1 // SPDX-License-Identifier: GPL-2.0
3  * sun8i-ss-prng.c - hardware cryptographic offloader for
6  * Copyright (C) 2015-2020 Corentin Labbe <clabbe@baylibre.com>
12 #include "sun8i-ss.h"
13 #include <linux/dma-mapping.h>
19 int sun8i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed,  in sun8i_ss_prng_seed()  argument
24 	if (ctx->seed && ctx->slen != slen) {  in sun8i_ss_prng_seed()
25 		kfree_sensitive(ctx->seed);  in sun8i_ss_prng_seed()
26 		ctx->slen = 0;  in sun8i_ss_prng_seed()
27 		ctx->seed = NULL;  in sun8i_ss_prng_seed()
29 	if (!ctx->seed)  in sun8i_ss_prng_seed()
30 		ctx->seed = kmalloc(slen, GFP_KERNEL);  in sun8i_ss_prng_seed()
31 	if (!ctx->seed)  in sun8i_ss_prng_seed()
32 		return -ENOMEM;  in sun8i_ss_prng_seed()
34 	memcpy(ctx->seed, seed, slen);  in sun8i_ss_prng_seed()
35 	ctx->slen = slen;  in sun8i_ss_prng_seed()
52 	kfree_sensitive(ctx->seed);  in sun8i_ss_prng_exit()
53 	ctx->seed = NULL;  in sun8i_ss_prng_exit()
54 	ctx->slen = 0;  in sun8i_ss_prng_exit()
73 	ss = algt->ss;  in sun8i_ss_prng_generate()
75 	if (ctx->slen == 0) {  in sun8i_ss_prng_generate()
76 		dev_err(ss->dev, "The PRNG is not seeded\n");  in sun8i_ss_prng_generate()
77 		return -EINVAL;  in sun8i_ss_prng_generate()
80 	/* The SS does not give an updated seed, so we need to get a new one.  in sun8i_ss_prng_generate()
85 	todo -= todo % PRNG_DATA_SIZE;  in sun8i_ss_prng_generate()
89 		return -EOVERFLOW;  in sun8i_ss_prng_generate()
93 		return -ENOMEM;  in sun8i_ss_prng_generate()
98 	algt->stat_req++;  in sun8i_ss_prng_generate()
99 	algt->stat_bytes += todo;  in sun8i_ss_prng_generate()
108 	dma_iv = dma_map_single(ss->dev, ctx->seed, ctx->slen, DMA_TO_DEVICE);  in sun8i_ss_prng_generate()
109 	if (dma_mapping_error(ss->dev, dma_iv)) {  in sun8i_ss_prng_generate()
110 		dev_err(ss->dev, "Cannot DMA MAP IV\n");  in sun8i_ss_prng_generate()
111 		err = -EFAULT;  in sun8i_ss_prng_generate()
115 	dma_dst = dma_map_single(ss->dev, d, todo, DMA_FROM_DEVICE);  in sun8i_ss_prng_generate()
116 	if (dma_mapping_error(ss->dev, dma_dst)) {  in sun8i_ss_prng_generate()
117 		dev_err(ss->dev, "Cannot DMA MAP DST\n");  in sun8i_ss_prng_generate()
118 		err = -EFAULT;  in sun8i_ss_prng_generate()
122 	err = pm_runtime_resume_and_get(ss->dev);  in sun8i_ss_prng_generate()
127 	mutex_lock(&ss->mlock);  in sun8i_ss_prng_generate()
128 	writel(dma_iv, ss->base + SS_IV_ADR_REG);  in sun8i_ss_prng_generate()
130 	writel(dma_iv, ss->base + SS_KEY_ADR_REG);  in sun8i_ss_prng_generate()
131 	writel(dma_dst, ss->base + SS_DST_ADR_REG);  in sun8i_ss_prng_generate()
132 	writel(todo / 4, ss->base + SS_LEN_ADR_REG);  in sun8i_ss_prng_generate()
134 	reinit_completion(&ss->flows[flow].complete);  in sun8i_ss_prng_generate()
135 	ss->flows[flow].status = 0;  in sun8i_ss_prng_generate()
139 	writel(v, ss->base + SS_CTL_REG);  in sun8i_ss_prng_generate()
141 	wait_for_completion_interruptible_timeout(&ss->flows[flow].complete,  in sun8i_ss_prng_generate()
143 	if (ss->flows[flow].status == 0) {  in sun8i_ss_prng_generate()
144 		dev_err(ss->dev, "DMA timeout for PRNG (size=%u)\n", todo);  in sun8i_ss_prng_generate()
145 		err = -EFAULT;  in sun8i_ss_prng_generate()
159 	mutex_unlock(&ss->mlock);  in sun8i_ss_prng_generate()
161 	pm_runtime_put(ss->dev);  in sun8i_ss_prng_generate()
164 	dma_unmap_single(ss->dev, dma_dst, todo, DMA_FROM_DEVICE);  in sun8i_ss_prng_generate()
166 	dma_unmap_single(ss->dev, dma_iv, ctx->slen, DMA_TO_DEVICE);  in sun8i_ss_prng_generate()
170 		/* Update seed */  in sun8i_ss_prng_generate()
171 		memcpy(ctx->seed, d + dlen, ctx->slen);  in sun8i_ss_prng_generate()