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Date:   Wed, 4 Oct 2023 11:11:54 +0200
From:   Jens Wiklander <jens.wiklander@linaro.org>
To:     Sudeep Holla <sudeep.holla@arm.com>
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Marc Bonnici <marc.bonnici@arm.com>,
        Coboy Chen <coboy.chen@mediatek.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Olivier Deprez <olivier.deprez@arm.com>
Subject: Re: [PATCH v3 03/17] firmware: arm_ffa: Implement the notification
 bind and unbind interface
Message-ID: <20231004091154.GB1091193@rayden>
References: <20230929-ffa_v1-1_notif-v3-0-c8e4f15190c8@arm.com>
 <20230929-ffa_v1-1_notif-v3-3-c8e4f15190c8@arm.com>
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On Fri, Sep 29, 2023 at 04:02:52PM +0100, Sudeep Holla wrote:
> A receiver endpoint must bind a notification to any sender endpoint
> before the latter can signal the notification to the former. The receiver
> assigns one or more doorbells to a specific sender. Only the sender can
> ring these doorbells.
> 
> A receiver uses the FFA_NOTIFICATION_BIND interface to bind one or more
> notifications to the sender. A receiver un-binds a notification from a
> sender endpoint to stop the notification from being signaled. It uses
> the FFA_NOTIFICATION_UNBIND interface to do this.
> 
> Allow the FF-A driver to be able to bind and unbind a given notification
> ID to a specific partition ID. This will be used to register and
> unregister notification callbacks from the FF-A client drivers.
> 
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
>  drivers/firmware/arm_ffa/driver.c | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
> index efa4e7fb15e3..26bf9c4e3b5f 100644
> --- a/drivers/firmware/arm_ffa/driver.c
> +++ b/drivers/firmware/arm_ffa/driver.c
> @@ -587,6 +587,35 @@ static int ffa_notification_bitmap_destroy(void)
>  	return 0;
>  }
>  
> +#define NOTIFICATION_LOW_MASK		GENMASK(31, 0)
> +#define NOTIFICATION_HIGH_MASK		GENMASK(63, 32)
> +#define NOTIFICATION_BITMAP_HIGH(x)	\
> +		((u32)(FIELD_GET(NOTIFICATION_HIGH_MASK, (x))))
> +#define NOTIFICATION_BITMAP_LOW(x)	\
> +		((u32)(FIELD_GET(NOTIFICATION_LOW_MASK, (x))))
> +
> +static int ffa_notification_bind_common(u16 dst_id, u64 bitmap,
> +					u32 flags, bool is_bind)
> +{
> +	ffa_value_t ret;
> +	u32 func, src_dst_ids = PACK_TARGET_INFO(dst_id, drv_info->vm_id);

dst_id and drv_info->vm_id should be swapped.

Thanks,
Jens

> +
> +	func = is_bind ? FFA_NOTIFICATION_BIND : FFA_NOTIFICATION_UNBIND;
> +
> +	invoke_ffa_fn((ffa_value_t){
> +		  .a0 = func, .a1 = src_dst_ids, .a2 = flags,
> +		  .a3 = NOTIFICATION_BITMAP_LOW(bitmap),
> +		  .a4 = NOTIFICATION_BITMAP_HIGH(bitmap),
> +		  }, &ret);
> +
> +	if (ret.a0 == FFA_ERROR)
> +		return ffa_to_linux_errno((int)ret.a2);
> +	else if (ret.a0 != FFA_SUCCESS)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
>  static void ffa_set_up_mem_ops_native_flag(void)
>  {
>  	if (!ffa_features(FFA_FN_NATIVE(MEM_LEND), 0, NULL, NULL) ||
> 
> -- 
> 2.42.0
>