[PATCH] tee: optee: sync cache on pre-reloc OP-TEE invocation

[Jens Wiklander]

On Wed, May 12, 2021 at 5:08 PM Etienne Carriere
<etienne.carriere at linaro.org> wrote:
>
> This change ensures both U-Boot and OP-TEE see the same content
> from shared memory when OP-TEE is invoked prior U-Boot relocation.
>
> This change is required since U-Boot may execute with data cahce off
> while OP-TEE always enables cache on memory shared with U-Boot.
>
> Signed-off-by: Etienne Carriere <etienne.carriere at linaro.org>
> ---
>  drivers/tee/optee/core.c | 20 +++++++++++++++++++-
>  drivers/tee/tee-uclass.c | 18 +++++++++++++++++-
>  include/tee.h            |  6 ++++++
>  3 files changed, 42 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> index 73dbb22ba0..120d315813 100644
> --- a/drivers/tee/optee/core.c
> +++ b/drivers/tee/optee/core.c
> @@ -1,9 +1,10 @@
>  // SPDX-License-Identifier: GPL-2.0+
>  /*
> - * Copyright (c) 2018 Linaro Limited
> + * Copyright (c) 2018-2020 Linaro Limited
>   */
>
>  #include <common.h>
> +#include <cpu_func.h>
>  #include <dm.h>
>  #include <dm/device_compat.h>
>  #include <log.h>
> @@ -295,6 +296,15 @@ static u32 call_err_to_res(u32 call_err)
>         }
>  }
>
> +static void flush_shm_dcache(struct udevice *dev, struct optee_msg_arg *arg)
> +{
> +       flush_dcache_range(rounddown((ulong)arg, CONFIG_SYS_CACHELINE_SIZE),
> +                          roundup((ulong)arg + sizeof(*arg),
> +                                  CONFIG_SYS_CACHELINE_SIZE));

Please use the OPTEE_MSG_GET_ARG_SIZE() macro to calculate the size of
the argument struct.

Cheers,
Jens

> +
> +       tee_flush_all_shm_dcache(dev);
> +}
> +
>  static u32 do_call_with_arg(struct udevice *dev, struct optee_msg_arg *arg)
>  {
>         struct optee_pdata *pdata = dev_get_plat(dev);
> @@ -305,9 +315,17 @@ static u32 do_call_with_arg(struct udevice *dev, struct optee_msg_arg *arg)
>         while (true) {
>                 struct arm_smccc_res res;
>
> +               /* If cache are off from U-Boot, sync the cache shared with OP-TEE */
> +               if (!dcache_status())
> +                       flush_shm_dcache(dev, arg);
> +
>                 pdata->invoke_fn(param.a0, param.a1, param.a2, param.a3,
>                                  param.a4, param.a5, param.a6, param.a7, &res);
>
> +               /* If cache are off from U-Boot, sync the cache shared with OP-TEE */
> +               if (!dcache_status())
> +                       flush_shm_dcache(dev, arg);
> +
>                 free(page_list);
>                 page_list = NULL;
>
> diff --git a/drivers/tee/tee-uclass.c b/drivers/tee/tee-uclass.c
> index 2cc6b6c407..81fcd4e801 100644
> --- a/drivers/tee/tee-uclass.c
> +++ b/drivers/tee/tee-uclass.c
> @@ -1,9 +1,10 @@
>  // SPDX-License-Identifier: GPL-2.0+
>  /*
> - * Copyright (c) 2018 Linaro Limited
> + * Copyright (c) 2018-2020 Linaro Limited
>   */
>
>  #include <common.h>
> +#include <cpu_func.h>
>  #include <dm.h>
>  #include <log.h>
>  #include <malloc.h>
> @@ -233,3 +234,18 @@ void tee_optee_ta_uuid_to_octets(u8 d[TEE_UUID_LEN],
>         d[7] = s->time_hi_and_version;
>         memcpy(d + 8, s->clock_seq_and_node, sizeof(s->clock_seq_and_node));
>  }
> +
> +void tee_flush_all_shm_dcache(struct udevice *dev)
> +{
> +       struct tee_uclass_priv *priv = dev_get_uclass_priv(dev);
> +       struct tee_shm *s;
> +
> +       list_for_each_entry(s, &priv->list_shm, link) {
> +               ulong start = rounddown((ulong)s->addr,
> +                                       CONFIG_SYS_CACHELINE_SIZE);
> +               ulong end = roundup((ulong)s->addr + s->size,
> +                                   CONFIG_SYS_CACHELINE_SIZE);
> +
> +               flush_dcache_range(start, end);
> +       }
> +}
> diff --git a/include/tee.h b/include/tee.h
> index 99367b258e..2ef29bfc8f 100644
> --- a/include/tee.h
> +++ b/include/tee.h
> @@ -377,4 +377,10 @@ void tee_optee_ta_uuid_from_octets(struct tee_optee_ta_uuid *d,
>  void tee_optee_ta_uuid_to_octets(u8 d[TEE_UUID_LEN],
>                                  const struct tee_optee_ta_uuid *s);
>
> +/**
> + * tee_flush_all_shm_dcache() - Flush data cache for all shared memories
> + * @dev:       The TEE device
> + */
> +void tee_flush_all_shm_dcache(struct udevice *dev);
> +
>  #endif /* __TEE_H */
> --
> 2.17.1
>