[PATCH v2 1/3] ACPICA: Events: Introduce acpi_mask_gpe()/acpi_unmask_gpe() to implement GPE masking mechanism

From: Lv Zheng
Date: Thu Jun 23 2016 - 02:20:31 EST


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()/acpi_unmask_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://bugs.acpica.org/show_bug.cgi?id=1102
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
drivers/acpi/acpica/acevents.h | 3 +++
drivers/acpi/acpica/aclocal.h | 2 ++
drivers/acpi/acpica/evgpe.c | 57 ++++++++++++++++++++++++++++++++++++++++
drivers/acpi/acpica/evxfgpe.c | 43 ++++++++++++++++++++++++++++++
drivers/acpi/acpica/hwgpe.c | 23 ++++++++++++----
include/acpi/acpixf.h | 4 +++
include/acpi/actypes.h | 39 ++++++++++++++-------------
7 files changed, 148 insertions(+), 23 deletions(-)

diff --git a/drivers/acpi/acpica/acevents.h b/drivers/acpi/acpica/acevents.h
index 77af91c..92fa47c 100644
--- a/drivers/acpi/acpica/acevents.h
+++ b/drivers/acpi/acpica/acevents.h
@@ -86,6 +86,9 @@ acpi_ev_update_gpe_enable_mask(struct acpi_gpe_event_info *gpe_event_info);
acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info);

acpi_status
+acpi_ev_mask_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 is_masked);
+
+acpi_status
acpi_ev_add_gpe_reference(struct acpi_gpe_event_info *gpe_event_info);

acpi_status
diff --git a/drivers/acpi/acpica/aclocal.h b/drivers/acpi/acpica/aclocal.h
index 13331d7..dff1207 100644
--- a/drivers/acpi/acpica/aclocal.h
+++ b/drivers/acpi/acpica/aclocal.h
@@ -484,6 +484,7 @@ struct acpi_gpe_event_info {
u8 flags; /* Misc info about this GPE */
u8 gpe_number; /* This GPE */
u8 runtime_count; /* References to a run GPE */
+ u8 disable_for_dispatch; /* Masked during dispatching */
};

/* Information about a GPE register pair, one per each status/enable pair in an array */
@@ -494,6 +495,7 @@ struct acpi_gpe_register_info {
u16 base_gpe_number; /* Base GPE number for this register */
u8 enable_for_wake; /* GPEs to keep enabled when sleeping */
u8 enable_for_run; /* GPEs to keep enabled when running */
+ u8 mask_for_run; /* GPEs to keep masked when running */
u8 enable_mask; /* Current mask of enabled GPEs */
};

diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c
index 4b4949c..bdb10be 100644
--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -130,6 +130,60 @@ acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)

/*******************************************************************************
*
+ * FUNCTION: acpi_ev_mask_gpe
+ *
+ * PARAMETERS: gpe_event_info - GPE to be blocked/unblocked
+ * is_masked - Whether the GPE is masked or not
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Unconditionally mask/unmask a GPE during runtime.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ev_mask_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 is_masked)
+{
+ struct acpi_gpe_register_info *gpe_register_info;
+ u32 register_bit;
+
+ ACPI_FUNCTION_TRACE(ev_mask_gpe);
+
+ gpe_register_info = gpe_event_info->register_info;
+ if (!gpe_register_info) {
+ return_ACPI_STATUS(AE_NOT_EXIST);
+ }
+
+ register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info);
+
+ /* Perform the action */
+
+ if (is_masked) {
+ if (register_bit & gpe_register_info->mask_for_run) {
+ return_ACPI_STATUS(AE_BAD_PARAMETER);
+ }
+
+ (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
+ ACPI_SET_BIT(gpe_register_info->mask_for_run, (u8)register_bit);
+ } else {
+ if (!(register_bit & gpe_register_info->mask_for_run)) {
+ return_ACPI_STATUS(AE_BAD_PARAMETER);
+ }
+
+ ACPI_CLEAR_BIT(gpe_register_info->mask_for_run,
+ (u8)register_bit);
+ if (gpe_event_info->runtime_count
+ && !gpe_event_info->disable_for_dispatch) {
+ (void)acpi_hw_low_set_gpe(gpe_event_info,
+ ACPI_GPE_ENABLE);
+ }
+ }
+
+ return_ACPI_STATUS(AE_OK);
+}
+
+/*******************************************************************************
+ *
* FUNCTION: acpi_ev_add_gpe_reference
*
* PARAMETERS: gpe_event_info - Add a reference to this GPE
@@ -674,6 +728,7 @@ acpi_status acpi_ev_finish_gpe(struct acpi_gpe_event_info *gpe_event_info)
* in the event_info.
*/
(void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_CONDITIONAL_ENABLE);
+ gpe_event_info->disable_for_dispatch = FALSE;
return (AE_OK);
}

@@ -737,6 +792,8 @@ acpi_ev_gpe_dispatch(struct acpi_namespace_node *gpe_device,
}
}

+ gpe_event_info->disable_for_dispatch = TRUE;
+
/*
* Dispatch the GPE to either an installed handler or the control
* method associated with this GPE (_Lxx or _Exx). If a handler
diff --git a/drivers/acpi/acpica/evxfgpe.c b/drivers/acpi/acpica/evxfgpe.c
index 17cfef7..d7a3b27 100644
--- a/drivers/acpi/acpica/evxfgpe.c
+++ b/drivers/acpi/acpica/evxfgpe.c
@@ -235,11 +235,13 @@ acpi_status acpi_set_gpe(acpi_handle gpe_device, u32 gpe_number, u8 action)
case ACPI_GPE_ENABLE:

status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
+ gpe_event_info->disable_for_dispatch = FALSE;
break;

case ACPI_GPE_DISABLE:

status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
+ gpe_event_info->disable_for_dispatch = TRUE;
break;

default:
@@ -257,6 +259,47 @@ ACPI_EXPORT_SYMBOL(acpi_set_gpe)

/*******************************************************************************
*
+ * FUNCTION: acpi_mask_gpe
+ *
+ * PARAMETERS: gpe_device - Parent GPE Device. NULL for GPE0/GPE1
+ * gpe_number - GPE level within the GPE block
+ * is_masked - Whether the GPE is masked or not
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Unconditionally mask/unmask the an individual GPE, ex., to
+ * prevent a GPE flooding.
+ *
+ ******************************************************************************/
+acpi_status acpi_mask_gpe(acpi_handle gpe_device, u32 gpe_number, u8 is_masked)
+{
+ struct acpi_gpe_event_info *gpe_event_info;
+ acpi_status status;
+ acpi_cpu_flags flags;
+
+ ACPI_FUNCTION_TRACE(acpi_mask_gpe);
+
+ flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
+
+ /* Ensure that we have a valid GPE number */
+
+ gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
+ if (!gpe_event_info) {
+ status = AE_BAD_PARAMETER;
+ goto unlock_and_exit;
+ }
+
+ status = acpi_ev_mask_gpe(gpe_event_info, is_masked);
+
+unlock_and_exit:
+ acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
+ return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_mask_gpe)
+
+/*******************************************************************************
+ *
* FUNCTION: acpi_mark_gpe_for_wake
*
* PARAMETERS: gpe_device - Parent GPE Device. NULL for GPE0/GPE1
diff --git a/drivers/acpi/acpica/hwgpe.c b/drivers/acpi/acpica/hwgpe.c
index bdecd5e..ccea12a 100644
--- a/drivers/acpi/acpica/hwgpe.c
+++ b/drivers/acpi/acpica/hwgpe.c
@@ -98,7 +98,7 @@ acpi_status
acpi_hw_low_set_gpe(struct acpi_gpe_event_info *gpe_event_info, u32 action)
{
struct acpi_gpe_register_info *gpe_register_info;
- acpi_status status;
+ acpi_status status = AE_OK;
u32 enable_mask;
u32 register_bit;

@@ -148,9 +148,14 @@ acpi_hw_low_set_gpe(struct acpi_gpe_event_info *gpe_event_info, u32 action)
return (AE_BAD_PARAMETER);
}

- /* Write the updated enable mask */
+ if (!(register_bit & gpe_register_info->mask_for_run)) {

- status = acpi_hw_write(enable_mask, &gpe_register_info->enable_address);
+ /* Write the updated enable mask */
+
+ status =
+ acpi_hw_write(enable_mask,
+ &gpe_register_info->enable_address);
+ }
return (status);
}

@@ -242,6 +247,12 @@ acpi_hw_get_gpe_status(struct acpi_gpe_event_info *gpe_event_info,
local_event_status |= ACPI_EVENT_FLAG_ENABLED;
}

+ /* GPE currently masked? (masked for runtime?) */
+
+ if (register_bit & gpe_register_info->mask_for_run) {
+ local_event_status |= ACPI_EVENT_FLAG_MASKED;
+ }
+
/* GPE enabled for wake? */

if (register_bit & gpe_register_info->enable_for_wake) {
@@ -397,6 +408,7 @@ acpi_hw_enable_runtime_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
u32 i;
acpi_status status;
struct acpi_gpe_register_info *gpe_register_info;
+ u32 enable_mask;

/* NOTE: assumes that all GPEs are currently disabled */

@@ -410,9 +422,10 @@ acpi_hw_enable_runtime_gpe_block(struct acpi_gpe_xrupt_info *gpe_xrupt_info,

/* Enable all "runtime" GPEs in this register */

+ enable_mask = gpe_register_info->enable_for_run &
+ ~gpe_register_info->mask_for_run;
status =
- acpi_hw_gpe_enable_write(gpe_register_info->enable_for_run,
- gpe_register_info);
+ acpi_hw_gpe_enable_write(enable_mask, gpe_register_info);
if (ACPI_FAILURE(status)) {
return (status);
}
diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index 4e4c214..7aff081 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -732,6 +732,10 @@ 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 cb389ef..fa4bd6a 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
--
1.7.10