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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * OMAP Crypto driver common support routines.4 *5 * Copyright (c) 2017 Texas Instruments Incorporated6 * Tero Kristo <t-kristo@ti.com>7 */8 9#include <linux/module.h>10#include <linux/kernel.h>11#include <linux/scatterlist.h>12#include <crypto/scatterwalk.h>13 14#include "omap-crypto.h"15 16static int omap_crypto_copy_sg_lists(int total, int bs,17 struct scatterlist **sg,18 struct scatterlist *new_sg, u16 flags)19{20 int n = sg_nents(*sg);21 struct scatterlist *tmp;22 23 if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY)) {24 new_sg = kmalloc_array(n, sizeof(*sg), GFP_KERNEL);25 if (!new_sg)26 return -ENOMEM;27 28 sg_init_table(new_sg, n);29 }30 31 tmp = new_sg;32 33 while (*sg && total) {34 int len = (*sg)->length;35 36 if (total < len)37 len = total;38 39 if (len > 0) {40 total -= len;41 sg_set_page(tmp, sg_page(*sg), len, (*sg)->offset);42 if (total <= 0)43 sg_mark_end(tmp);44 tmp = sg_next(tmp);45 }46 47 *sg = sg_next(*sg);48 }49 50 *sg = new_sg;51 52 return 0;53}54 55static int omap_crypto_copy_sgs(int total, int bs, struct scatterlist **sg,56 struct scatterlist *new_sg, u16 flags)57{58 void *buf;59 int pages;60 int new_len;61 62 new_len = ALIGN(total, bs);63 pages = get_order(new_len);64 65 buf = (void *)__get_free_pages(GFP_ATOMIC, pages);66 if (!buf) {67 pr_err("%s: Couldn't allocate pages for unaligned cases.\n",68 __func__);69 return -ENOMEM;70 }71 72 if (flags & OMAP_CRYPTO_COPY_DATA) {73 scatterwalk_map_and_copy(buf, *sg, 0, total, 0);74 if (flags & OMAP_CRYPTO_ZERO_BUF)75 memset(buf + total, 0, new_len - total);76 }77 78 if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))79 sg_init_table(new_sg, 1);80 81 sg_set_buf(new_sg, buf, new_len);82 83 *sg = new_sg;84 85 return 0;86}87 88static int omap_crypto_check_sg(struct scatterlist *sg, int total, int bs,89 u16 flags)90{91 int len = 0;92 int num_sg = 0;93 94 if (!IS_ALIGNED(total, bs))95 return OMAP_CRYPTO_NOT_ALIGNED;96 97 while (sg) {98 num_sg++;99 100 if (!IS_ALIGNED(sg->offset, 4))101 return OMAP_CRYPTO_NOT_ALIGNED;102 if (!IS_ALIGNED(sg->length, bs))103 return OMAP_CRYPTO_NOT_ALIGNED;104#ifdef CONFIG_ZONE_DMA105 if (page_zonenum(sg_page(sg)) != ZONE_DMA)106 return OMAP_CRYPTO_NOT_ALIGNED;107#endif108 109 len += sg->length;110 sg = sg_next(sg);111 112 if (len >= total)113 break;114 }115 116 if ((flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) && num_sg > 1)117 return OMAP_CRYPTO_NOT_ALIGNED;118 119 if (len != total)120 return OMAP_CRYPTO_BAD_DATA_LENGTH;121 122 return 0;123}124 125int omap_crypto_align_sg(struct scatterlist **sg, int total, int bs,126 struct scatterlist *new_sg, u16 flags,127 u8 flags_shift, unsigned long *dd_flags)128{129 int ret;130 131 *dd_flags &= ~(OMAP_CRYPTO_COPY_MASK << flags_shift);132 133 if (flags & OMAP_CRYPTO_FORCE_COPY)134 ret = OMAP_CRYPTO_NOT_ALIGNED;135 else136 ret = omap_crypto_check_sg(*sg, total, bs, flags);137 138 if (ret == OMAP_CRYPTO_NOT_ALIGNED) {139 ret = omap_crypto_copy_sgs(total, bs, sg, new_sg, flags);140 if (ret)141 return ret;142 *dd_flags |= OMAP_CRYPTO_DATA_COPIED << flags_shift;143 } else if (ret == OMAP_CRYPTO_BAD_DATA_LENGTH) {144 ret = omap_crypto_copy_sg_lists(total, bs, sg, new_sg, flags);145 if (ret)146 return ret;147 if (!(flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY))148 *dd_flags |= OMAP_CRYPTO_SG_COPIED << flags_shift;149 } else if (flags & OMAP_CRYPTO_FORCE_SINGLE_ENTRY) {150 sg_set_buf(new_sg, sg_virt(*sg), (*sg)->length);151 }152 153 return 0;154}155EXPORT_SYMBOL_GPL(omap_crypto_align_sg);156 157static void omap_crypto_copy_data(struct scatterlist *src,158 struct scatterlist *dst,159 int offset, int len)160{161 int amt;162 void *srcb, *dstb;163 int srco = 0, dsto = offset;164 165 while (src && dst && len) {166 if (srco >= src->length) {167 srco -= src->length;168 src = sg_next(src);169 continue;170 }171 172 if (dsto >= dst->length) {173 dsto -= dst->length;174 dst = sg_next(dst);175 continue;176 }177 178 amt = min(src->length - srco, dst->length - dsto);179 amt = min(len, amt);180 181 srcb = kmap_atomic(sg_page(src)) + srco + src->offset;182 dstb = kmap_atomic(sg_page(dst)) + dsto + dst->offset;183 184 memcpy(dstb, srcb, amt);185 186 flush_dcache_page(sg_page(dst));187 188 kunmap_atomic(srcb);189 kunmap_atomic(dstb);190 191 srco += amt;192 dsto += amt;193 len -= amt;194 }195}196 197void omap_crypto_cleanup(struct scatterlist *sg, struct scatterlist *orig,198 int offset, int len, u8 flags_shift,199 unsigned long flags)200{201 void *buf;202 int pages;203 204 flags >>= flags_shift;205 flags &= OMAP_CRYPTO_COPY_MASK;206 207 if (!flags)208 return;209 210 buf = sg_virt(sg);211 pages = get_order(len);212 213 if (orig && (flags & OMAP_CRYPTO_DATA_COPIED))214 omap_crypto_copy_data(sg, orig, offset, len);215 216 if (flags & OMAP_CRYPTO_DATA_COPIED)217 free_pages((unsigned long)buf, pages);218 else if (flags & OMAP_CRYPTO_SG_COPIED)219 kfree(sg);220}221EXPORT_SYMBOL_GPL(omap_crypto_cleanup);222 223MODULE_DESCRIPTION("OMAP crypto support library.");224MODULE_LICENSE("GPL v2");225MODULE_AUTHOR("Tero Kristo <t-kristo@ti.com>");226