summaryrefslogtreecommitdiff
path: root/drivers/acpi
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/Kconfig1
-rw-r--r--drivers/acpi/acpi_processor.c182
-rw-r--r--drivers/acpi/processor_idle.c174
3 files changed, 198 insertions, 159 deletions
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 002838d23b86..cc57bab146b5 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -241,6 +241,7 @@ config ACPI_CPU_FREQ_PSS
config ACPI_PROCESSOR_CSTATE
def_bool y
+ depends on ACPI_PROCESSOR
depends on IA64 || X86
config ACPI_PROCESSOR_IDLE
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 2c4dda0787e8..5379bc3f275d 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -705,3 +705,185 @@ 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);
+
+/**
+ * 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 */
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 2ae95df2e74f..dcc289e30166 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -299,164 +299,24 @@ static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
{
- acpi_status status;
- u64 count;
- int current_count;
- int i, ret = 0;
- struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
- union acpi_object *cst;
+ int ret;
if (nocst)
return -ENODEV;
- current_count = 0;
-
- status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
- if (ACPI_FAILURE(status)) {
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\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");
- ret = -EFAULT;
- goto end;
- }
-
- count = cst->package.elements[0].integer.value;
+ ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
+ if (ret)
+ return ret;
- /* Validate number of power states. */
- if (count < 1 || count != cst->package.count - 1) {
- pr_err("count given by _CST is not valid\n");
- ret = -EFAULT;
- goto end;
- }
+ /*
+ * 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;
- /* 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;
- struct acpi_power_register *reg;
- struct acpi_processor_cx cx;
-
- 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;
-
- 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]);
- 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
- */
- if (i == 1 && cx.type != ACPI_STATE_C1)
- current_count++;
-
- cx.address = reg->address;
- cx.index = current_count + 1;
-
- 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) {
- 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.
- */
- 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 {
- snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
- cx.address);
- }
-
- 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;
-
- current_count++;
- memcpy(&(pr->power.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;
- }
- }
-
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
- current_count));
-
- /* Validate number of power states discovered */
- if (current_count < 2)
- ret = -EFAULT;
-
- end:
- kfree(buffer.pointer);
-
- return ret;
+ return 0;
}
static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
@@ -909,7 +769,6 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr)
static inline void acpi_processor_cstate_first_run_checks(void)
{
- acpi_status status;
static int first_run;
if (first_run)
@@ -921,13 +780,10 @@ static inline void acpi_processor_cstate_first_run_checks(void)
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
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-02 12:55:50 +0300