include/linux/iommu.h

   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
  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 */