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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt10
-rw-r--r--drivers/acpi/internal.h1
-rw-r--r--drivers/acpi/scan.c1
-rw-r--r--drivers/acpi/sysfs.c56
4 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 21e2d8863705..d1eec5ed1134 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -106,6 +106,16 @@
use by PCI
Format: <irq>,<irq>...
+ acpi_mask_gpe= [HW,ACPI]
+ Due to the existence of _Lxx/_Exx, some GPEs triggered
+ by unsupported hardware/firmware features can result in
+ GPE floodings that cannot be automatically disabled by
+ the GPE dispatcher.
+ 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
AML control methods that contain the opcodes to create
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 1b41a2739dac..0c452265c111 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -37,6 +37,7 @@ void acpi_amba_init(void);
static inline void acpi_amba_init(void) {}
#endif
int acpi_sysfs_init(void);
+void acpi_gpe_apply_masked_gpes(void);
void acpi_container_init(void);
void acpi_memory_hotplug_init(void);
#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 45dec874ea55..192691880d55 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2074,6 +2074,7 @@ int __init acpi_scan_init(void)
}
}
+ acpi_gpe_apply_masked_gpes();
acpi_update_all_gpes();
acpi_ec_ecdt_start();
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
index 703c26e7022c..cf05ae973381 100644
--- a/drivers/acpi/sysfs.c
+++ b/drivers/acpi/sysfs.c
@@ -708,6 +708,62 @@ end:
return result ? result : size;
}
+/*
+ * A Quirk Mechanism for GPE Flooding Prevention:
+ *
+ * Quirks may be needed to prevent GPE flooding on a specific GPE. The
+ * flooding typically cannot be detected and automatically prevented by
+ * ACPI_GPE_DISPATCH_NONE check because there is a _Lxx/_Exx prepared in
+ * the AML tables. This normally indicates a feature gap in Linux, thus
+ * instead of providing endless quirk tables, we provide a boot parameter
+ * for those who want this quirk. For example, if the users want to prevent
+ * the GPE flooding for GPE 00, they need to specify the following boot
+ * parameter:
+ * acpi_mask_gpe=0x00
+ * The masking status can be modified by the following runtime controlling
+ * 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;
+
+static int __init acpi_gpe_set_masked_gpes(char *val)
+{
+ u8 gpe;
+
+ if (kstrtou8(val, 0, &gpe) || gpe > ACPI_MASKABLE_GPE_MAX)
+ return -EINVAL;
+ acpi_masked_gpes |= ((u64)1<<gpe);
+
+ return 1;
+}
+__setup("acpi_mask_gpe=", acpi_gpe_set_masked_gpes);
+
+void __init acpi_gpe_apply_masked_gpes(void)
+{
+ acpi_handle handle;
+ 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);
+ }
+ }
+ }
+}
+
void acpi_irq_stats_init(void)
{
acpi_status status;