linux/drivers/iommu/shmobile-iommu.c
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   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, 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
 357static 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 = kmalloc(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->attached = NULL;
 391        archdata->ipmmu = ipmmu;
 392        ipmmu_archdata = archdata;
 393        bus_set_iommu(&platform_bus_type, &shmobile_iommu_ops);
 394        return 0;
 395}
 396
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