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-rw-r--r--src/soc/amd/common/block/psp/psp_smm.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/src/soc/amd/common/block/psp/psp_smm.c b/src/soc/amd/common/block/psp/psp_smm.c
index 114cf12add..eecdf02be7 100644
--- a/src/soc/amd/common/block/psp/psp_smm.c
+++ b/src/soc/amd/common/block/psp/psp_smm.c
@@ -47,6 +47,13 @@ static void clear_smm_flag(void)
smm_flag = 0;
}
+/*
+ * The MBOX_BIOS_CMD_SMM_INFO PSP mailbox command doesn't necessarily need be sent from SMM,
+ * but doing so allows the linker to sort out the addresses of c2p_buffer, p2c_buffer and
+ * smm_flag without us needing to pass this info between ramstage and smm. In the PSP gen2 case
+ * this will also make sure that the PSP MMIO base will be cached in SMM before the OS takes
+ * over so no SMN accesses will be needed during OS runtime.
+ */
int psp_notify_smm(void)
{
msr_t msr;