linux/drivers/acpi/acpica/evgpeutil.c

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// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: evgpeutil - GPE utilities
*
* Copyright (C) 2000 - 2019, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acevents.h"
#define _COMPONENT ACPI_EVENTS
ACPI_MODULE_NAME("evgpeutil")
#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
/*******************************************************************************
*
* FUNCTION: acpi_ev_walk_gpe_list
*
* PARAMETERS: gpe_walk_callback - Routine called for each GPE block
* context - Value passed to callback
*
* RETURN: Status
*
* DESCRIPTION: Walk the GPE lists.
*
******************************************************************************/
acpi_status
acpi_ev_walk_gpe_list(acpi_gpe_callback gpe_walk_callback, void *context)
{
struct acpi_gpe_block_info *gpe_block;
struct acpi_gpe_xrupt_info *gpe_xrupt_info;
acpi_status status = AE_OK;
acpi_cpu_flags flags;
ACPI_FUNCTION_TRACE(ev_walk_gpe_list);
flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
/* Walk the interrupt level descriptor list */
gpe_xrupt_info = acpi_gbl_gpe_xrupt_list_head;
while (gpe_xrupt_info) {
/* Walk all Gpe Blocks attached to this interrupt level */
gpe_block = gpe_xrupt_info->gpe_block_list_head;
while (gpe_block) {
/* One callback per GPE block */
status =
gpe_walk_callback(gpe_xrupt_info, gpe_block,
context);
if (ACPI_FAILURE(status)) {
if (status == AE_CTRL_END) { /* Callback abort */
status = AE_OK;
}
goto unlock_and_exit;
}
gpe_block = gpe_block->next;
}
gpe_xrupt_info = gpe_xrupt_info->next;
}
unlock_and_exit:
acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_get_gpe_device
*
* PARAMETERS: GPE_WALK_CALLBACK
*
* RETURN: Status
*
* DESCRIPTION: Matches the input GPE index (0-current_gpe_count) with a GPE
* block device. NULL if the GPE is one of the FADT-defined GPEs.
*
******************************************************************************/
acpi_status
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;
/* Increment Index by the number of GPEs in this block */
info->next_block_base_index += gpe_block->gpe_count;
if (info->index < info->next_block_base_index) {
/*
* The GPE index is within this block, get the node. Leave the node
* NULL for the FADT-defined GPEs
*/
if ((gpe_block->node)->type == ACPI_TYPE_DEVICE) {
info->gpe_device = gpe_block->node;
}
info->status = AE_OK;
return (AE_CTRL_END);
}
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_get_gpe_xrupt_block
*
* PARAMETERS: interrupt_number - Interrupt for a GPE block
* gpe_xrupt_block - Where the block is returned
*
* RETURN: Status
*
* DESCRIPTION: Get or Create a GPE interrupt block. There is one interrupt
* block per unique interrupt level used for GPEs. Should be
* called only when the GPE lists are semaphore locked and not
* subject to change.
*
******************************************************************************/
acpi_status
acpi_ev_get_gpe_xrupt_block(u32 interrupt_number,
struct acpi_gpe_xrupt_info **gpe_xrupt_block)
{
struct acpi_gpe_xrupt_info *next_gpe_xrupt;
struct acpi_gpe_xrupt_info *gpe_xrupt;
acpi_status status;
acpi_cpu_flags flags;
ACPI_FUNCTION_TRACE(ev_get_gpe_xrupt_block);
/* No need for lock since we are not changing any list elements here */
next_gpe_xrupt = acpi_gbl_gpe_xrupt_list_head;
while (next_gpe_xrupt) {
if (next_gpe_xrupt->interrupt_number == interrupt_number) {
*gpe_xrupt_block = next_gpe_xrupt;
return_ACPI_STATUS(AE_OK);
}
next_gpe_xrupt = next_gpe_xrupt->next;
}
/* Not found, must allocate a new xrupt descriptor */
gpe_xrupt = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_xrupt_info));
if (!gpe_xrupt) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
gpe_xrupt->interrupt_number = interrupt_number;
/* Install new interrupt descriptor with spin lock */
flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
if (acpi_gbl_gpe_xrupt_list_head) {
next_gpe_xrupt = acpi_gbl_gpe_xrupt_list_head;
while (next_gpe_xrupt->next) {
next_gpe_xrupt = next_gpe_xrupt->next;
}
next_gpe_xrupt->next = gpe_xrupt;
gpe_xrupt->previous = next_gpe_xrupt;
} else {
acpi_gbl_gpe_xrupt_list_head = gpe_xrupt;
}
acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
/* Install new interrupt handler if not SCI_INT */
if (interrupt_number != acpi_gbl_FADT.sci_interrupt) {
status = acpi_os_install_interrupt_handler(interrupt_number,
acpi_ev_gpe_xrupt_handler,
gpe_xrupt);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"Could not install GPE interrupt handler at level 0x%X",
interrupt_number));
return_ACPI_STATUS(status);
}
}
*gpe_xrupt_block = gpe_xrupt;
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_delete_gpe_xrupt
*
* PARAMETERS: gpe_xrupt - A GPE interrupt info block
*
* RETURN: Status
*
* DESCRIPTION: Remove and free a gpe_xrupt block. Remove an associated
* interrupt handler if not the SCI interrupt.
*
******************************************************************************/
acpi_status acpi_ev_delete_gpe_xrupt(struct acpi_gpe_xrupt_info *gpe_xrupt)
{
acpi_status status;
acpi_cpu_flags flags;
ACPI_FUNCTION_TRACE(ev_delete_gpe_xrupt);
/* We never want to remove the SCI interrupt handler */
if (gpe_xrupt->interrupt_number == acpi_gbl_FADT.sci_interrupt) {
gpe_xrupt->gpe_block_list_head = NULL;
return_ACPI_STATUS(AE_OK);
}
/* Disable this interrupt */
status =
acpi_os_remove_interrupt_handler(gpe_xrupt->interrupt_number,
acpi_ev_gpe_xrupt_handler);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Unlink the interrupt block with lock */
flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
if (gpe_xrupt->previous) {
gpe_xrupt->previous->next = gpe_xrupt->next;
} else {
/* No previous, update list head */
acpi_gbl_gpe_xrupt_list_head = gpe_xrupt->next;
}
if (gpe_xrupt->next) {
gpe_xrupt->next->previous = gpe_xrupt->previous;
}
acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
/* Free the block */
ACPI_FREE(gpe_xrupt);
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ev_delete_gpe_handlers
*
* PARAMETERS: gpe_xrupt_info - GPE Interrupt info
* gpe_block - Gpe Block info
*
* RETURN: Status
*
* DESCRIPTION: Delete all Handler objects found in the GPE data structs.
* Used only prior to termination.
*
******************************************************************************/
acpi_status
acpi_ev_delete_gpe_handlers(struct acpi_gpe_xrupt_info *gpe_xrupt_info,
struct acpi_gpe_block_info *gpe_block,
void *context)
{
struct acpi_gpe_event_info *gpe_event_info;
struct acpi_gpe_notify_info *notify;
struct acpi_gpe_notify_info *next;
u32 i;
u32 j;
ACPI_FUNCTION_TRACE(ev_delete_gpe_handlers);
/* Examine each GPE Register within the block */
for (i = 0; i < gpe_block->register_count; i++) {
/* Now look at the individual GPEs in this byte register */
for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
gpe_event_info = &gpe_block->event_info[((acpi_size)i *
ACPI_GPE_REGISTER_WIDTH)
+ j];
ACPICA: Events: Introduce ACPI_GPE_DISPATCH_RAW_HANDLER to fix 2 issues for the current GPE APIs ACPICA commit 199cad16530a45aea2bec98e528866e20c5927e1 Since whether the GPE should be disabled/enabled/cleared should only be determined by the GPE driver's state machine: 1. GPE should be disabled if the driver wants to switch to the GPE polling mode when a GPE storm condition is indicated and should be enabled if the driver wants to switch back to the GPE interrupt mode when all of the storm conditions are cleared. The conditions should be protected by the driver's specific lock. 2. GPE should be enabled if the driver has accepted more than one request and should be disabled if the driver has completed all of the requests. The request count should be protected by the driver's specific lock. 3. GPE should be cleared either when the driver is about to handle an edge triggered GPE or when the driver has completed to handle a level triggered GPE. The handling code should be protected by the driver's specific lock. Thus the GPE enabling/disabling/clearing operations are likely to be performed with the driver's specific lock held while we currently cannot do this. This is because: 1. We have the acpi_gbl_gpe_lock held before invoking the GPE driver's handler. Driver's specific lock is likely to be held inside of the handler, thus we can see some dead lock issues due to the reversed locking order or recursive locking. In order to solve such dead lock issues, we need to unlock the acpi_gbl_gpe_lock before invoking the handler. BZ 1100. 2. Since GPE disabling/enabling/clearing should be determined by the GPE driver's state machine, we shouldn't perform such operations inside of ACPICA for a GPE handler to mess up the driver's state machine. BZ 1101. Originally this patch includes a logic to flush GPE handlers, it is dropped due to the following reasons: 1. This is a different issue; 2. Linux OSL has fixed this by flushing SCI in acpi_os_wait_events_complete(). We will pick up this topic when the Linux OSL fix turns out to be not sufficient. Note that currently the internal operations and the acpi_gbl_gpe_lock are also used by ACPI_GPE_DISPATCH_METHOD and ACPI_GPE_DISPATCH_NOTIFY. In order not to introduce regressions, we add one ACPI_GPE_DISPATCH_RAW_HANDLER type to be distiguished from ACPI_GPE_DISPATCH_HANDLER. For which the acpi_gbl_gpe_lock is unlocked before invoking the GPE handler and the internal enabling/disabling operations are bypassed to allow drivers to perform them at a proper position using the GPE APIs and ACPI_GPE_DISPATCH_RAW_HANDLER users should invoke acpi_set_gpe() instead of acpi_enable_gpe()/acpi_disable_gpe() to bypass the internal GPE clearing code in acpi_enable_gpe(). Lv Zheng. Known issues: 1. Edge-triggered GPE lost for frequent enablings On some buggy silicon platforms, GPE enable line may not be directly wired to the GPE trigger line. In that case, when GPE enabling is frequently performed for edge-triggered GPEs, GPE status may stay set without being triggered. This patch may maginify this problem as it allows GPE enabling to be parallel performed during the process the GPEs are handled. This is an existing issue, because: 1. For task context: Current ACPI_GPE_DISPATCH_METHOD practices have proven that this isn't a real issue - we can re-enable edge-triggered GPE in a work queue where the GPE status bit might already be set. 2. For IRQ context: This can even happen when the GPE enabling occurs before returning from the GPE handler and after unlocking the GPE lock. Thus currently no code is included to protect this. Link: https://github.com/acpica/acpica/commit/199cad16 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>
2015-02-05 16:27:03 +08:00
if ((ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
ACPI_GPE_DISPATCH_HANDLER) ||
(ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
ACPI_GPE_DISPATCH_RAW_HANDLER)) {
/* Delete an installed handler block */
ACPI_FREE(gpe_event_info->dispatch.handler);
gpe_event_info->dispatch.handler = NULL;
gpe_event_info->flags &=
~ACPI_GPE_DISPATCH_MASK;
ACPICA: Events: Cleanup GPE dispatcher type obtaining code ACPICA commit 7926d5ca9452c87f866938dcea8f12e1efb58f89 There is an issue in acpi_install_gpe_handler() and acpi_remove_gpe_handler(). The code to obtain the GPE dispatcher type from the Handler->original_flags is wrong: if (((Handler->original_flags & ACPI_GPE_DISPATCH_METHOD) || (Handler->original_flags & ACPI_GPE_DISPATCH_NOTIFY)) && ACPI_GPE_DISPATCH_NOTIFY is 0x03 and ACPI_GPE_DISPATCH_METHOD is 0x02, thus this statement is TRUE for the following dispatcher types: 0x01 (ACPI_GPE_DISPATCH_HANDLER): not expected 0x02 (ACPI_GPE_DISPATCH_METHOD): expected 0x03 (ACPI_GPE_DISPATCH_NOTIFY): expected There is no functional issue due to this because Handler->original_flags is only set in acpi_install_gpe_handler(), and an earlier checker has excluded the ACPI_GPE_DISPATCH_HANDLER: if ((gpe_event_info->Flags & ACPI_GPE_DISPATCH_MASK) == ACPI_GPE_DISPATCH_HANDLER) { Status = AE_ALREADY_EXISTS; goto free_and_exit; } ... Handler->original_flags = (u8) (gpe_event_info->Flags & (ACPI_GPE_XRUPT_TYPE_MASK | ACPI_GPE_DISPATCH_MASK)); We need to clean this up before modifying the GPE dispatcher type values. In order to prevent such issue from happening in the future, this patch introduces ACPI_GPE_DISPATCH_TYPE() macro to be used to obtain the GPE dispatcher types. Lv Zheng. Link: https://github.com/acpica/acpica/commit/7926d5ca 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>
2015-02-05 15:20:29 +08:00
} else if (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags)
== ACPI_GPE_DISPATCH_NOTIFY) {
/* Delete the implicit notification device list */
notify = gpe_event_info->dispatch.notify_list;
while (notify) {
next = notify->next;
ACPI_FREE(notify);
notify = next;
}
gpe_event_info->dispatch.notify_list = NULL;
gpe_event_info->flags &=
~ACPI_GPE_DISPATCH_MASK;
}
}
}
return_ACPI_STATUS(AE_OK);
}
#endif /* !ACPI_REDUCED_HARDWARE */