ACPICA: Events: Introduce acpi_mask_gpe() to implement GPE masking mechanism

ACPICA commit 23a417ca406a527e7ae1710893e59a8b6db30e14

There is a facility in Linux, developers can control the enabling/disabling
of a GPE via /sys/firmware/acpi/interrupts/gpexx. This is mainly for
debugging purposes.

But many users expect to use this facility to implement quirks to mask a
specific GPE when there is a gap in Linux causing this GPE to flood. This
is not working correctly because currently this facility invokes
enabling/disabling counting based GPE driver APIs:
 acpi_enable_gpe()/acpi_disable_gpe()
and the GPE drivers can still affect the count to mess up the GPE
masking purposes.

However, most of the IRQ chip designs allow masking/unmasking IRQs via a
masking bit which is different from the enabled bit to achieve the same
purpose. But the GPE hardware doesn't contain such a feature, this brings
the trouble.

In this patch, we introduce a software mechanism to implement the GPE
masking feature, and acpi_mask_gpe() are provided to the OSPMs to
mask/unmask GPEs in the above mentioned situation instead of
acpi_enable_gpe()/acpi_disable_gpe(). ACPICA BZ 1102. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/23a417ca
Link: https://bugs.acpica.org/show_bug.cgi?id=1102
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>

2 files changed, 25 insertions, 18 deletions

diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index 875964dea539..c2d4b9c9f8a4 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -736,6 +736,10 @@ ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_status
 						u32 gpe_number))
 
 ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_status
+				acpi_mask_gpe(acpi_handle gpe_device,
+					      u32 gpe_number, u8 is_masked))
+
+ACPI_HW_DEPENDENT_RETURN_STATUS(acpi_status
 				acpi_mark_gpe_for_wake(acpi_handle gpe_device,
 						       u32 gpe_number))
 
diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index cb389efd321c..fa4bd6ad5d24 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -732,16 +732,17 @@ typedef u32 acpi_event_type;
  * The encoding of acpi_event_status is illustrated below.
  * Note that a set bit (1) indicates the property is TRUE
  * (e.g. if bit 0 is set then the event is enabled).
- * +-------------+-+-+-+-+-+
- * |   Bits 31:5 |4|3|2|1|0|
- * +-------------+-+-+-+-+-+
- *          |     | | | | |
- *          |     | | | | +- Enabled?
- *          |     | | | +--- Enabled for wake?
- *          |     | | +----- Status bit set?
- *          |     | +------- Enable bit set?
- *          |     +--------- Has a handler?
- *          +--------------- <Reserved>
+ * +-------------+-+-+-+-+-+-+
+ * |   Bits 31:6 |5|4|3|2|1|0|
+ * +-------------+-+-+-+-+-+-+
+ *          |     | | | | | |
+ *          |     | | | | | +- Enabled?
+ *          |     | | | | +--- Enabled for wake?
+ *          |     | | | +----- Status bit set?
+ *          |     | | +------- Enable bit set?
+ *          |     | +--------- Has a handler?
+ *          |     +----------- Masked?
+ *          +----------------- <Reserved>
  */
 typedef u32 acpi_event_status;
 
@@ -751,6 +752,7 @@ typedef u32 acpi_event_status;
 #define ACPI_EVENT_FLAG_STATUS_SET      (acpi_event_status) 0x04
 #define ACPI_EVENT_FLAG_ENABLE_SET      (acpi_event_status) 0x08
 #define ACPI_EVENT_FLAG_HAS_HANDLER     (acpi_event_status) 0x10
+#define ACPI_EVENT_FLAG_MASKED          (acpi_event_status) 0x20
 #define ACPI_EVENT_FLAG_SET             ACPI_EVENT_FLAG_STATUS_SET
 
 /* Actions for acpi_set_gpe, acpi_gpe_wakeup, acpi_hw_low_set_gpe */
@@ -761,14 +763,15 @@ typedef u32 acpi_event_status;
 
 /*
  * GPE info flags - Per GPE
- * +-------+-+-+---+
- * |  7:5  |4|3|2:0|
- * +-------+-+-+---+
- *     |    | |  |
- *     |    | |  +-- Type of dispatch:to method, handler, notify, or none
- *     |    | +----- Interrupt type: edge or level triggered
- *     |    +------- Is a Wake GPE
- *     +------------ <Reserved>
+ * +---+-+-+-+---+
+ * |7:6|5|4|3|2:0|
+ * +---+-+-+-+---+
+ *   |  | | |  |
+ *   |  | | |  +-- Type of dispatch:to method, handler, notify, or none
+ *   |  | | +----- Interrupt type: edge or level triggered
+ *   |  | +------- Is a Wake GPE
+ *   |  +--------- Is GPE masked by the software GPE masking machanism
+ *   +------------ <Reserved>
  */
 #define ACPI_GPE_DISPATCH_NONE          (u8) 0x00
 #define ACPI_GPE_DISPATCH_METHOD        (u8) 0x01