soc/intel/{apl,cnl,dnv,skl}: Skip ucode loading by FSP-T

It is a requirement for Firmware to have Firmware Interface Table (FIT),
which contains pointers to each microcode update.
The microcode update is loaded for all logical processors before reset vector.

FSPT_UPD.MicrocodeRegionBase and FSPT_UPD.MicrocodeRegionLength are
input parameters to TempRamInit API.
If these values are 0, FSP will not attempt to update microcode.

Since Gen-4 all IA-SoC has FIT loading ucode even before cpu reset in place
hence skipping FSP-T loading ucode after CPU reset options.

Also removed unused kconfig CONFIG_CPU_MICROCODE_CBFS_LOC and
CONFIG_CPU_MICROCODE_CBFS_LEN

Change-Id: I3a406fa0e2e62e3363c2960e173dc5f5f5ca0455
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37187
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: David Guckian
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/cpu/Makefile.inc

@@ -59,9 +59,4 @@ $(obj)/cpu_microcode_blob.bin: $$(wildcard $$(cpu_microcode_bins))
 
 cpu_microcode_blob.bin-file ?= $(obj)/cpu_microcode_blob.bin
 cpu_microcode_blob.bin-type := microcode
-
-ifneq ($(CONFIG_CPU_MICROCODE_CBFS_LOC),)
-cpu_microcode_blob.bin-COREBOOT-position := $(CONFIG_CPU_MICROCODE_CBFS_LOC)
-else
 cpu_microcode_blob.bin-align := 16
-endif

src/drivers/intel/fsp2_0/Kconfig

@@ -37,21 +37,6 @@ config ADD_FSP_BINARIES
 	  Add the FSP-M and FSP-S binaries to CBFS. Currently coreboot does not
 	  use the FSP-T binary and it is not added.
 
-config CPU_MICROCODE_CBFS_LEN
-	hex "Microcode update region length in bytes"
-	depends on FSP_CAR
-	default 0x0
-	help
-	  The length in bytes of the microcode update region.
-
-config CPU_MICROCODE_CBFS_LOC
-	hex "Microcode update base address in CBFS"
-	depends on FSP_CAR
-	default 0x0
-	help
-	  The location (base address) in CBFS that contains the
-	  microcode update binary.
-
 config FSP_T_CBFS
 	string "Name of FSP-T in CBFS"
 	depends on FSP_CAR

src/soc/intel/apollolake/fspcar.c

@@ -25,6 +25,17 @@ const FSPT_UPD temp_ram_init_params = {
 	.FsptCommonUpd = {
 		.Revision = 0,
 		.Reserved = {0},
+		/*
+		 * It is a requirement for firmware to have Firmware Interface Table
+		 * (FIT), which contains pointers to each microcode update.
+		 * The microcode update is loaded for all logical processors before
+		 * cpu reset vector.
+		 *
+		 * All SoC since Gen-4 has above mechanism in place to load microcode
+		 * even before hitting CPU reset vector. Hence skipping FSP-T loading
+		 * microcode after CPU reset by passing '0' value to
+		 * FSPT_UPD.MicrocodeRegionBase and FSPT_UPD.MicrocodeRegionLength.
+		 */
 		.MicrocodeRegionBase = 0,
 		.MicrocodeRegionLength = 0,
 		.CodeRegionBase =

src/soc/intel/cannonlake/bootblock/bootblock.c

@@ -30,10 +30,19 @@ const FSPT_UPD temp_ram_init_params = {
 		.Reserved = {0},
 	},
 	.FsptCoreUpd = {
-		.MicrocodeRegionBase =
-			(uint32_t)CONFIG_CPU_MICROCODE_CBFS_LOC,
-		.MicrocodeRegionSize =
-			(uint32_t)CONFIG_CPU_MICROCODE_CBFS_LEN,
+		/*
+		 * It is a requirement for firmware to have Firmware Interface Table
+		 * (FIT), which contains pointers to each microcode update.
+		 * The microcode update is loaded for all logical processors before
+		 * cpu reset vector.
+		 *
+		 * All SoC since Gen-4 has above mechanism in place to load microcode
+		 * even before hitting CPU reset vector. Hence skipping FSP-T loading
+		 * microcode after CPU reset by passing '0' value to
+		 * FSPT_UPD.MicrocodeRegionBase and FSPT_UPD.MicrocodeRegionLength.
+		 */
+		.MicrocodeRegionBase = 0,
+		.MicrocodeRegionLength = 0,
 		.CodeRegionBase =
 			(uint32_t)(0x100000000ULL - CONFIG_ROM_SIZE),
 		.CodeRegionSize = (uint32_t)CONFIG_ROM_SIZE,

src/soc/intel/denverton_ns/Kconfig

@@ -108,14 +108,6 @@ config DCACHE_BSP_STACK_SIZE
 	hex
 	default 0x10000
 
-config CPU_MICROCODE_CBFS_LOC
-	hex
-	default 0xfff20040
-
-config CPU_MICROCODE_CBFS_LEN
-	hex
-	default 0x0ff80
-
 config CPU_BCLK_MHZ
 	int
 	default 100

src/soc/intel/denverton_ns/bootblock/bootblock.c

@@ -31,10 +31,19 @@ const FSPT_UPD temp_ram_init_params = {
 			.Reserved = {0},
 	},
 	.FsptCoreUpd = {
-			.MicrocodeRegionBase =
-				(UINT32)CONFIG_CPU_MICROCODE_CBFS_LOC,
-			.MicrocodeRegionLength =
-				(UINT32)CONFIG_CPU_MICROCODE_CBFS_LEN,
+			/*
+			 * It is a requirement for firmware to have Firmware Interface Table
+			 * (FIT), which contains pointers to each microcode update.
+			 * The microcode update is loaded for all logical processors before
+			 * cpu reset vector.
+			 *
+			 * All SoC since Gen-4 has above mechanism in place to load microcode
+			 * even before hitting CPU reset vector. Hence skipping FSP-T loading
+			 * microcode after CPU reset by passing '0' value to
+			 * FSPT_UPD.MicrocodeRegionBase and FSPT_UPD.MicrocodeRegionLength.
+			 */
+			.MicrocodeRegionBase = 0,
+			.MicrocodeRegionLength = 0,
 			.CodeRegionBase =
 				(UINT32)(0x100000000ULL - CONFIG_ROM_SIZE),
 			.CodeRegionLength = (UINT32)CONFIG_ROM_SIZE,

src/soc/intel/skylake/fspcar.c

@@ -23,10 +23,19 @@ const FSPT_UPD temp_ram_init_params = {
 		.Reserved = {0},
 	},
 	.FsptCoreUpd = {
-		.MicrocodeRegionBase =
-			(uint32_t)CONFIG_CPU_MICROCODE_CBFS_LOC,
-		.MicrocodeRegionSize =
-			(uint32_t)CONFIG_CPU_MICROCODE_CBFS_LEN,
+		/*
+		 * It is a requirement for firmware to have Firmware Interface Table
+		 * (FIT), which contains pointers to each microcode update.
+		 * The microcode update is loaded for all logical processors before
+		 * cpu reset vector.
+		 *
+		 * All SoC since Gen-4 has above mechanism in place to load microcode
+		 * even before hitting CPU reset vector. Hence skipping FSP-T loading
+		 * microcode after CPU reset by passing '0' value to
+		 * FSPT_UPD.MicrocodeRegionBase and FSPT_UPD.MicrocodeRegionLength.
+		 */
+		.MicrocodeRegionBase = 0,
+		.MicrocodeRegionLength = 0,
 		.CodeRegionBase =
 			(uint32_t)(0x100000000ULL - CONFIG_ROM_SIZE),
 		.CodeRegionSize = (uint32_t)CONFIG_ROM_SIZE,