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 */
19struct 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
34static inline struct ioptdesc *folio_ioptdesc(struct folio *folio)
35{
36 return (struct ioptdesc *)folio;
37}
38
39static inline struct folio *ioptdesc_folio(struct ioptdesc *iopt)
40{
41 return (struct folio *)iopt;
42}
43
44static inline struct ioptdesc *virt_to_ioptdesc(void *virt)
45{
46 return folio_ioptdesc(folio: virt_to_folio(x: virt));
47}
48
49void *iommu_alloc_pages_node_sz(int nid, gfp_t gfp, size_t size);
50void iommu_free_pages(void *virt);
51void 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 */
58static inline void iommu_pages_list_add(struct iommu_pages_list *list,
59 void *virt)
60{
61 list_add_tail(new: &virt_to_ioptdesc(virt)->iopt_freelist_elm, head: &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 */
72static inline void iommu_pages_list_splice(struct iommu_pages_list *from,
73 struct iommu_pages_list *to)
74{
75 list_splice(list: &from->pages, head: &to->pages);
76}
77
78/**
79 * iommu_pages_list_empty - True if the list is empty
80 * @list: List to check
81 */
82static inline bool iommu_pages_list_empty(struct iommu_pages_list *list)
83{
84 return list_empty(head: &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 */
96static 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