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 #define pr_fmt(fmt) "%s: " fmt, __func__ 20 21 #include <linux/device.h> 22 #include <linux/kernel.h> 23 #include <linux/bug.h> 24 #include <linux/types.h> 25 #include <linux/module.h> 26 #include <linux/slab.h> 27 #include <linux/errno.h> 28 #include <linux/iommu.h> 29 30 static ssize_t show_iommu_group(struct device *dev, 31 struct device_attribute *attr, char *buf) 32 { 33 unsigned int groupid; 34 35 if (iommu_device_group(dev, &groupid)) 36 return 0; 37 38 return sprintf(buf, "%u", groupid); 39 } 40 static DEVICE_ATTR(iommu_group, S_IRUGO, show_iommu_group, NULL); 41 42 static int add_iommu_group(struct device *dev, void *data) 43 { 44 unsigned int groupid; 45 46 if (iommu_device_group(dev, &groupid) == 0) 47 return device_create_file(dev, &dev_attr_iommu_group); 48 49 return 0; 50 } 51 52 static int remove_iommu_group(struct device *dev) 53 { 54 unsigned int groupid; 55 56 if (iommu_device_group(dev, &groupid) == 0) 57 device_remove_file(dev, &dev_attr_iommu_group); 58 59 return 0; 60 } 61 62 static int iommu_device_notifier(struct notifier_block *nb, 63 unsigned long action, void *data) 64 { 65 struct device *dev = data; 66 67 if (action == BUS_NOTIFY_ADD_DEVICE) 68 return add_iommu_group(dev, NULL); 69 else if (action == BUS_NOTIFY_DEL_DEVICE) 70 return remove_iommu_group(dev); 71 72 return 0; 73 } 74 75 static struct notifier_block iommu_device_nb = { 76 .notifier_call = iommu_device_notifier, 77 }; 78 79 static void iommu_bus_init(struct bus_type *bus, struct iommu_ops *ops) 80 { 81 bus_register_notifier(bus, &iommu_device_nb); 82 bus_for_each_dev(bus, NULL, NULL, add_iommu_group); 83 } 84 85 /** 86 * bus_set_iommu - set iommu-callbacks for the bus 87 * @bus: bus. 88 * @ops: the callbacks provided by the iommu-driver 89 * 90 * This function is called by an iommu driver to set the iommu methods 91 * used for a particular bus. Drivers for devices on that bus can use 92 * the iommu-api after these ops are registered. 93 * This special function is needed because IOMMUs are usually devices on 94 * the bus itself, so the iommu drivers are not initialized when the bus 95 * is set up. With this function the iommu-driver can set the iommu-ops 96 * afterwards. 97 */ 98 int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops) 99 { 100 if (bus->iommu_ops != NULL) 101 return -EBUSY; 102 103 bus->iommu_ops = ops; 104 105 /* Do IOMMU specific setup for this bus-type */ 106 iommu_bus_init(bus, ops); 107 108 return 0; 109 } 110 EXPORT_SYMBOL_GPL(bus_set_iommu); 111 112 bool iommu_present(struct bus_type *bus) 113 { 114 return bus->iommu_ops != NULL; 115 } 116 EXPORT_SYMBOL_GPL(iommu_present); 117 118 /** 119 * iommu_set_fault_handler() - set a fault handler for an iommu domain 120 * @domain: iommu domain 121 * @handler: fault handler 122 * @token: user data, will be passed back to the fault handler 123 * 124 * This function should be used by IOMMU users which want to be notified 125 * whenever an IOMMU fault happens. 126 * 127 * The fault handler itself should return 0 on success, and an appropriate 128 * error code otherwise. 129 */ 130 void iommu_set_fault_handler(struct iommu_domain *domain, 131 iommu_fault_handler_t handler, 132 void *token) 133 { 134 BUG_ON(!domain); 135 136 domain->handler = handler; 137 domain->handler_token = token; 138 } 139 EXPORT_SYMBOL_GPL(iommu_set_fault_handler); 140 141 struct iommu_domain *iommu_domain_alloc(struct bus_type *bus) 142 { 143 struct iommu_domain *domain; 144 int ret; 145 146 if (bus == NULL || bus->iommu_ops == NULL) 147 return NULL; 148 149 domain = kzalloc(sizeof(*domain), GFP_KERNEL); 150 if (!domain) 151 return NULL; 152 153 domain->ops = bus->iommu_ops; 154 155 ret = domain->ops->domain_init(domain); 156 if (ret) 157 goto out_free; 158 159 return domain; 160 161 out_free: 162 kfree(domain); 163 164 return NULL; 165 } 166 EXPORT_SYMBOL_GPL(iommu_domain_alloc); 167 168 void iommu_domain_free(struct iommu_domain *domain) 169 { 170 if (likely(domain->ops->domain_destroy != NULL)) 171 domain->ops->domain_destroy(domain); 172 173 kfree(domain); 174 } 175 EXPORT_SYMBOL_GPL(iommu_domain_free); 176 177 int iommu_attach_device(struct iommu_domain *domain, struct device *dev) 178 { 179 if (unlikely(domain->ops->attach_dev == NULL)) 180 return -ENODEV; 181 182 return domain->ops->attach_dev(domain, dev); 183 } 184 EXPORT_SYMBOL_GPL(iommu_attach_device); 185 186 void iommu_detach_device(struct iommu_domain *domain, struct device *dev) 187 { 188 if (unlikely(domain->ops->detach_dev == NULL)) 189 return; 190 191 domain->ops->detach_dev(domain, dev); 192 } 193 EXPORT_SYMBOL_GPL(iommu_detach_device); 194 195 phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, 196 unsigned long iova) 197 { 198 if (unlikely(domain->ops->iova_to_phys == NULL)) 199 return 0; 200 201 return domain->ops->iova_to_phys(domain, iova); 202 } 203 EXPORT_SYMBOL_GPL(iommu_iova_to_phys); 204 205 int iommu_domain_has_cap(struct iommu_domain *domain, 206 unsigned long cap) 207 { 208 if (unlikely(domain->ops->domain_has_cap == NULL)) 209 return 0; 210 211 return domain->ops->domain_has_cap(domain, cap); 212 } 213 EXPORT_SYMBOL_GPL(iommu_domain_has_cap); 214 215 int iommu_map(struct iommu_domain *domain, unsigned long iova, 216 phys_addr_t paddr, size_t size, int prot) 217 { 218 unsigned long orig_iova = iova; 219 unsigned int min_pagesz; 220 size_t orig_size = size; 221 int ret = 0; 222 223 if (unlikely(domain->ops->map == NULL)) 224 return -ENODEV; 225 226 /* find out the minimum page size supported */ 227 min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap); 228 229 /* 230 * both the virtual address and the physical one, as well as 231 * the size of the mapping, must be aligned (at least) to the 232 * size of the smallest page supported by the hardware 233 */ 234 if (!IS_ALIGNED(iova | paddr | size, min_pagesz)) { 235 pr_err("unaligned: iova 0x%lx pa 0x%lx size 0x%lx min_pagesz " 236 "0x%x\n", iova, (unsigned long)paddr, 237 (unsigned long)size, min_pagesz); 238 return -EINVAL; 239 } 240 241 pr_debug("map: iova 0x%lx pa 0x%lx size 0x%lx\n", iova, 242 (unsigned long)paddr, (unsigned long)size); 243 244 while (size) { 245 unsigned long pgsize, addr_merge = iova | paddr; 246 unsigned int pgsize_idx; 247 248 /* Max page size that still fits into 'size' */ 249 pgsize_idx = __fls(size); 250 251 /* need to consider alignment requirements ? */ 252 if (likely(addr_merge)) { 253 /* Max page size allowed by both iova and paddr */ 254 unsigned int align_pgsize_idx = __ffs(addr_merge); 255 256 pgsize_idx = min(pgsize_idx, align_pgsize_idx); 257 } 258 259 /* build a mask of acceptable page sizes */ 260 pgsize = (1UL << (pgsize_idx + 1)) - 1; 261 262 /* throw away page sizes not supported by the hardware */ 263 pgsize &= domain->ops->pgsize_bitmap; 264 265 /* make sure we're still sane */ 266 BUG_ON(!pgsize); 267 268 /* pick the biggest page */ 269 pgsize_idx = __fls(pgsize); 270 pgsize = 1UL << pgsize_idx; 271 272 pr_debug("mapping: iova 0x%lx pa 0x%lx pgsize %lu\n", iova, 273 (unsigned long)paddr, pgsize); 274 275 ret = domain->ops->map(domain, iova, paddr, pgsize, prot); 276 if (ret) 277 break; 278 279 iova += pgsize; 280 paddr += pgsize; 281 size -= pgsize; 282 } 283 284 /* unroll mapping in case something went wrong */ 285 if (ret) 286 iommu_unmap(domain, orig_iova, orig_size - size); 287 288 return ret; 289 } 290 EXPORT_SYMBOL_GPL(iommu_map); 291 292 size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) 293 { 294 size_t unmapped_page, unmapped = 0; 295 unsigned int min_pagesz; 296 297 if (unlikely(domain->ops->unmap == NULL)) 298 return -ENODEV; 299 300 /* find out the minimum page size supported */ 301 min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap); 302 303 /* 304 * The virtual address, as well as the size of the mapping, must be 305 * aligned (at least) to the size of the smallest page supported 306 * by the hardware 307 */ 308 if (!IS_ALIGNED(iova | size, min_pagesz)) { 309 pr_err("unaligned: iova 0x%lx size 0x%lx min_pagesz 0x%x\n", 310 iova, (unsigned long)size, min_pagesz); 311 return -EINVAL; 312 } 313 314 pr_debug("unmap this: iova 0x%lx size 0x%lx\n", iova, 315 (unsigned long)size); 316 317 /* 318 * Keep iterating until we either unmap 'size' bytes (or more) 319 * or we hit an area that isn't mapped. 320 */ 321 while (unmapped < size) { 322 size_t left = size - unmapped; 323 324 unmapped_page = domain->ops->unmap(domain, iova, left); 325 if (!unmapped_page) 326 break; 327 328 pr_debug("unmapped: iova 0x%lx size %lx\n", iova, 329 (unsigned long)unmapped_page); 330 331 iova += unmapped_page; 332 unmapped += unmapped_page; 333 } 334 335 return unmapped; 336 } 337 EXPORT_SYMBOL_GPL(iommu_unmap); 338 339 int iommu_device_group(struct device *dev, unsigned int *groupid) 340 { 341 if (iommu_present(dev->bus) && dev->bus->iommu_ops->device_group) 342 return dev->bus->iommu_ops->device_group(dev, groupid); 343 344 return -ENODEV; 345 } 346 EXPORT_SYMBOL_GPL(iommu_device_group); 347