arm64: Execute DSB during thread switching for TLB/cache maintenance
authorCatalin Marinas <catalin.marinas@arm.com>
Wed, 24 Apr 2013 13:47:02 +0000 (14:47 +0100)
committerCatalin Marinas <catalin.marinas@arm.com>
Thu, 25 Apr 2013 16:45:48 +0000 (17:45 +0100)
The DSB following TLB or cache maintenance ops must be run on the same
CPU. With kernel preemption enabled or for user-space cache maintenance
this may not be the case. This patch adds an explicit DSB in the
__switch_to() function.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/arm64/kernel/process.c

index c2cc249..116a60a 100644 (file)
@@ -313,6 +313,12 @@ struct task_struct *__switch_to(struct task_struct *prev,
        hw_breakpoint_thread_switch(next);
        contextidr_thread_switch(next);
 
+       /*
+        * Complete any pending TLB or cache maintenance on this CPU in case
+        * the thread migrates to a different CPU.
+        */
+       dsb();
+
        /* the actual thread switch */
        last = cpu_switch_to(prev, next);