Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / infiniband / hw / qib / qib_user_pages.c

diff --git a/kernel/drivers/infiniband/hw/qib/qib_user_pages.c b/kernel/drivers/infiniband/hw/qib/qib_user_pages.c
new file mode 100644 (file)
index 0000000..74f90b2
--- /dev/null
+++ b/kernel/drivers/infiniband/hw/qib/qib_user_pages.c
@@ -0,0 +1,157 @@
+/*
+ * Copyright (c) 2006, 2007, 2008, 2009 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 "qib.h"
+
+static void __qib_release_user_pages(struct page **p, size_t num_pages,
+                                    int dirty)
+{
+       size_t i;
+
+       for (i = 0; i < num_pages; i++) {
+               if (dirty)
+                       set_page_dirty_lock(p[i]);
+               put_page(p[i]);
+       }
+}
+
+/*
+ * Call with current->mm->mmap_sem held.
+ */
+static int __qib_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 && !capable(CAP_IPC_LOCK)) {
+               ret = -ENOMEM;
+               goto bail;
+       }
+
+       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:
+       __qib_release_user_pages(p, got, 0);
+bail:
+       return ret;
+}
+
+/**
+ * qib_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 qib_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;
+}
+
+/**
+ * qib_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 qib_get_user_pages(unsigned long start_page, size_t num_pages,
+                      struct page **p)
+{
+       int ret;
+
+       down_write(&current->mm->mmap_sem);
+
+       ret = __qib_get_user_pages(start_page, num_pages, p);
+
+       up_write(&current->mm->mmap_sem);
+
+       return ret;
+}
+
+void qib_release_user_pages(struct page **p, size_t num_pages)
+{
+       if (current->mm) /* during close after signal, mm can be NULL */
+               down_write(&current->mm->mmap_sem);
+
+       __qib_release_user_pages(p, num_pages, 1);
+
+       if (current->mm) {
+               current->mm->pinned_vm -= num_pages;
+               up_write(&current->mm->mmap_sem);
+       }
+}