[PATCH next v7 07/12] crypto: aspeed: Add AST2600 ACRY support

Joel Stanley joel at jms.id.au
Thu Oct 21 02:24:53 CEST 2021


On Wed, 20 Oct 2021 at 02:50, Chia-Wei Wang <chiawei_wang at aspeedtech.com> wrote:
>
> ACRY is deisnged to accerlerate ECC/RSA digital signature

designed
accelerate

> generation and verification.
>
> Signed-off-by: Chia-Wei Wang <chiawei_wang at aspeedtech.com>
> ---
>  drivers/crypto/aspeed/Kconfig       |  10 ++
>  drivers/crypto/aspeed/Makefile      |   1 +
>  drivers/crypto/aspeed/aspeed_acry.c | 190 ++++++++++++++++++++++++++++
>  lib/rsa/Kconfig                     |  10 +-
>  4 files changed, 210 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/crypto/aspeed/aspeed_acry.c
>
> diff --git a/drivers/crypto/aspeed/Kconfig b/drivers/crypto/aspeed/Kconfig
> index 471c06f986..9bf317177a 100644
> --- a/drivers/crypto/aspeed/Kconfig
> +++ b/drivers/crypto/aspeed/Kconfig
> @@ -8,3 +8,13 @@ config ASPEED_HACE
>           Enabling this allows the use of SHA operations in hardware without
>           requiring the SHA software implementations. It also improves performance
>           and saves code size.
> +
> +config ASPEED_ACRY
> +       bool "ASPEED RSA and ECC Engine"
> +       depends on ASPEED_AST2600
> +       help
> +        Select this option to enable a driver for using the RSA/ECC engine in
> +        the ASPEED BMC SoCs.
> +
> +        Enabling this allows the use of RSA/ECC operations in hardware without requiring the
> +        software implementations. It also improves performance and saves code size.
> diff --git a/drivers/crypto/aspeed/Makefile b/drivers/crypto/aspeed/Makefile
> index 84e6bfe82a..58b55fc46e 100644
> --- a/drivers/crypto/aspeed/Makefile
> +++ b/drivers/crypto/aspeed/Makefile
> @@ -1 +1,2 @@
>  obj-$(CONFIG_ASPEED_HACE) += aspeed_hace.o
> +obj-$(CONFIG_ASPEED_ACRY) += aspeed_acry.o
> diff --git a/drivers/crypto/aspeed/aspeed_acry.c b/drivers/crypto/aspeed/aspeed_acry.c
> new file mode 100644
> index 0000000000..c28cdf374b
> --- /dev/null
> +++ b/drivers/crypto/aspeed/aspeed_acry.c
> @@ -0,0 +1,190 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright 2021 ASPEED Technology Inc.
> + */
> +#include <config.h>
> +#include <common.h>
> +#include <clk.h>
> +#include <dm.h>
> +#include <asm/types.h>
> +#include <asm/io.h>
> +#include <dm/device.h>
> +#include <dm/fdtaddr.h>
> +#include <linux/delay.h>
> +#include <u-boot/rsa-mod-exp.h>
> +
> +/* ACRY register offsets */
> +#define ACRY_CTRL1             0x00
> +#define   ACRY_CTRL1_RSA_DMA           BIT(1)
> +#define   ACRY_CTRL1_RSA_START         BIT(0)
> +#define ACRY_CTRL2             0x44
> +#define ACRY_CTRL3             0x48
> +#define   ACRY_CTRL3_SRAM_AHB_ACCESS   BIT(8)
> +#define   ACRY_CTRL3_ECC_RSA_MODE_MASK GENMASK(5, 4)
> +#define   ACRY_CTRL3_ECC_RSA_MODE_SHIFT        4
> +#define ACRY_DMA_DRAM_SADDR    0x4c
> +#define ACRY_DMA_DMEM_TADDR    0x50
> +#define   ACRY_DMA_DMEM_TADDR_LEN_MASK GENMASK(15, 0)
> +#define   ACRY_DMA_DMEM_TADDR_LEN_SHIFT        0
> +#define ACRY_RSA_PARAM         0x58
> +#define   ACRY_RSA_PARAM_EXP_MASK      GENMASK(31, 16)
> +#define   ACRY_RSA_PARAM_EXP_SHIFT     16
> +#define   ACRY_RSA_PARAM_MOD_MASK      GENMASK(15, 0)
> +#define   ACRY_RSA_PARAM_MOD_SHIFT     0
> +#define ACRY_RSA_INT_EN                0x3f8

The datasheet says this register is at address 0xf8.

> +#define   ACRY_RSA_INT_EN_RSA_READY    BIT(2)
> +#define   ACRY_RSA_INT_EN_RSA_CMPLT    BIT(1)
> +#define ACRY_RSA_INT_STS       0x3fc

The datasheet says this register is at address 0xfc.

> +#define   ACRY_RSA_INT_STS_RSA_READY   BIT(2)
> +#define   ACRY_RSA_INT_STS_RSA_CMPLT   BIT(1)
> +
> +/* misc. constant */
> +#define ACRY_ECC_MODE  2
> +#define ACRY_RSA_MODE  3
> +#define ACRY_CTX_BUFSZ 0x600
> +
> +struct aspeed_acry {
> +       phys_addr_t base;
> +       phys_addr_t sram_base; /* internal sram */
> +       struct clk clk;
> +};
> +
> +static int aspeed_acry_mod_exp(struct udevice *dev, const uint8_t *sig, uint32_t sig_len,
> +                              struct key_prop *prop, uint8_t *out)
> +{
> +       int i, j;
> +       u8 *ctx;
> +       u8 *ptr;
> +       u32 reg;
> +       struct aspeed_acry *acry = dev_get_priv(dev);
> +
> +       ctx = memalign(16, ACRY_CTX_BUFSZ);
> +       if (!ctx)
> +               return -ENOMEM;
> +
> +       memset(ctx, 0, ACRY_CTX_BUFSZ);
> +
> +       ptr = (u8 *)prop->public_exponent;
> +       for (i = prop->exp_len - 1, j = 0; i >= 0; --i) {
> +               ctx[j] = ptr[i];
> +               j++;
> +               j = (j % 16) ? j : j + 32;
> +       }
> +
> +       ptr = (u8 *)prop->modulus;
> +       for (i = (prop->num_bits >> 3) - 1, j = 0; i >= 0; --i) {
> +               ctx[j + 16] = ptr[i];
> +               j++;
> +               j = (j % 16) ? j : j + 32;
> +       }
> +
> +       ptr = (u8 *)sig;
> +       for (i = sig_len - 1, j = 0; i >= 0; --i) {
> +               ctx[j + 32] = ptr[i];
> +               j++;
> +               j = (j % 16) ? j : j + 32;
> +       }
> +
> +       writel((u32)ctx, acry->base + ACRY_DMA_DRAM_SADDR);
> +
> +       reg = (((prop->exp_len << 3) << ACRY_RSA_PARAM_EXP_SHIFT) & ACRY_RSA_PARAM_EXP_MASK) |
> +                 ((prop->num_bits << ACRY_RSA_PARAM_MOD_SHIFT) & ACRY_RSA_PARAM_MOD_MASK);
> +       writel(reg, acry->base + ACRY_RSA_PARAM);
> +
> +       reg = (ACRY_CTX_BUFSZ << ACRY_DMA_DMEM_TADDR_LEN_SHIFT) & ACRY_DMA_DMEM_TADDR_LEN_MASK;
> +       writel(reg, acry->base + ACRY_DMA_DMEM_TADDR);
> +
> +       reg = (ACRY_RSA_MODE << ACRY_CTRL3_ECC_RSA_MODE_SHIFT) & ACRY_CTRL3_ECC_RSA_MODE_MASK;
> +       writel(reg, acry->base + ACRY_CTRL3);
> +
> +       writel(ACRY_CTRL1_RSA_DMA | ACRY_CTRL1_RSA_START, acry->base + ACRY_CTRL1);
> +
> +       /* polling RSA status */
> +       while (1) {
> +               reg = readl(acry->base + ACRY_RSA_INT_STS);
> +               if ((reg & ACRY_RSA_INT_STS_RSA_READY) && (reg & ACRY_RSA_INT_STS_RSA_CMPLT)) {
> +                       writel(reg, ACRY_RSA_INT_STS);
> +                       break;
> +               }
> +               udelay(20);

This is an infinite loop.

Could you copy the HACE driver and use a timeout:

      u32 flag = ACRY_RSA_INT_STS_RSA_READY | ACRY_RSA_INT_STS_RSA_CMPLT;
      u32 val;

      return readl_poll_timeout(acry->base + ACRY_RSA_INT_STS, val,
(val & flag) == flag, timeout_us);


> +       }
> +
> +       /* grant SRAM access permission to CPU */
> +       writel(0x0, acry->base + ACRY_CTRL1);

This appears unrelated to granting access to the CPU. It's clearing
the setup config, which bits are required for SRAM access?

> +       writel(ACRY_CTRL3_SRAM_AHB_ACCESS, acry->base + ACRY_CTRL3);
> +       udelay(20);
> +
> +       for (i = (prop->num_bits / 8) - 1, j = 0; i >= 0; --i) {
> +               out[i] = readb(acry->sram_base + (j + 32));
> +               j++;
> +               j = (j % 16) ? j : j + 32;
> +       }
> +
> +       /* return SRAM access permission to ACRY */
> +       writel(0, acry->base + ACRY_CTRL3);
> +
> +       free(ctx);
> +
> +       return 0;
> +}
> +
> +static int aspeed_acry_probe(struct udevice *dev)
> +{
> +       struct aspeed_acry *acry = dev_get_priv(dev);
> +       int ret;
> +
> +       ret = clk_get_by_index(dev, 0, &acry->clk);
> +       if (ret < 0) {
> +               debug("Can't get clock for %s: %d\n", dev->name, ret);
> +               return ret;
> +       }
> +
> +       ret = clk_enable(&acry->clk);
> +       if (ret) {
> +               debug("Failed to enable acry clock (%d)\n", ret);
> +               return ret;
> +       }
> +
> +       acry->base = devfdt_get_addr_index(dev, 0);
> +       if (acry->base == FDT_ADDR_T_NONE) {
> +               debug("Failed to get acry base\n");
> +               return acry->base;
> +       }
> +
> +       acry->sram_base = devfdt_get_addr_index(dev, 1);
> +       if (acry->sram_base == FDT_ADDR_T_NONE) {
> +               debug("Failed to get acry SRAM base\n");
> +               return acry->sram_base;
> +       }
> +
> +       return ret;
> +}
> +
> +static int aspeed_acry_remove(struct udevice *dev)
> +{
> +       struct aspeed_acry *acry = dev_get_priv(dev);
> +
> +       clk_disable(&acry->clk);
> +
> +       return 0;
> +}
> +
> +static const struct mod_exp_ops aspeed_acry_ops = {
> +       .mod_exp = aspeed_acry_mod_exp,
> +};
> +
> +static const struct udevice_id aspeed_acry_ids[] = {
> +       { .compatible = "aspeed,ast2600-acry" },
> +       { }
> +};
> +
> +U_BOOT_DRIVER(aspeed_acry) = {
> +       .name = "aspeed_acry",
> +       .id = UCLASS_MOD_EXP,
> +       .of_match = aspeed_acry_ids,
> +       .probe = aspeed_acry_probe,
> +       .remove = aspeed_acry_remove,
> +       .priv_auto = sizeof(struct aspeed_acry),
> +       .ops = &aspeed_acry_ops,
> +       .flags = DM_FLAG_PRE_RELOC,
> +};
> diff --git a/lib/rsa/Kconfig b/lib/rsa/Kconfig
> index a90d67e5a8..4386c1dce4 100644
> --- a/lib/rsa/Kconfig
> +++ b/lib/rsa/Kconfig
> @@ -1,7 +1,8 @@
>  config RSA
>         bool "Use RSA Library"
>         select RSA_FREESCALE_EXP if FSL_CAAM && !ARCH_MX7 && !ARCH_MX6 && !ARCH_MX5
> -       select RSA_SOFTWARE_EXP if !RSA_FREESCALE_EXP
> +       select RSA_ASPEED_EXP if ASPEED_ACRY
> +       select RSA_SOFTWARE_EXP if !RSA_FREESCALE_EXP && !RSA_ASPEED_EXP

Can I suggest adding a hidden symbol HAS_HARDAWARE_EXP. Have the
ASPEED and Freescale drivers select this symbol.

config HAS_HARDWARE_EXP
        bool

then:

config RSA
        select RSA_SOFTWARE_EXP if !HAS_HARDWARE_EXP

>         help
>           RSA support. This enables the RSA algorithm used for FIT image
>           verification in U-Boot.
> @@ -61,4 +62,11 @@ config RSA_FREESCALE_EXP
>         Enables driver for RSA modular exponentiation using Freescale cryptographic
>         accelerator - CAAM.
>
> +config RSA_ASPEED_EXP
> +       bool "Enable RSA Modular Exponentiation with ASPEED crypto accelerator"
> +       depends on DM && ASPEED_ACRY
> +       help
> +       Enables driver for RSA modular exponentiation using ASPEED cryptographic
> +       accelerator - ACRY
> +
>  endif
> --
> 2.17.1
>


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