ACPICA: hw: remove use_lock flag from acpi_hw_register_{read, write}

use_lock flag is used once for acpi_hw_register_read, and never for
acpi_hw_register_write. It will greatly simplify understanding of
locking if we just drop this use_lock altogether, and wrap the only call
to ..._read in lock/unlock.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 35 insertions, 54 deletions

diff --git a/drivers/acpi/hardware/hwregs.c b/drivers/acpi/hardware/hwregs.c
index 1d371fa663f..73f9c5fb1ba 100644
--- a/drivers/acpi/hardware/hwregs.c
+++ b/drivers/acpi/hardware/hwregs.c
@@ -75,8 +75,7 @@ acpi_status acpi_hw_clear_acpi_status(void)
 
 	lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
 
-	status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK,
-					ACPI_REGISTER_PM1_STATUS,
+	status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
 					ACPI_BITMASK_ALL_FIXED_STATUS);
 	if (ACPI_FAILURE(status)) {
 		goto unlock_and_exit;
@@ -259,7 +258,7 @@ struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id)
  *
  ******************************************************************************/
 
-acpi_status acpi_get_register(u32 register_id, u32 * return_value)
+acpi_status acpi_get_register_unlocked(u32 register_id, u32 * return_value)
 {
 	u32 register_value = 0;
 	struct acpi_bit_register_info *bit_reg_info;
@@ -276,8 +275,7 @@ acpi_status acpi_get_register(u32 register_id, u32 * return_value)
 
 	/* Read from the register */
 
-	status = acpi_hw_register_read(ACPI_MTX_LOCK,
-				       bit_reg_info->parent_register,
+	status = acpi_hw_register_read(bit_reg_info->parent_register,
 				       &register_value);
 
 	if (ACPI_SUCCESS(status)) {
@@ -298,6 +296,16 @@ acpi_status acpi_get_register(u32 register_id, u32 * return_value)
 	return_ACPI_STATUS(status);
 }
 
+acpi_status acpi_get_register(u32 register_id, u32 * return_value)
+{
+	acpi_status status;
+	acpi_cpu_flags flags;
+	flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+	status = acpi_get_register_unlocked(register_id, return_value);
+	acpi_os_release_lock(acpi_gbl_hardware_lock, flags);
+	return status;
+}
+
 ACPI_EXPORT_SYMBOL(acpi_get_register)
 
 /*******************************************************************************
@@ -335,8 +343,7 @@ acpi_status acpi_set_register(u32 register_id, u32 value)
 
 	/* Always do a register read first so we can insert the new bits  */
 
-	status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK,
-				       bit_reg_info->parent_register,
+	status = acpi_hw_register_read(bit_reg_info->parent_register,
 				       &register_value);
 	if (ACPI_FAILURE(status)) {
 		goto unlock_and_exit;
@@ -363,8 +370,7 @@ acpi_status acpi_set_register(u32 register_id, u32 value)
 						   bit_reg_info->
 						   access_bit_mask);
 		if (value) {
-			status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK,
-							ACPI_REGISTER_PM1_STATUS,
+			status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
 							(u16) value);
 			register_value = 0;
 		}
@@ -377,8 +383,7 @@ acpi_status acpi_set_register(u32 register_id, u32 value)
 					   bit_reg_info->access_bit_mask,
 					   value);
 
-		status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK,
-						ACPI_REGISTER_PM1_ENABLE,
+		status = acpi_hw_register_write(ACPI_REGISTER_PM1_ENABLE,
 						(u16) register_value);
 		break;
 
@@ -397,15 +402,13 @@ acpi_status acpi_set_register(u32 register_id, u32 value)
 					   bit_reg_info->access_bit_mask,
 					   value);
 
-		status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK,
-						ACPI_REGISTER_PM1_CONTROL,
+		status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
 						(u16) register_value);
 		break;
 
 	case ACPI_REGISTER_PM2_CONTROL:
 
-		status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK,
-					       ACPI_REGISTER_PM2_CONTROL,
+		status = acpi_hw_register_read(ACPI_REGISTER_PM2_CONTROL,
 					       &register_value);
 		if (ACPI_FAILURE(status)) {
 			goto unlock_and_exit;
@@ -430,8 +433,7 @@ acpi_status acpi_set_register(u32 register_id, u32 value)
 						     xpm2_control_block.
 						     address)));
 
-		status = acpi_hw_register_write(ACPI_MTX_DO_NOT_LOCK,
-						ACPI_REGISTER_PM2_CONTROL,
+		status = acpi_hw_register_write(ACPI_REGISTER_PM2_CONTROL,
 						(u8) (register_value));
 		break;
 
@@ -461,8 +463,7 @@ ACPI_EXPORT_SYMBOL(acpi_set_register)
  *
  * FUNCTION:    acpi_hw_register_read
  *
- * PARAMETERS:  use_lock            - Lock hardware? True/False
- *              register_id         - ACPI Register ID
+ * PARAMETERS:  register_id         - ACPI Register ID
  *              return_value        - Where the register value is returned
  *
  * RETURN:      Status and the value read.
@@ -471,19 +472,14 @@ ACPI_EXPORT_SYMBOL(acpi_set_register)
  *
  ******************************************************************************/
 acpi_status
-acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value)
+acpi_hw_register_read(u32 register_id, u32 * return_value)
 {
 	u32 value1 = 0;
 	u32 value2 = 0;
 	acpi_status status;
-	acpi_cpu_flags lock_flags = 0;
 
 	ACPI_FUNCTION_TRACE(hw_register_read);
 
-	if (ACPI_MTX_LOCK == use_lock) {
-		lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
-	}
-
 	switch (register_id) {
 	case ACPI_REGISTER_PM1_STATUS:	/* 16-bit access */
 
@@ -491,7 +487,7 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value)
 		    acpi_hw_low_level_read(16, &value1,
 					   &acpi_gbl_FADT.xpm1a_event_block);
 		if (ACPI_FAILURE(status)) {
-			goto unlock_and_exit;
+			goto exit;
 		}
 
 		/* PM1B is optional */
@@ -507,7 +503,7 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value)
 		status =
 		    acpi_hw_low_level_read(16, &value1, &acpi_gbl_xpm1a_enable);
 		if (ACPI_FAILURE(status)) {
-			goto unlock_and_exit;
+			goto exit;
 		}
 
 		/* PM1B is optional */
@@ -523,7 +519,7 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value)
 		    acpi_hw_low_level_read(16, &value1,
 					   &acpi_gbl_FADT.xpm1a_control_block);
 		if (ACPI_FAILURE(status)) {
-			goto unlock_and_exit;
+			goto exit;
 		}
 
 		status =
@@ -558,10 +554,7 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value)
 		break;
 	}
 
-      unlock_and_exit:
-	if (ACPI_MTX_LOCK == use_lock) {
-		acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
-	}
+      exit:
 
 	if (ACPI_SUCCESS(status)) {
 		*return_value = value1;
@@ -574,8 +567,7 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value)
  *
  * FUNCTION:    acpi_hw_register_write
  *
- * PARAMETERS:  use_lock            - Lock hardware? True/False
- *              register_id         - ACPI Register ID
+ * PARAMETERS:  register_id         - ACPI Register ID
  *              Value               - The value to write
  *
  * RETURN:      Status
@@ -597,28 +589,22 @@ acpi_hw_register_read(u8 use_lock, u32 register_id, u32 * return_value)
  *
  ******************************************************************************/
 
-acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value)
+acpi_status acpi_hw_register_write(u32 register_id, u32 value)
 {
 	acpi_status status;
-	acpi_cpu_flags lock_flags = 0;
 	u32 read_value;
 
 	ACPI_FUNCTION_TRACE(hw_register_write);
 
-	if (ACPI_MTX_LOCK == use_lock) {
-		lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
-	}
-
 	switch (register_id) {
 	case ACPI_REGISTER_PM1_STATUS:	/* 16-bit access */
 
 		/* Perform a read first to preserve certain bits (per ACPI spec) */
 
-		status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK,
-					       ACPI_REGISTER_PM1_STATUS,
+		status = acpi_hw_register_read(ACPI_REGISTER_PM1_STATUS,
 					       &read_value);
 		if (ACPI_FAILURE(status)) {
-			goto unlock_and_exit;
+			goto exit;
 		}
 
 		/* Insert the bits to be preserved */
@@ -632,7 +618,7 @@ acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value)
 		    acpi_hw_low_level_write(16, value,
 					    &acpi_gbl_FADT.xpm1a_event_block);
 		if (ACPI_FAILURE(status)) {
-			goto unlock_and_exit;
+			goto exit;
 		}
 
 		/* PM1B is optional */
@@ -647,7 +633,7 @@ acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value)
 		status =
 		    acpi_hw_low_level_write(16, value, &acpi_gbl_xpm1a_enable);
 		if (ACPI_FAILURE(status)) {
-			goto unlock_and_exit;
+			goto exit;
 		}
 
 		/* PM1B is optional */
@@ -661,11 +647,10 @@ acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value)
 		/*
 		 * Perform a read first to preserve certain bits (per ACPI spec)
 		 */
-		status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK,
-					       ACPI_REGISTER_PM1_CONTROL,
+		status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
 					       &read_value);
 		if (ACPI_FAILURE(status)) {
-			goto unlock_and_exit;
+			goto exit;
 		}
 
 		/* Insert the bits to be preserved */
@@ -679,7 +664,7 @@ acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value)
 		    acpi_hw_low_level_write(16, value,
 					    &acpi_gbl_FADT.xpm1a_control_block);
 		if (ACPI_FAILURE(status)) {
-			goto unlock_and_exit;
+			goto exit;
 		}
 
 		status =
@@ -728,11 +713,7 @@ acpi_status acpi_hw_register_write(u8 use_lock, u32 register_id, u32 value)
 		break;
 	}
 
-      unlock_and_exit:
-	if (ACPI_MTX_LOCK == use_lock) {
-		acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
-	}
-
+      exit:
 	return_ACPI_STATUS(status);
 }