[PATCH 2/2] tpm2: Add a TPMv2 MMIO TIS driver

Simon Glass sjg at chromium.org
Sun Jul 11 02:00:59 CEST 2021


Hi Ilias,

On Wed, 7 Jul 2021 at 10:26, Ilias Apalodimas
<ilias.apalodimas at linaro.org> wrote:
>
> Add support for devices that expose a TPMv2 though MMIO.
> Apart from those devices, we can use the driver in our QEMU setups and
> test TPM related code which is difficult to achieve using the sandbox
> driver (e.g test the EFI TCG2 protocol).
>
> It's worth noting that a previous patch added TPMv2 TIS core functions,
> which the current driver is consuming.
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> ---
> Changes since v1:
> - split off the tis core code into a different file
>  drivers/tpm/Kconfig         |   9 +++
>  drivers/tpm/Makefile        |   1 +
>  drivers/tpm/tpm2_tis_mmio.c | 156 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 166 insertions(+)
>  create mode 100644 drivers/tpm/tpm2_tis_mmio.c

Looks good to me

>
> diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
> index 9eebab5cfd90..406ee8716e1e 100644
> --- a/drivers/tpm/Kconfig
> +++ b/drivers/tpm/Kconfig
> @@ -161,6 +161,15 @@ config TPM2_FTPM_TEE
>         help
>           This driver supports firmware TPM running in TEE.
>
> +config TPM2_MMIO
> +       bool "MMIO based TPM2 Interface"
> +       depends on TPM_V2
> +       help
> +         This driver supports firmware TPM2.0 MMIO interface.
> +         The usual TPM operations and the 'tpm' command can be used to talk
> +         to the device using the standard TPM Interface Specification (TIS)
> +         protocol.
> +
>  endif # TPM_V2
>
>  endmenu
> diff --git a/drivers/tpm/Makefile b/drivers/tpm/Makefile
> index f64d20067f88..1065c1874f58 100644
> --- a/drivers/tpm/Makefile
> +++ b/drivers/tpm/Makefile
> @@ -14,3 +14,4 @@ obj-$(CONFIG_$(SPL_TPL_)TPM2_CR50_I2C) += cr50_i2c.o
>  obj-$(CONFIG_TPM2_TIS_SANDBOX) += tpm2_tis_sandbox.o
>  obj-$(CONFIG_TPM2_TIS_SPI) += tpm2_tis_spi.o
>  obj-$(CONFIG_TPM2_FTPM_TEE) += tpm2_ftpm_tee.o
> +obj-$(CONFIG_TPM2_MMIO) += tpm2_tis_core.o tpm2_tis_mmio.o
> diff --git a/drivers/tpm/tpm2_tis_mmio.c b/drivers/tpm/tpm2_tis_mmio.c
> new file mode 100644
> index 000000000000..2183a2807162
> --- /dev/null
> +++ b/drivers/tpm/tpm2_tis_mmio.c
> @@ -0,0 +1,156 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * driver for mmio TCG/TIS TPM (trusted platform module).
> + *
> + * Specifications at www.trustedcomputinggroup.org
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <log.h>
> +#include <tpm-v2.h>
> +#include <linux/bitops.h>
> +#include <linux/compiler.h>
> +#include <linux/delay.h>
> +#include <linux/errno.h>
> +#include <linux/types.h>
> +#include <linux/io.h>
> +#include <linux/unaligned/be_byteshift.h>
> +#include "tpm_tis.h"
> +#include "tpm_internal.h"
> +
> +struct tpm_tis_chip_data {
> +       unsigned int pcr_count;
> +       unsigned int pcr_select_min;
> +       unsigned int time_before_first_cmd_ms;
> +       void __iomem *iobase;
> +};

comments

> +
> +static int mmio_read_bytes(struct udevice *udev, u32 addr, u16 len,
> +                          u8 *result)
> +{
> +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> +
> +       while (len--)
> +               *result++ = ioread8(drv_data->iobase + addr);

We normally put a blank line before the final return

> +       return 0;
> +}
> +
> +static int mmio_write_bytes(struct udevice *udev, u32 addr, u16 len,
> +                           const u8 *value)
> +{
> +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> +
> +       while (len--)
> +               iowrite8(*value++, drv_data->iobase + addr);
> +       return 0;
> +}
> +
> +static int mmio_read16(struct udevice *udev, u32 addr, u16 *result)
> +{
> +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> +
> +       *result = ioread16(drv_data->iobase + addr);
> +       return 0;
> +}
> +
> +static int mmio_read32(struct udevice *udev, u32 addr, u32 *result)
> +{
> +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> +
> +       *result = ioread32(drv_data->iobase + addr);
> +       return 0;
> +}
> +
> +static int mmio_write32(struct udevice *udev, u32 addr, u32 value)
> +{
> +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> +
> +       iowrite32(value, drv_data->iobase + addr);
> +       return 0;
> +}
> +
> +static struct tpm_tis_phy_ops phy_ops = {

Should be a uclass interface.

> +       .read_bytes = mmio_read_bytes,
> +       .write_bytes = mmio_write_bytes,
> +       .read16 = mmio_read16,
> +       .read32 = mmio_read32,
> +       .write32 = mmio_write32,
> +};
> +
> +static int tpm_tis_probe(struct udevice *udev)
> +{
> +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> +       struct tpm_chip_priv *priv = dev_get_uclass_priv(udev);
> +       int ret = 0;
> +       fdt_addr_t ioaddr;
> +       u64 sz;
> +
> +       ioaddr = dev_read_addr(udev);
> +       if (ioaddr == FDT_ADDR_T_NONE)
> +               return -EINVAL;

consider this for easier debugging:

   return log_msg_ret("ioaddr", -EINVAL);

> +
> +       ret = dev_read_u64(udev, "reg", &sz);
> +       if (ret)
> +               return -EINVAL;
> +
> +       drv_data->iobase = ioremap(ioaddr, sz);
> +       log_info("Remapped TPM2 base: 0x%llx size: 0x%llx\n", ioaddr, sz);

log_debug() I think?

> +       tpm_tis_ops_register(udev, &phy_ops);
> +       ret = tpm_tis_init(udev);
> +       if (ret)
> +               goto iounmap;
> +
> +       priv->pcr_count = drv_data->pcr_count;
> +       priv->pcr_select_min = drv_data->pcr_select_min;
> +       /*
> +        * Although the driver probably works with a TPMv1 our Kconfig
> +        * limits the driver to TPMv2 only
> +        */
> +       priv->version = TPM_V2;
> +
> +       return ret;
> +iounmap:
> +       iounmap(drv_data->iobase);
> +       return -EINVAL;
> +}
> +
> +static int tpm_tis_remove(struct udevice *udev)
> +{
> +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> +
> +       iounmap(drv_data->iobase);
> +       return tpm_tis_cleanup(udev);
> +}
> +
> +static const struct tpm_ops tpm_tis_ops = {
> +       .open           = tpm_tis_open,
> +       .close          = tpm_tis_close,
> +       .get_desc       = tpm_tis_get_desc,
> +       .send           = tpm_tis_send,
> +       .recv           = tpm_tis_recv,
> +       .cleanup        = tpm_tis_cleanup,
> +};
> +
> +static const struct tpm_tis_chip_data tpm_tis_std_chip_data = {
> +       .pcr_count = 24,
> +       .pcr_select_min = 3,
> +};
> +
> +static const struct udevice_id tpm_tis_ids[] = {
> +       {
> +               .compatible = "tcg,tpm-tis-mmio",
> +               .data = (ulong)&tpm_tis_std_chip_data,
> +       },
> +       { }
> +};
> +
> +U_BOOT_DRIVER(tpm_tis_mmio) = {
> +       .name   = "tpm_tis_mmio",
> +       .id     = UCLASS_TPM,
> +       .of_match = tpm_tis_ids,
> +       .ops    = &tpm_tis_ops,
> +       .probe  = tpm_tis_probe,
> +       .remove = tpm_tis_remove,
> +       .priv_auto      = sizeof(struct tpm_chip),
> +};
> --
> 2.32.0.rc0
>

Regards,
Simon


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