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Date:   Tue, 10 Oct 2023 17:49:50 -0500
From:   Andrew Halaney <ahalaney@redhat.com>
To:     Bartosz Golaszewski <brgl@bgdev.pl>
Cc:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Elliot Berman <quic_eberman@quicinc.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Guru Das Srinagesh <quic_gurus@quicinc.com>,
        Maximilian Luz <luzmaximilian@gmail.com>,
        Alex Elder <elder@linaro.org>,
        Srini Kandagatla <srinivas.kandagatla@linaro.org>,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, kernel@quicinc.com,
        Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: Re: [PATCH v3 11/15] firmware: qcom: qseecom: convert to using the
 TZ allocator
Message-ID: <y5otsuzhc27xeay6js4nkqss2bo5bsmygwdjuhqpdzce4yffxk@gkkh522s5e3b>
References: <20231009153427.20951-1-brgl@bgdev.pl>
 <20231009153427.20951-12-brgl@bgdev.pl>
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On Mon, Oct 09, 2023 at 05:34:23PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> 
> Drop the DMA mapping operations from qcom_scm_qseecom_app_send() and
> convert all users of it in the qseecom module to using the TZ allocator
> for creating SCM call buffers. Together with using the cleanup macros,
> it has the added benefit of a significant code shrink. As this is
> largely a module separate from the SCM driver, let's use a separate
> memory pool.
> 
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

<snip>

> @@ -567,20 +529,14 @@ static efi_status_t qsee_uefi_get_next_variable(struct qcuefi_client *qcuefi,
>  		return EFI_INVALID_PARAMETER;
>  
>  	status = qcom_qseecom_app_send(qcuefi->client, req_data, req_size, rsp_data, rsp_size);
> -	if (status) {
> -		efi_status = EFI_DEVICE_ERROR;
> -		goto out_free;
> -	}
> +	if (status)
> +		return EFI_DEVICE_ERROR;
>  
> -	if (rsp_data->command_id != QSEE_CMD_UEFI_GET_NEXT_VARIABLE) {
> -		efi_status = EFI_DEVICE_ERROR;
> -		goto out_free;
> -	}
> +	if (rsp_data->command_id != QSEE_CMD_UEFI_GET_NEXT_VARIABLE)
> +		return EFI_DEVICE_ERROR;
>  
> -	if (rsp_data->length < sizeof(*rsp_data)) {
> -		efi_status = EFI_DEVICE_ERROR;
> -		goto out_free;
> -	}
> +	if (rsp_data->length < sizeof(*rsp_data))
> +		return EFI_DEVICE_ERROR;
>  
>  	if (rsp_data->status) {
>  		dev_dbg(qcuefi_dev(qcuefi), "%s: uefisecapp error: 0x%x\n",
> @@ -595,77 +551,59 @@ static efi_status_t qsee_uefi_get_next_variable(struct qcuefi_client *qcuefi,
>  		if (efi_status == EFI_BUFFER_TOO_SMALL)
>  			*name_size = rsp_data->name_size;
>  
> -		goto out_free;
> +		return efi_status;
>  	}
>  
> -	if (rsp_data->length > rsp_size) {
> -		efi_status = EFI_DEVICE_ERROR;
> -		goto out_free;
> -	}
> +	if (rsp_data->length > rsp_size)
> +		return EFI_DEVICE_ERROR;
>  
> -	if (rsp_data->name_offset + rsp_data->name_size > rsp_data->length) {
> -		efi_status = EFI_DEVICE_ERROR;
> -		goto out_free;
> -	}
> +	if (rsp_data->name_offset + rsp_data->name_size > rsp_data->length)
> +		return EFI_DEVICE_ERROR;
>  
> -	if (rsp_data->guid_offset + rsp_data->guid_size > rsp_data->length) {
> -		efi_status = EFI_DEVICE_ERROR;
> -		goto out_free;
> -	}
> +	if (rsp_data->guid_offset + rsp_data->guid_size > rsp_data->length)
> +		return EFI_DEVICE_ERROR;
>  
>  	if (rsp_data->name_size > *name_size) {
>  		*name_size = rsp_data->name_size;
> -		efi_status = EFI_BUFFER_TOO_SMALL;
> -		goto out_free;
> +		return EFI_BUFFER_TOO_SMALL;
>  	}
>  
> -	if (rsp_data->guid_size != sizeof(*guid)) {
> -		efi_status = EFI_DEVICE_ERROR;
> -		goto out_free;
> -	}
> +	if (rsp_data->guid_size != sizeof(*guid))
> +		return EFI_DEVICE_ERROR;
>  
>  	memcpy(guid, ((void *)rsp_data) + rsp_data->guid_offset, rsp_data->guid_size);
>  	status = ucs2_strscpy(name, ((void *)rsp_data) + rsp_data->name_offset,
>  			      rsp_data->name_size / sizeof(*name));
>  	*name_size = rsp_data->name_size;
>  
> -	if (status < 0) {
> +	if (status < 0)
>  		/*
>  		 * Return EFI_DEVICE_ERROR here because the buffer size should
>  		 * have already been validated above, causing this function to
>  		 * bail with EFI_BUFFER_TOO_SMALL.
>  		 */
>  		return EFI_DEVICE_ERROR;
> -	}

Personally (no idea what the actual style guide says) leaving braces
around the multiline if statement would be nice.... that being said,
that's my opinion :)

<snip>
> @@ -704,12 +635,7 @@ static efi_status_t qsee_uefi_query_variable_info(struct qcuefi_client *qcuefi,
>  	if (max_variable_size)
>  		*max_variable_size = rsp_data->max_variable_size;
>  
> -out_free:
> -	kfree(rsp_data);
> -out_free_req:
> -	kfree(req_data);
> -out:
> -	return efi_status;
> +	return EFI_SUCCESS;
>  }
>  
>  /* -- Global efivar interface. ---------------------------------------------- */
> @@ -838,6 +764,10 @@ static int qcom_uefisecapp_probe(struct auxiliary_device *aux_dev,
>  	if (status)
>  		qcuefi_set_reference(NULL);
>  
> +	qcuefi->mempool = devm_qcom_tzmem_pool_new(&aux_dev->dev, SZ_256K);

Any particular reason for this size? Just curious, it was (one) of the
reasons I had not marked patch 4 yet (it looks good, but I wanted to get
through the series to digest the Kconfig as well).

Reviewed-by: Andrew Halaney <ahalaney@redhat.com>