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Commit 9bcb2721 authored by Zhao Yakui's avatar Zhao Yakui Committed by Len Brown
Browse files

ACPI: Use _TSS for throttling control, when present. Add error checks. 



_TSS was erroneously ignored, in favor of the FADT.

When TSS is used, the access width is included in the PTC control/status
register.  So it is unnecessary that the access bit width is multiplied by 8.
At the same time the bit_offset should be considered for system I/O Access.

It should be checked the bit_width and bit_offset of PTC regsiter in order to
avoid the failure of system I/O access. It means that bit_width plus
bit_offset can't be greater than 32.

Signed-off-by: default avatarZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: default avatarLi Shaohua <shaohua.li@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 0753f6e0

drivers/acpi/processor_throttling.c

+35 −7
Original line number Diff line number Diff line
@@ -131,6 +131,7 @@ static int acpi_processor_get_throttling_control(struct acpi_processor *pr) 
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	union acpi_object *ptc = NULL;

	union acpi_object obj = { 0 };

	struct acpi_processor_throttling *throttling;



	status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);

	if (ACPI_FAILURE(status)) {
@@ -182,6 +183,22 @@ static int acpi_processor_get_throttling_control(struct acpi_processor *pr) 
	memcpy(&pr->throttling.status_register, obj.buffer.pointer,

	       sizeof(struct acpi_ptc_register));



	throttling = &pr->throttling;



	if ((throttling->control_register.bit_width +

		throttling->control_register.bit_offset) > 32) {

		printk(KERN_ERR PREFIX "Invalid _PTC control register\n");

		result = -EFAULT;

		goto end;

	}



	if ((throttling->status_register.bit_width +

		throttling->status_register.bit_offset) > 32) {

		printk(KERN_ERR PREFIX "Invalid _PTC status register\n");

		result = -EFAULT;

		goto end;

	}



      end:

	kfree(buffer.pointer);
@@ -379,7 +396,9 @@ static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr) 
static int acpi_read_throttling_status(struct acpi_processor *pr,

					acpi_integer *value)

{

	u32 bit_width, bit_offset;

	u64 ptc_value;

	u64 ptc_mask;

	struct acpi_processor_throttling *throttling;

	int ret = -1;
@@ -387,11 +406,14 @@ static int acpi_read_throttling_status(struct acpi_processor *pr, 
	switch (throttling->status_register.space_id) {

	case ACPI_ADR_SPACE_SYSTEM_IO:

		ptc_value = 0;

		bit_width = throttling->status_register.bit_width;

		bit_offset = throttling->status_register.bit_offset;



		acpi_os_read_port((acpi_io_address) throttling->status_register.

				  address, (u32 *) &ptc_value,

				  (u32) throttling->status_register.bit_width *

				  8);

		*value = (acpi_integer) ptc_value;

				  (u32) (bit_width + bit_offset));

		ptc_mask = (1 << bit_width) - 1;

		*value = (acpi_integer) ((ptc_value >> bit_offset) & ptc_mask);

		ret = 0;

		break;

	case ACPI_ADR_SPACE_FIXED_HARDWARE:
@@ -408,18 +430,24 @@ static int acpi_read_throttling_status(struct acpi_processor *pr, 
static int acpi_write_throttling_state(struct acpi_processor *pr,

				acpi_integer value)

{

	u32 bit_width, bit_offset;

	u64 ptc_value;

	u64 ptc_mask;

	struct acpi_processor_throttling *throttling;

	int ret = -1;



	throttling = &pr->throttling;

	switch (throttling->control_register.space_id) {

	case ACPI_ADR_SPACE_SYSTEM_IO:

		ptc_value = value;

		bit_width = throttling->control_register.bit_width;

		bit_offset = throttling->control_register.bit_offset;

		ptc_mask = (1 << bit_width) - 1;

		ptc_value = value & ptc_mask;



		acpi_os_write_port((acpi_io_address) throttling->

				   control_register.address, (u32) ptc_value,

				   (u32) throttling->control_register.

				   bit_width * 8);

					control_register.address,

					(u32) (ptc_value << bit_offset),

					(u32) (bit_width + bit_offset));

		ret = 0;

		break;

	case ACPI_ADR_SPACE_FIXED_HARDWARE: