[S] Change in coreboot[master]: acpi: Add a runtime method to override exposed _Sx sleep states

[Arthur Heymans (Code Review)]

Attention is currently required from: Lance Zhao, Tim Wawrzynczak.

Arthur Heymans has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/74762 )

Change subject: acpi: Add a runtime method to override exposed _Sx sleep states
......................................................................

acpi: Add a runtime method to override exposed _Sx sleep states

This allows mainboards to override available sleep states at runtime. This is
done by adding a IntObj in SSDT that DSDT consumes to override the available _Sx
states.

Signed-off-by: Arthur Heymans 
Change-Id: Ic21830c1ef9c183b1e3005cc1f8b7daf7e9ea998
---
M src/acpi/Kconfig
M src/acpi/acpi.c
M src/include/acpi/acpi.h
M src/southbridge/intel/common/acpi/sleepstates.asl
4 files changed, 41 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/62/74762/1

diff --git a/src/acpi/Kconfig b/src/acpi/Kconfig
index 5af8b22..236bb9f 100644
--- a/src/acpi/Kconfig
+++ b/src/acpi/Kconfig
@@ -61,3 +61,10 @@
    depends on HAVE_ACPI_TABLES
    help
      Selected by platforms that support and fill Intel Low Power Idle Table.
+
+config OVERRIDE_ENABLED_SLEEP_STATES
+	bool
+	depends on HAVE_ACPI_TABLES
+	help
+	  Select this on platforms that want a way to override the enabled
+	  _Sx states during runtime.
diff --git a/src/acpi/acpi.c b/src/acpi/acpi.c
index 492d043..38b1b63 100644
--- a/src/acpi/acpi.c
+++ b/src/acpi/acpi.c
@@ -517,6 +517,20 @@
    acpigen_pop_len();
 }

+void acpi_ssdt_override_sleep_states(bool enable_s1, bool enable_s2, bool enable_s3, bool enable_s4)
+{
+	assert(CONFIG(OVERRIDE_ENABLED_SLEEP_STATES));
+	assert(!(enable_s1 && CONFIG(PLATFORM_LACKS_ACPI_S1)));
+	assert(!(enable_s3 && !CONFIG(HAVE_ACPI_RESUME)));
+	assert(!(enable_s4 && CONFIG(DISABLE_ACPI_HIBERNATE)));
+
+	acpigen_write_scope("\");
+	uint32_t sleep_enable = (enable_s1 << 0) | (enable_s2 << 1)
+		| (enable_s3 << 2) | (enable_s4 << 3);
+	acpigen_write_name_dword("OSFG", sleep_enable);
+	acpigen_pop_len();
+}
+
 void acpi_create_ssdt_generator(acpi_header_t *ssdt, const char *oem_table_id)
 {
    unsigned long current = (unsigned long)ssdt + sizeof(acpi_header_t);
diff --git a/src/include/acpi/acpi.h b/src/include/acpi/acpi.h
index 77f73ae..1aa195c 100644
--- a/src/include/acpi/acpi.h
+++ b/src/include/acpi/acpi.h
@@ -1308,6 +1308,7 @@
 unsigned long write_acpi_tables(unsigned long addr);
 unsigned long acpi_fill_madt(unsigned long current);
 unsigned long acpi_fill_ivrs_ioapic(acpi_ivrs_t *ivrs, unsigned long current);
+void acpi_ssdt_override_sleep_states(bool enable_s1, bool enable_s2, bool enable_s3, bool enable_s4);
 void acpi_create_ssdt_generator(acpi_header_t *ssdt, const char *oem_table_id);
 void acpi_write_bert(acpi_bert_t *bert, uintptr_t region, size_t length);
 void acpi_create_fadt(acpi_fadt_t *fadt, acpi_facs_t *facs, void *dsdt);
diff --git a/src/southbridge/intel/common/acpi/sleepstates.asl b/src/southbridge/intel/common/acpi/sleepstates.asl
index baee300..5f86e79 100644
--- a/src/southbridge/intel/common/acpi/sleepstates.asl
+++ b/src/southbridge/intel/common/acpi/sleepstates.asl
@@ -15,6 +15,11 @@
    SSFG &= 0xf7
 }

+if (CONFIG(OVERRIDE_ENABLED_SLEEP_STATES)) {
+	External (\OSFG, IntObj)
+	SSFG = \OSFG
+}
+
 /* Supported sleep states: */
 Name(_S0, Package () {0x00, 0x00, 0x00, 0x00} )	/* (S0) - working state */