From b2c681fc4a1d852f5b436660e7d3a967cf5e7333 Mon Sep 17 00:00:00 2001 From: Eugene Myers Date: Mon, 7 Feb 2022 16:45:22 -0500 Subject: [PATCH] security/intel/stm: Make STM setup MP safe Some processor families allow for SMM setup to be done in parallel. On processors that have this feature, the BIOS resource list becomes unusable for some processors during STM startup. This patch covers two cases: (1) The BIOS resource list becomes twice as long because the smm_relocation function is called twice - this is resolved by recreating the list on each invocation. (2) Not all processors receive the correct resource list pointer - this is resolved by having every processor execute the pointer calculation code, which is a lot faster then forcing all processors to spin lock waiting for this value to be calculated. This patch has been tested on a Purism L1UM-1X8C and Purism 15v4. Signed-off-by: Eugene Myers Change-Id: I7619038edc78f306bd7eb95844bd1598766f8b37 Reviewed-on: https://review.coreboot.org/c/coreboot/+/61689 Tested-by: build bot (Jenkins) Reviewed-by: Eugene Myers Reviewed-by: Philipp Deppenwiese --- src/security/intel/stm/StmPlatformResource.c | 5 +++++ src/security/intel/stm/StmPlatformSmm.c | 9 ++++++--- 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/src/security/intel/stm/StmPlatformResource.c b/src/security/intel/stm/StmPlatformResource.c index 75d52a26cf..4e56e2e574 100644 --- a/src/security/intel/stm/StmPlatformResource.c +++ b/src/security/intel/stm/StmPlatformResource.c @@ -167,9 +167,14 @@ static void add_msr_resources(void) /* * Add resources to BIOS resource database. */ + +extern uint8_t *m_stm_resources_ptr; + void add_resources_cmd(void) { + m_stm_resources_ptr = NULL; + add_simple_resources(); add_msr_resources(); diff --git a/src/security/intel/stm/StmPlatformSmm.c b/src/security/intel/stm/StmPlatformSmm.c index ef02ae3971..bcf935cb11 100644 --- a/src/security/intel/stm/StmPlatformSmm.c +++ b/src/security/intel/stm/StmPlatformSmm.c @@ -155,12 +155,15 @@ void stm_setup(uintptr_t mseg, int cpu, uintptr_t smbase, return; } + // This code moved here because paralled SMM set can cause + // some processor to receive a bad value + // calculate the location in SMRAM + addr_calc = mseg - CONFIG_BIOS_RESOURCE_LIST_SIZE; + stm_resource_heap = (uint8_t *) addr_calc; + if (cpu == 0) { // need to create the BIOS resource list once - // first calculate the location in SMRAM - addr_calc = mseg - CONFIG_BIOS_RESOURCE_LIST_SIZE; - stm_resource_heap = (uint8_t *) addr_calc; printk(BIOS_DEBUG, "STM: stm_resource_heap located at %p\n", stm_resource_heap); //setup the list