--- /dev/null
+/*
+ * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
+ * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/mm.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+
+#include "ipath_kernel.h"
+
+static void __ipath_release_user_pages(struct page **p, size_t num_pages,
+ int dirty)
+{
+ size_t i;
+
+ for (i = 0; i < num_pages; i++) {
+ ipath_cdbg(MM, "%lu/%lu put_page %p\n", (unsigned long) i,
+ (unsigned long) num_pages, p[i]);
+ if (dirty)
+ set_page_dirty_lock(p[i]);
+ put_page(p[i]);
+ }
+}
+
+/* call with current->mm->mmap_sem held */
+static int __ipath_get_user_pages(unsigned long start_page, size_t num_pages,
+ struct page **p)
+{
+ unsigned long lock_limit;
+ size_t got;
+ int ret;
+
+ lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+
+ if (num_pages > lock_limit) {
+ ret = -ENOMEM;
+ goto bail;
+ }
+
+ ipath_cdbg(VERBOSE, "pin %lx pages from vaddr %lx\n",
+ (unsigned long) num_pages, start_page);
+
+ for (got = 0; got < num_pages; got += ret) {
+ ret = get_user_pages(current, current->mm,
+ start_page + got * PAGE_SIZE,
+ num_pages - got, 1, 1,
+ p + got, NULL);
+ if (ret < 0)
+ goto bail_release;
+ }
+
+ current->mm->pinned_vm += num_pages;
+
+ ret = 0;
+ goto bail;
+
+bail_release:
+ __ipath_release_user_pages(p, got, 0);
+bail:
+ return ret;
+}
+
+/**
+ * ipath_map_page - a safety wrapper around pci_map_page()
+ *
+ * A dma_addr of all 0's is interpreted by the chip as "disabled".
+ * Unfortunately, it can also be a valid dma_addr returned on some
+ * architectures.
+ *
+ * The powerpc iommu assigns dma_addrs in ascending order, so we don't
+ * have to bother with retries or mapping a dummy page to insure we
+ * don't just get the same mapping again.
+ *
+ * I'm sure we won't be so lucky with other iommu's, so FIXME.
+ */
+dma_addr_t ipath_map_page(struct pci_dev *hwdev, struct page *page,
+ unsigned long offset, size_t size, int direction)
+{
+ dma_addr_t phys;
+
+ phys = pci_map_page(hwdev, page, offset, size, direction);
+
+ if (phys == 0) {
+ pci_unmap_page(hwdev, phys, size, direction);
+ phys = pci_map_page(hwdev, page, offset, size, direction);
+ /*
+ * FIXME: If we get 0 again, we should keep this page,
+ * map another, then free the 0 page.
+ */
+ }
+
+ return phys;
+}
+
+/**
+ * ipath_map_single - a safety wrapper around pci_map_single()
+ *
+ * Same idea as ipath_map_page().
+ */
+dma_addr_t ipath_map_single(struct pci_dev *hwdev, void *ptr, size_t size,
+ int direction)
+{
+ dma_addr_t phys;
+
+ phys = pci_map_single(hwdev, ptr, size, direction);
+
+ if (phys == 0) {
+ pci_unmap_single(hwdev, phys, size, direction);
+ phys = pci_map_single(hwdev, ptr, size, direction);
+ /*
+ * FIXME: If we get 0 again, we should keep this page,
+ * map another, then free the 0 page.
+ */
+ }
+
+ return phys;
+}
+
+/**
+ * ipath_get_user_pages - lock user pages into memory
+ * @start_page: the start page
+ * @num_pages: the number of pages
+ * @p: the output page structures
+ *
+ * This function takes a given start page (page aligned user virtual
+ * address) and pins it and the following specified number of pages. For
+ * now, num_pages is always 1, but that will probably change at some point
+ * (because caller is doing expected sends on a single virtually contiguous
+ * buffer, so we can do all pages at once).
+ */
+int ipath_get_user_pages(unsigned long start_page, size_t num_pages,
+ struct page **p)
+{
+ int ret;
+
+ down_write(¤t->mm->mmap_sem);
+
+ ret = __ipath_get_user_pages(start_page, num_pages, p);
+
+ up_write(¤t->mm->mmap_sem);
+
+ return ret;
+}
+
+void ipath_release_user_pages(struct page **p, size_t num_pages)
+{
+ down_write(¤t->mm->mmap_sem);
+
+ __ipath_release_user_pages(p, num_pages, 1);
+
+ current->mm->pinned_vm -= num_pages;
+
+ up_write(¤t->mm->mmap_sem);
+}
+
+struct ipath_user_pages_work {
+ struct work_struct work;
+ struct mm_struct *mm;
+ unsigned long num_pages;
+};
+
+static void user_pages_account(struct work_struct *_work)
+{
+ struct ipath_user_pages_work *work =
+ container_of(_work, struct ipath_user_pages_work, work);
+
+ down_write(&work->mm->mmap_sem);
+ work->mm->pinned_vm -= work->num_pages;
+ up_write(&work->mm->mmap_sem);
+ mmput(work->mm);
+ kfree(work);
+}
+
+void ipath_release_user_pages_on_close(struct page **p, size_t num_pages)
+{
+ struct ipath_user_pages_work *work;
+ struct mm_struct *mm;
+
+ __ipath_release_user_pages(p, num_pages, 1);
+
+ mm = get_task_mm(current);
+ if (!mm)
+ return;
+
+ work = kmalloc(sizeof(*work), GFP_KERNEL);
+ if (!work)
+ goto bail_mm;
+
+ INIT_WORK(&work->work, user_pages_account);
+ work->mm = mm;
+ work->num_pages = num_pages;
+
+ queue_work(ib_wq, &work->work);
+ return;
+
+bail_mm:
+ mmput(mm);
+ return;
+}
Code Review / kvmfornfv.git / blobdiff