drivers/crypto/allwinner/sun8i-ce/sun8i-ce-prng.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * sun8i-ce-prng.c - hardware cryptographic offloader for
   4  * Allwinner H3/A64/H5/H2+/H6/R40 SoC
   5  *
   6  * Copyright (C) 2015-2020 Corentin Labbe <clabbe@baylibre.com>
   7  *
   8  * This file handle the PRNG
   9  *
  10  * You could find a link for the datasheet in Documentation/arm/sunxi.rst
  11  */
  12 #include "sun8i-ce.h"
  13 #include <linux/dma-mapping.h>
  14 #include <linux/pm_runtime.h>
  15 #include <crypto/internal/rng.h>
  16
  17 int sun8i_ce_prng_init(struct crypto_tfm *tfm)
  18 {
  19         struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
  20
  21         memset(ctx, 0, sizeof(struct sun8i_ce_rng_tfm_ctx));
  22         return 0;
  23 }
  24
  25 void sun8i_ce_prng_exit(struct crypto_tfm *tfm)
  26 {
  27         struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
  28
  29         memzero_explicit(ctx->seed, ctx->slen);
  30         kfree(ctx->seed);
  31         ctx->seed = NULL;
  32         ctx->slen = 0;
  33 }
  34
  35 int sun8i_ce_prng_seed(struct crypto_rng *tfm, const u8 *seed,
  36                        unsigned int slen)
  37 {
  38         struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
  39
  40         if (ctx->seed && ctx->slen != slen) {
  41                 memzero_explicit(ctx->seed, ctx->slen);
  42                 kfree(ctx->seed);
  43                 ctx->slen = 0;
  44                 ctx->seed = NULL;
  45         }
  46         if (!ctx->seed)
  47                 ctx->seed = kmalloc(slen, GFP_KERNEL | GFP_DMA);
  48         if (!ctx->seed)
  49                 return -ENOMEM;
  50
  51         memcpy(ctx->seed, seed, slen);
  52         ctx->slen = slen;
  53
  54         return 0;
  55 }
  56
  57 int sun8i_ce_prng_generate(struct crypto_rng *tfm, const u8 *src,
  58                            unsigned int slen, u8 *dst, unsigned int dlen)
  59 {
  60         struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
  61         struct rng_alg *alg = crypto_rng_alg(tfm);
  62         struct sun8i_ce_alg_template *algt;
  63         struct sun8i_ce_dev *ce;
  64         dma_addr_t dma_iv, dma_dst;
  65         int err = 0;
  66         int flow = 3;
  67         unsigned int todo;
  68         struct sun8i_ce_flow *chan;
  69         struct ce_task *cet;
  70         u32 common, sym;
  71         void *d;
  72
  73         algt = container_of(alg, struct sun8i_ce_alg_template, alg.rng);
  74         ce = algt->ce;
  75
  76         if (ctx->slen == 0) {
  77                 dev_err(ce->dev, "not seeded\n");
  78                 return -EINVAL;
  79         }
  80
  81         /* we want dlen + seedsize rounded up to a multiple of PRNG_DATA_SIZE */
  82         todo = dlen + ctx->slen + PRNG_DATA_SIZE * 2;
  83         todo -= todo % PRNG_DATA_SIZE;
  84
  85         d = kzalloc(todo, GFP_KERNEL | GFP_DMA);
  86         if (!d) {
  87                 err = -ENOMEM;
  88                 goto err_mem;
  89         }
  90
  91         dev_dbg(ce->dev, "%s PRNG slen=%u dlen=%u todo=%u multi=%u\n", __func__,
  92                 slen, dlen, todo, todo / PRNG_DATA_SIZE);
  93
  94 #ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG
  95         algt->stat_req++;
  96         algt->stat_bytes += todo;
  97 #endif
  98
  99         dma_iv = dma_map_single(ce->dev, ctx->seed, ctx->slen, DMA_TO_DEVICE);
 100         if (dma_mapping_error(ce->dev, dma_iv)) {
 101                 dev_err(ce->dev, "Cannot DMA MAP IV\n");
 102                 goto err_iv;
 103         }
 104
 105         dma_dst = dma_map_single(ce->dev, d, todo, DMA_FROM_DEVICE);
 106         if (dma_mapping_error(ce->dev, dma_dst)) {
 107                 dev_err(ce->dev, "Cannot DMA MAP DST\n");
 108                 err = -EFAULT;
 109                 goto err_dst;
 110         }
 111
 112         err = pm_runtime_get_sync(ce->dev);
 113         if (err < 0) {
 114                 pm_runtime_put_noidle(ce->dev);
 115                 goto err_pm;
 116         }
 117
 118         mutex_lock(&ce->rnglock);
 119         chan = &ce->chanlist[flow];
 120
 121         cet = &chan->tl[0];
 122         memset(cet, 0, sizeof(struct ce_task));
 123
 124         cet->t_id = cpu_to_le32(flow);
 125         common = ce->variant->prng | CE_COMM_INT;
 126         cet->t_common_ctl = cpu_to_le32(common);
 127
 128         /* recent CE (H6) need length in bytes, in word otherwise */
 129         if (ce->variant->prng_t_dlen_in_bytes)
 130                 cet->t_dlen = cpu_to_le32(todo);
 131         else
 132                 cet->t_dlen = cpu_to_le32(todo / 4);
 133
 134         sym = PRNG_LD;
 135         cet->t_sym_ctl = cpu_to_le32(sym);
 136         cet->t_asym_ctl = 0;
 137
 138         cet->t_key = cpu_to_le32(dma_iv);
 139         cet->t_iv = cpu_to_le32(dma_iv);
 140
 141         cet->t_dst[0].addr = cpu_to_le32(dma_dst);
 142         cet->t_dst[0].len = cpu_to_le32(todo / 4);
 143         ce->chanlist[flow].timeout = 2000;
 144
 145         err = sun8i_ce_run_task(ce, 3, "PRNG");
 146         mutex_unlock(&ce->rnglock);
 147
 148         pm_runtime_put(ce->dev);
 149
 150 err_pm:
 151         dma_unmap_single(ce->dev, dma_dst, todo, DMA_FROM_DEVICE);
 152 err_dst:
 153         dma_unmap_single(ce->dev, dma_iv, ctx->slen, DMA_TO_DEVICE);
 154
 155         if (!err) {
 156                 memcpy(dst, d, dlen);
 157                 memcpy(ctx->seed, d + dlen, ctx->slen);
 158         }
 159         memzero_explicit(d, todo);
 160 err_iv:
 161         kfree(d);
 162 err_mem:
 163         return err;
 164 }