|
| 1 | +/* |
| 2 | + * OMAP Crypto driver common support routines. |
| 3 | + * |
| 4 | + * Copyright (c) 2017 Texas Instruments Incorporated |
| 5 | + |
| 6 | + * |
| 7 | + * This program is free software; you can redistribute it and/or modify |
| 8 | + * it under the terms of the GNU General Public License version 2 as published |
| 9 | + * by the Free Software Foundation. |
| 10 | + */ |
| 11 | + |
| 12 | +#include <linux/module.h> |
| 13 | +#include <linux/kernel.h> |
| 14 | +#include <linux/scatterlist.h> |
| 15 | +#include <crypto/scatterwalk.h> |
| 16 | + |
| 17 | +#include "omap-crypto.h" |
| 18 | + |
| 19 | +static int omap_crypto_copy_sg_lists(int total, int bs, |
| 20 | + struct scatterlist **sg, |
| 21 | + struct scatterlist *new_sg, u16 flags) |
| 22 | +{ |
| 23 | + int n = sg_nents(*sg); |
| 24 | + struct scatterlist *tmp; |
| 25 | + |
| 26 | + if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) { |
| 27 | + new_sg = kmalloc_array(n, sizeof(*sg), GFP_KERNEL); |
| 28 | + if (!new_sg) |
| 29 | + return -ENOMEM; |
| 30 | + |
| 31 | + sg_init_table(new_sg, n); |
| 32 | + } |
| 33 | + |
| 34 | + tmp = new_sg; |
| 35 | + |
| 36 | + while (*sg && total) { |
| 37 | + int len = (*sg)->length; |
| 38 | + |
| 39 | + if (total < len) |
| 40 | + len = total; |
| 41 | + |
| 42 | + if (len > 0) { |
| 43 | + total -= len; |
| 44 | + sg_set_page(tmp, sg_page(*sg), len, (*sg)->offset); |
| 45 | + if (total <= 0) |
| 46 | + sg_mark_end(tmp); |
| 47 | + tmp = sg_next(tmp); |
| 48 | + } |
| 49 | + |
| 50 | + *sg = sg_next(*sg); |
| 51 | + } |
| 52 | + |
| 53 | + *sg = new_sg; |
| 54 | + |
| 55 | + return 0; |
| 56 | +} |
| 57 | + |
| 58 | +static int omap_crypto_copy_sgs(int total, int bs, struct scatterlist **sg, |
| 59 | + struct scatterlist *new_sg, u16 flags) |
| 60 | +{ |
| 61 | + void *buf; |
| 62 | + int pages; |
| 63 | + int new_len; |
| 64 | + |
| 65 | + new_len = ALIGN(total, bs); |
| 66 | + pages = get_order(new_len); |
| 67 | + |
| 68 | + buf = (void *)__get_free_pages(GFP_ATOMIC, pages); |
| 69 | + if (!buf) { |
| 70 | + pr_err("%s: Couldn't allocate pages for unaligned cases.\n", |
| 71 | + __func__); |
| 72 | + return -ENOMEM; |
| 73 | + } |
| 74 | + |
| 75 | + if (flags & OMAP_CRYPTO_COPY_DATA) { |
| 76 | + scatterwalk_map_and_copy(buf, *sg, 0, total, 0); |
| 77 | + if (flags & OMAP_CRYPTO_ZERO_BUF) |
| 78 | + memset(buf + total, 0, new_len - total); |
| 79 | + } |
| 80 | + |
| 81 | + if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) |
| 82 | + sg_init_table(new_sg, 1); |
| 83 | + |
| 84 | + sg_set_buf(new_sg, buf, new_len); |
| 85 | + |
| 86 | + *sg = new_sg; |
| 87 | + |
| 88 | + return 0; |
| 89 | +} |
| 90 | + |
| 91 | +static int omap_crypto_check_sg(struct scatterlist *sg, int total, int bs, |
| 92 | + u16 flags) |
| 93 | +{ |
| 94 | + int len = 0; |
| 95 | + int num_sg = 0; |
| 96 | + |
| 97 | + if (!IS_ALIGNED(total, bs)) |
| 98 | + return OMAP_CRYPTO_NOT_ALIGNED; |
| 99 | + |
| 100 | + while (sg) { |
| 101 | + num_sg++; |
| 102 | + |
| 103 | + if (!IS_ALIGNED(sg->offset, 4)) |
| 104 | + return OMAP_CRYPTO_NOT_ALIGNED; |
| 105 | + if (!IS_ALIGNED(sg->length, bs)) |
| 106 | + return OMAP_CRYPTO_NOT_ALIGNED; |
| 107 | + |
| 108 | + len += sg->length; |
| 109 | + sg = sg_next(sg); |
| 110 | + |
| 111 | + if (len >= total) |
| 112 | + break; |
| 113 | + } |
| 114 | + |
| 115 | + if ((flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) && num_sg > 1) |
| 116 | + return OMAP_CRYPTO_NOT_ALIGNED; |
| 117 | + |
| 118 | + if (len != total) |
| 119 | + return OMAP_CRYPTO_BAD_DATA_LENGTH; |
| 120 | + |
| 121 | + return 0; |
| 122 | +} |
| 123 | + |
| 124 | +int omap_crypto_align_sg(struct scatterlist **sg, int total, int bs, |
| 125 | + struct scatterlist *new_sg, u16 flags, |
| 126 | + u8 flags_shift, unsigned long *dd_flags) |
| 127 | +{ |
| 128 | + int ret; |
| 129 | + |
| 130 | + *dd_flags &= ~(OMAP_CRYPTO_COPY_MASK << flags_shift); |
| 131 | + |
| 132 | + if (flags & OMAP_CRYPTO_FORCE_COPY) |
| 133 | + ret = OMAP_CRYPTO_NOT_ALIGNED; |
| 134 | + else |
| 135 | + ret = omap_crypto_check_sg(*sg, total, bs, flags); |
| 136 | + |
| 137 | + if (ret == OMAP_CRYPTO_NOT_ALIGNED) { |
| 138 | + ret = omap_crypto_copy_sgs(total, bs, sg, new_sg, flags); |
| 139 | + if (ret) |
| 140 | + return ret; |
| 141 | + *dd_flags |= OMAP_CRYPTO_DATA_COPIED << flags_shift; |
| 142 | + } else if (ret == OMAP_CRYPTO_BAD_DATA_LENGTH) { |
| 143 | + ret = omap_crypto_copy_sg_lists(total, bs, sg, new_sg, flags); |
| 144 | + if (ret) |
| 145 | + return ret; |
| 146 | + if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) |
| 147 | + *dd_flags |= OMAP_CRYPTO_SG_COPIED << flags_shift; |
| 148 | + } else if (flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) { |
| 149 | + sg_set_buf(new_sg, sg_virt(*sg), (*sg)->length); |
| 150 | + } |
| 151 | + |
| 152 | + return 0; |
| 153 | +} |
| 154 | +EXPORT_SYMBOL_GPL(omap_crypto_align_sg); |
| 155 | + |
| 156 | +void omap_crypto_cleanup(struct scatterlist *sg, struct scatterlist *orig, |
| 157 | + int offset, int len, u8 flags_shift, |
| 158 | + unsigned long flags) |
| 159 | +{ |
| 160 | + void *buf; |
| 161 | + int pages; |
| 162 | + |
| 163 | + flags >>= flags_shift; |
| 164 | + flags &= OMAP_CRYPTO_COPY_MASK; |
| 165 | + |
| 166 | + if (!flags) |
| 167 | + return; |
| 168 | + |
| 169 | + buf = sg_virt(sg); |
| 170 | + pages = get_order(len); |
| 171 | + |
| 172 | + if (orig && (flags & OMAP_CRYPTO_COPY_MASK)) |
| 173 | + scatterwalk_map_and_copy(buf, orig, offset, len, 1); |
| 174 | + |
| 175 | + if (flags & OMAP_CRYPTO_DATA_COPIED) |
| 176 | + free_pages((unsigned long)buf, pages); |
| 177 | + else if (flags & OMAP_CRYPTO_SG_COPIED) |
| 178 | + kfree(sg); |
| 179 | +} |
| 180 | +EXPORT_SYMBOL_GPL(omap_crypto_cleanup); |
| 181 | + |
| 182 | +MODULE_DESCRIPTION("OMAP crypto support library."); |
| 183 | +MODULE_LICENSE("GPL v2"); |
| 184 | +MODULE_AUTHOR( "Tero Kristo <[email protected]>"); |
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