drivers/gpu/drm/panfrost/panfrost_mmu.c

   1 // SPDX-License-Identifier:     GPL-2.0
   2 /* Copyright 2019 Linaro, Ltd, Rob Herring <robh@kernel.org> */
   3 #include <linux/bitfield.h>
   4 #include <linux/delay.h>
   5 #include <linux/interrupt.h>
   6 #include <linux/io.h>
   7 #include <linux/iopoll.h>
   8 #include <linux/io-pgtable.h>
   9 #include <linux/iommu.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/pm_runtime.h>
  12 #include <linux/sizes.h>
  13
  14 #include "panfrost_device.h"
  15 #include "panfrost_mmu.h"
  16 #include "panfrost_gem.h"
  17 #include "panfrost_features.h"
  18 #include "panfrost_regs.h"
  19
  20 #define mmu_write(dev, reg, data) writel(data, dev->iomem + reg)
  21 #define mmu_read(dev, reg) readl(dev->iomem + reg)
  22
  23 struct panfrost_mmu {
  24         struct io_pgtable_cfg pgtbl_cfg;
  25         struct io_pgtable_ops *pgtbl_ops;
  26         struct mutex lock;
  27 };
  28
  29 static int wait_ready(struct panfrost_device *pfdev, u32 as_nr)
  30 {
  31         int ret;
  32         u32 val;
  33
  34         /* Wait for the MMU status to indicate there is no active command, in
  35          * case one is pending. */
  36         ret = readl_relaxed_poll_timeout_atomic(pfdev->iomem + AS_STATUS(as_nr),
  37                 val, !(val & AS_STATUS_AS_ACTIVE), 10, 1000);
  38
  39         if (ret)
  40                 dev_err(pfdev->dev, "AS_ACTIVE bit stuck\n");
  41
  42         return ret;
  43 }
  44
  45 static int write_cmd(struct panfrost_device *pfdev, u32 as_nr, u32 cmd)
  46 {
  47         int status;
  48
  49         /* write AS_COMMAND when MMU is ready to accept another command */
  50         status = wait_ready(pfdev, as_nr);
  51         if (!status)
  52                 mmu_write(pfdev, AS_COMMAND(as_nr), cmd);
  53
  54         return status;
  55 }
  56
  57 static void lock_region(struct panfrost_device *pfdev, u32 as_nr,
  58                         u64 iova, size_t size)
  59 {
  60         u8 region_width;
  61         u64 region = iova & PAGE_MASK;
  62         /*
  63          * fls returns:
  64          * 1 .. 32
  65          *
  66          * 10 + fls(num_pages)
  67          * results in the range (11 .. 42)
  68          */
  69
  70         size = round_up(size, PAGE_SIZE);
  71
  72         region_width = 10 + fls(size >> PAGE_SHIFT);
  73         if ((size >> PAGE_SHIFT) != (1ul << (region_width - 11))) {
  74                 /* not pow2, so must go up to the next pow2 */
  75                 region_width += 1;
  76         }
  77         region |= region_width;
  78
  79         /* Lock the region that needs to be updated */
  80         mmu_write(pfdev, AS_LOCKADDR_LO(as_nr), region & 0xFFFFFFFFUL);
  81         mmu_write(pfdev, AS_LOCKADDR_HI(as_nr), (region >> 32) & 0xFFFFFFFFUL);
  82         write_cmd(pfdev, as_nr, AS_COMMAND_LOCK);
  83 }
  84
  85
  86 static int mmu_hw_do_operation(struct panfrost_device *pfdev, u32 as_nr,
  87                 u64 iova, size_t size, u32 op)
  88 {
  89         unsigned long flags;
  90         int ret;
  91
  92         spin_lock_irqsave(&pfdev->hwaccess_lock, flags);
  93
  94         if (op != AS_COMMAND_UNLOCK)
  95                 lock_region(pfdev, as_nr, iova, size);
  96
  97         /* Run the MMU operation */
  98         write_cmd(pfdev, as_nr, op);
  99
 100         /* Wait for the flush to complete */
 101         ret = wait_ready(pfdev, as_nr);
 102
 103         spin_unlock_irqrestore(&pfdev->hwaccess_lock, flags);
 104
 105         return ret;
 106 }
 107
 108 void panfrost_mmu_enable(struct panfrost_device *pfdev, u32 as_nr)
 109 {
 110         struct io_pgtable_cfg *cfg = &pfdev->mmu->pgtbl_cfg;
 111         u64 transtab = cfg->arm_mali_lpae_cfg.transtab;
 112         u64 memattr = cfg->arm_mali_lpae_cfg.memattr;
 113
 114         mmu_write(pfdev, MMU_INT_CLEAR, ~0);
 115         mmu_write(pfdev, MMU_INT_MASK, ~0);
 116
 117         mmu_write(pfdev, AS_TRANSTAB_LO(as_nr), transtab & 0xffffffffUL);
 118         mmu_write(pfdev, AS_TRANSTAB_HI(as_nr), transtab >> 32);
 119
 120         /* Need to revisit mem attrs.
 121          * NC is the default, Mali driver is inner WT.
 122          */
 123         mmu_write(pfdev, AS_MEMATTR_LO(as_nr), memattr & 0xffffffffUL);
 124         mmu_write(pfdev, AS_MEMATTR_HI(as_nr), memattr >> 32);
 125
 126         write_cmd(pfdev, as_nr, AS_COMMAND_UPDATE);
 127 }
 128
 129 static void mmu_disable(struct panfrost_device *pfdev, u32 as_nr)
 130 {
 131         mmu_write(pfdev, AS_TRANSTAB_LO(as_nr), 0);
 132         mmu_write(pfdev, AS_TRANSTAB_HI(as_nr), 0);
 133
 134         mmu_write(pfdev, AS_MEMATTR_LO(as_nr), 0);
 135         mmu_write(pfdev, AS_MEMATTR_HI(as_nr), 0);
 136
 137         write_cmd(pfdev, as_nr, AS_COMMAND_UPDATE);
 138 }
 139
 140 static size_t get_pgsize(u64 addr, size_t size)
 141 {
 142         if (addr & (SZ_2M - 1) || size < SZ_2M)
 143                 return SZ_4K;
 144
 145         return SZ_2M;
 146 }
 147
 148 int panfrost_mmu_map(struct panfrost_gem_object *bo)
 149 {
 150         struct drm_gem_object *obj = &bo->base.base;
 151         struct panfrost_device *pfdev = to_panfrost_device(obj->dev);
 152         struct io_pgtable_ops *ops = pfdev->mmu->pgtbl_ops;
 153         u64 iova = bo->node.start << PAGE_SHIFT;
 154         unsigned int count;
 155         struct scatterlist *sgl;
 156         struct sg_table *sgt;
 157         int ret;
 158
 159         if (WARN_ON(bo->is_mapped))
 160                 return 0;
 161
 162         sgt = drm_gem_shmem_get_pages_sgt(obj);
 163         if (WARN_ON(IS_ERR(sgt)))
 164                 return PTR_ERR(sgt);
 165
 166         ret = pm_runtime_get_sync(pfdev->dev);
 167         if (ret < 0)
 168                 return ret;
 169
 170         mutex_lock(&pfdev->mmu->lock);
 171
 172         for_each_sg(sgt->sgl, sgl, sgt->nents, count) {
 173                 unsigned long paddr = sg_dma_address(sgl);
 174                 size_t len = sg_dma_len(sgl);
 175
 176                 dev_dbg(pfdev->dev, "map: iova=%llx, paddr=%lx, len=%zx", iova, paddr, len);
 177
 178                 while (len) {
 179                         size_t pgsize = get_pgsize(iova | paddr, len);
 180
 181                         ops->map(ops, iova, paddr, pgsize, IOMMU_WRITE | IOMMU_READ);
 182                         iova += pgsize;
 183                         paddr += pgsize;
 184                         len -= pgsize;
 185                 }
 186         }
 187
 188         mmu_hw_do_operation(pfdev, 0, bo->node.start << PAGE_SHIFT,
 189                             bo->node.size << PAGE_SHIFT, AS_COMMAND_FLUSH_PT);
 190
 191         mutex_unlock(&pfdev->mmu->lock);
 192
 193         pm_runtime_mark_last_busy(pfdev->dev);
 194         pm_runtime_put_autosuspend(pfdev->dev);
 195         bo->is_mapped = true;
 196
 197         return 0;
 198 }
 199
 200 void panfrost_mmu_unmap(struct panfrost_gem_object *bo)
 201 {
 202         struct drm_gem_object *obj = &bo->base.base;
 203         struct panfrost_device *pfdev = to_panfrost_device(obj->dev);
 204         struct io_pgtable_ops *ops = pfdev->mmu->pgtbl_ops;
 205         u64 iova = bo->node.start << PAGE_SHIFT;
 206         size_t len = bo->node.size << PAGE_SHIFT;
 207         size_t unmapped_len = 0;
 208         int ret;
 209
 210         if (WARN_ON(!bo->is_mapped))
 211                 return;
 212
 213         dev_dbg(pfdev->dev, "unmap: iova=%llx, len=%zx", iova, len);
 214
 215         ret = pm_runtime_get_sync(pfdev->dev);
 216         if (ret < 0)
 217                 return;
 218
 219         mutex_lock(&pfdev->mmu->lock);
 220
 221         while (unmapped_len < len) {
 222                 size_t unmapped_page;
 223                 size_t pgsize = get_pgsize(iova, len - unmapped_len);
 224
 225                 unmapped_page = ops->unmap(ops, iova, pgsize, NULL);
 226                 if (!unmapped_page)
 227                         break;
 228
 229                 iova += unmapped_page;
 230                 unmapped_len += unmapped_page;
 231         }
 232
 233         mmu_hw_do_operation(pfdev, 0, bo->node.start << PAGE_SHIFT,
 234                             bo->node.size << PAGE_SHIFT, AS_COMMAND_FLUSH_PT);
 235
 236         mutex_unlock(&pfdev->mmu->lock);
 237
 238         pm_runtime_mark_last_busy(pfdev->dev);
 239         pm_runtime_put_autosuspend(pfdev->dev);
 240         bo->is_mapped = false;
 241 }
 242
 243 static void mmu_tlb_inv_context_s1(void *cookie)
 244 {
 245         struct panfrost_device *pfdev = cookie;
 246
 247         mmu_hw_do_operation(pfdev, 0, 0, ~0UL, AS_COMMAND_FLUSH_MEM);
 248 }
 249
 250 static void mmu_tlb_sync_context(void *cookie)
 251 {
 252         //struct panfrost_device *pfdev = cookie;
 253         // TODO: Wait 1000 GPU cycles for HW_ISSUE_6367/T60X
 254 }
 255
 256 static void mmu_tlb_flush_walk(unsigned long iova, size_t size, size_t granule,
 257                                void *cookie)
 258 {
 259         mmu_tlb_sync_context(cookie);
 260 }
 261
 262 static void mmu_tlb_flush_leaf(unsigned long iova, size_t size, size_t granule,
 263                                void *cookie)
 264 {
 265         mmu_tlb_sync_context(cookie);
 266 }
 267
 268 static const struct iommu_flush_ops mmu_tlb_ops = {
 269         .tlb_flush_all  = mmu_tlb_inv_context_s1,
 270         .tlb_flush_walk = mmu_tlb_flush_walk,
 271         .tlb_flush_leaf = mmu_tlb_flush_leaf,
 272 };
 273
 274 static const char *access_type_name(struct panfrost_device *pfdev,
 275                 u32 fault_status)
 276 {
 277         switch (fault_status & AS_FAULTSTATUS_ACCESS_TYPE_MASK) {
 278         case AS_FAULTSTATUS_ACCESS_TYPE_ATOMIC:
 279                 if (panfrost_has_hw_feature(pfdev, HW_FEATURE_AARCH64_MMU))
 280                         return "ATOMIC";
 281                 else
 282                         return "UNKNOWN";
 283         case AS_FAULTSTATUS_ACCESS_TYPE_READ:
 284                 return "READ";
 285         case AS_FAULTSTATUS_ACCESS_TYPE_WRITE:
 286                 return "WRITE";
 287         case AS_FAULTSTATUS_ACCESS_TYPE_EX:
 288                 return "EXECUTE";
 289         default:
 290                 WARN_ON(1);
 291                 return NULL;
 292         }
 293 }
 294
 295 static irqreturn_t panfrost_mmu_irq_handler(int irq, void *data)
 296 {
 297         struct panfrost_device *pfdev = data;
 298         u32 status = mmu_read(pfdev, MMU_INT_STAT);
 299         int i;
 300
 301         if (!status)
 302                 return IRQ_NONE;
 303
 304         dev_err(pfdev->dev, "mmu irq status=%x\n", status);
 305
 306         for (i = 0; status; i++) {
 307                 u32 mask = BIT(i) | BIT(i + 16);
 308                 u64 addr;
 309                 u32 fault_status;
 310                 u32 exception_type;
 311                 u32 access_type;
 312                 u32 source_id;
 313
 314                 if (!(status & mask))
 315                         continue;
 316
 317                 fault_status = mmu_read(pfdev, AS_FAULTSTATUS(i));
 318                 addr = mmu_read(pfdev, AS_FAULTADDRESS_LO(i));
 319                 addr |= (u64)mmu_read(pfdev, AS_FAULTADDRESS_HI(i)) << 32;
 320
 321                 /* decode the fault status */
 322                 exception_type = fault_status & 0xFF;
 323                 access_type = (fault_status >> 8) & 0x3;
 324                 source_id = (fault_status >> 16);
 325
 326                 /* terminal fault, print info about the fault */
 327                 dev_err(pfdev->dev,
 328                         "Unhandled Page fault in AS%d at VA 0x%016llX\n"
 329                         "Reason: %s\n"
 330                         "raw fault status: 0x%X\n"
 331                         "decoded fault status: %s\n"
 332                         "exception type 0x%X: %s\n"
 333                         "access type 0x%X: %s\n"
 334                         "source id 0x%X\n",
 335                         i, addr,
 336                         "TODO",
 337                         fault_status,
 338                         (fault_status & (1 << 10) ? "DECODER FAULT" : "SLAVE FAULT"),
 339                         exception_type, panfrost_exception_name(pfdev, exception_type),
 340                         access_type, access_type_name(pfdev, fault_status),
 341                         source_id);
 342
 343                 mmu_write(pfdev, MMU_INT_CLEAR, mask);
 344
 345                 status &= ~mask;
 346         }
 347
 348         return IRQ_HANDLED;
 349 };
 350
 351 int panfrost_mmu_init(struct panfrost_device *pfdev)
 352 {
 353         struct io_pgtable_ops *pgtbl_ops;
 354         int err, irq;
 355
 356         pfdev->mmu = devm_kzalloc(pfdev->dev, sizeof(*pfdev->mmu), GFP_KERNEL);
 357         if (!pfdev->mmu)
 358                 return -ENOMEM;
 359
 360         mutex_init(&pfdev->mmu->lock);
 361
 362         irq = platform_get_irq_byname(to_platform_device(pfdev->dev), "mmu");
 363         if (irq <= 0)
 364                 return -ENODEV;
 365
 366         err = devm_request_irq(pfdev->dev, irq, panfrost_mmu_irq_handler,
 367                                IRQF_SHARED, "mmu", pfdev);
 368
 369         if (err) {
 370                 dev_err(pfdev->dev, "failed to request mmu irq");
 371                 return err;
 372         }
 373         mmu_write(pfdev, MMU_INT_CLEAR, ~0);
 374         mmu_write(pfdev, MMU_INT_MASK, ~0);
 375
 376         pfdev->mmu->pgtbl_cfg = (struct io_pgtable_cfg) {
 377                 .pgsize_bitmap  = SZ_4K | SZ_2M,
 378                 .ias            = FIELD_GET(0xff, pfdev->features.mmu_features),
 379                 .oas            = FIELD_GET(0xff00, pfdev->features.mmu_features),
 380                 .tlb            = &mmu_tlb_ops,
 381                 .iommu_dev      = pfdev->dev,
 382         };
 383
 384         pgtbl_ops = alloc_io_pgtable_ops(ARM_MALI_LPAE, &pfdev->mmu->pgtbl_cfg,
 385                                          pfdev);
 386         if (!pgtbl_ops)
 387                 return -ENOMEM;
 388
 389         pfdev->mmu->pgtbl_ops = pgtbl_ops;
 390
 391         panfrost_mmu_enable(pfdev, 0);
 392
 393         return 0;
 394 }
 395
 396 void panfrost_mmu_fini(struct panfrost_device *pfdev)
 397 {
 398         mmu_write(pfdev, MMU_INT_MASK, 0);
 399         mmu_disable(pfdev, 0);
 400
 401         free_io_pgtable_ops(pfdev->mmu->pgtbl_ops);
 402 }