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-rw-r--r--arch/x86/xen/grant-table.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c
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+++ b/arch/x86/xen/grant-table.c
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+/******************************************************************************
+ * grant_table.c
+ * x86 specific part
+ *
+ * Granting foreign access to our memory reservation.
+ *
+ * Copyright (c) 2005-2006, Christopher Clark
+ * Copyright (c) 2004-2005, K A Fraser
+ * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
+ * VA Linux Systems Japan. Split out x86 specific part.
+ *
+ * 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; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * 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/sched.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+
+#include <xen/interface/xen.h>
+#include <xen/page.h>
+#include <xen/grant_table.h>
+
+#include <asm/pgtable.h>
+
+static int map_pte_fn(pte_t *pte, struct page *pmd_page,
+ unsigned long addr, void *data)
+{
+ unsigned long **frames = (unsigned long **)data;
+
+ set_pte_at(&init_mm, addr, pte, mfn_pte((*frames)[0], PAGE_KERNEL));
+ (*frames)++;
+ return 0;
+}
+
+static int unmap_pte_fn(pte_t *pte, struct page *pmd_page,
+ unsigned long addr, void *data)
+{
+
+ set_pte_at(&init_mm, addr, pte, __pte(0));
+ return 0;
+}
+
+int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
+ unsigned long max_nr_gframes,
+ struct grant_entry **__shared)
+{
+ int rc;
+ struct grant_entry *shared = *__shared;
+
+ if (shared == NULL) {
+ struct vm_struct *area =
+ xen_alloc_vm_area(PAGE_SIZE * max_nr_gframes);
+ BUG_ON(area == NULL);
+ shared = area->addr;
+ *__shared = shared;
+ }
+
+ rc = apply_to_page_range(&init_mm, (unsigned long)shared,
+ PAGE_SIZE * nr_gframes,
+ map_pte_fn, &frames);
+ return rc;
+}
+
+void arch_gnttab_unmap_shared(struct grant_entry *shared,
+ unsigned long nr_gframes)
+{
+ apply_to_page_range(&init_mm, (unsigned long)shared,
+ PAGE_SIZE * nr_gframes, unmap_pte_fn, NULL);
+}