Subject: ACPI : Throttling control uses T-states returned by _TSS when _TSS exists
>From : Zhao Yakui <yakui.zhao@xxxxxxxxx>
If _TSS exists, throttling control will use the T-states returned by _TSS.
Otherwise the calculated T-states from FADT.duty_width are used.
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: Zhao Yakui <yakui.zhao@xxxxxxxxx>
Signed-off-by: Li Shaohua <shaohua.li@xxxxxxxxx>
---
drivers/acpi/processor_throttling.c | 42 ++++++++++++++++++++++++++++++------
1 file changed, 35 insertions(+), 7 deletions(-)
Index: linux-2.6.24-rc1/drivers/acpi/processor_throttling.c
===================================================================
--- linux-2.6.24-rc1.orig/drivers/acpi/processor_throttling.c
+++ linux-2.6.24-rc1/drivers/acpi/processor_throttling.c
@@ -131,6 +131,7 @@ static int acpi_processor_get_throttling
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
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
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(s
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(s
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:
-
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