct list_head *head = &ep->rma_info.reg_list;
+	int err = 0;
+
+	mutex_lock(&ep->rma_info.rma_lock);
+retry:
+	item = NULL;
+	tmp = NULL;
+	list_for_each_safe(item, tmp, head) {
+		window = list_entry(item, struct scif_window, list);
+		ep->rma_info.async_list_del = 0;
+		err = scif_unregister_window(window);
+		if (err)
+			dev_err(scif_info.mdev.this_device,
+				"%s %d err %d\n",
+				__func__, __LINE__, err);
+		/*
+		 * Need to restart list traversal if there has been
+		 * an asynchronous list entry deletion.
+		 */
+		if (ACCESS_ONCE(ep->rma_info.async_list_del))
+			goto retry;
+	}
+	mutex_unlock(&ep->rma_info.rma_lock);
+	if (!list_empty(&ep->rma_info.mmn_list)) {
+		spin_lock(&scif_info.rmalock);
+		list_add_tail(&ep->mmu_list, &scif_info.mmu_notif_cleanup);
+		spin_unlock(&scif_info.rmalock);
+		schedule_work(&scif_info.mmu_notif_work);
+	}
+	return err;
+}