mm/sharepool: Add an interface to obtain an id

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5DS9S
CVE: NA

-------------------------------------------------

The DVPP address space is per process or per sharing group.
During sp_free and unshare, you need to know which address
space the current address belongs to.
Signed-off-by: NZhou Guanghui <zhouguanghui1@huawei.com>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

include/linux/share_pool.h

@@ -284,6 +284,9 @@ extern bool mg_is_sharepool_addr(unsigned long addr);
 extern int mg_sp_group_add_task(int pid, unsigned long prot, int spg_id);
 extern int sp_group_add_task(int pid, int spg_id);
 
+extern int sp_id_of_current(void);
+extern int mg_sp_id_of_current(void);
+
 extern void sp_area_drop(struct vm_area_struct *vma);
 extern int sp_group_exit(struct mm_struct *mm);
 extern void sp_group_post_exit(struct mm_struct *mm);
@@ -431,6 +434,15 @@ static inline int mg_sp_unshare(unsigned long va, unsigned long size)
 	return -EPERM;
 }
 
+static inline int sp_id_of_current(void)
+{
+	return -EPERM;
+}
+
+static inline int mg_sp_id_of_current(void)
+{
+	return -EPERM;
+}
 
 static inline void sp_init_mm(struct mm_struct *mm)
 {

mm/share_pool.c

@@ -1734,6 +1734,43 @@ int sp_group_del_task(int pid, int spg_id)
 }
 EXPORT_SYMBOL_GPL(sp_group_del_task);
 
+int sp_id_of_current(void)
+{
+	int ret, spg_id;
+	struct sp_group_master *master;
+
+	if (current->flags & PF_KTHREAD || !current->mm)
+		return -EINVAL;
+
+	down_read(&sp_group_sem);
+	master = current->mm->sp_group_master;
+	if (master && master->local) {
+		spg_id = master->local->id;
+		up_read(&sp_group_sem);
+		return spg_id;
+	}
+	up_read(&sp_group_sem);
+
+	down_write(&sp_group_sem);
+	ret = sp_mapping_group_setup_local(current->mm);
+	if (ret) {
+		up_write(&sp_group_sem);
+		return ret;
+	}
+	master = current->mm->sp_group_master;
+	spg_id = master->local->id;
+	up_write(&sp_group_sem);
+
+	return spg_id;
+}
+EXPORT_SYMBOL_GPL(sp_id_of_current);
+
+int mg_sp_id_of_current(void)
+{
+	return sp_id_of_current();
+}
+EXPORT_SYMBOL_GPL(mg_sp_id_of_current);
+
 /* the caller must hold sp_area_lock */
 static void __insert_sp_area(struct sp_area *spa)
 {