Re: [PATCH v2 18/18] firmware: arm_ffa: Allow multiple UUIDs per partition to register SRI callback

[Sudeep Holla <sudeep.holla@arm.com>]

On Fri, Jan 31, 2025 at 11:24:18AM +0000, Sudeep Holla wrote:
> A partition can implement multiple UUIDs and currently we successfully
> register each UUID service as a FF-A device. However when adding the
> same partition info to the XArray which tracks the SRI callbacks more
> than once, it fails.
> 
> In order to allow multiple UUIDs per partition to register SRI callbacks
> the partition information stored in the XArray needs to be extended to
> a listed list.
> 
> A function to remove the list of partition information in the XArray
> is not added as there are no users at the time. All the partitions are
> added at probe/initialisation and removed at cleanup stage.
> 
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
>  drivers/firmware/arm_ffa/driver.c | 157 ++++++++++++++++++++++++++++----------
>  1 file changed, 116 insertions(+), 41 deletions(-)
> 

[...]

>  static void ffa_partitions_cleanup(void)
>  {
> -	struct ffa_dev_part_info *info;
> +	struct ffa_dev_part_info *info, *tmp;
>  	unsigned long idx;
>  
>  	/* Clean up/free all registered devices */
>  	ffa_devices_unregister();
>  
>  	xa_for_each(&drv_info->partition_info, idx, info) {
> +		struct list_head *phead = (struct list_head *)idx;
> +
>  		xa_erase(&drv_info->partition_info, idx);
> -		kfree(info);
> +		list_for_each_entry_safe(info, tmp, phead, node) {
> +			list_del(&info->node);
> +			kfree(info);
> +		}
> +		kfree(phead);

Issue was discovered when testing it as module(that's when cleanup
gets executed). It is now fixed here[1] with the below patch.

Regards,
Sudeep

[1] https://git.kernel.org/sudeep.holla/l/ffa_updates

-->8

diff --git c/drivers/firmware/arm_ffa/driver.c w/drivers/firmware/arm_ffa/driver.c
index 3c49ab3fe118..c184a220147f 100644
--- c/drivers/firmware/arm_ffa/driver.c
+++ w/drivers/firmware/arm_ffa/driver.c
@@ -1644,14 +1644,14 @@ static int ffa_setup_host_partition(int vm_id)
 
 static void ffa_partitions_cleanup(void)
 {
-       struct ffa_dev_part_info *info, *tmp;
+       struct list_head *phead;
        unsigned long idx;
 
        /* Clean up/free all registered devices */
        ffa_devices_unregister();
 
-       xa_for_each(&drv_info->partition_info, idx, info) {
-               struct list_head *phead = (struct list_head *)idx;
+       xa_for_each(&drv_info->partition_info, idx, phead) {
+               struct ffa_dev_part_info *info, *tmp;
 
                xa_erase(&drv_info->partition_info, idx);
                list_for_each_entry_safe(info, tmp, phead, node) {