ACPICA: Tables: Enable both 32-bit and 64-bit FACS

ACPICA commit f7b86f35416e3d1f71c3d816ff5075ddd33ed486

The following commit is reported to have broken s2ram on some platforms:
 Commit: 0249ed2444d65d65fc3f3f64f398f1ad0b7e54cd
 ACPICA: Add option to favor 32-bit FADT addresses.
The platform reports 2 FACS tables (which is not allowed by ACPI
specification) and the new 32-bit address favor rule forces OSPMs to use
the FACS table reported via FADT's X_FIRMWARE_CTRL field.

The root cause of the reported bug might be one of the followings:
1. BIOS may favor the 64-bit firmware waking vector address when the
   version of the FACS is greater than 0 and Linux currently only supports
   resuming from the real mode, so the 64-bit firmware waking vector has
   never been set and might be invalid to BIOS while the commit enables
   higher version FACS.
2. BIOS may favor the FACS reported via the "FIRMWARE_CTRL" field in the
   FADT while the commit doesn't set the firmware waking vector address of
   the FACS reported by "FIRMWARE_CTRL", it only sets the firware waking
   vector address of the FACS reported by "X_FIRMWARE_CTRL".

This patch excludes the cases that can trigger the bugs caused by the root
cause 2.

There is no handshaking mechanism can be used by OSPM to tell BIOS which
FACS is currently used. Thus the FACS reported by "FIRMWARE_CTRL" may still
be used by BIOS and the 0 value of the 32-bit firmware waking vector might
trigger such failure.

This patch tries to favor 32bit FACS address in another way where both the
FACS reported by "FIRMWARE_CTRL" and the FACS reported by "X_FIRMWARE_CTRL"
are loaded so that further commit can set firmware waking vector in the
both tables to ensure we can exclude the cases that trigger the bugs caused
by the root cause 2. The exclusion is split into 2 commits as this commit
is also useful for dumping more ACPI tables, it won't get reverted when
such exclusion is no longer necessary. Lv Zheng.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=74021
Link: https://github.com/acpica/acpica/commit/f7b86f35
Cc: 3.14.1+ <stable@vger.kernel.org> # 3.14.1+
Reported-and-tested-by: Oswald Buddenhagen <ossi@kde.org>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 23 insertions, 11 deletions

diff --git a/drivers/acpi/acpica/tbutils.c b/drivers/acpi/acpica/tbutils.c
index 6559a58439c5..2fb1afaacc6d 100644
--- a/drivers/acpi/acpica/tbutils.c
+++ b/drivers/acpi/acpica/tbutils.c
@@ -68,7 +68,8 @@ acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size);
 
 acpi_status acpi_tb_initialize_facs(void)
 {
-	acpi_status status;
+	struct acpi_table_facs *facs32;
+	struct acpi_table_facs *facs64;
 
 	/* If Hardware Reduced flag is set, there is no FACS */
 
@@ -77,11 +78,22 @@ acpi_status acpi_tb_initialize_facs(void)
 		return (AE_OK);
 	}
 
-	status = acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
-					 ACPI_CAST_INDIRECT_PTR(struct
-								acpi_table_header,
-								&acpi_gbl_FACS));
-	return (status);
+	(void)acpi_get_table_by_index(ACPI_TABLE_INDEX_FACS,
+				      ACPI_CAST_INDIRECT_PTR(struct
+							     acpi_table_header,
+							     &facs32));
+	(void)acpi_get_table_by_index(ACPI_TABLE_INDEX_X_FACS,
+				      ACPI_CAST_INDIRECT_PTR(struct
+							     acpi_table_header,
+							     &facs64));
+
+	if (acpi_gbl_use32_bit_facs_addresses) {
+		acpi_gbl_FACS = facs32 ? facs32 : facs64;
+	} else {
+		acpi_gbl_FACS = facs64 ? facs64 : facs32;
+	}
+
+	return (AE_OK);
 }
 #endif				/* !ACPI_REDUCED_HARDWARE */
 
@@ -101,7 +113,7 @@ acpi_status acpi_tb_initialize_facs(void)
 u8 acpi_tb_tables_loaded(void)
 {
 
-	if (acpi_gbl_root_table_list.current_table_count >= 3) {
+	if (acpi_gbl_root_table_list.current_table_count >= 4) {
 		return (TRUE);
 	}
 
@@ -357,11 +369,11 @@ acpi_status __init acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
 	table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header));
 
 	/*
-	 * First two entries in the table array are reserved for the DSDT
-	 * and FACS, which are not actually present in the RSDT/XSDT - they
-	 * come from the FADT
+	 * First three entries in the table array are reserved for the DSDT
+	 * and 32bit/64bit FACS, which are not actually present in the
+	 * RSDT/XSDT - they come from the FADT
 	 */
-	acpi_gbl_root_table_list.current_table_count = 2;
+	acpi_gbl_root_table_list.current_table_count = 3;
 
 	/* Initialize the root table array from the RSDT/XSDT */