[RFC PATCH v2 1/2] optee: obtain emmc rpmb info from dt

[Jens Wiklander]

Hi Igor,

On Sun, Jan 24, 2021 at 11:39:45AM +0200, Igor Opaniuk wrote:
> From: Igor Opaniuk <igor.opaniuk at foundries.io>
> 
> Add support for rpmb-dev property in optee node.
> Prioritize that provided eMMC info from DT for RPMB operations over
> the one provided by OP-TEE OS core in RPC calls.
> 
> Signed-off-by: Igor Opaniuk <igor.opaniuk at foundries.io>
> ---
> 
> Changes in v2:
> - Return NULL instead of ERR_PTR(-ENXIO) in get_rpmb_dev in case there
>   is no rpmb-dev property or somemithing went wrong
> 
>  drivers/tee/optee/core.c          | 33 +++++++++++++++++
>  drivers/tee/optee/optee_private.h |  2 +-
>  drivers/tee/optee/rpmb.c          | 60 ++++++++++++++++++-------------
>  3 files changed, 70 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> index b898c32edc..828ab9b00a 100644
> --- a/drivers/tee/optee/core.c
> +++ b/drivers/tee/optee/core.c
> @@ -12,6 +12,7 @@
>  #include <linux/arm-smccc.h>
>  #include <linux/err.h>
>  #include <linux/io.h>
> +#include <mmc.h>
>  
>  #include "optee_smc.h"
>  #include "optee_msg.h"
> @@ -607,14 +608,46 @@ static optee_invoke_fn *get_invoke_func(struct udevice *dev)
>  	return ERR_PTR(-EINVAL);
>  }
>  
> +static struct mmc *get_rpmb_dev(struct udevice *dev)
> +{
> +	struct udevice *mmc_dev;
> +	const fdt32_t *phandle_p;
> +	u32 phandle;
> +	int ret = 0;
> +
> +	debug("optee: looking for rpmb device in DT.\n");
> +
> +	phandle_p  = ofnode_get_property(dev_ofnode(dev),
> +					 "rpmb-dev", NULL);
> +	if (!phandle_p) {
> +		debug("optee: missing \"rpmb-dev\" property\n");

With this we'll complain in the log each time "rpmb-dev" isn't found
even when OP-TEE isn't configured to use RPMB. This might cause some
confusion.

Cheers,
Jens

> +		return NULL;
> +	}
> +
> +	phandle = fdt32_to_cpu(*phandle_p);
> +
> +	ret = uclass_get_device_by_phandle_id(UCLASS_MMC, phandle, &mmc_dev);
> +	if (ret) {
> +		printf("optee: invalid phandle value in \"rpmb-dev\".\n");
> +		return NULL;
> +	}
> +
> +	debug("optee: using phandle %d from \"rpmd-dev\" property.\n",
> +	      phandle);
> +	return mmc_get_mmc_dev(mmc_dev);
> +}
> +
>  static int optee_of_to_plat(struct udevice *dev)
>  {
>  	struct optee_pdata *pdata = dev_get_plat(dev);
> +	struct optee_private *priv = dev_get_priv(dev);
>  
>  	pdata->invoke_fn = get_invoke_func(dev);
>  	if (IS_ERR(pdata->invoke_fn))
>  		return PTR_ERR(pdata->invoke_fn);
>  
> +	priv->rpmb_mmc = get_rpmb_dev(dev);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index 1f07a27ee4..8e5a280622 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -19,8 +19,8 @@
>   */
>  struct optee_private {
>  	struct mmc *rpmb_mmc;
> -	int rpmb_dev_id;
>  	int rpmb_original_part;
> +	bool rpmb_inited;
>  };
>  
>  struct optee_msg_arg;
> diff --git a/drivers/tee/optee/rpmb.c b/drivers/tee/optee/rpmb.c
> index 0804fc963c..0137c44be1 100644
> --- a/drivers/tee/optee/rpmb.c
> +++ b/drivers/tee/optee/rpmb.c
> @@ -45,55 +45,67 @@ static void release_mmc(struct optee_private *priv)
>  {
>  	int rc;
>  
> -	if (!priv->rpmb_mmc)
> +	if (!priv->rpmb_mmc || !priv->rpmb_inited)
>  		return;
>  
> -	rc = blk_select_hwpart_devnum(IF_TYPE_MMC, priv->rpmb_dev_id,
> -				      priv->rpmb_original_part);
> +	rc = mmc_switch_part(priv->rpmb_mmc, priv->rpmb_original_part);
>  	if (rc)
>  		debug("%s: blk_select_hwpart_devnum() failed: %d\n",
>  		      __func__, rc);
>  
> -	priv->rpmb_mmc = NULL;
> +	priv->rpmb_inited = false;
> +}
> +
> +static int check_mmc(struct mmc *mmc)
> +{
> +	if (!mmc) {
> +		debug("Cannot find RPMB device\n");
> +		return -ENODEV;
> +	}
> +	if (!(mmc->version & MMC_VERSION_MMC)) {
> +		debug("Device id is not an eMMC device\n");
> +		return -ENODEV;
> +	}
> +	if (mmc->version < MMC_VERSION_4_41) {
> +		debug("RPMB is not supported before version 4.41\n");
> +		return -ENODEV;
> +	}
> +
> +	return 0;
>  }
>  
>  static struct mmc *get_mmc(struct optee_private *priv, int dev_id)
>  {
> -	struct mmc *mmc;
>  	int rc;
>  
> -	if (priv->rpmb_mmc && priv->rpmb_dev_id == dev_id)
> +	if (priv->rpmb_mmc && priv->rpmb_inited)
>  		return priv->rpmb_mmc;
>  
>  	release_mmc(priv);
>  
> -	mmc = find_mmc_device(dev_id);
> -	if (!mmc) {
> -		debug("Cannot find RPMB device\n");
> -		return NULL;
> -	}
> -	if (!(mmc->version & MMC_VERSION_MMC)) {
> -		debug("Device id %d is not an eMMC device\n", dev_id);
> -		return NULL;
> -	}
> -	if (mmc->version < MMC_VERSION_4_41) {
> -		debug("Device id %d: RPMB not supported before version 4.41\n",
> -		      dev_id);
> +	/*
> +	 * Check if priv->rpmb_mmc was already set from DT node,
> +	 * otherwise use dev_id provided by OP-TEE OS
> +	 * and find mmc device by its dev_id
> +	 */
> +	if (!priv->rpmb_mmc)
> +		priv->rpmb_mmc = find_mmc_device(dev_id);
> +
> +	rc = check_mmc(priv->rpmb_mmc);
> +	if (rc)
>  		return NULL;
> -	}
>  
> -	priv->rpmb_original_part = mmc_get_blk_desc(mmc)->hwpart;
> +	priv->rpmb_original_part = mmc_get_blk_desc(priv->rpmb_mmc)->hwpart;
>  
> -	rc = blk_select_hwpart_devnum(IF_TYPE_MMC, dev_id, MMC_PART_RPMB);
> +	rc = mmc_switch_part(priv->rpmb_mmc, MMC_PART_RPMB);
>  	if (rc) {
>  		debug("Device id %d: cannot select RPMB partition: %d\n",
>  		      dev_id, rc);
>  		return NULL;
>  	}
>  
> -	priv->rpmb_mmc = mmc;
> -	priv->rpmb_dev_id = dev_id;
> -	return mmc;
> +	priv->rpmb_inited = true;
> +	return priv->rpmb_mmc;
>  }
>  
>  static u32 rpmb_get_dev_info(u16 dev_id, struct rpmb_dev_info *info)
> -- 
> 2.25.1
>