1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (c) 2024, Google LLC.
4 * Pasha Tatashin <pasha.tatashin@soleen.com>
5 */
6
7 #ifndef __IOMMU_PAGES_H
8 #define __IOMMU_PAGES_H
9
10 #include <linux/iommu.h>
11
12 /**
13 * struct ioptdesc - Memory descriptor for IOMMU page tables
14 * @iopt_freelist_elm: List element for a struct iommu_pages_list
15 *
16 * This struct overlays struct page for now. Do not modify without a good
17 * understanding of the issues.
18 */
19 struct ioptdesc {
20 unsigned long __page_flags;
21
22 struct list_head iopt_freelist_elm;
23 unsigned long __page_mapping;
24 pgoff_t __index;
25 void *_private;
26
27 unsigned int __page_type;
28 atomic_t __page_refcount;
29 #ifdef CONFIG_MEMCG
30 unsigned long memcg_data;
31 #endif
32 };
33
folio_ioptdesc(struct folio * folio)34 static inline struct ioptdesc *folio_ioptdesc(struct folio *folio)
35 {
36 return (struct ioptdesc *)folio;
37 }
38
ioptdesc_folio(struct ioptdesc * iopt)39 static inline struct folio *ioptdesc_folio(struct ioptdesc *iopt)
40 {
41 return (struct folio *)iopt;
42 }
43
virt_to_ioptdesc(void * virt)44 static inline struct ioptdesc *virt_to_ioptdesc(void *virt)
45 {
46 return folio_ioptdesc(virt_to_folio(virt));
47 }
48
49 void *iommu_alloc_pages_node_sz(int nid, gfp_t gfp, size_t size);
50 void iommu_free_pages(void *virt);
51 void iommu_put_pages_list(struct iommu_pages_list *list);
52
53 /**
54 * iommu_pages_list_add - add the page to a iommu_pages_list
55 * @list: List to add the page to
56 * @virt: Address returned from iommu_alloc_pages_node_sz()
57 */
iommu_pages_list_add(struct iommu_pages_list * list,void * virt)58 static inline void iommu_pages_list_add(struct iommu_pages_list *list,
59 void *virt)
60 {
61 list_add_tail(&virt_to_ioptdesc(virt)->iopt_freelist_elm, &list->pages);
62 }
63
64 /**
65 * iommu_pages_list_splice - Put all the pages in list from into list to
66 * @from: Source list of pages
67 * @to: Destination list of pages
68 *
69 * from must be re-initialized after calling this function if it is to be
70 * used again.
71 */
iommu_pages_list_splice(struct iommu_pages_list * from,struct iommu_pages_list * to)72 static inline void iommu_pages_list_splice(struct iommu_pages_list *from,
73 struct iommu_pages_list *to)
74 {
75 list_splice(&from->pages, &to->pages);
76 }
77
78 /**
79 * iommu_pages_list_empty - True if the list is empty
80 * @list: List to check
81 */
iommu_pages_list_empty(struct iommu_pages_list * list)82 static inline bool iommu_pages_list_empty(struct iommu_pages_list *list)
83 {
84 return list_empty(&list->pages);
85 }
86
87 /**
88 * iommu_alloc_pages_sz - Allocate a zeroed page of a given size from
89 * specific NUMA node
90 * @nid: memory NUMA node id
91 * @gfp: buddy allocator flags
92 * @size: Memory size to allocate, this is rounded up to a power of 2
93 *
94 * Returns the virtual address of the allocated page.
95 */
iommu_alloc_pages_sz(gfp_t gfp,size_t size)96 static inline void *iommu_alloc_pages_sz(gfp_t gfp, size_t size)
97 {
98 return iommu_alloc_pages_node_sz(NUMA_NO_NODE, gfp, size);
99 }
100
101 #endif /* __IOMMU_PAGES_H */
102