firmware: arm_ffa: Use xa_insert() and check for result

JIRA: https://issues.redhat.com/browse/RHEL-102691

commit ace760d
Author: Cristian Marussi <cristian.marussi@arm.com>
Date: Mon, 8 Jan 2024 12:34:15 +0000

    While adding new partitions descriptors to the XArray the outcome of the
    stores should be checked and, in particular, it has also to be ensured
    that an existing entry with the same index was not already present, since
    partitions IDs are expected to be unique.

    Use xa_insert() instead of xa_store() since it returns -EBUSY when the
    index is already in use and log an error when that happens.

    Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
    Link: https://lore.kernel.org/r/20240108-ffa_fixes_6-8-v1-5-75bf7035bc50@arm.com
    Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Signed-off-by: Marcin Juszkiewicz <mjuszkiewicz@redhat.com>

Author: hrw

drivers/firmware/arm_ffa/driver.c

@@ -1197,7 +1197,7 @@ void ffa_device_match_uuid(struct ffa_device *ffa_dev, const uuid_t *uuid)
 
 static void ffa_setup_partitions(void)
 {
-	int count, idx;
+	int count, idx, ret;
 	uuid_t uuid;
 	struct ffa_device *ffa_dev;
 	struct ffa_dev_part_info *info;
@@ -1236,7 +1236,14 @@ static void ffa_setup_partitions(void)
 			continue;
 		}
 		rwlock_init(&info->rw_lock);
-		xa_store(&drv_info->partition_info, tpbuf->id, info, GFP_KERNEL);
+		ret = xa_insert(&drv_info->partition_info, tpbuf->id,
+				info, GFP_KERNEL);
+		if (ret) {
+			pr_err("%s: failed to save partition ID 0x%x - ret:%d\n",
+			       __func__, tpbuf->id, ret);
+			ffa_device_unregister(ffa_dev);
+			kfree(info);
+		}
 	}
 
 	kfree(pbuf);
@@ -1246,7 +1253,13 @@ static void ffa_setup_partitions(void)
 	if (!info)
 		return;
 	rwlock_init(&info->rw_lock);
-	xa_store(&drv_info->partition_info, drv_info->vm_id, info, GFP_KERNEL);
+	ret = xa_insert(&drv_info->partition_info, drv_info->vm_id,
+			info, GFP_KERNEL);
+	if (ret) {
+		pr_err("%s: failed to save Host partition ID 0x%x - ret:%d. Abort.\n",
+		       __func__, drv_info->vm_id, ret);
+		kfree(info);
+	}
 }
 
 static void ffa_partitions_cleanup(void)