#include <asm/pSeries_reconfig.h>
#include "xics.h"
#include "plpar_wrappers.h"
+#include "offline_states.h"
/* This version can't take the spinlock, because it never returns */
static struct rtas_args rtas_stop_self_args = {
.rets = &rtas_stop_self_args.args[0],
};
+static DEFINE_PER_CPU(enum cpu_state_vals, preferred_offline_state) =
+ CPU_STATE_OFFLINE;
+static DEFINE_PER_CPU(enum cpu_state_vals, current_state) = CPU_STATE_OFFLINE;
+
+static enum cpu_state_vals default_offline_state = CPU_STATE_OFFLINE;
+
+static int cede_offline_enabled __read_mostly = 1;
+
+/*
+ * Enable/disable cede_offline when available.
+ */
+static int __init setup_cede_offline(char *str)
+{
+ if (!strcmp(str, "off"))
+ cede_offline_enabled = 0;
+ else if (!strcmp(str, "on"))
+ cede_offline_enabled = 1;
+ else
+ return 0;
+ return 1;
+}
+
+__setup("cede_offline=", setup_cede_offline);
+
+enum cpu_state_vals get_cpu_current_state(int cpu)
+{
+ return per_cpu(current_state, cpu);
+}
+
+void set_cpu_current_state(int cpu, enum cpu_state_vals state)
+{
+ per_cpu(current_state, cpu) = state;
+}
+
+enum cpu_state_vals get_preferred_offline_state(int cpu)
+{
+ return per_cpu(preferred_offline_state, cpu);
+}
+
+void set_preferred_offline_state(int cpu, enum cpu_state_vals state)
+{
+ per_cpu(preferred_offline_state, cpu) = state;
+}
+
+void set_default_offline_state(int cpu)
+{
+ per_cpu(preferred_offline_state, cpu) = default_offline_state;
+}
+
static void rtas_stop_self(void)
{
struct rtas_args *args = &rtas_stop_self_args;
static void pseries_mach_cpu_die(void)
{
+ unsigned int cpu = smp_processor_id();
+ unsigned int hwcpu = hard_smp_processor_id();
+ u8 cede_latency_hint = 0;
+
local_irq_disable();
idle_task_exit();
xics_teardown_cpu();
- unregister_slb_shadow(hard_smp_processor_id(), __pa(get_slb_shadow()));
- rtas_stop_self();
+
+ if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
+ set_cpu_current_state(cpu, CPU_STATE_INACTIVE);
+ cede_latency_hint = 2;
+
+ get_lppaca()->idle = 1;
+ if (!get_lppaca()->shared_proc)
+ get_lppaca()->donate_dedicated_cpu = 1;
+
+ printk(KERN_INFO
+ "cpu %u (hwid %u) ceding for offline with hint %d\n",
+ cpu, hwcpu, cede_latency_hint);
+ while (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
+ extended_cede_processor(cede_latency_hint);
+ printk(KERN_INFO "cpu %u (hwid %u) returned from cede.\n",
+ cpu, hwcpu);
+ printk(KERN_INFO
+ "Decrementer value = %x Timebase value = %llx\n",
+ get_dec(), get_tb());
+ }
+
+ printk(KERN_INFO "cpu %u (hwid %u) got prodded to go online\n",
+ cpu, hwcpu);
+
+ if (!get_lppaca()->shared_proc)
+ get_lppaca()->donate_dedicated_cpu = 0;
+ get_lppaca()->idle = 0;
+ }
+
+ if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) {
+ unregister_slb_shadow(hwcpu, __pa(get_slb_shadow()));
+
+ /*
+ * NOTE: Calling start_secondary() here for now to
+ * start new context.
+ * However, need to do it cleanly by resetting the
+ * stack pointer.
+ */
+ start_secondary();
+
+ } else if (get_preferred_offline_state(cpu) == CPU_STATE_OFFLINE) {
+
+ set_cpu_current_state(cpu, CPU_STATE_OFFLINE);
+ unregister_slb_shadow(hard_smp_processor_id(),
+ __pa(get_slb_shadow()));
+ rtas_stop_self();
+ }
+
/* Should never get here... */
BUG();
for(;;);
return 0;
}
+/*
+ * pseries_cpu_die: Wait for the cpu to die.
+ * @cpu: logical processor id of the CPU whose death we're awaiting.
+ *
+ * This function is called from the context of the thread which is performing
+ * the cpu-offline. Here we wait for long enough to allow the cpu in question
+ * to self-destroy so that the cpu-offline thread can send the CPU_DEAD
+ * notifications.
+ *
+ * OTOH, pseries_mach_cpu_die() is called by the @cpu when it wants to
+ * self-destruct.
+ */
static void pseries_cpu_die(unsigned int cpu)
{
int tries;
- int cpu_status;
+ int cpu_status = 1;
unsigned int pcpu = get_hard_smp_processor_id(cpu);
- for (tries = 0; tries < 25; tries++) {
- cpu_status = query_cpu_stopped(pcpu);
- if (cpu_status == 0 || cpu_status == -1)
- break;
- cpu_relax();
+ if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
+ cpu_status = 1;
+ for (tries = 0; tries < 1000; tries++) {
+ if (get_cpu_current_state(cpu) == CPU_STATE_INACTIVE) {
+ cpu_status = 0;
+ break;
+ }
+ cpu_relax();
+ }
+ } else if (get_preferred_offline_state(cpu) == CPU_STATE_OFFLINE) {
+
+ for (tries = 0; tries < 25; tries++) {
+ cpu_status = query_cpu_stopped(pcpu);
+ if (cpu_status == 0 || cpu_status == -1)
+ break;
+ cpu_relax();
+ }
}
+
if (cpu_status != 0) {
printk("Querying DEAD? cpu %i (%i) shows %i\n",
cpu, pcpu, cpu_status);
.notifier_call = pseries_smp_notifier,
};
+#define MAX_CEDE_LATENCY_LEVELS 4
+#define CEDE_LATENCY_PARAM_LENGTH 10
+#define CEDE_LATENCY_PARAM_MAX_LENGTH \
+ (MAX_CEDE_LATENCY_LEVELS * CEDE_LATENCY_PARAM_LENGTH * sizeof(char))
+#define CEDE_LATENCY_TOKEN 45
+
+static char cede_parameters[CEDE_LATENCY_PARAM_MAX_LENGTH];
+
+static int parse_cede_parameters(void)
+{
+ int call_status;
+
+ memset(cede_parameters, 0, CEDE_LATENCY_PARAM_MAX_LENGTH);
+ call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
+ NULL,
+ CEDE_LATENCY_TOKEN,
+ __pa(cede_parameters),
+ CEDE_LATENCY_PARAM_MAX_LENGTH);
+
+ if (call_status != 0)
+ printk(KERN_INFO "CEDE_LATENCY: \
+ %s %s Error calling get-system-parameter(0x%x)\n",
+ __FILE__, __func__, call_status);
+ else
+ printk(KERN_INFO "CEDE_LATENCY: \
+ get-system-parameter successful.\n");
+
+ return call_status;
+}
+
static int __init pseries_cpu_hotplug_init(void)
{
struct device_node *np;
const char *typep;
+ int cpu;
for_each_node_by_name(np, "interrupt-controller") {
typep = of_get_property(np, "compatible", NULL);
smp_ops->cpu_die = pseries_cpu_die;
/* Processors can be added/removed only on LPAR */
- if (firmware_has_feature(FW_FEATURE_LPAR))
+ if (firmware_has_feature(FW_FEATURE_LPAR)) {
pSeries_reconfig_notifier_register(&pseries_smp_nb);
+ cpu_maps_update_begin();
+ if (cede_offline_enabled && parse_cede_parameters() == 0) {
+ default_offline_state = CPU_STATE_INACTIVE;
+ for_each_online_cpu(cpu)
+ set_default_offline_state(cpu);
+ }
+ cpu_maps_update_done();
+ }
return 0;
}
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff