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ACPI: processor: Export acpi_processor_evaluate_cst()
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The intel_idle driver will be modified to use ACPI _CST subsequently
and it will need to call acpi_processor_evaluate_cst(), so move that
function to acpi_processor.c so that it is always present (which is
required by intel_idle) and export it to modules to allow the ACPI
processor driver (which is modular) to call it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <[email protected]>
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rafaeljw committed Dec 27, 2019
1 parent 239ed06 commit 77fb4e0
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Showing 3 changed files with 166 additions and 142 deletions.
157 changes: 157 additions & 0 deletions drivers/acpi/acpi_processor.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -729,4 +729,161 @@ bool acpi_processor_claim_cst_control(void)
return true;
}
EXPORT_SYMBOL_GPL(acpi_processor_claim_cst_control);

/**
* acpi_processor_evaluate_cst - Evaluate the processor _CST control method.
* @handle: ACPI handle of the processor object containing the _CST.
* @cpu: The numeric ID of the target CPU.
* @info: Object write the C-states information into.
*
* Extract the C-state information for the given CPU from the output of the _CST
* control method under the corresponding ACPI processor object (or processor
* device object) and populate @info with it.
*
* If any ACPI_ADR_SPACE_FIXED_HARDWARE C-states are found, invoke
* acpi_processor_ffh_cstate_probe() to verify them and update the
* cpu_cstate_entry data for @cpu.
*/
int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
struct acpi_processor_power *info)
{
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *cst;
acpi_status status;
u64 count;
int last_index = 0;
int i, ret = 0;

status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
if (ACPI_FAILURE(status)) {
acpi_handle_debug(handle, "No _CST\n");
return -ENODEV;
}

cst = buffer.pointer;

/* There must be at least 2 elements. */
if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) {
acpi_handle_warn(handle, "Invalid _CST output\n");
ret = -EFAULT;
goto end;
}

count = cst->package.elements[0].integer.value;

/* Validate the number of C-states. */
if (count < 1 || count != cst->package.count - 1) {
acpi_handle_warn(handle, "Inconsistent _CST data\n");
ret = -EFAULT;
goto end;
}

for (i = 1; i <= count; i++) {
union acpi_object *element;
union acpi_object *obj;
struct acpi_power_register *reg;
struct acpi_processor_cx cx;

/*
* If there is not enough space for all C-states, skip the
* excess ones and log a warning.
*/
if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) {
acpi_handle_warn(handle,
"No room for more idle states (limit: %d)\n",
ACPI_PROCESSOR_MAX_POWER - 1);
break;
}

memset(&cx, 0, sizeof(cx));

element = &cst->package.elements[i];
if (element->type != ACPI_TYPE_PACKAGE)
continue;

if (element->package.count != 4)
continue;

obj = &element->package.elements[0];

if (obj->type != ACPI_TYPE_BUFFER)
continue;

reg = (struct acpi_power_register *)obj->buffer.pointer;

obj = &element->package.elements[1];
if (obj->type != ACPI_TYPE_INTEGER)
continue;

cx.type = obj->integer.value;
/*
* There are known cases in which the _CST output does not
* contain C1, so if the type of the first state found is not
* C1, leave an empty slot for C1 to be filled in later.
*/
if (i == 1 && cx.type != ACPI_STATE_C1)
last_index = 1;

cx.address = reg->address;
cx.index = last_index + 1;

if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) {
/*
* In the majority of cases _CST describes C1 as
* a FIXED_HARDWARE C-state, but if the command
* line forbids using MWAIT, use CSTATE_HALT for
* C1 regardless.
*/
if (cx.type == ACPI_STATE_C1 &&
boot_option_idle_override == IDLE_NOMWAIT) {
cx.entry_method = ACPI_CSTATE_HALT;
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
} else {
cx.entry_method = ACPI_CSTATE_FFH;
}
} else if (cx.type == ACPI_STATE_C1) {
/*
* In the special case of C1, FIXED_HARDWARE can
* be handled by executing the HLT instruction.
*/
cx.entry_method = ACPI_CSTATE_HALT;
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
} else {
continue;
}
} else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
cx.entry_method = ACPI_CSTATE_SYSTEMIO;
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
cx.address);
} else {
continue;
}

if (cx.type == ACPI_STATE_C1)
cx.valid = 1;

obj = &element->package.elements[2];
if (obj->type != ACPI_TYPE_INTEGER)
continue;

cx.latency = obj->integer.value;

obj = &element->package.elements[3];
if (obj->type != ACPI_TYPE_INTEGER)
continue;

memcpy(&info->states[++last_index], &cx, sizeof(cx));
}

acpi_handle_info(handle, "Found %d idle states\n", last_index);

info->count = last_index;

end:
kfree(buffer.pointer);

return ret;
}
EXPORT_SYMBOL_GPL(acpi_processor_evaluate_cst);
#endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
142 changes: 0 additions & 142 deletions drivers/acpi/processor_idle.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -297,148 +297,6 @@ static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
return 0;
}

static int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
struct acpi_processor_power *info)
{
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *cst;
acpi_status status;
u64 count;
int last_index = 0;
int i, ret = 0;

status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
if (ACPI_FAILURE(status)) {
acpi_handle_debug(handle, "No _CST\n");
return -ENODEV;
}

cst = buffer.pointer;

/* There must be at least 2 elements. */
if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) {
acpi_handle_warn(handle, "Invalid _CST output\n");
ret = -EFAULT;
goto end;
}

count = cst->package.elements[0].integer.value;

/* Validate the number of C-states. */
if (count < 1 || count != cst->package.count - 1) {
acpi_handle_warn(handle, "Inconsistent _CST data\n");
ret = -EFAULT;
goto end;
}

for (i = 1; i <= count; i++) {
union acpi_object *element;
union acpi_object *obj;
struct acpi_power_register *reg;
struct acpi_processor_cx cx;

/*
* If there is not enough space for all C-states, skip the
* excess ones and log a warning.
*/
if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) {
acpi_handle_warn(handle,
"No room for more idle states (limit: %d)\n",
ACPI_PROCESSOR_MAX_POWER - 1);
break;
}

memset(&cx, 0, sizeof(cx));

element = &cst->package.elements[i];
if (element->type != ACPI_TYPE_PACKAGE)
continue;

if (element->package.count != 4)
continue;

obj = &element->package.elements[0];

if (obj->type != ACPI_TYPE_BUFFER)
continue;

reg = (struct acpi_power_register *)obj->buffer.pointer;

obj = &element->package.elements[1];
if (obj->type != ACPI_TYPE_INTEGER)
continue;

cx.type = obj->integer.value;
/*
* There are known cases in which the _CST output does not
* contain C1, so if the type of the first state found is not
* C1, leave an empty slot for C1 to be filled in later.
*/
if (i == 1 && cx.type != ACPI_STATE_C1)
last_index = 1;

cx.address = reg->address;
cx.index = last_index + 1;

if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) {
/*
* In the majority of cases _CST describes C1 as
* a FIXED_HARDWARE C-state, but if the command
* line forbids using MWAIT, use CSTATE_HALT for
* C1 regardless.
*/
if (cx.type == ACPI_STATE_C1 &&
boot_option_idle_override == IDLE_NOMWAIT) {
cx.entry_method = ACPI_CSTATE_HALT;
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
} else {
cx.entry_method = ACPI_CSTATE_FFH;
}
} else if (cx.type == ACPI_STATE_C1) {
/*
* In the special case of C1, FIXED_HARDWARE can
* be handled by executing the HLT instruction.
*/
cx.entry_method = ACPI_CSTATE_HALT;
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
} else {
continue;
}
} else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
cx.entry_method = ACPI_CSTATE_SYSTEMIO;
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
cx.address);
} else {
continue;
}

if (cx.type == ACPI_STATE_C1)
cx.valid = 1;

obj = &element->package.elements[2];
if (obj->type != ACPI_TYPE_INTEGER)
continue;

cx.latency = obj->integer.value;

obj = &element->package.elements[3];
if (obj->type != ACPI_TYPE_INTEGER)
continue;

memcpy(&info->states[++last_index], &cx, sizeof(cx));
}

acpi_handle_info(handle, "Found %d idle states\n", last_index);

info->count = last_index;

end:
kfree(buffer.pointer);

return ret;
}

static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
{
int ret;
Expand Down
9 changes: 9 additions & 0 deletions include/linux/acpi.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -280,10 +280,19 @@ static inline bool invalid_phys_cpuid(phys_cpuid_t phys_id)
/* Validate the processor object's proc_id */
bool acpi_duplicate_processor_id(int proc_id);
/* Processor _CTS control */
struct acpi_processor_power;

#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
bool acpi_processor_claim_cst_control(void);
int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
struct acpi_processor_power *info);
#else
static inline bool acpi_processor_claim_cst_control(void) { return false; }
static inline int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
struct acpi_processor_power *info)
{
return -ENODEV;
}
#endif

#ifdef CONFIG_ACPI_HOTPLUG_CPU
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