soc/intel/lockdown: Allow locking down SPI and LPC in SMM

Heads payload uses APM_CNT_FINALIZE SMI to set and lock down the SPI
controller with PR0 flash protection for pre-Skylake platforms.

Add new option to skip LPC and FAST SPI lock down in coreboot and move
it to APM_CNT_FINALIZE SMI handler. Reuse the INTEL_CHIPSET_LOCKDOWN
option to prevent issuing APM_CNT_FINALIZE SMI on normal boot path,
like it was done on pre-Skylake platforms. As the locking on modern
SOCs became more complicated, separate the SPI and LPC locking into
new modules to make linking to SMM easier.

The expected configuration to leverage the feature is to unselect
INTEL_CHIPSET_LOCKDOWN and select SOC_INTEL_COMMON_SPI_LOCKDOWN_SMM.

Testing various microarchitectures happens on heads repository:
linuxboot/heads#1818

TEST=Lock the SPI flash using APM_CNT_FINALIZE in heads on Alder Lake
(Protectli VP66xx) and Comet Lake (Protectli VP46xx) platforms. Check
if flash is unlocked in the heads recovery console. Check if flash is
locked in the kexec'ed OS.

Upstream-Status: Submitted [CB:85278]
Change-Id: Icbcc6fcde90e5b0a999aacb720e2e3dc2748c838
Signed-off-by: Michał Żygowski <[email protected]>

Author: miczyg1

src/soc/intel/alderlake/finalize.c

@@ -85,7 +85,9 @@ static void soc_finalize(void *unused)
 	printk(BIOS_DEBUG, "Finalizing chipset.\n");
 
 	pch_finalize();
-	apm_control(APM_CNT_FINALIZE);
+	if (CONFIG(INTEL_CHIPSET_LOCKDOWN) || acpi_is_wakeup_s3())
+		apm_control(APM_CNT_FINALIZE);
+
 	tbt_finalize();
 	if (CONFIG(USE_FSP_NOTIFY_PHASE_READY_TO_BOOT) &&
 			 CONFIG(USE_FSP_NOTIFY_PHASE_END_OF_FIRMWARE))

src/soc/intel/cannonlake/finalize.c

@@ -87,7 +87,9 @@ static void soc_finalize(void *unused)
 	printk(BIOS_DEBUG, "Finalizing chipset.\n");
 
 	pch_finalize();
-	apm_control(APM_CNT_FINALIZE);
+	if (CONFIG(INTEL_CHIPSET_LOCKDOWN) || acpi_is_wakeup_s3())
+		apm_control(APM_CNT_FINALIZE);
+
 	if (CONFIG(DISABLE_HECI1_AT_PRE_BOOT) &&
 			CONFIG(SOC_INTEL_COMMON_BLOCK_HECI1_DISABLE_USING_PMC_IPC))
 		heci1_disable();

src/soc/intel/common/block/lpc/Makefile.mk

@@ -5,3 +5,7 @@ romstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_LPC) += lpc_lib.c
 
 ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_LPC) += lpc_lib.c
 ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_LPC) += lpc.c
+
+ifeq ($(CONFIG_SOC_INTEL_COMMON_SPI_LOCKDOWN_SMM),y)
+smm-$(CONFIG_SOC_INTEL_COMMON_BLOCK_LPC) += lpc_lib.c
+endif

src/soc/intel/common/block/smm/smihandler.c

@@ -15,12 +15,14 @@
 #include <device/pci_def.h>
 #include <device/pci_ops.h>
 #include <elog.h>
+#include <intelblocks/cfg.h>
 #include <intelblocks/fast_spi.h>
 #include <intelblocks/oc_wdt.h>
 #include <intelblocks/pmclib.h>
 #include <intelblocks/smihandler.h>
 #include <intelblocks/tco.h>
 #include <intelblocks/uart.h>
+#include <intelpch/lockdown.h>
 #include <smmstore.h>
 #include <soc/nvs.h>
 #include <soc/pci_devs.h>
@@ -347,6 +349,14 @@ static void finalize(void)
 	}
 	finalize_done = 1;
 
+	if (CONFIG(SOC_INTEL_COMMON_SPI_LOCKDOWN_SMM)) {
+		/* SPI lock down configuration */
+		fast_spi_lockdown_bios(CHIPSET_LOCKDOWN_COREBOOT);
+
+		/* LPC/eSPI lock down configuration */
+		lpc_lockdown_config(CHIPSET_LOCKDOWN_COREBOOT);
+	}
+
 	if (CONFIG(SPI_FLASH_SMM))
 		/* Re-init SPI driver to handle locked BAR */
 		fast_spi_init();

src/soc/intel/common/pch/include/intelpch/lockdown.h

@@ -22,4 +22,7 @@ int get_lockdown_config(void);
  */
 void soc_lockdown_config(int chipset_lockdown);
 
+void fast_spi_lockdown_bios(int chipset_lockdown);
+void lpc_lockdown_config(int chipset_lockdown);
+
 #endif /* SOC_INTEL_COMMON_PCH_LOCKDOWN_H */

src/soc/intel/common/pch/lockdown/Kconfig

@@ -3,7 +3,22 @@
 config SOC_INTEL_COMMON_PCH_LOCKDOWN
 	bool
 	default n
+	select HAVE_INTEL_CHIPSET_LOCKDOWN
 	help
 	  This option allows to have chipset lockdown for DMI, FAST_SPI and
 	  soc_lockdown_config() to implement any additional lockdown as PMC,
 	  LPC for supported PCH.
+
+config SOC_INTEL_COMMON_SPI_LOCKDOWN_SMM
+	bool "Lock down SPI controller in SMM"
+	default n
+	depends on HAVE_SMI_HANDLER && !INTEL_CHIPSET_LOCKDOWN
+	select SPI_FLASH_SMM
+	help
+	  This option allows to have chipset lockdown for FAST_SPI and LPC for
+	  supported PCH. If selected, coreboot will skip locking down the SPI
+	  and LPC controller. The payload or OS is responsible for locking it
+	  using APM_CNT_FINALIZE SMI. Used by heads to set and lock PR0 flash
+	  protection.
+
+	  If unsure, say N.

src/soc/intel/common/pch/lockdown/Makefile.mk

@@ -1,2 +1,7 @@
 ## SPDX-License-Identifier: GPL-2.0-only
 ramstage-$(CONFIG_SOC_INTEL_COMMON_PCH_LOCKDOWN) += lockdown.c
+ramstage-$(CONFIG_SOC_INTEL_COMMON_PCH_LOCKDOWN) += lockdown_lpc.c
+ramstage-$(CONFIG_SOC_INTEL_COMMON_PCH_LOCKDOWN) += lockdown_spi.c
+
+smm-$(CONFIG_SOC_INTEL_COMMON_SPI_LOCKDOWN_SMM) += lockdown_lpc.c
+smm-$(CONFIG_SOC_INTEL_COMMON_SPI_LOCKDOWN_SMM) += lockdown_spi.c

src/soc/intel/common/pch/lockdown/lockdown.c

@@ -1,7 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <bootstate.h>
-#include <dasharo/options.h>
 #include <intelblocks/cfg.h>
 #include <intelblocks/fast_spi.h>
 #include <intelblocks/lpc_lib.h>
@@ -61,56 +60,17 @@ static void fast_spi_lockdown_cfg(int chipset_lockdown)
 	/* Set FAST_SPI opcode menu */
 	fast_spi_set_opcode_menu();
 
-	/* Discrete Lock Flash PR registers */
-	fast_spi_pr_dlock();
-
 	/* Check if SPI transaction is pending */
 	fast_spi_cycle_in_progress();
 
 	/* Clear any outstanding status bits like AEL, FCERR, FDONE, SAF etc. */
 	fast_spi_clear_outstanding_status();
 
-	/* Lock FAST_SPIBAR */
-	fast_spi_lock_bar();
-
 	/* Set Vendor Component Lock (VCL) */
 	fast_spi_vscc0_lock();
 
-	/* Set BIOS Interface Lock, BIOS Lock */
-	if (chipset_lockdown == CHIPSET_LOCKDOWN_COREBOOT) {
-		/* BIOS Interface Lock */
-		fast_spi_set_bios_interface_lock_down();
-
-		/* Only allow writes in SMM */
-		if (CONFIG(BOOTMEDIA_SMM_BWP) && is_smm_bwp_permitted()) {
-			fast_spi_set_eiss();
-			fast_spi_enable_wp();
-		}
-
-		/* BIOS Lock */
-		fast_spi_set_lock_enable();
-
-		/* EXT BIOS Lock */
-		fast_spi_set_ext_bios_lock_enable();
-	}
-}
-
-static void lpc_lockdown_config(int chipset_lockdown)
-{
-	/* Set BIOS Interface Lock, BIOS Lock */
-	if (chipset_lockdown == CHIPSET_LOCKDOWN_COREBOOT) {
-		/* BIOS Interface Lock */
-		lpc_set_bios_interface_lock_down();
-
-		/* Only allow writes in SMM */
-		if (CONFIG(BOOTMEDIA_SMM_BWP) && is_smm_bwp_permitted()) {
-			lpc_set_eiss();
-			lpc_enable_wp();
-		}
-
-		/* BIOS Lock */
-		lpc_set_lock_enable();
-	}
+	if (!CONFIG(SOC_INTEL_COMMON_SPI_LOCKDOWN_SMM))
+		fast_spi_lockdown_bios(chipset_lockdown);
 }
 
 static void sa_lockdown_config(int chipset_lockdown)
@@ -136,8 +96,9 @@ static void platform_lockdown_config(void *unused)
 	/* SPI lock down configuration */
 	fast_spi_lockdown_cfg(chipset_lockdown);
 
-	/* LPC/eSPI lock down configuration */
-	lpc_lockdown_config(chipset_lockdown);
+	if (!CONFIG(SOC_INTEL_COMMON_SPI_LOCKDOWN_SMM))
+		/* LPC/eSPI lock down configuration */
+		lpc_lockdown_config(chipset_lockdown);
 
 	/* GPMR lock down configuration */
 	gpmr_lockdown_cfg();

src/soc/intel/common/pch/lockdown/lockdown_lpc.c

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <dasharo/options.h>
+#include <intelblocks/cfg.h>
+#include <intelblocks/lpc_lib.h>
+#include <intelpch/lockdown.h>
+
+void lpc_lockdown_config(int chipset_lockdown)
+{
+	/* Set BIOS Interface Lock, BIOS Lock */
+	if (chipset_lockdown == CHIPSET_LOCKDOWN_COREBOOT) {
+		/* BIOS Interface Lock */
+		lpc_set_bios_interface_lock_down();
+
+		/* Only allow writes in SMM */
+		if (CONFIG(BOOTMEDIA_SMM_BWP) && is_smm_bwp_permitted()) {
+			lpc_set_eiss();
+			lpc_enable_wp();
+		}
+
+		/* BIOS Lock */
+		lpc_set_lock_enable();
+	}
+}

src/soc/intel/common/pch/lockdown/lockdown_spi.c

@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <dasharo/options.h>
+#include <intelblocks/cfg.h>
+#include <intelblocks/fast_spi.h>
+#include <intelpch/lockdown.h>
+
+void fast_spi_lockdown_bios(int chipset_lockdown)
+{
+	/* Discrete Lock Flash PR registers */
+	fast_spi_pr_dlock();
+
+	/* Lock FAST_SPIBAR */
+	fast_spi_lock_bar();
+
+	/* Set BIOS Interface Lock, BIOS Lock */
+	if (chipset_lockdown == CHIPSET_LOCKDOWN_COREBOOT) {
+		/* BIOS Interface Lock */
+		fast_spi_set_bios_interface_lock_down();
+
+		/* Only allow writes in SMM */
+		if (CONFIG(BOOTMEDIA_SMM_BWP) && is_smm_bwp_permitted()) {
+			fast_spi_set_eiss();
+			fast_spi_enable_wp();
+		}
+
+		/* BIOS Lock */
+		fast_spi_set_lock_enable();
+
+		/* EXT BIOS Lock */
+		fast_spi_set_ext_bios_lock_enable();
+	}
+}