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 
20 struct gntdev_dmabuf_priv;
21 
22 struct gntdev_priv {
23 	/* Maps with visible offsets in the file descriptor. */
24 	struct list_head maps;
25 	/* lock protects maps and freeable_maps. */
26 	struct mutex lock;
27 
28 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
29 	/* Device for which DMA memory is allocated. */
30 	struct device *dma_dev;
31 #endif
32 
33 #ifdef CONFIG_XEN_GNTDEV_DMABUF
34 	struct gntdev_dmabuf_priv *dmabuf_priv;
35 #endif
36 };
37 
38 struct gntdev_unmap_notify {
39 	int flags;
40 	/* Address relative to the start of the gntdev_grant_map. */
41 	int addr;
42 	evtchn_port_t event;
43 };
44 
45 struct gntdev_grant_map {
46 	struct mmu_interval_notifier notifier;
47 	struct list_head next;
48 	struct vm_area_struct *vma;
49 	int index;
50 	int count;
51 	int flags;
52 	refcount_t users;
53 	struct gntdev_unmap_notify notify;
54 	struct ioctl_gntdev_grant_ref *grants;
55 	struct gnttab_map_grant_ref   *map_ops;
56 	struct gnttab_unmap_grant_ref *unmap_ops;
57 	struct gnttab_map_grant_ref   *kmap_ops;
58 	struct gnttab_unmap_grant_ref *kunmap_ops;
59 	struct page **pages;
60 	unsigned long pages_vm_start;
61 
62 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
63 	/*
64 	 * If dmabuf_vaddr is not NULL then this mapping is backed by DMA
65 	 * capable memory.
66 	 */
67 
68 	struct device *dma_dev;
69 	/* Flags used to create this DMA buffer: GNTDEV_DMA_FLAG_XXX. */
70 	int dma_flags;
71 	void *dma_vaddr;
72 	dma_addr_t dma_bus_addr;
73 	/* Needed to avoid allocation in gnttab_dma_free_pages(). */
74 	xen_pfn_t *frames;
75 #endif
76 };
77 
78 struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
79 					  int dma_flags);
80 
81 void gntdev_add_map(struct gntdev_priv *priv, struct gntdev_grant_map *add);
82 
83 void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map);
84 
85 bool gntdev_test_page_count(unsigned int count);
86 
87 int gntdev_map_grant_pages(struct gntdev_grant_map *map);
88 
89 #endif
90