kernel/drivers/iommu/shmobile-iommu.c

   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
  26 struct shmobile_iommu_domain_pgtable {
  27         uint32_t *pgtable;
  28         dma_addr_t handle;
  29 };
  30
  31 struct 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
  40 struct 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         struct iommu_domain domain;
  46 };
  47
  48 static struct shmobile_iommu_archdata *ipmmu_archdata;
  49 static struct kmem_cache *l1cache, *l2cache;
  50
  51 static struct shmobile_iommu_domain *to_sh_domain(struct iommu_domain *dom)
  52 {
  53         return container_of(dom, struct shmobile_iommu_domain, domain);
  54 }
  55
  56 static int pgtable_alloc(struct shmobile_iommu_domain_pgtable *pgtable,
  57                          struct kmem_cache *cache, size_t size)
  58 {
  59         pgtable->pgtable = kmem_cache_zalloc(cache, GFP_ATOMIC);
  60         if (!pgtable->pgtable)
  61                 return -ENOMEM;
  62         pgtable->handle = dma_map_single(NULL, pgtable->pgtable, size,
  63                                          DMA_TO_DEVICE);
  64         return 0;
  65 }
  66
  67 static void pgtable_free(struct shmobile_iommu_domain_pgtable *pgtable,
  68                          struct kmem_cache *cache, size_t size)
  69 {
  70         dma_unmap_single(NULL, pgtable->handle, size, DMA_TO_DEVICE);
  71         kmem_cache_free(cache, pgtable->pgtable);
  72 }
  73
  74 static uint32_t pgtable_read(struct shmobile_iommu_domain_pgtable *pgtable,
  75                              unsigned int index)
  76 {
  77         return pgtable->pgtable[index];
  78 }
  79
  80 static void pgtable_write(struct shmobile_iommu_domain_pgtable *pgtable,
  81                           unsigned int index, unsigned int count, uint32_t val)
  82 {
  83         unsigned int i;
  84
  85         for (i = 0; i < count; i++)
  86                 pgtable->pgtable[index + i] = val;
  87         dma_sync_single_for_device(NULL, pgtable->handle + index * sizeof(val),
  88                                    sizeof(val) * count, DMA_TO_DEVICE);
  89 }
  90
  91 static struct iommu_domain *shmobile_iommu_domain_alloc(unsigned type)
  92 {
  93         struct shmobile_iommu_domain *sh_domain;
  94         int i, ret;
  95
  96         if (type != IOMMU_DOMAIN_UNMANAGED)
  97                 return NULL;
  98
  99         sh_domain = kzalloc(sizeof(*sh_domain), GFP_KERNEL);
 100         if (!sh_domain)
 101                 return NULL;
 102         ret = pgtable_alloc(&sh_domain->l1, l1cache, L1_SIZE);
 103         if (ret < 0) {
 104                 kfree(sh_domain);
 105                 return NULL;
 106         }
 107         for (i = 0; i < L1_LEN; i++)
 108                 sh_domain->l2[i].pgtable = NULL;
 109         spin_lock_init(&sh_domain->map_lock);
 110         spin_lock_init(&sh_domain->attached_list_lock);
 111         INIT_LIST_HEAD(&sh_domain->attached_list);
 112         return &sh_domain->domain;
 113 }
 114
 115 static void shmobile_iommu_domain_free(struct iommu_domain *domain)
 116 {
 117         struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
 118         int i;
 119
 120         for (i = 0; i < L1_LEN; i++) {
 121                 if (sh_domain->l2[i].pgtable)
 122                         pgtable_free(&sh_domain->l2[i], l2cache, L2_SIZE);
 123         }
 124         pgtable_free(&sh_domain->l1, l1cache, L1_SIZE);
 125         kfree(sh_domain);
 126 }
 127
 128 static int shmobile_iommu_attach_device(struct iommu_domain *domain,
 129                                         struct device *dev)
 130 {
 131         struct shmobile_iommu_archdata *archdata = dev->archdata.iommu;
 132         struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
 133         int ret = -EBUSY;
 134
 135         if (!archdata)
 136                 return -ENODEV;
 137         spin_lock(&sh_domain->attached_list_lock);
 138         spin_lock(&archdata->attach_lock);
 139         if (archdata->attached != sh_domain) {
 140                 if (archdata->attached)
 141                         goto err;
 142                 ipmmu_tlb_set(archdata->ipmmu, sh_domain->l1.handle, L1_SIZE,
 143                               0);
 144                 ipmmu_tlb_flush(archdata->ipmmu);
 145                 archdata->attached = sh_domain;
 146                 archdata->num_attached_devices = 0;
 147                 list_add(&archdata->attached_list, &sh_domain->attached_list);
 148         }
 149         archdata->num_attached_devices++;
 150         ret = 0;
 151 err:
 152         spin_unlock(&archdata->attach_lock);
 153         spin_unlock(&sh_domain->attached_list_lock);
 154         return ret;
 155 }
 156
 157 static void shmobile_iommu_detach_device(struct iommu_domain *domain,
 158                                          struct device *dev)
 159 {
 160         struct shmobile_iommu_archdata *archdata = dev->archdata.iommu;
 161         struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
 162
 163         if (!archdata)
 164                 return;
 165         spin_lock(&sh_domain->attached_list_lock);
 166         spin_lock(&archdata->attach_lock);
 167         archdata->num_attached_devices--;
 168         if (!archdata->num_attached_devices) {
 169                 ipmmu_tlb_set(archdata->ipmmu, 0, 0, 0);
 170                 ipmmu_tlb_flush(archdata->ipmmu);
 171                 archdata->attached = NULL;
 172                 list_del(&archdata->attached_list);
 173         }
 174         spin_unlock(&archdata->attach_lock);
 175         spin_unlock(&sh_domain->attached_list_lock);
 176 }
 177
 178 static void domain_tlb_flush(struct shmobile_iommu_domain *sh_domain)
 179 {
 180         struct shmobile_iommu_archdata *archdata;
 181
 182         spin_lock(&sh_domain->attached_list_lock);
 183         list_for_each_entry(archdata, &sh_domain->attached_list, attached_list)
 184                 ipmmu_tlb_flush(archdata->ipmmu);
 185         spin_unlock(&sh_domain->attached_list_lock);
 186 }
 187
 188 static int l2alloc(struct shmobile_iommu_domain *sh_domain,
 189                    unsigned int l1index)
 190 {
 191         int ret;
 192
 193         if (!sh_domain->l2[l1index].pgtable) {
 194                 ret = pgtable_alloc(&sh_domain->l2[l1index], l2cache, L2_SIZE);
 195                 if (ret < 0)
 196                         return ret;
 197         }
 198         pgtable_write(&sh_domain->l1, l1index, 1,
 199                       sh_domain->l2[l1index].handle | 0x1);
 200         return 0;
 201 }
 202
 203 static void l2realfree(struct shmobile_iommu_domain_pgtable *l2)
 204 {
 205         if (l2->pgtable)
 206                 pgtable_free(l2, l2cache, L2_SIZE);
 207 }
 208
 209 static void l2free(struct shmobile_iommu_domain *sh_domain,
 210                    unsigned int l1index,
 211                    struct shmobile_iommu_domain_pgtable *l2)
 212 {
 213         pgtable_write(&sh_domain->l1, l1index, 1, 0);
 214         if (sh_domain->l2[l1index].pgtable) {
 215                 *l2 = sh_domain->l2[l1index];
 216                 sh_domain->l2[l1index].pgtable = NULL;
 217         }
 218 }
 219
 220 static int shmobile_iommu_map(struct iommu_domain *domain, unsigned long iova,
 221                               phys_addr_t paddr, size_t size, int prot)
 222 {
 223         struct shmobile_iommu_domain_pgtable l2 = { .pgtable = NULL };
 224         struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
 225         unsigned int l1index, l2index;
 226         int ret;
 227
 228         l1index = iova >> 20;
 229         switch (size) {
 230         case SZ_4K:
 231                 l2index = (iova >> 12) & 0xff;
 232                 spin_lock(&sh_domain->map_lock);
 233                 ret = l2alloc(sh_domain, l1index);
 234                 if (!ret)
 235                         pgtable_write(&sh_domain->l2[l1index], l2index, 1,
 236                                       paddr | 0xff2);
 237                 spin_unlock(&sh_domain->map_lock);
 238                 break;
 239         case SZ_64K:
 240                 l2index = (iova >> 12) & 0xf0;
 241                 spin_lock(&sh_domain->map_lock);
 242                 ret = l2alloc(sh_domain, l1index);
 243                 if (!ret)
 244                         pgtable_write(&sh_domain->l2[l1index], l2index, 0x10,
 245                                       paddr | 0xff1);
 246                 spin_unlock(&sh_domain->map_lock);
 247                 break;
 248         case SZ_1M:
 249                 spin_lock(&sh_domain->map_lock);
 250                 l2free(sh_domain, l1index, &l2);
 251                 pgtable_write(&sh_domain->l1, l1index, 1, paddr | 0xc02);
 252                 spin_unlock(&sh_domain->map_lock);
 253                 ret = 0;
 254                 break;
 255         default:
 256                 ret = -EINVAL;
 257         }
 258         if (!ret)
 259                 domain_tlb_flush(sh_domain);
 260         l2realfree(&l2);
 261         return ret;
 262 }
 263
 264 static size_t shmobile_iommu_unmap(struct iommu_domain *domain,
 265                                    unsigned long iova, size_t size)
 266 {
 267         struct shmobile_iommu_domain_pgtable l2 = { .pgtable = NULL };
 268         struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
 269         unsigned int l1index, l2index;
 270         uint32_t l2entry = 0;
 271         size_t ret = 0;
 272
 273         l1index = iova >> 20;
 274         if (!(iova & 0xfffff) && size >= SZ_1M) {
 275                 spin_lock(&sh_domain->map_lock);
 276                 l2free(sh_domain, l1index, &l2);
 277                 spin_unlock(&sh_domain->map_lock);
 278                 ret = SZ_1M;
 279                 goto done;
 280         }
 281         l2index = (iova >> 12) & 0xff;
 282         spin_lock(&sh_domain->map_lock);
 283         if (sh_domain->l2[l1index].pgtable)
 284                 l2entry = pgtable_read(&sh_domain->l2[l1index], l2index);
 285         switch (l2entry & 3) {
 286         case 1:
 287                 if (l2index & 0xf)
 288                         break;
 289                 pgtable_write(&sh_domain->l2[l1index], l2index, 0x10, 0);
 290                 ret = SZ_64K;
 291                 break;
 292         case 2:
 293                 pgtable_write(&sh_domain->l2[l1index], l2index, 1, 0);
 294                 ret = SZ_4K;
 295                 break;
 296         }
 297         spin_unlock(&sh_domain->map_lock);
 298 done:
 299         if (ret)
 300                 domain_tlb_flush(sh_domain);
 301         l2realfree(&l2);
 302         return ret;
 303 }
 304
 305 static phys_addr_t shmobile_iommu_iova_to_phys(struct iommu_domain *domain,
 306                                                dma_addr_t iova)
 307 {
 308         struct shmobile_iommu_domain *sh_domain = to_sh_domain(domain);
 309         uint32_t l1entry = 0, l2entry = 0;
 310         unsigned int l1index, l2index;
 311
 312         l1index = iova >> 20;
 313         l2index = (iova >> 12) & 0xff;
 314         spin_lock(&sh_domain->map_lock);
 315         if (sh_domain->l2[l1index].pgtable)
 316                 l2entry = pgtable_read(&sh_domain->l2[l1index], l2index);
 317         else
 318                 l1entry = pgtable_read(&sh_domain->l1, l1index);
 319         spin_unlock(&sh_domain->map_lock);
 320         switch (l2entry & 3) {
 321         case 1:
 322                 return (l2entry & ~0xffff) | (iova & 0xffff);
 323         case 2:
 324                 return (l2entry & ~0xfff) | (iova & 0xfff);
 325         default:
 326                 if ((l1entry & 3) == 2)
 327                         return (l1entry & ~0xfffff) | (iova & 0xfffff);
 328                 return 0;
 329         }
 330 }
 331
 332 static int find_dev_name(struct shmobile_ipmmu *ipmmu, const char *dev_name)
 333 {
 334         unsigned int i, n = ipmmu->num_dev_names;
 335
 336         for (i = 0; i < n; i++) {
 337                 if (strcmp(ipmmu->dev_names[i], dev_name) == 0)
 338                         return 1;
 339         }
 340         return 0;
 341 }
 342
 343 static int shmobile_iommu_add_device(struct device *dev)
 344 {
 345         struct shmobile_iommu_archdata *archdata = ipmmu_archdata;
 346         struct dma_iommu_mapping *mapping;
 347
 348         if (!find_dev_name(archdata->ipmmu, dev_name(dev)))
 349                 return 0;
 350         mapping = archdata->iommu_mapping;
 351         if (!mapping) {
 352                 mapping = arm_iommu_create_mapping(&platform_bus_type, 0,
 353                                                    L1_LEN << 20);
 354                 if (IS_ERR(mapping))
 355                         return PTR_ERR(mapping);
 356                 archdata->iommu_mapping = mapping;
 357         }
 358         dev->archdata.iommu = archdata;
 359         if (arm_iommu_attach_device(dev, mapping))
 360                 pr_err("arm_iommu_attach_device failed\n");
 361         return 0;
 362 }
 363
 364 static const struct iommu_ops shmobile_iommu_ops = {
 365         .domain_alloc = shmobile_iommu_domain_alloc,
 366         .domain_free = shmobile_iommu_domain_free,
 367         .attach_dev = shmobile_iommu_attach_device,
 368         .detach_dev = shmobile_iommu_detach_device,
 369         .map = shmobile_iommu_map,
 370         .unmap = shmobile_iommu_unmap,
 371         .map_sg = default_iommu_map_sg,
 372         .iova_to_phys = shmobile_iommu_iova_to_phys,
 373         .add_device = shmobile_iommu_add_device,
 374         .pgsize_bitmap = SZ_1M | SZ_64K | SZ_4K,
 375 };
 376
 377 int ipmmu_iommu_init(struct shmobile_ipmmu *ipmmu)
 378 {
 379         static struct shmobile_iommu_archdata *archdata;
 380
 381         l1cache = kmem_cache_create("shmobile-iommu-pgtable1", L1_SIZE,
 382                                     L1_ALIGN, SLAB_HWCACHE_ALIGN, NULL);
 383         if (!l1cache)
 384                 return -ENOMEM;
 385         l2cache = kmem_cache_create("shmobile-iommu-pgtable2", L2_SIZE,
 386                                     L2_ALIGN, SLAB_HWCACHE_ALIGN, NULL);
 387         if (!l2cache) {
 388                 kmem_cache_destroy(l1cache);
 389                 return -ENOMEM;
 390         }
 391         archdata = kzalloc(sizeof(*archdata), GFP_KERNEL);
 392         if (!archdata) {
 393                 kmem_cache_destroy(l1cache);
 394                 kmem_cache_destroy(l2cache);
 395                 return -ENOMEM;
 396         }
 397         spin_lock_init(&archdata->attach_lock);
 398         archdata->ipmmu = ipmmu;
 399         ipmmu_archdata = archdata;
 400         bus_set_iommu(&platform_bus_type, &shmobile_iommu_ops);
 401         return 0;
 402 }