xref: /linux-6.15/include/linux/iommu.h (revision db4e8395)
1 /*
2  * Copyright (C) 2007-2008 Advanced Micro Devices, Inc.
3  * Author: Joerg Roedel <[email protected]>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published
7  * by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
17  */
18 
19 #ifndef __LINUX_IOMMU_H
20 #define __LINUX_IOMMU_H
21 
22 #include <linux/errno.h>
23 
24 #define IOMMU_READ	(1)
25 #define IOMMU_WRITE	(2)
26 #define IOMMU_CACHE	(4) /* DMA cache coherency */
27 
28 struct iommu_ops;
29 struct bus_type;
30 struct device;
31 struct iommu_domain;
32 
33 /* iommu fault flags */
34 #define IOMMU_FAULT_READ	0x0
35 #define IOMMU_FAULT_WRITE	0x1
36 
37 typedef int (*iommu_fault_handler_t)(struct iommu_domain *,
38 				struct device *, unsigned long, int);
39 
40 struct iommu_domain {
41 	struct iommu_ops *ops;
42 	void *priv;
43 	iommu_fault_handler_t handler;
44 };
45 
46 #define IOMMU_CAP_CACHE_COHERENCY	0x1
47 #define IOMMU_CAP_INTR_REMAP		0x2	/* isolates device intrs */
48 
49 #ifdef CONFIG_IOMMU_API
50 
51 struct iommu_ops {
52 	int (*domain_init)(struct iommu_domain *domain);
53 	void (*domain_destroy)(struct iommu_domain *domain);
54 	int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
55 	void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
56 	int (*map)(struct iommu_domain *domain, unsigned long iova,
57 		   phys_addr_t paddr, int gfp_order, int prot);
58 	int (*unmap)(struct iommu_domain *domain, unsigned long iova,
59 		     int gfp_order);
60 	phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,
61 				    unsigned long iova);
62 	int (*domain_has_cap)(struct iommu_domain *domain,
63 			      unsigned long cap);
64 };
65 
66 extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops);
67 extern bool iommu_present(struct bus_type *bus);
68 extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus);
69 extern void iommu_domain_free(struct iommu_domain *domain);
70 extern int iommu_attach_device(struct iommu_domain *domain,
71 			       struct device *dev);
72 extern void iommu_detach_device(struct iommu_domain *domain,
73 				struct device *dev);
74 extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
75 		     phys_addr_t paddr, int gfp_order, int prot);
76 extern int iommu_unmap(struct iommu_domain *domain, unsigned long iova,
77 		       int gfp_order);
78 extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
79 				      unsigned long iova);
80 extern int iommu_domain_has_cap(struct iommu_domain *domain,
81 				unsigned long cap);
82 extern void iommu_set_fault_handler(struct iommu_domain *domain,
83 					iommu_fault_handler_t handler);
84 
85 /**
86  * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework
87  * @domain: the iommu domain where the fault has happened
88  * @dev: the device where the fault has happened
89  * @iova: the faulting address
90  * @flags: mmu fault flags (e.g. IOMMU_FAULT_READ/IOMMU_FAULT_WRITE/...)
91  *
92  * This function should be called by the low-level IOMMU implementations
93  * whenever IOMMU faults happen, to allow high-level users, that are
94  * interested in such events, to know about them.
95  *
96  * This event may be useful for several possible use cases:
97  * - mere logging of the event
98  * - dynamic TLB/PTE loading
99  * - if restarting of the faulting device is required
100  *
101  * Returns 0 on success and an appropriate error code otherwise (if dynamic
102  * PTE/TLB loading will one day be supported, implementations will be able
103  * to tell whether it succeeded or not according to this return value).
104  *
105  * Specifically, -ENOSYS is returned if a fault handler isn't installed
106  * (though fault handlers can also return -ENOSYS, in case they want to
107  * elicit the default behavior of the IOMMU drivers).
108  */
109 static inline int report_iommu_fault(struct iommu_domain *domain,
110 		struct device *dev, unsigned long iova, int flags)
111 {
112 	int ret = -ENOSYS;
113 
114 	/*
115 	 * if upper layers showed interest and installed a fault handler,
116 	 * invoke it.
117 	 */
118 	if (domain->handler)
119 		ret = domain->handler(domain, dev, iova, flags);
120 
121 	return ret;
122 }
123 
124 #else /* CONFIG_IOMMU_API */
125 
126 struct iommu_ops {};
127 
128 static inline bool iommu_present(struct bus_type *bus)
129 {
130 	return false;
131 }
132 
133 static inline struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
134 {
135 	return NULL;
136 }
137 
138 static inline void iommu_domain_free(struct iommu_domain *domain)
139 {
140 }
141 
142 static inline int iommu_attach_device(struct iommu_domain *domain,
143 				      struct device *dev)
144 {
145 	return -ENODEV;
146 }
147 
148 static inline void iommu_detach_device(struct iommu_domain *domain,
149 				       struct device *dev)
150 {
151 }
152 
153 static inline int iommu_map(struct iommu_domain *domain, unsigned long iova,
154 			    phys_addr_t paddr, int gfp_order, int prot)
155 {
156 	return -ENODEV;
157 }
158 
159 static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova,
160 			      int gfp_order)
161 {
162 	return -ENODEV;
163 }
164 
165 static inline phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
166 					     unsigned long iova)
167 {
168 	return 0;
169 }
170 
171 static inline int domain_has_cap(struct iommu_domain *domain,
172 				 unsigned long cap)
173 {
174 	return 0;
175 }
176 
177 static inline void iommu_set_fault_handler(struct iommu_domain *domain,
178 					iommu_fault_handler_t handler)
179 {
180 }
181 
182 #endif /* CONFIG_IOMMU_API */
183 
184 #endif /* __LINUX_IOMMU_H */
185