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 #define ARM_V7S_TCR_PD1 BIT(5) 153 154 #ifdef CONFIG_ZONE_DMA32 155 #define ARM_V7S_TABLE_GFP_DMA GFP_DMA32 156 #define ARM_V7S_TABLE_SLAB_FLAGS SLAB_CACHE_DMA32 157 #else 158 #define ARM_V7S_TABLE_GFP_DMA GFP_DMA 159 #define ARM_V7S_TABLE_SLAB_FLAGS SLAB_CACHE_DMA 160 #endif 161 162 typedef u32 arm_v7s_iopte; 163 164 static bool selftest_running; 165 166 struct arm_v7s_io_pgtable { 167 struct io_pgtable iop; 168 169 arm_v7s_iopte *pgd; 170 struct kmem_cache *l2_tables; 171 spinlock_t split_lock; 172 }; 173 174 static bool arm_v7s_pte_is_cont(arm_v7s_iopte pte, int lvl); 175 176 static dma_addr_t __arm_v7s_dma_addr(void *pages) 177 { 178 return (dma_addr_t)virt_to_phys(pages); 179 } 180 181 static bool arm_v7s_is_mtk_enabled(struct io_pgtable_cfg *cfg) 182 { 183 return IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT) && 184 (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT); 185 } 186 187 static arm_v7s_iopte paddr_to_iopte(phys_addr_t paddr, int lvl, 188 struct io_pgtable_cfg *cfg) 189 { 190 arm_v7s_iopte pte = paddr & ARM_V7S_LVL_MASK(lvl); 191 192 if (!arm_v7s_is_mtk_enabled(cfg)) 193 return pte; 194 195 if (paddr & BIT_ULL(32)) 196 pte |= ARM_V7S_ATTR_MTK_PA_BIT32; 197 if (paddr & BIT_ULL(33)) 198 pte |= ARM_V7S_ATTR_MTK_PA_BIT33; 199 return pte; 200 } 201 202 static phys_addr_t iopte_to_paddr(arm_v7s_iopte pte, int lvl, 203 struct io_pgtable_cfg *cfg) 204 { 205 arm_v7s_iopte mask; 206 phys_addr_t paddr; 207 208 if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) 209 mask = ARM_V7S_TABLE_MASK; 210 else if (arm_v7s_pte_is_cont(pte, lvl)) 211 mask = ARM_V7S_LVL_MASK(lvl) * ARM_V7S_CONT_PAGES; 212 else 213 mask = ARM_V7S_LVL_MASK(lvl); 214 215 paddr = pte & mask; 216 if (!arm_v7s_is_mtk_enabled(cfg)) 217 return paddr; 218 219 if (pte & ARM_V7S_ATTR_MTK_PA_BIT32) 220 paddr |= BIT_ULL(32); 221 if (pte & ARM_V7S_ATTR_MTK_PA_BIT33) 222 paddr |= BIT_ULL(33); 223 return paddr; 224 } 225 226 static arm_v7s_iopte *iopte_deref(arm_v7s_iopte pte, int lvl, 227 struct arm_v7s_io_pgtable *data) 228 { 229 return phys_to_virt(iopte_to_paddr(pte, lvl, &data->iop.cfg)); 230 } 231 232 static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, 233 struct arm_v7s_io_pgtable *data) 234 { 235 struct io_pgtable_cfg *cfg = &data->iop.cfg; 236 struct device *dev = cfg->iommu_dev; 237 phys_addr_t phys; 238 dma_addr_t dma; 239 size_t size = ARM_V7S_TABLE_SIZE(lvl); 240 void *table = NULL; 241 242 if (lvl == 1) 243 table = (void *)__get_free_pages( 244 __GFP_ZERO | ARM_V7S_TABLE_GFP_DMA, get_order(size)); 245 else if (lvl == 2) 246 table = kmem_cache_zalloc(data->l2_tables, gfp); 247 phys = virt_to_phys(table); 248 if (phys != (arm_v7s_iopte)phys) { 249 /* Doesn't fit in PTE */ 250 dev_err(dev, "Page table does not fit in PTE: %pa", &phys); 251 goto out_free; 252 } 253 if (table && !cfg->coherent_walk) { 254 dma = dma_map_single(dev, table, size, DMA_TO_DEVICE); 255 if (dma_mapping_error(dev, dma)) 256 goto out_free; 257 /* 258 * We depend on the IOMMU being able to work with any physical 259 * address directly, so if the DMA layer suggests otherwise by 260 * translating or truncating them, that bodes very badly... 261 */ 262 if (dma != phys) 263 goto out_unmap; 264 } 265 if (lvl == 2) 266 kmemleak_ignore(table); 267 return table; 268 269 out_unmap: 270 dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n"); 271 dma_unmap_single(dev, dma, size, DMA_TO_DEVICE); 272 out_free: 273 if (lvl == 1) 274 free_pages((unsigned long)table, get_order(size)); 275 else 276 kmem_cache_free(data->l2_tables, table); 277 return NULL; 278 } 279 280 static void __arm_v7s_free_table(void *table, int lvl, 281 struct arm_v7s_io_pgtable *data) 282 { 283 struct io_pgtable_cfg *cfg = &data->iop.cfg; 284 struct device *dev = cfg->iommu_dev; 285 size_t size = ARM_V7S_TABLE_SIZE(lvl); 286 287 if (!cfg->coherent_walk) 288 dma_unmap_single(dev, __arm_v7s_dma_addr(table), size, 289 DMA_TO_DEVICE); 290 if (lvl == 1) 291 free_pages((unsigned long)table, get_order(size)); 292 else 293 kmem_cache_free(data->l2_tables, table); 294 } 295 296 static void __arm_v7s_pte_sync(arm_v7s_iopte *ptep, int num_entries, 297 struct io_pgtable_cfg *cfg) 298 { 299 if (cfg->coherent_walk) 300 return; 301 302 dma_sync_single_for_device(cfg->iommu_dev, __arm_v7s_dma_addr(ptep), 303 num_entries * sizeof(*ptep), DMA_TO_DEVICE); 304 } 305 static void __arm_v7s_set_pte(arm_v7s_iopte *ptep, arm_v7s_iopte pte, 306 int num_entries, struct io_pgtable_cfg *cfg) 307 { 308 int i; 309 310 for (i = 0; i < num_entries; i++) 311 ptep[i] = pte; 312 313 __arm_v7s_pte_sync(ptep, num_entries, cfg); 314 } 315 316 static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl, 317 struct io_pgtable_cfg *cfg) 318 { 319 bool ap = !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS); 320 arm_v7s_iopte pte = ARM_V7S_ATTR_NG | ARM_V7S_ATTR_S; 321 322 if (!(prot & IOMMU_MMIO)) 323 pte |= ARM_V7S_ATTR_TEX(1); 324 if (ap) { 325 pte |= ARM_V7S_PTE_AF; 326 if (!(prot & IOMMU_PRIV)) 327 pte |= ARM_V7S_PTE_AP_UNPRIV; 328 if (!(prot & IOMMU_WRITE)) 329 pte |= ARM_V7S_PTE_AP_RDONLY; 330 } 331 pte <<= ARM_V7S_ATTR_SHIFT(lvl); 332 333 if ((prot & IOMMU_NOEXEC) && ap) 334 pte |= ARM_V7S_ATTR_XN(lvl); 335 if (prot & IOMMU_MMIO) 336 pte |= ARM_V7S_ATTR_B; 337 else if (prot & IOMMU_CACHE) 338 pte |= ARM_V7S_ATTR_B | ARM_V7S_ATTR_C; 339 340 pte |= ARM_V7S_PTE_TYPE_PAGE; 341 if (lvl == 1 && (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)) 342 pte |= ARM_V7S_ATTR_NS_SECTION; 343 344 return pte; 345 } 346 347 static int arm_v7s_pte_to_prot(arm_v7s_iopte pte, int lvl) 348 { 349 int prot = IOMMU_READ; 350 arm_v7s_iopte attr = pte >> ARM_V7S_ATTR_SHIFT(lvl); 351 352 if (!(attr & ARM_V7S_PTE_AP_RDONLY)) 353 prot |= IOMMU_WRITE; 354 if (!(attr & ARM_V7S_PTE_AP_UNPRIV)) 355 prot |= IOMMU_PRIV; 356 if ((attr & (ARM_V7S_TEX_MASK << ARM_V7S_TEX_SHIFT)) == 0) 357 prot |= IOMMU_MMIO; 358 else if (pte & ARM_V7S_ATTR_C) 359 prot |= IOMMU_CACHE; 360 if (pte & ARM_V7S_ATTR_XN(lvl)) 361 prot |= IOMMU_NOEXEC; 362 363 return prot; 364 } 365 366 static arm_v7s_iopte arm_v7s_pte_to_cont(arm_v7s_iopte pte, int lvl) 367 { 368 if (lvl == 1) { 369 pte |= ARM_V7S_CONT_SECTION; 370 } else if (lvl == 2) { 371 arm_v7s_iopte xn = pte & ARM_V7S_ATTR_XN(lvl); 372 arm_v7s_iopte tex = pte & ARM_V7S_CONT_PAGE_TEX_MASK; 373 374 pte ^= xn | tex | ARM_V7S_PTE_TYPE_PAGE; 375 pte |= (xn << ARM_V7S_CONT_PAGE_XN_SHIFT) | 376 (tex << ARM_V7S_CONT_PAGE_TEX_SHIFT) | 377 ARM_V7S_PTE_TYPE_CONT_PAGE; 378 } 379 return pte; 380 } 381 382 static arm_v7s_iopte arm_v7s_cont_to_pte(arm_v7s_iopte pte, int lvl) 383 { 384 if (lvl == 1) { 385 pte &= ~ARM_V7S_CONT_SECTION; 386 } else if (lvl == 2) { 387 arm_v7s_iopte xn = pte & BIT(ARM_V7S_CONT_PAGE_XN_SHIFT); 388 arm_v7s_iopte tex = pte & (ARM_V7S_CONT_PAGE_TEX_MASK << 389 ARM_V7S_CONT_PAGE_TEX_SHIFT); 390 391 pte ^= xn | tex | ARM_V7S_PTE_TYPE_CONT_PAGE; 392 pte |= (xn >> ARM_V7S_CONT_PAGE_XN_SHIFT) | 393 (tex >> ARM_V7S_CONT_PAGE_TEX_SHIFT) | 394 ARM_V7S_PTE_TYPE_PAGE; 395 } 396 return pte; 397 } 398 399 static bool arm_v7s_pte_is_cont(arm_v7s_iopte pte, int lvl) 400 { 401 if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte, lvl)) 402 return pte & ARM_V7S_CONT_SECTION; 403 else if (lvl == 2) 404 return !(pte & ARM_V7S_PTE_TYPE_PAGE); 405 return false; 406 } 407 408 static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *, 409 struct iommu_iotlb_gather *, unsigned long, 410 size_t, int, arm_v7s_iopte *); 411 412 static int arm_v7s_init_pte(struct arm_v7s_io_pgtable *data, 413 unsigned long iova, phys_addr_t paddr, int prot, 414 int lvl, int num_entries, arm_v7s_iopte *ptep) 415 { 416 struct io_pgtable_cfg *cfg = &data->iop.cfg; 417 arm_v7s_iopte pte; 418 int i; 419 420 for (i = 0; i < num_entries; i++) 421 if (ARM_V7S_PTE_IS_TABLE(ptep[i], lvl)) { 422 /* 423 * We need to unmap and free the old table before 424 * overwriting it with a block entry. 425 */ 426 arm_v7s_iopte *tblp; 427 size_t sz = ARM_V7S_BLOCK_SIZE(lvl); 428 429 tblp = ptep - ARM_V7S_LVL_IDX(iova, lvl); 430 if (WARN_ON(__arm_v7s_unmap(data, NULL, iova + i * sz, 431 sz, lvl, tblp) != sz)) 432 return -EINVAL; 433 } else if (ptep[i]) { 434 /* We require an unmap first */ 435 WARN_ON(!selftest_running); 436 return -EEXIST; 437 } 438 439 pte = arm_v7s_prot_to_pte(prot, lvl, cfg); 440 if (num_entries > 1) 441 pte = arm_v7s_pte_to_cont(pte, lvl); 442 443 pte |= paddr_to_iopte(paddr, lvl, cfg); 444 445 __arm_v7s_set_pte(ptep, pte, num_entries, cfg); 446 return 0; 447 } 448 449 static arm_v7s_iopte arm_v7s_install_table(arm_v7s_iopte *table, 450 arm_v7s_iopte *ptep, 451 arm_v7s_iopte curr, 452 struct io_pgtable_cfg *cfg) 453 { 454 arm_v7s_iopte old, new; 455 456 new = virt_to_phys(table) | ARM_V7S_PTE_TYPE_TABLE; 457 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS) 458 new |= ARM_V7S_ATTR_NS_TABLE; 459 460 /* 461 * Ensure the table itself is visible before its PTE can be. 462 * Whilst we could get away with cmpxchg64_release below, this 463 * doesn't have any ordering semantics when !CONFIG_SMP. 464 */ 465 dma_wmb(); 466 467 old = cmpxchg_relaxed(ptep, curr, new); 468 __arm_v7s_pte_sync(ptep, 1, cfg); 469 470 return old; 471 } 472 473 static int __arm_v7s_map(struct arm_v7s_io_pgtable *data, unsigned long iova, 474 phys_addr_t paddr, size_t size, int prot, 475 int lvl, arm_v7s_iopte *ptep) 476 { 477 struct io_pgtable_cfg *cfg = &data->iop.cfg; 478 arm_v7s_iopte pte, *cptep; 479 int num_entries = size >> ARM_V7S_LVL_SHIFT(lvl); 480 481 /* Find our entry at the current level */ 482 ptep += ARM_V7S_LVL_IDX(iova, lvl); 483 484 /* If we can install a leaf entry at this level, then do so */ 485 if (num_entries) 486 return arm_v7s_init_pte(data, iova, paddr, prot, 487 lvl, num_entries, ptep); 488 489 /* We can't allocate tables at the final level */ 490 if (WARN_ON(lvl == 2)) 491 return -EINVAL; 492 493 /* Grab a pointer to the next level */ 494 pte = READ_ONCE(*ptep); 495 if (!pte) { 496 cptep = __arm_v7s_alloc_table(lvl + 1, GFP_ATOMIC, data); 497 if (!cptep) 498 return -ENOMEM; 499 500 pte = arm_v7s_install_table(cptep, ptep, 0, cfg); 501 if (pte) 502 __arm_v7s_free_table(cptep, lvl + 1, data); 503 } else { 504 /* We've no easy way of knowing if it's synced yet, so... */ 505 __arm_v7s_pte_sync(ptep, 1, cfg); 506 } 507 508 if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) { 509 cptep = iopte_deref(pte, lvl, data); 510 } else if (pte) { 511 /* We require an unmap first */ 512 WARN_ON(!selftest_running); 513 return -EEXIST; 514 } 515 516 /* Rinse, repeat */ 517 return __arm_v7s_map(data, iova, paddr, size, prot, lvl + 1, cptep); 518 } 519 520 static int arm_v7s_map(struct io_pgtable_ops *ops, unsigned long iova, 521 phys_addr_t paddr, size_t size, int prot) 522 { 523 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); 524 struct io_pgtable *iop = &data->iop; 525 int ret; 526 527 /* If no access, then nothing to do */ 528 if (!(prot & (IOMMU_READ | IOMMU_WRITE))) 529 return 0; 530 531 if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias) || 532 paddr >= (1ULL << data->iop.cfg.oas))) 533 return -ERANGE; 534 535 ret = __arm_v7s_map(data, iova, paddr, size, prot, 1, data->pgd); 536 /* 537 * Synchronise all PTE updates for the new mapping before there's 538 * a chance for anything to kick off a table walk for the new iova. 539 */ 540 if (iop->cfg.quirks & IO_PGTABLE_QUIRK_TLBI_ON_MAP) { 541 io_pgtable_tlb_flush_walk(iop, iova, size, 542 ARM_V7S_BLOCK_SIZE(2)); 543 } else { 544 wmb(); 545 } 546 547 return ret; 548 } 549 550 static void arm_v7s_free_pgtable(struct io_pgtable *iop) 551 { 552 struct arm_v7s_io_pgtable *data = io_pgtable_to_data(iop); 553 int i; 554 555 for (i = 0; i < ARM_V7S_PTES_PER_LVL(1); i++) { 556 arm_v7s_iopte pte = data->pgd[i]; 557 558 if (ARM_V7S_PTE_IS_TABLE(pte, 1)) 559 __arm_v7s_free_table(iopte_deref(pte, 1, data), 560 2, data); 561 } 562 __arm_v7s_free_table(data->pgd, 1, data); 563 kmem_cache_destroy(data->l2_tables); 564 kfree(data); 565 } 566 567 static arm_v7s_iopte arm_v7s_split_cont(struct arm_v7s_io_pgtable *data, 568 unsigned long iova, int idx, int lvl, 569 arm_v7s_iopte *ptep) 570 { 571 struct io_pgtable *iop = &data->iop; 572 arm_v7s_iopte pte; 573 size_t size = ARM_V7S_BLOCK_SIZE(lvl); 574 int i; 575 576 /* Check that we didn't lose a race to get the lock */ 577 pte = *ptep; 578 if (!arm_v7s_pte_is_cont(pte, lvl)) 579 return pte; 580 581 ptep -= idx & (ARM_V7S_CONT_PAGES - 1); 582 pte = arm_v7s_cont_to_pte(pte, lvl); 583 for (i = 0; i < ARM_V7S_CONT_PAGES; i++) 584 ptep[i] = pte + i * size; 585 586 __arm_v7s_pte_sync(ptep, ARM_V7S_CONT_PAGES, &iop->cfg); 587 588 size *= ARM_V7S_CONT_PAGES; 589 io_pgtable_tlb_flush_leaf(iop, iova, size, size); 590 return pte; 591 } 592 593 static size_t arm_v7s_split_blk_unmap(struct arm_v7s_io_pgtable *data, 594 struct iommu_iotlb_gather *gather, 595 unsigned long iova, size_t size, 596 arm_v7s_iopte blk_pte, 597 arm_v7s_iopte *ptep) 598 { 599 struct io_pgtable_cfg *cfg = &data->iop.cfg; 600 arm_v7s_iopte pte, *tablep; 601 int i, unmap_idx, num_entries, num_ptes; 602 603 tablep = __arm_v7s_alloc_table(2, GFP_ATOMIC, data); 604 if (!tablep) 605 return 0; /* Bytes unmapped */ 606 607 num_ptes = ARM_V7S_PTES_PER_LVL(2); 608 num_entries = size >> ARM_V7S_LVL_SHIFT(2); 609 unmap_idx = ARM_V7S_LVL_IDX(iova, 2); 610 611 pte = arm_v7s_prot_to_pte(arm_v7s_pte_to_prot(blk_pte, 1), 2, cfg); 612 if (num_entries > 1) 613 pte = arm_v7s_pte_to_cont(pte, 2); 614 615 for (i = 0; i < num_ptes; i += num_entries, pte += size) { 616 /* Unmap! */ 617 if (i == unmap_idx) 618 continue; 619 620 __arm_v7s_set_pte(&tablep[i], pte, num_entries, cfg); 621 } 622 623 pte = arm_v7s_install_table(tablep, ptep, blk_pte, cfg); 624 if (pte != blk_pte) { 625 __arm_v7s_free_table(tablep, 2, data); 626 627 if (!ARM_V7S_PTE_IS_TABLE(pte, 1)) 628 return 0; 629 630 tablep = iopte_deref(pte, 1, data); 631 return __arm_v7s_unmap(data, gather, iova, size, 2, tablep); 632 } 633 634 io_pgtable_tlb_add_page(&data->iop, gather, iova, size); 635 return size; 636 } 637 638 static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *data, 639 struct iommu_iotlb_gather *gather, 640 unsigned long iova, size_t size, int lvl, 641 arm_v7s_iopte *ptep) 642 { 643 arm_v7s_iopte pte[ARM_V7S_CONT_PAGES]; 644 struct io_pgtable *iop = &data->iop; 645 int idx, i = 0, num_entries = size >> ARM_V7S_LVL_SHIFT(lvl); 646 647 /* Something went horribly wrong and we ran out of page table */ 648 if (WARN_ON(lvl > 2)) 649 return 0; 650 651 idx = ARM_V7S_LVL_IDX(iova, lvl); 652 ptep += idx; 653 do { 654 pte[i] = READ_ONCE(ptep[i]); 655 if (WARN_ON(!ARM_V7S_PTE_IS_VALID(pte[i]))) 656 return 0; 657 } while (++i < num_entries); 658 659 /* 660 * If we've hit a contiguous 'large page' entry at this level, it 661 * needs splitting first, unless we're unmapping the whole lot. 662 * 663 * For splitting, we can't rewrite 16 PTEs atomically, and since we 664 * can't necessarily assume TEX remap we don't have a software bit to 665 * mark live entries being split. In practice (i.e. DMA API code), we 666 * will never be splitting large pages anyway, so just wrap this edge 667 * case in a lock for the sake of correctness and be done with it. 668 */ 669 if (num_entries <= 1 && arm_v7s_pte_is_cont(pte[0], lvl)) { 670 unsigned long flags; 671 672 spin_lock_irqsave(&data->split_lock, flags); 673 pte[0] = arm_v7s_split_cont(data, iova, idx, lvl, ptep); 674 spin_unlock_irqrestore(&data->split_lock, flags); 675 } 676 677 /* If the size matches this level, we're in the right place */ 678 if (num_entries) { 679 size_t blk_size = ARM_V7S_BLOCK_SIZE(lvl); 680 681 __arm_v7s_set_pte(ptep, 0, num_entries, &iop->cfg); 682 683 for (i = 0; i < num_entries; i++) { 684 if (ARM_V7S_PTE_IS_TABLE(pte[i], lvl)) { 685 /* Also flush any partial walks */ 686 io_pgtable_tlb_flush_walk(iop, iova, blk_size, 687 ARM_V7S_BLOCK_SIZE(lvl + 1)); 688 ptep = iopte_deref(pte[i], lvl, data); 689 __arm_v7s_free_table(ptep, lvl + 1, data); 690 } else if (iop->cfg.quirks & IO_PGTABLE_QUIRK_NON_STRICT) { 691 /* 692 * Order the PTE update against queueing the IOVA, to 693 * guarantee that a flush callback from a different CPU 694 * has observed it before the TLBIALL can be issued. 695 */ 696 smp_wmb(); 697 } else { 698 io_pgtable_tlb_add_page(iop, gather, iova, blk_size); 699 } 700 iova += blk_size; 701 } 702 return size; 703 } else if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte[0], lvl)) { 704 /* 705 * Insert a table at the next level to map the old region, 706 * minus the part we want to unmap 707 */ 708 return arm_v7s_split_blk_unmap(data, gather, iova, size, pte[0], 709 ptep); 710 } 711 712 /* Keep on walkin' */ 713 ptep = iopte_deref(pte[0], lvl, data); 714 return __arm_v7s_unmap(data, gather, iova, size, lvl + 1, ptep); 715 } 716 717 static size_t arm_v7s_unmap(struct io_pgtable_ops *ops, unsigned long iova, 718 size_t size, struct iommu_iotlb_gather *gather) 719 { 720 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); 721 722 if (WARN_ON(upper_32_bits(iova))) 723 return 0; 724 725 return __arm_v7s_unmap(data, gather, iova, size, 1, data->pgd); 726 } 727 728 static phys_addr_t arm_v7s_iova_to_phys(struct io_pgtable_ops *ops, 729 unsigned long iova) 730 { 731 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); 732 arm_v7s_iopte *ptep = data->pgd, pte; 733 int lvl = 0; 734 u32 mask; 735 736 do { 737 ptep += ARM_V7S_LVL_IDX(iova, ++lvl); 738 pte = READ_ONCE(*ptep); 739 ptep = iopte_deref(pte, lvl, data); 740 } while (ARM_V7S_PTE_IS_TABLE(pte, lvl)); 741 742 if (!ARM_V7S_PTE_IS_VALID(pte)) 743 return 0; 744 745 mask = ARM_V7S_LVL_MASK(lvl); 746 if (arm_v7s_pte_is_cont(pte, lvl)) 747 mask *= ARM_V7S_CONT_PAGES; 748 return iopte_to_paddr(pte, lvl, &data->iop.cfg) | (iova & ~mask); 749 } 750 751 static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, 752 void *cookie) 753 { 754 struct arm_v7s_io_pgtable *data; 755 756 if (cfg->ias > ARM_V7S_ADDR_BITS) 757 return NULL; 758 759 if (cfg->oas > (arm_v7s_is_mtk_enabled(cfg) ? 34 : ARM_V7S_ADDR_BITS)) 760 return NULL; 761 762 if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | 763 IO_PGTABLE_QUIRK_NO_PERMS | 764 IO_PGTABLE_QUIRK_TLBI_ON_MAP | 765 IO_PGTABLE_QUIRK_ARM_MTK_EXT | 766 IO_PGTABLE_QUIRK_NON_STRICT)) 767 return NULL; 768 769 /* If ARM_MTK_4GB is enabled, the NO_PERMS is also expected. */ 770 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT && 771 !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS)) 772 return NULL; 773 774 data = kmalloc(sizeof(*data), GFP_KERNEL); 775 if (!data) 776 return NULL; 777 778 spin_lock_init(&data->split_lock); 779 data->l2_tables = kmem_cache_create("io-pgtable_armv7s_l2", 780 ARM_V7S_TABLE_SIZE(2), 781 ARM_V7S_TABLE_SIZE(2), 782 ARM_V7S_TABLE_SLAB_FLAGS, NULL); 783 if (!data->l2_tables) 784 goto out_free_data; 785 786 data->iop.ops = (struct io_pgtable_ops) { 787 .map = arm_v7s_map, 788 .unmap = arm_v7s_unmap, 789 .iova_to_phys = arm_v7s_iova_to_phys, 790 }; 791 792 /* We have to do this early for __arm_v7s_alloc_table to work... */ 793 data->iop.cfg = *cfg; 794 795 /* 796 * Unless the IOMMU driver indicates supersection support by 797 * having SZ_16M set in the initial bitmap, they won't be used. 798 */ 799 cfg->pgsize_bitmap &= SZ_4K | SZ_64K | SZ_1M | SZ_16M; 800 801 /* TCR: T0SZ=0, disable TTBR1 */ 802 cfg->arm_v7s_cfg.tcr = ARM_V7S_TCR_PD1; 803 804 /* 805 * TEX remap: the indices used map to the closest equivalent types 806 * under the non-TEX-remap interpretation of those attribute bits, 807 * excepting various implementation-defined aspects of shareability. 808 */ 809 cfg->arm_v7s_cfg.prrr = ARM_V7S_PRRR_TR(1, ARM_V7S_PRRR_TYPE_DEVICE) | 810 ARM_V7S_PRRR_TR(4, ARM_V7S_PRRR_TYPE_NORMAL) | 811 ARM_V7S_PRRR_TR(7, ARM_V7S_PRRR_TYPE_NORMAL) | 812 ARM_V7S_PRRR_DS0 | ARM_V7S_PRRR_DS1 | 813 ARM_V7S_PRRR_NS1 | ARM_V7S_PRRR_NOS(7); 814 cfg->arm_v7s_cfg.nmrr = ARM_V7S_NMRR_IR(7, ARM_V7S_RGN_WBWA) | 815 ARM_V7S_NMRR_OR(7, ARM_V7S_RGN_WBWA); 816 817 /* Looking good; allocate a pgd */ 818 data->pgd = __arm_v7s_alloc_table(1, GFP_KERNEL, data); 819 if (!data->pgd) 820 goto out_free_data; 821 822 /* Ensure the empty pgd is visible before any actual TTBR write */ 823 wmb(); 824 825 /* TTBRs */ 826 cfg->arm_v7s_cfg.ttbr[0] = virt_to_phys(data->pgd) | 827 ARM_V7S_TTBR_S | ARM_V7S_TTBR_NOS | 828 (cfg->coherent_walk ? 829 (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) | 830 ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) : 831 (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) | 832 ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC))); 833 cfg->arm_v7s_cfg.ttbr[1] = 0; 834 return &data->iop; 835 836 out_free_data: 837 kmem_cache_destroy(data->l2_tables); 838 kfree(data); 839 return NULL; 840 } 841 842 struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = { 843 .alloc = arm_v7s_alloc_pgtable, 844 .free = arm_v7s_free_pgtable, 845 }; 846 847 #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST 848 849 static struct io_pgtable_cfg *cfg_cookie; 850 851 static void dummy_tlb_flush_all(void *cookie) 852 { 853 WARN_ON(cookie != cfg_cookie); 854 } 855 856 static void dummy_tlb_flush(unsigned long iova, size_t size, size_t granule, 857 void *cookie) 858 { 859 WARN_ON(cookie != cfg_cookie); 860 WARN_ON(!(size & cfg_cookie->pgsize_bitmap)); 861 } 862 863 static void dummy_tlb_add_page(struct iommu_iotlb_gather *gather, 864 unsigned long iova, size_t granule, void *cookie) 865 { 866 dummy_tlb_flush(iova, granule, granule, cookie); 867 } 868 869 static const struct iommu_flush_ops dummy_tlb_ops = { 870 .tlb_flush_all = dummy_tlb_flush_all, 871 .tlb_flush_walk = dummy_tlb_flush, 872 .tlb_flush_leaf = dummy_tlb_flush, 873 .tlb_add_page = dummy_tlb_add_page, 874 }; 875 876 #define __FAIL(ops) ({ \ 877 WARN(1, "selftest: test failed\n"); \ 878 selftest_running = false; \ 879 -EFAULT; \ 880 }) 881 882 static int __init arm_v7s_do_selftests(void) 883 { 884 struct io_pgtable_ops *ops; 885 struct io_pgtable_cfg cfg = { 886 .tlb = &dummy_tlb_ops, 887 .oas = 32, 888 .ias = 32, 889 .coherent_walk = true, 890 .quirks = IO_PGTABLE_QUIRK_ARM_NS, 891 .pgsize_bitmap = SZ_4K | SZ_64K | SZ_1M | SZ_16M, 892 }; 893 unsigned int iova, size, iova_start; 894 unsigned int i, loopnr = 0; 895 896 selftest_running = true; 897 898 cfg_cookie = &cfg; 899 900 ops = alloc_io_pgtable_ops(ARM_V7S, &cfg, &cfg); 901 if (!ops) { 902 pr_err("selftest: failed to allocate io pgtable ops\n"); 903 return -EINVAL; 904 } 905 906 /* 907 * Initial sanity checks. 908 * Empty page tables shouldn't provide any translations. 909 */ 910 if (ops->iova_to_phys(ops, 42)) 911 return __FAIL(ops); 912 913 if (ops->iova_to_phys(ops, SZ_1G + 42)) 914 return __FAIL(ops); 915 916 if (ops->iova_to_phys(ops, SZ_2G + 42)) 917 return __FAIL(ops); 918 919 /* 920 * Distinct mappings of different granule sizes. 921 */ 922 iova = 0; 923 for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) { 924 size = 1UL << i; 925 if (ops->map(ops, iova, iova, size, IOMMU_READ | 926 IOMMU_WRITE | 927 IOMMU_NOEXEC | 928 IOMMU_CACHE)) 929 return __FAIL(ops); 930 931 /* Overlapping mappings */ 932 if (!ops->map(ops, iova, iova + size, size, 933 IOMMU_READ | IOMMU_NOEXEC)) 934 return __FAIL(ops); 935 936 if (ops->iova_to_phys(ops, iova + 42) != (iova + 42)) 937 return __FAIL(ops); 938 939 iova += SZ_16M; 940 loopnr++; 941 } 942 943 /* Partial unmap */ 944 i = 1; 945 size = 1UL << __ffs(cfg.pgsize_bitmap); 946 while (i < loopnr) { 947 iova_start = i * SZ_16M; 948 if (ops->unmap(ops, iova_start + size, size, NULL) != size) 949 return __FAIL(ops); 950 951 /* Remap of partial unmap */ 952 if (ops->map(ops, iova_start + size, size, size, IOMMU_READ)) 953 return __FAIL(ops); 954 955 if (ops->iova_to_phys(ops, iova_start + size + 42) 956 != (size + 42)) 957 return __FAIL(ops); 958 i++; 959 } 960 961 /* Full unmap */ 962 iova = 0; 963 for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) { 964 size = 1UL << i; 965 966 if (ops->unmap(ops, iova, size, NULL) != size) 967 return __FAIL(ops); 968 969 if (ops->iova_to_phys(ops, iova + 42)) 970 return __FAIL(ops); 971 972 /* Remap full block */ 973 if (ops->map(ops, iova, iova, size, IOMMU_WRITE)) 974 return __FAIL(ops); 975 976 if (ops->iova_to_phys(ops, iova + 42) != (iova + 42)) 977 return __FAIL(ops); 978 979 iova += SZ_16M; 980 } 981 982 free_io_pgtable_ops(ops); 983 984 selftest_running = false; 985 986 pr_info("self test ok\n"); 987 return 0; 988 } 989 subsys_initcall(arm_v7s_do_selftests); 990 #endif 991