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