linux-kernel - Re: [RESEND,PATCH 1/2] firmware: qcom: scm: Add SDI disable support

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Date:   Thu, 18 May 2023 19:55:16 +0530
From:   Mukesh Ojha <quic_mojha@...cinc.com>
To:     Robert Marko <robimarko@...il.com>, <agross@...nel.org>,
        <andersson@...nel.org>, <konrad.dybcio@...aro.org>,
        <linux-arm-msm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <srichara@...cinc.com>
Subject: Re: [RESEND,PATCH 1/2] firmware: qcom: scm: Add SDI disable support



On 5/18/2023 7:32 PM, Robert Marko wrote:
> Some SoC-s like IPQ5018 require SDI(Secure Debug Image) to be disabled
> before trying to reboot, otherwise board will just hang after reboot has
> been issued via PSCI.
> 
> So, provide a call to SCM that allows disabling it.
> 
> Signed-off-by: Robert Marko <robimarko@...il.com>

This scm call support indeed needed for reboot cases, but i am not sure
about target specific check in the later patch.

Acked-by: Mukesh Ojha <quic_mojha@...cinc.com>

-- Mukesh

> ---
>   drivers/firmware/qcom_scm.c | 23 +++++++++++++++++++++++
>   drivers/firmware/qcom_scm.h |  1 +
>   2 files changed, 24 insertions(+)
> 
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index fde33acd46b7..bdc9324d4e62 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -407,6 +407,29 @@ int qcom_scm_set_remote_state(u32 state, u32 id)
>   }
>   EXPORT_SYMBOL(qcom_scm_set_remote_state);
>   
> +static int qcom_scm_disable_sdi(void)
> +{
> +	int ret;
> +	struct qcom_scm_desc desc = {
> +		.svc = QCOM_SCM_SVC_BOOT,
> +		.cmd = QCOM_SCM_BOOT_SDI_CONFIG,
> +		.args[0] = 1, /* Disable watchdog debug */
> +		.args[1] = 0, /* Disable SDI */
> +		.arginfo = QCOM_SCM_ARGS(2),
> +		.owner = ARM_SMCCC_OWNER_SIP,
> +	};
> +	struct qcom_scm_res res;
> +
> +	ret = qcom_scm_clk_enable();
> +	if (ret)
> +		return ret;
> +	ret = qcom_scm_call(__scm->dev, &desc, &res);
> +
> +	qcom_scm_clk_disable();
> +
> +	return ret ? : res.result[0];
> +}
> +
>   static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
>   {
>   	struct qcom_scm_desc desc = {
> diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
> index e6e512bd57d1..7b68fa820495 100644
> --- a/drivers/firmware/qcom_scm.h
> +++ b/drivers/firmware/qcom_scm.h
> @@ -80,6 +80,7 @@ extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,
>   #define QCOM_SCM_SVC_BOOT		0x01
>   #define QCOM_SCM_BOOT_SET_ADDR		0x01
>   #define QCOM_SCM_BOOT_TERMINATE_PC	0x02
> +#define QCOM_SCM_BOOT_SDI_CONFIG	0x09
>   #define QCOM_SCM_BOOT_SET_DLOAD_MODE	0x10
>   #define QCOM_SCM_BOOT_SET_ADDR_MC	0x11
>   #define QCOM_SCM_BOOT_SET_REMOTE_STATE	0x0a