drivers/iommu/iommu.c

   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 = kzalloc(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);