RE: [PATCH v8 1/5] crypto: aspeed: Add HACE hash driver

From: Neal Liu
Date: Mon Aug 08 2022 - 05:30:33 EST

> -----Original Message-----
> From: liulongfang <liulongfang@xxxxxxxxxx>
> Sent: Monday, August 8, 2022 10:53 AM
> To: Neal Liu <neal_liu@xxxxxxxxxxxxxx>; Corentin Labbe
> <clabbe.montjoie@xxxxxxxxx>; Christophe JAILLET
> <christophe.jaillet@xxxxxxxxxx>; Randy Dunlap <rdunlap@xxxxxxxxxxxxx>;
> Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>; David S . Miller
> <davem@xxxxxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; Krzysztof
> Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>; Joel Stanley <joel@xxxxxxxxx>;
> Andrew Jeffery <andrew@xxxxxxxx>; Dhananjay Phadke
> <dhphadke@xxxxxxxxxxxxx>; Johnny Huang
> <johnny_huang@xxxxxxxxxxxxxx>
> Cc: linux-aspeed@xxxxxxxxxxxxxxxx; linux-crypto@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; BMC-SW <BMC-SW@xxxxxxxxxxxxxx>
> Subject: Re: [PATCH v8 1/5] crypto: aspeed: Add HACE hash driver
>
>
> On 2022/7/26 19:34, Neal Liu wrote:
> > Hash and Crypto Engine (HACE) is designed to accelerate the
> > throughput of hash data digest, encryption, and decryption.
> >
> > Basically, HACE can be divided into two independently engines
> > - Hash Engine and Crypto Engine. This patch aims to add HACE
> > hash engine driver for hash accelerator.
> >
> > Signed-off-by: Neal Liu <neal_liu@xxxxxxxxxxxxxx>
> > Signed-off-by: Johnny Huang <johnny_huang@xxxxxxxxxxxxxx>
> > ---
> > MAINTAINERS | 7 +
> > drivers/crypto/Kconfig | 1 +
> > drivers/crypto/Makefile | 1 +
> > drivers/crypto/aspeed/Kconfig | 32 +
> > drivers/crypto/aspeed/Makefile | 6 +
> > drivers/crypto/aspeed/aspeed-hace-hash.c | 1389
> ++++++++++++++++++++++
> > drivers/crypto/aspeed/aspeed-hace.c | 213 ++++
> > drivers/crypto/aspeed/aspeed-hace.h | 186 +++
> > 8 files changed, 1835 insertions(+)
> > create mode 100644 drivers/crypto/aspeed/Kconfig
> > create mode 100644 drivers/crypto/aspeed/Makefile
> > create mode 100644 drivers/crypto/aspeed/aspeed-hace-hash.c
> > create mode 100644 drivers/crypto/aspeed/aspeed-hace.c
> > create mode 100644 drivers/crypto/aspeed/aspeed-hace.h
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index f55aea311af5..23a0215b7e42 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -3140,6 +3140,13 @@ S: Maintained
> > F: Documentation/devicetree/bindings/media/aspeed-video.txt
> > F: drivers/media/platform/aspeed/
> >
> > +ASPEED CRYPTO DRIVER
> > +M: Neal Liu <neal_liu@xxxxxxxxxxxxxx>
> > +L: linux-aspeed@xxxxxxxxxxxxxxxx (moderated for non-subscribers)
> > +S: Maintained
> > +F:
> Documentation/devicetree/bindings/crypto/aspeed,ast2500-hace.yaml
> > +F: drivers/crypto/aspeed/
> > +
> > ASUS NOTEBOOKS AND EEEPC ACPI/WMI EXTRAS DRIVERS
> > M: Corentin Chary <corentin.chary@xxxxxxxxx>
> > L: acpi4asus-user@xxxxxxxxxxxxxxxxxxxxx
> > diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
> > index ee99c02c84e8..b9f5ee126881 100644
> > --- a/drivers/crypto/Kconfig
> > +++ b/drivers/crypto/Kconfig
> > @@ -933,5 +933,6 @@ config CRYPTO_DEV_SA2UL
> > acceleration for cryptographic algorithms on these devices.
> >
> > source "drivers/crypto/keembay/Kconfig"
> > +source "drivers/crypto/aspeed/Kconfig"
> >
> > endif # CRYPTO_HW
> > diff --git a/drivers/crypto/Makefile b/drivers/crypto/Makefile
> > index f81703a86b98..116de173a66c 100644
> > --- a/drivers/crypto/Makefile
> > +++ b/drivers/crypto/Makefile
> > @@ -1,5 +1,6 @@
> > # SPDX-License-Identifier: GPL-2.0
> > obj-$(CONFIG_CRYPTO_DEV_ALLWINNER) += allwinner/
> > +obj-$(CONFIG_CRYPTO_DEV_ASPEED) += aspeed/
> > obj-$(CONFIG_CRYPTO_DEV_ATMEL_AES) += atmel-aes.o
> > obj-$(CONFIG_CRYPTO_DEV_ATMEL_SHA) += atmel-sha.o
> > obj-$(CONFIG_CRYPTO_DEV_ATMEL_TDES) += atmel-tdes.o
> > diff --git a/drivers/crypto/aspeed/Kconfig b/drivers/crypto/aspeed/Kconfig
> > new file mode 100644
> > index 000000000000..059e627efef8
> > --- /dev/null
> > +++ b/drivers/crypto/aspeed/Kconfig
> > @@ -0,0 +1,32 @@
> > +config CRYPTO_DEV_ASPEED
> > + tristate "Support for Aspeed cryptographic engine driver"
> > + depends on ARCH_ASPEED
> > + help
> > + Hash and Crypto Engine (HACE) is designed to accelerate the
> > + throughput of hash data digest, encryption and decryption.
> > +
> > + Select y here to have support for the cryptographic driver
> > + available on Aspeed SoC.
> > +
> > +config CRYPTO_DEV_ASPEED_HACE_HASH
> > + bool "Enable Aspeed Hash & Crypto Engine (HACE) hash"
> > + depends on CRYPTO_DEV_ASPEED
> > + select CRYPTO_ENGINE
> > + select CRYPTO_SHA1
> > + select CRYPTO_SHA256
> > + select CRYPTO_SHA512
> > + select CRYPTO_HMAC
> > + help
> > + Select here to enable Aspeed Hash & Crypto Engine (HACE)
> > + hash driver.
> > + Supports multiple message digest standards, including
> > + SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, and so on.
> > +
> > +config CRYPTO_DEV_ASPEED_HACE_HASH_DEBUG
> > + bool "Enable HACE hash debug messages"
> > + depends on CRYPTO_DEV_ASPEED_HACE_HASH
> > + help
> > + Print HACE hash debugging messages if you use this option
> > + to ask for those messages.
> > + Avoid enabling this option for production build to
> > + minimize driver timing.
> > diff --git a/drivers/crypto/aspeed/Makefile
> b/drivers/crypto/aspeed/Makefile
> > new file mode 100644
> > index 000000000000..8bc8d4fed5a9
> > --- /dev/null
> > +++ b/drivers/crypto/aspeed/Makefile
> > @@ -0,0 +1,6 @@
> > +obj-$(CONFIG_CRYPTO_DEV_ASPEED) += aspeed_crypto.o
> > +aspeed_crypto-objs := aspeed-hace.o \
> > + $(hace-hash-y)
> > +
> > +obj-$(CONFIG_CRYPTO_DEV_ASPEED_HACE_HASH) += aspeed-hace-hash.o
> > +hace-hash-$(CONFIG_CRYPTO_DEV_ASPEED_HACE_HASH) :=
> aspeed-hace-hash.o
> > diff --git a/drivers/crypto/aspeed/aspeed-hace-hash.c
> b/drivers/crypto/aspeed/aspeed-hace-hash.c
> > new file mode 100644
> > index 000000000000..63a8ad694996
> > --- /dev/null
> > +++ b/drivers/crypto/aspeed/aspeed-hace-hash.c
> > @@ -0,0 +1,1389 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright (c) 2021 Aspeed Technology Inc.
> > + */
> > +
> > +#include "aspeed-hace.h"
> > +
> > +#ifdef CONFIG_CRYPTO_DEV_ASPEED_HACE_HASH_DEBUG
> > +#define AHASH_DBG(h, fmt, ...) \
> > + dev_info((h)->dev, "%s() " fmt, __func__, ##__VA_ARGS__)
> > +#else
> > +#define AHASH_DBG(h, fmt, ...) \
> > + dev_dbg((h)->dev, "%s() " fmt, __func__, ##__VA_ARGS__)
> > +#endif
> > +
> > +/* Initialization Vectors for SHA-family */
> > +static const __be32 sha1_iv[8] = {
> > + cpu_to_be32(SHA1_H0), cpu_to_be32(SHA1_H1),
> > + cpu_to_be32(SHA1_H2), cpu_to_be32(SHA1_H3),
> > + cpu_to_be32(SHA1_H4), 0, 0, 0
> > +};
> > +
> > +static const __be32 sha224_iv[8] = {
> > + cpu_to_be32(SHA224_H0), cpu_to_be32(SHA224_H1),
> > + cpu_to_be32(SHA224_H2), cpu_to_be32(SHA224_H3),
> > + cpu_to_be32(SHA224_H4), cpu_to_be32(SHA224_H5),
> > + cpu_to_be32(SHA224_H6), cpu_to_be32(SHA224_H7),
> > +};
> > +
> > +static const __be32 sha256_iv[8] = {
> > + cpu_to_be32(SHA256_H0), cpu_to_be32(SHA256_H1),
> > + cpu_to_be32(SHA256_H2), cpu_to_be32(SHA256_H3),
> > + cpu_to_be32(SHA256_H4), cpu_to_be32(SHA256_H5),
> > + cpu_to_be32(SHA256_H6), cpu_to_be32(SHA256_H7),
> > +};
> > +
> > +static const __be64 sha384_iv[8] = {
> > + cpu_to_be64(SHA384_H0), cpu_to_be64(SHA384_H1),
> > + cpu_to_be64(SHA384_H2), cpu_to_be64(SHA384_H3),
> > + cpu_to_be64(SHA384_H4), cpu_to_be64(SHA384_H5),
> > + cpu_to_be64(SHA384_H6), cpu_to_be64(SHA384_H7)
> > +};
> > +
> > +static const __be64 sha512_iv[8] = {
> > + cpu_to_be64(SHA512_H0), cpu_to_be64(SHA512_H1),
> > + cpu_to_be64(SHA512_H2), cpu_to_be64(SHA512_H3),
> > + cpu_to_be64(SHA512_H4), cpu_to_be64(SHA512_H5),
> > + cpu_to_be64(SHA512_H6), cpu_to_be64(SHA512_H7)
> > +};
> > +
> > +static const __be32 sha512_224_iv[16] = {
> > + cpu_to_be32(0xC8373D8CUL), cpu_to_be32(0xA24D5419UL),
> > + cpu_to_be32(0x6699E173UL), cpu_to_be32(0xD6D4DC89UL),
> > + cpu_to_be32(0xAEB7FA1DUL), cpu_to_be32(0x829CFF32UL),
> > + cpu_to_be32(0x14D59D67UL), cpu_to_be32(0xCF9F2F58UL),
> > + cpu_to_be32(0x692B6D0FUL), cpu_to_be32(0xA84DD47BUL),
> > + cpu_to_be32(0x736FE377UL), cpu_to_be32(0x4289C404UL),
> > + cpu_to_be32(0xA8859D3FUL), cpu_to_be32(0xC8361D6AUL),
> > + cpu_to_be32(0xADE61211UL), cpu_to_be32(0xA192D691UL)
> > +};
> > +
> > +static const __be32 sha512_256_iv[16] = {
> > + cpu_to_be32(0x94213122UL), cpu_to_be32(0x2CF72BFCUL),
> > + cpu_to_be32(0xA35F559FUL), cpu_to_be32(0xC2644CC8UL),
> > + cpu_to_be32(0x6BB89323UL), cpu_to_be32(0x51B1536FUL),
> > + cpu_to_be32(0x19773896UL), cpu_to_be32(0xBDEA4059UL),
> > + cpu_to_be32(0xE23E2896UL), cpu_to_be32(0xE3FF8EA8UL),
> > + cpu_to_be32(0x251E5EBEUL), cpu_to_be32(0x92398653UL),
> > + cpu_to_be32(0xFC99012BUL), cpu_to_be32(0xAAB8852CUL),
> > + cpu_to_be32(0xDC2DB70EUL), cpu_to_be32(0xA22CC581UL)
> > +};
> > +
> > +/* The purpose of this padding is to ensure that the padded message is a
> > + * multiple of 512 bits (SHA1/SHA224/SHA256) or 1024 bits
> (SHA384/SHA512).
> > + * The bit "1" is appended at the end of the message followed by
> > + * "padlen-1" zero bits. Then a 64 bits block (SHA1/SHA224/SHA256) or
> > + * 128 bits block (SHA384/SHA512) equals to the message length in bits
> > + * is appended.
> > + *
> > + * For SHA1/SHA224/SHA256, padlen is calculated as followed:
> > + * - if message length < 56 bytes then padlen = 56 - message length
> > + * - else padlen = 64 + 56 - message length
> > + *
> > + * For SHA384/SHA512, padlen is calculated as followed:
> > + * - if message length < 112 bytes then padlen = 112 - message length
> > + * - else padlen = 128 + 112 - message length
> > + */
> > +static void aspeed_ahash_fill_padding(struct aspeed_hace_dev *hace_dev,
> > + struct aspeed_sham_reqctx *rctx)
> > +{
> > + unsigned int index, padlen;
> > + __be64 bits[2];
> > +
> > + AHASH_DBG(hace_dev, "rctx flags:0x%x\n", (u32)rctx->flags);
> > +
> > + switch (rctx->flags & SHA_FLAGS_MASK) {
> > + case SHA_FLAGS_SHA1:
> > + case SHA_FLAGS_SHA224:
> > + case SHA_FLAGS_SHA256:
> > + bits[0] = cpu_to_be64(rctx->digcnt[0] << 3);
> > + index = rctx->bufcnt & 0x3f;
> > + padlen = (index < 56) ? (56 - index) : ((64 + 56) - index);
> > + *(rctx->buffer + rctx->bufcnt) = 0x80;
> > + memset(rctx->buffer + rctx->bufcnt + 1, 0, padlen - 1);
> > + memcpy(rctx->buffer + rctx->bufcnt + padlen, bits, 8);
> > + rctx->bufcnt += padlen + 8;
> > + break;
> > + default:
> > + bits[1] = cpu_to_be64(rctx->digcnt[0] << 3);
> > + bits[0] = cpu_to_be64(rctx->digcnt[1] << 3 |
> > + rctx->digcnt[0] >> 61);
> > + index = rctx->bufcnt & 0x7f;
> > + padlen = (index < 112) ? (112 - index) : ((128 + 112) - index);
> > + *(rctx->buffer + rctx->bufcnt) = 0x80;
> > + memset(rctx->buffer + rctx->bufcnt + 1, 0, padlen - 1);
> > + memcpy(rctx->buffer + rctx->bufcnt + padlen, bits, 16);
> > + rctx->bufcnt += padlen + 16;
> > + break;
> > + }
> > +}
> > +
> > +/*
> > + * Prepare DMA buffer before hardware engine
> > + * processing.
> > + */
> > +static int aspeed_ahash_dma_prepare(struct aspeed_hace_dev *hace_dev)
> > +{
> > + struct aspeed_engine_hash *hash_engine = &hace_dev->hash_engine;
> > + struct ahash_request *req = hash_engine->req;
> > + struct aspeed_sham_reqctx *rctx = ahash_request_ctx(req);
> > + int length, remain;
> > +
> > + length = rctx->total + rctx->bufcnt;
> > + remain = length % rctx->block_size;
> > +
> > + AHASH_DBG(hace_dev, "length:0x%x, remain:0x%x\n", length, remain);
> > +
> > + if (rctx->bufcnt)
> > + memcpy(hash_engine->ahash_src_addr, rctx->buffer, rctx->bufcnt);
> > +
> > + if (rctx->total + rctx->bufcnt < ASPEED_CRYPTO_SRC_DMA_BUF_LEN) {
> > + scatterwalk_map_and_copy(hash_engine->ahash_src_addr +
> > + rctx->bufcnt, rctx->src_sg,
> > + rctx->offset, rctx->total - remain, 0);
> > + rctx->offset += rctx->total - remain;
> > +
> > + } else {
> > + dev_warn(hace_dev->dev, "Hash data length is too large\n");
> > + return -EINVAL;
> > + }
> > +
> > + scatterwalk_map_and_copy(rctx->buffer, rctx->src_sg,
> > + rctx->offset, remain, 0);
> > +
> > + rctx->bufcnt = remain;
> > + rctx->digest_dma_addr = dma_map_single(hace_dev->dev, rctx->digest,
> > + SHA512_DIGEST_SIZE,
> > + DMA_BIDIRECTIONAL);
> > + if (dma_mapping_error(hace_dev->dev, rctx->digest_dma_addr)) {
> > + dev_warn(hace_dev->dev, "dma_map() rctx digest error\n");
> > + return -ENOMEM;
> > + }
> > +
> > + hash_engine->src_length = length - remain;
> > + hash_engine->src_dma = hash_engine->ahash_src_dma_addr;
> > + hash_engine->digest_dma = rctx->digest_dma_addr;
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Prepare DMA buffer as SG list buffer before
> > + * hardware engine processing.
> > + */
> > +static int aspeed_ahash_dma_prepare_sg(struct aspeed_hace_dev
> *hace_dev)
> > +{
> > + struct aspeed_engine_hash *hash_engine = &hace_dev->hash_engine;
> > + struct ahash_request *req = hash_engine->req;
> > + struct aspeed_sham_reqctx *rctx = ahash_request_ctx(req);
> > + struct aspeed_sg_list *src_list;
> > + struct scatterlist *s;
> > + int length, remain, sg_len, i;
> > + int rc = 0;
> > +
> > + remain = (rctx->total + rctx->bufcnt) % rctx->block_size;
> > + length = rctx->total + rctx->bufcnt - remain;
> > +
> > + AHASH_DBG(hace_dev, "%s:0x%x, %s:0x%x, %s:0x%x, %s:0x%x\n",
> > + "rctx total", rctx->total, "bufcnt", rctx->bufcnt,
> > + "length", length, "remain", remain);
> > +
> > + sg_len = dma_map_sg(hace_dev->dev, rctx->src_sg, rctx->src_nents,
> > + DMA_TO_DEVICE);
> > + if (!sg_len) {
> > + dev_warn(hace_dev->dev, "dma_map_sg() src error\n");
> > + rc = -ENOMEM;
> > + goto end;
> > + }
> > +
> > + src_list = (struct aspeed_sg_list *)hash_engine->ahash_src_addr;
> > + rctx->digest_dma_addr = dma_map_single(hace_dev->dev, rctx->digest,
> > + SHA512_DIGEST_SIZE,
> > + DMA_BIDIRECTIONAL);
> > + if (dma_mapping_error(hace_dev->dev, rctx->digest_dma_addr)) {
> > + dev_warn(hace_dev->dev, "dma_map() rctx digest error\n");
> > + rc = -ENOMEM;
> > + goto free_src_sg;
> > + }
> > +
> > + if (rctx->bufcnt != 0) {
> > + rctx->buffer_dma_addr = dma_map_single(hace_dev->dev,
> > + rctx->buffer,
> > + rctx->block_size * 2,
> > + DMA_TO_DEVICE);
> > + if (dma_mapping_error(hace_dev->dev, rctx->buffer_dma_addr)) {
> > + dev_warn(hace_dev->dev, "dma_map() rctx buffer error\n");
> > + rc = -ENOMEM;
> > + goto free_rctx_digest;
> > + }
> > +
> > + src_list[0].phy_addr = rctx->buffer_dma_addr;
> > + src_list[0].len = rctx->bufcnt;
> > + length -= src_list[0].len;
> > +
> > + /* Last sg list */
> > + if (length == 0)
> > + src_list[0].len |= HASH_SG_LAST_LIST;
> > +
> > + src_list[0].phy_addr = cpu_to_le32(src_list[0].phy_addr);
> > + src_list[0].len = cpu_to_le32(src_list[0].len);
> > + src_list++;
> > + }
> > +
> > + if (length != 0) {
> > + for_each_sg(rctx->src_sg, s, sg_len, i) {
> > + src_list[i].phy_addr = sg_dma_address(s);
> > +
> > + if (length > sg_dma_len(s)) {
> > + src_list[i].len = sg_dma_len(s);
> > + length -= sg_dma_len(s);
> > +
> > + } else {
> > + /* Last sg list */
> > + src_list[i].len = length;
> > + src_list[i].len |= HASH_SG_LAST_LIST;
> > + length = 0;
> > + }
> > +
> > + src_list[i].phy_addr = cpu_to_le32(src_list[i].phy_addr);
> > + src_list[i].len = cpu_to_le32(src_list[i].len);
> > + }
> > + }
> > +
> > + if (length != 0) {
> > + rc = -EINVAL;
> > + goto free_rctx_buffer;
> > + }
> > +
> > + rctx->offset = rctx->total - remain;
> > + hash_engine->src_length = rctx->total + rctx->bufcnt - remain;
> > + hash_engine->src_dma = hash_engine->ahash_src_dma_addr;
> > + hash_engine->digest_dma = rctx->digest_dma_addr;
> > +
> > + goto end;
> Exiting via "goto xx" is not recommended in normal code logic (this requires
> two jumps),
> exiting via "return 0" is more efficient.
> This code method has many times in your entire driver, it is recommended to
> modify it.

If not exiting via "goto xx", how to release related resources without any problem?
Is there any proper way to do this?

> > +
> > +free_rctx_buffer:
> > + if (rctx->bufcnt != 0)
> > + dma_unmap_single(hace_dev->dev, rctx->buffer_dma_addr,
> > + rctx->block_size * 2, DMA_TO_DEVICE);
> > +free_rctx_digest:
> > + dma_unmap_single(hace_dev->dev, rctx->digest_dma_addr,
> > + SHA512_DIGEST_SIZE, DMA_BIDIRECTIONAL);
> > +free_src_sg:
> > + dma_unmap_sg(hace_dev->dev, rctx->src_sg, rctx->src_nents,
> > + DMA_TO_DEVICE);
> > +end:
> > + return rc;
> > +}
> > +
> > +static int aspeed_ahash_complete(struct aspeed_hace_dev *hace_dev)
> > +{
> > + struct aspeed_engine_hash *hash_engine = &hace_dev->hash_engine;
> > + struct ahash_request *req = hash_engine->req;
> > +
> > + AHASH_DBG(hace_dev, "\n");
> > +
> > + hash_engine->flags &= ~CRYPTO_FLAGS_BUSY;
> > +
> > + crypto_finalize_hash_request(hace_dev->crypt_engine_hash, req, 0);
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Copy digest to the corresponding request result.
> > + * This function will be called at final() stage.
> > + */
> > +static int aspeed_ahash_transfer(struct aspeed_hace_dev *hace_dev)
> > +{
> > + struct aspeed_engine_hash *hash_engine = &hace_dev->hash_engine;
> > + struct ahash_request *req = hash_engine->req;
> > + struct aspeed_sham_reqctx *rctx = ahash_request_ctx(req);
> > +
> > + AHASH_DBG(hace_dev, "\n");
> > +
> > + dma_unmap_single(hace_dev->dev, rctx->digest_dma_addr,
> > + SHA512_DIGEST_SIZE, DMA_BIDIRECTIONAL);
> > +
> > + dma_unmap_single(hace_dev->dev, rctx->buffer_dma_addr,
> > + rctx->block_size * 2, DMA_TO_DEVICE);
> > +
> > + memcpy(req->result, rctx->digest, rctx->digsize);
> > +
> > + return aspeed_ahash_complete(hace_dev);
> > +}
> > +
> > +/*
> > + * Trigger hardware engines to do the math.
> > + */
> > +static int aspeed_hace_ahash_trigger(struct aspeed_hace_dev *hace_dev,
> > + aspeed_hace_fn_t resume)
> > +{
> > + struct aspeed_engine_hash *hash_engine = &hace_dev->hash_engine;
> > + struct ahash_request *req = hash_engine->req;
> > + struct aspeed_sham_reqctx *rctx = ahash_request_ctx(req);
> > +
> > + AHASH_DBG(hace_dev, "src_dma:0x%x, digest_dma:0x%x,
> length:0x%x\n",
> > + hash_engine->src_dma, hash_engine->digest_dma,
> > + hash_engine->src_length);
> > +
> > + rctx->cmd |= HASH_CMD_INT_ENABLE;
> > + hash_engine->resume = resume;
> > +
> > + ast_hace_write(hace_dev, hash_engine->src_dma,
> ASPEED_HACE_HASH_SRC);
> > + ast_hace_write(hace_dev, hash_engine->digest_dma,
> > + ASPEED_HACE_HASH_DIGEST_BUFF);
> > + ast_hace_write(hace_dev, hash_engine->digest_dma,
> > + ASPEED_HACE_HASH_KEY_BUFF);
> > + ast_hace_write(hace_dev, hash_engine->src_length,
> > + ASPEED_HACE_HASH_DATA_LEN);
> > +
> > + /* Memory barrier to ensure all data setup before engine starts */
> > + mb();
> > +
> > + ast_hace_write(hace_dev, rctx->cmd, ASPEED_HACE_HASH_CMD);
> A hardware service sending requires 5 hardware commands to complete.
> In a multi-concurrency scenario, how to ensure the order of commands?
> (If two processes send hardware task at the same time,
> How to ensure that the hardware recognizes which task the current
> command belongs to?)

Linux crypto engine would guarantee that only one request at each time to be dequeued from engine queue to process.
And there has lock mechanism inside Linux crypto engine to prevent the scenario you mentioned.
So only 1 aspeed_hace_ahash_trigger() hardware service would go through at a time.

[...]