From 13cc952a13ea29d9c5016a861d97da8326c87c4e Mon Sep 17 00:00:00 2001 From: Aaron Durbin Date: Mon, 1 Apr 2013 16:49:31 -0500 Subject: haswell: keep ROM cache enabled The MP code on haswell was mirroring the BSPs MTRRs. In addition it was cleaning up the ROM cache so that the MTRR register values were the same once the OS was booted. Since the hyperthread sibling of the BSP was going through this path the ROM cache was getting torn down once the hyperthread was brought up. That said, there was no differnce in observed boot time keeping the ROM cache enabled. Change-Id: I2a59988fcfeea9291202c961636ea761c2538837 Signed-off-by: Aaron Durbin Reviewed-on: http://review.coreboot.org/3008 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer --- src/cpu/intel/haswell/mp_init.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'src/cpu') diff --git a/src/cpu/intel/haswell/mp_init.c b/src/cpu/intel/haswell/mp_init.c index cc1389247e..ddcff6c834 100644 --- a/src/cpu/intel/haswell/mp_init.c +++ b/src/cpu/intel/haswell/mp_init.c @@ -181,8 +181,12 @@ ap_init(unsigned int cpu, void *microcode_ptr) /* After SMM relocation a 2nd microcode load is required. */ intel_microcode_load_unlocked(microcode_ptr); - /* Cleanup ROM caching. */ - cleanup_rom_caching(); + /* The MTRR resources are core scoped. Therefore, there is no need + * to do the same work twice. Additionally, this check keeps the + * ROM cache enabled on the BSP since its hyperthread sibling won't + * call cleanup_rom_caching(). */ + if ((lapicid() & 1) == 0) + cleanup_rom_caching(); /* FIXME(adurbin): park CPUs properly -- preferably somewhere in a * reserved part of memory that the OS cannot get to. */ -- cgit v1.2.3