xref: /openbmc/linux/drivers/xen/gntdev-common.h (revision d0e22329)
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 
19 struct gntdev_dmabuf_priv;
20 
21 struct gntdev_priv {
22 	/* Maps with visible offsets in the file descriptor. */
23 	struct list_head maps;
24 	/*
25 	 * Maps that are not visible; will be freed on munmap.
26 	 * Only populated if populate_freeable_maps == 1
27 	 */
28 	struct list_head freeable_maps;
29 	/* lock protects maps and freeable_maps. */
30 	struct mutex lock;
31 	struct mm_struct *mm;
32 	struct mmu_notifier mn;
33 
34 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
35 	/* Device for which DMA memory is allocated. */
36 	struct device *dma_dev;
37 #endif
38 
39 #ifdef CONFIG_XEN_GNTDEV_DMABUF
40 	struct gntdev_dmabuf_priv *dmabuf_priv;
41 #endif
42 };
43 
44 struct gntdev_unmap_notify {
45 	int flags;
46 	/* Address relative to the start of the gntdev_grant_map. */
47 	int addr;
48 	int event;
49 };
50 
51 struct gntdev_grant_map {
52 	struct list_head next;
53 	struct vm_area_struct *vma;
54 	int index;
55 	int count;
56 	int flags;
57 	refcount_t users;
58 	struct gntdev_unmap_notify notify;
59 	struct ioctl_gntdev_grant_ref *grants;
60 	struct gnttab_map_grant_ref   *map_ops;
61 	struct gnttab_unmap_grant_ref *unmap_ops;
62 	struct gnttab_map_grant_ref   *kmap_ops;
63 	struct gnttab_unmap_grant_ref *kunmap_ops;
64 	struct page **pages;
65 	unsigned long pages_vm_start;
66 
67 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
68 	/*
69 	 * If dmabuf_vaddr is not NULL then this mapping is backed by DMA
70 	 * capable memory.
71 	 */
72 
73 	struct device *dma_dev;
74 	/* Flags used to create this DMA buffer: GNTDEV_DMA_FLAG_XXX. */
75 	int dma_flags;
76 	void *dma_vaddr;
77 	dma_addr_t dma_bus_addr;
78 	/* Needed to avoid allocation in gnttab_dma_free_pages(). */
79 	xen_pfn_t *frames;
80 #endif
81 };
82 
83 struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count,
84 					  int dma_flags);
85 
86 void gntdev_add_map(struct gntdev_priv *priv, struct gntdev_grant_map *add);
87 
88 void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map);
89 
90 bool gntdev_account_mapped_pages(int count);
91 
92 int gntdev_map_grant_pages(struct gntdev_grant_map *map);
93 
94 #endif
95