Timothy Pearson (tpearson@raptorengineeringinc.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/13172
-gerrit
commit 72802f47cfe5a05e5e6d2cba2af7635e05427b79 Author: Timothy Pearson tpearson@raptorengineeringinc.com Date: Tue Nov 24 14:12:07 2015 -0600
cpu/amd/fam10h-fam15h: Honor CMOS option to disable CPB (core boost)
On certain systems and CPUs Core Performance Boost (CPB) may cause sporadic system lockups. This issue is also somewhat known on the various proprietary BIOSes, therefore it seems to be a hardware incompatibility when present.
Allow the user to disable CBP if needed.
Change-Id: Id6395d067d48963f6c084ad0bf79e23419af24d8 Signed-off-by: Timothy Pearson tpearson@raptorengineeringinc.com --- src/cpu/amd/family_10h-family_15h/init_cpus.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/src/cpu/amd/family_10h-family_15h/init_cpus.c b/src/cpu/amd/family_10h-family_15h/init_cpus.c index e2a1bf3..c1ff240 100644 --- a/src/cpu/amd/family_10h-family_15h/init_cpus.c +++ b/src/cpu/amd/family_10h-family_15h/init_cpus.c @@ -987,6 +987,7 @@ void cpuSetAMDMSR(uint8_t node_id) u32 platform; uint64_t revision; uint8_t enable_c_states; + uint8_t enable_cpb;
printk(BIOS_DEBUG, "cpuSetAMDMSR ");
@@ -1078,6 +1079,19 @@ void cpuSetAMDMSR(uint8_t node_id) enable_c_states = 0; #endif
+ if (revision & AMD_FAM15_ALL) { + enable_cpb = 1; + if (get_option(&nvram, "cpu_core_boost") == CB_SUCCESS) + enable_cpb = !!nvram; + + if (!enable_cpb) { + /* Disable Core Performance Boost */ + msr = rdmsr(0xc0010015); + msr.lo |= (0x1 << 25); /* CpbDis = 1 */ + wrmsr(0xc0010015, msr); + } + } + printk(BIOS_DEBUG, " done\n"); }