ACPI: EC: Replace atomic variables with bits

Number of flags is about to be increased, so it is better to
put them all into bits.
No functional changes.
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/ec.c

@@ -65,7 +65,7 @@ enum ec_command {
 /* EC events */
 enum ec_event {
 	ACPI_EC_EVENT_OBF_1 = 1,	/* Output buffer full */
-	ACPI_EC_EVENT_IBF_0,	/* Input buffer empty */
+	ACPI_EC_EVENT_IBF_0,		/* Input buffer empty */
 };
 
 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
@@ -76,6 +76,11 @@ static enum ec_mode {
 	EC_POLL,		/* Input buffer empty */
 } acpi_ec_mode = EC_INTR;
 
+enum {
+	EC_FLAGS_WAIT_GPE = 0,		/* Don't check status until GPE arrives */
+	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
+};
+
 static int acpi_ec_remove(struct acpi_device *device, int type);
 static int acpi_ec_start(struct acpi_device *device);
 static int acpi_ec_stop(struct acpi_device *device, int type);
@@ -116,9 +121,8 @@ static struct acpi_ec {
 	unsigned long command_addr;
 	unsigned long data_addr;
 	unsigned long global_lock;
+	unsigned long flags;
 	struct mutex lock;
-	atomic_t query_pending;
-	atomic_t event_count;
 	wait_queue_head_t wait;
 	struct list_head list;
 	u8 handlers_installed;
@@ -148,45 +152,42 @@ 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,
-				       unsigned old_count)
+static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 {
-	u8 status = acpi_ec_read_status(ec);
-	if (old_count == atomic_read(&ec->event_count))
+	if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
 		return 0;
 	if (event == ACPI_EC_EVENT_OBF_1) {
-		if (status & ACPI_EC_FLAG_OBF)
+		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
 			return 1;
 	} else if (event == ACPI_EC_EVENT_IBF_0) {
-		if (!(status & ACPI_EC_FLAG_IBF))
+		if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
 			return 1;
 	}
 
 	return 0;
 }
 
-static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event,
-                        unsigned count, int force_poll)
+static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 {
 	if (unlikely(force_poll) || acpi_ec_mode == EC_POLL) {
 		unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
+		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 		while (time_before(jiffies, delay)) {
-			if (acpi_ec_check_status(ec, event, 0))
+			if (acpi_ec_check_status(ec, event))
 				return 0;
 		}
 	} else {
-		if (wait_event_timeout(ec->wait,
-				       acpi_ec_check_status(ec, event, count),
-				       msecs_to_jiffies(ACPI_EC_DELAY)) ||
-		    acpi_ec_check_status(ec, event, 0)) {
+		if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
+				       msecs_to_jiffies(ACPI_EC_DELAY)))
+			return 0;
+		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
+		if (acpi_ec_check_status(ec, event)) {
 			return 0;
-		} else {
-			printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
-			       " status = %d, expect_event = %d\n",
-			       acpi_ec_read_status(ec), event);
 		}
 	}
-
+	printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
+			       " status = %d, expect_event = %d\n",
+			       acpi_ec_read_status(ec), event);
 	return -ETIME;
 }
 
@@ -196,39 +197,38 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 					int force_poll)
 {
 	int result = 0;
-	unsigned count = atomic_read(&ec->event_count);
+	set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 	acpi_ec_write_cmd(ec, command);
 
 	for (; wdata_len > 0; --wdata_len) {
-		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
+		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 		if (result) {
 			printk(KERN_ERR PREFIX
 			       "write_cmd timeout, command = %d\n", command);
 			goto end;
 		}
-		count = atomic_read(&ec->event_count);
+		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, count, force_poll);
+		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 		if (result) {
 			printk(KERN_ERR PREFIX
 			       "finish-write timeout, command = %d\n", command);
 			goto end;
 		}
-	} else if (command == ACPI_EC_COMMAND_QUERY) {
-		atomic_set(&ec->query_pending, 0);
-	}
+	} else 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, count, force_poll);
+		result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
 		if (result) {
 			printk(KERN_ERR PREFIX "read timeout, command = %d\n",
 			       command);
 			goto end;
 		}
-		count = atomic_read(&ec->event_count);
+		set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 		*(rdata++) = acpi_ec_read_data(ec);
 	}
       end:
@@ -261,7 +261,7 @@ static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 	/* Make sure GPE is enabled before doing transaction */
 	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 
-	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0, 0);
+	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
 	if (status) {
 		printk(KERN_ERR PREFIX
 		       "input buffer is not empty, aborting transaction\n");
@@ -476,20 +476,18 @@ static void acpi_ec_gpe_query(void *ec_cxt)
 static u32 acpi_ec_gpe_handler(void *data)
 {
 	acpi_status status = AE_OK;
-	u8 value;
 	struct acpi_ec *ec = data;
 
-	atomic_inc(&ec->event_count);
+	clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 
 	if (acpi_ec_mode == EC_INTR) {
 		wake_up(&ec->wait);
 	}
 
-	value = acpi_ec_read_status(ec);
-	if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
-		atomic_set(&ec->query_pending, 1);
-		status =
-		    acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query, ec);
+	if (acpi_ec_read_status(ec) & 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);
 	}
 
 	return status == AE_OK ?
@@ -642,8 +640,7 @@ static struct acpi_ec *make_acpi_ec(void)
 	if (!ec)
 		return NULL;
 
-	atomic_set(&ec->query_pending, 1);
-	atomic_set(&ec->event_count, 1);
+	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 	mutex_init(&ec->lock);
 	init_waitqueue_head(&ec->wait);
 	INIT_LIST_HEAD(&ec->list);
@@ -833,7 +830,7 @@ static int acpi_ec_start(struct acpi_device *device)
 	ret = ec_install_handlers(ec);
 
 	/* EC is fully operational, allow queries */
-	atomic_set(&ec->query_pending, 0);
+	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 	return ret;
 }