1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * CPU-agnostic ARM page table allocator. 4 * 5 * ARMv7 Short-descriptor format, supporting 6 * - Basic memory attributes 7 * - Simplified access permissions (AP[2:1] model) 8 * - Backwards-compatible TEX remap 9 * - Large pages/supersections (if indicated by the caller) 10 * 11 * Not supporting: 12 * - Legacy access permissions (AP[2:0] model) 13 * 14 * Almost certainly never supporting: 15 * - PXN 16 * - Domains 17 * 18 * Copyright (C) 2014-2015 ARM Limited 19 * Copyright (c) 2014-2015 MediaTek Inc. 20 */ 21 22 #define pr_fmt(fmt) "arm-v7s io-pgtable: " fmt 23 24 #include <linux/atomic.h> 25 #include <linux/dma-mapping.h> 26 #include <linux/gfp.h> 27 #include <linux/io-pgtable.h> 28 #include <linux/iommu.h> 29 #include <linux/kernel.h> 30 #include <linux/kmemleak.h> 31 #include <linux/sizes.h> 32 #include <linux/slab.h> 33 #include <linux/spinlock.h> 34 #include <linux/types.h> 35 36 #include <asm/barrier.h> 37 38 /* Struct accessors */ 39 #define io_pgtable_to_data(x) \ 40 container_of((x), struct arm_v7s_io_pgtable, iop) 41 42 #define io_pgtable_ops_to_data(x) \ 43 io_pgtable_to_data(io_pgtable_ops_to_pgtable(x)) 44 45 /* 46 * We have 32 bits total; 12 bits resolved at level 1, 8 bits at level 2, 47 * and 12 bits in a page. With some carefully-chosen coefficients we can 48 * hide the ugly inconsistencies behind these macros and at least let the 49 * rest of the code pretend to be somewhat sane. 50 */ 51 #define ARM_V7S_ADDR_BITS 32 52 #define _ARM_V7S_LVL_BITS(lvl) (16 - (lvl) * 4) 53 #define ARM_V7S_LVL_SHIFT(lvl) (ARM_V7S_ADDR_BITS - (4 + 8 * (lvl))) 54 #define ARM_V7S_TABLE_SHIFT 10 55 56 #define ARM_V7S_PTES_PER_LVL(lvl) (1 << _ARM_V7S_LVL_BITS(lvl)) 57 #define ARM_V7S_TABLE_SIZE(lvl) \ 58 (ARM_V7S_PTES_PER_LVL(lvl) * sizeof(arm_v7s_iopte)) 59 60 #define ARM_V7S_BLOCK_SIZE(lvl) (1UL << ARM_V7S_LVL_SHIFT(lvl)) 61 #define ARM_V7S_LVL_MASK(lvl) ((u32)(~0U << ARM_V7S_LVL_SHIFT(lvl))) 62 #define ARM_V7S_TABLE_MASK ((u32)(~0U << ARM_V7S_TABLE_SHIFT)) 63 #define _ARM_V7S_IDX_MASK(lvl) (ARM_V7S_PTES_PER_LVL(lvl) - 1) 64 #define ARM_V7S_LVL_IDX(addr, lvl) ({ \ 65 int _l = lvl; \ 66 ((u32)(addr) >> ARM_V7S_LVL_SHIFT(_l)) & _ARM_V7S_IDX_MASK(_l); \ 67 }) 68 69 /* 70 * Large page/supersection entries are effectively a block of 16 page/section 71 * entries, along the lines of the LPAE contiguous hint, but all with the 72 * same output address. For want of a better common name we'll call them 73 * "contiguous" versions of their respective page/section entries here, but 74 * noting the distinction (WRT to TLB maintenance) that they represent *one* 75 * entry repeated 16 times, not 16 separate entries (as in the LPAE case). 76 */ 77 #define ARM_V7S_CONT_PAGES 16 78 79 /* PTE type bits: these are all mixed up with XN/PXN bits in most cases */ 80 #define ARM_V7S_PTE_TYPE_TABLE 0x1 81 #define ARM_V7S_PTE_TYPE_PAGE 0x2 82 #define ARM_V7S_PTE_TYPE_CONT_PAGE 0x1 83 84 #define ARM_V7S_PTE_IS_VALID(pte) (((pte) & 0x3) != 0) 85 #define ARM_V7S_PTE_IS_TABLE(pte, lvl) \ 86 ((lvl) == 1 && (((pte) & 0x3) == ARM_V7S_PTE_TYPE_TABLE)) 87 88 /* Page table bits */ 89 #define ARM_V7S_ATTR_XN(lvl) BIT(4 * (2 - (lvl))) 90 #define ARM_V7S_ATTR_B BIT(2) 91 #define ARM_V7S_ATTR_C BIT(3) 92 #define ARM_V7S_ATTR_NS_TABLE BIT(3) 93 #define ARM_V7S_ATTR_NS_SECTION BIT(19) 94 95 #define ARM_V7S_CONT_SECTION BIT(18) 96 #define ARM_V7S_CONT_PAGE_XN_SHIFT 15 97 98 /* 99 * The attribute bits are consistently ordered*, but occupy bits [17:10] of 100 * a level 1 PTE vs. bits [11:4] at level 2. Thus we define the individual 101 * fields relative to that 8-bit block, plus a total shift relative to the PTE. 102 */ 103 #define ARM_V7S_ATTR_SHIFT(lvl) (16 - (lvl) * 6) 104 105 #define ARM_V7S_ATTR_MASK 0xff 106 #define ARM_V7S_ATTR_AP0 BIT(0) 107 #define ARM_V7S_ATTR_AP1 BIT(1) 108 #define ARM_V7S_ATTR_AP2 BIT(5) 109 #define ARM_V7S_ATTR_S BIT(6) 110 #define ARM_V7S_ATTR_NG BIT(7) 111 #define ARM_V7S_TEX_SHIFT 2 112 #define ARM_V7S_TEX_MASK 0x7 113 #define ARM_V7S_ATTR_TEX(val) (((val) & ARM_V7S_TEX_MASK) << ARM_V7S_TEX_SHIFT) 114 115 /* MediaTek extend the two bits for PA 32bit/33bit */ 116 #define ARM_V7S_ATTR_MTK_PA_BIT32 BIT(9) 117 #define ARM_V7S_ATTR_MTK_PA_BIT33 BIT(4) 118 119 /* *well, except for TEX on level 2 large pages, of course :( */ 120 #define ARM_V7S_CONT_PAGE_TEX_SHIFT 6 121 #define ARM_V7S_CONT_PAGE_TEX_MASK (ARM_V7S_TEX_MASK << ARM_V7S_CONT_PAGE_TEX_SHIFT) 122 123 /* Simplified access permissions */ 124 #define ARM_V7S_PTE_AF ARM_V7S_ATTR_AP0 125 #define ARM_V7S_PTE_AP_UNPRIV ARM_V7S_ATTR_AP1 126 #define ARM_V7S_PTE_AP_RDONLY ARM_V7S_ATTR_AP2 127 128 /* Register bits */ 129 #define ARM_V7S_RGN_NC 0 130 #define ARM_V7S_RGN_WBWA 1 131 #define ARM_V7S_RGN_WT 2 132 #define ARM_V7S_RGN_WB 3 133 134 #define ARM_V7S_PRRR_TYPE_DEVICE 1 135 #define ARM_V7S_PRRR_TYPE_NORMAL 2 136 #define ARM_V7S_PRRR_TR(n, type) (((type) & 0x3) << ((n) * 2)) 137 #define ARM_V7S_PRRR_DS0 BIT(16) 138 #define ARM_V7S_PRRR_DS1 BIT(17) 139 #define ARM_V7S_PRRR_NS0 BIT(18) 140 #define ARM_V7S_PRRR_NS1 BIT(19) 141 #define ARM_V7S_PRRR_NOS(n) BIT((n) + 24) 142 143 #define ARM_V7S_NMRR_IR(n, attr) (((attr) & 0x3) << ((n) * 2)) 144 #define ARM_V7S_NMRR_OR(n, attr) (((attr) & 0x3) << ((n) * 2 + 16)) 145 146 #define ARM_V7S_TTBR_S BIT(1) 147 #define ARM_V7S_TTBR_NOS BIT(5) 148 #define ARM_V7S_TTBR_ORGN_ATTR(attr) (((attr) & 0x3) << 3) 149 #define ARM_V7S_TTBR_IRGN_ATTR(attr) \ 150 ((((attr) & 0x1) << 6) | (((attr) & 0x2) >> 1)) 151 152 #ifdef CONFIG_ZONE_DMA32 153 #define ARM_V7S_TABLE_GFP_DMA GFP_DMA32 154 #define ARM_V7S_TABLE_SLAB_FLAGS SLAB_CACHE_DMA32 155 #else 156 #define ARM_V7S_TABLE_GFP_DMA GFP_DMA 157 #define ARM_V7S_TABLE_SLAB_FLAGS SLAB_CACHE_DMA 158 #endif 159 160 typedef u32 arm_v7s_iopte; 161 162 static bool selftest_running; 163 164 struct arm_v7s_io_pgtable { 165 struct io_pgtable iop; 166 167 arm_v7s_iopte *pgd; 168 struct kmem_cache *l2_tables; 169 spinlock_t split_lock; 170 }; 171 172 static bool arm_v7s_pte_is_cont(arm_v7s_iopte pte, int lvl); 173 174 static dma_addr_t __arm_v7s_dma_addr(void *pages) 175 { 176 return (dma_addr_t)virt_to_phys(pages); 177 } 178 179 static bool arm_v7s_is_mtk_enabled(struct io_pgtable_cfg *cfg) 180 { 181 return IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT) && 182 (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT); 183 } 184 185 static arm_v7s_iopte paddr_to_iopte(phys_addr_t paddr, int lvl, 186 struct io_pgtable_cfg *cfg) 187 { 188 arm_v7s_iopte pte = paddr & ARM_V7S_LVL_MASK(lvl); 189 190 if (!arm_v7s_is_mtk_enabled(cfg)) 191 return pte; 192 193 if (paddr & BIT_ULL(32)) 194 pte |= ARM_V7S_ATTR_MTK_PA_BIT32; 195 if (paddr & BIT_ULL(33)) 196 pte |= ARM_V7S_ATTR_MTK_PA_BIT33; 197 return pte; 198 } 199 200 static phys_addr_t iopte_to_paddr(arm_v7s_iopte pte, int lvl, 201 struct io_pgtable_cfg *cfg) 202 { 203 arm_v7s_iopte mask; 204 phys_addr_t paddr; 205 206 if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) 207 mask = ARM_V7S_TABLE_MASK; 208 else if (arm_v7s_pte_is_cont(pte, lvl)) 209 mask = ARM_V7S_LVL_MASK(lvl) * ARM_V7S_CONT_PAGES; 210 else 211 mask = ARM_V7S_LVL_MASK(lvl); 212 213 paddr = pte & mask; 214 if (!arm_v7s_is_mtk_enabled(cfg)) 215 return paddr; 216 217 if (pte & ARM_V7S_ATTR_MTK_PA_BIT32) 218 paddr |= BIT_ULL(32); 219 if (pte & ARM_V7S_ATTR_MTK_PA_BIT33) 220 paddr |= BIT_ULL(33); 221 return paddr; 222 } 223 224 static arm_v7s_iopte *iopte_deref(arm_v7s_iopte pte, int lvl, 225 struct arm_v7s_io_pgtable *data) 226 { 227 return phys_to_virt(iopte_to_paddr(pte, lvl, &data->iop.cfg)); 228 } 229 230 static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, 231 struct arm_v7s_io_pgtable *data) 232 { 233 struct io_pgtable_cfg *cfg = &data->iop.cfg; 234 struct device *dev = cfg->iommu_dev; 235 phys_addr_t phys; 236 dma_addr_t dma; 237 size_t size = ARM_V7S_TABLE_SIZE(lvl); 238 void *table = NULL; 239 240 if (lvl == 1) 241 table = (void *)__get_free_pages( 242 __GFP_ZERO | ARM_V7S_TABLE_GFP_DMA, get_order(size)); 243 else if (lvl == 2) 244 table = kmem_cache_zalloc(data->l2_tables, gfp); 245 phys = virt_to_phys(table); 246 if (phys != (arm_v7s_iopte)phys) { 247 /* Doesn't fit in PTE */ 248 dev_err(dev, "Page table does not fit in PTE: %pa", &phys); 249 goto out_free; 250 } 251 if (table && !cfg->coherent_walk) { 252 dma = dma_map_single(dev, table, size, DMA_TO_DEVICE); 253 if (dma_mapping_error(dev, dma)) 254 goto out_free; 255 /* 256 * We depend on the IOMMU being able to work with any physical 257 * address directly, so if the DMA layer suggests otherwise by 258 * translating or truncating them, that bodes very badly... 259 */ 260 if (dma != phys) 261 goto out_unmap; 262 } 263 if (lvl == 2) 264 kmemleak_ignore(table); 265 return table; 266 267 out_unmap: 268 dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n"); 269 dma_unmap_single(dev, dma, size, DMA_TO_DEVICE); 270 out_free: 271 if (lvl == 1) 272 free_pages((unsigned long)table, get_order(size)); 273 else 274 kmem_cache_free(data->l2_tables, table); 275 return NULL; 276 } 277 278 static void __arm_v7s_free_table(void *table, int lvl, 279 struct arm_v7s_io_pgtable *data) 280 { 281 struct io_pgtable_cfg *cfg = &data->iop.cfg; 282 struct device *dev = cfg->iommu_dev; 283 size_t size = ARM_V7S_TABLE_SIZE(lvl); 284 285 if (!cfg->coherent_walk) 286 dma_unmap_single(dev, __arm_v7s_dma_addr(table), size, 287 DMA_TO_DEVICE); 288 if (lvl == 1) 289 free_pages((unsigned long)table, get_order(size)); 290 else 291 kmem_cache_free(data->l2_tables, table); 292 } 293 294 static void __arm_v7s_pte_sync(arm_v7s_iopte *ptep, int num_entries, 295 struct io_pgtable_cfg *cfg) 296 { 297 if (cfg->coherent_walk) 298 return; 299 300 dma_sync_single_for_device(cfg->iommu_dev, __arm_v7s_dma_addr(ptep), 301 num_entries * sizeof(*ptep), DMA_TO_DEVICE); 302 } 303 static void __arm_v7s_set_pte(arm_v7s_iopte *ptep, arm_v7s_iopte pte, 304 int num_entries, struct io_pgtable_cfg *cfg) 305 { 306 int i; 307 308 for (i = 0; i < num_entries; i++) 309 ptep[i] = pte; 310 311 __arm_v7s_pte_sync(ptep, num_entries, cfg); 312 } 313 314 static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl, 315 struct io_pgtable_cfg *cfg) 316 { 317 bool ap = !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS); 318 arm_v7s_iopte pte = ARM_V7S_ATTR_NG | ARM_V7S_ATTR_S; 319 320 if (!(prot & IOMMU_MMIO)) 321 pte |= ARM_V7S_ATTR_TEX(1); 322 if (ap) { 323 pte |= ARM_V7S_PTE_AF; 324 if (!(prot & IOMMU_PRIV)) 325 pte |= ARM_V7S_PTE_AP_UNPRIV; 326 if (!(prot & IOMMU_WRITE)) 327 pte |= ARM_V7S_PTE_AP_RDONLY; 328 } 329 pte <<= ARM_V7S_ATTR_SHIFT(lvl); 330 331 if ((prot & IOMMU_NOEXEC) && ap) 332 pte |= ARM_V7S_ATTR_XN(lvl); 333 if (prot & IOMMU_MMIO) 334 pte |= ARM_V7S_ATTR_B; 335 else if (prot & IOMMU_CACHE) 336 pte |= ARM_V7S_ATTR_B | ARM_V7S_ATTR_C; 337 338 pte |= ARM_V7S_PTE_TYPE_PAGE; 339 if (lvl == 1 && (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)) 340 pte |= ARM_V7S_ATTR_NS_SECTION; 341 342 return pte; 343 } 344 345 static int arm_v7s_pte_to_prot(arm_v7s_iopte pte, int lvl) 346 { 347 int prot = IOMMU_READ; 348 arm_v7s_iopte attr = pte >> ARM_V7S_ATTR_SHIFT(lvl); 349 350 if (!(attr & ARM_V7S_PTE_AP_RDONLY)) 351 prot |= IOMMU_WRITE; 352 if (!(attr & ARM_V7S_PTE_AP_UNPRIV)) 353 prot |= IOMMU_PRIV; 354 if ((attr & (ARM_V7S_TEX_MASK << ARM_V7S_TEX_SHIFT)) == 0) 355 prot |= IOMMU_MMIO; 356 else if (pte & ARM_V7S_ATTR_C) 357 prot |= IOMMU_CACHE; 358 if (pte & ARM_V7S_ATTR_XN(lvl)) 359 prot |= IOMMU_NOEXEC; 360 361 return prot; 362 } 363 364 static arm_v7s_iopte arm_v7s_pte_to_cont(arm_v7s_iopte pte, int lvl) 365 { 366 if (lvl == 1) { 367 pte |= ARM_V7S_CONT_SECTION; 368 } else if (lvl == 2) { 369 arm_v7s_iopte xn = pte & ARM_V7S_ATTR_XN(lvl); 370 arm_v7s_iopte tex = pte & ARM_V7S_CONT_PAGE_TEX_MASK; 371 372 pte ^= xn | tex | ARM_V7S_PTE_TYPE_PAGE; 373 pte |= (xn << ARM_V7S_CONT_PAGE_XN_SHIFT) | 374 (tex << ARM_V7S_CONT_PAGE_TEX_SHIFT) | 375 ARM_V7S_PTE_TYPE_CONT_PAGE; 376 } 377 return pte; 378 } 379 380 static arm_v7s_iopte arm_v7s_cont_to_pte(arm_v7s_iopte pte, int lvl) 381 { 382 if (lvl == 1) { 383 pte &= ~ARM_V7S_CONT_SECTION; 384 } else if (lvl == 2) { 385 arm_v7s_iopte xn = pte & BIT(ARM_V7S_CONT_PAGE_XN_SHIFT); 386 arm_v7s_iopte tex = pte & (ARM_V7S_CONT_PAGE_TEX_MASK << 387 ARM_V7S_CONT_PAGE_TEX_SHIFT); 388 389 pte ^= xn | tex | ARM_V7S_PTE_TYPE_CONT_PAGE; 390 pte |= (xn >> ARM_V7S_CONT_PAGE_XN_SHIFT) | 391 (tex >> ARM_V7S_CONT_PAGE_TEX_SHIFT) | 392 ARM_V7S_PTE_TYPE_PAGE; 393 } 394 return pte; 395 } 396 397 static bool arm_v7s_pte_is_cont(arm_v7s_iopte pte, int lvl) 398 { 399 if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte, lvl)) 400 return pte & ARM_V7S_CONT_SECTION; 401 else if (lvl == 2) 402 return !(pte & ARM_V7S_PTE_TYPE_PAGE); 403 return false; 404 } 405 406 static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *, 407 struct iommu_iotlb_gather *, unsigned long, 408 size_t, int, arm_v7s_iopte *); 409 410 static int arm_v7s_init_pte(struct arm_v7s_io_pgtable *data, 411 unsigned long iova, phys_addr_t paddr, int prot, 412 int lvl, int num_entries, arm_v7s_iopte *ptep) 413 { 414 struct io_pgtable_cfg *cfg = &data->iop.cfg; 415 arm_v7s_iopte pte; 416 int i; 417 418 for (i = 0; i < num_entries; i++) 419 if (ARM_V7S_PTE_IS_TABLE(ptep[i], lvl)) { 420 /* 421 * We need to unmap and free the old table before 422 * overwriting it with a block entry. 423 */ 424 arm_v7s_iopte *tblp; 425 size_t sz = ARM_V7S_BLOCK_SIZE(lvl); 426 427 tblp = ptep - ARM_V7S_LVL_IDX(iova, lvl); 428 if (WARN_ON(__arm_v7s_unmap(data, NULL, iova + i * sz, 429 sz, lvl, tblp) != sz)) 430 return -EINVAL; 431 } else if (ptep[i]) { 432 /* We require an unmap first */ 433 WARN_ON(!selftest_running); 434 return -EEXIST; 435 } 436 437 pte = arm_v7s_prot_to_pte(prot, lvl, cfg); 438 if (num_entries > 1) 439 pte = arm_v7s_pte_to_cont(pte, lvl); 440 441 pte |= paddr_to_iopte(paddr, lvl, cfg); 442 443 __arm_v7s_set_pte(ptep, pte, num_entries, cfg); 444 return 0; 445 } 446 447 static arm_v7s_iopte arm_v7s_install_table(arm_v7s_iopte *table, 448 arm_v7s_iopte *ptep, 449 arm_v7s_iopte curr, 450 struct io_pgtable_cfg *cfg) 451 { 452 arm_v7s_iopte old, new; 453 454 new = virt_to_phys(table) | ARM_V7S_PTE_TYPE_TABLE; 455 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS) 456 new |= ARM_V7S_ATTR_NS_TABLE; 457 458 /* 459 * Ensure the table itself is visible before its PTE can be. 460 * Whilst we could get away with cmpxchg64_release below, this 461 * doesn't have any ordering semantics when !CONFIG_SMP. 462 */ 463 dma_wmb(); 464 465 old = cmpxchg_relaxed(ptep, curr, new); 466 __arm_v7s_pte_sync(ptep, 1, cfg); 467 468 return old; 469 } 470 471 static int __arm_v7s_map(struct arm_v7s_io_pgtable *data, unsigned long iova, 472 phys_addr_t paddr, size_t size, int prot, 473 int lvl, arm_v7s_iopte *ptep, gfp_t gfp) 474 { 475 struct io_pgtable_cfg *cfg = &data->iop.cfg; 476 arm_v7s_iopte pte, *cptep; 477 int num_entries = size >> ARM_V7S_LVL_SHIFT(lvl); 478 479 /* Find our entry at the current level */ 480 ptep += ARM_V7S_LVL_IDX(iova, lvl); 481 482 /* If we can install a leaf entry at this level, then do so */ 483 if (num_entries) 484 return arm_v7s_init_pte(data, iova, paddr, prot, 485 lvl, num_entries, ptep); 486 487 /* We can't allocate tables at the final level */ 488 if (WARN_ON(lvl == 2)) 489 return -EINVAL; 490 491 /* Grab a pointer to the next level */ 492 pte = READ_ONCE(*ptep); 493 if (!pte) { 494 cptep = __arm_v7s_alloc_table(lvl + 1, gfp, data); 495 if (!cptep) 496 return -ENOMEM; 497 498 pte = arm_v7s_install_table(cptep, ptep, 0, cfg); 499 if (pte) 500 __arm_v7s_free_table(cptep, lvl + 1, data); 501 } else { 502 /* We've no easy way of knowing if it's synced yet, so... */ 503 __arm_v7s_pte_sync(ptep, 1, cfg); 504 } 505 506 if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) { 507 cptep = iopte_deref(pte, lvl, data); 508 } else if (pte) { 509 /* We require an unmap first */ 510 WARN_ON(!selftest_running); 511 return -EEXIST; 512 } 513 514 /* Rinse, repeat */ 515 return __arm_v7s_map(data, iova, paddr, size, prot, lvl + 1, cptep, gfp); 516 } 517 518 static int arm_v7s_map(struct io_pgtable_ops *ops, unsigned long iova, 519 phys_addr_t paddr, size_t size, int prot, gfp_t gfp) 520 { 521 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); 522 struct io_pgtable *iop = &data->iop; 523 int ret; 524 525 /* If no access, then nothing to do */ 526 if (!(prot & (IOMMU_READ | IOMMU_WRITE))) 527 return 0; 528 529 if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias) || 530 paddr >= (1ULL << data->iop.cfg.oas))) 531 return -ERANGE; 532 533 ret = __arm_v7s_map(data, iova, paddr, size, prot, 1, data->pgd, gfp); 534 /* 535 * Synchronise all PTE updates for the new mapping before there's 536 * a chance for anything to kick off a table walk for the new iova. 537 */ 538 if (iop->cfg.quirks & IO_PGTABLE_QUIRK_TLBI_ON_MAP) { 539 io_pgtable_tlb_flush_walk(iop, iova, size, 540 ARM_V7S_BLOCK_SIZE(2)); 541 } else { 542 wmb(); 543 } 544 545 return ret; 546 } 547 548 static void arm_v7s_free_pgtable(struct io_pgtable *iop) 549 { 550 struct arm_v7s_io_pgtable *data = io_pgtable_to_data(iop); 551 int i; 552 553 for (i = 0; i < ARM_V7S_PTES_PER_LVL(1); i++) { 554 arm_v7s_iopte pte = data->pgd[i]; 555 556 if (ARM_V7S_PTE_IS_TABLE(pte, 1)) 557 __arm_v7s_free_table(iopte_deref(pte, 1, data), 558 2, data); 559 } 560 __arm_v7s_free_table(data->pgd, 1, data); 561 kmem_cache_destroy(data->l2_tables); 562 kfree(data); 563 } 564 565 static arm_v7s_iopte arm_v7s_split_cont(struct arm_v7s_io_pgtable *data, 566 unsigned long iova, int idx, int lvl, 567 arm_v7s_iopte *ptep) 568 { 569 struct io_pgtable *iop = &data->iop; 570 arm_v7s_iopte pte; 571 size_t size = ARM_V7S_BLOCK_SIZE(lvl); 572 int i; 573 574 /* Check that we didn't lose a race to get the lock */ 575 pte = *ptep; 576 if (!arm_v7s_pte_is_cont(pte, lvl)) 577 return pte; 578 579 ptep -= idx & (ARM_V7S_CONT_PAGES - 1); 580 pte = arm_v7s_cont_to_pte(pte, lvl); 581 for (i = 0; i < ARM_V7S_CONT_PAGES; i++) 582 ptep[i] = pte + i * size; 583 584 __arm_v7s_pte_sync(ptep, ARM_V7S_CONT_PAGES, &iop->cfg); 585 586 size *= ARM_V7S_CONT_PAGES; 587 io_pgtable_tlb_flush_leaf(iop, iova, size, size); 588 return pte; 589 } 590 591 static size_t arm_v7s_split_blk_unmap(struct arm_v7s_io_pgtable *data, 592 struct iommu_iotlb_gather *gather, 593 unsigned long iova, size_t size, 594 arm_v7s_iopte blk_pte, 595 arm_v7s_iopte *ptep) 596 { 597 struct io_pgtable_cfg *cfg = &data->iop.cfg; 598 arm_v7s_iopte pte, *tablep; 599 int i, unmap_idx, num_entries, num_ptes; 600 601 tablep = __arm_v7s_alloc_table(2, GFP_ATOMIC, data); 602 if (!tablep) 603 return 0; /* Bytes unmapped */ 604 605 num_ptes = ARM_V7S_PTES_PER_LVL(2); 606 num_entries = size >> ARM_V7S_LVL_SHIFT(2); 607 unmap_idx = ARM_V7S_LVL_IDX(iova, 2); 608 609 pte = arm_v7s_prot_to_pte(arm_v7s_pte_to_prot(blk_pte, 1), 2, cfg); 610 if (num_entries > 1) 611 pte = arm_v7s_pte_to_cont(pte, 2); 612 613 for (i = 0; i < num_ptes; i += num_entries, pte += size) { 614 /* Unmap! */ 615 if (i == unmap_idx) 616 continue; 617 618 __arm_v7s_set_pte(&tablep[i], pte, num_entries, cfg); 619 } 620 621 pte = arm_v7s_install_table(tablep, ptep, blk_pte, cfg); 622 if (pte != blk_pte) { 623 __arm_v7s_free_table(tablep, 2, data); 624 625 if (!ARM_V7S_PTE_IS_TABLE(pte, 1)) 626 return 0; 627 628 tablep = iopte_deref(pte, 1, data); 629 return __arm_v7s_unmap(data, gather, iova, size, 2, tablep); 630 } 631 632 io_pgtable_tlb_add_page(&data->iop, gather, iova, size); 633 return size; 634 } 635 636 static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *data, 637 struct iommu_iotlb_gather *gather, 638 unsigned long iova, size_t size, int lvl, 639 arm_v7s_iopte *ptep) 640 { 641 arm_v7s_iopte pte[ARM_V7S_CONT_PAGES]; 642 struct io_pgtable *iop = &data->iop; 643 int idx, i = 0, num_entries = size >> ARM_V7S_LVL_SHIFT(lvl); 644 645 /* Something went horribly wrong and we ran out of page table */ 646 if (WARN_ON(lvl > 2)) 647 return 0; 648 649 idx = ARM_V7S_LVL_IDX(iova, lvl); 650 ptep += idx; 651 do { 652 pte[i] = READ_ONCE(ptep[i]); 653 if (WARN_ON(!ARM_V7S_PTE_IS_VALID(pte[i]))) 654 return 0; 655 } while (++i < num_entries); 656 657 /* 658 * If we've hit a contiguous 'large page' entry at this level, it 659 * needs splitting first, unless we're unmapping the whole lot. 660 * 661 * For splitting, we can't rewrite 16 PTEs atomically, and since we 662 * can't necessarily assume TEX remap we don't have a software bit to 663 * mark live entries being split. In practice (i.e. DMA API code), we 664 * will never be splitting large pages anyway, so just wrap this edge 665 * case in a lock for the sake of correctness and be done with it. 666 */ 667 if (num_entries <= 1 && arm_v7s_pte_is_cont(pte[0], lvl)) { 668 unsigned long flags; 669 670 spin_lock_irqsave(&data->split_lock, flags); 671 pte[0] = arm_v7s_split_cont(data, iova, idx, lvl, ptep); 672 spin_unlock_irqrestore(&data->split_lock, flags); 673 } 674 675 /* If the size matches this level, we're in the right place */ 676 if (num_entries) { 677 size_t blk_size = ARM_V7S_BLOCK_SIZE(lvl); 678 679 __arm_v7s_set_pte(ptep, 0, num_entries, &iop->cfg); 680 681 for (i = 0; i < num_entries; i++) { 682 if (ARM_V7S_PTE_IS_TABLE(pte[i], lvl)) { 683 /* Also flush any partial walks */ 684 io_pgtable_tlb_flush_walk(iop, iova, blk_size, 685 ARM_V7S_BLOCK_SIZE(lvl + 1)); 686 ptep = iopte_deref(pte[i], lvl, data); 687 __arm_v7s_free_table(ptep, lvl + 1, data); 688 } else if (iop->cfg.quirks & IO_PGTABLE_QUIRK_NON_STRICT) { 689 /* 690 * Order the PTE update against queueing the IOVA, to 691 * guarantee that a flush callback from a different CPU 692 * has observed it before the TLBIALL can be issued. 693 */ 694 smp_wmb(); 695 } else { 696 io_pgtable_tlb_add_page(iop, gather, iova, blk_size); 697 } 698 iova += blk_size; 699 } 700 return size; 701 } else if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte[0], lvl)) { 702 /* 703 * Insert a table at the next level to map the old region, 704 * minus the part we want to unmap 705 */ 706 return arm_v7s_split_blk_unmap(data, gather, iova, size, pte[0], 707 ptep); 708 } 709 710 /* Keep on walkin' */ 711 ptep = iopte_deref(pte[0], lvl, data); 712 return __arm_v7s_unmap(data, gather, iova, size, lvl + 1, ptep); 713 } 714 715 static size_t arm_v7s_unmap(struct io_pgtable_ops *ops, unsigned long iova, 716 size_t size, struct iommu_iotlb_gather *gather) 717 { 718 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); 719 720 if (WARN_ON(upper_32_bits(iova))) 721 return 0; 722 723 return __arm_v7s_unmap(data, gather, iova, size, 1, data->pgd); 724 } 725 726 static phys_addr_t arm_v7s_iova_to_phys(struct io_pgtable_ops *ops, 727 unsigned long iova) 728 { 729 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); 730 arm_v7s_iopte *ptep = data->pgd, pte; 731 int lvl = 0; 732 u32 mask; 733 734 do { 735 ptep += ARM_V7S_LVL_IDX(iova, ++lvl); 736 pte = READ_ONCE(*ptep); 737 ptep = iopte_deref(pte, lvl, data); 738 } while (ARM_V7S_PTE_IS_TABLE(pte, lvl)); 739 740 if (!ARM_V7S_PTE_IS_VALID(pte)) 741 return 0; 742 743 mask = ARM_V7S_LVL_MASK(lvl); 744 if (arm_v7s_pte_is_cont(pte, lvl)) 745 mask *= ARM_V7S_CONT_PAGES; 746 return iopte_to_paddr(pte, lvl, &data->iop.cfg) | (iova & ~mask); 747 } 748 749 static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, 750 void *cookie) 751 { 752 struct arm_v7s_io_pgtable *data; 753 754 if (cfg->ias > ARM_V7S_ADDR_BITS) 755 return NULL; 756 757 if (cfg->oas > (arm_v7s_is_mtk_enabled(cfg) ? 34 : ARM_V7S_ADDR_BITS)) 758 return NULL; 759 760 if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | 761 IO_PGTABLE_QUIRK_NO_PERMS | 762 IO_PGTABLE_QUIRK_TLBI_ON_MAP | 763 IO_PGTABLE_QUIRK_ARM_MTK_EXT | 764 IO_PGTABLE_QUIRK_NON_STRICT)) 765 return NULL; 766 767 /* If ARM_MTK_4GB is enabled, the NO_PERMS is also expected. */ 768 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT && 769 !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS)) 770 return NULL; 771 772 data = kmalloc(sizeof(*data), GFP_KERNEL); 773 if (!data) 774 return NULL; 775 776 spin_lock_init(&data->split_lock); 777 data->l2_tables = kmem_cache_create("io-pgtable_armv7s_l2", 778 ARM_V7S_TABLE_SIZE(2), 779 ARM_V7S_TABLE_SIZE(2), 780 ARM_V7S_TABLE_SLAB_FLAGS, NULL); 781 if (!data->l2_tables) 782 goto out_free_data; 783 784 data->iop.ops = (struct io_pgtable_ops) { 785 .map = arm_v7s_map, 786 .unmap = arm_v7s_unmap, 787 .iova_to_phys = arm_v7s_iova_to_phys, 788 }; 789 790 /* We have to do this early for __arm_v7s_alloc_table to work... */ 791 data->iop.cfg = *cfg; 792 793 /* 794 * Unless the IOMMU driver indicates supersection support by 795 * having SZ_16M set in the initial bitmap, they won't be used. 796 */ 797 cfg->pgsize_bitmap &= SZ_4K | SZ_64K | SZ_1M | SZ_16M; 798 799 /* TCR: T0SZ=0, EAE=0 (if applicable) */ 800 cfg->arm_v7s_cfg.tcr = 0; 801 802 /* 803 * TEX remap: the indices used map to the closest equivalent types 804 * under the non-TEX-remap interpretation of those attribute bits, 805 * excepting various implementation-defined aspects of shareability. 806 */ 807 cfg->arm_v7s_cfg.prrr = ARM_V7S_PRRR_TR(1, ARM_V7S_PRRR_TYPE_DEVICE) | 808 ARM_V7S_PRRR_TR(4, ARM_V7S_PRRR_TYPE_NORMAL) | 809 ARM_V7S_PRRR_TR(7, ARM_V7S_PRRR_TYPE_NORMAL) | 810 ARM_V7S_PRRR_DS0 | ARM_V7S_PRRR_DS1 | 811 ARM_V7S_PRRR_NS1 | ARM_V7S_PRRR_NOS(7); 812 cfg->arm_v7s_cfg.nmrr = ARM_V7S_NMRR_IR(7, ARM_V7S_RGN_WBWA) | 813 ARM_V7S_NMRR_OR(7, ARM_V7S_RGN_WBWA); 814 815 /* Looking good; allocate a pgd */ 816 data->pgd = __arm_v7s_alloc_table(1, GFP_KERNEL, data); 817 if (!data->pgd) 818 goto out_free_data; 819 820 /* Ensure the empty pgd is visible before any actual TTBR write */ 821 wmb(); 822 823 /* TTBR */ 824 cfg->arm_v7s_cfg.ttbr = virt_to_phys(data->pgd) | ARM_V7S_TTBR_S | 825 (cfg->coherent_walk ? (ARM_V7S_TTBR_NOS | 826 ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) | 827 ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) : 828 (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) | 829 ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC))); 830 return &data->iop; 831 832 out_free_data: 833 kmem_cache_destroy(data->l2_tables); 834 kfree(data); 835 return NULL; 836 } 837 838 struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = { 839 .alloc = arm_v7s_alloc_pgtable, 840 .free = arm_v7s_free_pgtable, 841 }; 842 843 #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST 844 845 static struct io_pgtable_cfg *cfg_cookie __initdata; 846 847 static void __init dummy_tlb_flush_all(void *cookie) 848 { 849 WARN_ON(cookie != cfg_cookie); 850 } 851 852 static void __init dummy_tlb_flush(unsigned long iova, size_t size, 853 size_t granule, void *cookie) 854 { 855 WARN_ON(cookie != cfg_cookie); 856 WARN_ON(!(size & cfg_cookie->pgsize_bitmap)); 857 } 858 859 static void __init dummy_tlb_add_page(struct iommu_iotlb_gather *gather, 860 unsigned long iova, size_t granule, 861 void *cookie) 862 { 863 dummy_tlb_flush(iova, granule, granule, cookie); 864 } 865 866 static const struct iommu_flush_ops dummy_tlb_ops __initconst = { 867 .tlb_flush_all = dummy_tlb_flush_all, 868 .tlb_flush_walk = dummy_tlb_flush, 869 .tlb_flush_leaf = dummy_tlb_flush, 870 .tlb_add_page = dummy_tlb_add_page, 871 }; 872 873 #define __FAIL(ops) ({ \ 874 WARN(1, "selftest: test failed\n"); \ 875 selftest_running = false; \ 876 -EFAULT; \ 877 }) 878 879 static int __init arm_v7s_do_selftests(void) 880 { 881 struct io_pgtable_ops *ops; 882 struct io_pgtable_cfg cfg = { 883 .tlb = &dummy_tlb_ops, 884 .oas = 32, 885 .ias = 32, 886 .coherent_walk = true, 887 .quirks = IO_PGTABLE_QUIRK_ARM_NS, 888 .pgsize_bitmap = SZ_4K | SZ_64K | SZ_1M | SZ_16M, 889 }; 890 unsigned int iova, size, iova_start; 891 unsigned int i, loopnr = 0; 892 893 selftest_running = true; 894 895 cfg_cookie = &cfg; 896 897 ops = alloc_io_pgtable_ops(ARM_V7S, &cfg, &cfg); 898 if (!ops) { 899 pr_err("selftest: failed to allocate io pgtable ops\n"); 900 return -EINVAL; 901 } 902 903 /* 904 * Initial sanity checks. 905 * Empty page tables shouldn't provide any translations. 906 */ 907 if (ops->iova_to_phys(ops, 42)) 908 return __FAIL(ops); 909 910 if (ops->iova_to_phys(ops, SZ_1G + 42)) 911 return __FAIL(ops); 912 913 if (ops->iova_to_phys(ops, SZ_2G + 42)) 914 return __FAIL(ops); 915 916 /* 917 * Distinct mappings of different granule sizes. 918 */ 919 iova = 0; 920 for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) { 921 size = 1UL << i; 922 if (ops->map(ops, iova, iova, size, IOMMU_READ | 923 IOMMU_WRITE | 924 IOMMU_NOEXEC | 925 IOMMU_CACHE, GFP_KERNEL)) 926 return __FAIL(ops); 927 928 /* Overlapping mappings */ 929 if (!ops->map(ops, iova, iova + size, size, 930 IOMMU_READ | IOMMU_NOEXEC, GFP_KERNEL)) 931 return __FAIL(ops); 932 933 if (ops->iova_to_phys(ops, iova + 42) != (iova + 42)) 934 return __FAIL(ops); 935 936 iova += SZ_16M; 937 loopnr++; 938 } 939 940 /* Partial unmap */ 941 i = 1; 942 size = 1UL << __ffs(cfg.pgsize_bitmap); 943 while (i < loopnr) { 944 iova_start = i * SZ_16M; 945 if (ops->unmap(ops, iova_start + size, size, NULL) != size) 946 return __FAIL(ops); 947 948 /* Remap of partial unmap */ 949 if (ops->map(ops, iova_start + size, size, size, IOMMU_READ, GFP_KERNEL)) 950 return __FAIL(ops); 951 952 if (ops->iova_to_phys(ops, iova_start + size + 42) 953 != (size + 42)) 954 return __FAIL(ops); 955 i++; 956 } 957 958 /* Full unmap */ 959 iova = 0; 960 for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) { 961 size = 1UL << i; 962 963 if (ops->unmap(ops, iova, size, NULL) != size) 964 return __FAIL(ops); 965 966 if (ops->iova_to_phys(ops, iova + 42)) 967 return __FAIL(ops); 968 969 /* Remap full block */ 970 if (ops->map(ops, iova, iova, size, IOMMU_WRITE, GFP_KERNEL)) 971 return __FAIL(ops); 972 973 if (ops->iova_to_phys(ops, iova + 42) != (iova + 42)) 974 return __FAIL(ops); 975 976 iova += SZ_16M; 977 } 978 979 free_io_pgtable_ops(ops); 980 981 selftest_running = false; 982 983 pr_info("self test ok\n"); 984 return 0; 985 } 986 subsys_initcall(arm_v7s_do_selftests); 987 #endif 988