1/*
2 * Copyright (C) 2007-2008 Advanced Micro Devices, Inc.
3 * Author: Joerg Roedel <joerg.roedel@amd.com>
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
28struct iommu_ops;
29struct bus_type;
30struct device;
31struct iommu_domain;
32
33/* iommu fault flags */
34#define IOMMU_FAULT_READ	0x0
35#define IOMMU_FAULT_WRITE	0x1
36
37typedef int (*iommu_fault_handler_t)(struct iommu_domain *,
38				struct device *, unsigned long, int);
39
40struct 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/**
52 * struct iommu_ops - iommu ops and capabilities
53 * @domain_init: init iommu domain
54 * @domain_destroy: destroy iommu domain
55 * @attach_dev: attach device to an iommu domain
56 * @detach_dev: detach device from an iommu domain
57 * @map: map a physically contiguous memory region to an iommu domain
58 * @unmap: unmap a physically contiguous memory region from an iommu domain
59 * @iova_to_phys: translate iova to physical address
60 * @domain_has_cap: domain capabilities query
61 * @commit: commit iommu domain
62 * @pgsize_bitmap: bitmap of supported page sizes
63 */
64struct iommu_ops {
65	int (*domain_init)(struct iommu_domain *domain);
66	void (*domain_destroy)(struct iommu_domain *domain);
67	int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
68	void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
69	int (*map)(struct iommu_domain *domain, unsigned long iova,
70		   phys_addr_t paddr, size_t size, int prot);
71	size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
72		     size_t size);
73	phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,
74				    unsigned long iova);
75	int (*domain_has_cap)(struct iommu_domain *domain,
76			      unsigned long cap);
77	int (*device_group)(struct device *dev, unsigned int *groupid);
78	unsigned long pgsize_bitmap;
79};
80
81extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops);
82extern bool iommu_present(struct bus_type *bus);
83extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus);
84extern void iommu_domain_free(struct iommu_domain *domain);
85extern int iommu_attach_device(struct iommu_domain *domain,
86			       struct device *dev);
87extern void iommu_detach_device(struct iommu_domain *domain,
88				struct device *dev);
89extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
90		     phys_addr_t paddr, size_t size, int prot);
91extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
92		       size_t size);
93extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
94				      unsigned long iova);
95extern int iommu_domain_has_cap(struct iommu_domain *domain,
96				unsigned long cap);
97extern void iommu_set_fault_handler(struct iommu_domain *domain,
98					iommu_fault_handler_t handler);
99extern int iommu_device_group(struct device *dev, unsigned int *groupid);
100
101/**
102 * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework
103 * @domain: the iommu domain where the fault has happened
104 * @dev: the device where the fault has happened
105 * @iova: the faulting address
106 * @flags: mmu fault flags (e.g. IOMMU_FAULT_READ/IOMMU_FAULT_WRITE/...)
107 *
108 * This function should be called by the low-level IOMMU implementations
109 * whenever IOMMU faults happen, to allow high-level users, that are
110 * interested in such events, to know about them.
111 *
112 * This event may be useful for several possible use cases:
113 * - mere logging of the event
114 * - dynamic TLB/PTE loading
115 * - if restarting of the faulting device is required
116 *
117 * Returns 0 on success and an appropriate error code otherwise (if dynamic
118 * PTE/TLB loading will one day be supported, implementations will be able
119 * to tell whether it succeeded or not according to this return value).
120 *
121 * Specifically, -ENOSYS is returned if a fault handler isn't installed
122 * (though fault handlers can also return -ENOSYS, in case they want to
123 * elicit the default behavior of the IOMMU drivers).
124 */
125static inline int report_iommu_fault(struct iommu_domain *domain,
126		struct device *dev, unsigned long iova, int flags)
127{
128	int ret = -ENOSYS;
129
130	/*
131	 * if upper layers showed interest and installed a fault handler,
132	 * invoke it.
133	 */
134	if (domain->handler)
135		ret = domain->handler(domain, dev, iova, flags);
136
137	return ret;
138}
139
140#else /* CONFIG_IOMMU_API */
141
142struct iommu_ops {};
143
144static inline bool iommu_present(struct bus_type *bus)
145{
146	return false;
147}
148
149static inline struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
150{
151	return NULL;
152}
153
154static inline void iommu_domain_free(struct iommu_domain *domain)
155{
156}
157
158static inline int iommu_attach_device(struct iommu_domain *domain,
159				      struct device *dev)
160{
161	return -ENODEV;
162}
163
164static inline void iommu_detach_device(struct iommu_domain *domain,
165				       struct device *dev)
166{
167}
168
169static inline int iommu_map(struct iommu_domain *domain, unsigned long iova,
170			    phys_addr_t paddr, int gfp_order, int prot)
171{
172	return -ENODEV;
173}
174
175static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova,
176			      int gfp_order)
177{
178	return -ENODEV;
179}
180
181static inline phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
182					     unsigned long iova)
183{
184	return 0;
185}
186
187static inline int domain_has_cap(struct iommu_domain *domain,
188				 unsigned long cap)
189{
190	return 0;
191}
192
193static inline void iommu_set_fault_handler(struct iommu_domain *domain,
194					iommu_fault_handler_t handler)
195{
196}
197
198static inline int iommu_device_group(struct device *dev, unsigned int *groupid)
199{
200	return -ENODEV;
201}
202
203#endif /* CONFIG_IOMMU_API */
204
205#endif /* __LINUX_IOMMU_H */
206