svn commit: r258392 - head/sys/arm/arm

[Ian Lepore]

Author: ian
Date: Wed Nov 20 15:53:50 2013
New Revision: 258392
URL: http://svnweb.freebsd.org/changeset/base/258392

Log:
  Call cpu_setup() immediately after the page tables are installed.  This
  enables data cache and other chip-specific features.  It was previously
  done via an early SYSINIT, but it was being done after pmap and vm setup,
  and those setups need to use mutexes.  On some modern ARM platforms,
  the ldrex/strex instructions that implement mutexes require the data cache
  to be enabled.
  
  A nice side effect of enabling caching earlier is that it eliminates the
  multi-second pause that used to happen early in boot while physical memory
  and pmap and vm were being set up.  On boards with 1 GB or more of ram
  this pause was very noticible, sometimes 5-6 seconds.
  
  PR:		arm/183740

Modified:
  head/sys/arm/arm/machdep.c

Modified: head/sys/arm/arm/machdep.c
==============================================================================
--- head/sys/arm/arm/machdep.c	Wed Nov 20 13:22:22 2013	(r258391)
+++ head/sys/arm/arm/machdep.c	Wed Nov 20 15:53:50 2013	(r258392)
@@ -361,7 +361,6 @@ cpu_startup(void *dummy)
 #endif
 #endif
 
-	cpu_setup("");
 	identify_arm_cpu();
 
 	printf("real memory  = %ju (%ju MB)\n", (uintmax_t)ptoa(physmem),
@@ -1431,6 +1430,12 @@ initarm(struct arm_boot_params *abp)
 	cpu_domains(DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL * 2));
 
 	/*
+	 * Now that proper page tables are installed, call cpu_setup() to enable
+	 * instruction and data caches and other chip-specific features.
+	 */
+	cpu_setup("");
+
+	/*
 	 * Only after the SOC registers block is mapped we can perform device
 	 * tree fixups, as they may attempt to read parameters from hardware.
 	 */