diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/crypto/caam/caamprng.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/drivers/crypto/caam/caamprng.c b/drivers/crypto/caam/caamprng.c new file mode 100644 index 000000000..4839e6630 --- /dev/null +++ b/drivers/crypto/caam/caamprng.c @@ -0,0 +1,235 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver to expose SEC4 PRNG via crypto RNG API + * + * Copyright 2022 NXP + * + */ + +#include <linux/completion.h> +#include <crypto/internal/rng.h> +#include "compat.h" +#include "regs.h" +#include "intern.h" +#include "desc_constr.h" +#include "jr.h" +#include "error.h" + +/* + * Length of used descriptors, see caam_init_desc() + */ +#define CAAM_PRNG_MAX_DESC_LEN (CAAM_CMD_SZ + \ + CAAM_CMD_SZ + \ + CAAM_CMD_SZ + CAAM_PTR_SZ_MAX) + +/* prng per-device context */ +struct caam_prng_ctx { + int err; + struct completion done; +}; + +struct caam_prng_alg { + struct rng_alg rng; + bool registered; +}; + +static void caam_prng_done(struct device *jrdev, u32 *desc, u32 err, + void *context) +{ + struct caam_prng_ctx *jctx = context; + + jctx->err = err ? caam_jr_strstatus(jrdev, err) : 0; + + complete(&jctx->done); +} + +static u32 *caam_init_reseed_desc(u32 *desc) +{ + init_job_desc(desc, 0); /* + 1 cmd_sz */ + /* Generate random bytes: + 1 cmd_sz */ + append_operation(desc, OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG | + OP_ALG_AS_FINALIZE); + + print_hex_dump_debug("prng reseed desc@: ", DUMP_PREFIX_ADDRESS, + 16, 4, desc, desc_bytes(desc), 1); + + return desc; +} + +static u32 *caam_init_prng_desc(u32 *desc, dma_addr_t dst_dma, u32 len) +{ + init_job_desc(desc, 0); /* + 1 cmd_sz */ + /* Generate random bytes: + 1 cmd_sz */ + append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG); + /* Store bytes: + 1 cmd_sz + caam_ptr_sz */ + append_fifo_store(desc, dst_dma, + len, FIFOST_TYPE_RNGSTORE); + + print_hex_dump_debug("prng job desc@: ", DUMP_PREFIX_ADDRESS, + 16, 4, desc, desc_bytes(desc), 1); + + return desc; +} + +static int caam_prng_generate(struct crypto_rng *tfm, + const u8 *src, unsigned int slen, + u8 *dst, unsigned int dlen) +{ + struct caam_prng_ctx ctx; + struct device *jrdev; + dma_addr_t dst_dma; + u32 *desc; + u8 *buf; + int ret; + + buf = kzalloc(dlen, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + jrdev = caam_jr_alloc(); + ret = PTR_ERR_OR_ZERO(jrdev); + if (ret) { + pr_err("Job Ring Device allocation failed\n"); + kfree(buf); + return ret; + } + + desc = kzalloc(CAAM_PRNG_MAX_DESC_LEN, GFP_KERNEL | GFP_DMA); + if (!desc) { + ret = -ENOMEM; + goto out1; + } + + dst_dma = dma_map_single(jrdev, buf, dlen, DMA_FROM_DEVICE); + if (dma_mapping_error(jrdev, dst_dma)) { + dev_err(jrdev, "Failed to map destination buffer memory\n"); + ret = -ENOMEM; + goto out; + } + + init_completion(&ctx.done); + ret = caam_jr_enqueue(jrdev, + caam_init_prng_desc(desc, dst_dma, dlen), + caam_prng_done, &ctx); + + if (ret == -EINPROGRESS) { + wait_for_completion(&ctx.done); + ret = ctx.err; + } + + dma_unmap_single(jrdev, dst_dma, dlen, DMA_FROM_DEVICE); + + if (!ret) + memcpy(dst, buf, dlen); +out: + kfree(desc); +out1: + caam_jr_free(jrdev); + kfree(buf); + return ret; +} + +static void caam_prng_exit(struct crypto_tfm *tfm) {} + +static int caam_prng_init(struct crypto_tfm *tfm) +{ + return 0; +} + +static int caam_prng_seed(struct crypto_rng *tfm, + const u8 *seed, unsigned int slen) +{ + struct caam_prng_ctx ctx; + struct device *jrdev; + u32 *desc; + int ret; + + if (slen) { + pr_err("Seed length should be zero\n"); + return -EINVAL; + } + + jrdev = caam_jr_alloc(); + ret = PTR_ERR_OR_ZERO(jrdev); + if (ret) { + pr_err("Job Ring Device allocation failed\n"); + return ret; + } + + desc = kzalloc(CAAM_PRNG_MAX_DESC_LEN, GFP_KERNEL | GFP_DMA); + if (!desc) { + caam_jr_free(jrdev); + return -ENOMEM; + } + + init_completion(&ctx.done); + ret = caam_jr_enqueue(jrdev, + caam_init_reseed_desc(desc), + caam_prng_done, &ctx); + + if (ret == -EINPROGRESS) { + wait_for_completion(&ctx.done); + ret = ctx.err; + } + + kfree(desc); + caam_jr_free(jrdev); + return ret; +} + +static struct caam_prng_alg caam_prng_alg = { + .rng = { + .generate = caam_prng_generate, + .seed = caam_prng_seed, + .seedsize = 0, + .base = { + .cra_name = "stdrng", + .cra_driver_name = "prng-caam", + .cra_priority = 500, + .cra_ctxsize = sizeof(struct caam_prng_ctx), + .cra_module = THIS_MODULE, + .cra_init = caam_prng_init, + .cra_exit = caam_prng_exit, + }, + } +}; + +void caam_prng_unregister(void *data) +{ + if (caam_prng_alg.registered) + crypto_unregister_rng(&caam_prng_alg.rng); +} + +int caam_prng_register(struct device *ctrldev) +{ + struct caam_drv_private *priv = dev_get_drvdata(ctrldev); + u32 rng_inst; + int ret = 0; + + /* Check for available RNG blocks before registration */ + if (priv->era < 10) + rng_inst = (rd_reg32(&priv->jr[0]->perfmon.cha_num_ls) & + CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT; + else + rng_inst = rd_reg32(&priv->jr[0]->vreg.rng) & CHA_VER_NUM_MASK; + + if (!rng_inst) { + dev_dbg(ctrldev, "RNG block is not available... skipping registering algorithm\n"); + return ret; + } + + ret = crypto_register_rng(&caam_prng_alg.rng); + if (ret) { + dev_err(ctrldev, + "couldn't register rng crypto alg: %d\n", + ret); + return ret; + } + + caam_prng_alg.registered = true; + + dev_info(ctrldev, + "rng crypto API alg registered %s\n", caam_prng_alg.rng.base.cra_driver_name); + + return 0; +} |