diff mbox

[09/21] FADT: expand the compliance test for FIRMWARE_CTRL fields

Message ID 1454981583-31872-10-git-send-email-al.stone@linaro.org
State Superseded
Headers show

Commit Message

Al Stone Feb. 9, 2016, 1:32 a.m. UTC
Expand the testing of the FIRMWARE_CTRL -- and by extension, the
X_FIRMWARE_CTRL field -- to check for full compliance with the
spec.  Only one or the other may be used at any one time, per 6.1,
but we also have to acknowledge there are tables that do use both
the 32- and 64-bit values.  At that point, we re-use parts of the
existing test to verify that they are at least consistent.

Signed-off-by: Al Stone <al.stone@linaro.org>

---
 src/acpi/fadt/fadt.c | 146 +++++++++++++++++++++++++++++++++------------------
 1 file changed, 95 insertions(+), 51 deletions(-)

-- 
2.5.0
diff mbox

Patch

diff --git a/src/acpi/fadt/fadt.c b/src/acpi/fadt/fadt.c
index 6e5ee26..84f4e09 100644
--- a/src/acpi/fadt/fadt.c
+++ b/src/acpi/fadt/fadt.c
@@ -192,61 +192,105 @@  static int fadt_revision(fwts_framework *fw)
 	return FWTS_OK;
 }
 
-
-static void acpi_table_check_fadt_firmware_control(
-	fwts_framework *fw,
-	const fwts_acpi_table_fadt *fadt,
-	bool *passed)
+static void acpi_table_check_fadt_firmware_ctrl(fwts_framework *fw)
 {
-	if (fadt->firmware_control == 0) {
-		if (fadt->header.length >= 140) {
-			if ((fadt->x_firmware_ctrl == 0) &&
-			    !(fwts_acpi_is_reduced_hardware(fadt))) {
-				*passed = false;
-				fwts_failed(fw, LOG_LEVEL_CRITICAL,
-					"FADTFACSZero",
-					"FADT 32 bit FIRMWARE_CONTROL and "
-					"64 bit X_FIRMWARE_CONTROL (FACS "
-					"address) are null.");
-				fwts_advice(fw,
-					"The 32 bit FIRMWARE_CTRL or 64 "
-					"bit X_FIRMWARE_CTRL should point "
-					"to a valid Firmware ACPI Control "
-					"Structure (FACS) when ACPI hardware "
-					"reduced mode is not set. ");
-			}
+	/* tests for very old FADTs */
+	if (fadt->header.length < 140 && fadt->firmware_control == 0) {
+		fwts_failed(fw, LOG_LEVEL_MEDIUM,
+			    "FADT32BitFACSNull",
+			    "FADT 32 bit FIRMWARE_CONTROL is null.");
+		fwts_advice(fw,
+			    "The ACPI version 1.0 FADT has a NULL "
+			    "FIRMWARE_CTRL and it needs to be defined "
+			    "to point to a valid Firmware ACPI Control "
+			    "Structure (FACS).");
+
+		/* can't do much else */
+		return;
+	}
+
+	/* for more recent FADTs, things get more complicated */
+	if (fadt->firmware_control == 0 && fadt->x_firmware_ctrl == 0) {
+		if (fwts_acpi_is_reduced_hardware(fadt)) {
+			fwts_passed(fw,
+				    "FADT 32 bit FIRMWARE_CONTROL and "
+				    "64 bit X_FIRMWARE_CONTROL (FACS "
+				    "address) are null in hardware reduced "
+				    "mode.");
+			fwts_advice(fw,
+				    "When in hardware reduced mode, it is "
+				    "allowed to have both the 32-bit "
+				    "FIRMWARE_CTRL and 64-bit X_FIRMWARE_CTRL "
+				    "fields set to zero as they are.  This "
+				    "indicates that no FACS is available.");
 		} else {
-			*passed = false;
-			fwts_failed(fw, LOG_LEVEL_MEDIUM,
-				"FADT32BitFACSNull",
-				"FADT 32 bit FIRMWARE_CONTROL is null.");
+			fwts_failed(fw, LOG_LEVEL_CRITICAL,
+				    "FADTFACSZero",
+				    "FADT 32 bit FIRMWARE_CONTROL and "
+				    "64 bit X_FIRMWARE_CONTROL (FACS "
+				    "address) are both null.");
 			fwts_advice(fw,
-				"The ACPI version 1.0 FADT has a NULL "
-				"FIRMWARE_CTRL and it needs to be defined "
-				"to point to a valid Firmware ACPI Control "
-				"Structure (FACS).");
+				    "The 32 bit FIRMWARE_CTRL or 64 "
+				    "bit X_FIRMWARE_CTRL should point "
+				    "to a valid Firmware ACPI Control "
+				    "Structure (FACS) when ACPI hardware "
+				    "reduced mode is not set. ");
 		}
+
+	}
+
+	if ((fadt->firmware_control != 0 && fadt->x_firmware_ctrl == 0) ||
+	    (fadt->firmware_control == 0 && fadt->x_firmware_ctrl != 0)) {
+		fwts_passed(fw,
+			    "Only one of FIRMWARE_CTRL and X_FIRMWARE_CTRL "
+			    "is non-zero.");
 	} else {
-		if (fadt->header.length >= 140) {
-			if (fadt->x_firmware_ctrl != 0) {
-				if (((uint64_t)fadt->firmware_control != fadt->x_firmware_ctrl)) {
-					*passed = false;
-					fwts_failed(fw, LOG_LEVEL_MEDIUM,
-						"FwCtrl32and64Differ",
-						"FIRMWARE_CONTROL is 0x%" PRIx32
-						" and differs from X_FIRMWARE_CONTROL "
-						"0x%" PRIx64,
-						fadt->firmware_control,
-						fadt->x_firmware_ctrl);
-					fwts_advice(fw,
-						"One would expect the 32 bit FIRMWARE_CTRL "
-						"and 64 bit X_FIRMWARE_CTRL pointers to "
-						"point to the same FACS, however they don't "
-						"which is clearly ambiguous and wrong. "
-						"The kernel works around this by using the "
-						"64 bit X_FIRMWARE_CTRL pointer to the FACS. ");
-				}
-			}
+		fwts_failed(fw, LOG_LEVEL_MEDIUM,
+			    "FADTFACSBothSet",
+			    "Both 32-bit FIRMWARE_CTRL and 64-bit "
+			    "X_FIRMWARE_CTRL pointers to the FACS are "
+			    "set but only one is allowed.");
+		fwts_advice(fw,
+			    "Having both FACS pointers set is ambiguous; "
+			    "there is no way to determine which one is "
+			    "the correct address.  The kernel workaround "
+			    "is to always use the 64-bit X_FIRMWARE_CTRL.");
+	}
+
+
+	if (fadt->firmware_control != 0 && fadt->x_firmware_ctrl != 0) {
+		if ((uint64_t)fadt->firmware_control == fadt->x_firmware_ctrl) {
+			fwts_passed(fw,
+				    "Both FIRMWARE_CTRL and X_FIRMWARE_CTRL "
+				    "are being used and contain the same FACS "
+				    "address.");
+			fwts_advice(fw,
+				    "While having FIRMWARE_CTRL and "
+				    "X_FIRMWARE_CTRL both set to an address "
+				    "is not compliant with the ACPI "
+				    "specification, they are both set to "
+				    "the same address, which at least "
+				    "mitigates the ambiguity in determining "
+				    "which address is the correct one to use "
+				    "for the FACS.  Ideally, only one of the "
+				    "two addresses should be set but as a "
+				    "practical matter, this will work.");
+		} else {
+			fwts_failed(fw, LOG_LEVEL_MEDIUM,
+				    "FwCtrl32and64Differ",
+				    "FIRMWARE_CONTROL is 0x%" PRIx32
+				    " and differs from X_FIRMWARE_CONTROL "
+				    "0x%" PRIx64,
+				    fadt->firmware_control,
+				    fadt->x_firmware_ctrl);
+			fwts_advice(fw,
+				    "One would expect the 32 bit FIRMWARE_CTRL "
+				    "and 64 bit X_FIRMWARE_CTRL pointers to "
+				    "point to the same FACS, however they do "
+				    "not which is clearly ambiguous and wrong. "
+				    "The kernel works around this by using the "
+				    "64-bit X_FIRMWARE_CTRL pointer to the "
+				    "FACS. ");
 		}
 	}
 }
@@ -486,7 +530,7 @@  static int fadt_test1(fwts_framework *fw)
 {
 	bool passed = true;
 
-	acpi_table_check_fadt_firmware_control(fw, fadt, &passed);
+	acpi_table_check_fadt_firmware_ctrl(fw);
 	acpi_table_check_fadt_dsdt(fw, fadt, &passed);
 	acpi_table_check_fadt_smi(fw, fadt, &passed);
 	acpi_table_check_fadt_pm_tmr(fw, fadt, &passed);