drivers/crypto/amlogic/amlogic-gxl-cipher.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * amlogic-cipher.c - hardware cryptographic offloader for Amlogic GXL SoC
   4  *
   5  * Copyright (C) 2018-2019 Corentin LABBE <clabbe@baylibre.com>
   6  *
   7  * This file add support for AES cipher with 128,192,256 bits keysize in
   8  * CBC and ECB mode.
   9  */
  10
  11 #include <linux/crypto.h>
  12 #include <linux/delay.h>
  13 #include <linux/io.h>
  14 #include <crypto/scatterwalk.h>
  15 #include <linux/scatterlist.h>
  16 #include <linux/dma-mapping.h>
  17 #include <crypto/internal/skcipher.h>
  18 #include "amlogic-gxl.h"
  19
  20 static int get_engine_number(struct meson_dev *mc)
  21 {
  22         return atomic_inc_return(&mc->flow) % MAXFLOW;
  23 }
  24
  25 static bool meson_cipher_need_fallback(struct skcipher_request *areq)
  26 {
  27         struct scatterlist *src_sg = areq->src;
  28         struct scatterlist *dst_sg = areq->dst;
  29
  30         if (areq->cryptlen == 0)
  31                 return true;
  32
  33         if (sg_nents(src_sg) != sg_nents(dst_sg))
  34                 return true;
  35
  36         /* KEY/IV descriptors use 3 desc */
  37         if (sg_nents(src_sg) > MAXDESC - 3 || sg_nents(dst_sg) > MAXDESC - 3)
  38                 return true;
  39
  40         while (src_sg && dst_sg) {
  41                 if ((src_sg->length % 16) != 0)
  42                         return true;
  43                 if ((dst_sg->length % 16) != 0)
  44                         return true;
  45                 if (src_sg->length != dst_sg->length)
  46                         return true;
  47                 if (!IS_ALIGNED(src_sg->offset, sizeof(u32)))
  48                         return true;
  49                 if (!IS_ALIGNED(dst_sg->offset, sizeof(u32)))
  50                         return true;
  51                 src_sg = sg_next(src_sg);
  52                 dst_sg = sg_next(dst_sg);
  53         }
  54
  55         return false;
  56 }
  57
  58 static int meson_cipher_do_fallback(struct skcipher_request *areq)
  59 {
  60         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
  61         struct meson_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
  62         struct meson_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
  63         int err;
  64 #ifdef CONFIG_CRYPTO_DEV_AMLOGIC_GXL_DEBUG
  65         struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
  66         struct meson_alg_template *algt;
  67 #endif
  68         SYNC_SKCIPHER_REQUEST_ON_STACK(req, op->fallback_tfm);
  69
  70 #ifdef CONFIG_CRYPTO_DEV_AMLOGIC_GXL_DEBUG
  71         algt = container_of(alg, struct meson_alg_template, alg.skcipher);
  72         algt->stat_fb++;
  73 #endif
  74         skcipher_request_set_sync_tfm(req, op->fallback_tfm);
  75         skcipher_request_set_callback(req, areq->base.flags, NULL, NULL);
  76         skcipher_request_set_crypt(req, areq->src, areq->dst,
  77                                    areq->cryptlen, areq->iv);
  78         if (rctx->op_dir == MESON_DECRYPT)
  79                 err = crypto_skcipher_decrypt(req);
  80         else
  81                 err = crypto_skcipher_encrypt(req);
  82         skcipher_request_zero(req);
  83         return err;
  84 }
  85
  86 static int meson_cipher(struct skcipher_request *areq)
  87 {
  88         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
  89         struct meson_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
  90         struct meson_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
  91         struct meson_dev *mc = op->mc;
  92         struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
  93         struct meson_alg_template *algt;
  94         int flow = rctx->flow;
  95         unsigned int todo, eat, len;
  96         struct scatterlist *src_sg = areq->src;
  97         struct scatterlist *dst_sg = areq->dst;
  98         struct meson_desc *desc;
  99         int nr_sgs, nr_sgd;
 100         int i, err = 0;
 101         unsigned int keyivlen, ivsize, offset, tloffset;
 102         dma_addr_t phykeyiv;
 103         void *backup_iv = NULL, *bkeyiv;
 104         __le32 v;
 105
 106         algt = container_of(alg, struct meson_alg_template, alg.skcipher);
 107
 108         dev_dbg(mc->dev, "%s %s %u %x IV(%u) key=%u flow=%d\n", __func__,
 109                 crypto_tfm_alg_name(areq->base.tfm),
 110                 areq->cryptlen,
 111                 rctx->op_dir, crypto_skcipher_ivsize(tfm),
 112                 op->keylen, flow);
 113
 114 #ifdef CONFIG_CRYPTO_DEV_AMLOGIC_GXL_DEBUG
 115         algt->stat_req++;
 116         mc->chanlist[flow].stat_req++;
 117 #endif
 118
 119         /*
 120          * The hardware expect a list of meson_desc structures.
 121          * The 2 first structures store key
 122          * The third stores IV
 123          */
 124         bkeyiv = kzalloc(48, GFP_KERNEL | GFP_DMA);
 125         if (!bkeyiv)
 126                 return -ENOMEM;
 127
 128         memcpy(bkeyiv, op->key, op->keylen);
 129         keyivlen = op->keylen;
 130
 131         ivsize = crypto_skcipher_ivsize(tfm);
 132         if (areq->iv && ivsize > 0) {
 133                 if (ivsize > areq->cryptlen) {
 134                         dev_err(mc->dev, "invalid ivsize=%d vs len=%d\n", ivsize, areq->cryptlen);
 135                         err = -EINVAL;
 136                         goto theend;
 137                 }
 138                 memcpy(bkeyiv + 32, areq->iv, ivsize);
 139                 keyivlen = 48;
 140                 if (rctx->op_dir == MESON_DECRYPT) {
 141                         backup_iv = kzalloc(ivsize, GFP_KERNEL);
 142                         if (!backup_iv) {
 143                                 err = -ENOMEM;
 144                                 goto theend;
 145                         }
 146                         offset = areq->cryptlen - ivsize;
 147                         scatterwalk_map_and_copy(backup_iv, areq->src, offset,
 148                                                  ivsize, 0);
 149                 }
 150         }
 151         if (keyivlen == 24)
 152                 keyivlen = 32;
 153
 154         phykeyiv = dma_map_single(mc->dev, bkeyiv, keyivlen,
 155                                   DMA_TO_DEVICE);
 156         err = dma_mapping_error(mc->dev, phykeyiv);
 157         if (err) {
 158                 dev_err(mc->dev, "Cannot DMA MAP KEY IV\n");
 159                 goto theend;
 160         }
 161
 162         tloffset = 0;
 163         eat = 0;
 164         i = 0;
 165         while (keyivlen > eat) {
 166                 desc = &mc->chanlist[flow].tl[tloffset];
 167                 memset(desc, 0, sizeof(struct meson_desc));
 168                 todo = min(keyivlen - eat, 16u);
 169                 desc->t_src = cpu_to_le32(phykeyiv + i * 16);
 170                 desc->t_dst = cpu_to_le32(i * 16);
 171                 v = (MODE_KEY << 20) | DESC_OWN | 16;
 172                 desc->t_status = cpu_to_le32(v);
 173
 174                 eat += todo;
 175                 i++;
 176                 tloffset++;
 177         }
 178
 179         if (areq->src == areq->dst) {
 180                 nr_sgs = dma_map_sg(mc->dev, areq->src, sg_nents(areq->src),
 181                                     DMA_BIDIRECTIONAL);
 182                 if (nr_sgs < 0) {
 183                         dev_err(mc->dev, "Invalid SG count %d\n", nr_sgs);
 184                         err = -EINVAL;
 185                         goto theend;
 186                 }
 187                 nr_sgd = nr_sgs;
 188         } else {
 189                 nr_sgs = dma_map_sg(mc->dev, areq->src, sg_nents(areq->src),
 190                                     DMA_TO_DEVICE);
 191                 if (nr_sgs < 0 || nr_sgs > MAXDESC - 3) {
 192                         dev_err(mc->dev, "Invalid SG count %d\n", nr_sgs);
 193                         err = -EINVAL;
 194                         goto theend;
 195                 }
 196                 nr_sgd = dma_map_sg(mc->dev, areq->dst, sg_nents(areq->dst),
 197                                     DMA_FROM_DEVICE);
 198                 if (nr_sgd < 0 || nr_sgd > MAXDESC - 3) {
 199                         dev_err(mc->dev, "Invalid SG count %d\n", nr_sgd);
 200                         err = -EINVAL;
 201                         goto theend;
 202                 }
 203         }
 204
 205         src_sg = areq->src;
 206         dst_sg = areq->dst;
 207         len = areq->cryptlen;
 208         while (src_sg) {
 209                 desc = &mc->chanlist[flow].tl[tloffset];
 210                 memset(desc, 0, sizeof(struct meson_desc));
 211
 212                 desc->t_src = cpu_to_le32(sg_dma_address(src_sg));
 213                 desc->t_dst = cpu_to_le32(sg_dma_address(dst_sg));
 214                 todo = min(len, sg_dma_len(src_sg));
 215                 v = (op->keymode << 20) | DESC_OWN | todo | (algt->blockmode << 26);
 216                 if (rctx->op_dir)
 217                         v |= DESC_ENCRYPTION;
 218                 len -= todo;
 219
 220                 if (!sg_next(src_sg))
 221                         v |= DESC_LAST;
 222                 desc->t_status = cpu_to_le32(v);
 223                 tloffset++;
 224                 src_sg = sg_next(src_sg);
 225                 dst_sg = sg_next(dst_sg);
 226         }
 227
 228         reinit_completion(&mc->chanlist[flow].complete);
 229         mc->chanlist[flow].status = 0;
 230         writel(mc->chanlist[flow].t_phy | 2, mc->base + (flow << 2));
 231         wait_for_completion_interruptible_timeout(&mc->chanlist[flow].complete,
 232                                                   msecs_to_jiffies(500));
 233         if (mc->chanlist[flow].status == 0) {
 234                 dev_err(mc->dev, "DMA timeout for flow %d\n", flow);
 235                 err = -EINVAL;
 236         }
 237
 238         dma_unmap_single(mc->dev, phykeyiv, keyivlen, DMA_TO_DEVICE);
 239
 240         if (areq->src == areq->dst) {
 241                 dma_unmap_sg(mc->dev, areq->src, nr_sgs, DMA_BIDIRECTIONAL);
 242         } else {
 243                 dma_unmap_sg(mc->dev, areq->src, nr_sgs, DMA_TO_DEVICE);
 244                 dma_unmap_sg(mc->dev, areq->dst, nr_sgd, DMA_FROM_DEVICE);
 245         }
 246
 247         if (areq->iv && ivsize > 0) {
 248                 if (rctx->op_dir == MESON_DECRYPT) {
 249                         memcpy(areq->iv, backup_iv, ivsize);
 250                 } else {
 251                         scatterwalk_map_and_copy(areq->iv, areq->dst,
 252                                                  areq->cryptlen - ivsize,
 253                                                  ivsize, 0);
 254                 }
 255         }
 256 theend:
 257         kzfree(bkeyiv);
 258         kzfree(backup_iv);
 259
 260         return err;
 261 }
 262
 263 static int meson_handle_cipher_request(struct crypto_engine *engine,
 264                                        void *areq)
 265 {
 266         int err;
 267         struct skcipher_request *breq = container_of(areq, struct skcipher_request, base);
 268
 269         err = meson_cipher(breq);
 270         crypto_finalize_skcipher_request(engine, breq, err);
 271
 272         return 0;
 273 }
 274
 275 int meson_skdecrypt(struct skcipher_request *areq)
 276 {
 277         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 278         struct meson_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 279         struct meson_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
 280         struct crypto_engine *engine;
 281         int e;
 282
 283         rctx->op_dir = MESON_DECRYPT;
 284         if (meson_cipher_need_fallback(areq))
 285                 return meson_cipher_do_fallback(areq);
 286         e = get_engine_number(op->mc);
 287         engine = op->mc->chanlist[e].engine;
 288         rctx->flow = e;
 289
 290         return crypto_transfer_skcipher_request_to_engine(engine, areq);
 291 }
 292
 293 int meson_skencrypt(struct skcipher_request *areq)
 294 {
 295         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 296         struct meson_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 297         struct meson_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
 298         struct crypto_engine *engine;
 299         int e;
 300
 301         rctx->op_dir = MESON_ENCRYPT;
 302         if (meson_cipher_need_fallback(areq))
 303                 return meson_cipher_do_fallback(areq);
 304         e = get_engine_number(op->mc);
 305         engine = op->mc->chanlist[e].engine;
 306         rctx->flow = e;
 307
 308         return crypto_transfer_skcipher_request_to_engine(engine, areq);
 309 }
 310
 311 int meson_cipher_init(struct crypto_tfm *tfm)
 312 {
 313         struct meson_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
 314         struct meson_alg_template *algt;
 315         const char *name = crypto_tfm_alg_name(tfm);
 316         struct crypto_skcipher *sktfm = __crypto_skcipher_cast(tfm);
 317         struct skcipher_alg *alg = crypto_skcipher_alg(sktfm);
 318
 319         memset(op, 0, sizeof(struct meson_cipher_tfm_ctx));
 320
 321         algt = container_of(alg, struct meson_alg_template, alg.skcipher);
 322         op->mc = algt->mc;
 323
 324         sktfm->reqsize = sizeof(struct meson_cipher_req_ctx);
 325
 326         op->fallback_tfm = crypto_alloc_sync_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
 327         if (IS_ERR(op->fallback_tfm)) {
 328                 dev_err(op->mc->dev, "ERROR: Cannot allocate fallback for %s %ld\n",
 329                         name, PTR_ERR(op->fallback_tfm));
 330                 return PTR_ERR(op->fallback_tfm);
 331         }
 332
 333         op->enginectx.op.do_one_request = meson_handle_cipher_request;
 334         op->enginectx.op.prepare_request = NULL;
 335         op->enginectx.op.unprepare_request = NULL;
 336
 337         return 0;
 338 }
 339
 340 void meson_cipher_exit(struct crypto_tfm *tfm)
 341 {
 342         struct meson_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
 343
 344         if (op->key) {
 345                 memzero_explicit(op->key, op->keylen);
 346                 kfree(op->key);
 347         }
 348         crypto_free_sync_skcipher(op->fallback_tfm);
 349 }
 350
 351 int meson_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 352                      unsigned int keylen)
 353 {
 354         struct meson_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 355         struct meson_dev *mc = op->mc;
 356
 357         switch (keylen) {
 358         case 128 / 8:
 359                 op->keymode = MODE_AES_128;
 360                 break;
 361         case 192 / 8:
 362                 op->keymode = MODE_AES_192;
 363                 break;
 364         case 256 / 8:
 365                 op->keymode = MODE_AES_256;
 366                 break;
 367         default:
 368                 dev_dbg(mc->dev, "ERROR: Invalid keylen %u\n", keylen);
 369                 return -EINVAL;
 370         }
 371         if (op->key) {
 372                 memzero_explicit(op->key, op->keylen);
 373                 kfree(op->key);
 374         }
 375         op->keylen = keylen;
 376         op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
 377         if (!op->key)
 378                 return -ENOMEM;
 379
 380         return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen);
 381 }