1/******************************************************************************
2 * grant_table.h
3 *
4 * Two sets of functionality:
5 * 1. Granting foreign access to our memory reservation.
6 * 2. Accessing others' memory reservations via grant references.
7 * (i.e., mechanisms for both sender and recipient of grant references)
8 *
9 * Copyright (c) 2004-2005, K A Fraser
10 * Copyright (c) 2005, Christopher Clark
11 *
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:
17 *
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:
24 *
25 * The above copyright notice and this permission notice shall be included in
26 * all copies or substantial portions of the Software.
27 *
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
34 * IN THE SOFTWARE.
35 */
36
37#ifndef __ASM_GNTTAB_H__
38#define __ASM_GNTTAB_H__
39
40#include <asm/page.h>
41
42#include <xen/interface/xen.h>
43#include <xen/interface/grant_table.h>
44
45#include <asm/xen/hypervisor.h>
46
47#include <xen/features.h>
48#include <linux/mm_types.h>
49#include <linux/page-flags.h>
50
51#define GNTTAB_RESERVED_XENSTORE 1
52
53/* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
54#define NR_GRANT_FRAMES 4
55
56struct gnttab_free_callback {
57	struct gnttab_free_callback *next;
58	void (*fn)(void *);
59	void *arg;
60	u16 count;
61};
62
63struct gntab_unmap_queue_data;
64
65typedef void (*gnttab_unmap_refs_done)(int result, struct gntab_unmap_queue_data *data);
66
67struct gntab_unmap_queue_data
68{
69	struct delayed_work	gnttab_work;
70	void *data;
71	gnttab_unmap_refs_done	done;
72	struct gnttab_unmap_grant_ref *unmap_ops;
73	struct gnttab_unmap_grant_ref *kunmap_ops;
74	struct page **pages;
75	unsigned int count;
76	unsigned int age;
77};
78
79int gnttab_init(void);
80int gnttab_suspend(void);
81int gnttab_resume(void);
82
83int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
84				int readonly);
85
86/*
87 * End access through the given grant reference, iff the grant entry is no
88 * longer in use.  Return 1 if the grant entry was freed, 0 if it is still in
89 * use.
90 */
91int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
92
93/*
94 * Eventually end access through the given grant reference, and once that
95 * access has been ended, free the given page too.  Access will be ended
96 * immediately iff the grant entry is not in use, otherwise it will happen
97 * some time later.  page may be 0, in which case no freeing will occur.
98 */
99void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
100			       unsigned long page);
101
102int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
103
104unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
105unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
106
107int gnttab_query_foreign_access(grant_ref_t ref);
108
109/*
110 * operations on reserved batches of grant references
111 */
112int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head);
113
114void gnttab_free_grant_reference(grant_ref_t ref);
115
116void gnttab_free_grant_references(grant_ref_t head);
117
118int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
119
120int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
121
122void gnttab_release_grant_reference(grant_ref_t *private_head,
123				    grant_ref_t release);
124
125void gnttab_request_free_callback(struct gnttab_free_callback *callback,
126				  void (*fn)(void *), void *arg, u16 count);
127void gnttab_cancel_free_callback(struct gnttab_free_callback *callback);
128
129void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
130				     unsigned long frame, int readonly);
131
132void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
133				       unsigned long pfn);
134
135static inline void
136gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
137		  uint32_t flags, grant_ref_t ref, domid_t domid)
138{
139	if (flags & GNTMAP_contains_pte)
140		map->host_addr = addr;
141	else if (xen_feature(XENFEAT_auto_translated_physmap))
142		map->host_addr = __pa(addr);
143	else
144		map->host_addr = addr;
145
146	map->flags = flags;
147	map->ref = ref;
148	map->dom = domid;
149}
150
151static inline void
152gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr,
153		    uint32_t flags, grant_handle_t handle)
154{
155	if (flags & GNTMAP_contains_pte)
156		unmap->host_addr = addr;
157	else if (xen_feature(XENFEAT_auto_translated_physmap))
158		unmap->host_addr = __pa(addr);
159	else
160		unmap->host_addr = addr;
161
162	unmap->handle = handle;
163	unmap->dev_bus_addr = 0;
164}
165
166int arch_gnttab_init(unsigned long nr_shared);
167int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes,
168			   unsigned long max_nr_gframes,
169			   void **__shared);
170void arch_gnttab_unmap(void *shared, unsigned long nr_gframes);
171
172struct grant_frames {
173	xen_pfn_t *pfn;
174	unsigned int count;
175	void *vaddr;
176};
177extern struct grant_frames xen_auto_xlat_grant_frames;
178unsigned int gnttab_max_grant_frames(void);
179int gnttab_setup_auto_xlat_frames(phys_addr_t addr);
180void gnttab_free_auto_xlat_frames(void);
181
182#define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
183
184int gnttab_alloc_pages(int nr_pages, struct page **pages);
185void gnttab_free_pages(int nr_pages, struct page **pages);
186
187int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
188		    struct gnttab_map_grant_ref *kmap_ops,
189		    struct page **pages, unsigned int count);
190int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
191		      struct gnttab_unmap_grant_ref *kunmap_ops,
192		      struct page **pages, unsigned int count);
193void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item);
194int gnttab_unmap_refs_sync(struct gntab_unmap_queue_data *item);
195
196
197/* Perform a batch of grant map/copy operations. Retry every batch slot
198 * for which the hypervisor returns GNTST_eagain. This is typically due
199 * to paged out target frames.
200 *
201 * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds.
202 *
203 * Return value in each iand every status field of the batch guaranteed
204 * to not be GNTST_eagain.
205 */
206void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
207void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
208
209
210struct xen_page_foreign {
211	domid_t domid;
212	grant_ref_t gref;
213};
214
215static inline struct xen_page_foreign *xen_page_foreign(struct page *page)
216{
217	if (!PageForeign(page))
218		return NULL;
219#if BITS_PER_LONG < 64
220	return (struct xen_page_foreign *)page->private;
221#else
222	BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG);
223	return (struct xen_page_foreign *)&page->private;
224#endif
225}
226
227#endif /* __ASM_GNTTAB_H__ */
228