[coreboot-gerrit] Change in coreboot[master]: src/cpu/x86/smm: move console init to thread safe section

[Rocky Phagura (Code Review)]

Attention is currently required from: Rocky Phagura.
Hello Rocky Phagura,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/coreboot/+/52518

to review the following change.

Change subject: src/cpu/x86/smm: move console init to thread safe section
......................................................................

src/cpu/x86/smm: move console init to thread safe section

This patch moves the console init code in SMM to a thread safe location
which is right after obtaining the lock.

Tested on DeltaLake mainboard with SMM enabled.

Change-Id: I7e8af35d1cde78b327144b6a9da528ae7870e874
Signed-off-by: Rocky Phagura 
---
M src/cpu/x86/smm/smm_module_handler.c
1 file changed, 10 insertions(+), 8 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/18/52518/1

diff --git a/src/cpu/x86/smm/smm_module_handler.c b/src/cpu/x86/smm/smm_module_handler.c
index f7cf928..3b10d13 100644
--- a/src/cpu/x86/smm/smm_module_handler.c
+++ b/src/cpu/x86/smm/smm_module_handler.c
@@ -131,14 +131,10 @@
     * will be the same across CPUs as well as multiple SMIs. */
    gnvs = (void *)(uintptr_t)smm_runtime.gnvs_ptr;

-	if (cpu >= CONFIG_MAX_CPUS) {
-		console_init();
-		printk(BIOS_CRIT,
-		       "Invalid CPU number assigned in SMM stub: %d\n", cpu);
-		return;
-	}
-
-	/* Are we ok to execute the handler? */
+	/*
+	 * Only thread safe code should be executed before obtaining
+	 * a lock
+	 */
    if (!smi_obtain_lock()) {
    	/* For security reasons we don't release the other CPUs
    	 * until the CPU with the lock is actually done */
@@ -150,6 +146,12 @@
    	return;
    }

+	if (cpu > CONFIG_MAX_CPUS) {
+		console_init();
+		printk(BIOS_CRIT,
+		       "Invalid CPU number assigned in SMM stub: %d\n", cpu);
+		return;
+	}
    smi_backup_pci_address();

console_init();