drivers/crypto/caam/blob_gen.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
   4  * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
   5  */
   6
   7 #define pr_fmt(fmt) "caam blob_gen: " fmt
   8
   9 #include <linux/bitfield.h>
  10 #include <linux/device.h>
  11 #include <soc/fsl/caam-blob.h>
  12
  13 #include "compat.h"
  14 #include "desc_constr.h"
  15 #include "desc.h"
  16 #include "error.h"
  17 #include "intern.h"
  18 #include "jr.h"
  19 #include "regs.h"
  20
  21 #define CAAM_BLOB_DESC_BYTES_MAX                                        \
  22         /* Command to initialize & stating length of descriptor */      \
  23         (CAAM_CMD_SZ +                                                  \
  24         /* Command to append the key-modifier + key-modifier data */    \
  25          CAAM_CMD_SZ + CAAM_BLOB_KEYMOD_LENGTH +                        \
  26         /* Command to include input key + pointer to the input key */   \
  27          CAAM_CMD_SZ + CAAM_PTR_SZ_MAX +                                \
  28         /* Command to include output key + pointer to the output key */ \
  29          CAAM_CMD_SZ + CAAM_PTR_SZ_MAX +                                \
  30         /* Command describing the operation to perform */               \
  31          CAAM_CMD_SZ)
  32
  33 struct caam_blob_priv {
  34         struct device jrdev;
  35 };
  36
  37 struct caam_blob_job_result {
  38         int err;
  39         struct completion completion;
  40 };
  41
  42 static void caam_blob_job_done(struct device *dev, u32 *desc, u32 err, void *context)
  43 {
  44         struct caam_blob_job_result *res = context;
  45         int ecode = 0;
  46
  47         dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
  48
  49         if (err)
  50                 ecode = caam_jr_strstatus(dev, err);
  51
  52         res->err = ecode;
  53
  54         /*
  55          * Upon completion, desc points to a buffer containing a CAAM job
  56          * descriptor which encapsulates data into an externally-storable
  57          * blob.
  58          */
  59         complete(&res->completion);
  60 }
  61
  62 int caam_process_blob(struct caam_blob_priv *priv,
  63                       struct caam_blob_info *info, bool encap)
  64 {
  65         const struct caam_drv_private *ctrlpriv;
  66         struct caam_blob_job_result testres;
  67         struct device *jrdev = &priv->jrdev;
  68         dma_addr_t dma_in, dma_out;
  69         int op = OP_PCLID_BLOB;
  70         size_t output_len;
  71         u32 *desc;
  72         u32 moo;
  73         int ret;
  74
  75         if (info->key_mod_len > CAAM_BLOB_KEYMOD_LENGTH)
  76                 return -EINVAL;
  77
  78         if (encap) {
  79                 op |= OP_TYPE_ENCAP_PROTOCOL;
  80                 output_len = info->input_len + CAAM_BLOB_OVERHEAD;
  81         } else {
  82                 op |= OP_TYPE_DECAP_PROTOCOL;
  83                 output_len = info->input_len - CAAM_BLOB_OVERHEAD;
  84         }
  85
  86         desc = kzalloc(CAAM_BLOB_DESC_BYTES_MAX, GFP_KERNEL);
  87         if (!desc)
  88                 return -ENOMEM;
  89
  90         dma_in = dma_map_single(jrdev, info->input, info->input_len,
  91                                 DMA_TO_DEVICE);
  92         if (dma_mapping_error(jrdev, dma_in)) {
  93                 dev_err(jrdev, "unable to map input DMA buffer\n");
  94                 ret = -ENOMEM;
  95                 goto out_free;
  96         }
  97
  98         dma_out = dma_map_single(jrdev, info->output, output_len,
  99                                  DMA_FROM_DEVICE);
 100         if (dma_mapping_error(jrdev, dma_out)) {
 101                 dev_err(jrdev, "unable to map output DMA buffer\n");
 102                 ret = -ENOMEM;
 103                 goto out_unmap_in;
 104         }
 105
 106         ctrlpriv = dev_get_drvdata(jrdev->parent);
 107         moo = FIELD_GET(CSTA_MOO, rd_reg32(&ctrlpriv->ctrl->perfmon.status));
 108         if (moo != CSTA_MOO_SECURE && moo != CSTA_MOO_TRUSTED)
 109                 dev_warn(jrdev,
 110                          "using insecure test key, enable HAB to use unique device key!\n");
 111
 112         /*
 113          * A data blob is encrypted using a blob key (BK); a random number.
 114          * The BK is used as an AES-CCM key. The initial block (B0) and the
 115          * initial counter (Ctr0) are generated automatically and stored in
 116          * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
 117          * Class 1 Key Register. Operation Mode is set to AES-CCM.
 118          */
 119
 120         init_job_desc(desc, 0);
 121         append_key_as_imm(desc, info->key_mod, info->key_mod_len,
 122                           info->key_mod_len, CLASS_2 | KEY_DEST_CLASS_REG);
 123         append_seq_in_ptr_intlen(desc, dma_in, info->input_len, 0);
 124         append_seq_out_ptr_intlen(desc, dma_out, output_len, 0);
 125         append_operation(desc, op);
 126
 127         print_hex_dump_debug("data@"__stringify(__LINE__)": ",
 128                              DUMP_PREFIX_ADDRESS, 16, 1, info->input,
 129                              info->input_len, false);
 130         print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
 131                              DUMP_PREFIX_ADDRESS, 16, 1, desc,
 132                              desc_bytes(desc), false);
 133
 134         testres.err = 0;
 135         init_completion(&testres.completion);
 136
 137         ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
 138         if (ret == -EINPROGRESS) {
 139                 wait_for_completion(&testres.completion);
 140                 ret = testres.err;
 141                 print_hex_dump_debug("output@"__stringify(__LINE__)": ",
 142                                      DUMP_PREFIX_ADDRESS, 16, 1, info->output,
 143                                      output_len, false);
 144         }
 145
 146         if (ret == 0)
 147                 info->output_len = output_len;
 148
 149         dma_unmap_single(jrdev, dma_out, output_len, DMA_FROM_DEVICE);
 150 out_unmap_in:
 151         dma_unmap_single(jrdev, dma_in, info->input_len, DMA_TO_DEVICE);
 152 out_free:
 153         kfree(desc);
 154
 155         return ret;
 156 }
 157 EXPORT_SYMBOL(caam_process_blob);
 158
 159 struct caam_blob_priv *caam_blob_gen_init(void)
 160 {
 161         struct caam_drv_private *ctrlpriv;
 162         struct device *jrdev;
 163
 164         /*
 165          * caam_blob_gen_init() may expectedly fail with -ENODEV, e.g. when
 166          * CAAM driver didn't probe or when SoC lacks BLOB support. An
 167          * error would be harsh in this case, so we stick to info level.
 168          */
 169
 170         jrdev = caam_jr_alloc();
 171         if (IS_ERR(jrdev)) {
 172                 pr_info("job ring requested, but none currently available\n");
 173                 return ERR_PTR(-ENODEV);
 174         }
 175
 176         ctrlpriv = dev_get_drvdata(jrdev->parent);
 177         if (!ctrlpriv->blob_present) {
 178                 dev_info(jrdev, "no hardware blob generation support\n");
 179                 caam_jr_free(jrdev);
 180                 return ERR_PTR(-ENODEV);
 181         }
 182
 183         return container_of(jrdev, struct caam_blob_priv, jrdev);
 184 }
 185 EXPORT_SYMBOL(caam_blob_gen_init);
 186
 187 void caam_blob_gen_exit(struct caam_blob_priv *priv)
 188 {
 189         caam_jr_free(&priv->jrdev);
 190 }
 191 EXPORT_SYMBOL(caam_blob_gen_exit);