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

ChiaWei Wang chiawei_wang at aspeedtech.com
Thu Oct 21 04:02:02 CEST 2021


> From: Joel Stanley <joel at jms.id.au>
> Sent: Thursday, October 21, 2021 8:25 AM
> 
> 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

Thanks for pointing out the typo. It will be fixed in the next revision

Regards,
Chiawei

> 
> > 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
> >


More information about the U-Boot mailing list