drivers/iommu/sun50i-iommu.c

   1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2 // Copyright (C) 2016-2018, Allwinner Technology CO., LTD.
   3 // Copyright (C) 2019-2020, Cerno
   4
   5 #include <linux/bitfield.h>
   6 #include <linux/bug.h>
   7 #include <linux/clk.h>
   8 #include <linux/device.h>
   9 #include <linux/dma-direction.h>
  10 #include <linux/dma-iommu.h>
  11 #include <linux/dma-mapping.h>
  12 #include <linux/err.h>
  13 #include <linux/errno.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/iommu.h>
  16 #include <linux/iopoll.h>
  17 #include <linux/ioport.h>
  18 #include <linux/log2.h>
  19 #include <linux/module.h>
  20 #include <linux/of_platform.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/pm.h>
  23 #include <linux/pm_runtime.h>
  24 #include <linux/reset.h>
  25 #include <linux/sizes.h>
  26 #include <linux/slab.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/types.h>
  29
  30 #define IOMMU_RESET_REG                 0x010
  31 #define IOMMU_ENABLE_REG                0x020
  32 #define IOMMU_ENABLE_ENABLE                     BIT(0)
  33
  34 #define IOMMU_BYPASS_REG                0x030
  35 #define IOMMU_AUTO_GATING_REG           0x040
  36 #define IOMMU_AUTO_GATING_ENABLE                BIT(0)
  37
  38 #define IOMMU_WBUF_CTRL_REG             0x044
  39 #define IOMMU_OOO_CTRL_REG              0x048
  40 #define IOMMU_4KB_BDY_PRT_CTRL_REG      0x04c
  41 #define IOMMU_TTB_REG                   0x050
  42 #define IOMMU_TLB_ENABLE_REG            0x060
  43 #define IOMMU_TLB_PREFETCH_REG          0x070
  44 #define IOMMU_TLB_PREFETCH_MASTER_ENABLE(m)     BIT(m)
  45
  46 #define IOMMU_TLB_FLUSH_REG             0x080
  47 #define IOMMU_TLB_FLUSH_PTW_CACHE               BIT(17)
  48 #define IOMMU_TLB_FLUSH_MACRO_TLB               BIT(16)
  49 #define IOMMU_TLB_FLUSH_MICRO_TLB(i)            (BIT(i) & GENMASK(5, 0))
  50
  51 #define IOMMU_TLB_IVLD_ADDR_REG         0x090
  52 #define IOMMU_TLB_IVLD_ADDR_MASK_REG    0x094
  53 #define IOMMU_TLB_IVLD_ENABLE_REG       0x098
  54 #define IOMMU_TLB_IVLD_ENABLE_ENABLE            BIT(0)
  55
  56 #define IOMMU_PC_IVLD_ADDR_REG          0x0a0
  57 #define IOMMU_PC_IVLD_ENABLE_REG        0x0a8
  58 #define IOMMU_PC_IVLD_ENABLE_ENABLE             BIT(0)
  59
  60 #define IOMMU_DM_AUT_CTRL_REG(d)        (0x0b0 + ((d) / 2) * 4)
  61 #define IOMMU_DM_AUT_CTRL_RD_UNAVAIL(d, m)      (1 << (((d & 1) * 16) + ((m) * 2)))
  62 #define IOMMU_DM_AUT_CTRL_WR_UNAVAIL(d, m)      (1 << (((d & 1) * 16) + ((m) * 2) + 1))
  63
  64 #define IOMMU_DM_AUT_OVWT_REG           0x0d0
  65 #define IOMMU_INT_ENABLE_REG            0x100
  66 #define IOMMU_INT_CLR_REG               0x104
  67 #define IOMMU_INT_STA_REG               0x108
  68 #define IOMMU_INT_ERR_ADDR_REG(i)       (0x110 + (i) * 4)
  69 #define IOMMU_INT_ERR_ADDR_L1_REG       0x130
  70 #define IOMMU_INT_ERR_ADDR_L2_REG       0x134
  71 #define IOMMU_INT_ERR_DATA_REG(i)       (0x150 + (i) * 4)
  72 #define IOMMU_L1PG_INT_REG              0x0180
  73 #define IOMMU_L2PG_INT_REG              0x0184
  74
  75 #define IOMMU_INT_INVALID_L2PG                  BIT(17)
  76 #define IOMMU_INT_INVALID_L1PG                  BIT(16)
  77 #define IOMMU_INT_MASTER_PERMISSION(m)          BIT(m)
  78 #define IOMMU_INT_MASTER_MASK                   (IOMMU_INT_MASTER_PERMISSION(0) | \
  79                                                  IOMMU_INT_MASTER_PERMISSION(1) | \
  80                                                  IOMMU_INT_MASTER_PERMISSION(2) | \
  81                                                  IOMMU_INT_MASTER_PERMISSION(3) | \
  82                                                  IOMMU_INT_MASTER_PERMISSION(4) | \
  83                                                  IOMMU_INT_MASTER_PERMISSION(5))
  84 #define IOMMU_INT_MASK                          (IOMMU_INT_INVALID_L1PG | \
  85                                                  IOMMU_INT_INVALID_L2PG | \
  86                                                  IOMMU_INT_MASTER_MASK)
  87
  88 #define PT_ENTRY_SIZE                   sizeof(u32)
  89
  90 #define NUM_DT_ENTRIES                  4096
  91 #define DT_SIZE                         (NUM_DT_ENTRIES * PT_ENTRY_SIZE)
  92
  93 #define NUM_PT_ENTRIES                  256
  94 #define PT_SIZE                         (NUM_PT_ENTRIES * PT_ENTRY_SIZE)
  95
  96 struct sun50i_iommu {
  97         struct iommu_device iommu;
  98
  99         /* Lock to modify the IOMMU registers */
 100         spinlock_t iommu_lock;
 101
 102         struct device *dev;
 103         void __iomem *base;
 104         struct reset_control *reset;
 105         struct clk *clk;
 106
 107         struct iommu_domain *domain;
 108         struct iommu_group *group;
 109         struct kmem_cache *pt_pool;
 110 };
 111
 112 struct sun50i_iommu_domain {
 113         struct iommu_domain domain;
 114
 115         /* Number of devices attached to the domain */
 116         refcount_t refcnt;
 117
 118         /* L1 Page Table */
 119         u32 *dt;
 120         dma_addr_t dt_dma;
 121
 122         struct sun50i_iommu *iommu;
 123 };
 124
 125 static struct sun50i_iommu_domain *to_sun50i_domain(struct iommu_domain *domain)
 126 {
 127         return container_of(domain, struct sun50i_iommu_domain, domain);
 128 }
 129
 130 static struct sun50i_iommu *sun50i_iommu_from_dev(struct device *dev)
 131 {
 132         return dev_iommu_priv_get(dev);
 133 }
 134
 135 static u32 iommu_read(struct sun50i_iommu *iommu, u32 offset)
 136 {
 137         return readl(iommu->base + offset);
 138 }
 139
 140 static void iommu_write(struct sun50i_iommu *iommu, u32 offset, u32 value)
 141 {
 142         writel(value, iommu->base + offset);
 143 }
 144
 145 /*
 146  * The Allwinner H6 IOMMU uses a 2-level page table.
 147  *
 148  * The first level is the usual Directory Table (DT), that consists of
 149  * 4096 4-bytes Directory Table Entries (DTE), each pointing to a Page
 150  * Table (PT).
 151  *
 152  * Each PT consits of 256 4-bytes Page Table Entries (PTE), each
 153  * pointing to a 4kB page of physical memory.
 154  *
 155  * The IOMMU supports a single DT, pointed by the IOMMU_TTB_REG
 156  * register that contains its physical address.
 157  */
 158
 159 #define SUN50I_IOVA_DTE_MASK    GENMASK(31, 20)
 160 #define SUN50I_IOVA_PTE_MASK    GENMASK(19, 12)
 161 #define SUN50I_IOVA_PAGE_MASK   GENMASK(11, 0)
 162
 163 static u32 sun50i_iova_get_dte_index(dma_addr_t iova)
 164 {
 165         return FIELD_GET(SUN50I_IOVA_DTE_MASK, iova);
 166 }
 167
 168 static u32 sun50i_iova_get_pte_index(dma_addr_t iova)
 169 {
 170         return FIELD_GET(SUN50I_IOVA_PTE_MASK, iova);
 171 }
 172
 173 static u32 sun50i_iova_get_page_offset(dma_addr_t iova)
 174 {
 175         return FIELD_GET(SUN50I_IOVA_PAGE_MASK, iova);
 176 }
 177
 178 /*
 179  * Each Directory Table Entry has a Page Table address and a valid
 180  * bit:
 181
 182  * +---------------------+-----------+-+
 183  * | PT address          | Reserved  |V|
 184  * +---------------------+-----------+-+
 185  *  31:10 - Page Table address
 186  *   9:2  - Reserved
 187  *   1:0  - 1 if the entry is valid
 188  */
 189
 190 #define SUN50I_DTE_PT_ADDRESS_MASK      GENMASK(31, 10)
 191 #define SUN50I_DTE_PT_ATTRS             GENMASK(1, 0)
 192 #define SUN50I_DTE_PT_VALID             1
 193
 194 static phys_addr_t sun50i_dte_get_pt_address(u32 dte)
 195 {
 196         return (phys_addr_t)dte & SUN50I_DTE_PT_ADDRESS_MASK;
 197 }
 198
 199 static bool sun50i_dte_is_pt_valid(u32 dte)
 200 {
 201         return (dte & SUN50I_DTE_PT_ATTRS) == SUN50I_DTE_PT_VALID;
 202 }
 203
 204 static u32 sun50i_mk_dte(dma_addr_t pt_dma)
 205 {
 206         return (pt_dma & SUN50I_DTE_PT_ADDRESS_MASK) | SUN50I_DTE_PT_VALID;
 207 }
 208
 209 /*
 210  * Each PTE has a Page address, an authority index and a valid bit:
 211  *
 212  * +----------------+-----+-----+-----+---+-----+
 213  * | Page address   | Rsv | ACI | Rsv | V | Rsv |
 214  * +----------------+-----+-----+-----+---+-----+
 215  *  31:12 - Page address
 216  *  11:8  - Reserved
 217  *   7:4  - Authority Control Index
 218  *   3:2  - Reserved
 219  *     1  - 1 if the entry is valid
 220  *     0  - Reserved
 221  *
 222  * The way permissions work is that the IOMMU has 16 "domains" that
 223  * can be configured to give each masters either read or write
 224  * permissions through the IOMMU_DM_AUT_CTRL_REG registers. The domain
 225  * 0 seems like the default domain, and its permissions in the
 226  * IOMMU_DM_AUT_CTRL_REG are only read-only, so it's not really
 227  * useful to enforce any particular permission.
 228  *
 229  * Each page entry will then have a reference to the domain they are
 230  * affected to, so that we can actually enforce them on a per-page
 231  * basis.
 232  *
 233  * In order to make it work with the IOMMU framework, we will be using
 234  * 4 different domains, starting at 1: RD_WR, RD, WR and NONE
 235  * depending on the permission we want to enforce. Each domain will
 236  * have each master setup in the same way, since the IOMMU framework
 237  * doesn't seem to restrict page access on a per-device basis. And
 238  * then we will use the relevant domain index when generating the page
 239  * table entry depending on the permissions we want to be enforced.
 240  */
 241
 242 enum sun50i_iommu_aci {
 243         SUN50I_IOMMU_ACI_DO_NOT_USE = 0,
 244         SUN50I_IOMMU_ACI_NONE,
 245         SUN50I_IOMMU_ACI_RD,
 246         SUN50I_IOMMU_ACI_WR,
 247         SUN50I_IOMMU_ACI_RD_WR,
 248 };
 249
 250 #define SUN50I_PTE_PAGE_ADDRESS_MASK    GENMASK(31, 12)
 251 #define SUN50I_PTE_ACI_MASK             GENMASK(7, 4)
 252 #define SUN50I_PTE_PAGE_VALID           BIT(1)
 253
 254 static phys_addr_t sun50i_pte_get_page_address(u32 pte)
 255 {
 256         return (phys_addr_t)pte & SUN50I_PTE_PAGE_ADDRESS_MASK;
 257 }
 258
 259 static enum sun50i_iommu_aci sun50i_get_pte_aci(u32 pte)
 260 {
 261         return FIELD_GET(SUN50I_PTE_ACI_MASK, pte);
 262 }
 263
 264 static bool sun50i_pte_is_page_valid(u32 pte)
 265 {
 266         return pte & SUN50I_PTE_PAGE_VALID;
 267 }
 268
 269 static u32 sun50i_mk_pte(phys_addr_t page, int prot)
 270 {
 271         enum sun50i_iommu_aci aci;
 272         u32 flags = 0;
 273
 274         if (prot & (IOMMU_READ | IOMMU_WRITE))
 275                 aci = SUN50I_IOMMU_ACI_RD_WR;
 276         else if (prot & IOMMU_READ)
 277                 aci = SUN50I_IOMMU_ACI_RD;
 278         else if (prot & IOMMU_WRITE)
 279                 aci = SUN50I_IOMMU_ACI_WR;
 280         else
 281                 aci = SUN50I_IOMMU_ACI_NONE;
 282
 283         flags |= FIELD_PREP(SUN50I_PTE_ACI_MASK, aci);
 284         page &= SUN50I_PTE_PAGE_ADDRESS_MASK;
 285         return page | flags | SUN50I_PTE_PAGE_VALID;
 286 }
 287
 288 static void sun50i_table_flush(struct sun50i_iommu_domain *sun50i_domain,
 289                                void *vaddr, unsigned int count)
 290 {
 291         struct sun50i_iommu *iommu = sun50i_domain->iommu;
 292         dma_addr_t dma = virt_to_phys(vaddr);
 293         size_t size = count * PT_ENTRY_SIZE;
 294
 295         dma_sync_single_for_device(iommu->dev, dma, size, DMA_TO_DEVICE);
 296 }
 297
 298 static int sun50i_iommu_flush_all_tlb(struct sun50i_iommu *iommu)
 299 {
 300         u32 reg;
 301         int ret;
 302
 303         assert_spin_locked(&iommu->iommu_lock);
 304
 305         iommu_write(iommu,
 306                     IOMMU_TLB_FLUSH_REG,
 307                     IOMMU_TLB_FLUSH_PTW_CACHE |
 308                     IOMMU_TLB_FLUSH_MACRO_TLB |
 309                     IOMMU_TLB_FLUSH_MICRO_TLB(5) |
 310                     IOMMU_TLB_FLUSH_MICRO_TLB(4) |
 311                     IOMMU_TLB_FLUSH_MICRO_TLB(3) |
 312                     IOMMU_TLB_FLUSH_MICRO_TLB(2) |
 313                     IOMMU_TLB_FLUSH_MICRO_TLB(1) |
 314                     IOMMU_TLB_FLUSH_MICRO_TLB(0));
 315
 316         ret = readl_poll_timeout_atomic(iommu->base + IOMMU_TLB_FLUSH_REG,
 317                                         reg, !reg,
 318                                         1, 2000);
 319         if (ret)
 320                 dev_warn(iommu->dev, "TLB Flush timed out!\n");
 321
 322         return ret;
 323 }
 324
 325 static void sun50i_iommu_flush_iotlb_all(struct iommu_domain *domain)
 326 {
 327         struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
 328         struct sun50i_iommu *iommu = sun50i_domain->iommu;
 329         unsigned long flags;
 330
 331         /*
 332          * At boot, we'll have a first call into .flush_iotlb_all right after
 333          * .probe_device, and since we link our (single) domain to our iommu in
 334          * the .attach_device callback, we don't have that pointer set.
 335          *
 336          * It shouldn't really be any trouble to ignore it though since we flush
 337          * all caches as part of the device powerup.
 338          */
 339         if (!iommu)
 340                 return;
 341
 342         spin_lock_irqsave(&iommu->iommu_lock, flags);
 343         sun50i_iommu_flush_all_tlb(iommu);
 344         spin_unlock_irqrestore(&iommu->iommu_lock, flags);
 345 }
 346
 347 static void sun50i_iommu_iotlb_sync(struct iommu_domain *domain,
 348                                     struct iommu_iotlb_gather *gather)
 349 {
 350         sun50i_iommu_flush_iotlb_all(domain);
 351 }
 352
 353 static int sun50i_iommu_enable(struct sun50i_iommu *iommu)
 354 {
 355         struct sun50i_iommu_domain *sun50i_domain;
 356         unsigned long flags;
 357         int ret;
 358
 359         if (!iommu->domain)
 360                 return 0;
 361
 362         sun50i_domain = to_sun50i_domain(iommu->domain);
 363
 364         ret = reset_control_deassert(iommu->reset);
 365         if (ret)
 366                 return ret;
 367
 368         ret = clk_prepare_enable(iommu->clk);
 369         if (ret)
 370                 goto err_reset_assert;
 371
 372         spin_lock_irqsave(&iommu->iommu_lock, flags);
 373
 374         iommu_write(iommu, IOMMU_TTB_REG, sun50i_domain->dt_dma);
 375         iommu_write(iommu, IOMMU_TLB_PREFETCH_REG,
 376                     IOMMU_TLB_PREFETCH_MASTER_ENABLE(0) |
 377                     IOMMU_TLB_PREFETCH_MASTER_ENABLE(1) |
 378                     IOMMU_TLB_PREFETCH_MASTER_ENABLE(2) |
 379                     IOMMU_TLB_PREFETCH_MASTER_ENABLE(3) |
 380                     IOMMU_TLB_PREFETCH_MASTER_ENABLE(4) |
 381                     IOMMU_TLB_PREFETCH_MASTER_ENABLE(5));
 382         iommu_write(iommu, IOMMU_INT_ENABLE_REG, IOMMU_INT_MASK);
 383         iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_NONE),
 384                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |
 385                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 0) |
 386                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 1) |
 387                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 1) |
 388                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 2) |
 389                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 2) |
 390                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 3) |
 391                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 3) |
 392                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 4) |
 393                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 4) |
 394                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 5) |
 395                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_NONE, 5));
 396
 397         iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_RD),
 398                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 0) |
 399                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 1) |
 400                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 2) |
 401                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 3) |
 402                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 4) |
 403                     IOMMU_DM_AUT_CTRL_WR_UNAVAIL(SUN50I_IOMMU_ACI_RD, 5));
 404
 405         iommu_write(iommu, IOMMU_DM_AUT_CTRL_REG(SUN50I_IOMMU_ACI_WR),
 406                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 0) |
 407                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 1) |
 408                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 2) |
 409                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 3) |
 410                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 4) |
 411                     IOMMU_DM_AUT_CTRL_RD_UNAVAIL(SUN50I_IOMMU_ACI_WR, 5));
 412
 413         ret = sun50i_iommu_flush_all_tlb(iommu);
 414         if (ret) {
 415                 spin_unlock_irqrestore(&iommu->iommu_lock, flags);
 416                 goto err_clk_disable;
 417         }
 418
 419         iommu_write(iommu, IOMMU_AUTO_GATING_REG, IOMMU_AUTO_GATING_ENABLE);
 420         iommu_write(iommu, IOMMU_ENABLE_REG, IOMMU_ENABLE_ENABLE);
 421
 422         spin_unlock_irqrestore(&iommu->iommu_lock, flags);
 423
 424         return 0;
 425
 426 err_clk_disable:
 427         clk_disable_unprepare(iommu->clk);
 428
 429 err_reset_assert:
 430         reset_control_assert(iommu->reset);
 431
 432         return ret;
 433 }
 434
 435 static void sun50i_iommu_disable(struct sun50i_iommu *iommu)
 436 {
 437         unsigned long flags;
 438
 439         spin_lock_irqsave(&iommu->iommu_lock, flags);
 440
 441         iommu_write(iommu, IOMMU_ENABLE_REG, 0);
 442         iommu_write(iommu, IOMMU_TTB_REG, 0);
 443
 444         spin_unlock_irqrestore(&iommu->iommu_lock, flags);
 445
 446         clk_disable_unprepare(iommu->clk);
 447         reset_control_assert(iommu->reset);
 448 }
 449
 450 static void *sun50i_iommu_alloc_page_table(struct sun50i_iommu *iommu,
 451                                            gfp_t gfp)
 452 {
 453         dma_addr_t pt_dma;
 454         u32 *page_table;
 455
 456         page_table = kmem_cache_zalloc(iommu->pt_pool, gfp);
 457         if (!page_table)
 458                 return ERR_PTR(-ENOMEM);
 459
 460         pt_dma = dma_map_single(iommu->dev, page_table, PT_SIZE, DMA_TO_DEVICE);
 461         if (dma_mapping_error(iommu->dev, pt_dma)) {
 462                 dev_err(iommu->dev, "Couldn't map L2 Page Table\n");
 463                 kmem_cache_free(iommu->pt_pool, page_table);
 464                 return ERR_PTR(-ENOMEM);
 465         }
 466
 467         /* We rely on the physical address and DMA address being the same */
 468         WARN_ON(pt_dma != virt_to_phys(page_table));
 469
 470         return page_table;
 471 }
 472
 473 static void sun50i_iommu_free_page_table(struct sun50i_iommu *iommu,
 474                                          u32 *page_table)
 475 {
 476         phys_addr_t pt_phys = virt_to_phys(page_table);
 477
 478         dma_unmap_single(iommu->dev, pt_phys, PT_SIZE, DMA_TO_DEVICE);
 479         kmem_cache_free(iommu->pt_pool, page_table);
 480 }
 481
 482 static u32 *sun50i_dte_get_page_table(struct sun50i_iommu_domain *sun50i_domain,
 483                                       dma_addr_t iova, gfp_t gfp)
 484 {
 485         struct sun50i_iommu *iommu = sun50i_domain->iommu;
 486         u32 *page_table;
 487         u32 *dte_addr;
 488         u32 old_dte;
 489         u32 dte;
 490
 491         dte_addr = &sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
 492         dte = *dte_addr;
 493         if (sun50i_dte_is_pt_valid(dte)) {
 494                 phys_addr_t pt_phys = sun50i_dte_get_pt_address(dte);
 495                 return (u32 *)phys_to_virt(pt_phys);
 496         }
 497
 498         page_table = sun50i_iommu_alloc_page_table(iommu, gfp);
 499         if (IS_ERR(page_table))
 500                 return page_table;
 501
 502         dte = sun50i_mk_dte(virt_to_phys(page_table));
 503         old_dte = cmpxchg(dte_addr, 0, dte);
 504         if (old_dte) {
 505                 phys_addr_t installed_pt_phys =
 506                         sun50i_dte_get_pt_address(old_dte);
 507                 u32 *installed_pt = phys_to_virt(installed_pt_phys);
 508                 u32 *drop_pt = page_table;
 509
 510                 page_table = installed_pt;
 511                 dte = old_dte;
 512                 sun50i_iommu_free_page_table(iommu, drop_pt);
 513         }
 514
 515         sun50i_table_flush(sun50i_domain, page_table, PT_SIZE);
 516         sun50i_table_flush(sun50i_domain, dte_addr, 1);
 517
 518         return page_table;
 519 }
 520
 521 static int sun50i_iommu_map(struct iommu_domain *domain, unsigned long iova,
 522                             phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
 523 {
 524         struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
 525         struct sun50i_iommu *iommu = sun50i_domain->iommu;
 526         u32 pte_index;
 527         u32 *page_table, *pte_addr;
 528         int ret = 0;
 529
 530         page_table = sun50i_dte_get_page_table(sun50i_domain, iova, gfp);
 531         if (IS_ERR(page_table)) {
 532                 ret = PTR_ERR(page_table);
 533                 goto out;
 534         }
 535
 536         pte_index = sun50i_iova_get_pte_index(iova);
 537         pte_addr = &page_table[pte_index];
 538         if (unlikely(sun50i_pte_is_page_valid(*pte_addr))) {
 539                 phys_addr_t page_phys = sun50i_pte_get_page_address(*pte_addr);
 540                 dev_err(iommu->dev,
 541                         "iova %pad already mapped to %pa cannot remap to %pa prot: %#x\n",
 542                         &iova, &page_phys, &paddr, prot);
 543                 ret = -EBUSY;
 544                 goto out;
 545         }
 546
 547         *pte_addr = sun50i_mk_pte(paddr, prot);
 548         sun50i_table_flush(sun50i_domain, pte_addr, 1);
 549
 550 out:
 551         return ret;
 552 }
 553
 554 static size_t sun50i_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
 555                                  size_t size, struct iommu_iotlb_gather *gather)
 556 {
 557         struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
 558         phys_addr_t pt_phys;
 559         u32 *pte_addr;
 560         u32 dte;
 561
 562         dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
 563         if (!sun50i_dte_is_pt_valid(dte))
 564                 return 0;
 565
 566         pt_phys = sun50i_dte_get_pt_address(dte);
 567         pte_addr = (u32 *)phys_to_virt(pt_phys) + sun50i_iova_get_pte_index(iova);
 568
 569         if (!sun50i_pte_is_page_valid(*pte_addr))
 570                 return 0;
 571
 572         memset(pte_addr, 0, sizeof(*pte_addr));
 573         sun50i_table_flush(sun50i_domain, pte_addr, 1);
 574
 575         return SZ_4K;
 576 }
 577
 578 static phys_addr_t sun50i_iommu_iova_to_phys(struct iommu_domain *domain,
 579                                              dma_addr_t iova)
 580 {
 581         struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
 582         phys_addr_t pt_phys;
 583         u32 *page_table;
 584         u32 dte, pte;
 585
 586         dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
 587         if (!sun50i_dte_is_pt_valid(dte))
 588                 return 0;
 589
 590         pt_phys = sun50i_dte_get_pt_address(dte);
 591         page_table = (u32 *)phys_to_virt(pt_phys);
 592         pte = page_table[sun50i_iova_get_pte_index(iova)];
 593         if (!sun50i_pte_is_page_valid(pte))
 594                 return 0;
 595
 596         return sun50i_pte_get_page_address(pte) +
 597                 sun50i_iova_get_page_offset(iova);
 598 }
 599
 600 static struct iommu_domain *sun50i_iommu_domain_alloc(unsigned type)
 601 {
 602         struct sun50i_iommu_domain *sun50i_domain;
 603
 604         if (type != IOMMU_DOMAIN_DMA &&
 605             type != IOMMU_DOMAIN_IDENTITY &&
 606             type != IOMMU_DOMAIN_UNMANAGED)
 607                 return NULL;
 608
 609         sun50i_domain = kzalloc(sizeof(*sun50i_domain), GFP_KERNEL);
 610         if (!sun50i_domain)
 611                 return NULL;
 612
 613         if (type == IOMMU_DOMAIN_DMA &&
 614             iommu_get_dma_cookie(&sun50i_domain->domain))
 615                 goto err_free_domain;
 616
 617         sun50i_domain->dt = (u32 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
 618                                                     get_order(DT_SIZE));
 619         if (!sun50i_domain->dt)
 620                 goto err_put_cookie;
 621
 622         refcount_set(&sun50i_domain->refcnt, 1);
 623
 624         sun50i_domain->domain.geometry.aperture_start = 0;
 625         sun50i_domain->domain.geometry.aperture_end = DMA_BIT_MASK(32);
 626         sun50i_domain->domain.geometry.force_aperture = true;
 627
 628         return &sun50i_domain->domain;
 629
 630 err_put_cookie:
 631         if (type == IOMMU_DOMAIN_DMA)
 632                 iommu_put_dma_cookie(&sun50i_domain->domain);
 633
 634 err_free_domain:
 635         kfree(sun50i_domain);
 636
 637         return NULL;
 638 }
 639
 640 static void sun50i_iommu_domain_free(struct iommu_domain *domain)
 641 {
 642         struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
 643
 644         free_pages((unsigned long)sun50i_domain->dt, get_order(DT_SIZE));
 645         sun50i_domain->dt = NULL;
 646
 647         iommu_put_dma_cookie(domain);
 648
 649         kfree(sun50i_domain);
 650 }
 651
 652 static int sun50i_iommu_attach_domain(struct sun50i_iommu *iommu,
 653                                       struct sun50i_iommu_domain *sun50i_domain)
 654 {
 655         iommu->domain = &sun50i_domain->domain;
 656         sun50i_domain->iommu = iommu;
 657
 658         sun50i_domain->dt_dma = dma_map_single(iommu->dev, sun50i_domain->dt,
 659                                                DT_SIZE, DMA_TO_DEVICE);
 660         if (dma_mapping_error(iommu->dev, sun50i_domain->dt_dma)) {
 661                 dev_err(iommu->dev, "Couldn't map L1 Page Table\n");
 662                 return -ENOMEM;
 663         }
 664
 665         return sun50i_iommu_enable(iommu);
 666 }
 667
 668 static void sun50i_iommu_detach_domain(struct sun50i_iommu *iommu,
 669                                        struct sun50i_iommu_domain *sun50i_domain)
 670 {
 671         unsigned int i;
 672
 673         for (i = 0; i < NUM_DT_ENTRIES; i++) {
 674                 phys_addr_t pt_phys;
 675                 u32 *page_table;
 676                 u32 *dte_addr;
 677                 u32 dte;
 678
 679                 dte_addr = &sun50i_domain->dt[i];
 680                 dte = *dte_addr;
 681                 if (!sun50i_dte_is_pt_valid(dte))
 682                         continue;
 683
 684                 memset(dte_addr, 0, sizeof(*dte_addr));
 685                 sun50i_table_flush(sun50i_domain, dte_addr, 1);
 686
 687                 pt_phys = sun50i_dte_get_pt_address(dte);
 688                 page_table = phys_to_virt(pt_phys);
 689                 sun50i_iommu_free_page_table(iommu, page_table);
 690         }
 691
 692
 693         sun50i_iommu_disable(iommu);
 694
 695         dma_unmap_single(iommu->dev, virt_to_phys(sun50i_domain->dt),
 696                          DT_SIZE, DMA_TO_DEVICE);
 697
 698         iommu->domain = NULL;
 699 }
 700
 701 static void sun50i_iommu_detach_device(struct iommu_domain *domain,
 702                                        struct device *dev)
 703 {
 704         struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
 705         struct sun50i_iommu *iommu = dev_iommu_priv_get(dev);
 706
 707         dev_dbg(dev, "Detaching from IOMMU domain\n");
 708
 709         if (iommu->domain != domain)
 710                 return;
 711
 712         if (refcount_dec_and_test(&sun50i_domain->refcnt))
 713                 sun50i_iommu_detach_domain(iommu, sun50i_domain);
 714 }
 715
 716 static int sun50i_iommu_attach_device(struct iommu_domain *domain,
 717                                       struct device *dev)
 718 {
 719         struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain);
 720         struct sun50i_iommu *iommu;
 721
 722         iommu = sun50i_iommu_from_dev(dev);
 723         if (!iommu)
 724                 return -ENODEV;
 725
 726         dev_dbg(dev, "Attaching to IOMMU domain\n");
 727
 728         refcount_inc(&sun50i_domain->refcnt);
 729
 730         if (iommu->domain == domain)
 731                 return 0;
 732
 733         if (iommu->domain)
 734                 sun50i_iommu_detach_device(iommu->domain, dev);
 735
 736         sun50i_iommu_attach_domain(iommu, sun50i_domain);
 737
 738         return 0;
 739 }
 740
 741 static struct iommu_device *sun50i_iommu_probe_device(struct device *dev)
 742 {
 743         struct sun50i_iommu *iommu;
 744
 745         iommu = sun50i_iommu_from_dev(dev);
 746         if (!iommu)
 747                 return ERR_PTR(-ENODEV);
 748
 749         return &iommu->iommu;
 750 }
 751
 752 static void sun50i_iommu_release_device(struct device *dev) {}
 753
 754 static struct iommu_group *sun50i_iommu_device_group(struct device *dev)
 755 {
 756         struct sun50i_iommu *iommu = sun50i_iommu_from_dev(dev);
 757
 758         return iommu_group_ref_get(iommu->group);
 759 }
 760
 761 static int sun50i_iommu_of_xlate(struct device *dev,
 762                                  struct of_phandle_args *args)
 763 {
 764         struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
 765         unsigned id = args->args[0];
 766
 767         dev_iommu_priv_set(dev, platform_get_drvdata(iommu_pdev));
 768
 769         return iommu_fwspec_add_ids(dev, &id, 1);
 770 }
 771
 772 static const struct iommu_ops sun50i_iommu_ops = {
 773         .pgsize_bitmap  = SZ_4K,
 774         .attach_dev     = sun50i_iommu_attach_device,
 775         .detach_dev     = sun50i_iommu_detach_device,
 776         .device_group   = sun50i_iommu_device_group,
 777         .domain_alloc   = sun50i_iommu_domain_alloc,
 778         .domain_free    = sun50i_iommu_domain_free,
 779         .flush_iotlb_all = sun50i_iommu_flush_iotlb_all,
 780         .iotlb_sync     = sun50i_iommu_iotlb_sync,
 781         .iova_to_phys   = sun50i_iommu_iova_to_phys,
 782         .map            = sun50i_iommu_map,
 783         .of_xlate       = sun50i_iommu_of_xlate,
 784         .probe_device   = sun50i_iommu_probe_device,
 785         .release_device = sun50i_iommu_release_device,
 786         .unmap          = sun50i_iommu_unmap,
 787 };
 788
 789 static void sun50i_iommu_report_fault(struct sun50i_iommu *iommu,
 790                                       unsigned master, phys_addr_t iova,
 791                                       unsigned prot)
 792 {
 793         dev_err(iommu->dev, "Page fault for %pad (master %d, dir %s)\n",
 794                 &iova, master, (prot == IOMMU_FAULT_WRITE) ? "wr" : "rd");
 795
 796         if (iommu->domain)
 797                 report_iommu_fault(iommu->domain, iommu->dev, iova, prot);
 798         else
 799                 dev_err(iommu->dev, "Page fault while iommu not attached to any domain?\n");
 800 }
 801
 802 static phys_addr_t sun50i_iommu_handle_pt_irq(struct sun50i_iommu *iommu,
 803                                               unsigned addr_reg,
 804                                               unsigned blame_reg)
 805 {
 806         phys_addr_t iova;
 807         unsigned master;
 808         u32 blame;
 809
 810         assert_spin_locked(&iommu->iommu_lock);
 811
 812         iova = iommu_read(iommu, addr_reg);
 813         blame = iommu_read(iommu, blame_reg);
 814         master = ilog2(blame & IOMMU_INT_MASTER_MASK);
 815
 816         /*
 817          * If the address is not in the page table, we can't get what
 818          * operation triggered the fault. Assume it's a read
 819          * operation.
 820          */
 821         sun50i_iommu_report_fault(iommu, master, iova, IOMMU_FAULT_READ);
 822
 823         return iova;
 824 }
 825
 826 static phys_addr_t sun50i_iommu_handle_perm_irq(struct sun50i_iommu *iommu)
 827 {
 828         enum sun50i_iommu_aci aci;
 829         phys_addr_t iova;
 830         unsigned master;
 831         unsigned dir;
 832         u32 blame;
 833
 834         assert_spin_locked(&iommu->iommu_lock);
 835
 836         blame = iommu_read(iommu, IOMMU_INT_STA_REG);
 837         master = ilog2(blame & IOMMU_INT_MASTER_MASK);
 838         iova = iommu_read(iommu, IOMMU_INT_ERR_ADDR_REG(master));
 839         aci = sun50i_get_pte_aci(iommu_read(iommu,
 840                                             IOMMU_INT_ERR_DATA_REG(master)));
 841
 842         switch (aci) {
 843                 /*
 844                  * If we are in the read-only domain, then it means we
 845                  * tried to write.
 846                  */
 847         case SUN50I_IOMMU_ACI_RD:
 848                 dir = IOMMU_FAULT_WRITE;
 849                 break;
 850
 851                 /*
 852                  * If we are in the write-only domain, then it means
 853                  * we tried to read.
 854                  */
 855         case SUN50I_IOMMU_ACI_WR:
 856
 857                 /*
 858                  * If we are in the domain without any permission, we
 859                  * can't really tell. Let's default to a read
 860                  * operation.
 861                  */
 862         case SUN50I_IOMMU_ACI_NONE:
 863
 864                 /* WTF? */
 865         case SUN50I_IOMMU_ACI_RD_WR:
 866         default:
 867                 dir = IOMMU_FAULT_READ;
 868                 break;
 869         }
 870
 871         /*
 872          * If the address is not in the page table, we can't get what
 873          * operation triggered the fault. Assume it's a read
 874          * operation.
 875          */
 876         sun50i_iommu_report_fault(iommu, master, iova, dir);
 877
 878         return iova;
 879 }
 880
 881 static irqreturn_t sun50i_iommu_irq(int irq, void *dev_id)
 882 {
 883         struct sun50i_iommu *iommu = dev_id;
 884         phys_addr_t iova;
 885         u32 status;
 886
 887         spin_lock(&iommu->iommu_lock);
 888
 889         status = iommu_read(iommu, IOMMU_INT_STA_REG);
 890         if (!(status & IOMMU_INT_MASK)) {
 891                 spin_unlock(&iommu->iommu_lock);
 892                 return IRQ_NONE;
 893         }
 894
 895         if (status & IOMMU_INT_INVALID_L2PG)
 896                 iova = sun50i_iommu_handle_pt_irq(iommu,
 897                                                   IOMMU_INT_ERR_ADDR_L2_REG,
 898                                                   IOMMU_L2PG_INT_REG);
 899         else if (status & IOMMU_INT_INVALID_L1PG)
 900                 iova = sun50i_iommu_handle_pt_irq(iommu,
 901                                                   IOMMU_INT_ERR_ADDR_L1_REG,
 902                                                   IOMMU_L1PG_INT_REG);
 903         else
 904                 iova = sun50i_iommu_handle_perm_irq(iommu);
 905
 906         iommu_write(iommu, IOMMU_INT_CLR_REG, status);
 907
 908         iommu_write(iommu, IOMMU_RESET_REG, ~status);
 909         iommu_write(iommu, IOMMU_RESET_REG, status);
 910
 911         spin_unlock(&iommu->iommu_lock);
 912
 913         return IRQ_HANDLED;
 914 }
 915
 916 static int sun50i_iommu_probe(struct platform_device *pdev)
 917 {
 918         struct sun50i_iommu *iommu;
 919         int ret, irq;
 920
 921         iommu = devm_kzalloc(&pdev->dev, sizeof(*iommu), GFP_KERNEL);
 922         if (!iommu)
 923                 return -ENOMEM;
 924         spin_lock_init(&iommu->iommu_lock);
 925         platform_set_drvdata(pdev, iommu);
 926         iommu->dev = &pdev->dev;
 927
 928         iommu->pt_pool = kmem_cache_create(dev_name(&pdev->dev),
 929                                            PT_SIZE, PT_SIZE,
 930                                            SLAB_HWCACHE_ALIGN,
 931                                            NULL);
 932         if (!iommu->pt_pool)
 933                 return -ENOMEM;
 934
 935         iommu->group = iommu_group_alloc();
 936         if (IS_ERR(iommu->group)) {
 937                 ret = PTR_ERR(iommu->group);
 938                 goto err_free_cache;
 939         }
 940
 941         iommu->base = devm_platform_ioremap_resource(pdev, 0);
 942         if (IS_ERR(iommu->base)) {
 943                 ret = PTR_ERR(iommu->base);
 944                 goto err_free_group;
 945         }
 946
 947         irq = platform_get_irq(pdev, 0);
 948         if (irq < 0) {
 949                 ret = irq;
 950                 goto err_free_group;
 951         }
 952
 953         iommu->clk = devm_clk_get(&pdev->dev, NULL);
 954         if (IS_ERR(iommu->clk)) {
 955                 dev_err(&pdev->dev, "Couldn't get our clock.\n");
 956                 ret = PTR_ERR(iommu->clk);
 957                 goto err_free_group;
 958         }
 959
 960         iommu->reset = devm_reset_control_get(&pdev->dev, NULL);
 961         if (IS_ERR(iommu->reset)) {
 962                 dev_err(&pdev->dev, "Couldn't get our reset line.\n");
 963                 ret = PTR_ERR(iommu->reset);
 964                 goto err_free_group;
 965         }
 966
 967         ret = iommu_device_sysfs_add(&iommu->iommu, &pdev->dev,
 968                                      NULL, dev_name(&pdev->dev));
 969         if (ret)
 970                 goto err_free_group;
 971
 972         iommu_device_set_ops(&iommu->iommu, &sun50i_iommu_ops);
 973         iommu_device_set_fwnode(&iommu->iommu, &pdev->dev.of_node->fwnode);
 974
 975         ret = iommu_device_register(&iommu->iommu);
 976         if (ret)
 977                 goto err_remove_sysfs;
 978
 979         ret = devm_request_irq(&pdev->dev, irq, sun50i_iommu_irq, 0,
 980                                dev_name(&pdev->dev), iommu);
 981         if (ret < 0)
 982                 goto err_unregister;
 983
 984         bus_set_iommu(&platform_bus_type, &sun50i_iommu_ops);
 985
 986         return 0;
 987
 988 err_unregister:
 989         iommu_device_unregister(&iommu->iommu);
 990
 991 err_remove_sysfs:
 992         iommu_device_sysfs_remove(&iommu->iommu);
 993
 994 err_free_group:
 995         iommu_group_put(iommu->group);
 996
 997 err_free_cache:
 998         kmem_cache_destroy(iommu->pt_pool);
 999
1000         return ret;
1001 }
1002
1003 static const struct of_device_id sun50i_iommu_dt[] = {
1004         { .compatible = "allwinner,sun50i-h6-iommu", },
1005         { /* sentinel */ },
1006 };
1007 MODULE_DEVICE_TABLE(of, sun50i_iommu_dt);
1008
1009 static struct platform_driver sun50i_iommu_driver = {
1010         .driver         = {
1011                 .name                   = "sun50i-iommu",
1012                 .of_match_table         = sun50i_iommu_dt,
1013                 .suppress_bind_attrs    = true,
1014         }
1015 };
1016 builtin_platform_driver_probe(sun50i_iommu_driver, sun50i_iommu_probe);
1017
1018 MODULE_DESCRIPTION("Allwinner H6 IOMMU driver");
1019 MODULE_AUTHOR("Maxime Ripard <maxime@cerno.tech>");
1020 MODULE_AUTHOR("zhuxianbin <zhuxianbin@allwinnertech.com>");
1021 MODULE_LICENSE("Dual BSD/GPL");