diff options
Diffstat (limited to 'drivers/crypto/allwinner/sun8i-ce/sun8i-ce-trng.c')
| -rw-r--r-- | drivers/crypto/allwinner/sun8i-ce/sun8i-ce-trng.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-trng.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-trng.c new file mode 100644 index 000000000000..654328160d19 --- /dev/null +++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-trng.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * sun8i-ce-trng.c - hardware cryptographic offloader for + * Allwinner H3/A64/H5/H2+/H6/R40 SoC + * + * Copyright (C) 2015-2020 Corentin Labbe <clabbe@baylibre.com> + * + * This file handle the TRNG + * + * You could find a link for the datasheet in Documentation/arm/sunxi/README + */ +#include "sun8i-ce.h" +#include <linux/dma-mapping.h> +#include <linux/pm_runtime.h> +#include <linux/hw_random.h> +/* + * Note that according to the algorithm ID, 2 versions of the TRNG exists, + * The first present in H3/H5/R40/A64 and the second present in H6. + * This file adds support for both, but only the second is working + * reliabily according to rngtest. + **/ + +static int sun8i_ce_trng_read(struct hwrng *rng, void *data, size_t max, bool wait) +{ + struct sun8i_ce_dev *ce; + dma_addr_t dma_dst; + int err = 0; + int flow = 3; + unsigned int todo; + struct sun8i_ce_flow *chan; + struct ce_task *cet; + u32 common; + void *d; + + ce = container_of(rng, struct sun8i_ce_dev, trng); + + /* round the data length to a multiple of 32*/ + todo = max + 32; + todo -= todo % 32; + + d = kzalloc(todo, GFP_KERNEL | GFP_DMA); + if (!d) + return -ENOMEM; + +#ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG + ce->hwrng_stat_req++; + ce->hwrng_stat_bytes += todo; +#endif + + dma_dst = dma_map_single(ce->dev, d, todo, DMA_FROM_DEVICE); + if (dma_mapping_error(ce->dev, dma_dst)) { + dev_err(ce->dev, "Cannot DMA MAP DST\n"); + err = -EFAULT; + goto err_dst; + } + + err = pm_runtime_get_sync(ce->dev); + if (err < 0) { + pm_runtime_put_noidle(ce->dev); + goto err_pm; + } + + mutex_lock(&ce->rnglock); + chan = &ce->chanlist[flow]; + + cet = &chan->tl[0]; + memset(cet, 0, sizeof(struct ce_task)); + + cet->t_id = cpu_to_le32(flow); + common = ce->variant->trng | CE_COMM_INT; + cet->t_common_ctl = cpu_to_le32(common); + + /* recent CE (H6) need length in bytes, in word otherwise */ + if (ce->variant->trng_t_dlen_in_bytes) + cet->t_dlen = cpu_to_le32(todo); + else + cet->t_dlen = cpu_to_le32(todo / 4); + + cet->t_sym_ctl = 0; + cet->t_asym_ctl = 0; + + cet->t_dst[0].addr = cpu_to_le32(dma_dst); + cet->t_dst[0].len = cpu_to_le32(todo / 4); + ce->chanlist[flow].timeout = todo; + + err = sun8i_ce_run_task(ce, 3, "TRNG"); + mutex_unlock(&ce->rnglock); + + pm_runtime_put(ce->dev); + +err_pm: + dma_unmap_single(ce->dev, dma_dst, todo, DMA_FROM_DEVICE); + + if (!err) { + memcpy(data, d, max); + err = max; + } + memzero_explicit(d, todo); +err_dst: + kfree(d); + return err; +} + +int sun8i_ce_hwrng_register(struct sun8i_ce_dev *ce) +{ + int ret; + + if (ce->variant->trng == CE_ID_NOTSUPP) { + dev_info(ce->dev, "TRNG not supported\n"); + return 0; + } + ce->trng.name = "sun8i Crypto Engine TRNG"; + ce->trng.read = sun8i_ce_trng_read; + ce->trng.quality = 1000; + + ret = hwrng_register(&ce->trng); + if (ret) + dev_err(ce->dev, "Fail to register the TRNG\n"); + return ret; +} + +void sun8i_ce_hwrng_unregister(struct sun8i_ce_dev *ce) +{ + if (ce->variant->trng == CE_ID_NOTSUPP) + return; + hwrng_unregister(&ce->trng); +} |