* [RFC][PATCH 1/6] ACPI: processor: Export function to claim _CST control
2019-12-06 9:28 [RFC][PATCH 0/6] cpuidle: intel_idle: Use ACPI _CTS to get idle states information Rafael J. Wysocki
@ 2019-12-06 9:31 ` Rafael J. Wysocki
2019-12-06 9:32 ` [RFC][PATCH 2/6] ACPI: processor: Introduce acpi_processor_evaluate_cst() Rafael J. Wysocki
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Rafael J. Wysocki @ 2019-12-06 9:31 UTC (permalink / raw)
To: Linux PM; +Cc: LKML, Linux ACPI, Len Brown, Srinivas Pandruvada, Len Brown
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The intel_idle driver will be modified to use ACPI _CST subsequently
and it will need to notify the platform firmware of that if
acpi_gbl_FADT.cst_control is set, so add a routine for this purpose,
acpi_processor_claim_cst_control(), to acpi_processor.c (so that it
is always present which is required by intel_idle) and export it
to allow the ACPI processor driver (which is modular) to call it.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/acpi/acpi_processor.c | 25 +++++++++++++++++++++++++
drivers/acpi/processor_idle.c | 12 ++++--------
include/linux/acpi.h | 6 ++++++
3 files changed, 35 insertions(+), 8 deletions(-)
Index: linux-pm/drivers/acpi/acpi_processor.c
===================================================================
--- linux-pm.orig/drivers/acpi/acpi_processor.c
+++ linux-pm/drivers/acpi/acpi_processor.c
@@ -705,3 +705,28 @@ void __init acpi_processor_init(void)
acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
acpi_scan_add_handler(&processor_container_handler);
}
+
+#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
+/**
+ * acpi_processor_claim_cst_control - Request _CST control from the platform.
+ */
+bool acpi_processor_claim_cst_control(void)
+{
+ static bool cst_control_claimed;
+ acpi_status status;
+
+ if (!acpi_gbl_FADT.cst_control || cst_control_claimed)
+ return true;
+
+ status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
+ acpi_gbl_FADT.cst_control, 8);
+ if (ACPI_FAILURE(status)) {
+ pr_warn("ACPI: Failed to claim processor _CST control\n");
+ return false;
+ }
+
+ cst_control_claimed = true;
+ return true;
+}
+EXPORT_SYMBOL_GPL(acpi_processor_claim_cst_control);
+#endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
Index: linux-pm/drivers/acpi/processor_idle.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_idle.c
+++ linux-pm/drivers/acpi/processor_idle.c
@@ -909,7 +909,6 @@ static int acpi_processor_setup_cstates(
static inline void acpi_processor_cstate_first_run_checks(void)
{
- acpi_status status;
static int first_run;
if (first_run)
@@ -921,13 +920,10 @@ static inline void acpi_processor_cstate
max_cstate);
first_run++;
- if (acpi_gbl_FADT.cst_control && !nocst) {
- status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
- acpi_gbl_FADT.cst_control, 8);
- if (ACPI_FAILURE(status))
- ACPI_EXCEPTION((AE_INFO, status,
- "Notifying BIOS of _CST ability failed"));
- }
+ if (nocst)
+ return;
+
+ acpi_processor_claim_cst_control();
}
#else
Index: linux-pm/include/linux/acpi.h
===================================================================
--- linux-pm.orig/include/linux/acpi.h
+++ linux-pm/include/linux/acpi.h
@@ -279,6 +279,12 @@ static inline bool invalid_phys_cpuid(ph
/* Validate the processor object's proc_id */
bool acpi_duplicate_processor_id(int proc_id);
+/* Processor _CTS control */
+#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
+bool acpi_processor_claim_cst_control(void);
+#else
+static inline bool acpi_processor_claim_cst_control(void) { return false; }
+#endif
#ifdef CONFIG_ACPI_HOTPLUG_CPU
/* Arch dependent functions for cpu hotplug support */
^ permalink raw reply [flat|nested] 7+ messages in thread
* [RFC][PATCH 2/6] ACPI: processor: Introduce acpi_processor_evaluate_cst()
2019-12-06 9:28 [RFC][PATCH 0/6] cpuidle: intel_idle: Use ACPI _CTS to get idle states information Rafael J. Wysocki
2019-12-06 9:31 ` [RFC][PATCH 1/6] ACPI: processor: Export function to claim _CST control Rafael J. Wysocki
@ 2019-12-06 9:32 ` Rafael J. Wysocki
2019-12-06 9:36 ` [RFC][PATCH 3/6] ACPI: processor: Clean up acpi_processor_evaluate_cst() Rafael J. Wysocki
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Rafael J. Wysocki @ 2019-12-06 9:32 UTC (permalink / raw)
To: Linux PM; +Cc: LKML, Linux ACPI, Len Brown, Srinivas Pandruvada, Len Brown
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In order to separate the ACPI _CST evaluation from checks
specific to the ACPI processor driver, move the majority of
the acpi_processor_get_power_info_cst() function body to a new
function, acpi_processor_evaluate_cst(), that will extract
the C-states information from _CST output, and redefine
acpi_processor_get_power_info_cst() as a wrapper around it.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/acpi/processor_idle.c | 52 +++++++++++++++++++++++++-----------------
1 file changed, 32 insertions(+), 20 deletions(-)
Index: linux-pm/drivers/acpi/processor_idle.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_idle.c
+++ linux-pm/drivers/acpi/processor_idle.c
@@ -297,21 +297,17 @@ static int acpi_processor_get_power_info
return 0;
}
-static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
+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 current_count;
+ int current_count = 0;
int i, ret = 0;
- struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
- union acpi_object *cst;
-
- if (nocst)
- return -ENODEV;
-
- current_count = 0;
- status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
+ status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
if (ACPI_FAILURE(status)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
return -ENODEV;
@@ -335,9 +331,6 @@ static int acpi_processor_get_power_info
goto end;
}
- /* Tell driver that at least _CST is supported. */
- pr->flags.has_cst = 1;
-
for (i = 1; i <= count; i++) {
union acpi_object *element;
union acpi_object *obj;
@@ -383,7 +376,7 @@ static int acpi_processor_get_power_info
cx.entry_method = ACPI_CSTATE_SYSTEMIO;
if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
if (acpi_processor_ffh_cstate_probe
- (pr->id, &cx, reg) == 0) {
+ (cpu, &cx, reg) == 0) {
cx.entry_method = ACPI_CSTATE_FFH;
} else if (cx.type == ACPI_STATE_C1) {
/*
@@ -432,7 +425,7 @@ static int acpi_processor_get_power_info
continue;
current_count++;
- memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
+ memcpy(&info->states[current_count], &cx, sizeof(cx));
/*
* We support total ACPI_PROCESSOR_MAX_POWER - 1
@@ -446,12 +439,9 @@ static int acpi_processor_get_power_info
}
}
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
- current_count));
+ acpi_handle_info(handle, "Found %d idle states\n", current_count);
- /* Validate number of power states discovered */
- if (current_count < 2)
- ret = -EFAULT;
+ info->count = current_count;
end:
kfree(buffer.pointer);
@@ -459,6 +449,28 @@ static int acpi_processor_get_power_info
return ret;
}
+static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
+{
+ int ret;
+
+ if (nocst)
+ return -ENODEV;
+
+ ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
+ if (ret)
+ return ret;
+
+ /*
+ * It is expected that there will be at least 2 states, C1 and
+ * something else (C2 or C3), so fail if that is not the case.
+ */
+ if (pr->power.count < 2)
+ return -EFAULT;
+
+ pr->flags.has_cst = 1;
+ return 0;
+}
+
static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
struct acpi_processor_cx *cx)
{
^ permalink raw reply [flat|nested] 7+ messages in thread
* [RFC][PATCH 3/6] ACPI: processor: Clean up acpi_processor_evaluate_cst()
2019-12-06 9:28 [RFC][PATCH 0/6] cpuidle: intel_idle: Use ACPI _CTS to get idle states information Rafael J. Wysocki
2019-12-06 9:31 ` [RFC][PATCH 1/6] ACPI: processor: Export function to claim _CST control Rafael J. Wysocki
2019-12-06 9:32 ` [RFC][PATCH 2/6] ACPI: processor: Introduce acpi_processor_evaluate_cst() Rafael J. Wysocki
@ 2019-12-06 9:36 ` Rafael J. Wysocki
2019-12-06 9:37 ` [RFC][PATCH 4/6] ACPI: processor: Export acpi_processor_evaluate_cst() Rafael J. Wysocki
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Rafael J. Wysocki @ 2019-12-06 9:36 UTC (permalink / raw)
To: Linux PM; +Cc: LKML, Linux ACPI, Len Brown, Srinivas Pandruvada, Len Brown
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Clean up acpi_processor_evaluate_cst() in multiple ways:
* Rename current_count to last_index which matches the purpose of
the variable better.
* Consistently use acpi_handle_*() for printing messages and make
the messages cleaner.
* Drop redundant parens and braces.
* Rewrite and clarify comments.
* Rearrange checks and drop the redundant ones.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/acpi/processor_idle.c | 114 +++++++++++++++++++-----------------------
1 file changed, 52 insertions(+), 62 deletions(-)
Index: linux-pm/drivers/acpi/processor_idle.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_idle.c
+++ linux-pm/drivers/acpi/processor_idle.c
@@ -304,29 +304,29 @@ static int acpi_processor_evaluate_cst(a
union acpi_object *cst;
acpi_status status;
u64 count;
- int current_count = 0;
+ int last_index = 0;
int i, ret = 0;
status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
if (ACPI_FAILURE(status)) {
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
+ 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) {
- pr_err("not enough elements in _CST\n");
+ /* 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 number of power states. */
+ /* Validate the number of C-states. */
if (count < 1 || count != cst->package.count - 1) {
- pr_err("count given by _CST is not valid\n");
+ acpi_handle_warn(handle, "Inconsistent _CST data\n");
ret = -EFAULT;
goto end;
}
@@ -337,111 +337,101 @@ static int acpi_processor_evaluate_cst(a
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]);
+ element = &cst->package.elements[i];
if (element->type != ACPI_TYPE_PACKAGE)
continue;
if (element->package.count != 4)
continue;
- obj = &(element->package.elements[0]);
+ obj = &element->package.elements[0];
if (obj->type != ACPI_TYPE_BUFFER)
continue;
reg = (struct acpi_power_register *)obj->buffer.pointer;
- if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
- (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
- continue;
-
- /* There should be an easy way to extract an integer... */
- obj = &(element->package.elements[1]);
+ obj = &element->package.elements[1];
if (obj->type != ACPI_TYPE_INTEGER)
continue;
cx.type = obj->integer.value;
/*
- * Some buggy BIOSes won't list C1 in _CST -
- * Let acpi_processor_get_power_info_default() handle them later
+ * 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)
- current_count++;
+ last_index = 1;
cx.address = reg->address;
- cx.index = current_count + 1;
+ cx.index = last_index + 1;
- cx.entry_method = ACPI_CSTATE_SYSTEMIO;
if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
- if (acpi_processor_ffh_cstate_probe
- (cpu, &cx, reg) == 0) {
- cx.entry_method = ACPI_CSTATE_FFH;
+ 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) {
/*
- * C1 is a special case where FIXED_HARDWARE
- * can be handled in non-MWAIT way as well.
- * In that case, save this _CST entry info.
- * Otherwise, ignore this info and continue.
+ * 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;
}
- if (cx.type == ACPI_STATE_C1 &&
- (boot_option_idle_override == IDLE_NOMWAIT)) {
- /*
- * In most cases the C1 space_id obtained from
- * _CST object is FIXED_HARDWARE access mode.
- * But when the option of idle=halt is added,
- * the entry_method type should be changed from
- * CSTATE_FFH to CSTATE_HALT.
- * When the option of idle=nomwait is added,
- * the C1 entry_method type should be
- * CSTATE_HALT.
- */
- cx.entry_method = ACPI_CSTATE_HALT;
- snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
- }
- } else {
+ } 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) {
+ if (cx.type == ACPI_STATE_C1)
cx.valid = 1;
- }
- obj = &(element->package.elements[2]);
+ obj = &element->package.elements[2];
if (obj->type != ACPI_TYPE_INTEGER)
continue;
cx.latency = obj->integer.value;
- obj = &(element->package.elements[3]);
+ obj = &element->package.elements[3];
if (obj->type != ACPI_TYPE_INTEGER)
continue;
- current_count++;
- memcpy(&info->states[current_count], &cx, sizeof(cx));
-
- /*
- * We support total ACPI_PROCESSOR_MAX_POWER - 1
- * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
- */
- if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
- pr_warn("Limiting number of power states to max (%d)\n",
- ACPI_PROCESSOR_MAX_POWER);
- pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
- break;
- }
+ memcpy(&info->states[++last_index], &cx, sizeof(cx));
}
- acpi_handle_info(handle, "Found %d idle states\n", current_count);
+ acpi_handle_info(handle, "Found %d idle states\n", last_index);
- info->count = current_count;
+ info->count = last_index;
end:
kfree(buffer.pointer);
^ permalink raw reply [flat|nested] 7+ messages in thread
* [RFC][PATCH 4/6] ACPI: processor: Export acpi_processor_evaluate_cst()
2019-12-06 9:28 [RFC][PATCH 0/6] cpuidle: intel_idle: Use ACPI _CTS to get idle states information Rafael J. Wysocki
` (2 preceding siblings ...)
2019-12-06 9:36 ` [RFC][PATCH 3/6] ACPI: processor: Clean up acpi_processor_evaluate_cst() Rafael J. Wysocki
@ 2019-12-06 9:37 ` Rafael J. Wysocki
2019-12-06 9:46 ` [RFC][PATCH 5/6] intel_idle: Refactor intel_idle_cpuidle_driver_init() Rafael J. Wysocki
2019-12-06 9:46 ` [RFC][PATCH 6/6] intel_idle: Use ACPI _CST for processor models without C-state tables Rafael J. Wysocki
5 siblings, 0 replies; 7+ messages in thread
From: Rafael J. Wysocki @ 2019-12-06 9:37 UTC (permalink / raw)
To: Linux PM; +Cc: LKML, Linux ACPI, Len Brown, Srinivas Pandruvada, Len Brown
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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 <rafael.j.wysocki@intel.com>
---
drivers/acpi/acpi_processor.c | 154 ++++++++++++++++++++++++++++++++++++++++++
drivers/acpi/processor_idle.c | 139 -------------------------------------
include/linux/acpi.h | 9 ++
3 files changed, 163 insertions(+), 139 deletions(-)
Index: linux-pm/drivers/acpi/acpi_processor.c
===================================================================
--- linux-pm.orig/drivers/acpi/acpi_processor.c
+++ linux-pm/drivers/acpi/acpi_processor.c
@@ -729,4 +729,161 @@ bool acpi_processor_claim_cst_control(vo
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 */
Index: linux-pm/include/linux/acpi.h
===================================================================
--- linux-pm.orig/include/linux/acpi.h
+++ linux-pm/include/linux/acpi.h
@@ -280,10 +280,19 @@ static inline bool invalid_phys_cpuid(ph
/* 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
Index: linux-pm/drivers/acpi/processor_idle.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_idle.c
+++ linux-pm/drivers/acpi/processor_idle.c
@@ -297,148 +297,6 @@ static int acpi_processor_get_power_info
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;
^ permalink raw reply [flat|nested] 7+ messages in thread
* [RFC][PATCH 5/6] intel_idle: Refactor intel_idle_cpuidle_driver_init()
2019-12-06 9:28 [RFC][PATCH 0/6] cpuidle: intel_idle: Use ACPI _CTS to get idle states information Rafael J. Wysocki
` (3 preceding siblings ...)
2019-12-06 9:37 ` [RFC][PATCH 4/6] ACPI: processor: Export acpi_processor_evaluate_cst() Rafael J. Wysocki
@ 2019-12-06 9:46 ` Rafael J. Wysocki
2019-12-06 9:46 ` [RFC][PATCH 6/6] intel_idle: Use ACPI _CST for processor models without C-state tables Rafael J. Wysocki
5 siblings, 0 replies; 7+ messages in thread
From: Rafael J. Wysocki @ 2019-12-06 9:46 UTC (permalink / raw)
To: Linux PM; +Cc: LKML, Linux ACPI, Len Brown, Srinivas Pandruvada, Len Brown
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Move the C-state verification and checks from
intel_idle_cpuidle_driver_init() to a separate function,
intel_idle_verify_cstate(), and make the former call it after
checking the CPUIDLE_FLAG_UNUSABLE state flag.
Also combine the drv->states[] updates with the incrementation of
drv->state_count.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/idle/intel_idle.c | 49 +++++++++++++++++++++++-----------------------
1 file changed, 25 insertions(+), 24 deletions(-)
Index: linux-pm/drivers/idle/intel_idle.c
===================================================================
--- linux-pm.orig/drivers/idle/intel_idle.c
+++ linux-pm/drivers/idle/intel_idle.c
@@ -944,6 +944,22 @@ static void intel_idle_s2idle(struct cpu
mwait_idle_with_hints(eax, ecx);
}
+static bool intel_idle_verify_cstate(unsigned int mwait_hint)
+{
+ unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1;
+ unsigned int num_substates = (mwait_substates >> mwait_cstate * 4) &
+ MWAIT_SUBSTATE_MASK;
+
+ /* Ignore the C-state if there are NO sub-states in CPUID for it. */
+ if (num_substates == 0)
+ return false;
+
+ if (mwait_cstate > 2 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
+ mark_tsc_unstable("TSC halts in idle states deeper than C2");
+
+ return true;
+}
+
static void __setup_broadcast_timer(bool on)
{
if (on)
@@ -1332,10 +1348,10 @@ static void __init intel_idle_cpuidle_dr
drv->state_count = 1;
for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
- int num_substates, mwait_hint, mwait_cstate;
+ unsigned int mwait_hint;
- if ((cpuidle_state_table[cstate].enter == NULL) &&
- (cpuidle_state_table[cstate].enter_s2idle == NULL))
+ if (!cpuidle_state_table[cstate].enter &&
+ !cpuidle_state_table[cstate].enter_s2idle)
break;
if (cstate + 1 > max_cstate) {
@@ -1343,34 +1359,19 @@ static void __init intel_idle_cpuidle_dr
break;
}
- mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
- mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);
-
- /* number of sub-states for this state in CPUID.MWAIT */
- num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))
- & MWAIT_SUBSTATE_MASK;
-
- /* if NO sub-states for this state in CPUID, skip it */
- if (num_substates == 0)
- continue;
-
- /* if state marked as disabled, skip it */
+ /* If marked as unusable, skip this state. */
if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
pr_debug("state %s is disabled\n",
cpuidle_state_table[cstate].name);
continue;
}
+ mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
+ if (!intel_idle_verify_cstate(mwait_hint))
+ continue;
- if (((mwait_cstate + 1) > 2) &&
- !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
- mark_tsc_unstable("TSC halts in idle"
- " states deeper than C2");
-
- drv->states[drv->state_count] = /* structure copy */
- cpuidle_state_table[cstate];
-
- drv->state_count += 1;
+ /* Structure copy. */
+ drv->states[drv->state_count++] = cpuidle_state_table[cstate];
}
if (icpu->byt_auto_demotion_disable_flag) {
^ permalink raw reply [flat|nested] 7+ messages in thread
* [RFC][PATCH 6/6] intel_idle: Use ACPI _CST for processor models without C-state tables
2019-12-06 9:28 [RFC][PATCH 0/6] cpuidle: intel_idle: Use ACPI _CTS to get idle states information Rafael J. Wysocki
` (4 preceding siblings ...)
2019-12-06 9:46 ` [RFC][PATCH 5/6] intel_idle: Refactor intel_idle_cpuidle_driver_init() Rafael J. Wysocki
@ 2019-12-06 9:46 ` Rafael J. Wysocki
5 siblings, 0 replies; 7+ messages in thread
From: Rafael J. Wysocki @ 2019-12-06 9:46 UTC (permalink / raw)
To: Linux PM; +Cc: LKML, Linux ACPI, Len Brown, Srinivas Pandruvada, Len Brown
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Modify the intel_idle driver to get the C-states information from ACPI
_CST if the processor model is not recognized by it.
The processor is still required to support MWAIT and the information
from ACPI _CST will only be used if all of the C-states listed by
_CST are of the ACPI_CSTATE_FFH type (which means that they are
expected to be entered via MWAIT).
Moreover, the driver assumes that the _CST information is the same
for all CPUs in the system, so it is sufficient to evaluate _CST for
one of them and extract the common list of C-states from there.
Also _CST is evaluated once at the system initialization time and
the driver does not respond to _CST change notifications (the plan
is to change that in the future).
[The next step will be to combine the _CST data with the driver's
own static tables of C-states for some processors n order to allow
of more robustness.]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/idle/intel_idle.c | 181 ++++++++++++++++++++++++++++++++++++++--------
1 file changed, 153 insertions(+), 28 deletions(-)
Index: linux-pm/drivers/idle/intel_idle.c
===================================================================
--- linux-pm.orig/drivers/idle/intel_idle.c
+++ linux-pm/drivers/idle/intel_idle.c
@@ -41,6 +41,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/cpuidle.h>
#include <linux/tick.h>
@@ -1111,6 +1112,120 @@ static const struct x86_cpu_id intel_idl
{}
};
+#define INTEL_CPU_FAM6_MWAIT \
+ { X86_VENDOR_INTEL, 6, X86_MODEL_ANY, X86_FEATURE_MWAIT, 0 }
+
+static const struct x86_cpu_id intel_mwait_ids[] __initconst = {
+ INTEL_CPU_FAM6_MWAIT,
+ {}
+};
+
+static bool intel_idle_max_cstate_reached(int cstate)
+{
+ if (cstate + 1 > max_cstate) {
+ pr_info("max_cstate %d reached\n", max_cstate);
+ return true;
+ }
+ return false;
+}
+
+#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
+#include <acpi/processor.h>
+
+static struct acpi_processor_power acpi_state_table;
+
+/**
+ * intel_idle_cst_usable - Check if the _CST information can be used.
+ *
+ * Check if all of the C-states listed by _CST in the max_cstate range are
+ * ACPI_CSTATE_FFH, which means that they should be entered via MWAIT.
+ */
+static bool intel_idle_cst_usable(void)
+{
+ int cstate, limit;
+
+ limit = min_t(int, min_t(int, CPUIDLE_STATE_MAX, max_cstate + 1),
+ acpi_state_table.count);
+
+ for (cstate = 1; cstate < limit; cstate++) {
+ struct acpi_processor_cx *cx = &acpi_state_table.states[cstate];
+
+ if (cx->entry_method != ACPI_CSTATE_FFH)
+ return false;
+ }
+
+ return true;
+}
+
+static bool intel_idle_acpi_cst_extract(void)
+{
+ unsigned int cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct acpi_processor *pr = per_cpu(processors, cpu);
+
+ if (!pr)
+ continue;
+
+ if (acpi_processor_evaluate_cst(pr->handle, cpu, &acpi_state_table))
+ continue;
+
+ acpi_state_table.count++;
+
+ if (!intel_idle_cst_usable())
+ continue;
+
+ if (!acpi_processor_claim_cst_control()) {
+ acpi_state_table.count = 0;
+ return false;
+ }
+
+ return true;
+ }
+
+ pr_debug("ACPI _CST not found or not usable\n");
+ return false;
+}
+
+static void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv)
+{
+ int cstate, limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
+
+ /*
+ * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
+ * the interesting states are ACPI_CSTATE_FFH.
+ */
+ for (cstate = 1; cstate < limit; cstate++) {
+ struct acpi_processor_cx *cx;
+ struct cpuidle_state *state;
+
+ if (intel_idle_max_cstate_reached(cstate))
+ break;
+
+ cx = &acpi_state_table.states[cstate];
+
+ state = &drv->states[drv->state_count++];
+
+ snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", cstate);
+ strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
+ state->exit_latency = cx->latency;
+ state->target_residency = cx->latency;
+ if (cx->type > ACPI_STATE_C1)
+ state->target_residency += 2 * cx->latency;
+
+ state->flags = MWAIT2flg(cx->address);
+ if (cx->type > ACPI_STATE_C2)
+ state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
+
+ state->enter = intel_idle;
+ state->enter_s2idle = intel_idle_s2idle;
+ }
+}
+#else /* !CONFIG_ACPI_PROCESSOR_CSTATE */
+static inline bool intel_idle_acpi_cst_extract(void) { return false; }
+static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { }
+#endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */
+
/*
* intel_idle_probe()
*/
@@ -1125,17 +1240,15 @@ static int __init intel_idle_probe(void)
}
id = x86_match_cpu(intel_idle_ids);
- if (!id) {
- if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
- boot_cpu_data.x86 == 6)
- pr_debug("does not run on family %d model %d\n",
- boot_cpu_data.x86, boot_cpu_data.x86_model);
- return -ENODEV;
- }
-
- if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
- pr_debug("Please enable MWAIT in BIOS SETUP\n");
- return -ENODEV;
+ if (id) {
+ if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
+ pr_debug("Please enable MWAIT in BIOS SETUP\n");
+ return -ENODEV;
+ }
+ } else {
+ id = x86_match_cpu(intel_mwait_ids);
+ if (!id)
+ return -ENODEV;
}
if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
@@ -1151,7 +1264,10 @@ static int __init intel_idle_probe(void)
pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
icpu = (const struct idle_cpu *)id->driver_data;
- cpuidle_state_table = icpu->state_table;
+ if (icpu)
+ cpuidle_state_table = icpu->state_table;
+ else if (!intel_idle_acpi_cst_extract())
+ return -ENODEV;
pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
boot_cpu_data.x86_model);
@@ -1333,31 +1449,19 @@ static void intel_idle_state_table_updat
}
}
-/*
- * intel_idle_cpuidle_driver_init()
- * allocate, initialize cpuidle_states
- */
-static void __init intel_idle_cpuidle_driver_init(void)
+static void intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
{
int cstate;
- struct cpuidle_driver *drv = &intel_idle_driver;
-
- intel_idle_state_table_update();
-
- cpuidle_poll_state_init(drv);
- drv->state_count = 1;
for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
unsigned int mwait_hint;
- if (!cpuidle_state_table[cstate].enter &&
- !cpuidle_state_table[cstate].enter_s2idle)
+ if (intel_idle_max_cstate_reached(cstate))
break;
- if (cstate + 1 > max_cstate) {
- pr_info("max_cstate %d reached\n", max_cstate);
+ if (!cpuidle_state_table[cstate].enter &&
+ !cpuidle_state_table[cstate].enter_s2idle)
break;
- }
/* If marked as unusable, skip this state. */
if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
@@ -1380,6 +1484,24 @@ static void __init intel_idle_cpuidle_dr
}
}
+/*
+ * intel_idle_cpuidle_driver_init()
+ * allocate, initialize cpuidle_states
+ */
+static void __init intel_idle_cpuidle_driver_init(void)
+{
+ struct cpuidle_driver *drv = &intel_idle_driver;
+
+ intel_idle_state_table_update();
+
+ cpuidle_poll_state_init(drv);
+ drv->state_count = 1;
+
+ if (icpu)
+ intel_idle_init_cstates_icpu(drv);
+ else
+ intel_idle_init_cstates_acpi(drv);
+}
/*
* intel_idle_cpu_init()
@@ -1398,6 +1520,9 @@ static int intel_idle_cpu_init(unsigned
return -EIO;
}
+ if (!icpu)
+ return 0;
+
if (icpu->auto_demotion_disable_flags)
auto_demotion_disable();
^ permalink raw reply [flat|nested] 7+ messages in thread