drivers/intel/fsp2_0: Make FSP Notify Phase APIs optional

The FSP API is used to notify the FSP about different phases in the
boot process. The current FSP specification supports three notify
phases:
 - Post PCI enumeration
 - Ready to Boot
 - End of Firmware

This patch attempts to make calling into the FSP Notify Phase APIs
optional by using native coreboot implementations to perform the
required lock down and chipset register configuration prior boot to
payload.

BUG=b:211954778
TEST=Able to build brya without any compilation issue and coreboot
log with this code changes when SKIP_FSP_NOTIFY_PHASE_READY_TO_BOOT
and SKIP_FSP_NOTIFY_PHASE_END_OF_FIRMWARE config enabled.

coreboot skipped calling FSP notify phase: 00000040.
coreboot skipped calling FSP notify phase: 000000f0.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: Ia95e9ec25ae797f2ac8e1c74145cf21e59867d64
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60402
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: EricR Lai <ericr_lai@compal.corp-partner.google.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>

src/drivers/intel/fsp2_0/Kconfig

@@ -310,4 +310,41 @@ config FSPS_USE_MULTI_PHASE_INIT
 	  SoC users to select this Kconfig to set EnableMultiPhaseSiliconInit to enable and
 	  execute FspMultiPhaseSiInit() API.
 
+config SKIP_FSP_NOTIFY_PHASE_AFTER_PCI_ENUM
+	bool
+	help
+	  The FSP API is used to notify the FSP about different phases in the boot process.
+	  The current FSP specification supports three notify phases:
+	  - Post PCI enumeration
+	  - Ready to Boot
+	  - End of Firmware
+	  Select this on a platform where you want to skip calling FSP Notify
+	  `Post PCI enumeration` API. Instead use coreboot native implementations
+	  to perform the required lock down and chipset register configuration prior
+	  boot to payload.
+
+config SKIP_FSP_NOTIFY_PHASE_READY_TO_BOOT
+	bool
+	help
+	  The FSP API is used to notify the FSP about different phases in the boot process.
+	  The current FSP specification supports three notify phases:
+	  - Post PCI enumeration
+	  - Ready to Boot
+	  - End of Firmware
+	  Select this on a platform where you want to skip calling FSP Notify `Ready to Boot`
+	  API. Instead use coreboot native implementations to perform the required lock down
+	  and chipset register configuration prior boot to payload.
+
+config SKIP_FSP_NOTIFY_PHASE_END_OF_FIRMWARE
+	bool
+	help
+	  The FSP API is used to notify the FSP about different phases in the boot process.
+	  The current FSP specification supports three notify phases:
+	  - Post PCI enumeration
+	  - Ready to Boot
+	  - End of Firmware
+	  Select this on a platform where you want to skip calling FSP Notify `End of Firmware`
+	  API. Instead use coreboot native implementations to perform the required lock down
+	  and chipset register configuration prior boot to payload.
+
 endif

src/drivers/intel/fsp2_0/notify.c

@@ -10,6 +10,7 @@
 
 struct fsp_notify_phase_data {
 	enum fsp_notify_phase notify_phase;
+	bool skip;
 	uint8_t post_code_before;
 	uint8_t post_code_after;
 	enum timestamp_id timestamp_before;
@@ -19,6 +20,7 @@ struct fsp_notify_phase_data {
 static const struct fsp_notify_phase_data notify_data[] = {
 	{
 		.notify_phase     = AFTER_PCI_ENUM,
+		.skip             = CONFIG(SKIP_FSP_NOTIFY_PHASE_AFTER_PCI_ENUM),
 		.post_code_before = POST_FSP_NOTIFY_BEFORE_ENUMERATE,
 		.post_code_after  = POST_FSP_NOTIFY_AFTER_ENUMERATE,
 		.timestamp_before = TS_FSP_BEFORE_ENUMERATE,
@@ -26,6 +28,7 @@ static const struct fsp_notify_phase_data notify_data[] = {
 	},
 	{
 		.notify_phase     = READY_TO_BOOT,
+		.skip             = CONFIG(SKIP_FSP_NOTIFY_PHASE_READY_TO_BOOT),
 		.post_code_before = POST_FSP_NOTIFY_BEFORE_FINALIZE,
 		.post_code_after  = POST_FSP_NOTIFY_AFTER_FINALIZE,
 		.timestamp_before = TS_FSP_BEFORE_FINALIZE,
@@ -33,6 +36,7 @@ static const struct fsp_notify_phase_data notify_data[] = {
 	},
 	{
 		.notify_phase     = END_OF_FIRMWARE,
+		.skip             = CONFIG(SKIP_FSP_NOTIFY_PHASE_END_OF_FIRMWARE),
 		.post_code_before = POST_FSP_NOTIFY_BEFORE_END_OF_FIRMWARE,
 		.post_code_after  = POST_FSP_NOTIFY_AFTER_END_OF_FIRMWARE,
 		.timestamp_before = TS_FSP_BEFORE_END_OF_FIRMWARE,
@@ -56,6 +60,11 @@ static void fsp_notify(enum fsp_notify_phase phase)
 	fsp_notify_fn fspnotify;
 	uint32_t ret;
 
+	if (data->skip) {
+		printk(BIOS_INFO, "coreboot skipped calling FSP notify phase: %08x.\n", phase);
+		return;
+	}
+
 	if (!fsps_hdr.notify_phase_entry_offset)
 		die("Notify_phase_entry_offset is zero!\n");