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acpi: Fix ACPI GPE mask kernel parameter

PATCH Applied Prarit Bhargava 2 participants 2 messages Nov 30, 2017 – Dec 16, 2017

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Documentation ACPI
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Prarit Bhargava

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#0 lore raw

PATCH 1/1 acpi: Fix ACPI GPE mask kernel parameter

The acpi_mask_gpe= kernel parameter documentation states that the range of mask is 128 GPEs (0x00 to 0x7F). The acpi_masked_gpes mask is a u64 so only 64 GPEs (0x00 to 0x3F) can really be masked.

Use a bitmap of size 0xFF instead of a u64 for the GPE mask so 256 GPEs can be masked.

Fixes 9c4aa1eecb48 ("ACPI / sysfs: Provide quirk mechanism to prevent GPE flooding")
Signed-off-by Prarit Bharava <[email protected]>
Cc Lv Zheng <[email protected]>
Cc Jonathan Corbet <[email protected]>
Cc "Rafael J. Wysocki" <[email protected]>
Cc [email protected]
---
 Documentation/admin-guide/kernel-parameters.txt |  1 -
 drivers/acpi/sysfs.c                            | 26 ++++++++-----------------
 2 files changed, 8 insertions(+), 19 deletions(-)
Documentation/admin-guide/kernel-parameters.txt +0 -1
index 6571fbfdb2a1..89ba74761180 100644
@@ -114,7 +114,6 @@
 			This facility can be used to prevent such uncontrolled
 			GPE floodings.
 			Format: <int>
-			Support masking of GPEs numbered from 0x00 to 0x7f.
 
 	acpi_no_auto_serialize	[HW,ACPI]
 			Disable auto-serialization of AML methods
drivers/acpi/sysfs.c +8 -18
index 06a150bb35bf..4fc59c3bc673 100644
@@ -816,14 +816,8 @@ static ssize_t counter_set(struct kobject *kobj,
  * interface:
  *   echo unmask > /sys/firmware/acpi/interrupts/gpe00
  */
-
-/*
- * Currently, the GPE flooding prevention only supports to mask the GPEs
- * numbered from 00 to 7f.
- */
-#define ACPI_MASKABLE_GPE_MAX	0x80
-
-static u64 __initdata acpi_masked_gpes;
+#define ACPI_MASKABLE_GPE_MAX	0xFF
+static DECLARE_BITMAP(acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) __initdata;
 
 static int __init acpi_gpe_set_masked_gpes(char *val)
 {

@@ -831,7 +825,7 @@ static int __init acpi_gpe_set_masked_gpes(char *val)
 
 	if (kstrtou8(val, 0, &gpe) || gpe > ACPI_MASKABLE_GPE_MAX)
 		return -EINVAL;
-	acpi_masked_gpes |= ((u64)1<<gpe);
+	set_bit(gpe, acpi_masked_gpes_map);
 
 	return 1;
 }

@@ -843,15 +837,11 @@ void __init acpi_gpe_apply_masked_gpes(void)
 	acpi_status status;
 	u8 gpe;
 
-	for (gpe = 0;
-	     gpe < min_t(u8, ACPI_MASKABLE_GPE_MAX, acpi_current_gpe_count);
-	     gpe++) {
-		if (acpi_masked_gpes & ((u64)1<<gpe)) {
-			status = acpi_get_gpe_device(gpe, &handle);
-			if (ACPI_SUCCESS(status)) {
-				pr_info("Masking GPE 0x%x.\n", gpe);
-				(void)acpi_mask_gpe(handle, gpe, TRUE);
-			}
+	for_each_set_bit(gpe, acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) {
+		status = acpi_get_gpe_device(gpe, &handle);
+		if (ACPI_SUCCESS(status)) {
+			pr_info("Masking GPE 0x%x.\n", gpe);
+			(void)acpi_mask_gpe(handle, gpe, TRUE);
 		}
 	}
 }
Signature · 1 line
2.15.0.rc0.39.g2f0e14e64
Applied
#1 lore raw
Quoted 72 lines · CET Prarit Bhargava

The acpi_mask_gpe= kernel parameter documentation states that the range of mask is 128 GPEs (0x00 to 0x7F). The acpi_masked_gpes mask is a u64 so only 64 GPEs (0x00 to 0x3F) can really be masked.

Use a bitmap of size 0xFF instead of a u64 for the GPE mask so 256 GPEs can be masked.

Fixes 9c4aa1eecb48 ("ACPI / sysfs: Provide quirk mechanism to prevent GPE flooding")
Signed-off-by Prarit Bharava <[email protected]>
Cc Lv Zheng <[email protected]>
Cc Jonathan Corbet <[email protected]>
Cc "Rafael J. Wysocki" <[email protected]>
Cc [email protected]
---
 Documentation/admin-guide/kernel-parameters.txt |  1 -
 drivers/acpi/sysfs.c                            | 26 ++++++++-----------------
 2 files changed, 8 insertions(+), 19 deletions(-)
Documentation/admin-guide/kernel-parameters.txt +0 -1
index 6571fbfdb2a1..89ba74761180 100644
@@ -114,7 +114,6 @@
 			This facility can be used to prevent such uncontrolled
 			GPE floodings.
 			Format: <int>
-			Support masking of GPEs numbered from 0x00 to 0x7f.
 
 	acpi_no_auto_serialize	[HW,ACPI]
 			Disable auto-serialization of AML methods
drivers/acpi/sysfs.c +3 -16
index 06a150bb35bf..4fc59c3bc673 100644
@@ -816,14 +816,8 @@ static ssize_t counter_set(struct kobject *kobj,
  * interface:
  *   echo unmask > /sys/firmware/acpi/interrupts/gpe00
  */
-
-/*
- * Currently, the GPE flooding prevention only supports to mask the GPEs
- * numbered from 00 to 7f.
- */
-#define ACPI_MASKABLE_GPE_MAX	0x80
-
-static u64 __initdata acpi_masked_gpes;
+#define ACPI_MASKABLE_GPE_MAX	0xFF
+static DECLARE_BITMAP(acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) __initdata;
 
 static int __init acpi_gpe_set_masked_gpes(char *val)
 {

@@ -831,7 +825,7 @@ static int __init acpi_gpe_set_masked_gpes(char *val)
 
 	if (kstrtou8(val, 0, &gpe) || gpe > ACPI_MASKABLE_GPE_MAX)
 		return -EINVAL;
-	acpi_masked_gpes |= ((u64)1<<gpe);
+	set_bit(gpe, acpi_masked_gpes_map);
 
 	return 1;
 }

@@ -843,15 +837,11 @@ void __init acpi_gpe_apply_masked_gpes(void)
 	acpi_status status;
 	u8 gpe;
 
-	for (gpe = 0;
-	     gpe < min_t(u8, ACPI_MASKABLE_GPE_MAX, acpi_current_gpe_count);
-	     gpe++) {
-		if (acpi_masked_gpes & ((u64)1<<gpe)) {
-			status = acpi_get_gpe_device(gpe, &handle);
-			if (ACPI_SUCCESS(status)) {
-				pr_info("Masking GPE 0x%x.\n", gpe);

drivers/acpi/sysfs.c void __init acpi_gpe_apply_masked_gpes(void) · line 847

Quoted 10 lines
drivers/acpi/sysfs.c +5 -2
-				(void)acpi_mask_gpe(handle, gpe, TRUE);
-			}
+	for_each_set_bit(gpe, acpi_masked_gpes_map, ACPI_MASKABLE_GPE_MAX) {
+		status = acpi_get_gpe_device(gpe, &handle);
+		if (ACPI_SUCCESS(status)) {
+			pr_info("Masking GPE 0x%x.\n", gpe);
+			(void)acpi_mask_gpe(handle, gpe, TRUE);
 		}
 	}
 }

Applied, thanks!