xref: /linux-6.15/include/linux/iova.h (revision cd3bc044)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (c) 2006, Intel Corporation.
4  *
5  * Copyright (C) 2006-2008 Intel Corporation
6  * Author: Anil S Keshavamurthy <[email protected]>
7  */
8 
9 #ifndef _IOVA_H_
10 #define _IOVA_H_
11 
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/rbtree.h>
15 #include <linux/dma-mapping.h>
16 
17 /* iova structure */
18 struct iova {
19 	struct rb_node	node;
20 	unsigned long	pfn_hi; /* Highest allocated pfn */
21 	unsigned long	pfn_lo; /* Lowest allocated pfn */
22 };
23 
24 struct iova_magazine;
25 struct iova_cpu_rcache;
26 
27 #define IOVA_RANGE_CACHE_MAX_SIZE 6	/* log of max cached IOVA range size (in pages) */
28 #define MAX_GLOBAL_MAGS 32	/* magazines per bin */
29 
30 struct iova_rcache {
31 	spinlock_t lock;
32 	unsigned long depot_size;
33 	struct iova_magazine *depot[MAX_GLOBAL_MAGS];
34 	struct iova_cpu_rcache __percpu *cpu_rcaches;
35 };
36 
37 /* holds all the iova translations for a domain */
38 struct iova_domain {
39 	spinlock_t	iova_rbtree_lock; /* Lock to protect update of rbtree */
40 	struct rb_root	rbroot;		/* iova domain rbtree root */
41 	struct rb_node	*cached_node;	/* Save last alloced node */
42 	struct rb_node	*cached32_node; /* Save last 32-bit alloced node */
43 	unsigned long	granule;	/* pfn granularity for this domain */
44 	unsigned long	start_pfn;	/* Lower limit for this domain */
45 	unsigned long	dma_32bit_pfn;
46 	unsigned long	max32_alloc_size; /* Size of last failed allocation */
47 	struct iova	anchor;		/* rbtree lookup anchor */
48 
49 	struct iova_rcache rcaches[IOVA_RANGE_CACHE_MAX_SIZE];	/* IOVA range caches */
50 	struct hlist_node	cpuhp_dead;
51 };
52 
53 static inline unsigned long iova_size(struct iova *iova)
54 {
55 	return iova->pfn_hi - iova->pfn_lo + 1;
56 }
57 
58 static inline unsigned long iova_shift(struct iova_domain *iovad)
59 {
60 	return __ffs(iovad->granule);
61 }
62 
63 static inline unsigned long iova_mask(struct iova_domain *iovad)
64 {
65 	return iovad->granule - 1;
66 }
67 
68 static inline size_t iova_offset(struct iova_domain *iovad, dma_addr_t iova)
69 {
70 	return iova & iova_mask(iovad);
71 }
72 
73 static inline size_t iova_align(struct iova_domain *iovad, size_t size)
74 {
75 	return ALIGN(size, iovad->granule);
76 }
77 
78 static inline dma_addr_t iova_dma_addr(struct iova_domain *iovad, struct iova *iova)
79 {
80 	return (dma_addr_t)iova->pfn_lo << iova_shift(iovad);
81 }
82 
83 static inline unsigned long iova_pfn(struct iova_domain *iovad, dma_addr_t iova)
84 {
85 	return iova >> iova_shift(iovad);
86 }
87 
88 #if IS_ENABLED(CONFIG_IOMMU_IOVA)
89 int iova_cache_get(void);
90 void iova_cache_put(void);
91 
92 void free_iova(struct iova_domain *iovad, unsigned long pfn);
93 void __free_iova(struct iova_domain *iovad, struct iova *iova);
94 struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size,
95 	unsigned long limit_pfn,
96 	bool size_aligned);
97 void free_iova_fast(struct iova_domain *iovad, unsigned long pfn,
98 		    unsigned long size);
99 unsigned long alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
100 			      unsigned long limit_pfn, bool flush_rcache);
101 struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
102 	unsigned long pfn_hi);
103 void init_iova_domain(struct iova_domain *iovad, unsigned long granule,
104 	unsigned long start_pfn);
105 struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
106 void put_iova_domain(struct iova_domain *iovad);
107 #else
108 static inline int iova_cache_get(void)
109 {
110 	return -ENOTSUPP;
111 }
112 
113 static inline void iova_cache_put(void)
114 {
115 }
116 
117 static inline void free_iova(struct iova_domain *iovad, unsigned long pfn)
118 {
119 }
120 
121 static inline void __free_iova(struct iova_domain *iovad, struct iova *iova)
122 {
123 }
124 
125 static inline struct iova *alloc_iova(struct iova_domain *iovad,
126 				      unsigned long size,
127 				      unsigned long limit_pfn,
128 				      bool size_aligned)
129 {
130 	return NULL;
131 }
132 
133 static inline void free_iova_fast(struct iova_domain *iovad,
134 				  unsigned long pfn,
135 				  unsigned long size)
136 {
137 }
138 
139 static inline unsigned long alloc_iova_fast(struct iova_domain *iovad,
140 					    unsigned long size,
141 					    unsigned long limit_pfn,
142 					    bool flush_rcache)
143 {
144 	return 0;
145 }
146 
147 static inline struct iova *reserve_iova(struct iova_domain *iovad,
148 					unsigned long pfn_lo,
149 					unsigned long pfn_hi)
150 {
151 	return NULL;
152 }
153 
154 static inline void init_iova_domain(struct iova_domain *iovad,
155 				    unsigned long granule,
156 				    unsigned long start_pfn)
157 {
158 }
159 
160 static inline struct iova *find_iova(struct iova_domain *iovad,
161 				     unsigned long pfn)
162 {
163 	return NULL;
164 }
165 
166 static inline void put_iova_domain(struct iova_domain *iovad)
167 {
168 }
169 
170 #endif
171 
172 #endif
173