security/intel/txt: Issue a global reset when TXT_RESET bit is set

Although TXT specification says to do power cycle reset if TXT_RESET
is set, all Intel provided implementations issue a global reset here.

TEST=Perform ungraceful shutdown after SENTER to trigger SCLEAN path
on Dell OptiPlex 9010 and successfully call ACM SCLEAN.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Change-Id: I8ee2400fab20857ff89b14bb7b662a938b775304
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59639
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/security/intel/txt/common.c

@@ -27,7 +27,7 @@
 #include "txt_getsec.h"
 
 /* Usual security practice: if an unexpected error happens, reboot */
-static void __noreturn txt_reset_platform(void)
+void __noreturn txt_reset_platform(void)
 {
 #if CONFIG(SOC_INTEL_COMMON_BLOCK_SA)
 	global_reset();

src/security/intel/txt/romstage.c

@@ -108,8 +108,8 @@ void intel_txt_romstage_init(void)
 		printk(BIOS_ERR, "TEE-TXT: Secrets remain in memory. SCLEAN is required.\n");
 
 		if (txt_ests & TXT_ESTS_TXT_RESET_STS) {
-			printk(BIOS_ERR, "TEE-TXT: TXT_RESET bit set, doing full reset!\n");
-			full_reset();
+			printk(BIOS_ERR, "TEE-TXT: TXT_RESET bit set, doing global reset!\n");
+			txt_reset_platform();
 		}
 
 		/* FIXME: Clear SLP_TYP# */

src/security/intel/txt/txt.h

@@ -18,7 +18,7 @@
 #define ACM_E_PLATFORM_IS_NOT_PROD          0x10
 
 void intel_txt_romstage_init(void);
-
+void __noreturn txt_reset_platform(void);
 void intel_txt_log_bios_acm_error(void);
 int intel_txt_log_acm_error(const uint32_t acm_error);
 void intel_txt_log_spad(void);