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path: root/kernel/drivers/cpufreq/powernv-cpufreq.c
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Diffstat (limited to 'kernel/drivers/cpufreq/powernv-cpufreq.c')
-rw-r--r--kernel/drivers/cpufreq/powernv-cpufreq.c205
1 files changed, 190 insertions, 15 deletions
diff --git a/kernel/drivers/cpufreq/powernv-cpufreq.c b/kernel/drivers/cpufreq/powernv-cpufreq.c
index ebef0d827..cb501386e 100644
--- a/kernel/drivers/cpufreq/powernv-cpufreq.c
+++ b/kernel/drivers/cpufreq/powernv-cpufreq.c
@@ -27,20 +27,31 @@
#include <linux/smp.h>
#include <linux/of.h>
#include <linux/reboot.h>
+#include <linux/slab.h>
#include <asm/cputhreads.h>
#include <asm/firmware.h>
#include <asm/reg.h>
#include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */
+#include <asm/opal.h>
#define POWERNV_MAX_PSTATES 256
#define PMSR_PSAFE_ENABLE (1UL << 30)
#define PMSR_SPR_EM_DISABLE (1UL << 31)
#define PMSR_MAX(x) ((x >> 32) & 0xFF)
-#define PMSR_LP(x) ((x >> 48) & 0xFF)
static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1];
-static bool rebooting, throttled;
+static bool rebooting, throttled, occ_reset;
+
+static struct chip {
+ unsigned int id;
+ bool throttled;
+ cpumask_t mask;
+ struct work_struct throttle;
+ bool restore;
+} *chips;
+
+static int nr_chips;
/*
* Note: The set of pstates consists of contiguous integers, the
@@ -298,28 +309,41 @@ static inline unsigned int get_nominal_index(void)
return powernv_pstate_info.max - powernv_pstate_info.nominal;
}
-static void powernv_cpufreq_throttle_check(unsigned int cpu)
+static void powernv_cpufreq_throttle_check(void *data)
{
+ unsigned int cpu = smp_processor_id();
unsigned long pmsr;
- int pmsr_pmax, pmsr_lp;
+ int pmsr_pmax, i;
pmsr = get_pmspr(SPRN_PMSR);
+ for (i = 0; i < nr_chips; i++)
+ if (chips[i].id == cpu_to_chip_id(cpu))
+ break;
+
/* Check for Pmax Capping */
pmsr_pmax = (s8)PMSR_MAX(pmsr);
if (pmsr_pmax != powernv_pstate_info.max) {
- throttled = true;
- pr_info("CPU %d Pmax is reduced to %d\n", cpu, pmsr_pmax);
- pr_info("Max allowed Pstate is capped\n");
+ if (chips[i].throttled)
+ goto next;
+ chips[i].throttled = true;
+ if (pmsr_pmax < powernv_pstate_info.nominal)
+ pr_crit("CPU %d on Chip %u has Pmax reduced below nominal frequency (%d < %d)\n",
+ cpu, chips[i].id, pmsr_pmax,
+ powernv_pstate_info.nominal);
+ else
+ pr_info("CPU %d on Chip %u has Pmax reduced below turbo frequency (%d < %d)\n",
+ cpu, chips[i].id, pmsr_pmax,
+ powernv_pstate_info.max);
+ } else if (chips[i].throttled) {
+ chips[i].throttled = false;
+ pr_info("CPU %d on Chip %u has Pmax restored to %d\n", cpu,
+ chips[i].id, pmsr_pmax);
}
- /*
- * Check for Psafe by reading LocalPstate
- * or check if Psafe_mode_active is set in PMSR.
- */
- pmsr_lp = (s8)PMSR_LP(pmsr);
- if ((pmsr_lp < powernv_pstate_info.min) ||
- (pmsr & PMSR_PSAFE_ENABLE)) {
+ /* Check if Psafe_mode_active is set in PMSR. */
+next:
+ if (pmsr & PMSR_PSAFE_ENABLE) {
throttled = true;
pr_info("Pstate set to safe frequency\n");
}
@@ -350,7 +374,7 @@ static int powernv_cpufreq_target_index(struct cpufreq_policy *policy,
return 0;
if (!throttled)
- powernv_cpufreq_throttle_check(smp_processor_id());
+ powernv_cpufreq_throttle_check(NULL);
freq_data.pstate_id = powernv_freqs[new_index].driver_data;
@@ -395,6 +419,119 @@ static struct notifier_block powernv_cpufreq_reboot_nb = {
.notifier_call = powernv_cpufreq_reboot_notifier,
};
+void powernv_cpufreq_work_fn(struct work_struct *work)
+{
+ struct chip *chip = container_of(work, struct chip, throttle);
+ unsigned int cpu;
+ cpumask_var_t mask;
+
+ smp_call_function_any(&chip->mask,
+ powernv_cpufreq_throttle_check, NULL, 0);
+
+ if (!chip->restore)
+ return;
+
+ chip->restore = false;
+ cpumask_copy(mask, &chip->mask);
+ for_each_cpu_and(cpu, mask, cpu_online_mask) {
+ int index, tcpu;
+ struct cpufreq_policy policy;
+
+ cpufreq_get_policy(&policy, cpu);
+ cpufreq_frequency_table_target(&policy, policy.freq_table,
+ policy.cur,
+ CPUFREQ_RELATION_C, &index);
+ powernv_cpufreq_target_index(&policy, index);
+ for_each_cpu(tcpu, policy.cpus)
+ cpumask_clear_cpu(tcpu, mask);
+ }
+}
+
+static char throttle_reason[][30] = {
+ "No throttling",
+ "Power Cap",
+ "Processor Over Temperature",
+ "Power Supply Failure",
+ "Over Current",
+ "OCC Reset"
+ };
+
+static int powernv_cpufreq_occ_msg(struct notifier_block *nb,
+ unsigned long msg_type, void *_msg)
+{
+ struct opal_msg *msg = _msg;
+ struct opal_occ_msg omsg;
+ int i;
+
+ if (msg_type != OPAL_MSG_OCC)
+ return 0;
+
+ omsg.type = be64_to_cpu(msg->params[0]);
+
+ switch (omsg.type) {
+ case OCC_RESET:
+ occ_reset = true;
+ pr_info("OCC (On Chip Controller - enforces hard thermal/power limits) Resetting\n");
+ /*
+ * powernv_cpufreq_throttle_check() is called in
+ * target() callback which can detect the throttle state
+ * for governors like ondemand.
+ * But static governors will not call target() often thus
+ * report throttling here.
+ */
+ if (!throttled) {
+ throttled = true;
+ pr_crit("CPU frequency is throttled for duration\n");
+ }
+
+ break;
+ case OCC_LOAD:
+ pr_info("OCC Loading, CPU frequency is throttled until OCC is started\n");
+ break;
+ case OCC_THROTTLE:
+ omsg.chip = be64_to_cpu(msg->params[1]);
+ omsg.throttle_status = be64_to_cpu(msg->params[2]);
+
+ if (occ_reset) {
+ occ_reset = false;
+ throttled = false;
+ pr_info("OCC Active, CPU frequency is no longer throttled\n");
+
+ for (i = 0; i < nr_chips; i++) {
+ chips[i].restore = true;
+ schedule_work(&chips[i].throttle);
+ }
+
+ return 0;
+ }
+
+ if (omsg.throttle_status &&
+ omsg.throttle_status <= OCC_MAX_THROTTLE_STATUS)
+ pr_info("OCC: Chip %u Pmax reduced due to %s\n",
+ (unsigned int)omsg.chip,
+ throttle_reason[omsg.throttle_status]);
+ else if (!omsg.throttle_status)
+ pr_info("OCC: Chip %u %s\n", (unsigned int)omsg.chip,
+ throttle_reason[omsg.throttle_status]);
+ else
+ return 0;
+
+ for (i = 0; i < nr_chips; i++)
+ if (chips[i].id == omsg.chip) {
+ if (!omsg.throttle_status)
+ chips[i].restore = true;
+ schedule_work(&chips[i].throttle);
+ }
+ }
+ return 0;
+}
+
+static struct notifier_block powernv_cpufreq_opal_nb = {
+ .notifier_call = powernv_cpufreq_occ_msg,
+ .next = NULL,
+ .priority = 0,
+};
+
static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy)
{
struct powernv_smp_call_data freq_data;
@@ -414,6 +551,36 @@ static struct cpufreq_driver powernv_cpufreq_driver = {
.attr = powernv_cpu_freq_attr,
};
+static int init_chip_info(void)
+{
+ unsigned int chip[256];
+ unsigned int cpu, i;
+ unsigned int prev_chip_id = UINT_MAX;
+
+ for_each_possible_cpu(cpu) {
+ unsigned int id = cpu_to_chip_id(cpu);
+
+ if (prev_chip_id != id) {
+ prev_chip_id = id;
+ chip[nr_chips++] = id;
+ }
+ }
+
+ chips = kmalloc_array(nr_chips, sizeof(struct chip), GFP_KERNEL);
+ if (!chips)
+ return -ENOMEM;
+
+ for (i = 0; i < nr_chips; i++) {
+ chips[i].id = chip[i];
+ chips[i].throttled = false;
+ cpumask_copy(&chips[i].mask, cpumask_of_node(chip[i]));
+ INIT_WORK(&chips[i].throttle, powernv_cpufreq_work_fn);
+ chips[i].restore = false;
+ }
+
+ return 0;
+}
+
static int __init powernv_cpufreq_init(void)
{
int rc = 0;
@@ -429,7 +596,13 @@ static int __init powernv_cpufreq_init(void)
return rc;
}
+ /* Populate chip info */
+ rc = init_chip_info();
+ if (rc)
+ return rc;
+
register_reboot_notifier(&powernv_cpufreq_reboot_nb);
+ opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb);
return cpufreq_register_driver(&powernv_cpufreq_driver);
}
module_init(powernv_cpufreq_init);
@@ -437,6 +610,8 @@ module_init(powernv_cpufreq_init);
static void __exit powernv_cpufreq_exit(void)
{
unregister_reboot_notifier(&powernv_cpufreq_reboot_nb);
+ opal_message_notifier_unregister(OPAL_MSG_OCC,
+ &powernv_cpufreq_opal_nb);
cpufreq_unregister_driver(&powernv_cpufreq_driver);
}
module_exit(powernv_cpufreq_exit);