add gpio

hc

2023-12-04 f33f61bdb7ca6d5ebe7a78f9d8694b91360279ac

 kernel/arch/x86/platform/efi/efi_64.c
..
..
@@ -619,18 +619,16 @@
619
619
 
620
620
 /*
621
621
  * Makes the calling thread switch to/from efi_mm context. Can be used
622
- * for SetVirtualAddressMap() i.e. current->active_mm == init_mm as well
623
- * as during efi runtime calls i.e current->active_mm == current_mm.
624
- * We are not mm_dropping()/mm_grabbing() any mm, because we are not
625
- * losing/creating any references.
622
+ * in a kernel thread and user context. Preemption needs to remain disabled
623
+ * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
624
+ * can not change under us.
625
+ * It should be ensured that there are no concurent calls to this function.
626
626
  */
627
627
 void efi_switch_mm(struct mm_struct *mm)
628
628
 {
629
-	task_lock(current);
630
629
 	efi_scratch.prev_mm = current->active_mm;
631
630
 	current->active_mm = mm;
632
631
 	switch_mm(efi_scratch.prev_mm, mm, NULL);
633
-	task_unlock(current);
634
632
 }
635
633
 
636
634
 #ifdef CONFIG_EFI_MIXED