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authorLv Zheng <lv.zheng@intel.com>2017-04-04 19:32:17 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-04-12 12:41:18 +0200
commitc1e94148f93c4319a1aea4ae29835cd1e2017ff9 (patch)
treecd59abdd479e707ca6683ab4c017748cfa951d8f
parent43cfff65c989c0ef722bfcd2335b07a48e09aab9 (diff)
ACPI / sysfs: Provide quirk mechanism to prevent GPE flooding
[ Upstream commit 9c4aa1eecb48cfac18ed5e3aca9d9ae58fbafc11 ] Sometimes, the users may require a quirk to be provided from ACPI subsystem core to prevent a GPE from flooding. Normally, if a GPE cannot be dispatched, ACPICA core automatically prevents the GPE from firing. But there are cases the GPE is dispatched by _Lxx/_Exx provided via AML table, and OSPM is lacking of the knowledge to get _Lxx/_Exx correctly executed to handle the GPE, thus the GPE flooding may still occur. The existing quirk mechanism can be enabled/disabled using the following commands to prevent such kind of GPE flooding during runtime: # echo mask > /sys/firmware/acpi/interrupts/gpe00 # echo unmask > /sys/firmware/acpi/interrupts/gpe00 To avoid GPE flooding during boot, we need a boot stage mechanism. This patch provides such a boot stage quirk mechanism to stop this kind of GPE flooding. This patch doesn't fix any feature gap but since the new feature gaps could be found in the future endlessly, and can disappear if the feature gaps are filled, providing a boot parameter rather than a DMI table should suffice. Link: https://bugzilla.kernel.org/show_bug.cgi?id=53071 Link: https://bugzilla.kernel.org/show_bug.cgi?id=117481 Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/887793 Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--Documentation/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/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 65b05ba6ef98..a6fadef92d6d 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -305,6 +305,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
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 3d1856f1f4d0..5a2fdf156ec9 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2044,6 +2044,7 @@ 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;