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linux_dsm_epyc7002/drivers/acpi/ec.c
Rafael J. Wysocki 3df663a147 ACPI: EC: Reference count query handlers under lock 
There is a race condition in acpi_ec_get_query_handler()
theoretically allowing query handlers to go away before refernce
counting them.

In order to avoid it, call kref_get() on query handlers under
ec->mutex.

Also simplify the code a bit while at it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-12-27 11:04:21 +01:00

2194 lines
58 KiB
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ec.c - ACPI Embedded Controller Driver (v3)
*
* Copyright (C) 2001-2015 Intel Corporation
* Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
* 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
* 2006 Denis Sadykov <denis.m.sadykov@intel.com>
* 2004 Luming Yu <luming.yu@intel.com>
* 2001, 2002 Andy Grover <andrew.grover@intel.com>
* 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Copyright (C) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
*/
/* Uncomment next line to get verbose printout */
/* #define DEBUG */
#define pr_fmt(fmt) "ACPI: EC: " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <asm/io.h>
#include "internal.h"
#define ACPI_EC_CLASS "embedded_controller"
#define ACPI_EC_DEVICE_NAME "Embedded Controller"
#define ACPI_EC_FILE_INFO "info"
/* EC status register */
#define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */
#define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */
#define ACPI_EC_FLAG_CMD 0x08 /* Input buffer contains a command */
#define ACPI_EC_FLAG_BURST 0x10 /* burst mode */
#define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */
/*
* The SCI_EVT clearing timing is not defined by the ACPI specification.
* This leads to lots of practical timing issues for the host EC driver.
* The following variations are defined (from the target EC firmware's
* perspective):
* STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
* target can clear SCI_EVT at any time so long as the host can see
* the indication by reading the status register (EC_SC). So the
* host should re-check SCI_EVT after the first time the SCI_EVT
* indication is seen, which is the same time the query request
* (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
* at any later time could indicate another event. Normally such
* kind of EC firmware has implemented an event queue and will
* return 0x00 to indicate "no outstanding event".
* QUERY: After seeing the query request (QR_EC) written to the command
* register (EC_CMD) by the host and having prepared the responding
* event value in the data register (EC_DATA), the target can safely
* clear SCI_EVT because the target can confirm that the current
* event is being handled by the host. The host then should check
* SCI_EVT right after reading the event response from the data
* register (EC_DATA).
* EVENT: After seeing the event response read from the data register
* (EC_DATA) by the host, the target can clear SCI_EVT. As the
* target requires time to notice the change in the data register
* (EC_DATA), the host may be required to wait additional guarding
* time before checking the SCI_EVT again. Such guarding may not be
* necessary if the host is notified via another IRQ.
*/
#define ACPI_EC_EVT_TIMING_STATUS 0x00
#define ACPI_EC_EVT_TIMING_QUERY 0x01
#define ACPI_EC_EVT_TIMING_EVENT 0x02
/* EC commands */
enum ec_command {
ACPI_EC_COMMAND_READ = 0x80,
ACPI_EC_COMMAND_WRITE = 0x81,
ACPI_EC_BURST_ENABLE = 0x82,
ACPI_EC_BURST_DISABLE = 0x83,
ACPI_EC_COMMAND_QUERY = 0x84,
};
#define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
#define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
#define ACPI_EC_UDELAY_POLL 550 /* Wait 1ms for EC transaction polling */
#define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
* when trying to clear the EC */
#define ACPI_EC_MAX_QUERIES 16 /* Maximum number of parallel queries */
enum {
EC_FLAGS_QUERY_ENABLED, /* Query is enabled */
EC_FLAGS_QUERY_PENDING, /* Query is pending */
EC_FLAGS_QUERY_GUARDING, /* Guard for SCI_EVT check */
EC_FLAGS_EVENT_HANDLER_INSTALLED, /* Event handler installed */
EC_FLAGS_EC_HANDLER_INSTALLED, /* OpReg handler installed */
EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
EC_FLAGS_STARTED, /* Driver is started */
EC_FLAGS_STOPPED, /* Driver is stopped */
EC_FLAGS_EVENTS_MASKED, /* Events masked */
};
#define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
#define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
module_param(ec_delay, uint, 0644);
MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
module_param(ec_max_queries, uint, 0644);
MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
static bool ec_busy_polling __read_mostly;
module_param(ec_busy_polling, bool, 0644);
MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
module_param(ec_polling_guard, uint, 0644);
MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
/*
* If the number of false interrupts per one transaction exceeds
* this threshold, will think there is a GPE storm happened and
* will disable the GPE for normal transaction.
*/
static unsigned int ec_storm_threshold __read_mostly = 8;
module_param(ec_storm_threshold, uint, 0644);
MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
static bool ec_freeze_events __read_mostly = false;
module_param(ec_freeze_events, bool, 0644);
MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
static bool ec_no_wakeup __read_mostly;
module_param(ec_no_wakeup, bool, 0644);
MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
struct acpi_ec_query_handler {
struct list_head node;
acpi_ec_query_func func;
acpi_handle handle;
void *data;
u8 query_bit;
struct kref kref;
};
struct transaction {
const u8 *wdata;
u8 *rdata;
unsigned short irq_count;
u8 command;
u8 wi;
u8 ri;
u8 wlen;
u8 rlen;
u8 flags;
};
struct acpi_ec_query {
struct transaction transaction;
struct work_struct work;
struct acpi_ec_query_handler *handler;
};
static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
static void advance_transaction(struct acpi_ec *ec);
static void acpi_ec_event_handler(struct work_struct *work);
static void acpi_ec_event_processor(struct work_struct *work);
struct acpi_ec *first_ec;
EXPORT_SYMBOL(first_ec);
static struct acpi_ec *boot_ec;
static bool boot_ec_is_ecdt = false;
static struct workqueue_struct *ec_query_wq;
static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
/* --------------------------------------------------------------------------
* Logging/Debugging
* -------------------------------------------------------------------------- */
/*
* Splitters used by the developers to track the boundary of the EC
* handling processes.
*/
#ifdef DEBUG
#define EC_DBG_SEP " "
#define EC_DBG_DRV "+++++"
#define EC_DBG_STM "====="
#define EC_DBG_REQ "*****"
#define EC_DBG_EVT "#####"
#else
#define EC_DBG_SEP ""
#define EC_DBG_DRV
#define EC_DBG_STM
#define EC_DBG_REQ
#define EC_DBG_EVT
#endif
#define ec_log_raw(fmt, ...) \
pr_info(fmt "\n", ##__VA_ARGS__)
#define ec_dbg_raw(fmt, ...) \
pr_debug(fmt "\n", ##__VA_ARGS__)
#define ec_log(filter, fmt, ...) \
ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
#define ec_dbg(filter, fmt, ...) \
ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
#define ec_log_drv(fmt, ...) \
ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
#define ec_dbg_drv(fmt, ...) \
ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
#define ec_dbg_stm(fmt, ...) \
ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
#define ec_dbg_req(fmt, ...) \
ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
#define ec_dbg_evt(fmt, ...) \
ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
#define ec_dbg_ref(ec, fmt, ...) \
ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
/* --------------------------------------------------------------------------
* Device Flags
* -------------------------------------------------------------------------- */
static bool acpi_ec_started(struct acpi_ec *ec)
{
return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
!test_bit(EC_FLAGS_STOPPED, &ec->flags);
}
static bool acpi_ec_event_enabled(struct acpi_ec *ec)
{
/*
* There is an OSPM early stage logic. During the early stages
* (boot/resume), OSPMs shouldn't enable the event handling, only
* the EC transactions are allowed to be performed.
*/
if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
return false;
/*
* However, disabling the event handling is experimental for late
* stage (suspend), and is controlled by the boot parameter of
* "ec_freeze_events":
* 1. true: The EC event handling is disabled before entering
* the noirq stage.
* 2. false: The EC event handling is automatically disabled as
* soon as the EC driver is stopped.
*/
if (ec_freeze_events)
return acpi_ec_started(ec);
else
return test_bit(EC_FLAGS_STARTED, &ec->flags);
}
static bool acpi_ec_flushed(struct acpi_ec *ec)
{
return ec->reference_count == 1;
}
/* --------------------------------------------------------------------------
* EC Registers
* -------------------------------------------------------------------------- */
static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
{
u8 x = inb(ec->command_addr);
ec_dbg_raw("EC_SC(R) = 0x%2.2x "
"SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
x,
!!(x & ACPI_EC_FLAG_SCI),
!!(x & ACPI_EC_FLAG_BURST),
!!(x & ACPI_EC_FLAG_CMD),
!!(x & ACPI_EC_FLAG_IBF),
!!(x & ACPI_EC_FLAG_OBF));
return x;
}
static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
{
u8 x = inb(ec->data_addr);
ec->timestamp = jiffies;
ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
return x;
}
static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
{
ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
outb(command, ec->command_addr);
ec->timestamp = jiffies;
}
static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
{
ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
outb(data, ec->data_addr);
ec->timestamp = jiffies;
}
#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
static const char *acpi_ec_cmd_string(u8 cmd)
{
switch (cmd) {
case 0x80:
return "RD_EC";
case 0x81:
return "WR_EC";
case 0x82:
return "BE_EC";
case 0x83:
return "BD_EC";
case 0x84:
return "QR_EC";
}
return "UNKNOWN";
}
#else
#define acpi_ec_cmd_string(cmd) "UNDEF"
#endif
/* --------------------------------------------------------------------------
* GPE Registers
* -------------------------------------------------------------------------- */
static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
{
acpi_event_status gpe_status = 0;
(void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
}
static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
{
if (open)
acpi_enable_gpe(NULL, ec->gpe);
else {
BUG_ON(ec->reference_count < 1);
acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
}
if (acpi_ec_is_gpe_raised(ec)) {
/*
* On some platforms, EN=1 writes cannot trigger GPE. So
* software need to manually trigger a pseudo GPE event on
* EN=1 writes.
*/
ec_dbg_raw("Polling quirk");
advance_transaction(ec);
}
}
static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
{
if (close)
acpi_disable_gpe(NULL, ec->gpe);
else {
BUG_ON(ec->reference_count < 1);
acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
}
}
static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
{
/*
* GPE STS is a W1C register, which means:
* 1. Software can clear it without worrying about clearing other
* GPEs' STS bits when the hardware sets them in parallel.
* 2. As long as software can ensure only clearing it when it is
* set, hardware won't set it in parallel.
* So software can clear GPE in any contexts.
* Warning: do not move the check into advance_transaction() as the
* EC commands will be sent without GPE raised.
*/
if (!acpi_ec_is_gpe_raised(ec))
return;
acpi_clear_gpe(NULL, ec->gpe);
}
/* --------------------------------------------------------------------------
* Transaction Management
* -------------------------------------------------------------------------- */
static void acpi_ec_submit_request(struct acpi_ec *ec)
{
ec->reference_count++;
if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
ec->gpe >= 0 && ec->reference_count == 1)
acpi_ec_enable_gpe(ec, true);
}
static void acpi_ec_complete_request(struct acpi_ec *ec)
{
bool flushed = false;
ec->reference_count--;
if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
ec->gpe >= 0 && ec->reference_count == 0)
acpi_ec_disable_gpe(ec, true);
flushed = acpi_ec_flushed(ec);
if (flushed)
wake_up(&ec->wait);
}
static void acpi_ec_mask_events(struct acpi_ec *ec)
{
if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
if (ec->gpe >= 0)
acpi_ec_disable_gpe(ec, false);
else
disable_irq_nosync(ec->irq);
ec_dbg_drv("Polling enabled");
set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
}
}
static void acpi_ec_unmask_events(struct acpi_ec *ec)
{
if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
if (ec->gpe >= 0)
acpi_ec_enable_gpe(ec, false);
else
enable_irq(ec->irq);
ec_dbg_drv("Polling disabled");
}
}
/*
* acpi_ec_submit_flushable_request() - Increase the reference count unless
* the flush operation is not in
* progress
* @ec: the EC device
*
* This function must be used before taking a new action that should hold
* the reference count. If this function returns false, then the action
* must be discarded or it will prevent the flush operation from being
* completed.
*/
static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
{
if (!acpi_ec_started(ec))
return false;
acpi_ec_submit_request(ec);
return true;
}
static void acpi_ec_submit_query(struct acpi_ec *ec)
{
acpi_ec_mask_events(ec);
if (!acpi_ec_event_enabled(ec))
return;
if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
ec_dbg_evt("Command(%s) submitted/blocked",
acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
ec->nr_pending_queries++;
schedule_work(&ec->work);
}
}
static void acpi_ec_complete_query(struct acpi_ec *ec)
{
if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
ec_dbg_evt("Command(%s) unblocked",
acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
acpi_ec_unmask_events(ec);
}
static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
{
if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
ec_log_drv("event unblocked");
/*
* Unconditionally invoke this once after enabling the event
* handling mechanism to detect the pending events.
*/
advance_transaction(ec);
}
static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
{
if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
ec_log_drv("event blocked");
}
/*
* Process _Q events that might have accumulated in the EC.
* Run with locked ec mutex.
*/
static void acpi_ec_clear(struct acpi_ec *ec)
{
int i, status;
u8 value = 0;
for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
status = acpi_ec_query(ec, &value);
if (status || !value)
break;
}
if (unlikely(i == ACPI_EC_CLEAR_MAX))
pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
else
pr_info("%d stale EC events cleared\n", i);
}
static void acpi_ec_enable_event(struct acpi_ec *ec)
{
unsigned long flags;
spin_lock_irqsave(&ec->lock, flags);
if (acpi_ec_started(ec))
__acpi_ec_enable_event(ec);
spin_unlock_irqrestore(&ec->lock, flags);
/* Drain additional events if hardware requires that */
if (EC_FLAGS_CLEAR_ON_RESUME)
acpi_ec_clear(ec);
}
#ifdef CONFIG_PM_SLEEP
static void __acpi_ec_flush_work(void)
{
flush_scheduled_work(); /* flush ec->work */
flush_workqueue(ec_query_wq); /* flush queries */
}
static void acpi_ec_disable_event(struct acpi_ec *ec)
{
unsigned long flags;
spin_lock_irqsave(&ec->lock, flags);
__acpi_ec_disable_event(ec);
spin_unlock_irqrestore(&ec->lock, flags);
/*
* When ec_freeze_events is true, we need to flush events in
* the proper position before entering the noirq stage.
*/
__acpi_ec_flush_work();
}
void acpi_ec_flush_work(void)
{
/* Without ec_query_wq there is nothing to flush. */
if (!ec_query_wq)
return;
__acpi_ec_flush_work();
}
#endif /* CONFIG_PM_SLEEP */
static bool acpi_ec_guard_event(struct acpi_ec *ec)
{
bool guarded = true;
unsigned long flags;
spin_lock_irqsave(&ec->lock, flags);
/*
* If firmware SCI_EVT clearing timing is "event", we actually
* don't know when the SCI_EVT will be cleared by firmware after
* evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
* acceptable period.
*
* The guarding period begins when EC_FLAGS_QUERY_PENDING is
* flagged, which means SCI_EVT check has just been performed.
* But if the current transaction is ACPI_EC_COMMAND_QUERY, the
* guarding should have already been performed (via
* EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
* ACPI_EC_COMMAND_QUERY transaction can be transitioned into
* ACPI_EC_COMMAND_POLL state immediately.
*/
if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
!test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
(ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
guarded = false;
spin_unlock_irqrestore(&ec->lock, flags);
return guarded;
}
static int ec_transaction_polled(struct acpi_ec *ec)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&ec->lock, flags);
if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
ret = 1;
spin_unlock_irqrestore(&ec->lock, flags);
return ret;
}
static int ec_transaction_completed(struct acpi_ec *ec)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&ec->lock, flags);
if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
ret = 1;
spin_unlock_irqrestore(&ec->lock, flags);
return ret;
}
static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
{
ec->curr->flags |= flag;
if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
flag == ACPI_EC_COMMAND_POLL)
acpi_ec_complete_query(ec);
if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
flag == ACPI_EC_COMMAND_COMPLETE)
acpi_ec_complete_query(ec);
if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
flag == ACPI_EC_COMMAND_COMPLETE)
set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
}
}
static void advance_transaction(struct acpi_ec *ec)
{
struct transaction *t;
u8 status;
bool wakeup = false;
ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
smp_processor_id());
/*
* By always clearing STS before handling all indications, we can
* ensure a hardware STS 0->1 change after this clearing can always
* trigger a GPE interrupt.
*/
if (ec->gpe >= 0)
acpi_ec_clear_gpe(ec);
status = acpi_ec_read_status(ec);
t = ec->curr;
/*
* Another IRQ or a guarded polling mode advancement is detected,
* the next QR_EC submission is then allowed.
*/
if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
(!ec->nr_pending_queries ||
test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
acpi_ec_complete_query(ec);
}
}
if (!t)
goto err;
if (t->flags & ACPI_EC_COMMAND_POLL) {
if (t->wlen > t->wi) {
if ((status & ACPI_EC_FLAG_IBF) == 0)
acpi_ec_write_data(ec, t->wdata[t->wi++]);
else
goto err;
} else if (t->rlen > t->ri) {
if ((status & ACPI_EC_FLAG_OBF) == 1) {
t->rdata[t->ri++] = acpi_ec_read_data(ec);
if (t->rlen == t->ri) {
ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
if (t->command == ACPI_EC_COMMAND_QUERY)
ec_dbg_evt("Command(%s) completed by hardware",
acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
wakeup = true;
}
} else
goto err;
} else if (t->wlen == t->wi &&
(status & ACPI_EC_FLAG_IBF) == 0) {
ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
wakeup = true;
}
goto out;
} else {
if (EC_FLAGS_QUERY_HANDSHAKE &&
!(status & ACPI_EC_FLAG_SCI) &&
(t->command == ACPI_EC_COMMAND_QUERY)) {
ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
t->rdata[t->ri++] = 0x00;
ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
ec_dbg_evt("Command(%s) completed by software",
acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
wakeup = true;
} else if ((status & ACPI_EC_FLAG_IBF) == 0) {
acpi_ec_write_cmd(ec, t->command);
ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
} else
goto err;
goto out;
}
err:
/*
* If SCI bit is set, then don't think it's a false IRQ
* otherwise will take a not handled IRQ as a false one.
*/
if (!(status & ACPI_EC_FLAG_SCI)) {
if (in_interrupt() && t) {
if (t->irq_count < ec_storm_threshold)
++t->irq_count;
/* Allow triggering on 0 threshold */
if (t->irq_count == ec_storm_threshold)
acpi_ec_mask_events(ec);
}
}
out:
if (status & ACPI_EC_FLAG_SCI)
acpi_ec_submit_query(ec);
if (wakeup && in_interrupt())
wake_up(&ec->wait);
}
static void start_transaction(struct acpi_ec *ec)
{
ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
ec->curr->flags = 0;
}
static int ec_guard(struct acpi_ec *ec)
{
unsigned long guard = usecs_to_jiffies(ec->polling_guard);
unsigned long timeout = ec->timestamp + guard;
/* Ensure guarding period before polling EC status */
do {
if (ec->busy_polling) {
/* Perform busy polling */
if (ec_transaction_completed(ec))
return 0;
udelay(jiffies_to_usecs(guard));
} else {
/*
* Perform wait polling
* 1. Wait the transaction to be completed by the
* GPE handler after the transaction enters
* ACPI_EC_COMMAND_POLL state.
* 2. A special guarding logic is also required
* for event clearing mode "event" before the
* transaction enters ACPI_EC_COMMAND_POLL
* state.
*/
if (!ec_transaction_polled(ec) &&
!acpi_ec_guard_event(ec))
break;
if (wait_event_timeout(ec->wait,
ec_transaction_completed(ec),
guard))
return 0;
}
} while (time_before(jiffies, timeout));
return -ETIME;
}
static int ec_poll(struct acpi_ec *ec)
{
unsigned long flags;
int repeat = 5; /* number of command restarts */
while (repeat--) {
unsigned long delay = jiffies +
msecs_to_jiffies(ec_delay);
do {
if (!ec_guard(ec))
return 0;
spin_lock_irqsave(&ec->lock, flags);
advance_transaction(ec);
spin_unlock_irqrestore(&ec->lock, flags);
} while (time_before(jiffies, delay));
pr_debug("controller reset, restart transaction\n");
spin_lock_irqsave(&ec->lock, flags);
start_transaction(ec);
spin_unlock_irqrestore(&ec->lock, flags);
}
return -ETIME;
}
static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
struct transaction *t)
{
unsigned long tmp;
int ret = 0;
/* start transaction */
spin_lock_irqsave(&ec->lock, tmp);
/* Enable GPE for command processing (IBF=0/OBF=1) */
if (!acpi_ec_submit_flushable_request(ec)) {
ret = -EINVAL;
goto unlock;
}
ec_dbg_ref(ec, "Increase command");
/* following two actions should be kept atomic */
ec->curr = t;
ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
start_transaction(ec);
spin_unlock_irqrestore(&ec->lock, tmp);
ret = ec_poll(ec);
spin_lock_irqsave(&ec->lock, tmp);
if (t->irq_count == ec_storm_threshold)
acpi_ec_unmask_events(ec);
ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
ec->curr = NULL;
/* Disable GPE for command processing (IBF=0/OBF=1) */
acpi_ec_complete_request(ec);
ec_dbg_ref(ec, "Decrease command");
unlock:
spin_unlock_irqrestore(&ec->lock, tmp);
return ret;
}
static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
{
int status;
u32 glk;
if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
return -EINVAL;
if (t->rdata)
memset(t->rdata, 0, t->rlen);
mutex_lock(&ec->mutex);
if (ec->global_lock) {
status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
if (ACPI_FAILURE(status)) {
status = -ENODEV;
goto unlock;
}
}
status = acpi_ec_transaction_unlocked(ec, t);
if (ec->global_lock)
acpi_release_global_lock(glk);
unlock:
mutex_unlock(&ec->mutex);
return status;
}
static int acpi_ec_burst_enable(struct acpi_ec *ec)
{
u8 d;
struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
.wdata = NULL, .rdata = &d,
.wlen = 0, .rlen = 1};
return acpi_ec_transaction(ec, &t);
}
static int acpi_ec_burst_disable(struct acpi_ec *ec)
{
struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
.wdata = NULL, .rdata = NULL,
.wlen = 0, .rlen = 0};
return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
acpi_ec_transaction(ec, &t) : 0;
}
static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
{
int result;
u8 d;
struct transaction t = {.command = ACPI_EC_COMMAND_READ,
.wdata = &address, .rdata = &d,
.wlen = 1, .rlen = 1};
result = acpi_ec_transaction(ec, &t);
*data = d;
return result;
}
static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
{
u8 wdata[2] = { address, data };
struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
.wdata = wdata, .rdata = NULL,
.wlen = 2, .rlen = 0};
return acpi_ec_transaction(ec, &t);
}
int ec_read(u8 addr, u8 *val)
{
int err;
u8 temp_data;
if (!first_ec)
return -ENODEV;
err = acpi_ec_read(first_ec, addr, &temp_data);
if (!err) {
*val = temp_data;
return 0;
}
return err;
}
EXPORT_SYMBOL(ec_read);
int ec_write(u8 addr, u8 val)
{
int err;
if (!first_ec)
return -ENODEV;
err = acpi_ec_write(first_ec, addr, val);
return err;
}
EXPORT_SYMBOL(ec_write);
int ec_transaction(u8 command,
const u8 *wdata, unsigned wdata_len,
u8 *rdata, unsigned rdata_len)
{
struct transaction t = {.command = command,
.wdata = wdata, .rdata = rdata,
.wlen = wdata_len, .rlen = rdata_len};
if (!first_ec)
return -ENODEV;
return acpi_ec_transaction(first_ec, &t);
}
EXPORT_SYMBOL(ec_transaction);
/* Get the handle to the EC device */
acpi_handle ec_get_handle(void)
{
if (!first_ec)
return NULL;
return first_ec->handle;
}
EXPORT_SYMBOL(ec_get_handle);
static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
{
unsigned long flags;
spin_lock_irqsave(&ec->lock, flags);
if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
ec_dbg_drv("Starting EC");
/* Enable GPE for event processing (SCI_EVT=1) */
if (!resuming) {
acpi_ec_submit_request(ec);
ec_dbg_ref(ec, "Increase driver");
}
ec_log_drv("EC started");
}
spin_unlock_irqrestore(&ec->lock, flags);
}
static bool acpi_ec_stopped(struct acpi_ec *ec)
{
unsigned long flags;
bool flushed;
spin_lock_irqsave(&ec->lock, flags);
flushed = acpi_ec_flushed(ec);
spin_unlock_irqrestore(&ec->lock, flags);
return flushed;
}
static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
{
unsigned long flags;
spin_lock_irqsave(&ec->lock, flags);
if (acpi_ec_started(ec)) {
ec_dbg_drv("Stopping EC");
set_bit(EC_FLAGS_STOPPED, &ec->flags);
spin_unlock_irqrestore(&ec->lock, flags);
wait_event(ec->wait, acpi_ec_stopped(ec));
spin_lock_irqsave(&ec->lock, flags);
/* Disable GPE for event processing (SCI_EVT=1) */
if (!suspending) {
acpi_ec_complete_request(ec);
ec_dbg_ref(ec, "Decrease driver");
} else if (!ec_freeze_events)
__acpi_ec_disable_event(ec);
clear_bit(EC_FLAGS_STARTED, &ec->flags);
clear_bit(EC_FLAGS_STOPPED, &ec->flags);
ec_log_drv("EC stopped");
}
spin_unlock_irqrestore(&ec->lock, flags);
}
static void acpi_ec_enter_noirq(struct acpi_ec *ec)
{
unsigned long flags;
spin_lock_irqsave(&ec->lock, flags);
ec->busy_polling = true;
ec->polling_guard = 0;
ec_log_drv("interrupt blocked");
spin_unlock_irqrestore(&ec->lock, flags);
}
static void acpi_ec_leave_noirq(struct acpi_ec *ec)
{
unsigned long flags;
spin_lock_irqsave(&ec->lock, flags);
ec->busy_polling = ec_busy_polling;
ec->polling_guard = ec_polling_guard;
ec_log_drv("interrupt unblocked");
spin_unlock_irqrestore(&ec->lock, flags);
}
void acpi_ec_block_transactions(void)
{
struct acpi_ec *ec = first_ec;
if (!ec)
return;
mutex_lock(&ec->mutex);
/* Prevent transactions from being carried out */
acpi_ec_stop(ec, true);
mutex_unlock(&ec->mutex);
}
void acpi_ec_unblock_transactions(void)
{
/*
* Allow transactions to happen again (this function is called from
* atomic context during wakeup, so we don't need to acquire the mutex).
*/
if (first_ec)
acpi_ec_start(first_ec, true);
}
/* --------------------------------------------------------------------------
Event Management
-------------------------------------------------------------------------- */
static struct acpi_ec_query_handler *
acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
{
struct acpi_ec_query_handler *handler;
mutex_lock(&ec->mutex);
list_for_each_entry(handler, &ec->list, node) {
if (value == handler->query_bit) {
kref_get(&handler->kref);
mutex_unlock(&ec->mutex);
return handler;
}
}
mutex_unlock(&ec->mutex);
return NULL;
}
static void acpi_ec_query_handler_release(struct kref *kref)
{
struct acpi_ec_query_handler *handler =
container_of(kref, struct acpi_ec_query_handler, kref);
kfree(handler);
}
static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
{
kref_put(&handler->kref, acpi_ec_query_handler_release);
}
int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
acpi_handle handle, acpi_ec_query_func func,
void *data)
{
struct acpi_ec_query_handler *handler =
kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
if (!handler)
return -ENOMEM;
handler->query_bit = query_bit;
handler->handle = handle;
handler->func = func;
handler->data = data;
mutex_lock(&ec->mutex);
kref_init(&handler->kref);
list_add(&handler->node, &ec->list);
mutex_unlock(&ec->mutex);
return 0;
}
EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
bool remove_all, u8 query_bit)
{
struct acpi_ec_query_handler *handler, *tmp;
LIST_HEAD(free_list);
mutex_lock(&ec->mutex);
list_for_each_entry_safe(handler, tmp, &ec->list, node) {
if (remove_all || query_bit == handler->query_bit) {
list_del_init(&handler->node);
list_add(&handler->node, &free_list);
}
}
mutex_unlock(&ec->mutex);
list_for_each_entry_safe(handler, tmp, &free_list, node)
acpi_ec_put_query_handler(handler);
}
void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
{
acpi_ec_remove_query_handlers(ec, false, query_bit);
}
EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
{
struct acpi_ec_query *q;
struct transaction *t;
q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
if (!q)
return NULL;
INIT_WORK(&q->work, acpi_ec_event_processor);
t = &q->transaction;
t->command = ACPI_EC_COMMAND_QUERY;
t->rdata = pval;
t->rlen = 1;
return q;
}
static void acpi_ec_delete_query(struct acpi_ec_query *q)
{
if (q) {
if (q->handler)
acpi_ec_put_query_handler(q->handler);
kfree(q);
}
}
static void acpi_ec_event_processor(struct work_struct *work)
{
struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
struct acpi_ec_query_handler *handler = q->handler;
ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
if (handler->func)
handler->func(handler->data);
else if (handler->handle)
acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
acpi_ec_delete_query(q);
}
static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
{
u8 value = 0;
int result;
struct acpi_ec_query *q;
q = acpi_ec_create_query(&value);
if (!q)
return -ENOMEM;
/*
* Query the EC to find out which _Qxx method we need to evaluate.
* Note that successful completion of the query causes the ACPI_EC_SCI
* bit to be cleared (and thus clearing the interrupt source).
*/
result = acpi_ec_transaction(ec, &q->transaction);
if (!value)
result = -ENODATA;
if (result)
goto err_exit;
q->handler = acpi_ec_get_query_handler_by_value(ec, value);
if (!q->handler) {
result = -ENODATA;
goto err_exit;
}
/*
* It is reported that _Qxx are evaluated in a parallel way on
* Windows:
* https://bugzilla.kernel.org/show_bug.cgi?id=94411
*
* Put this log entry before schedule_work() in order to make
* it appearing before any other log entries occurred during the
* work queue execution.
*/
ec_dbg_evt("Query(0x%02x) scheduled", value);
if (!queue_work(ec_query_wq, &q->work)) {
ec_dbg_evt("Query(0x%02x) overlapped", value);
result = -EBUSY;
}
err_exit:
if (result)
acpi_ec_delete_query(q);
if (data)
*data = value;
return result;
}
static void acpi_ec_check_event(struct acpi_ec *ec)
{
unsigned long flags;
if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
if (ec_guard(ec)) {
spin_lock_irqsave(&ec->lock, flags);
/*
* Take care of the SCI_EVT unless no one else is
* taking care of it.
*/
if (!ec->curr)
advance_transaction(ec);
spin_unlock_irqrestore(&ec->lock, flags);
}
}
}
static void acpi_ec_event_handler(struct work_struct *work)
{
unsigned long flags;
struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
ec_dbg_evt("Event started");
spin_lock_irqsave(&ec->lock, flags);
while (ec->nr_pending_queries) {
spin_unlock_irqrestore(&ec->lock, flags);
(void)acpi_ec_query(ec, NULL);
spin_lock_irqsave(&ec->lock, flags);
ec->nr_pending_queries--;
/*
* Before exit, make sure that this work item can be
* scheduled again. There might be QR_EC failures, leaving
* EC_FLAGS_QUERY_PENDING uncleared and preventing this work
* item from being scheduled again.
*/
if (!ec->nr_pending_queries) {
if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
acpi_ec_complete_query(ec);
}
}
spin_unlock_irqrestore(&ec->lock, flags);
ec_dbg_evt("Event stopped");
acpi_ec_check_event(ec);
}
static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
{
unsigned long flags;
spin_lock_irqsave(&ec->lock, flags);
advance_transaction(ec);
spin_unlock_irqrestore(&ec->lock, flags);
}
static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
u32 gpe_number, void *data)
{
acpi_ec_handle_interrupt(data);
return ACPI_INTERRUPT_HANDLED;
}
static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
{
acpi_ec_handle_interrupt(data);
return IRQ_HANDLED;
}
/* --------------------------------------------------------------------------
* Address Space Management
* -------------------------------------------------------------------------- */
static acpi_status
acpi_ec_space_handler(u32 function, acpi_physical_address address,
u32 bits, u64 *value64,
void *handler_context, void *region_context)
{
struct acpi_ec *ec = handler_context;
int result = 0, i, bytes = bits / 8;
u8 *value = (u8 *)value64;
if ((address > 0xFF) || !value || !handler_context)
return AE_BAD_PARAMETER;
if (function != ACPI_READ && function != ACPI_WRITE)
return AE_BAD_PARAMETER;
if (ec->busy_polling || bits > 8)
acpi_ec_burst_enable(ec);
for (i = 0; i < bytes; ++i, ++address, ++value)
result = (function == ACPI_READ) ?
acpi_ec_read(ec, address, value) :
acpi_ec_write(ec, address, *value);
if (ec->busy_polling || bits > 8)
acpi_ec_burst_disable(ec);
switch (result) {
case -EINVAL:
return AE_BAD_PARAMETER;
case -ENODEV:
return AE_NOT_FOUND;
case -ETIME:
return AE_TIME;
default:
return AE_OK;
}
}
/* --------------------------------------------------------------------------
* Driver Interface
* -------------------------------------------------------------------------- */
static acpi_status
ec_parse_io_ports(struct acpi_resource *resource, void *context);
static void acpi_ec_free(struct acpi_ec *ec)
{
if (first_ec == ec)
first_ec = NULL;
if (boot_ec == ec)
boot_ec = NULL;
kfree(ec);
}
static struct acpi_ec *acpi_ec_alloc(void)
{
struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
if (!ec)
return NULL;
mutex_init(&ec->mutex);
init_waitqueue_head(&ec->wait);
INIT_LIST_HEAD(&ec->list);
spin_lock_init(&ec->lock);
INIT_WORK(&ec->work, acpi_ec_event_handler);
ec->timestamp = jiffies;
ec->busy_polling = true;
ec->polling_guard = 0;
ec->gpe = -1;
ec->irq = -1;
return ec;
}
static acpi_status
acpi_ec_register_query_methods(acpi_handle handle, u32 level,
void *context, void **return_value)
{
char node_name[5];
struct acpi_buffer buffer = { sizeof(node_name), node_name };
struct acpi_ec *ec = context;
int value = 0;
acpi_status status;
status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
return AE_OK;
}
static acpi_status
ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
{
acpi_status status;
unsigned long long tmp = 0;
struct acpi_ec *ec = context;
/* clear addr values, ec_parse_io_ports depend on it */
ec->command_addr = ec->data_addr = 0;
status = acpi_walk_resources(handle, METHOD_NAME__CRS,
ec_parse_io_ports, ec);
if (ACPI_FAILURE(status))
return status;
if (ec->data_addr == 0 || ec->command_addr == 0)
return AE_OK;
if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
/*
* Always inherit the GPE number setting from the ECDT
* EC.
*/
ec->gpe = boot_ec->gpe;
} else {
/* Get GPE bit assignment (EC events). */
/* TODO: Add support for _GPE returning a package */
status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
if (ACPI_SUCCESS(status))
ec->gpe = tmp;
/*
* Errors are non-fatal, allowing for ACPI Reduced Hardware
* platforms which use GpioInt instead of GPE.
*/
}
/* Use the global lock for all EC transactions? */
tmp = 0;
acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
ec->global_lock = tmp;
ec->handle = handle;
return AE_CTRL_TERMINATE;
}
static void install_gpe_event_handler(struct acpi_ec *ec)
{
acpi_status status =
acpi_install_gpe_raw_handler(NULL, ec->gpe,
ACPI_GPE_EDGE_TRIGGERED,
&acpi_ec_gpe_handler,
ec);
if (ACPI_SUCCESS(status)) {
/* This is not fatal as we can poll EC events */
set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
acpi_ec_leave_noirq(ec);
if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
ec->reference_count >= 1)
acpi_ec_enable_gpe(ec, true);
}
}
/* ACPI reduced hardware platforms use a GpioInt specified in _CRS. */
static int install_gpio_irq_event_handler(struct acpi_ec *ec,
struct acpi_device *device)
{
int irq = acpi_dev_gpio_irq_get(device, 0);
int ret;
if (irq < 0)
return irq;
ret = request_irq(irq, acpi_ec_irq_handler, IRQF_SHARED,
"ACPI EC", ec);
/*
* Unlike the GPE case, we treat errors here as fatal, we'll only
* implement GPIO polling if we find a case that needs it.
*/
if (ret < 0)
return ret;
ec->irq = irq;
set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
acpi_ec_leave_noirq(ec);
return 0;
}
/*
* Note: This function returns an error code only when the address space
* handler is not installed, which means "not able to handle
* transactions".
*/
static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,
bool handle_events)
{
acpi_status status;
acpi_ec_start(ec, false);
if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
acpi_ec_enter_noirq(ec);
status = acpi_install_address_space_handler(ec->handle,
ACPI_ADR_SPACE_EC,
&acpi_ec_space_handler,
NULL, ec);
if (ACPI_FAILURE(status)) {
if (status == AE_NOT_FOUND) {
/*
* Maybe OS fails in evaluating the _REG
* object. The AE_NOT_FOUND error will be
* ignored and OS * continue to initialize
* EC.
*/
pr_err("Fail in evaluating the _REG object"
" of EC device. Broken bios is suspected.\n");
} else {
acpi_ec_stop(ec, false);
return -ENODEV;
}
}
set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
}
if (!handle_events)
return 0;
if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
/* Find and register all query methods */
acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
acpi_ec_register_query_methods,
NULL, ec, NULL);
set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
}
if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
if (ec->gpe >= 0) {
install_gpe_event_handler(ec);
} else if (device) {
int ret = install_gpio_irq_event_handler(ec, device);
if (ret)
return ret;
} else { /* No GPE and no GpioInt? */
return -ENODEV;
}
}
/* EC is fully operational, allow queries */
acpi_ec_enable_event(ec);
return 0;
}
static void ec_remove_handlers(struct acpi_ec *ec)
{
if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
pr_err("failed to remove space handler\n");
clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
}
/*
* Stops handling the EC transactions after removing the operation
* region handler. This is required because _REG(DISCONNECT)
* invoked during the removal can result in new EC transactions.
*
* Flushes the EC requests and thus disables the GPE before
* removing the GPE handler. This is required by the current ACPICA
* GPE core. ACPICA GPE core will automatically disable a GPE when
* it is indicated but there is no way to handle it. So the drivers
* must disable the GPEs prior to removing the GPE handlers.
*/
acpi_ec_stop(ec, false);
if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
if (ec->gpe >= 0 &&
ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
&acpi_ec_gpe_handler)))
pr_err("failed to remove gpe handler\n");
if (ec->irq >= 0)
free_irq(ec->irq, ec);
clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
}
if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
acpi_ec_remove_query_handlers(ec, true, 0);
clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
}
}
static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device,
bool handle_events)
{
int ret;
ret = ec_install_handlers(ec, device, handle_events);
if (ret)
return ret;
/* First EC capable of handling transactions */
if (!first_ec) {
first_ec = ec;
acpi_handle_info(first_ec->handle, "Used as first EC\n");
}
acpi_handle_info(ec->handle,
"GPE=0x%x, IRQ=%d, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
ec->gpe, ec->irq, ec->command_addr, ec->data_addr);
return ret;
}
static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
{
struct acpi_table_ecdt *ecdt_ptr;
acpi_status status;
acpi_handle handle;
status = acpi_get_table(ACPI_SIG_ECDT, 1,
(struct acpi_table_header **)&ecdt_ptr);
if (ACPI_FAILURE(status))
return false;
status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
if (ACPI_FAILURE(status))
return false;
*phandle = handle;
return true;
}
static int acpi_ec_add(struct acpi_device *device)
{
struct acpi_ec *ec = NULL;
bool dep_update = true;
acpi_status status;
int ret;
strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_EC_CLASS);
if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
boot_ec_is_ecdt = true;
ec = boot_ec;
dep_update = false;
} else {
ec = acpi_ec_alloc();
if (!ec)
return -ENOMEM;
status = ec_parse_device(device->handle, 0, ec, NULL);
if (status != AE_CTRL_TERMINATE) {
ret = -EINVAL;
goto err_alloc;
}
if (boot_ec && ec->command_addr == boot_ec->command_addr &&
ec->data_addr == boot_ec->data_addr) {
boot_ec_is_ecdt = false;
/*
* Trust PNP0C09 namespace location rather than
* ECDT ID. But trust ECDT GPE rather than _GPE
* because of ASUS quirks, so do not change
* boot_ec->gpe to ec->gpe.
*/
boot_ec->handle = ec->handle;
acpi_handle_debug(ec->handle, "duplicated.\n");
acpi_ec_free(ec);
ec = boot_ec;
}
}
ret = acpi_ec_setup(ec, device, true);
if (ret)
goto err_query;
if (ec == boot_ec)
acpi_handle_info(boot_ec->handle,
"Boot %s EC used to handle transactions and events\n",
boot_ec_is_ecdt ? "ECDT" : "DSDT");
device->driver_data = ec;
ret = !!request_region(ec->data_addr, 1, "EC data");
WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
ret = !!request_region(ec->command_addr, 1, "EC cmd");
WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
if (dep_update) {
/* Reprobe devices depending on the EC */
acpi_walk_dep_device_list(ec->handle);
}
acpi_handle_debug(ec->handle, "enumerated.\n");
return 0;
err_query:
if (ec != boot_ec)
acpi_ec_remove_query_handlers(ec, true, 0);
err_alloc:
if (ec != boot_ec)
acpi_ec_free(ec);
return ret;
}
static int acpi_ec_remove(struct acpi_device *device)
{
struct acpi_ec *ec;
if (!device)
return -EINVAL;
ec = acpi_driver_data(device);
release_region(ec->data_addr, 1);
release_region(ec->command_addr, 1);
device->driver_data = NULL;
if (ec != boot_ec) {
ec_remove_handlers(ec);
acpi_ec_free(ec);
}
return 0;
}
static acpi_status
ec_parse_io_ports(struct acpi_resource *resource, void *context)
{
struct acpi_ec *ec = context;
if (resource->type != ACPI_RESOURCE_TYPE_IO)
return AE_OK;
/*
* The first address region returned is the data port, and
* the second address region returned is the status/command
* port.
*/
if (ec->data_addr == 0)
ec->data_addr = resource->data.io.minimum;
else if (ec->command_addr == 0)
ec->command_addr = resource->data.io.minimum;
else
return AE_CTRL_TERMINATE;
return AE_OK;
}
static const struct acpi_device_id ec_device_ids[] = {
{"PNP0C09", 0},
{ACPI_ECDT_HID, 0},
{"", 0},
};
/*
* This function is not Windows-compatible as Windows never enumerates the
* namespace EC before the main ACPI device enumeration process. It is
* retained for historical reason and will be deprecated in the future.
*/
void __init acpi_ec_dsdt_probe(void)
{
struct acpi_ec *ec;
acpi_status status;
int ret;
/*
* If a platform has ECDT, there is no need to proceed as the
* following probe is not a part of the ACPI device enumeration,
* executing _STA is not safe, and thus this probe may risk of
* picking up an invalid EC device.
*/
if (boot_ec)
return;
ec = acpi_ec_alloc();
if (!ec)
return;
/*
* At this point, the namespace is initialized, so start to find
* the namespace objects.
*/
status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
if (ACPI_FAILURE(status) || !ec->handle) {
acpi_ec_free(ec);
return;
}
/*
* When the DSDT EC is available, always re-configure boot EC to
* have _REG evaluated. _REG can only be evaluated after the
* namespace initialization.
* At this point, the GPE is not fully initialized, so do not to
* handle the events.
*/
ret = acpi_ec_setup(ec, NULL, false);
if (ret) {
acpi_ec_free(ec);
return;
}
boot_ec = ec;
acpi_handle_info(ec->handle,
"Boot DSDT EC used to handle transactions\n");
}
/*
* If the DSDT EC is not functioning, we still need to prepare a fully
* functioning ECDT EC first in order to handle the events.
* https://bugzilla.kernel.org/show_bug.cgi?id=115021
*/
static int __init acpi_ec_ecdt_start(void)
{
acpi_handle handle;
if (!boot_ec)
return -ENODEV;
/* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
if (!boot_ec_is_ecdt)
return -ENODEV;
/*
* At this point, the namespace and the GPE is initialized, so
* start to find the namespace objects and handle the events.
*
* Note: ec->handle can be valid if this function is called after
* acpi_ec_add(), hence the fast path.
*/
if (boot_ec->handle == ACPI_ROOT_OBJECT) {
if (!acpi_ec_ecdt_get_handle(&handle))
return -ENODEV;
boot_ec->handle = handle;
}
/* Register to ACPI bus with PM ops attached */
return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
}
#if 0
/*
* Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
* set, for which case, we complete the QR_EC without issuing it to the
* firmware.
* https://bugzilla.kernel.org/show_bug.cgi?id=82611
* https://bugzilla.kernel.org/show_bug.cgi?id=97381
*/
static int ec_flag_query_handshake(const struct dmi_system_id *id)
{
pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
EC_FLAGS_QUERY_HANDSHAKE = 1;
return 0;
}
#endif
/*
* On some hardware it is necessary to clear events accumulated by the EC during
* sleep. These ECs stop reporting GPEs until they are manually polled, if too
* many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
*
* https://bugzilla.kernel.org/show_bug.cgi?id=44161
*
* Ideally, the EC should also be instructed NOT to accumulate events during
* sleep (which Windows seems to do somehow), but the interface to control this
* behaviour is not known at this time.
*
* Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
* however it is very likely that other Samsung models are affected.
*
* On systems which don't accumulate _Q events during sleep, this extra check
* should be harmless.
*/
static int ec_clear_on_resume(const struct dmi_system_id *id)
{
pr_debug("Detected system needing EC poll on resume.\n");
EC_FLAGS_CLEAR_ON_RESUME = 1;
ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
return 0;
}
/*
* Some ECDTs contain wrong register addresses.
* MSI MS-171F
* https://bugzilla.kernel.org/show_bug.cgi?id=12461
*/
static int ec_correct_ecdt(const struct dmi_system_id *id)
{
pr_debug("Detected system needing ECDT address correction.\n");
EC_FLAGS_CORRECT_ECDT = 1;
return 0;
}
/*
* Some DSDTs contain wrong GPE setting.
* Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
* https://bugzilla.kernel.org/show_bug.cgi?id=195651
*/
static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
{
pr_debug("Detected system needing ignore DSDT GPE setting.\n");
EC_FLAGS_IGNORE_DSDT_GPE = 1;
return 0;
}
static const struct dmi_system_id ec_dmi_table[] __initconst = {
{
ec_correct_ecdt, "MSI MS-171F", {
DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
{
ec_honor_ecdt_gpe, "ASUS FX502VD", {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
{
ec_honor_ecdt_gpe, "ASUS FX502VE", {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
{
ec_honor_ecdt_gpe, "ASUS GL702VMK", {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
{
ec_honor_ecdt_gpe, "ASUS X550VXK", {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
{
ec_honor_ecdt_gpe, "ASUS X580VD", {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
{
ec_clear_on_resume, "Samsung hardware", {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
{},
};
void __init acpi_ec_ecdt_probe(void)
{
struct acpi_table_ecdt *ecdt_ptr;
struct acpi_ec *ec;
acpi_status status;
int ret;
/* Generate a boot ec context. */
dmi_check_system(ec_dmi_table);
status = acpi_get_table(ACPI_SIG_ECDT, 1,
(struct acpi_table_header **)&ecdt_ptr);
if (ACPI_FAILURE(status))
return;
if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
/*
* Asus X50GL:
* https://bugzilla.kernel.org/show_bug.cgi?id=11880
*/
return;
}
ec = acpi_ec_alloc();
if (!ec)
return;
if (EC_FLAGS_CORRECT_ECDT) {
ec->command_addr = ecdt_ptr->data.address;
ec->data_addr = ecdt_ptr->control.address;
} else {
ec->command_addr = ecdt_ptr->control.address;
ec->data_addr = ecdt_ptr->data.address;
}
/*
* Ignore the GPE value on Reduced Hardware platforms.
* Some products have this set to an erroneous value.
*/
if (!acpi_gbl_reduced_hardware)
ec->gpe = ecdt_ptr->gpe;
ec->handle = ACPI_ROOT_OBJECT;
/*
* At this point, the namespace is not initialized, so do not find
* the namespace objects, or handle the events.
*/
ret = acpi_ec_setup(ec, NULL, false);
if (ret) {
acpi_ec_free(ec);
return;
}
boot_ec = ec;
boot_ec_is_ecdt = true;
pr_info("Boot ECDT EC used to handle transactions\n");
}
#ifdef CONFIG_PM_SLEEP
static int acpi_ec_suspend(struct device *dev)
{
struct acpi_ec *ec =
acpi_driver_data(to_acpi_device(dev));
if (!pm_suspend_no_platform() && ec_freeze_events)
acpi_ec_disable_event(ec);
return 0;
}
static int acpi_ec_suspend_noirq(struct device *dev)
{
struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
/*
* The SCI handler doesn't run at this point, so the GPE can be
* masked at the low level without side effects.
*/
if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
ec->gpe >= 0 && ec->reference_count >= 1)
acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
acpi_ec_enter_noirq(ec);
return 0;
}
static int acpi_ec_resume_noirq(struct device *dev)
{
struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
acpi_ec_leave_noirq(ec);
if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
ec->gpe >= 0 && ec->reference_count >= 1)
acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
return 0;
}
static int acpi_ec_resume(struct device *dev)
{
struct acpi_ec *ec =
acpi_driver_data(to_acpi_device(dev));
acpi_ec_enable_event(ec);
return 0;
}
void acpi_ec_mark_gpe_for_wake(void)
{
if (first_ec && !ec_no_wakeup)
acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
}
EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
void acpi_ec_set_gpe_wake_mask(u8 action)
{
if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
}
bool acpi_ec_dispatch_gpe(void)
{
u32 ret;
if (!first_ec)
return false;
ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
if (ret == ACPI_INTERRUPT_HANDLED) {
pm_pr_dbg("EC GPE dispatched\n");
return true;
}
return false;
}
#endif /* CONFIG_PM_SLEEP */
static const struct dev_pm_ops acpi_ec_pm = {
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
};
static int param_set_event_clearing(const char *val,
const struct kernel_param *kp)
{
int result = 0;
if (!strncmp(val, "status", sizeof("status") - 1)) {
ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
} else if (!strncmp(val, "query", sizeof("query") - 1)) {
ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
} else if (!strncmp(val, "event", sizeof("event") - 1)) {
ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
pr_info("Assuming SCI_EVT clearing on event reads\n");
} else
result = -EINVAL;
return result;
}
static int param_get_event_clearing(char *buffer,
const struct kernel_param *kp)
{
switch (ec_event_clearing) {
case ACPI_EC_EVT_TIMING_STATUS:
return sprintf(buffer, "status");
case ACPI_EC_EVT_TIMING_QUERY:
return sprintf(buffer, "query");
case ACPI_EC_EVT_TIMING_EVENT:
return sprintf(buffer, "event");
default:
return sprintf(buffer, "invalid");
}
return 0;
}
module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
NULL, 0644);
MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
static struct acpi_driver acpi_ec_driver = {
.name = "ec",
.class = ACPI_EC_CLASS,
.ids = ec_device_ids,
.ops = {
.add = acpi_ec_add,
.remove = acpi_ec_remove,
},
.drv.pm = &acpi_ec_pm,
};
static inline int acpi_ec_query_init(void)
{
if (!ec_query_wq) {
ec_query_wq = alloc_workqueue("kec_query", 0,
ec_max_queries);
if (!ec_query_wq)
return -ENODEV;
}
return 0;
}
static inline void acpi_ec_query_exit(void)
{
if (ec_query_wq) {
destroy_workqueue(ec_query_wq);
ec_query_wq = NULL;
}
}
static const struct dmi_system_id acpi_ec_no_wakeup[] = {
{
.ident = "Thinkpad X1 Carbon 6th",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
},
},
{
.ident = "ThinkPad X1 Carbon 6th",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
},
},
{
.ident = "ThinkPad X1 Yoga 3rd",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
},
},
{ },
};
int __init acpi_ec_init(void)
{
int result;
int ecdt_fail, dsdt_fail;
/* register workqueue for _Qxx evaluations */
result = acpi_ec_query_init();
if (result)
return result;
/*
* Disable EC wakeup on following systems to prevent periodic
* wakeup from EC GPE.
*/
if (dmi_check_system(acpi_ec_no_wakeup)) {
ec_no_wakeup = true;
pr_debug("Disabling EC wakeup on suspend-to-idle\n");
}
/* Drivers must be started after acpi_ec_query_init() */
dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
/*
* Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
* useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
* settings but invalid DSDT settings.
* https://bugzilla.kernel.org/show_bug.cgi?id=196847
*/
ecdt_fail = acpi_ec_ecdt_start();
return ecdt_fail && dsdt_fail ? -ENODEV : 0;
}
/* EC driver currently not unloadable */
#if 0
static void __exit acpi_ec_exit(void)
{
acpi_bus_unregister_driver(&acpi_ec_driver);
acpi_ec_query_exit();
}
#endif /* 0 */
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