xref: /openbmc/linux/drivers/xen/gntdev-common.h (revision 2a598d0b)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 /*
4  * Common functionality of grant device.
5  *
6  * Copyright (c) 2006-2007, D G Murray.
7  *           (c) 2009 Gerd Hoffmann <kraxel@redhat.com>
8  *           (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
9  */
10 
11 #ifndef _GNTDEV_COMMON_H
12 #define _GNTDEV_COMMON_H
13 
14 #include <linux/mm.h>
15 #include <linux/mman.h>
16 #include <linux/mmu_notifier.h>
17 #include <linux/types.h>
18 #include <xen/interface/event_channel.h>
19 #include <xen/grant_table.h>
20 
21 struct gntdev_dmabuf_priv;
22 
23 struct gntdev_priv {
24 	/* Maps with visible offsets in the file descriptor. */
25 	struct list_head maps;
26 	/* lock protects maps and freeable_maps. */
27 	struct mutex lock;
28 
29 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
30 	/* Device for which DMA memory is allocated. */
31 	struct device *dma_dev;
32 #endif
33 
34 #ifdef CONFIG_XEN_GNTDEV_DMABUF
35 	struct gntdev_dmabuf_priv *dmabuf_priv;
36 #endif
37 };
38 
39 struct gntdev_unmap_notify {
40 	int flags;
41 	/* Address relative to the start of the gntdev_grant_map. */
42 	int addr;
43 	evtchn_port_t event;
44 };
45 
46 struct gntdev_grant_map {
47 	atomic_t in_use;
48 	struct mmu_interval_notifier notifier;
49 	bool notifier_init;
50 	struct list_head next;
51 	int index;
52 	int count;
53 	int flags;
54 	refcount_t users;
55 	struct gntdev_unmap_notify notify;
56 	struct ioctl_gntdev_grant_ref *grants;
57 	struct gnttab_map_grant_ref   *map_ops;
58 	struct gnttab_unmap_grant_ref *unmap_ops;
59 	struct gnttab_map_grant_ref   *kmap_ops;
60 	struct gnttab_unmap_grant_ref *kunmap_ops;
61 	bool *being_removed;
62 	struct page **pages;
63 	unsigned long pages_vm_start;
64 
65 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
66 	/*
67 	 * If dmabuf_vaddr is not NULL then this mapping is backed by DMA
68 	 * capable memory.
69 	 */
70 
71 	struct device *dma_dev;
72 	/* Flags used to create this DMA buffer: GNTDEV_DMA_FLAG_XXX. */
73 	int dma_flags;
74 	void *dma_vaddr;
75 	dma_addr_t dma_bus_addr;
76 	/* Needed to avoid allocation in gnttab_dma_free_pages(). */
77 	xen_pfn_t *frames;
78 #endif
79 
80 	/* Number of live grants */
81 	atomic_t live_grants;
82 	/* Needed to avoid allocation in __unmap_grant_pages */
83 	struct gntab_unmap_queue_data unmap_data;
84 };
85 
86 struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
87 					  int dma_flags);
88 
89 void gntdev_add_map(struct gntdev_priv *priv, struct gntdev_grant_map *add);
90 
91 void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map);
92 
93 bool gntdev_test_page_count(unsigned int count);
94 
95 int gntdev_map_grant_pages(struct gntdev_grant_map *map);
96 
97 #endif
98