svn commit: r323471 - stable/11/sys/arm/broadcom/bcm2835

[Ian Lepore]

Author: ian
Date: Mon Sep 11 22:35:20 2017
New Revision: 323471
URL: https://svnweb.freebsd.org/changeset/base/323471

Log:
  MFC r323132-r323133
  
  r323132:
  The latest RPi firmware leaves secondary cores in a wait-for-event (WFE)
  state to save power, so after writing the entry point address for a core to
  the mailbox, use a dsb() to synchronize the execution pipeline to the data
  written, then use an sev() to wake up the core.
  
  Submitted by:	Sylvain Garrigues <sylgar at gmail.com>
  
  r323133:
  Change leading spaces to tabs, no functional change.

Modified:
  stable/11/sys/arm/broadcom/bcm2835/bcm2836_mp.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/arm/broadcom/bcm2835/bcm2836_mp.c
==============================================================================
--- stable/11/sys/arm/broadcom/bcm2835/bcm2836_mp.c	Mon Sep 11 22:33:29 2017	(r323470)
+++ stable/11/sys/arm/broadcom/bcm2835/bcm2836_mp.c	Mon Sep 11 22:35:20 2017	(r323471)
@@ -114,7 +114,9 @@ platform_mp_start_ap(void)
 		/* set entry point to mailbox 3 */
 		BSWR4(MBOX3SET_CORE(i),
 		    (uint32_t)pmap_kextract((vm_offset_t)mpentry));
-		wmb();
+		/* Firmware put cores in WFE state, need SEV to wake up. */
+		dsb();
+		sev();
 
 		/* wait for bootup */
 		retry = 1000;