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 };
  46
  47 static struct shmobile_iommu_archdata *ipmmu_archdata;
  48 static struct kmem_cache *l1cache, *l2cache;
  49
  50 static 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
  61 static 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
  68 static uint32_t pgtable_read(struct shmobile_iommu_domain_pgtable *pgtable,
  69                              unsigned int index)
  70 {
  71         return pgtable->pgtable[index];
  72 }
  73
  74 static 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
  85 static 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
 107 static 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
 121 static 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;
 144 err:
 145         spin_unlock(&archdata->attach_lock);
 146         spin_unlock(&sh_domain->attached_list_lock);
 147         return ret;
 148 }
 149
 150 static 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
 171 static 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
 181 static 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
 196 static void l2realfree(struct shmobile_iommu_domain_pgtable *l2)
 197 {
 198         if (l2->pgtable)
 199                 pgtable_free(l2, l2cache, L2_SIZE);
 200 }
 201
 202 static 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
 213 static 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
 257 static 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);
 291 done:
 292         if (ret)
 293                 domain_tlb_flush(sh_domain);
 294         l2realfree(&l2);
 295         return ret;
 296 }
 297
 298 static 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
 325 static 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
 336 static 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, 0);
 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
 357 static 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
 369 int 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 }