1 /******************************************************************************
5 * Granting foreign access to our memory reservation.
7 * Copyright (c) 2005-2006, Christopher Clark
8 * Copyright (c) 2004-2005, K A Fraser
9 * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
10 * VA Linux Systems Japan. Split out x86 specific part.
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License version 2
14 * as published by the Free Software Foundation; or, when distributed
15 * separately from the Linux kernel or incorporated into other
16 * software packages, subject to the following license:
18 * Permission is hereby granted, free of charge, to any person obtaining a copy
19 * of this source file (the "Software"), to deal in the Software without
20 * restriction, including without limitation the rights to use, copy, modify,
21 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
22 * and to permit persons to whom the Software is furnished to do so, subject to
23 * the following conditions:
25 * The above copyright notice and this permission notice shall be included in
26 * all copies or substantial portions of the Software.
28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
29 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
30 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
31 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
32 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
33 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
37 #include <linux/sched.h>
39 #include <linux/slab.h>
40 #include <linux/vmalloc.h>
42 #include <xen/interface/xen.h>
44 #include <xen/grant_table.h>
47 #include <asm/pgtable.h>
49 static struct gnttab_vm_area {
50 struct vm_struct *area;
52 } gnttab_shared_vm_area, gnttab_status_vm_area;
54 int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
55 unsigned long max_nr_gframes,
58 void *shared = *__shared;
63 *__shared = shared = gnttab_shared_vm_area.area->addr;
65 addr = (unsigned long)shared;
67 for (i = 0; i < nr_gframes; i++) {
68 set_pte_at(&init_mm, addr, gnttab_shared_vm_area.ptes[i],
69 mfn_pte(frames[i], PAGE_KERNEL));
76 int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
77 unsigned long max_nr_gframes,
78 grant_status_t **__shared)
80 grant_status_t *shared = *__shared;
85 *__shared = shared = gnttab_status_vm_area.area->addr;
87 addr = (unsigned long)shared;
89 for (i = 0; i < nr_gframes; i++) {
90 set_pte_at(&init_mm, addr, gnttab_status_vm_area.ptes[i],
91 mfn_pte(frames[i], PAGE_KERNEL));
98 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
104 if (shared == gnttab_status_vm_area.area->addr)
105 ptes = gnttab_status_vm_area.ptes;
107 ptes = gnttab_shared_vm_area.ptes;
109 addr = (unsigned long)shared;
111 for (i = 0; i < nr_gframes; i++) {
112 set_pte_at(&init_mm, addr, ptes[i], __pte(0));
117 static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames)
119 area->ptes = kmalloc(sizeof(pte_t *) * nr_frames, GFP_KERNEL);
120 if (area->ptes == NULL)
123 area->area = alloc_vm_area(PAGE_SIZE * nr_frames, area->ptes);
124 if (area->area == NULL) {
132 static void arch_gnttab_vfree(struct gnttab_vm_area *area)
134 free_vm_area(area->area);
138 int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status)
142 if (!xen_pv_domain())
145 ret = arch_gnttab_valloc(&gnttab_shared_vm_area, nr_shared);
150 * Always allocate the space for the status frames in case
151 * we're migrated to a host with V2 support.
153 ret = arch_gnttab_valloc(&gnttab_status_vm_area, nr_status);
159 arch_gnttab_vfree(&gnttab_shared_vm_area);
163 #ifdef CONFIG_XEN_PVH
164 #include <xen/balloon.h>
165 #include <xen/events.h>
166 #include <linux/slab.h>
167 static int __init xlated_setup_gnttab_pages(void)
173 unsigned long nr_grant_frames = gnttab_max_grant_frames();
175 BUG_ON(nr_grant_frames == 0);
176 pages = kcalloc(nr_grant_frames, sizeof(pages[0]), GFP_KERNEL);
180 pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL);
185 rc = alloc_xenballooned_pages(nr_grant_frames, pages, 0 /* lowmem */);
187 pr_warn("%s Couldn't balloon alloc %ld pfns rc:%d\n", __func__,
188 nr_grant_frames, rc);
193 for (i = 0; i < nr_grant_frames; i++)
194 pfns[i] = page_to_pfn(pages[i]);
196 rc = arch_gnttab_map_shared(pfns, nr_grant_frames, nr_grant_frames,
197 &xen_auto_xlat_grant_frames.vaddr);
200 pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__,
201 nr_grant_frames, rc);
202 free_xenballooned_pages(nr_grant_frames, pages);
209 xen_auto_xlat_grant_frames.pfn = pfns;
210 xen_auto_xlat_grant_frames.count = nr_grant_frames;
215 static int __init xen_pvh_gnttab_setup(void)
217 if (!xen_pvh_domain())
220 return xlated_setup_gnttab_pages();
222 /* Call it _before_ __gnttab_init as we need to initialize the
223 * xen_auto_xlat_grant_frames first. */
224 core_initcall(xen_pvh_gnttab_setup);