1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Generic page table allocator for IOMMUs. 4 * 5 * Copyright (C) 2014 ARM Limited 6 * 7 * Author: Will Deacon <will.deacon@arm.com> 8 */ 9 10 #include <linux/bug.h> 11 #include <linux/io-pgtable.h> 12 #include <linux/kernel.h> 13 #include <linux/types.h> 14 15 static const struct io_pgtable_init_fns * 16 io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = { 17 #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE 18 [ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns, 19 [ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns, 20 [ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns, 21 [ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns, 22 [ARM_MALI_LPAE] = &io_pgtable_arm_mali_lpae_init_fns, 23 #endif 24 #ifdef CONFIG_IOMMU_IO_PGTABLE_DART 25 [APPLE_DART] = &io_pgtable_apple_dart_init_fns, 26 [APPLE_DART2] = &io_pgtable_apple_dart_init_fns, 27 #endif 28 #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S 29 [ARM_V7S] = &io_pgtable_arm_v7s_init_fns, 30 #endif 31 }; 32 33 static int check_custom_allocator(enum io_pgtable_fmt fmt, 34 struct io_pgtable_cfg *cfg) 35 { 36 /* No custom allocator, no need to check the format. */ 37 if (!cfg->alloc && !cfg->free) 38 return 0; 39 40 /* When passing a custom allocator, both the alloc and free 41 * functions should be provided. 42 */ 43 if (!cfg->alloc || !cfg->free) 44 return -EINVAL; 45 46 /* Make sure the format supports custom allocators. */ 47 if (io_pgtable_init_table[fmt]->caps & IO_PGTABLE_CAP_CUSTOM_ALLOCATOR) 48 return 0; 49 50 return -EINVAL; 51 } 52 53 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, 54 struct io_pgtable_cfg *cfg, 55 void *cookie) 56 { 57 struct io_pgtable *iop; 58 const struct io_pgtable_init_fns *fns; 59 60 if (fmt >= IO_PGTABLE_NUM_FMTS) 61 return NULL; 62 63 if (check_custom_allocator(fmt, cfg)) 64 return NULL; 65 66 fns = io_pgtable_init_table[fmt]; 67 if (!fns) 68 return NULL; 69 70 iop = fns->alloc(cfg, cookie); 71 if (!iop) 72 return NULL; 73 74 iop->fmt = fmt; 75 iop->cookie = cookie; 76 iop->cfg = *cfg; 77 78 return &iop->ops; 79 } 80 EXPORT_SYMBOL_GPL(alloc_io_pgtable_ops); 81 82 /* 83 * It is the IOMMU driver's responsibility to ensure that the page table 84 * is no longer accessible to the walker by this point. 85 */ 86 void free_io_pgtable_ops(struct io_pgtable_ops *ops) 87 { 88 struct io_pgtable *iop; 89 90 if (!ops) 91 return; 92 93 iop = io_pgtable_ops_to_pgtable(ops); 94 io_pgtable_tlb_flush_all(iop); 95 io_pgtable_init_table[iop->fmt]->free(iop); 96 } 97 EXPORT_SYMBOL_GPL(free_io_pgtable_ops); 98