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. 48 * MediaTek extend 2 bits to reach 34bits, 14 bits at lvl1 and 8 bits at lvl2. 49 */ 50 #define ARM_V7S_ADDR_BITS 32 51 #define _ARM_V7S_LVL_BITS(lvl, cfg) ((lvl) == 1 ? ((cfg)->ias - 20) : 8) 52 #define ARM_V7S_LVL_SHIFT(lvl) ((lvl) == 1 ? 20 : 12) 53 #define ARM_V7S_TABLE_SHIFT 10 54 55 #define ARM_V7S_PTES_PER_LVL(lvl, cfg) (1 << _ARM_V7S_LVL_BITS(lvl, cfg)) 56 #define ARM_V7S_TABLE_SIZE(lvl, cfg) \ 57 (ARM_V7S_PTES_PER_LVL(lvl, cfg) * sizeof(arm_v7s_iopte)) 58 59 #define ARM_V7S_BLOCK_SIZE(lvl) (1UL << ARM_V7S_LVL_SHIFT(lvl)) 60 #define ARM_V7S_LVL_MASK(lvl) ((u32)(~0U << ARM_V7S_LVL_SHIFT(lvl))) 61 #define ARM_V7S_TABLE_MASK ((u32)(~0U << ARM_V7S_TABLE_SHIFT)) 62 #define _ARM_V7S_IDX_MASK(lvl, cfg) (ARM_V7S_PTES_PER_LVL(lvl, cfg) - 1) 63 #define ARM_V7S_LVL_IDX(addr, lvl, cfg) ({ \ 64 int _l = lvl; \ 65 ((addr) >> ARM_V7S_LVL_SHIFT(_l)) & _ARM_V7S_IDX_MASK(_l, cfg); \ 66 }) 67 68 /* 69 * Large page/supersection entries are effectively a block of 16 page/section 70 * entries, along the lines of the LPAE contiguous hint, but all with the 71 * same output address. For want of a better common name we'll call them 72 * "contiguous" versions of their respective page/section entries here, but 73 * noting the distinction (WRT to TLB maintenance) that they represent *one* 74 * entry repeated 16 times, not 16 separate entries (as in the LPAE case). 75 */ 76 #define ARM_V7S_CONT_PAGES 16 77 78 /* PTE type bits: these are all mixed up with XN/PXN bits in most cases */ 79 #define ARM_V7S_PTE_TYPE_TABLE 0x1 80 #define ARM_V7S_PTE_TYPE_PAGE 0x2 81 #define ARM_V7S_PTE_TYPE_CONT_PAGE 0x1 82 83 #define ARM_V7S_PTE_IS_VALID(pte) (((pte) & 0x3) != 0) 84 #define ARM_V7S_PTE_IS_TABLE(pte, lvl) \ 85 ((lvl) == 1 && (((pte) & 0x3) == ARM_V7S_PTE_TYPE_TABLE)) 86 87 /* Page table bits */ 88 #define ARM_V7S_ATTR_XN(lvl) BIT(4 * (2 - (lvl))) 89 #define ARM_V7S_ATTR_B BIT(2) 90 #define ARM_V7S_ATTR_C BIT(3) 91 #define ARM_V7S_ATTR_NS_TABLE BIT(3) 92 #define ARM_V7S_ATTR_NS_SECTION BIT(19) 93 94 #define ARM_V7S_CONT_SECTION BIT(18) 95 #define ARM_V7S_CONT_PAGE_XN_SHIFT 15 96 97 /* 98 * The attribute bits are consistently ordered*, but occupy bits [17:10] of 99 * a level 1 PTE vs. bits [11:4] at level 2. Thus we define the individual 100 * fields relative to that 8-bit block, plus a total shift relative to the PTE. 101 */ 102 #define ARM_V7S_ATTR_SHIFT(lvl) (16 - (lvl) * 6) 103 104 #define ARM_V7S_ATTR_MASK 0xff 105 #define ARM_V7S_ATTR_AP0 BIT(0) 106 #define ARM_V7S_ATTR_AP1 BIT(1) 107 #define ARM_V7S_ATTR_AP2 BIT(5) 108 #define ARM_V7S_ATTR_S BIT(6) 109 #define ARM_V7S_ATTR_NG BIT(7) 110 #define ARM_V7S_TEX_SHIFT 2 111 #define ARM_V7S_TEX_MASK 0x7 112 #define ARM_V7S_ATTR_TEX(val) (((val) & ARM_V7S_TEX_MASK) << ARM_V7S_TEX_SHIFT) 113 114 /* MediaTek extend the bits below for PA 32bit/33bit/34bit */ 115 #define ARM_V7S_ATTR_MTK_PA_BIT32 BIT(9) 116 #define ARM_V7S_ATTR_MTK_PA_BIT33 BIT(4) 117 #define ARM_V7S_ATTR_MTK_PA_BIT34 BIT(5) 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 to_mtk_iopte(phys_addr_t paddr, arm_v7s_iopte pte) 186 { 187 if (paddr & BIT_ULL(32)) 188 pte |= ARM_V7S_ATTR_MTK_PA_BIT32; 189 if (paddr & BIT_ULL(33)) 190 pte |= ARM_V7S_ATTR_MTK_PA_BIT33; 191 if (paddr & BIT_ULL(34)) 192 pte |= ARM_V7S_ATTR_MTK_PA_BIT34; 193 return pte; 194 } 195 196 static arm_v7s_iopte paddr_to_iopte(phys_addr_t paddr, int lvl, 197 struct io_pgtable_cfg *cfg) 198 { 199 arm_v7s_iopte pte = paddr & ARM_V7S_LVL_MASK(lvl); 200 201 if (arm_v7s_is_mtk_enabled(cfg)) 202 return to_mtk_iopte(paddr, pte); 203 204 return pte; 205 } 206 207 static phys_addr_t iopte_to_paddr(arm_v7s_iopte pte, int lvl, 208 struct io_pgtable_cfg *cfg) 209 { 210 arm_v7s_iopte mask; 211 phys_addr_t paddr; 212 213 if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) 214 mask = ARM_V7S_TABLE_MASK; 215 else if (arm_v7s_pte_is_cont(pte, lvl)) 216 mask = ARM_V7S_LVL_MASK(lvl) * ARM_V7S_CONT_PAGES; 217 else 218 mask = ARM_V7S_LVL_MASK(lvl); 219 220 paddr = pte & mask; 221 if (!arm_v7s_is_mtk_enabled(cfg)) 222 return paddr; 223 224 if (pte & ARM_V7S_ATTR_MTK_PA_BIT32) 225 paddr |= BIT_ULL(32); 226 if (pte & ARM_V7S_ATTR_MTK_PA_BIT33) 227 paddr |= BIT_ULL(33); 228 if (pte & ARM_V7S_ATTR_MTK_PA_BIT34) 229 paddr |= BIT_ULL(34); 230 return paddr; 231 } 232 233 static arm_v7s_iopte *iopte_deref(arm_v7s_iopte pte, int lvl, 234 struct arm_v7s_io_pgtable *data) 235 { 236 return phys_to_virt(iopte_to_paddr(pte, lvl, &data->iop.cfg)); 237 } 238 239 static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, 240 struct arm_v7s_io_pgtable *data) 241 { 242 struct io_pgtable_cfg *cfg = &data->iop.cfg; 243 struct device *dev = cfg->iommu_dev; 244 phys_addr_t phys; 245 dma_addr_t dma; 246 size_t size = ARM_V7S_TABLE_SIZE(lvl, cfg); 247 void *table = NULL; 248 gfp_t gfp_l1; 249 250 /* 251 * ARM_MTK_TTBR_EXT extend the translation table base support larger 252 * memory address. 253 */ 254 gfp_l1 = cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT ? 255 GFP_KERNEL : ARM_V7S_TABLE_GFP_DMA; 256 257 if (lvl == 1) 258 table = (void *)__get_free_pages(gfp_l1 | __GFP_ZERO, get_order(size)); 259 else if (lvl == 2) 260 table = kmem_cache_zalloc(data->l2_tables, gfp); 261 262 if (!table) 263 return NULL; 264 265 phys = virt_to_phys(table); 266 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT ? 267 phys >= (1ULL << cfg->oas) : phys != (arm_v7s_iopte)phys) { 268 /* Doesn't fit in PTE */ 269 dev_err(dev, "Page table does not fit in PTE: %pa", &phys); 270 goto out_free; 271 } 272 if (!cfg->coherent_walk) { 273 dma = dma_map_single(dev, table, size, DMA_TO_DEVICE); 274 if (dma_mapping_error(dev, dma)) 275 goto out_free; 276 /* 277 * We depend on the IOMMU being able to work with any physical 278 * address directly, so if the DMA layer suggests otherwise by 279 * translating or truncating them, that bodes very badly... 280 */ 281 if (dma != phys) 282 goto out_unmap; 283 } 284 if (lvl == 2) 285 kmemleak_ignore(table); 286 return table; 287 288 out_unmap: 289 dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n"); 290 dma_unmap_single(dev, dma, size, DMA_TO_DEVICE); 291 out_free: 292 if (lvl == 1) 293 free_pages((unsigned long)table, get_order(size)); 294 else 295 kmem_cache_free(data->l2_tables, table); 296 return NULL; 297 } 298 299 static void __arm_v7s_free_table(void *table, int lvl, 300 struct arm_v7s_io_pgtable *data) 301 { 302 struct io_pgtable_cfg *cfg = &data->iop.cfg; 303 struct device *dev = cfg->iommu_dev; 304 size_t size = ARM_V7S_TABLE_SIZE(lvl, cfg); 305 306 if (!cfg->coherent_walk) 307 dma_unmap_single(dev, __arm_v7s_dma_addr(table), size, 308 DMA_TO_DEVICE); 309 if (lvl == 1) 310 free_pages((unsigned long)table, get_order(size)); 311 else 312 kmem_cache_free(data->l2_tables, table); 313 } 314 315 static void __arm_v7s_pte_sync(arm_v7s_iopte *ptep, int num_entries, 316 struct io_pgtable_cfg *cfg) 317 { 318 if (cfg->coherent_walk) 319 return; 320 321 dma_sync_single_for_device(cfg->iommu_dev, __arm_v7s_dma_addr(ptep), 322 num_entries * sizeof(*ptep), DMA_TO_DEVICE); 323 } 324 static void __arm_v7s_set_pte(arm_v7s_iopte *ptep, arm_v7s_iopte pte, 325 int num_entries, struct io_pgtable_cfg *cfg) 326 { 327 int i; 328 329 for (i = 0; i < num_entries; i++) 330 ptep[i] = pte; 331 332 __arm_v7s_pte_sync(ptep, num_entries, cfg); 333 } 334 335 static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl, 336 struct io_pgtable_cfg *cfg) 337 { 338 bool ap = !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS); 339 arm_v7s_iopte pte = ARM_V7S_ATTR_NG | ARM_V7S_ATTR_S; 340 341 if (!(prot & IOMMU_MMIO)) 342 pte |= ARM_V7S_ATTR_TEX(1); 343 if (ap) { 344 pte |= ARM_V7S_PTE_AF; 345 if (!(prot & IOMMU_PRIV)) 346 pte |= ARM_V7S_PTE_AP_UNPRIV; 347 if (!(prot & IOMMU_WRITE)) 348 pte |= ARM_V7S_PTE_AP_RDONLY; 349 } 350 pte <<= ARM_V7S_ATTR_SHIFT(lvl); 351 352 if ((prot & IOMMU_NOEXEC) && ap) 353 pte |= ARM_V7S_ATTR_XN(lvl); 354 if (prot & IOMMU_MMIO) 355 pte |= ARM_V7S_ATTR_B; 356 else if (prot & IOMMU_CACHE) 357 pte |= ARM_V7S_ATTR_B | ARM_V7S_ATTR_C; 358 359 pte |= ARM_V7S_PTE_TYPE_PAGE; 360 if (lvl == 1 && (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)) 361 pte |= ARM_V7S_ATTR_NS_SECTION; 362 363 return pte; 364 } 365 366 static int arm_v7s_pte_to_prot(arm_v7s_iopte pte, int lvl) 367 { 368 int prot = IOMMU_READ; 369 arm_v7s_iopte attr = pte >> ARM_V7S_ATTR_SHIFT(lvl); 370 371 if (!(attr & ARM_V7S_PTE_AP_RDONLY)) 372 prot |= IOMMU_WRITE; 373 if (!(attr & ARM_V7S_PTE_AP_UNPRIV)) 374 prot |= IOMMU_PRIV; 375 if ((attr & (ARM_V7S_TEX_MASK << ARM_V7S_TEX_SHIFT)) == 0) 376 prot |= IOMMU_MMIO; 377 else if (pte & ARM_V7S_ATTR_C) 378 prot |= IOMMU_CACHE; 379 if (pte & ARM_V7S_ATTR_XN(lvl)) 380 prot |= IOMMU_NOEXEC; 381 382 return prot; 383 } 384 385 static arm_v7s_iopte arm_v7s_pte_to_cont(arm_v7s_iopte pte, int lvl) 386 { 387 if (lvl == 1) { 388 pte |= ARM_V7S_CONT_SECTION; 389 } else if (lvl == 2) { 390 arm_v7s_iopte xn = pte & ARM_V7S_ATTR_XN(lvl); 391 arm_v7s_iopte tex = pte & ARM_V7S_CONT_PAGE_TEX_MASK; 392 393 pte ^= xn | tex | ARM_V7S_PTE_TYPE_PAGE; 394 pte |= (xn << ARM_V7S_CONT_PAGE_XN_SHIFT) | 395 (tex << ARM_V7S_CONT_PAGE_TEX_SHIFT) | 396 ARM_V7S_PTE_TYPE_CONT_PAGE; 397 } 398 return pte; 399 } 400 401 static arm_v7s_iopte arm_v7s_cont_to_pte(arm_v7s_iopte pte, int lvl) 402 { 403 if (lvl == 1) { 404 pte &= ~ARM_V7S_CONT_SECTION; 405 } else if (lvl == 2) { 406 arm_v7s_iopte xn = pte & BIT(ARM_V7S_CONT_PAGE_XN_SHIFT); 407 arm_v7s_iopte tex = pte & (ARM_V7S_CONT_PAGE_TEX_MASK << 408 ARM_V7S_CONT_PAGE_TEX_SHIFT); 409 410 pte ^= xn | tex | ARM_V7S_PTE_TYPE_CONT_PAGE; 411 pte |= (xn >> ARM_V7S_CONT_PAGE_XN_SHIFT) | 412 (tex >> ARM_V7S_CONT_PAGE_TEX_SHIFT) | 413 ARM_V7S_PTE_TYPE_PAGE; 414 } 415 return pte; 416 } 417 418 static bool arm_v7s_pte_is_cont(arm_v7s_iopte pte, int lvl) 419 { 420 if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte, lvl)) 421 return pte & ARM_V7S_CONT_SECTION; 422 else if (lvl == 2) 423 return !(pte & ARM_V7S_PTE_TYPE_PAGE); 424 return false; 425 } 426 427 static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *, 428 struct iommu_iotlb_gather *, unsigned long, 429 size_t, int, arm_v7s_iopte *); 430 431 static int arm_v7s_init_pte(struct arm_v7s_io_pgtable *data, 432 unsigned long iova, phys_addr_t paddr, int prot, 433 int lvl, int num_entries, arm_v7s_iopte *ptep) 434 { 435 struct io_pgtable_cfg *cfg = &data->iop.cfg; 436 arm_v7s_iopte pte; 437 int i; 438 439 for (i = 0; i < num_entries; i++) 440 if (ARM_V7S_PTE_IS_TABLE(ptep[i], lvl)) { 441 /* 442 * We need to unmap and free the old table before 443 * overwriting it with a block entry. 444 */ 445 arm_v7s_iopte *tblp; 446 size_t sz = ARM_V7S_BLOCK_SIZE(lvl); 447 448 tblp = ptep - ARM_V7S_LVL_IDX(iova, lvl, cfg); 449 if (WARN_ON(__arm_v7s_unmap(data, NULL, iova + i * sz, 450 sz, lvl, tblp) != sz)) 451 return -EINVAL; 452 } else if (ptep[i]) { 453 /* We require an unmap first */ 454 WARN_ON(!selftest_running); 455 return -EEXIST; 456 } 457 458 pte = arm_v7s_prot_to_pte(prot, lvl, cfg); 459 if (num_entries > 1) 460 pte = arm_v7s_pte_to_cont(pte, lvl); 461 462 pte |= paddr_to_iopte(paddr, lvl, cfg); 463 464 __arm_v7s_set_pte(ptep, pte, num_entries, cfg); 465 return 0; 466 } 467 468 static arm_v7s_iopte arm_v7s_install_table(arm_v7s_iopte *table, 469 arm_v7s_iopte *ptep, 470 arm_v7s_iopte curr, 471 struct io_pgtable_cfg *cfg) 472 { 473 phys_addr_t phys = virt_to_phys(table); 474 arm_v7s_iopte old, new; 475 476 new = phys | ARM_V7S_PTE_TYPE_TABLE; 477 478 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT) 479 new = to_mtk_iopte(phys, new); 480 481 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS) 482 new |= ARM_V7S_ATTR_NS_TABLE; 483 484 /* 485 * Ensure the table itself is visible before its PTE can be. 486 * Whilst we could get away with cmpxchg64_release below, this 487 * doesn't have any ordering semantics when !CONFIG_SMP. 488 */ 489 dma_wmb(); 490 491 old = cmpxchg_relaxed(ptep, curr, new); 492 __arm_v7s_pte_sync(ptep, 1, cfg); 493 494 return old; 495 } 496 497 static int __arm_v7s_map(struct arm_v7s_io_pgtable *data, unsigned long iova, 498 phys_addr_t paddr, size_t size, int prot, 499 int lvl, arm_v7s_iopte *ptep, gfp_t gfp) 500 { 501 struct io_pgtable_cfg *cfg = &data->iop.cfg; 502 arm_v7s_iopte pte, *cptep; 503 int num_entries = size >> ARM_V7S_LVL_SHIFT(lvl); 504 505 /* Find our entry at the current level */ 506 ptep += ARM_V7S_LVL_IDX(iova, lvl, cfg); 507 508 /* If we can install a leaf entry at this level, then do so */ 509 if (num_entries) 510 return arm_v7s_init_pte(data, iova, paddr, prot, 511 lvl, num_entries, ptep); 512 513 /* We can't allocate tables at the final level */ 514 if (WARN_ON(lvl == 2)) 515 return -EINVAL; 516 517 /* Grab a pointer to the next level */ 518 pte = READ_ONCE(*ptep); 519 if (!pte) { 520 cptep = __arm_v7s_alloc_table(lvl + 1, gfp, data); 521 if (!cptep) 522 return -ENOMEM; 523 524 pte = arm_v7s_install_table(cptep, ptep, 0, cfg); 525 if (pte) 526 __arm_v7s_free_table(cptep, lvl + 1, data); 527 } else { 528 /* We've no easy way of knowing if it's synced yet, so... */ 529 __arm_v7s_pte_sync(ptep, 1, cfg); 530 } 531 532 if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) { 533 cptep = iopte_deref(pte, lvl, data); 534 } else if (pte) { 535 /* We require an unmap first */ 536 WARN_ON(!selftest_running); 537 return -EEXIST; 538 } 539 540 /* Rinse, repeat */ 541 return __arm_v7s_map(data, iova, paddr, size, prot, lvl + 1, cptep, gfp); 542 } 543 544 static int arm_v7s_map_pages(struct io_pgtable_ops *ops, unsigned long iova, 545 phys_addr_t paddr, size_t pgsize, size_t pgcount, 546 int prot, gfp_t gfp, size_t *mapped) 547 { 548 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); 549 int ret = -EINVAL; 550 551 if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias) || 552 paddr >= (1ULL << data->iop.cfg.oas))) 553 return -ERANGE; 554 555 /* If no access, then nothing to do */ 556 if (!(prot & (IOMMU_READ | IOMMU_WRITE))) 557 return 0; 558 559 while (pgcount--) { 560 ret = __arm_v7s_map(data, iova, paddr, pgsize, prot, 1, data->pgd, 561 gfp); 562 if (ret) 563 break; 564 565 iova += pgsize; 566 paddr += pgsize; 567 *mapped += pgsize; 568 } 569 /* 570 * Synchronise all PTE updates for the new mapping before there's 571 * a chance for anything to kick off a table walk for the new iova. 572 */ 573 wmb(); 574 575 return ret; 576 } 577 578 static void arm_v7s_free_pgtable(struct io_pgtable *iop) 579 { 580 struct arm_v7s_io_pgtable *data = io_pgtable_to_data(iop); 581 int i; 582 583 for (i = 0; i < ARM_V7S_PTES_PER_LVL(1, &data->iop.cfg); i++) { 584 arm_v7s_iopte pte = data->pgd[i]; 585 586 if (ARM_V7S_PTE_IS_TABLE(pte, 1)) 587 __arm_v7s_free_table(iopte_deref(pte, 1, data), 588 2, data); 589 } 590 __arm_v7s_free_table(data->pgd, 1, data); 591 kmem_cache_destroy(data->l2_tables); 592 kfree(data); 593 } 594 595 static arm_v7s_iopte arm_v7s_split_cont(struct arm_v7s_io_pgtable *data, 596 unsigned long iova, int idx, int lvl, 597 arm_v7s_iopte *ptep) 598 { 599 struct io_pgtable *iop = &data->iop; 600 arm_v7s_iopte pte; 601 size_t size = ARM_V7S_BLOCK_SIZE(lvl); 602 int i; 603 604 /* Check that we didn't lose a race to get the lock */ 605 pte = *ptep; 606 if (!arm_v7s_pte_is_cont(pte, lvl)) 607 return pte; 608 609 ptep -= idx & (ARM_V7S_CONT_PAGES - 1); 610 pte = arm_v7s_cont_to_pte(pte, lvl); 611 for (i = 0; i < ARM_V7S_CONT_PAGES; i++) 612 ptep[i] = pte + i * size; 613 614 __arm_v7s_pte_sync(ptep, ARM_V7S_CONT_PAGES, &iop->cfg); 615 616 size *= ARM_V7S_CONT_PAGES; 617 io_pgtable_tlb_flush_walk(iop, iova, size, size); 618 return pte; 619 } 620 621 static size_t arm_v7s_split_blk_unmap(struct arm_v7s_io_pgtable *data, 622 struct iommu_iotlb_gather *gather, 623 unsigned long iova, size_t size, 624 arm_v7s_iopte blk_pte, 625 arm_v7s_iopte *ptep) 626 { 627 struct io_pgtable_cfg *cfg = &data->iop.cfg; 628 arm_v7s_iopte pte, *tablep; 629 int i, unmap_idx, num_entries, num_ptes; 630 631 tablep = __arm_v7s_alloc_table(2, GFP_ATOMIC, data); 632 if (!tablep) 633 return 0; /* Bytes unmapped */ 634 635 num_ptes = ARM_V7S_PTES_PER_LVL(2, cfg); 636 num_entries = size >> ARM_V7S_LVL_SHIFT(2); 637 unmap_idx = ARM_V7S_LVL_IDX(iova, 2, cfg); 638 639 pte = arm_v7s_prot_to_pte(arm_v7s_pte_to_prot(blk_pte, 1), 2, cfg); 640 if (num_entries > 1) 641 pte = arm_v7s_pte_to_cont(pte, 2); 642 643 for (i = 0; i < num_ptes; i += num_entries, pte += size) { 644 /* Unmap! */ 645 if (i == unmap_idx) 646 continue; 647 648 __arm_v7s_set_pte(&tablep[i], pte, num_entries, cfg); 649 } 650 651 pte = arm_v7s_install_table(tablep, ptep, blk_pte, cfg); 652 if (pte != blk_pte) { 653 __arm_v7s_free_table(tablep, 2, data); 654 655 if (!ARM_V7S_PTE_IS_TABLE(pte, 1)) 656 return 0; 657 658 tablep = iopte_deref(pte, 1, data); 659 return __arm_v7s_unmap(data, gather, iova, size, 2, tablep); 660 } 661 662 io_pgtable_tlb_add_page(&data->iop, gather, iova, size); 663 return size; 664 } 665 666 static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *data, 667 struct iommu_iotlb_gather *gather, 668 unsigned long iova, size_t size, int lvl, 669 arm_v7s_iopte *ptep) 670 { 671 arm_v7s_iopte pte[ARM_V7S_CONT_PAGES]; 672 struct io_pgtable *iop = &data->iop; 673 int idx, i = 0, num_entries = size >> ARM_V7S_LVL_SHIFT(lvl); 674 675 /* Something went horribly wrong and we ran out of page table */ 676 if (WARN_ON(lvl > 2)) 677 return 0; 678 679 idx = ARM_V7S_LVL_IDX(iova, lvl, &iop->cfg); 680 ptep += idx; 681 do { 682 pte[i] = READ_ONCE(ptep[i]); 683 if (WARN_ON(!ARM_V7S_PTE_IS_VALID(pte[i]))) 684 return 0; 685 } while (++i < num_entries); 686 687 /* 688 * If we've hit a contiguous 'large page' entry at this level, it 689 * needs splitting first, unless we're unmapping the whole lot. 690 * 691 * For splitting, we can't rewrite 16 PTEs atomically, and since we 692 * can't necessarily assume TEX remap we don't have a software bit to 693 * mark live entries being split. In practice (i.e. DMA API code), we 694 * will never be splitting large pages anyway, so just wrap this edge 695 * case in a lock for the sake of correctness and be done with it. 696 */ 697 if (num_entries <= 1 && arm_v7s_pte_is_cont(pte[0], lvl)) { 698 unsigned long flags; 699 700 spin_lock_irqsave(&data->split_lock, flags); 701 pte[0] = arm_v7s_split_cont(data, iova, idx, lvl, ptep); 702 spin_unlock_irqrestore(&data->split_lock, flags); 703 } 704 705 /* If the size matches this level, we're in the right place */ 706 if (num_entries) { 707 size_t blk_size = ARM_V7S_BLOCK_SIZE(lvl); 708 709 __arm_v7s_set_pte(ptep, 0, num_entries, &iop->cfg); 710 711 for (i = 0; i < num_entries; i++) { 712 if (ARM_V7S_PTE_IS_TABLE(pte[i], lvl)) { 713 /* Also flush any partial walks */ 714 io_pgtable_tlb_flush_walk(iop, iova, blk_size, 715 ARM_V7S_BLOCK_SIZE(lvl + 1)); 716 ptep = iopte_deref(pte[i], lvl, data); 717 __arm_v7s_free_table(ptep, lvl + 1, data); 718 } else if (!iommu_iotlb_gather_queued(gather)) { 719 io_pgtable_tlb_add_page(iop, gather, iova, blk_size); 720 } 721 iova += blk_size; 722 } 723 return size; 724 } else if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte[0], lvl)) { 725 /* 726 * Insert a table at the next level to map the old region, 727 * minus the part we want to unmap 728 */ 729 return arm_v7s_split_blk_unmap(data, gather, iova, size, pte[0], 730 ptep); 731 } 732 733 /* Keep on walkin' */ 734 ptep = iopte_deref(pte[0], lvl, data); 735 return __arm_v7s_unmap(data, gather, iova, size, lvl + 1, ptep); 736 } 737 738 static size_t arm_v7s_unmap_pages(struct io_pgtable_ops *ops, unsigned long iova, 739 size_t pgsize, size_t pgcount, 740 struct iommu_iotlb_gather *gather) 741 { 742 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); 743 size_t unmapped = 0, ret; 744 745 if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias))) 746 return 0; 747 748 while (pgcount--) { 749 ret = __arm_v7s_unmap(data, gather, iova, pgsize, 1, data->pgd); 750 if (!ret) 751 break; 752 753 unmapped += pgsize; 754 iova += pgsize; 755 } 756 757 return unmapped; 758 } 759 760 static phys_addr_t arm_v7s_iova_to_phys(struct io_pgtable_ops *ops, 761 unsigned long iova) 762 { 763 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops); 764 arm_v7s_iopte *ptep = data->pgd, pte; 765 int lvl = 0; 766 u32 mask; 767 768 do { 769 ptep += ARM_V7S_LVL_IDX(iova, ++lvl, &data->iop.cfg); 770 pte = READ_ONCE(*ptep); 771 ptep = iopte_deref(pte, lvl, data); 772 } while (ARM_V7S_PTE_IS_TABLE(pte, lvl)); 773 774 if (!ARM_V7S_PTE_IS_VALID(pte)) 775 return 0; 776 777 mask = ARM_V7S_LVL_MASK(lvl); 778 if (arm_v7s_pte_is_cont(pte, lvl)) 779 mask *= ARM_V7S_CONT_PAGES; 780 return iopte_to_paddr(pte, lvl, &data->iop.cfg) | (iova & ~mask); 781 } 782 783 static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, 784 void *cookie) 785 { 786 struct arm_v7s_io_pgtable *data; 787 slab_flags_t slab_flag; 788 phys_addr_t paddr; 789 790 if (cfg->ias > (arm_v7s_is_mtk_enabled(cfg) ? 34 : ARM_V7S_ADDR_BITS)) 791 return NULL; 792 793 if (cfg->oas > (arm_v7s_is_mtk_enabled(cfg) ? 35 : ARM_V7S_ADDR_BITS)) 794 return NULL; 795 796 if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | 797 IO_PGTABLE_QUIRK_NO_PERMS | 798 IO_PGTABLE_QUIRK_ARM_MTK_EXT | 799 IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT)) 800 return NULL; 801 802 /* If ARM_MTK_4GB is enabled, the NO_PERMS is also expected. */ 803 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT && 804 !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS)) 805 return NULL; 806 807 if ((cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT) && 808 !arm_v7s_is_mtk_enabled(cfg)) 809 return NULL; 810 811 data = kmalloc(sizeof(*data), GFP_KERNEL); 812 if (!data) 813 return NULL; 814 815 spin_lock_init(&data->split_lock); 816 817 /* 818 * ARM_MTK_TTBR_EXT extend the translation table base support larger 819 * memory address. 820 */ 821 slab_flag = cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT ? 822 0 : ARM_V7S_TABLE_SLAB_FLAGS; 823 824 data->l2_tables = kmem_cache_create("io-pgtable_armv7s_l2", 825 ARM_V7S_TABLE_SIZE(2, cfg), 826 ARM_V7S_TABLE_SIZE(2, cfg), 827 slab_flag, NULL); 828 if (!data->l2_tables) 829 goto out_free_data; 830 831 data->iop.ops = (struct io_pgtable_ops) { 832 .map_pages = arm_v7s_map_pages, 833 .unmap_pages = arm_v7s_unmap_pages, 834 .iova_to_phys = arm_v7s_iova_to_phys, 835 }; 836 837 /* We have to do this early for __arm_v7s_alloc_table to work... */ 838 data->iop.cfg = *cfg; 839 840 /* 841 * Unless the IOMMU driver indicates supersection support by 842 * having SZ_16M set in the initial bitmap, they won't be used. 843 */ 844 cfg->pgsize_bitmap &= SZ_4K | SZ_64K | SZ_1M | SZ_16M; 845 846 /* TCR: T0SZ=0, EAE=0 (if applicable) */ 847 cfg->arm_v7s_cfg.tcr = 0; 848 849 /* 850 * TEX remap: the indices used map to the closest equivalent types 851 * under the non-TEX-remap interpretation of those attribute bits, 852 * excepting various implementation-defined aspects of shareability. 853 */ 854 cfg->arm_v7s_cfg.prrr = ARM_V7S_PRRR_TR(1, ARM_V7S_PRRR_TYPE_DEVICE) | 855 ARM_V7S_PRRR_TR(4, ARM_V7S_PRRR_TYPE_NORMAL) | 856 ARM_V7S_PRRR_TR(7, ARM_V7S_PRRR_TYPE_NORMAL) | 857 ARM_V7S_PRRR_DS0 | ARM_V7S_PRRR_DS1 | 858 ARM_V7S_PRRR_NS1 | ARM_V7S_PRRR_NOS(7); 859 cfg->arm_v7s_cfg.nmrr = ARM_V7S_NMRR_IR(7, ARM_V7S_RGN_WBWA) | 860 ARM_V7S_NMRR_OR(7, ARM_V7S_RGN_WBWA); 861 862 /* Looking good; allocate a pgd */ 863 data->pgd = __arm_v7s_alloc_table(1, GFP_KERNEL, data); 864 if (!data->pgd) 865 goto out_free_data; 866 867 /* Ensure the empty pgd is visible before any actual TTBR write */ 868 wmb(); 869 870 /* TTBR */ 871 paddr = virt_to_phys(data->pgd); 872 if (arm_v7s_is_mtk_enabled(cfg)) 873 cfg->arm_v7s_cfg.ttbr = paddr | upper_32_bits(paddr); 874 else 875 cfg->arm_v7s_cfg.ttbr = paddr | ARM_V7S_TTBR_S | 876 (cfg->coherent_walk ? (ARM_V7S_TTBR_NOS | 877 ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) | 878 ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) : 879 (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) | 880 ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC))); 881 return &data->iop; 882 883 out_free_data: 884 kmem_cache_destroy(data->l2_tables); 885 kfree(data); 886 return NULL; 887 } 888 889 struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = { 890 .alloc = arm_v7s_alloc_pgtable, 891 .free = arm_v7s_free_pgtable, 892 }; 893 894 #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST 895 896 static struct io_pgtable_cfg *cfg_cookie __initdata; 897 898 static void __init dummy_tlb_flush_all(void *cookie) 899 { 900 WARN_ON(cookie != cfg_cookie); 901 } 902 903 static void __init dummy_tlb_flush(unsigned long iova, size_t size, 904 size_t granule, void *cookie) 905 { 906 WARN_ON(cookie != cfg_cookie); 907 WARN_ON(!(size & cfg_cookie->pgsize_bitmap)); 908 } 909 910 static void __init dummy_tlb_add_page(struct iommu_iotlb_gather *gather, 911 unsigned long iova, size_t granule, 912 void *cookie) 913 { 914 dummy_tlb_flush(iova, granule, granule, cookie); 915 } 916 917 static const struct iommu_flush_ops dummy_tlb_ops __initconst = { 918 .tlb_flush_all = dummy_tlb_flush_all, 919 .tlb_flush_walk = dummy_tlb_flush, 920 .tlb_add_page = dummy_tlb_add_page, 921 }; 922 923 #define __FAIL(ops) ({ \ 924 WARN(1, "selftest: test failed\n"); \ 925 selftest_running = false; \ 926 -EFAULT; \ 927 }) 928 929 static int __init arm_v7s_do_selftests(void) 930 { 931 struct io_pgtable_ops *ops; 932 struct io_pgtable_cfg cfg = { 933 .tlb = &dummy_tlb_ops, 934 .oas = 32, 935 .ias = 32, 936 .coherent_walk = true, 937 .quirks = IO_PGTABLE_QUIRK_ARM_NS, 938 .pgsize_bitmap = SZ_4K | SZ_64K | SZ_1M | SZ_16M, 939 }; 940 unsigned int iova, size, iova_start; 941 unsigned int i, loopnr = 0; 942 size_t mapped; 943 944 selftest_running = true; 945 946 cfg_cookie = &cfg; 947 948 ops = alloc_io_pgtable_ops(ARM_V7S, &cfg, &cfg); 949 if (!ops) { 950 pr_err("selftest: failed to allocate io pgtable ops\n"); 951 return -EINVAL; 952 } 953 954 /* 955 * Initial sanity checks. 956 * Empty page tables shouldn't provide any translations. 957 */ 958 if (ops->iova_to_phys(ops, 42)) 959 return __FAIL(ops); 960 961 if (ops->iova_to_phys(ops, SZ_1G + 42)) 962 return __FAIL(ops); 963 964 if (ops->iova_to_phys(ops, SZ_2G + 42)) 965 return __FAIL(ops); 966 967 /* 968 * Distinct mappings of different granule sizes. 969 */ 970 iova = 0; 971 for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) { 972 size = 1UL << i; 973 if (ops->map_pages(ops, iova, iova, size, 1, 974 IOMMU_READ | IOMMU_WRITE | 975 IOMMU_NOEXEC | IOMMU_CACHE, 976 GFP_KERNEL, &mapped)) 977 return __FAIL(ops); 978 979 /* Overlapping mappings */ 980 if (!ops->map_pages(ops, iova, iova + size, size, 1, 981 IOMMU_READ | IOMMU_NOEXEC, GFP_KERNEL, 982 &mapped)) 983 return __FAIL(ops); 984 985 if (ops->iova_to_phys(ops, iova + 42) != (iova + 42)) 986 return __FAIL(ops); 987 988 iova += SZ_16M; 989 loopnr++; 990 } 991 992 /* Partial unmap */ 993 i = 1; 994 size = 1UL << __ffs(cfg.pgsize_bitmap); 995 while (i < loopnr) { 996 iova_start = i * SZ_16M; 997 if (ops->unmap_pages(ops, iova_start + size, size, 1, NULL) != size) 998 return __FAIL(ops); 999 1000 /* Remap of partial unmap */ 1001 if (ops->map_pages(ops, iova_start + size, size, size, 1, 1002 IOMMU_READ, GFP_KERNEL, &mapped)) 1003 return __FAIL(ops); 1004 1005 if (ops->iova_to_phys(ops, iova_start + size + 42) 1006 != (size + 42)) 1007 return __FAIL(ops); 1008 i++; 1009 } 1010 1011 /* Full unmap */ 1012 iova = 0; 1013 for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) { 1014 size = 1UL << i; 1015 1016 if (ops->unmap_pages(ops, iova, size, 1, NULL) != size) 1017 return __FAIL(ops); 1018 1019 if (ops->iova_to_phys(ops, iova + 42)) 1020 return __FAIL(ops); 1021 1022 /* Remap full block */ 1023 if (ops->map_pages(ops, iova, iova, size, 1, IOMMU_WRITE, 1024 GFP_KERNEL, &mapped)) 1025 return __FAIL(ops); 1026 1027 if (ops->iova_to_phys(ops, iova + 42) != (iova + 42)) 1028 return __FAIL(ops); 1029 1030 iova += SZ_16M; 1031 } 1032 1033 free_io_pgtable_ops(ops); 1034 1035 selftest_running = false; 1036 1037 pr_info("self test ok\n"); 1038 return 0; 1039 } 1040 subsys_initcall(arm_v7s_do_selftests); 1041 #endif 1042