Subject: ACPI : Add T-state coordination when updating T-state
>From : Zhao Yakui <yakui.zhao@xxxxxxxxx>
Accordint to ACPI spec, the _TSD object provides T-state control cross
logical processor dependency information to OSPM. So the t-state
coordination should be considered when T-state for one cpu is changed.
After the _TSD data for all cpus are obtained, OSPM will set up
the T-state coordination. When T-state for one cpu is changed, OSPM
should consider the coordination and update the T-state for other
affected CPUs.
Of course if the _TSD doesn't exist or _TSD data is uncorrect , it is
assumed that there is no T-state coordination and T-state is changed
independently.
Now there is no proper solution to update T-state coordination after
one cpu is hotplugged. So this patch can't support hotplugged cpu very well.
Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx>
---
drivers/acpi/processor_core.c | 2
drivers/acpi/processor_throttling.c | 313 +++++++++++++++++++++++++++++++++++-
include/acpi/processor.h | 5
3 files changed, 314 insertions(+), 6 deletions(-)
Index: linux-2.6.24-rc7/include/acpi/processor.h
===================================================================
--- linux-2.6.24-rc7.orig/include/acpi/processor.h
+++ linux-2.6.24-rc7/include/acpi/processor.h
@@ -168,7 +168,6 @@ struct acpi_processor_throttling {
unsigned int state_count;
struct acpi_processor_tx_tss *states_tss;
struct acpi_tsd_package domain_info;
- cpumask_t shared_cpu_map;
int (*acpi_processor_get_throttling) (struct acpi_processor * pr);
int (*acpi_processor_set_throttling) (struct acpi_processor * pr,
int state);
@@ -176,6 +175,9 @@ struct acpi_processor_throttling {
u32 address;
u8 duty_offset;
u8 duty_width;
+ u8 tsd_valid_flag;
+ cpumask_t shared_cpu_map;
+ unsigned int shared_type;
struct acpi_processor_tx states[ACPI_PROCESSOR_MAX_THROTTLING];
};
@@ -316,6 +318,7 @@ static inline int acpi_processor_ppc_has
int acpi_processor_get_throttling_info(struct acpi_processor *pr);
extern int acpi_processor_set_throttling(struct acpi_processor *pr, int state);
extern struct file_operations acpi_processor_throttling_fops;
+extern void acpi_processor_throttling_init(void);
/* in processor_idle.c */
int acpi_processor_power_init(struct acpi_processor *pr,
Index: linux-2.6.24-rc7/drivers/acpi/processor_throttling.c
===================================================================
--- linux-2.6.24-rc7.orig/drivers/acpi/processor_throttling.c
+++ linux-2.6.24-rc7/drivers/acpi/processor_throttling.c
@@ -45,9 +45,222 @@
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_throttling");
+struct throttling_tstate {
+ unsigned int cpu; /* cpu nr */
+ int target_state; /* target T-state */
+};
+
+#define THROTTLING_PRECHANGE (1)
+#define THROTTLING_POSTCHANGE (2)
+
+
+
static int acpi_processor_get_throttling(struct acpi_processor *pr);
int acpi_processor_set_throttling(struct acpi_processor *pr, int state);
+static int acpi_processor_throttling_notifier(unsigned long event, void *data)
+{
+ struct throttling_tstate *p_tstate = data;
+ struct acpi_processor *pr;
+ unsigned int cpu ;
+ int target_state;
+ struct acpi_processor_limit *p_limit;
+ struct acpi_processor_throttling *p_throttling;
+
+ cpu = p_tstate->cpu;
+ pr = processors[cpu];
+ target_state = p_tstate->target_state;
+ p_throttling = &(pr->throttling);
+ switch (event) {
+ case THROTTLING_PRECHANGE:
+ /*
+ * Prechange event is used to choose One T-state,
+ * which meets the limits of thermal, user and
+ * _TPC.
+ */
+ p_limit = &pr->limit;
+ if (p_limit->thermal.tx > target_state)
+ target_state = p_limit->thermal.tx;
+ if (p_limit->user.tx > target_state)
+ target_state = p_limit->user.tx;
+ if (pr->throttling_platform_limit > target_state)
+ target_state = pr->throttling_platform_limit;
+ if (target_state >= p_throttling->state_count) {
+ printk(KERN_WARNING
+ "Exceed the limit of T-state \n");
+ target_state = p_throttling->state_count - 1;
+ }
+ p_tstate->target_state = target_state;
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
+ "target T-state of CPU %d is T%d\n",
+ cpu, target_state));
+ break;
+ case THROTTLING_POSTCHANGE:
+ /*
+ * Postchange event is only used to update the
+ * T-state flag of acpi_processor_throttling.
+ */
+ p_throttling->state = target_state;
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
+ "CPU %d is switched to T%d\n",
+ cpu, target_state));
+ break;
+ default:
+ printk(KERN_WARNING
+ "Unsupported Throttling notifier event\n");
+ break;
+ }
+
+ return 0;
+}
+
+static int acpi_processor_update_tsd_coord(void)
+{
+ int count, count_target;
+ int retval = 0;
+ unsigned int i, j;
+ cpumask_t covered_cpus;
+ struct acpi_processor *pr, *match_pr;
+ struct acpi_tsd_package *pdomain, *match_pdomain;
+ struct acpi_processor_throttling *pthrottling, *match_pthrottling;
+
+ /*
+ * Now that we have _TSD data from all CPUs, lets setup T-state
+ * coordination between all CPUs.
+ */
+ for_each_possible_cpu(i) {
+ pr = processors[i];
+ if (!pr)
+ continue;
+
+ /* Basic validity check for domain info */
+ pthrottling = &(pr->throttling);
+
+ /*
+ * If tsd package for one cpu is invalid, the coordination
+ * between all CPUs are thought as invalid.
+ * Maybe it is ugly.
+ */
+ if (!pthrottling->tsd_valid_flag) {
+ retval = -EINVAL;
+ break;
+ }
+ }
+ if (retval)
+ goto err_ret;
+
+ cpus_clear(covered_cpus);
+ for_each_possible_cpu(i) {
+ pr = processors[i];
+ if (!pr)
+ continue;
+
+ if (cpu_isset(i, covered_cpus))
+ continue;
+ pthrottling = &pr->throttling;
+
+ pdomain = &(pthrottling->domain_info);
+ cpu_set(i, pthrottling->shared_cpu_map);
+ cpu_set(i, covered_cpus);
+ /*
+ * If the number of processor in the TSD domain is 1, it is
+ * unnecessary to parse the coordination for this CPU.
+ */
+ if (pdomain->num_processors <= 1)
+ continue;
+
+ /* Validate the Domain info */
+ count_target = pdomain->num_processors;
+ count = 1;
+
+ for_each_possible_cpu(j) {
+ if (i == j)
+ continue;
+
+ match_pr = processors[j];
+ if (!match_pr)
+ continue;
+
+ match_pthrottling = &(match_pr->throttling);
+ match_pdomain = &(match_pthrottling->domain_info);
+ if (match_pdomain->domain != pdomain->domain)
+ continue;
+
+ /* Here i and j are in the same domain.
+ * If two TSD packages have the same domain, they
+ * should have the same num_porcessors and
+ * coordination type. Otherwise it will be regarded
+ * as illegal.
+ */
+ if (match_pdomain->num_processors != count_target) {
+ retval = -EINVAL;
+ goto err_ret;
+ }
+
+ if (pdomain->coord_type != match_pdomain->coord_type) {
+ retval = -EINVAL;
+ goto err_ret;
+ }
+
+ cpu_set(j, covered_cpus);
+ cpu_set(j, pthrottling->shared_cpu_map);
+ count++;
+ }
+ for_each_possible_cpu(j) {
+ if (i == j)
+ continue;
+
+ match_pr = processors[j];
+ if (!match_pr)
+ continue;
+
+ match_pthrottling = &(match_pr->throttling);
+ match_pdomain = &(match_pthrottling->domain_info);
+ if (match_pdomain->domain != pdomain->domain)
+ continue;
+
+ /*
+ * If some CPUS have the same domain, they
+ * will have the same shared_cpu_map.
+ */
+ match_pthrottling->shared_cpu_map =
+ pthrottling->shared_cpu_map;
+ }
+ }
+
+err_ret:
+ for_each_possible_cpu(i) {
+ pr = processors[i];
+ if (!pr)
+ continue;
+
+ /*
+ * Assume no coordination on any error parsing domain info.
+ * The coordination type will be forced as SW_ALL.
+ */
+ if (retval) {
+ pthrottling = &(pr->throttling);
+ cpus_clear(pthrottling->shared_cpu_map);
+ cpu_set(i, pthrottling->shared_cpu_map);
+ pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
+ }
+ }
+
+ return retval;
+}
+
+/*
+ * Update the T-state coordination after the _TSD
+ * data for all cpus is obtained.
+ */
+void acpi_processor_throttling_init(void)
+{
+ if (acpi_processor_update_tsd_coord())
+ ACPI_WARNING((AE_INFO, "Assume no T-state coordination"));
+
+ return;
+}
+
/*
* _TPC - Throttling Present Capabilities
*/
@@ -293,6 +506,10 @@ static int acpi_processor_get_tsd(struct
struct acpi_buffer state = { 0, NULL };
union acpi_object *tsd = NULL;
struct acpi_tsd_package *pdomain;
+ struct acpi_processor_throttling *pthrottling;
+
+ pthrottling = &pr->throttling;
+ pthrottling->tsd_valid_flag = 0;
status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
if (ACPI_FAILURE(status)) {
@@ -340,6 +557,22 @@ static int acpi_processor_get_tsd(struct
goto end;
}
+ pthrottling = &pr->throttling;
+ pthrottling->tsd_valid_flag = 1;
+ pthrottling->shared_type = pdomain->coord_type;
+ cpu_set(pr->id, pthrottling->shared_cpu_map);
+ /*
+ * If the coordination type is not defined in ACPI spec,
+ * the tsd_valid_flag will be clear and coordination type
+ * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
+ */
+ if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
+ pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
+ pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
+ pthrottling->tsd_valid_flag = 0;
+ pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
+ }
+
end:
kfree(buffer.pointer);
return result;
@@ -743,12 +976,72 @@ int acpi_processor_set_throttling(struct
{
cpumask_t saved_mask;
int ret;
+ unsigned int i;
+ struct acpi_processor *match_pr;
+ struct acpi_processor_throttling *p_throttling;
+ struct throttling_tstate t_state;
+ cpumask_t online_throttling_cpus;
+
+ if (!pr)
+ return -EINVAL;
+
+ if ((state < 0) || (state > (pr->throttling.state_count - 1)))
+ return -EINVAL;
+
+ if (!pr->flags.throttling)
+ return -ENODEV;
+
+ saved_mask = current->cpus_allowed;
+ t_state.target_state = state;
+ p_throttling = &(pr->throttling);
+ cpus_and(online_throttling_cpus, cpu_online_map,
+ p_throttling->shared_cpu_map);
/*
- * Migrate task to the cpu pointed by pr.
+ * The throttling notifier will be called for every
+ * affected cpu in order to get one proper T-state.
+ * The notifier event is THROTTLING_PRECHANGE.
*/
- saved_mask = current->cpus_allowed;
- set_cpus_allowed(current, cpumask_of_cpu(pr->id));
- ret = pr->throttling.acpi_processor_set_throttling(pr, state);
+ for_each_cpu_mask(i, online_throttling_cpus) {
+ t_state.cpu = i;
+ acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
+ &t_state);
+ }
+ /*
+ * The function of acpi_processor_set_throttling will be called
+ * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
+ * it is necessary to call it for every affected cpu. Otherwise
+ * it can be called only for the cpu pointed by pr.
+ */
+ if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
+ set_cpus_allowed(current, cpumask_of_cpu(pr->id));
+ ret = p_throttling->acpi_processor_set_throttling(pr,
+ t_state.target_state);
+ } else {
+ /*
+ * When the T-state coordination is SW_ALL or HW_ALL,
+ * it is necessary to set T-state for every affected
+ * cpus.
+ */
+ for_each_cpu_mask(i, online_throttling_cpus) {
+ match_pr = processors[i];
+ t_state.cpu = i;
+ set_cpus_allowed(current, cpumask_of_cpu(i));
+ ret = match_pr->throttling.
+ acpi_processor_set_throttling(
+ match_pr, t_state.target_state);
+ }
+ }
+ /*
+ * After the set_throttling is called, the
+ * throttling notifier is called for every
+ * affected cpu to update the T-states.
+ * The notifier event is THROTTLING_POSTCHANGE
+ */
+ for_each_cpu_mask(i, online_throttling_cpus) {
+ t_state.cpu = i;
+ acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
+ &t_state);
+ }
/* restore the previous state */
set_cpus_allowed(current, saved_mask);
return ret;
@@ -757,6 +1050,7 @@ int acpi_processor_set_throttling(struct
int acpi_processor_get_throttling_info(struct acpi_processor *pr)
{
int result = 0;
+ struct acpi_processor_throttling *pthrottling;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
@@ -788,7 +1082,16 @@ int acpi_processor_get_throttling_info(s
&acpi_processor_set_throttling_ptc;
}
- acpi_processor_get_tsd(pr);
+ /*
+ * If TSD package for one CPU can't be parsed successfully, it means
+ * that this CPU will have no coordination with other CPUs.
+ */
+ if (acpi_processor_get_tsd(pr)) {
+ pthrottling = &pr->throttling;
+ pthrottling->tsd_valid_flag = 0;
+ cpu_set(pr->id, pthrottling->shared_cpu_map);
+ pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
+ }
/*
* PIIX4 Errata: We don't support throttling on the original PIIX4.
Index: linux-2.6.24-rc7/drivers/acpi/processor_core.c
===================================================================
--- linux-2.6.24-rc7.orig/drivers/acpi/processor_core.c
+++ linux-2.6.24-rc7/drivers/acpi/processor_core.c
@@ -1061,6 +1061,8 @@ static int __init acpi_processor_init(vo
acpi_processor_ppc_init();
+ acpi_processor_throttling_init();
+
return 0;
out_cpuidle:
-
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