drivers/iommu/tegra-gart.c

   1 /*
   2  * IOMMU API for GART in Tegra20
   3  *
   4  * Copyright (c) 2010-2012, NVIDIA CORPORATION.  All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #define pr_fmt(fmt)     "%s(): " fmt, __func__
  21
  22 #include <linux/module.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/slab.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/mm.h>
  28 #include <linux/list.h>
  29 #include <linux/device.h>
  30 #include <linux/io.h>
  31 #include <linux/iommu.h>
  32 #include <linux/of.h>
  33
  34 #include <asm/cacheflush.h>
  35
  36 /* bitmap of the page sizes currently supported */
  37 #define GART_IOMMU_PGSIZES      (SZ_4K)
  38
  39 #define GART_REG_BASE           0x24
  40 #define GART_CONFIG             (0x24 - GART_REG_BASE)
  41 #define GART_ENTRY_ADDR         (0x28 - GART_REG_BASE)
  42 #define GART_ENTRY_DATA         (0x2c - GART_REG_BASE)
  43 #define GART_ENTRY_PHYS_ADDR_VALID      (1 << 31)
  44
  45 #define GART_PAGE_SHIFT         12
  46 #define GART_PAGE_SIZE          (1 << GART_PAGE_SHIFT)
  47 #define GART_PAGE_MASK                                          \
  48         (~(GART_PAGE_SIZE - 1) & ~GART_ENTRY_PHYS_ADDR_VALID)
  49
  50 struct gart_client {
  51         struct device           *dev;
  52         struct list_head        list;
  53 };
  54
  55 struct gart_device {
  56         void __iomem            *regs;
  57         u32                     *savedata;
  58         u32                     page_count;     /* total remappable size */
  59         dma_addr_t              iovmm_base;     /* offset to vmm_area */
  60         spinlock_t              pte_lock;       /* for pagetable */
  61         struct list_head        client;
  62         spinlock_t              client_lock;    /* for client list */
  63         struct device           *dev;
  64 };
  65
  66 struct gart_domain {
  67         struct iommu_domain domain;             /* generic domain handle */
  68         struct gart_device *gart;               /* link to gart device   */
  69 };
  70
  71 static struct gart_device *gart_handle; /* unique for a system */
  72
  73 #define GART_PTE(_pfn)                                          \
  74         (GART_ENTRY_PHYS_ADDR_VALID | ((_pfn) << PAGE_SHIFT))
  75
  76 static struct gart_domain *to_gart_domain(struct iommu_domain *dom)
  77 {
  78         return container_of(dom, struct gart_domain, domain);
  79 }
  80
  81 /*
  82  * Any interaction between any block on PPSB and a block on APB or AHB
  83  * must have these read-back to ensure the APB/AHB bus transaction is
  84  * complete before initiating activity on the PPSB block.
  85  */
  86 #define FLUSH_GART_REGS(gart)   ((void)readl((gart)->regs + GART_CONFIG))
  87
  88 #define for_each_gart_pte(gart, iova)                                   \
  89         for (iova = gart->iovmm_base;                                   \
  90              iova < gart->iovmm_base + GART_PAGE_SIZE * gart->page_count; \
  91              iova += GART_PAGE_SIZE)
  92
  93 static inline void gart_set_pte(struct gart_device *gart,
  94                                 unsigned long offs, u32 pte)
  95 {
  96         writel(offs, gart->regs + GART_ENTRY_ADDR);
  97         writel(pte, gart->regs + GART_ENTRY_DATA);
  98
  99         dev_dbg(gart->dev, "%s %08lx:%08x\n",
 100                  pte ? "map" : "unmap", offs, pte & GART_PAGE_MASK);
 101 }
 102
 103 static inline unsigned long gart_read_pte(struct gart_device *gart,
 104                                           unsigned long offs)
 105 {
 106         unsigned long pte;
 107
 108         writel(offs, gart->regs + GART_ENTRY_ADDR);
 109         pte = readl(gart->regs + GART_ENTRY_DATA);
 110
 111         return pte;
 112 }
 113
 114 static void do_gart_setup(struct gart_device *gart, const u32 *data)
 115 {
 116         unsigned long iova;
 117
 118         for_each_gart_pte(gart, iova)
 119                 gart_set_pte(gart, iova, data ? *(data++) : 0);
 120
 121         writel(1, gart->regs + GART_CONFIG);
 122         FLUSH_GART_REGS(gart);
 123 }
 124
 125 #ifdef DEBUG
 126 static void gart_dump_table(struct gart_device *gart)
 127 {
 128         unsigned long iova;
 129         unsigned long flags;
 130
 131         spin_lock_irqsave(&gart->pte_lock, flags);
 132         for_each_gart_pte(gart, iova) {
 133                 unsigned long pte;
 134
 135                 pte = gart_read_pte(gart, iova);
 136
 137                 dev_dbg(gart->dev, "%s %08lx:%08lx\n",
 138                         (GART_ENTRY_PHYS_ADDR_VALID & pte) ? "v" : " ",
 139                         iova, pte & GART_PAGE_MASK);
 140         }
 141         spin_unlock_irqrestore(&gart->pte_lock, flags);
 142 }
 143 #else
 144 static inline void gart_dump_table(struct gart_device *gart)
 145 {
 146 }
 147 #endif
 148
 149 static inline bool gart_iova_range_valid(struct gart_device *gart,
 150                                          unsigned long iova, size_t bytes)
 151 {
 152         unsigned long iova_start, iova_end, gart_start, gart_end;
 153
 154         iova_start = iova;
 155         iova_end = iova_start + bytes - 1;
 156         gart_start = gart->iovmm_base;
 157         gart_end = gart_start + gart->page_count * GART_PAGE_SIZE - 1;
 158
 159         if (iova_start < gart_start)
 160                 return false;
 161         if (iova_end > gart_end)
 162                 return false;
 163         return true;
 164 }
 165
 166 static int gart_iommu_attach_dev(struct iommu_domain *domain,
 167                                  struct device *dev)
 168 {
 169         struct gart_domain *gart_domain = to_gart_domain(domain);
 170         struct gart_device *gart = gart_domain->gart;
 171         struct gart_client *client, *c;
 172         int err = 0;
 173
 174         client = devm_kzalloc(gart->dev, sizeof(*c), GFP_KERNEL);
 175         if (!client)
 176                 return -ENOMEM;
 177         client->dev = dev;
 178
 179         spin_lock(&gart->client_lock);
 180         list_for_each_entry(c, &gart->client, list) {
 181                 if (c->dev == dev) {
 182                         dev_err(gart->dev,
 183                                 "%s is already attached\n", dev_name(dev));
 184                         err = -EINVAL;
 185                         goto fail;
 186                 }
 187         }
 188         list_add(&client->list, &gart->client);
 189         spin_unlock(&gart->client_lock);
 190         dev_dbg(gart->dev, "Attached %s\n", dev_name(dev));
 191         return 0;
 192
 193 fail:
 194         devm_kfree(gart->dev, client);
 195         spin_unlock(&gart->client_lock);
 196         return err;
 197 }
 198
 199 static void gart_iommu_detach_dev(struct iommu_domain *domain,
 200                                   struct device *dev)
 201 {
 202         struct gart_domain *gart_domain = to_gart_domain(domain);
 203         struct gart_device *gart = gart_domain->gart;
 204         struct gart_client *c;
 205
 206         spin_lock(&gart->client_lock);
 207
 208         list_for_each_entry(c, &gart->client, list) {
 209                 if (c->dev == dev) {
 210                         list_del(&c->list);
 211                         devm_kfree(gart->dev, c);
 212                         dev_dbg(gart->dev, "Detached %s\n", dev_name(dev));
 213                         goto out;
 214                 }
 215         }
 216         dev_err(gart->dev, "Couldn't find\n");
 217 out:
 218         spin_unlock(&gart->client_lock);
 219 }
 220
 221 static struct iommu_domain *gart_iommu_domain_alloc(unsigned type)
 222 {
 223         struct gart_domain *gart_domain;
 224         struct gart_device *gart;
 225
 226         if (type != IOMMU_DOMAIN_UNMANAGED)
 227                 return NULL;
 228
 229         gart = gart_handle;
 230         if (!gart)
 231                 return NULL;
 232
 233         gart_domain = kzalloc(sizeof(*gart_domain), GFP_KERNEL);
 234         if (!gart_domain)
 235                 return NULL;
 236
 237         gart_domain->gart = gart;
 238         gart_domain->domain.geometry.aperture_start = gart->iovmm_base;
 239         gart_domain->domain.geometry.aperture_end = gart->iovmm_base +
 240                                         gart->page_count * GART_PAGE_SIZE - 1;
 241         gart_domain->domain.geometry.force_aperture = true;
 242
 243         return &gart_domain->domain;
 244 }
 245
 246 static void gart_iommu_domain_free(struct iommu_domain *domain)
 247 {
 248         struct gart_domain *gart_domain = to_gart_domain(domain);
 249         struct gart_device *gart = gart_domain->gart;
 250
 251         if (gart) {
 252                 spin_lock(&gart->client_lock);
 253                 if (!list_empty(&gart->client)) {
 254                         struct gart_client *c;
 255
 256                         list_for_each_entry(c, &gart->client, list)
 257                                 gart_iommu_detach_dev(domain, c->dev);
 258                 }
 259                 spin_unlock(&gart->client_lock);
 260         }
 261
 262         kfree(gart_domain);
 263 }
 264
 265 static int gart_iommu_map(struct iommu_domain *domain, unsigned long iova,
 266                           phys_addr_t pa, size_t bytes, int prot)
 267 {
 268         struct gart_domain *gart_domain = to_gart_domain(domain);
 269         struct gart_device *gart = gart_domain->gart;
 270         unsigned long flags;
 271         unsigned long pfn;
 272
 273         if (!gart_iova_range_valid(gart, iova, bytes))
 274                 return -EINVAL;
 275
 276         spin_lock_irqsave(&gart->pte_lock, flags);
 277         pfn = __phys_to_pfn(pa);
 278         if (!pfn_valid(pfn)) {
 279                 dev_err(gart->dev, "Invalid page: %pa\n", &pa);
 280                 spin_unlock_irqrestore(&gart->pte_lock, flags);
 281                 return -EINVAL;
 282         }
 283         gart_set_pte(gart, iova, GART_PTE(pfn));
 284         FLUSH_GART_REGS(gart);
 285         spin_unlock_irqrestore(&gart->pte_lock, flags);
 286         return 0;
 287 }
 288
 289 static size_t gart_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
 290                                size_t bytes)
 291 {
 292         struct gart_domain *gart_domain = to_gart_domain(domain);
 293         struct gart_device *gart = gart_domain->gart;
 294         unsigned long flags;
 295
 296         if (!gart_iova_range_valid(gart, iova, bytes))
 297                 return 0;
 298
 299         spin_lock_irqsave(&gart->pte_lock, flags);
 300         gart_set_pte(gart, iova, 0);
 301         FLUSH_GART_REGS(gart);
 302         spin_unlock_irqrestore(&gart->pte_lock, flags);
 303         return 0;
 304 }
 305
 306 static phys_addr_t gart_iommu_iova_to_phys(struct iommu_domain *domain,
 307                                            dma_addr_t iova)
 308 {
 309         struct gart_domain *gart_domain = to_gart_domain(domain);
 310         struct gart_device *gart = gart_domain->gart;
 311         unsigned long pte;
 312         phys_addr_t pa;
 313         unsigned long flags;
 314
 315         if (!gart_iova_range_valid(gart, iova, 0))
 316                 return -EINVAL;
 317
 318         spin_lock_irqsave(&gart->pte_lock, flags);
 319         pte = gart_read_pte(gart, iova);
 320         spin_unlock_irqrestore(&gart->pte_lock, flags);
 321
 322         pa = (pte & GART_PAGE_MASK);
 323         if (!pfn_valid(__phys_to_pfn(pa))) {
 324                 dev_err(gart->dev, "No entry for %08llx:%pa\n",
 325                          (unsigned long long)iova, &pa);
 326                 gart_dump_table(gart);
 327                 return -EINVAL;
 328         }
 329         return pa;
 330 }
 331
 332 static bool gart_iommu_capable(enum iommu_cap cap)
 333 {
 334         return false;
 335 }
 336
 337 static const struct iommu_ops gart_iommu_ops = {
 338         .capable        = gart_iommu_capable,
 339         .domain_alloc   = gart_iommu_domain_alloc,
 340         .domain_free    = gart_iommu_domain_free,
 341         .attach_dev     = gart_iommu_attach_dev,
 342         .detach_dev     = gart_iommu_detach_dev,
 343         .map            = gart_iommu_map,
 344         .map_sg         = default_iommu_map_sg,
 345         .unmap          = gart_iommu_unmap,
 346         .iova_to_phys   = gart_iommu_iova_to_phys,
 347         .pgsize_bitmap  = GART_IOMMU_PGSIZES,
 348 };
 349
 350 static int tegra_gart_suspend(struct device *dev)
 351 {
 352         struct gart_device *gart = dev_get_drvdata(dev);
 353         unsigned long iova;
 354         u32 *data = gart->savedata;
 355         unsigned long flags;
 356
 357         spin_lock_irqsave(&gart->pte_lock, flags);
 358         for_each_gart_pte(gart, iova)
 359                 *(data++) = gart_read_pte(gart, iova);
 360         spin_unlock_irqrestore(&gart->pte_lock, flags);
 361         return 0;
 362 }
 363
 364 static int tegra_gart_resume(struct device *dev)
 365 {
 366         struct gart_device *gart = dev_get_drvdata(dev);
 367         unsigned long flags;
 368
 369         spin_lock_irqsave(&gart->pte_lock, flags);
 370         do_gart_setup(gart, gart->savedata);
 371         spin_unlock_irqrestore(&gart->pte_lock, flags);
 372         return 0;
 373 }
 374
 375 static int tegra_gart_probe(struct platform_device *pdev)
 376 {
 377         struct gart_device *gart;
 378         struct resource *res, *res_remap;
 379         void __iomem *gart_regs;
 380         struct device *dev = &pdev->dev;
 381
 382         if (gart_handle)
 383                 return -EIO;
 384
 385         BUILD_BUG_ON(PAGE_SHIFT != GART_PAGE_SHIFT);
 386
 387         /* the GART memory aperture is required */
 388         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 389         res_remap = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 390         if (!res || !res_remap) {
 391                 dev_err(dev, "GART memory aperture expected\n");
 392                 return -ENXIO;
 393         }
 394
 395         gart = devm_kzalloc(dev, sizeof(*gart), GFP_KERNEL);
 396         if (!gart) {
 397                 dev_err(dev, "failed to allocate gart_device\n");
 398                 return -ENOMEM;
 399         }
 400
 401         gart_regs = devm_ioremap(dev, res->start, resource_size(res));
 402         if (!gart_regs) {
 403                 dev_err(dev, "failed to remap GART registers\n");
 404                 return -ENXIO;
 405         }
 406
 407         gart->dev = &pdev->dev;
 408         spin_lock_init(&gart->pte_lock);
 409         spin_lock_init(&gart->client_lock);
 410         INIT_LIST_HEAD(&gart->client);
 411         gart->regs = gart_regs;
 412         gart->iovmm_base = (dma_addr_t)res_remap->start;
 413         gart->page_count = (resource_size(res_remap) >> GART_PAGE_SHIFT);
 414
 415         gart->savedata = vmalloc(sizeof(u32) * gart->page_count);
 416         if (!gart->savedata) {
 417                 dev_err(dev, "failed to allocate context save area\n");
 418                 return -ENOMEM;
 419         }
 420
 421         platform_set_drvdata(pdev, gart);
 422         do_gart_setup(gart, NULL);
 423
 424         gart_handle = gart;
 425
 426         return 0;
 427 }
 428
 429 static int tegra_gart_remove(struct platform_device *pdev)
 430 {
 431         struct gart_device *gart = platform_get_drvdata(pdev);
 432
 433         writel(0, gart->regs + GART_CONFIG);
 434         if (gart->savedata)
 435                 vfree(gart->savedata);
 436         gart_handle = NULL;
 437         return 0;
 438 }
 439
 440 static const struct dev_pm_ops tegra_gart_pm_ops = {
 441         .suspend        = tegra_gart_suspend,
 442         .resume         = tegra_gart_resume,
 443 };
 444
 445 static const struct of_device_id tegra_gart_of_match[] = {
 446         { .compatible = "nvidia,tegra20-gart", },
 447         { },
 448 };
 449 MODULE_DEVICE_TABLE(of, tegra_gart_of_match);
 450
 451 static struct platform_driver tegra_gart_driver = {
 452         .probe          = tegra_gart_probe,
 453         .remove         = tegra_gart_remove,
 454         .driver = {
 455                 .name   = "tegra-gart",
 456                 .pm     = &tegra_gart_pm_ops,
 457                 .of_match_table = tegra_gart_of_match,
 458         },
 459 };
 460
 461 static int tegra_gart_init(void)
 462 {
 463         return platform_driver_register(&tegra_gart_driver);
 464 }
 465
 466 static void __exit tegra_gart_exit(void)
 467 {
 468         platform_driver_unregister(&tegra_gart_driver);
 469 }
 470
 471 subsys_initcall(tegra_gart_init);
 472 module_exit(tegra_gart_exit);
 473
 474 MODULE_DESCRIPTION("IOMMU API for GART in Tegra20");
 475 MODULE_AUTHOR("Hiroshi DOYU <hdoyu@nvidia.com>");
 476 MODULE_ALIAS("platform:tegra-gart");
 477 MODULE_LICENSE("GPL v2");