Patrick Georgi (pgeorgi@google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/11052
-gerrit
commit 3ec8109d372872b819840e555085bc50552418b2 Author: Rizwan Qureshi rizwan.qureshi@intel.com Date: Tue Jul 7 18:18:15 2015 +0530
Skylake: Fix microcode reload in bootblock cpu init
If Skylake microcode is being loaded from FIT, Skylake supports the PRMRR/SGX feature. If this is supported the FIT microcode load will set the msr (0x08b) with the patch ID one less than the ID in the microcode binary. This results in microcode getting reloaded again in the bootblock cpu init. Avoid the microcode reload by checking for PRMRR support.
BUG=chrome-os-partner:42046 BRANCH=None TEST=Built for glados and tested on RVP3
Change-Id: I06e59f5cad549098c7ba2dfa608cd94a0b3f0ae1 Signed-off-by: Patrick Georgi pgeorgi@chromium.org Original-Commit-Id: 6242b9dea283149bd0c968af1ba186647d37162d Original-Change-Id: Iea5a223aa625be3fc451e8ee5d3510f548b07f8b Original-Signed-off-by: Rizwan Qureshi rizwan.qureshi@intel.com Original-Reviewed-on: https://chromium-review.googlesource.com/286054 Original-Reviewed-by: Aaron Durbin adurbin@chromium.org --- src/soc/intel/skylake/bootblock/cpu.c | 24 +++++++++++++++++++++++- src/soc/intel/skylake/include/soc/msr.h | 2 +- 2 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/src/soc/intel/skylake/bootblock/cpu.c b/src/soc/intel/skylake/bootblock/cpu.c index d4506e5..2e3e000 100644 --- a/src/soc/intel/skylake/bootblock/cpu.c +++ b/src/soc/intel/skylake/bootblock/cpu.c @@ -178,11 +178,33 @@ static void check_for_clean_reset(void) soft_reset(); }
+static int need_microcode_update(void) +{ + /* If PRMRR/SGX is supported the FIT microcode load step will set + * msr 0x08b with the Patch revision id one less than the id in the + * microcode binary. The PRMRR support is indicated in the MSR + * MTRRCAP[12]. Check for this feature and avoid reloading the + * same microcode during early cpu initialization. + */ + msr = rdmsr(MTRRcap_MSR); + return (msr.lo & PRMRR_SUPPORTED) && (current_rev != patch->rev - 1); +} + static void bootblock_cpu_init(void) { + const struct microcode *patch; + u32 current_rev; + msr_t msr; + /* Set flex ratio and reset if needed */ set_flex_ratio_to_tdp_nominal(); check_for_clean_reset(); enable_rom_caching(); - intel_update_microcode_from_cbfs(); + + patch = intel_microcode_find(); + + current_rev = read_microcode_rev(); + + if (need_microcode_update()) + intel_update_microcode_from_cbfs(); } diff --git a/src/soc/intel/skylake/include/soc/msr.h b/src/soc/intel/skylake/include/soc/msr.h index b857dbe..3903757 100644 --- a/src/soc/intel/skylake/include/soc/msr.h +++ b/src/soc/intel/skylake/include/soc/msr.h @@ -105,6 +105,6 @@
/* MTRRcap_MSR bits */ #define SMRR_SUPPORTED (1<<11) -#define EMRR_SUPPORTED (1<<12) +#define PRMRR_SUPPORTED (1<<12)
#endif