cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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sun8i-ce-prng.c (3794B)

      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
     17int 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
     25void sun8i_ce_prng_exit(struct crypto_tfm *tfm)
     26{
     27	struct sun8i_ce_rng_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
     28
     29	kfree_sensitive(ctx->seed);
     30	ctx->seed = NULL;
     31	ctx->slen = 0;
     32}
     33
     34int sun8i_ce_prng_seed(struct crypto_rng *tfm, const u8 *seed,
     35		       unsigned int slen)
     36{
     37	struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
     38
     39	if (ctx->seed && ctx->slen != slen) {
     40		kfree_sensitive(ctx->seed);
     41		ctx->slen = 0;
     42		ctx->seed = NULL;
     43	}
     44	if (!ctx->seed)
     45		ctx->seed = kmalloc(slen, GFP_KERNEL | GFP_DMA);
     46	if (!ctx->seed)
     47		return -ENOMEM;
     48
     49	memcpy(ctx->seed, seed, slen);
     50	ctx->slen = slen;
     51
     52	return 0;
     53}
     54
     55int sun8i_ce_prng_generate(struct crypto_rng *tfm, const u8 *src,
     56			   unsigned int slen, u8 *dst, unsigned int dlen)
     57{
     58	struct sun8i_ce_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
     59	struct rng_alg *alg = crypto_rng_alg(tfm);
     60	struct sun8i_ce_alg_template *algt;
     61	struct sun8i_ce_dev *ce;
     62	dma_addr_t dma_iv, dma_dst;
     63	int err = 0;
     64	int flow = 3;
     65	unsigned int todo;
     66	struct sun8i_ce_flow *chan;
     67	struct ce_task *cet;
     68	u32 common, sym;
     69	void *d;
     70
     71	algt = container_of(alg, struct sun8i_ce_alg_template, alg.rng);
     72	ce = algt->ce;
     73
     74	if (ctx->slen == 0) {
     75		dev_err(ce->dev, "not seeded\n");
     76		return -EINVAL;
     77	}
     78
     79	/* we want dlen + seedsize rounded up to a multiple of PRNG_DATA_SIZE */
     80	todo = dlen + ctx->slen + PRNG_DATA_SIZE * 2;
     81	todo -= todo % PRNG_DATA_SIZE;
     82
     83	d = kzalloc(todo, GFP_KERNEL | GFP_DMA);
     84	if (!d) {
     85		err = -ENOMEM;
     86		goto err_mem;
     87	}
     88
     89	dev_dbg(ce->dev, "%s PRNG slen=%u dlen=%u todo=%u multi=%u\n", __func__,
     90		slen, dlen, todo, todo / PRNG_DATA_SIZE);
     91
     92#ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG
     93	algt->stat_req++;
     94	algt->stat_bytes += todo;
     95#endif
     96
     97	dma_iv = dma_map_single(ce->dev, ctx->seed, ctx->slen, DMA_TO_DEVICE);
     98	if (dma_mapping_error(ce->dev, dma_iv)) {
     99		dev_err(ce->dev, "Cannot DMA MAP IV\n");
    100		err = -EFAULT;
    101		goto err_iv;
    102	}
    103
    104	dma_dst = dma_map_single(ce->dev, d, todo, DMA_FROM_DEVICE);
    105	if (dma_mapping_error(ce->dev, dma_dst)) {
    106		dev_err(ce->dev, "Cannot DMA MAP DST\n");
    107		err = -EFAULT;
    108		goto err_dst;
    109	}
    110
    111	err = pm_runtime_resume_and_get(ce->dev);
    112	if (err < 0)
    113		goto err_pm;
    114
    115	mutex_lock(&ce->rnglock);
    116	chan = &ce->chanlist[flow];
    117
    118	cet = &chan->tl[0];
    119	memset(cet, 0, sizeof(struct ce_task));
    120
    121	cet->t_id = cpu_to_le32(flow);
    122	common = ce->variant->prng | CE_COMM_INT;
    123	cet->t_common_ctl = cpu_to_le32(common);
    124
    125	/* recent CE (H6) need length in bytes, in word otherwise */
    126	if (ce->variant->prng_t_dlen_in_bytes)
    127		cet->t_dlen = cpu_to_le32(todo);
    128	else
    129		cet->t_dlen = cpu_to_le32(todo / 4);
    130
    131	sym = PRNG_LD;
    132	cet->t_sym_ctl = cpu_to_le32(sym);
    133	cet->t_asym_ctl = 0;
    134
    135	cet->t_key = cpu_to_le32(dma_iv);
    136	cet->t_iv = cpu_to_le32(dma_iv);
    137
    138	cet->t_dst[0].addr = cpu_to_le32(dma_dst);
    139	cet->t_dst[0].len = cpu_to_le32(todo / 4);
    140	ce->chanlist[flow].timeout = 2000;
    141
    142	err = sun8i_ce_run_task(ce, 3, "PRNG");
    143	mutex_unlock(&ce->rnglock);
    144
    145	pm_runtime_put(ce->dev);
    146
    147err_pm:
    148	dma_unmap_single(ce->dev, dma_dst, todo, DMA_FROM_DEVICE);
    149err_dst:
    150	dma_unmap_single(ce->dev, dma_iv, ctx->slen, DMA_TO_DEVICE);
    151
    152	if (!err) {
    153		memcpy(dst, d, dlen);
    154		memcpy(ctx->seed, d + dlen, ctx->slen);
    155	}
    156err_iv:
    157	kfree_sensitive(d);
    158err_mem:
    159	return err;
    160}