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 * 123 * This function should be used by IOMMU users which want to be notified 124 * whenever an IOMMU fault happens. 125 * 126 * The fault handler itself should return 0 on success, and an appropriate 127 * error code otherwise. 128 */ 129 void iommu_set_fault_handler(struct iommu_domain *domain, 130 iommu_fault_handler_t handler) 131 { 132 BUG_ON(!domain); 133 134 domain->handler = handler; 135 } 136 EXPORT_SYMBOL_GPL(iommu_set_fault_handler); 137 138 struct iommu_domain *iommu_domain_alloc(struct bus_type *bus) 139 { 140 struct iommu_domain *domain; 141 int ret; 142 143 if (bus == NULL || bus->iommu_ops == NULL) 144 return NULL; 145 146 domain = kzalloc(sizeof(*domain), GFP_KERNEL); 147 if (!domain) 148 return NULL; 149 150 domain->ops = bus->iommu_ops; 151 152 ret = domain->ops->domain_init(domain); 153 if (ret) 154 goto out_free; 155 156 return domain; 157 158 out_free: 159 kfree(domain); 160 161 return NULL; 162 } 163 EXPORT_SYMBOL_GPL(iommu_domain_alloc); 164 165 void iommu_domain_free(struct iommu_domain *domain) 166 { 167 if (likely(domain->ops->domain_destroy != NULL)) 168 domain->ops->domain_destroy(domain); 169 170 kfree(domain); 171 } 172 EXPORT_SYMBOL_GPL(iommu_domain_free); 173 174 int iommu_attach_device(struct iommu_domain *domain, struct device *dev) 175 { 176 if (unlikely(domain->ops->attach_dev == NULL)) 177 return -ENODEV; 178 179 return domain->ops->attach_dev(domain, dev); 180 } 181 EXPORT_SYMBOL_GPL(iommu_attach_device); 182 183 void iommu_detach_device(struct iommu_domain *domain, struct device *dev) 184 { 185 if (unlikely(domain->ops->detach_dev == NULL)) 186 return; 187 188 domain->ops->detach_dev(domain, dev); 189 } 190 EXPORT_SYMBOL_GPL(iommu_detach_device); 191 192 phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, 193 unsigned long iova) 194 { 195 if (unlikely(domain->ops->iova_to_phys == NULL)) 196 return 0; 197 198 return domain->ops->iova_to_phys(domain, iova); 199 } 200 EXPORT_SYMBOL_GPL(iommu_iova_to_phys); 201 202 int iommu_domain_has_cap(struct iommu_domain *domain, 203 unsigned long cap) 204 { 205 if (unlikely(domain->ops->domain_has_cap == NULL)) 206 return 0; 207 208 return domain->ops->domain_has_cap(domain, cap); 209 } 210 EXPORT_SYMBOL_GPL(iommu_domain_has_cap); 211 212 int iommu_map(struct iommu_domain *domain, unsigned long iova, 213 phys_addr_t paddr, size_t size, int prot) 214 { 215 unsigned long orig_iova = iova; 216 unsigned int min_pagesz; 217 size_t orig_size = size; 218 int ret = 0; 219 220 if (unlikely(domain->ops->map == NULL)) 221 return -ENODEV; 222 223 /* find out the minimum page size supported */ 224 min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap); 225 226 /* 227 * both the virtual address and the physical one, as well as 228 * the size of the mapping, must be aligned (at least) to the 229 * size of the smallest page supported by the hardware 230 */ 231 if (!IS_ALIGNED(iova | paddr | size, min_pagesz)) { 232 pr_err("unaligned: iova 0x%lx pa 0x%lx size 0x%lx min_pagesz " 233 "0x%x\n", iova, (unsigned long)paddr, 234 (unsigned long)size, min_pagesz); 235 return -EINVAL; 236 } 237 238 pr_debug("map: iova 0x%lx pa 0x%lx size 0x%lx\n", iova, 239 (unsigned long)paddr, (unsigned long)size); 240 241 while (size) { 242 unsigned long pgsize, addr_merge = iova | paddr; 243 unsigned int pgsize_idx; 244 245 /* Max page size that still fits into 'size' */ 246 pgsize_idx = __fls(size); 247 248 /* need to consider alignment requirements ? */ 249 if (likely(addr_merge)) { 250 /* Max page size allowed by both iova and paddr */ 251 unsigned int align_pgsize_idx = __ffs(addr_merge); 252 253 pgsize_idx = min(pgsize_idx, align_pgsize_idx); 254 } 255 256 /* build a mask of acceptable page sizes */ 257 pgsize = (1UL << (pgsize_idx + 1)) - 1; 258 259 /* throw away page sizes not supported by the hardware */ 260 pgsize &= domain->ops->pgsize_bitmap; 261 262 /* make sure we're still sane */ 263 BUG_ON(!pgsize); 264 265 /* pick the biggest page */ 266 pgsize_idx = __fls(pgsize); 267 pgsize = 1UL << pgsize_idx; 268 269 pr_debug("mapping: iova 0x%lx pa 0x%lx pgsize %lu\n", iova, 270 (unsigned long)paddr, pgsize); 271 272 ret = domain->ops->map(domain, iova, paddr, pgsize, prot); 273 if (ret) 274 break; 275 276 iova += pgsize; 277 paddr += pgsize; 278 size -= pgsize; 279 } 280 281 /* unroll mapping in case something went wrong */ 282 if (ret) 283 iommu_unmap(domain, orig_iova, orig_size - size); 284 285 return ret; 286 } 287 EXPORT_SYMBOL_GPL(iommu_map); 288 289 size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) 290 { 291 size_t unmapped_page, unmapped = 0; 292 unsigned int min_pagesz; 293 294 if (unlikely(domain->ops->unmap == NULL)) 295 return -ENODEV; 296 297 /* find out the minimum page size supported */ 298 min_pagesz = 1 << __ffs(domain->ops->pgsize_bitmap); 299 300 /* 301 * The virtual address, as well as the size of the mapping, must be 302 * aligned (at least) to the size of the smallest page supported 303 * by the hardware 304 */ 305 if (!IS_ALIGNED(iova | size, min_pagesz)) { 306 pr_err("unaligned: iova 0x%lx size 0x%lx min_pagesz 0x%x\n", 307 iova, (unsigned long)size, min_pagesz); 308 return -EINVAL; 309 } 310 311 pr_debug("unmap this: iova 0x%lx size 0x%lx\n", iova, 312 (unsigned long)size); 313 314 /* 315 * Keep iterating until we either unmap 'size' bytes (or more) 316 * or we hit an area that isn't mapped. 317 */ 318 while (unmapped < size) { 319 size_t left = size - unmapped; 320 321 unmapped_page = domain->ops->unmap(domain, iova, left); 322 if (!unmapped_page) 323 break; 324 325 pr_debug("unmapped: iova 0x%lx size %lx\n", iova, 326 (unsigned long)unmapped_page); 327 328 iova += unmapped_page; 329 unmapped += unmapped_page; 330 } 331 332 return unmapped; 333 } 334 EXPORT_SYMBOL_GPL(iommu_unmap); 335 336 int iommu_device_group(struct device *dev, unsigned int *groupid) 337 { 338 if (iommu_present(dev->bus) && dev->bus->iommu_ops->device_group) 339 return dev->bus->iommu_ops->device_group(dev, groupid); 340 341 return -ENODEV; 342 } 343 EXPORT_SYMBOL_GPL(iommu_device_group); 344