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// SPDX-License-Identifier: GPL-2.0
/*
* sun8i-ce-prng.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 PRNG
*
* You could find a link for the datasheet in Documentation/arm/sunxi.rst
*/
#include "sun8i-ce.h"
#include <linux/dma-mapping.h>
#include <linux/pm_runtime.h>
#include <crypto/internal/rng.h>
int sun8i_ce_prng_init(struct crypto_tfm *tfm)
{
struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
memset(ctx, 0, sizeof(struct sun8i_ce_rng_tfm_ctx));
return 0;
}
void sun8i_ce_prng_exit(struct crypto_tfm *tfm)
{
struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
memzero_explicit(ctx->seed, ctx->slen);
kfree(ctx->seed);
ctx->seed = NULL;
ctx->slen = 0;
}
int sun8i_ce_prng_seed(struct crypto_rng *tfm, const u8 *seed,
unsigned int slen)
{
struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
if (ctx->seed && ctx->slen != slen) {
memzero_explicit(ctx->seed, ctx->slen);
kfree(ctx->seed);
ctx->slen = 0;
ctx->seed = NULL;
}
if (!ctx->seed)
ctx->seed = kmalloc(slen, GFP_KERNEL | GFP_DMA);
if (!ctx->seed)
return -ENOMEM;
memcpy(ctx->seed, seed, slen);
ctx->slen = slen;
return 0;
}
int sun8i_ce_prng_generate(struct crypto_rng *tfm, const u8 *src,
unsigned int slen, u8 *dst, unsigned int dlen)
{
struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
struct rng_alg *alg = crypto_rng_alg(tfm);
struct sun8i_ce_alg_template *algt;
struct sun8i_ce_dev *ce;
dma_addr_t dma_iv, dma_dst;
int err = 0;
int flow = 3;
unsigned int todo;
struct sun8i_ce_flow *chan;
struct ce_task *cet;
u32 common, sym;
void *d;
algt = container_of(alg, struct sun8i_ce_alg_template, alg.rng);
ce = algt->ce;
if (ctx->slen == 0) {
dev_err(ce->dev, "not seeded\n");
return -EINVAL;
}
/* we want dlen + seedsize rounded up to a multiple of PRNG_DATA_SIZE */
todo = dlen + ctx->slen + PRNG_DATA_SIZE * 2;
todo -= todo % PRNG_DATA_SIZE;
d = kzalloc(todo, GFP_KERNEL | GFP_DMA);
if (!d) {
err = -ENOMEM;
goto err_mem;
}
dev_dbg(ce->dev, "%s PRNG slen=%u dlen=%u todo=%u multi=%u\n", __func__,
slen, dlen, todo, todo / PRNG_DATA_SIZE);
#ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG
algt->stat_req++;
algt->stat_bytes += todo;
#endif
dma_iv = dma_map_single(ce->dev, ctx->seed, ctx->slen, DMA_TO_DEVICE);
if (dma_mapping_error(ce->dev, dma_iv)) {
dev_err(ce->dev, "Cannot DMA MAP IV\n");
goto err_iv;
}
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->prng | CE_COMM_INT;
cet->t_common_ctl = cpu_to_le32(common);
/* recent CE (H6) need length in bytes, in word otherwise */
if (ce->variant->prng_t_dlen_in_bytes)
cet->t_dlen = cpu_to_le32(todo);
else
cet->t_dlen = cpu_to_le32(todo / 4);
sym = PRNG_LD;
cet->t_sym_ctl = cpu_to_le32(sym);
cet->t_asym_ctl = 0;
cet->t_key = cpu_to_le32(dma_iv);
cet->t_iv = cpu_to_le32(dma_iv);
cet->t_dst[0].addr = cpu_to_le32(dma_dst);
cet->t_dst[0].len = cpu_to_le32(todo / 4);
ce->chanlist[flow].timeout = 2000;
err = sun8i_ce_run_task(ce, 3, "PRNG");
mutex_unlock(&ce->rnglock);
pm_runtime_put(ce->dev);
err_pm:
dma_unmap_single(ce->dev, dma_dst, todo, DMA_FROM_DEVICE);
err_dst:
dma_unmap_single(ce->dev, dma_iv, ctx->slen, DMA_TO_DEVICE);
if (!err) {
memcpy(dst, d, dlen);
memcpy(ctx->seed, d + dlen, ctx->slen);
}
memzero_explicit(d, todo);
err_iv:
kfree(d);
err_mem:
return err;
}