hwregs.c

xen虚拟机源代码安装包

	case ACPI_REGISTER_PM1_CONTROL:	/* 16-bit access */

		status =
		    acpi_hw_low_level_read(16, &value1,
					   &acpi_gbl_FADT.xpm1a_control_block);
		if (ACPI_FAILURE(status)) {
			goto exit;
		}

		status =
		    acpi_hw_low_level_read(16, &value2,
					   &acpi_gbl_FADT.xpm1b_control_block);
		value1 |= value2;
		break;

	case ACPI_REGISTER_PM2_CONTROL:	/* 8-bit access */

		status =
		    acpi_hw_low_level_read(8, &value1,
					   &acpi_gbl_FADT.xpm2_control_block);
		break;

	case ACPI_REGISTER_PM_TIMER:	/* 32-bit access */

		status =
		    acpi_hw_low_level_read(32, &value1,
					   &acpi_gbl_FADT.xpm_timer_block);
		break;

	case ACPI_REGISTER_SMI_COMMAND_BLOCK:	/* 8-bit access */

		status =
		    acpi_os_read_port(acpi_gbl_FADT.smi_command, &value1, 8);
		break;

	default:
		ACPI_DEBUG_PRINT((AE_INFO, "Unknown Register ID: %X", register_id));
		status = AE_BAD_PARAMETER;
		break;
	}

      exit:

	if (ACPI_SUCCESS(status)) {
		*return_value = value1;
	}

	return_ACPI_STATUS(status);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_hw_register_write
 *
 * PARAMETERS:  register_id         - ACPI Register ID
 *              Value               - The value to write
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Write to the specified ACPI register
 *
 * NOTE: In accordance with the ACPI specification, this function automatically
 * preserves the value of the following bits, meaning that these bits cannot be
 * changed via this interface:
 *
 * PM1_CONTROL[0] = SCI_EN
 * PM1_CONTROL[9]
 * PM1_STATUS[11]
 *
 * ACPI References:
 * 1) Hardware Ignored Bits: When software writes to a register with ignored
 *      bit fields, it preserves the ignored bit fields
 * 2) SCI_EN: OSPM always preserves this bit position
 *
 ******************************************************************************/

acpi_status acpi_hw_register_write(u32 register_id, u32 value)
{
	acpi_status status;
	u32 read_value;

	ACPI_FUNCTION_TRACE(hw_register_write);

	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_REGISTER_PM1_STATUS,
					       &read_value);
		if (ACPI_FAILURE(status)) {
			goto exit;
		}

		/* Insert the bits to be preserved */

		ACPI_INSERT_BITS(value, ACPI_PM1_STATUS_PRESERVED_BITS,
				 read_value);

		/* Now we can write the data */

		status =
		    acpi_hw_low_level_write(16, value,
					    &acpi_gbl_FADT.xpm1a_event_block);
		if (ACPI_FAILURE(status)) {
			goto exit;
		}

		/* PM1B is optional */

		status =
		    acpi_hw_low_level_write(16, value,
					    &acpi_gbl_FADT.xpm1b_event_block);
		break;

	case ACPI_REGISTER_PM1_ENABLE:	/* 16-bit access */

		status =
		    acpi_hw_low_level_write(16, value, &acpi_gbl_xpm1a_enable);
		if (ACPI_FAILURE(status)) {
			goto exit;
		}

		/* PM1B is optional */

		status =
		    acpi_hw_low_level_write(16, value, &acpi_gbl_xpm1b_enable);
		break;

	case ACPI_REGISTER_PM1_CONTROL:	/* 16-bit access */

		/*
		 * Perform a read first to preserve certain bits (per ACPI spec)
		 */
		status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
					       &read_value);
		if (ACPI_FAILURE(status)) {
			goto exit;
		}

		/* Insert the bits to be preserved */

		ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS,
				 read_value);

		/* Now we can write the data */

		status =
		    acpi_hw_low_level_write(16, value,
					    &acpi_gbl_FADT.xpm1a_control_block);
		if (ACPI_FAILURE(status)) {
			goto exit;
		}

		status =
		    acpi_hw_low_level_write(16, value,
					    &acpi_gbl_FADT.xpm1b_control_block);
		break;

	case ACPI_REGISTER_PM1A_CONTROL:	/* 16-bit access */

		status =
		    acpi_hw_low_level_write(16, value,
					    &acpi_gbl_FADT.xpm1a_control_block);
		break;

	case ACPI_REGISTER_PM1B_CONTROL:	/* 16-bit access */

		status =
		    acpi_hw_low_level_write(16, value,
					    &acpi_gbl_FADT.xpm1b_control_block);
		break;

	case ACPI_REGISTER_PM2_CONTROL:	/* 8-bit access */

		status =
		    acpi_hw_low_level_write(8, value,
					    &acpi_gbl_FADT.xpm2_control_block);
		break;

	case ACPI_REGISTER_PM_TIMER:	/* 32-bit access */

		status =
		    acpi_hw_low_level_write(32, value,
					    &acpi_gbl_FADT.xpm_timer_block);
		break;

	case ACPI_REGISTER_SMI_COMMAND_BLOCK:	/* 8-bit access */

		/* SMI_CMD is currently always in IO space */

		status =
		    acpi_os_write_port(acpi_gbl_FADT.smi_command, value, 8);
		break;

	default:
		status = AE_BAD_PARAMETER;
		break;
	}

      exit:
	return_ACPI_STATUS(status);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_hw_low_level_read
 *
 * PARAMETERS:  Width               - 8, 16, or 32
 *              Value               - Where the value is returned
 *              Reg                 - GAS register structure
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Read from either memory or IO space.
 *
 ******************************************************************************/

acpi_status
acpi_hw_low_level_read(u32 width, u32 * value, struct acpi_generic_address *reg)
{
	u64 address;
	acpi_status status;

	ACPI_FUNCTION_NAME(hw_low_level_read);

	/*
	 * Must have a valid pointer to a GAS structure, and
	 * a non-zero address within. However, don't return an error
	 * because the PM1A/B code must not fail if B isn't present.
	 */
	if (!reg) {
		return (AE_OK);
	}

	/* Get a local copy of the address. Handles possible alignment issues */

	ACPI_MOVE_64_TO_64(&address, &reg->address);
	if (!address) {
		return (AE_OK);
	}
	*value = 0;

	/*
	 * Two address spaces supported: Memory or IO.
	 * PCI_Config is not supported here because the GAS struct is insufficient
	 */
	switch (reg->space_id) {
	case ACPI_ADR_SPACE_SYSTEM_MEMORY:

		status = acpi_os_read_memory((acpi_physical_address) address,
					     value, width);
		break;

	case ACPI_ADR_SPACE_SYSTEM_IO:

		status = acpi_os_read_port((acpi_io_address) address,
					   value, width);
		break;

	default:

		return (AE_BAD_PARAMETER);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_IO,
			  "Read:  %8.8X width %2d from %8.8X%8.8X (%s)\n",
			  *value, width,
			  ACPI_FORMAT_UINT64(address),
			  acpi_ut_get_region_name(reg->address_space_id)));

	return (status);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_hw_low_level_write
 *
 * PARAMETERS:  Width               - 8, 16, or 32
 *              Value               - To be written
 *              Reg                 - GAS register structure
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Write to either memory or IO space.
 *
 ******************************************************************************/

acpi_status
acpi_hw_low_level_write(u32 width, u32 value, struct acpi_generic_address * reg)
{
	u64 address;
	acpi_status status;

	ACPI_FUNCTION_NAME(hw_low_level_write);

	/*
	 * Must have a valid pointer to a GAS structure, and
	 * a non-zero address within. However, don't return an error
	 * because the PM1A/B code must not fail if B isn't present.
	 */
	if (!reg) {
		return (AE_OK);
	}

	/* Get a local copy of the address. Handles possible alignment issues */

	ACPI_MOVE_64_TO_64(&address, &reg->address);
	if (!address) {
		return (AE_OK);
	}

	/*
	 * Two address spaces supported: Memory or IO.
	 * PCI_Config is not supported here because the GAS struct is insufficient
	 */
	switch (reg->space_id) {
	case ACPI_ADR_SPACE_SYSTEM_MEMORY:

		status = acpi_os_write_memory((acpi_physical_address) address,
					      value, width);
		break;

	case ACPI_ADR_SPACE_SYSTEM_IO:

		status = acpi_os_write_port((acpi_io_address) address,
					    value, width);
		break;

	default:
		return (AE_BAD_PARAMETER);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_IO,
			  "Wrote: %8.8X width %2d   to %8.8X%8.8X (%s)\n",
			  value, width,
			  ACPI_FORMAT_UINT64(address),
			  acpi_ut_get_region_name(reg->address_space_id)));

	return (status);
}