src: Never overwrite `fadt->flags`

Instead, just flip the desired bits using bitwise operations. As this is
initially zero, the resulting value is the same. This allows flags to be
set from anywhere regardless of execution order.

Tested on Asus P8Z77-V LX2 with Linux 5.7.6 and Windows 10 at the end of
the patch train, both operating systems are able to boot successfully.

Change-Id: Icfd580a20524936cd0adac574331b09fb2aea925
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43387
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

11 files changed, 20 insertions, 20 deletions

diff --git a/src/soc/amd/picasso/acpi.c b/src/soc/amd/picasso/acpi.c
index 90ea8250e4..d3966607e2 100644
--- a/src/soc/amd/picasso/acpi.c
+++ b/src/soc/amd/picasso/acpi.c
@@ -119,7 +119,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->century = 0;	/* 0x7f to make rtc alarm work */
 	fadt->iapc_boot_arch = ACPI_FADT_LEGACY_DEVICES | ACPI_FADT_8042;
 	fadt->res2 = 0;		/* reserved, MUST be 0 ACPI 3.0 */
-	fadt->flags = ACPI_FADT_WBINVD | /* See table 5-10 ACPI 3.0a spec */
+	fadt->flags |= ACPI_FADT_WBINVD | /* See table 5-10 ACPI 3.0a spec */
 				ACPI_FADT_C1_SUPPORTED |
 				ACPI_FADT_SLEEP_BUTTON |
 				ACPI_FADT_S4_RTC_WAKE |
diff --git a/src/soc/amd/stoneyridge/acpi.c b/src/soc/amd/stoneyridge/acpi.c
index 797dece0ef..fb8a469d34 100644
--- a/src/soc/amd/stoneyridge/acpi.c
+++ b/src/soc/amd/stoneyridge/acpi.c
@@ -91,7 +91,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->century = 0;	/* 0x7f to make rtc alarm work */
 	fadt->iapc_boot_arch = FADT_BOOT_ARCH;	/* See table 5-10 */
 	fadt->res2 = 0;		/* reserved, MUST be 0 ACPI 3.0 */
-	fadt->flags = ACPI_FADT_WBINVD | /* See table 5-10 ACPI 3.0a spec */
+	fadt->flags |= ACPI_FADT_WBINVD | /* See table 5-10 ACPI 3.0a spec */
 				ACPI_FADT_C1_SUPPORTED |
 				ACPI_FADT_SLEEP_BUTTON |
 				ACPI_FADT_S4_RTC_WAKE |
diff --git a/src/soc/intel/baytrail/fadt.c b/src/soc/intel/baytrail/fadt.c
index ba38588cfd..b19d4ce6ee 100644
--- a/src/soc/intel/baytrail/fadt.c
+++ b/src/soc/intel/baytrail/fadt.c
@@ -41,7 +41,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->century = 0x00;
 	fadt->iapc_boot_arch = ACPI_FADT_LEGACY_DEVICES | ACPI_FADT_8042;
 
-	fadt->flags = ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
+	fadt->flags |= ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
 			ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
 			ACPI_FADT_RESET_REGISTER | ACPI_FADT_SEALED_CASE |
 			ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;
diff --git a/src/soc/intel/braswell/fadt.c b/src/soc/intel/braswell/fadt.c
index ba38588cfd..b19d4ce6ee 100644
--- a/src/soc/intel/braswell/fadt.c
+++ b/src/soc/intel/braswell/fadt.c
@@ -41,7 +41,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->century = 0x00;
 	fadt->iapc_boot_arch = ACPI_FADT_LEGACY_DEVICES | ACPI_FADT_8042;
 
-	fadt->flags = ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
+	fadt->flags |= ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
 			ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
 			ACPI_FADT_RESET_REGISTER | ACPI_FADT_SEALED_CASE |
 			ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;
diff --git a/src/soc/intel/broadwell/fadt.c b/src/soc/intel/broadwell/fadt.c
index eb38593376..4e4074ff6d 100644
--- a/src/soc/intel/broadwell/fadt.c
+++ b/src/soc/intel/broadwell/fadt.c
@@ -40,7 +40,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->century = 0x00;
 	fadt->iapc_boot_arch = ACPI_FADT_LEGACY_DEVICES | ACPI_FADT_8042;
 
-	fadt->flags = ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
+	fadt->flags |= ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
 			ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
 			ACPI_FADT_RESET_REGISTER | ACPI_FADT_SEALED_CASE |
 			ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;
diff --git a/src/soc/intel/common/block/acpi/acpi.c b/src/soc/intel/common/block/acpi/acpi.c
index 279bf69dff..1ce34fa7f4 100644
--- a/src/soc/intel/common/block/acpi/acpi.c
+++ b/src/soc/intel/common/block/acpi/acpi.c
@@ -119,10 +119,10 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->duty_offset = 1;
 	fadt->day_alrm = 0xd;
 
-	fadt->flags = ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
-	    ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
-	    ACPI_FADT_RESET_REGISTER | ACPI_FADT_SEALED_CASE |
-	    ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;
+	fadt->flags |= ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
+			ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
+			ACPI_FADT_RESET_REGISTER | ACPI_FADT_SEALED_CASE |
+			ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;
 
 	fadt->reset_reg.space_id = 1;
 	fadt->reset_reg.bit_width = 8;
diff --git a/src/soc/intel/denverton_ns/acpi.c b/src/soc/intel/denverton_ns/acpi.c
index eea324952f..99782b7ff0 100644
--- a/src/soc/intel/denverton_ns/acpi.c
+++ b/src/soc/intel/denverton_ns/acpi.c
@@ -140,10 +140,10 @@ void soc_fill_fadt(acpi_fadt_t *fadt)
 	fadt->century = 0x00;
 	fadt->iapc_boot_arch = ACPI_FADT_LEGACY_DEVICES | ACPI_FADT_8042;
 
-	fadt->flags = ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
-		      ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
-		      ACPI_FADT_RESET_REGISTER | ACPI_FADT_SLEEP_TYPE |
-		      ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;
+	fadt->flags |= ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
+		       ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
+		       ACPI_FADT_RESET_REGISTER | ACPI_FADT_SLEEP_TYPE |
+		       ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;
 
 	/* Reset Register */
 	fadt->reset_reg.space_id = ACPI_ADDRESS_SPACE_IO;
diff --git a/src/soc/intel/quark/acpi.c b/src/soc/intel/quark/acpi.c
index 628ef3afe3..44e9f2868b 100644
--- a/src/soc/intel/quark/acpi.c
+++ b/src/soc/intel/quark/acpi.c
@@ -25,7 +25,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	uint32_t pmbase = pci_read_config32(dev, R_QNC_LPC_PM1BLK)
 		& B_QNC_LPC_PM1BLK_MASK;
 
-	fadt->flags = ACPI_FADT_RESET_REGISTER | ACPI_FADT_PLATFORM_CLOCK;
+	fadt->flags |= ACPI_FADT_RESET_REGISTER | ACPI_FADT_PLATFORM_CLOCK;
 
 	/* PM1 Status: ACPI 4.8.3.1.1 */
 	fadt->pm1a_evt_blk = pmbase + R_QNC_PM1BLK_PM1S;
diff --git a/src/soc/intel/skylake/fadt.c b/src/soc/intel/skylake/fadt.c
index b2f72e5f0a..732f6b6bf5 100644
--- a/src/soc/intel/skylake/fadt.c
+++ b/src/soc/intel/skylake/fadt.c
@@ -46,7 +46,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	if (!CONFIG(NO_FADT_8042))
 		fadt->iapc_boot_arch |= ACPI_FADT_8042;
 
-	fadt->flags = ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
+	fadt->flags |= ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
 			ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
 			ACPI_FADT_RESET_REGISTER | ACPI_FADT_SEALED_CASE |
 			ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;
diff --git a/src/soc/intel/xeon_sp/cpx/acpi.c b/src/soc/intel/xeon_sp/cpx/acpi.c
index b595e02390..db233cbca5 100644
--- a/src/soc/intel/xeon_sp/cpx/acpi.c
+++ b/src/soc/intel/xeon_sp/cpx/acpi.c
@@ -298,7 +298,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->duty_offset = 1;
 	fadt->day_alrm = 0xd;
 
-	fadt->flags = ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED | ACPI_FADT_C2_MP_SUPPORTED |
+	fadt->flags |= ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED | ACPI_FADT_C2_MP_SUPPORTED |
 			ACPI_FADT_RESET_REGISTER | ACPI_FADT_PLATFORM_CLOCK;
 
 	fadt->reset_reg.space_id = 1;
diff --git a/src/soc/intel/xeon_sp/skx/acpi.c b/src/soc/intel/xeon_sp/skx/acpi.c
index cdc89d0939..13bddfc3bb 100644
--- a/src/soc/intel/xeon_sp/skx/acpi.c
+++ b/src/soc/intel/xeon_sp/skx/acpi.c
@@ -263,10 +263,10 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->century = 0x00;
 	fadt->iapc_boot_arch = ACPI_FADT_LEGACY_DEVICES | ACPI_FADT_8042;
 
-	fadt->flags = ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
-		      ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
-		      ACPI_FADT_RESET_REGISTER | ACPI_FADT_SLEEP_TYPE |
-		      ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;
+	fadt->flags |= ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
+		       ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
+		       ACPI_FADT_RESET_REGISTER | ACPI_FADT_SLEEP_TYPE |
+		       ACPI_FADT_S4_RTC_WAKE | ACPI_FADT_PLATFORM_CLOCK;
 
 	/* Reset Register */
 	fadt->reset_reg.space_id = ACPI_ADDRESS_SPACE_IO;