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 throttling.
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.
Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx>
Signed-off-by: Li Shaohua <shaohua.li@xxxxxxxxx>
---
drivers/acpi/processor_throttling.c | 157 +++++++++++++++++++++++-------------
1 file changed, 103 insertions(+), 54 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
@@ -130,6 +130,7 @@ 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)) {
@@ -181,6 +182,22 @@ 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);
@@ -375,16 +392,27 @@ static int acpi_processor_get_throttling
return 0;
}
-static int acpi_read_throttling_status(struct acpi_processor_throttling
- *throttling)
+static int acpi_read_throttling_status(struct acpi_processor *pr,
+ acpi_integer *value)
{
- int value = -1;
+ u32 bit_width, bit_offset;
+ u64 ptc_mask;
+ u64 ptc_value;
+ struct acpi_processor_throttling *throttling;
+ int ret = -1;
+
+ throttling = &pr->throttling;
switch (throttling->status_register.space_id) {
case ACPI_ADR_SPACE_SYSTEM_IO:
+ 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, &value,
- (u32) throttling->status_register.bit_width *
- 8);
+ address, (u32 *)&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:
printk(KERN_ERR PREFIX
@@ -394,20 +422,30 @@ static int acpi_read_throttling_status(s
printk(KERN_ERR PREFIX "Unknown addr space %d\n",
(u32) (throttling->status_register.space_id));
}
- return value;
+ return ret;
}
-static int acpi_write_throttling_state(struct acpi_processor_throttling
- *throttling, int value)
+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:
+ 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, 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:
@@ -421,7 +459,8 @@ static int acpi_write_throttling_state(s
return ret;
}
-static int acpi_get_throttling_state(struct acpi_processor *pr, int value)
+static int acpi_get_throttling_state(struct acpi_processor *pr,
+ acpi_integer value)
{
int i;
@@ -437,22 +476,25 @@ static int acpi_get_throttling_state(str
return i;
}
-static int acpi_get_throttling_value(struct acpi_processor *pr, int state)
+static int acpi_get_throttling_value(struct acpi_processor *pr,
+ int state, acpi_integer *value)
{
- int value = -1;
+ int ret = -1;
if (state >= 0 && state <= pr->throttling.state_count) {
struct acpi_processor_tx_tss *tx =
(struct acpi_processor_tx_tss *)&(pr->throttling.
states_tss[state]);
- value = tx->control;
+ *value = tx->control;
+ ret = 0;
}
- return value;
+ return ret;
}
static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
{
int state = 0;
- u32 value = 0;
+ int ret;
+ acpi_integer value;
if (!pr)
return -EINVAL;
@@ -462,8 +504,8 @@ static int acpi_processor_get_throttling
pr->throttling.state = 0;
local_irq_disable();
- value = acpi_read_throttling_status(&pr->throttling);
- if (value >= 0) {
+ ret = acpi_read_throttling_status(pr, &value);
+ if (ret >= 0) {
state = acpi_get_throttling_state(pr, value);
pr->throttling.state = state;
}
@@ -477,6 +519,40 @@ static int acpi_processor_get_throttling
return pr->throttling.acpi_processor_get_throttling(pr);
}
+static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
+{
+ int i, step;
+
+ if (!pr->throttling.address) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
+ return -EINVAL;
+ } else if (!pr->throttling.duty_width) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
+ return -EINVAL;
+ }
+ /* TBD: Support duty_cycle values that span bit 4. */
+ else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
+ printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
+ return -EINVAL;
+ }
+
+ pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
+
+ /*
+ * Compute state values. Note that throttling displays a linear power/
+ * performance relationship (at 50% performance the CPU will consume
+ * 50% power). Values are in 1/10th of a percent to preserve accuracy.
+ */
+
+ step = (1000 / pr->throttling.state_count);
+
+ for (i = 0; i < pr->throttling.state_count; i++) {
+ pr->throttling.states[i].performance = 1000 - step * i;
+ pr->throttling.states[i].power = 1000 - step * i;
+ }
+ return 0;
+}
+
static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
int state)
{
@@ -553,7 +629,8 @@ static int acpi_processor_set_throttling
static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
int state)
{
- u32 value = 0;
+ int ret ;
+ acpi_integer value = 0;
if (!pr)
return -EINVAL;
@@ -572,9 +649,9 @@ static int acpi_processor_set_throttling
local_irq_disable();
- value = acpi_get_throttling_value(pr, state);
- if (value >= 0) {
- acpi_write_throttling_state(&pr->throttling, value);
+ ret = acpi_get_throttling_value(pr, state, &value);
+ if (ret >= 0) {
+ acpi_write_throttling_state(pr, value);
pr->throttling.state = state;
}
local_irq_enable();
@@ -590,8 +667,6 @@ int acpi_processor_set_throttling(struct
int acpi_processor_get_throttling_info(struct acpi_processor *pr)
{
int result = 0;
- int step = 0;
- int i = 0;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
@@ -610,6 +685,8 @@ int acpi_processor_get_throttling_info(s
acpi_processor_get_throttling_states(pr) ||
acpi_processor_get_platform_limit(pr))
{
+ if (acpi_processor_get_fadt_info(pr))
+ return 0;
pr->throttling.acpi_processor_get_throttling =
&acpi_processor_get_throttling_fadt;
pr->throttling.acpi_processor_set_throttling =
@@ -623,19 +700,6 @@ int acpi_processor_get_throttling_info(s
acpi_processor_get_tsd(pr);
- if (!pr->throttling.address) {
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
- return 0;
- } else if (!pr->throttling.duty_width) {
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
- return 0;
- }
- /* TBD: Support duty_cycle values that span bit 4. */
- else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
- printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
- return 0;
- }
-
/*
* PIIX4 Errata: We don't support throttling on the original PIIX4.
* This shouldn't be an issue as few (if any) mobile systems ever
@@ -647,21 +711,6 @@ int acpi_processor_get_throttling_info(s
return 0;
}
- pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
-
- /*
- * Compute state values. Note that throttling displays a linear power/
- * performance relationship (at 50% performance the CPU will consume
- * 50% power). Values are in 1/10th of a percent to preserve accuracy.
- */
-
- step = (1000 / pr->throttling.state_count);
-
- for (i = 0; i < pr->throttling.state_count; i++) {
- pr->throttling.states[i].performance = step * i;
- pr->throttling.states[i].power = step * i;
- }
-
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
pr->throttling.state_count));
-
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