xref: /linux/drivers/iommu/iommu.c (revision 068df0f34e81bc06c5eb5012ec2eda25624e87aa)
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 #include <linux/device.h>
20 #include <linux/kernel.h>
21 #include <linux/bug.h>
22 #include <linux/types.h>
23 #include <linux/module.h>
24 #include <linux/slab.h>
25 #include <linux/errno.h>
26 #include <linux/iommu.h>
27 
28 static void iommu_bus_init(struct bus_type *bus, struct iommu_ops *ops)
29 {
30 }
31 
32 /**
33  * bus_set_iommu - set iommu-callbacks for the bus
34  * @bus: bus.
35  * @ops: the callbacks provided by the iommu-driver
36  *
37  * This function is called by an iommu driver to set the iommu methods
38  * used for a particular bus. Drivers for devices on that bus can use
39  * the iommu-api after these ops are registered.
40  * This special function is needed because IOMMUs are usually devices on
41  * the bus itself, so the iommu drivers are not initialized when the bus
42  * is set up. With this function the iommu-driver can set the iommu-ops
43  * afterwards.
44  */
45 int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops)
46 {
47 	if (bus->iommu_ops != NULL)
48 		return -EBUSY;
49 
50 	bus->iommu_ops = ops;
51 
52 	/* Do IOMMU specific setup for this bus-type */
53 	iommu_bus_init(bus, ops);
54 
55 	return 0;
56 }
57 EXPORT_SYMBOL_GPL(bus_set_iommu);
58 
59 bool iommu_present(struct bus_type *bus)
60 {
61 	return bus->iommu_ops != NULL;
62 }
63 EXPORT_SYMBOL_GPL(iommu_present);
64 
65 /**
66  * iommu_set_fault_handler() - set a fault handler for an iommu domain
67  * @domain: iommu domain
68  * @handler: fault handler
69  *
70  * This function should be used by IOMMU users which want to be notified
71  * whenever an IOMMU fault happens.
72  *
73  * The fault handler itself should return 0 on success, and an appropriate
74  * error code otherwise.
75  */
76 void iommu_set_fault_handler(struct iommu_domain *domain,
77 					iommu_fault_handler_t handler)
78 {
79 	BUG_ON(!domain);
80 
81 	domain->handler = handler;
82 }
83 EXPORT_SYMBOL_GPL(iommu_set_fault_handler);
84 
85 struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
86 {
87 	struct iommu_domain *domain;
88 	int ret;
89 
90 	if (bus == NULL || bus->iommu_ops == NULL)
91 		return NULL;
92 
93 	domain = kmalloc(sizeof(*domain), GFP_KERNEL);
94 	if (!domain)
95 		return NULL;
96 
97 	domain->ops = bus->iommu_ops;
98 
99 	ret = domain->ops->domain_init(domain);
100 	if (ret)
101 		goto out_free;
102 
103 	return domain;
104 
105 out_free:
106 	kfree(domain);
107 
108 	return NULL;
109 }
110 EXPORT_SYMBOL_GPL(iommu_domain_alloc);
111 
112 void iommu_domain_free(struct iommu_domain *domain)
113 {
114 	if (likely(domain->ops->domain_destroy != NULL))
115 		domain->ops->domain_destroy(domain);
116 
117 	kfree(domain);
118 }
119 EXPORT_SYMBOL_GPL(iommu_domain_free);
120 
121 int iommu_attach_device(struct iommu_domain *domain, struct device *dev)
122 {
123 	if (unlikely(domain->ops->attach_dev == NULL))
124 		return -ENODEV;
125 
126 	return domain->ops->attach_dev(domain, dev);
127 }
128 EXPORT_SYMBOL_GPL(iommu_attach_device);
129 
130 void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
131 {
132 	if (unlikely(domain->ops->detach_dev == NULL))
133 		return;
134 
135 	domain->ops->detach_dev(domain, dev);
136 }
137 EXPORT_SYMBOL_GPL(iommu_detach_device);
138 
139 phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
140 			       unsigned long iova)
141 {
142 	if (unlikely(domain->ops->iova_to_phys == NULL))
143 		return 0;
144 
145 	return domain->ops->iova_to_phys(domain, iova);
146 }
147 EXPORT_SYMBOL_GPL(iommu_iova_to_phys);
148 
149 int iommu_domain_has_cap(struct iommu_domain *domain,
150 			 unsigned long cap)
151 {
152 	if (unlikely(domain->ops->domain_has_cap == NULL))
153 		return 0;
154 
155 	return domain->ops->domain_has_cap(domain, cap);
156 }
157 EXPORT_SYMBOL_GPL(iommu_domain_has_cap);
158 
159 int iommu_map(struct iommu_domain *domain, unsigned long iova,
160 	      phys_addr_t paddr, int gfp_order, int prot)
161 {
162 	size_t size;
163 
164 	if (unlikely(domain->ops->map == NULL))
165 		return -ENODEV;
166 
167 	size         = PAGE_SIZE << gfp_order;
168 
169 	BUG_ON(!IS_ALIGNED(iova | paddr, size));
170 
171 	return domain->ops->map(domain, iova, paddr, gfp_order, prot);
172 }
173 EXPORT_SYMBOL_GPL(iommu_map);
174 
175 int iommu_unmap(struct iommu_domain *domain, unsigned long iova, int gfp_order)
176 {
177 	size_t size;
178 
179 	if (unlikely(domain->ops->unmap == NULL))
180 		return -ENODEV;
181 
182 	size         = PAGE_SIZE << gfp_order;
183 
184 	BUG_ON(!IS_ALIGNED(iova, size));
185 
186 	return domain->ops->unmap(domain, iova, gfp_order);
187 }
188 EXPORT_SYMBOL_GPL(iommu_unmap);
189