1/* 2 * IOMMU for IPMMU/IPMMUI 3 * Copyright (C) 2012 Hideki EIRAKU 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; version 2 of the License. 8 */ 9 10#include <linux/dma-mapping.h> 11#include <linux/io.h> 12#include <linux/iommu.h> 13#include <linux/platform_device.h> 14#include <linux/sizes.h> 15#include <linux/slab.h> 16#include <asm/dma-iommu.h> 17#include "shmobile-ipmmu.h" 18 19#define L1_SIZE CONFIG_SHMOBILE_IOMMU_L1SIZE 20#define L1_LEN (L1_SIZE / 4) 21#define L1_ALIGN L1_SIZE 22#define L2_SIZE SZ_1K 23#define L2_LEN (L2_SIZE / 4) 24#define L2_ALIGN L2_SIZE 25 26struct shmobile_iommu_domain_pgtable { 27 uint32_t *pgtable; 28 dma_addr_t handle; 29}; 30 31struct shmobile_iommu_archdata { 32 struct list_head attached_list; 33 struct dma_iommu_mapping *iommu_mapping; 34 spinlock_t attach_lock; 35 struct shmobile_iommu_domain *attached; 36 int num_attached_devices; 37 struct shmobile_ipmmu *ipmmu; 38}; 39 40struct shmobile_iommu_domain { 41 struct shmobile_iommu_domain_pgtable l1, l2[L1_LEN]; 42 spinlock_t map_lock; 43 spinlock_t attached_list_lock; 44 struct list_head attached_list; 45}; 46 47static struct shmobile_iommu_archdata *ipmmu_archdata; 48static struct kmem_cache *l1cache, *l2cache; 49 50static int pgtable_alloc(struct shmobile_iommu_domain_pgtable *pgtable, 51 struct kmem_cache *cache, size_t size) 52{ 53 pgtable->pgtable = kmem_cache_zalloc(cache, GFP_ATOMIC); 54 if (!pgtable->pgtable) 55 return -ENOMEM; 56 pgtable->handle = dma_map_single(NULL, pgtable->pgtable, size, 57 DMA_TO_DEVICE); 58 return 0; 59} 60 61static void pgtable_free(struct shmobile_iommu_domain_pgtable *pgtable, 62 struct kmem_cache *cache, size_t size) 63{ 64 dma_unmap_single(NULL, pgtable->handle, size, DMA_TO_DEVICE); 65 kmem_cache_free(cache, pgtable->pgtable); 66} 67 68static uint32_t pgtable_read(struct shmobile_iommu_domain_pgtable *pgtable, 69 unsigned int index) 70{ 71 return pgtable->pgtable[index]; 72} 73 74static void pgtable_write(struct shmobile_iommu_domain_pgtable *pgtable, 75 unsigned int index, unsigned int count, uint32_t val) 76{ 77 unsigned int i; 78 79 for (i = 0; i < count; i++) 80 pgtable->pgtable[index + i] = val; 81 dma_sync_single_for_device(NULL, pgtable->handle + index * sizeof(val), 82 sizeof(val) * count, DMA_TO_DEVICE); 83} 84 85static int shmobile_iommu_domain_init(struct iommu_domain *domain) 86{ 87 struct shmobile_iommu_domain *sh_domain; 88 int i, ret; 89 90 sh_domain = kmalloc(sizeof(*sh_domain), GFP_KERNEL); 91 if (!sh_domain) 92 return -ENOMEM; 93 ret = pgtable_alloc(&sh_domain->l1, l1cache, L1_SIZE); 94 if (ret < 0) { 95 kfree(sh_domain); 96 return ret; 97 } 98 for (i = 0; i < L1_LEN; i++) 99 sh_domain->l2[i].pgtable = NULL; 100 spin_lock_init(&sh_domain->map_lock); 101 spin_lock_init(&sh_domain->attached_list_lock); 102 INIT_LIST_HEAD(&sh_domain->attached_list); 103 domain->priv = sh_domain; 104 return 0; 105} 106 107static void shmobile_iommu_domain_destroy(struct iommu_domain *domain) 108{ 109 struct shmobile_iommu_domain *sh_domain = domain->priv; 110 int i; 111 112 for (i = 0; i < L1_LEN; i++) { 113 if (sh_domain->l2[i].pgtable) 114 pgtable_free(&sh_domain->l2[i], l2cache, L2_SIZE); 115 } 116 pgtable_free(&sh_domain->l1, l1cache, L1_SIZE); 117 kfree(sh_domain); 118 domain->priv = NULL; 119} 120 121static int shmobile_iommu_attach_device(struct iommu_domain *domain, 122 struct device *dev) 123{ 124 struct shmobile_iommu_archdata *archdata = dev->archdata.iommu; 125 struct shmobile_iommu_domain *sh_domain = domain->priv; 126 int ret = -EBUSY; 127 128 if (!archdata) 129 return -ENODEV; 130 spin_lock(&sh_domain->attached_list_lock); 131 spin_lock(&archdata->attach_lock); 132 if (archdata->attached != sh_domain) { 133 if (archdata->attached) 134 goto err; 135 ipmmu_tlb_set(archdata->ipmmu, sh_domain->l1.handle, L1_SIZE, 136 0); 137 ipmmu_tlb_flush(archdata->ipmmu); 138 archdata->attached = sh_domain; 139 archdata->num_attached_devices = 0; 140 list_add(&archdata->attached_list, &sh_domain->attached_list); 141 } 142 archdata->num_attached_devices++; 143 ret = 0; 144err: 145 spin_unlock(&archdata->attach_lock); 146 spin_unlock(&sh_domain->attached_list_lock); 147 return ret; 148} 149 150static void shmobile_iommu_detach_device(struct iommu_domain *domain, 151 struct device *dev) 152{ 153 struct shmobile_iommu_archdata *archdata = dev->archdata.iommu; 154 struct shmobile_iommu_domain *sh_domain = domain->priv; 155 156 if (!archdata) 157 return; 158 spin_lock(&sh_domain->attached_list_lock); 159 spin_lock(&archdata->attach_lock); 160 archdata->num_attached_devices--; 161 if (!archdata->num_attached_devices) { 162 ipmmu_tlb_set(archdata->ipmmu, 0, 0, 0); 163 ipmmu_tlb_flush(archdata->ipmmu); 164 archdata->attached = NULL; 165 list_del(&archdata->attached_list); 166 } 167 spin_unlock(&archdata->attach_lock); 168 spin_unlock(&sh_domain->attached_list_lock); 169} 170 171static void domain_tlb_flush(struct shmobile_iommu_domain *sh_domain) 172{ 173 struct shmobile_iommu_archdata *archdata; 174 175 spin_lock(&sh_domain->attached_list_lock); 176 list_for_each_entry(archdata, &sh_domain->attached_list, attached_list) 177 ipmmu_tlb_flush(archdata->ipmmu); 178 spin_unlock(&sh_domain->attached_list_lock); 179} 180 181static int l2alloc(struct shmobile_iommu_domain *sh_domain, 182 unsigned int l1index) 183{ 184 int ret; 185 186 if (!sh_domain->l2[l1index].pgtable) { 187 ret = pgtable_alloc(&sh_domain->l2[l1index], l2cache, L2_SIZE); 188 if (ret < 0) 189 return ret; 190 } 191 pgtable_write(&sh_domain->l1, l1index, 1, 192 sh_domain->l2[l1index].handle | 0x1); 193 return 0; 194} 195 196static void l2realfree(struct shmobile_iommu_domain_pgtable *l2) 197{ 198 if (l2->pgtable) 199 pgtable_free(l2, l2cache, L2_SIZE); 200} 201 202static void l2free(struct shmobile_iommu_domain *sh_domain, 203 unsigned int l1index, 204 struct shmobile_iommu_domain_pgtable *l2) 205{ 206 pgtable_write(&sh_domain->l1, l1index, 1, 0); 207 if (sh_domain->l2[l1index].pgtable) { 208 *l2 = sh_domain->l2[l1index]; 209 sh_domain->l2[l1index].pgtable = NULL; 210 } 211} 212 213static int shmobile_iommu_map(struct iommu_domain *domain, unsigned long iova, 214 phys_addr_t paddr, size_t size, int prot) 215{ 216 struct shmobile_iommu_domain_pgtable l2 = { .pgtable = NULL }; 217 struct shmobile_iommu_domain *sh_domain = domain->priv; 218 unsigned int l1index, l2index; 219 int ret; 220 221 l1index = iova >> 20; 222 switch (size) { 223 case SZ_4K: 224 l2index = (iova >> 12) & 0xff; 225 spin_lock(&sh_domain->map_lock); 226 ret = l2alloc(sh_domain, l1index); 227 if (!ret) 228 pgtable_write(&sh_domain->l2[l1index], l2index, 1, 229 paddr | 0xff2); 230 spin_unlock(&sh_domain->map_lock); 231 break; 232 case SZ_64K: 233 l2index = (iova >> 12) & 0xf0; 234 spin_lock(&sh_domain->map_lock); 235 ret = l2alloc(sh_domain, l1index); 236 if (!ret) 237 pgtable_write(&sh_domain->l2[l1index], l2index, 0x10, 238 paddr | 0xff1); 239 spin_unlock(&sh_domain->map_lock); 240 break; 241 case SZ_1M: 242 spin_lock(&sh_domain->map_lock); 243 l2free(sh_domain, l1index, &l2); 244 pgtable_write(&sh_domain->l1, l1index, 1, paddr | 0xc02); 245 spin_unlock(&sh_domain->map_lock); 246 ret = 0; 247 break; 248 default: 249 ret = -EINVAL; 250 } 251 if (!ret) 252 domain_tlb_flush(sh_domain); 253 l2realfree(&l2); 254 return ret; 255} 256 257static size_t shmobile_iommu_unmap(struct iommu_domain *domain, 258 unsigned long iova, size_t size) 259{ 260 struct shmobile_iommu_domain_pgtable l2 = { .pgtable = NULL }; 261 struct shmobile_iommu_domain *sh_domain = domain->priv; 262 unsigned int l1index, l2index; 263 uint32_t l2entry = 0; 264 size_t ret = 0; 265 266 l1index = iova >> 20; 267 if (!(iova & 0xfffff) && size >= SZ_1M) { 268 spin_lock(&sh_domain->map_lock); 269 l2free(sh_domain, l1index, &l2); 270 spin_unlock(&sh_domain->map_lock); 271 ret = SZ_1M; 272 goto done; 273 } 274 l2index = (iova >> 12) & 0xff; 275 spin_lock(&sh_domain->map_lock); 276 if (sh_domain->l2[l1index].pgtable) 277 l2entry = pgtable_read(&sh_domain->l2[l1index], l2index); 278 switch (l2entry & 3) { 279 case 1: 280 if (l2index & 0xf) 281 break; 282 pgtable_write(&sh_domain->l2[l1index], l2index, 0x10, 0); 283 ret = SZ_64K; 284 break; 285 case 2: 286 pgtable_write(&sh_domain->l2[l1index], l2index, 1, 0); 287 ret = SZ_4K; 288 break; 289 } 290 spin_unlock(&sh_domain->map_lock); 291done: 292 if (ret) 293 domain_tlb_flush(sh_domain); 294 l2realfree(&l2); 295 return ret; 296} 297 298static phys_addr_t shmobile_iommu_iova_to_phys(struct iommu_domain *domain, 299 dma_addr_t iova) 300{ 301 struct shmobile_iommu_domain *sh_domain = domain->priv; 302 uint32_t l1entry = 0, l2entry = 0; 303 unsigned int l1index, l2index; 304 305 l1index = iova >> 20; 306 l2index = (iova >> 12) & 0xff; 307 spin_lock(&sh_domain->map_lock); 308 if (sh_domain->l2[l1index].pgtable) 309 l2entry = pgtable_read(&sh_domain->l2[l1index], l2index); 310 else 311 l1entry = pgtable_read(&sh_domain->l1, l1index); 312 spin_unlock(&sh_domain->map_lock); 313 switch (l2entry & 3) { 314 case 1: 315 return (l2entry & ~0xffff) | (iova & 0xffff); 316 case 2: 317 return (l2entry & ~0xfff) | (iova & 0xfff); 318 default: 319 if ((l1entry & 3) == 2) 320 return (l1entry & ~0xfffff) | (iova & 0xfffff); 321 return 0; 322 } 323} 324 325static int find_dev_name(struct shmobile_ipmmu *ipmmu, const char *dev_name) 326{ 327 unsigned int i, n = ipmmu->num_dev_names; 328 329 for (i = 0; i < n; i++) { 330 if (strcmp(ipmmu->dev_names[i], dev_name) == 0) 331 return 1; 332 } 333 return 0; 334} 335 336static int shmobile_iommu_add_device(struct device *dev) 337{ 338 struct shmobile_iommu_archdata *archdata = ipmmu_archdata; 339 struct dma_iommu_mapping *mapping; 340 341 if (!find_dev_name(archdata->ipmmu, dev_name(dev))) 342 return 0; 343 mapping = archdata->iommu_mapping; 344 if (!mapping) { 345 mapping = arm_iommu_create_mapping(&platform_bus_type, 0, 346 L1_LEN << 20); 347 if (IS_ERR(mapping)) 348 return PTR_ERR(mapping); 349 archdata->iommu_mapping = mapping; 350 } 351 dev->archdata.iommu = archdata; 352 if (arm_iommu_attach_device(dev, mapping)) 353 pr_err("arm_iommu_attach_device failed\n"); 354 return 0; 355} 356 357static const struct iommu_ops shmobile_iommu_ops = { 358 .domain_init = shmobile_iommu_domain_init, 359 .domain_destroy = shmobile_iommu_domain_destroy, 360 .attach_dev = shmobile_iommu_attach_device, 361 .detach_dev = shmobile_iommu_detach_device, 362 .map = shmobile_iommu_map, 363 .unmap = shmobile_iommu_unmap, 364 .iova_to_phys = shmobile_iommu_iova_to_phys, 365 .add_device = shmobile_iommu_add_device, 366 .pgsize_bitmap = SZ_1M | SZ_64K | SZ_4K, 367}; 368 369int ipmmu_iommu_init(struct shmobile_ipmmu *ipmmu) 370{ 371 static struct shmobile_iommu_archdata *archdata; 372 373 l1cache = kmem_cache_create("shmobile-iommu-pgtable1", L1_SIZE, 374 L1_ALIGN, SLAB_HWCACHE_ALIGN, NULL); 375 if (!l1cache) 376 return -ENOMEM; 377 l2cache = kmem_cache_create("shmobile-iommu-pgtable2", L2_SIZE, 378 L2_ALIGN, SLAB_HWCACHE_ALIGN, NULL); 379 if (!l2cache) { 380 kmem_cache_destroy(l1cache); 381 return -ENOMEM; 382 } 383 archdata = kzalloc(sizeof(*archdata), GFP_KERNEL); 384 if (!archdata) { 385 kmem_cache_destroy(l1cache); 386 kmem_cache_destroy(l2cache); 387 return -ENOMEM; 388 } 389 spin_lock_init(&archdata->attach_lock); 390 archdata->ipmmu = ipmmu; 391 ipmmu_archdata = archdata; 392 bus_set_iommu(&platform_bus_type, &shmobile_iommu_ops); 393 return 0; 394} 395