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 #ifdef CONFIG_AMD_IOMMU 32 [AMD_IOMMU_V1] = &io_pgtable_amd_iommu_v1_init_fns, 33 [AMD_IOMMU_V2] = &io_pgtable_amd_iommu_v2_init_fns, 34 #endif 35 }; 36 37 static int check_custom_allocator(enum io_pgtable_fmt fmt, 38 struct io_pgtable_cfg *cfg) 39 { 40 /* No custom allocator, no need to check the format. */ 41 if (!cfg->alloc && !cfg->free) 42 return 0; 43 44 /* When passing a custom allocator, both the alloc and free 45 * functions should be provided. 46 */ 47 if (!cfg->alloc || !cfg->free) 48 return -EINVAL; 49 50 /* Make sure the format supports custom allocators. */ 51 if (io_pgtable_init_table[fmt]->caps & IO_PGTABLE_CAP_CUSTOM_ALLOCATOR) 52 return 0; 53 54 return -EINVAL; 55 } 56 57 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, 58 struct io_pgtable_cfg *cfg, 59 void *cookie) 60 { 61 struct io_pgtable *iop; 62 const struct io_pgtable_init_fns *fns; 63 64 if (fmt >= IO_PGTABLE_NUM_FMTS) 65 return NULL; 66 67 if (check_custom_allocator(fmt, cfg)) 68 return NULL; 69 70 fns = io_pgtable_init_table[fmt]; 71 if (!fns) 72 return NULL; 73 74 iop = fns->alloc(cfg, cookie); 75 if (!iop) 76 return NULL; 77 78 iop->fmt = fmt; 79 iop->cookie = cookie; 80 iop->cfg = *cfg; 81 82 return &iop->ops; 83 } 84 EXPORT_SYMBOL_GPL(alloc_io_pgtable_ops); 85 86 /* 87 * It is the IOMMU driver's responsibility to ensure that the page table 88 * is no longer accessible to the walker by this point. 89 */ 90 void free_io_pgtable_ops(struct io_pgtable_ops *ops) 91 { 92 struct io_pgtable *iop; 93 94 if (!ops) 95 return; 96 97 iop = io_pgtable_ops_to_pgtable(ops); 98 io_pgtable_tlb_flush_all(iop); 99 io_pgtable_init_table[iop->fmt]->free(iop); 100 } 101 EXPORT_SYMBOL_GPL(free_io_pgtable_ops); 102