ACPI: EC: do transaction from interrupt context (7c6db4e0) · Commits · 戴 / test

drivers/acpi/ec.c

+149 −160

Original line number	Diff line number	Diff line
		/*
		* ec.c - ACPI Embedded Controller Driver (v2.0)
		* ec.c - ACPI Embedded Controller Driver (v2.1)
		*
		* Copyright (C) 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
		* Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
		* Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
		* Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
		* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
		@@ -26,7 +26,7 @@
		* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		*/

		/* Uncomment next line to get verbose print outs*/
		/* Uncomment next line to get verbose printout */
		/* #define DEBUG */

		#include <linux/kernel.h>
		@@ -38,6 +38,7 @@
		#include <linux/seq_file.h>
		#include <linux/interrupt.h>
		#include <linux/list.h>
		#include <linux/spinlock.h>
		#include <asm/io.h>
		#include <acpi/acpi_bus.h>
		#include <acpi/acpi_drivers.h>
		@@ -65,22 +66,21 @@ enum ec_command {
		ACPI_EC_COMMAND_QUERY = 0x84,
		};

		/* EC events */
		enum ec_event {
		ACPI_EC_EVENT_OBF_1 = 1, /* Output buffer full */
		ACPI_EC_EVENT_IBF_0, /* Input buffer empty */
		};

		#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 100 /* Wait 100us before polling EC again */

		#define ACPI_EC_STORM_THRESHOLD 20 /* number of false interrupts
		per one transaction */

		enum {
		EC_FLAGS_WAIT_GPE = 0, /* Don't check status until GPE arrives */
		EC_FLAGS_QUERY_PENDING, /* Query is pending */
		EC_FLAGS_GPE_MODE, /* Expect GPE to be sent for status change */
		EC_FLAGS_GPE_MODE, /* Expect GPE to be sent
		* for status change */
		EC_FLAGS_NO_GPE, /* Don't use GPE mode */
		EC_FLAGS_RESCHEDULE_POLL /* Re-schedule poll */
		EC_FLAGS_GPE_STORM, /* GPE storm detected */
		EC_FLAGS_HANDLERS_INSTALLED /* Handlers for GPE and
		* OpReg are installed */
		};

		/* If we find an EC via the ECDT, we need to keep a ptr to its context */
		@@ -95,6 +95,14 @@ struct acpi_ec_query_handler {
		u8 query_bit;
		};

		struct transaction_data {
		const u8 *wdata;
		u8 *rdata;
		unsigned short irq_count;
		u8 wlen;
		u8 rlen;
		};

		static struct acpi_ec {
		acpi_handle handle;
		unsigned long gpe;
		@@ -105,9 +113,8 @@ static struct acpi_ec {
		struct mutex lock;
		wait_queue_head_t wait;
		struct list_head list;
		struct delayed_work work;
		atomic_t irq_count;
		u8 handlers_installed;
		struct transaction_data *t;
		spinlock_t t_lock;
		} boot_ec, first_ec;

		/*
		@@ -150,7 +157,7 @@ static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
		{
		u8 x = inb(ec->data_addr);
		pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
		return inb(ec->data_addr);
		return x;
		}

		static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
		@@ -165,68 +172,79 @@ static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
		outb(data, ec->data_addr);
		}

		static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
		static int ec_transaction_done(struct acpi_ec *ec)
		{
		if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
		return 0;
		if (event == ACPI_EC_EVENT_OBF_1) {
		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
		return 1;
		} else if (event == ACPI_EC_EVENT_IBF_0) {
		if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
		return 1;
		}

		return 0;
		unsigned long flags;
		int ret = 0;
		spin_lock_irqsave(&ec->t_lock, flags);
		if (!ec->t \|\| (!ec->t->wlen && !ec->t->rlen))
		ret = 1;
		spin_unlock_irqrestore(&ec->t_lock, flags);
		return ret;
		}

		static void ec_schedule_ec_poll(struct acpi_ec *ec)
		static void gpe_transaction(struct acpi_ec *ec, u8 status)
		{
		if (test_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags))
		schedule_delayed_work(&ec->work,
		msecs_to_jiffies(ACPI_EC_DELAY));
		}
		unsigned long flags;
		spin_lock_irqsave(&ec->t_lock, flags);
		if (!ec->t)
		goto unlock;
		if (ec->t->wlen > 0) {
		if ((status & ACPI_EC_FLAG_IBF) == 0) {
		acpi_ec_write_data(ec, *(ec->t->wdata++));
		--ec->t->wlen;
		} else
		/* false interrupt, state didn't change */
		++ec->t->irq_count;

		static void ec_switch_to_poll_mode(struct acpi_ec *ec)
		{
		set_bit(EC_FLAGS_NO_GPE, &ec->flags);
		clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
		acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
		set_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
		} else if (ec->t->rlen > 0) {
		if ((status & ACPI_EC_FLAG_OBF) == 1) {
		*(ec->t->rdata++) = acpi_ec_read_data(ec);
		--ec->t->rlen;
		} else
		/* false interrupt, state didn't change */
		++ec->t->irq_count;
		}
		unlock:
		spin_unlock_irqrestore(&ec->t_lock, flags);
		}

		static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
		static int acpi_ec_wait(struct acpi_ec *ec)
		{
		atomic_set(&ec->irq_count, 0);
		if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
		likely(!force_poll)) {
		if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
		if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
		msecs_to_jiffies(ACPI_EC_DELAY)))
		return 0;
		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
		if (acpi_ec_check_status(ec, event)) {
		/* missing GPEs, switch back to poll mode */
		if (printk_ratelimit())
		pr_info(PREFIX "missing confirmations, "
		"switch off interrupt mode.\n");
		ec_switch_to_poll_mode(ec);
		ec_schedule_ec_poll(ec);
		set_bit(EC_FLAGS_NO_GPE, &ec->flags);
		clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
		return 1;
		}

		static void acpi_ec_gpe_query(void *ec_cxt);

		static int ec_check_sci(struct acpi_ec *ec, u8 state)
		{
		if (state & ACPI_EC_FLAG_SCI) {
		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
		return acpi_os_execute(OSL_EC_BURST_HANDLER,
		acpi_ec_gpe_query, ec);
		}
		return 0;
		}
		} else {

		static int ec_poll(struct acpi_ec *ec)
		{
		unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
		msleep(1);
		while (time_before(jiffies, delay)) {
		if (acpi_ec_check_status(ec, event))
		return 0;
		gpe_transaction(ec, acpi_ec_read_status(ec));
		msleep(1);
		}
		if (acpi_ec_check_status(ec,event))
		if (ec_transaction_done(ec))
		return 0;
		}
		pr_err(PREFIX "acpi_ec_wait timeout, status = 0x%2.2x, event = %s\n",
		acpi_ec_read_status(ec),
		(event == ACPI_EC_EVENT_OBF_1) ? "\"b0=1\"" : "\"b1=0\"");
		return -ETIME;
		}

		@@ -235,45 +253,51 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
		u8 * rdata, unsigned rdata_len,
		int force_poll)
		{
		int result = 0;
		set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
		unsigned long tmp;
		struct transaction_data t = {.wdata = wdata, .rdata = rdata,
		.wlen = wdata_len, .rlen = rdata_len,
		.irq_count = 0};
		int ret = 0;
		pr_debug(PREFIX "transaction start\n");
		acpi_ec_write_cmd(ec, command);
		for (; wdata_len > 0; --wdata_len) {
		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
		if (result) {
		pr_err(PREFIX
		"write_cmd timeout, command = %d\n", command);
		goto end;
		}
		set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
		acpi_ec_write_data(ec, *(wdata++));
		}

		if (!rdata_len) {
		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
		if (result) {
		pr_err(PREFIX
		"finish-write timeout, command = %d\n", command);
		goto end;
		/* disable GPE during transaction if storm is detected */
		if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
		clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
		acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
		}
		} else if (command == ACPI_EC_COMMAND_QUERY)
		/* start transaction */
		spin_lock_irqsave(&ec->t_lock, tmp);
		/* following two actions should be kept atomic */
		ec->t = &t;
		acpi_ec_write_cmd(ec, command);
		if (command == ACPI_EC_COMMAND_QUERY)
		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);

		for (; rdata_len > 0; --rdata_len) {
		result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
		if (result) {
		pr_err(PREFIX "read timeout, command = %d\n", command);
		goto end;
		spin_unlock_irqrestore(&ec->t_lock, tmp);
		/* if we selected poll mode or failed in GPE-mode do a poll loop */
		if (force_poll \|\|
		!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) \|\|
		acpi_ec_wait(ec))
		ret = ec_poll(ec);
		pr_debug(PREFIX "transaction end\n");
		spin_lock_irqsave(&ec->t_lock, tmp);
		ec->t = NULL;
		spin_unlock_irqrestore(&ec->t_lock, tmp);
		if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
		/* check if we received SCI during transaction */
		ec_check_sci(ec, acpi_ec_read_status(ec));
		/* it is safe to enable GPE outside of transaction */
		acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
		} else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
		t.irq_count > ACPI_EC_STORM_THRESHOLD) {
		pr_debug(PREFIX "GPE storm detected\n");
		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
		}
		/* Don't expect GPE after last read */
		if (rdata_len > 1)
		set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
		*(rdata++) = acpi_ec_read_data(ec);
		return ret;
		}
		end:
		pr_debug(PREFIX "transaction end\n");
		return result;

		static int ec_check_ibf0(struct acpi_ec *ec)
		{
		u8 status = acpi_ec_read_status(ec);
		return (status & ACPI_EC_FLAG_IBF) == 0;
		}

		static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
		@@ -283,40 +307,34 @@ static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
		{
		int status;
		u32 glk;

		if (!ec \|\| (wdata_len && !wdata) \|\| (rdata_len && !rdata))
		return -EINVAL;

		if (rdata)
		memset(rdata, 0, rdata_len);

		mutex_lock(&ec->lock);
		if (ec->global_lock) {
		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
		if (ACPI_FAILURE(status)) {
		mutex_unlock(&ec->lock);
		return -ENODEV;
		status = -ENODEV;
		goto unlock;
		}
		}

		status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
		if (status) {
		if (!wait_event_timeout(ec->wait, ec_check_ibf0(ec),
		msecs_to_jiffies(ACPI_EC_DELAY))) {
		pr_err(PREFIX "input buffer is not empty, "
		"aborting transaction\n");
		status = -ETIME;
		goto end;
		}

		status = acpi_ec_transaction_unlocked(ec, command,
		wdata, wdata_len,
		rdata, rdata_len,
		force_poll);

		end:

		if (ec->global_lock)
		acpi_release_global_lock(glk);
		unlock:
		mutex_unlock(&ec->lock);

		return status;
		}

		@@ -332,7 +350,9 @@ int acpi_ec_burst_enable(struct acpi_ec *ec)

		int acpi_ec_burst_disable(struct acpi_ec *ec)
		{
		return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
		return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
		acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE,
		NULL, 0, NULL, 0, 0) : 0;
		}

		static int acpi_ec_read(struct acpi_ec ec, u8 address, u8 data)
		@@ -513,46 +533,26 @@ static void acpi_ec_gpe_query(void *ec_cxt)

		static u32 acpi_ec_gpe_handler(void *data)
		{
		acpi_status status = AE_OK;
		struct acpi_ec *ec = data;
		u8 state = acpi_ec_read_status(ec);
		u8 status;

		pr_debug(PREFIX "~~~> interrupt\n");
		atomic_inc(&ec->irq_count);
		if (atomic_read(&ec->irq_count) > 5) {
		pr_err(PREFIX "GPE storm detected, disabling EC GPE\n");
		ec_switch_to_poll_mode(ec);
		goto end;
		}
		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
		if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
		status = acpi_ec_read_status(ec);

		gpe_transaction(ec, status);
		if (ec_transaction_done(ec) && (status & ACPI_EC_FLAG_IBF) == 0)
		wake_up(&ec->wait);

		if (state & ACPI_EC_FLAG_SCI) {
		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
		status = acpi_os_execute(OSL_EC_BURST_HANDLER,
		acpi_ec_gpe_query, ec);
		} else if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
		!test_bit(EC_FLAGS_NO_GPE, &ec->flags) &&
		in_interrupt()) {
		ec_check_sci(ec, status);
		if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
		!test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
		/* this is non-query, must be confirmation */
		if (printk_ratelimit())
		pr_info(PREFIX "non-query interrupt received,"
		" switching to interrupt mode\n");
		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
		clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
		}
		end:
		ec_schedule_ec_poll(ec);
		return ACPI_SUCCESS(status) ?
		ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
		}

		static void do_ec_poll(struct work_struct *work)
		{
		struct acpi_ec *ec = container_of(work, struct acpi_ec, work.work);
		atomic_set(&ec->irq_count, 0);
		(void)acpi_ec_gpe_handler(ec);
		return ACPI_INTERRUPT_HANDLED;
		}

		/* --------------------------------------------------------------------------
		@@ -696,8 +696,7 @@ static struct acpi_ec *make_acpi_ec(void)
		mutex_init(&ec->lock);
		init_waitqueue_head(&ec->wait);
		INIT_LIST_HEAD(&ec->list);
		INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);
		atomic_set(&ec->irq_count, 0);
		spin_lock_init(&ec->t_lock);
		return ec;
		}

		@@ -736,22 +735,15 @@ ec_parse_device(acpi_handle handle, u32 Level, void context, void *retval)
		return AE_CTRL_TERMINATE;
		}

		static void ec_poll_stop(struct acpi_ec *ec)
		{
		clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
		cancel_delayed_work(&ec->work);
		}

		static void ec_remove_handlers(struct acpi_ec *ec)
		{
		ec_poll_stop(ec);
		if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
		ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
		pr_err(PREFIX "failed to remove space handler\n");
		if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
		&acpi_ec_gpe_handler)))
		pr_err(PREFIX "failed to remove gpe handler\n");
		ec->handlers_installed = 0;
		clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
		}

		static int acpi_ec_add(struct acpi_device *device)
		@@ -846,17 +838,15 @@ ec_parse_io_ports(struct acpi_resource resource, void context)
		static int ec_install_handlers(struct acpi_ec *ec)
		{
		acpi_status status;
		if (ec->handlers_installed)
		if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
		return 0;
		status = acpi_install_gpe_handler(NULL, ec->gpe,
		ACPI_GPE_EDGE_TRIGGERED,
		&acpi_ec_gpe_handler, ec);
		if (ACPI_FAILURE(status))
		return -ENODEV;

		acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
		acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);

		status = acpi_install_address_space_handler(ec->handle,
		ACPI_ADR_SPACE_EC,
		&acpi_ec_space_handler,
		@@ -866,7 +856,7 @@ static int ec_install_handlers(struct acpi_ec *ec)
		return -ENODEV;
		}

		ec->handlers_installed = 1;
		set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
		return 0;
		}

		@@ -887,7 +877,6 @@ static int acpi_ec_start(struct acpi_device *device)

		/* EC is fully operational, allow queries */
		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
		ec_schedule_ec_poll(ec);
		return ret;
		}

		@@ -906,7 +895,7 @@ static int acpi_ec_stop(struct acpi_device *device, int type)

		int __init acpi_boot_ec_enable(void)
		{
		if (!boot_ec \|\| boot_ec->handlers_installed)
		if (!boot_ec \|\| test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
		return 0;
		if (!ec_install_handlers(boot_ec)) {
		first_ec = boot_ec;

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