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ACPICA: Events: Remove acpi_ev_valid_gpe_event() due to current restr…
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…iction

ACPICA commit 8823b44ff53859ab24ecfcfd3fba8cc56b17d223

Currently we rely on the logic that GPE blocks will never be deleted,
otherwise we can be broken by the race between acpi_ev_create_gpe_block(),
acpi_ev_delete_gpe_block() and acpi_ev_gpe_detect().
On the other hand, if we want to protect GPE block creation/deletion, we
need to use a different synchronization facility to protect the period
between acpi_ev_gpe_dispatch() and acpi_ev_asynch_enable_gpe(). Which leaves us
no choice but abandoning the ACPI_MTX_EVENTS used during this period.

This patch removes ACPI_MTX_EVENTS used during this period and the
acpi_ev_valid_gpe_event() to reflect current restriction. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/8823b44f
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Lv Zheng authored and Rafael J. Wysocki committed Feb 5, 2015
1 parent 833bb93 commit b18da58
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Showing 3 changed files with 15 additions and 100 deletions.
2 changes: 0 additions & 2 deletions drivers/acpi/acpica/acevents.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -143,8 +143,6 @@ acpi_ev_match_gpe_method(acpi_handle obj_handle,
acpi_status
acpi_ev_walk_gpe_list(acpi_gpe_callback gpe_walk_callback, void *context);

u8 acpi_ev_valid_gpe_event(struct acpi_gpe_event_info *gpe_event_info);

acpi_status
acpi_ev_get_gpe_device(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
struct acpi_gpe_block_info *gpe_block, void *context);
Expand Down
62 changes: 13 additions & 49 deletions drivers/acpi/acpica/evgpe.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -474,51 +474,14 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
{
struct acpi_gpe_event_info *gpe_event_info = context;
acpi_status status;
struct acpi_gpe_event_info *local_gpe_event_info;
struct acpi_evaluate_info *info;
struct acpi_gpe_notify_info *notify;

ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);

/* Allocate a local GPE block */

local_gpe_event_info =
ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_event_info));
if (!local_gpe_event_info) {
ACPI_EXCEPTION((AE_INFO, AE_NO_MEMORY, "while handling a GPE"));
return_VOID;
}

status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
if (ACPI_FAILURE(status)) {
ACPI_FREE(local_gpe_event_info);
return_VOID;
}

/* Must revalidate the gpe_number/gpe_block */

if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
ACPI_FREE(local_gpe_event_info);
return_VOID;
}

/*
* Take a snapshot of the GPE info for this level - we copy the info to
* prevent a race condition with remove_handler/remove_block.
*/
ACPI_MEMCPY(local_gpe_event_info, gpe_event_info,
sizeof(struct acpi_gpe_event_info));

status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
if (ACPI_FAILURE(status)) {
ACPI_FREE(local_gpe_event_info);
return_VOID;
}

/* Do the correct dispatch - normal method or implicit notify */

switch (local_gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
case ACPI_GPE_DISPATCH_NOTIFY:
/*
* Implicit notify.
Expand All @@ -531,7 +494,7 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
* June 2012: Expand implicit notify mechanism to support
* notifies on multiple device objects.
*/
notify = local_gpe_event_info->dispatch.notify_list;
notify = gpe_event_info->dispatch.notify_list;
while (ACPI_SUCCESS(status) && notify) {
status =
acpi_ev_queue_notify_request(notify->device_node,
Expand All @@ -555,7 +518,7 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
* _Lxx/_Exx control method that corresponds to this GPE
*/
info->prefix_node =
local_gpe_event_info->dispatch.method_node;
gpe_event_info->dispatch.method_node;
info->flags = ACPI_IGNORE_RETURN_VALUE;

status = acpi_ns_evaluate(info);
Expand All @@ -565,25 +528,27 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"while evaluating GPE method [%4.4s]",
acpi_ut_get_node_name
(local_gpe_event_info->dispatch.
method_node)));
acpi_ut_get_node_name(gpe_event_info->
dispatch.
method_node)));
}
break;

default:

return_VOID; /* Should never happen */
goto error_exit; /* Should never happen */
}

/* Defer enabling of GPE until all notify handlers are done */

status = acpi_os_execute(OSL_NOTIFY_HANDLER,
acpi_ev_asynch_enable_gpe,
local_gpe_event_info);
if (ACPI_FAILURE(status)) {
ACPI_FREE(local_gpe_event_info);
acpi_ev_asynch_enable_gpe, gpe_event_info);
if (ACPI_SUCCESS(status)) {
return_VOID;
}

error_exit:
acpi_ev_asynch_enable_gpe(gpe_event_info);
return_VOID;
}

Expand Down Expand Up @@ -611,7 +576,6 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_enable_gpe(void *context)
(void)acpi_ev_finish_gpe(gpe_event_info);
acpi_os_release_lock(acpi_gbl_gpe_lock, flags);

ACPI_FREE(gpe_event_info);
return;
}

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51 changes: 2 additions & 49 deletions drivers/acpi/acpica/evgpeutil.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -106,53 +106,6 @@ acpi_ev_walk_gpe_list(acpi_gpe_callback gpe_walk_callback, void *context)
return_ACPI_STATUS(status);
}

/*******************************************************************************
*
* FUNCTION: acpi_ev_valid_gpe_event
*
* PARAMETERS: gpe_event_info - Info for this GPE
*
* RETURN: TRUE if the gpe_event is valid
*
* DESCRIPTION: Validate a GPE event. DO NOT CALL FROM INTERRUPT LEVEL.
* Should be called only when the GPE lists are semaphore locked
* and not subject to change.
*
******************************************************************************/

u8 acpi_ev_valid_gpe_event(struct acpi_gpe_event_info *gpe_event_info)
{
struct acpi_gpe_xrupt_info *gpe_xrupt_block;
struct acpi_gpe_block_info *gpe_block;

ACPI_FUNCTION_ENTRY();

/* No need for spin lock since we are not changing any list elements */

/* Walk the GPE interrupt levels */

gpe_xrupt_block = acpi_gbl_gpe_xrupt_list_head;
while (gpe_xrupt_block) {
gpe_block = gpe_xrupt_block->gpe_block_list_head;

/* Walk the GPE blocks on this interrupt level */

while (gpe_block) {
if ((&gpe_block->event_info[0] <= gpe_event_info) &&
(&gpe_block->event_info[gpe_block->gpe_count] >
gpe_event_info)) {
return (TRUE);
}

gpe_block = gpe_block->next;
}

gpe_xrupt_block = gpe_xrupt_block->next;
}

return (FALSE);
}

/*******************************************************************************
*
* FUNCTION: acpi_ev_get_gpe_device
Expand All @@ -167,8 +120,8 @@ u8 acpi_ev_valid_gpe_event(struct acpi_gpe_event_info *gpe_event_info)
******************************************************************************/

acpi_status
acpi_ev_get_gpe_device(struct acpi_gpe_xrupt_info * gpe_xrupt_info,
struct acpi_gpe_block_info * gpe_block, void *context)
acpi_ev_get_gpe_device(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
struct acpi_gpe_block_info *gpe_block, void *context)
{
struct acpi_gpe_device_info *info = context;

Expand Down

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