#include <asm/system.h>
#include <asm/rtas.h>
#include <asm/plpar_wrappers.h>
+#include <asm/pSeries_reconfig.h>
#include "mpic.h"
#define DBG(fmt...)
#endif
+/*
+ * The primary thread of each non-boot processor is recorded here before
+ * smp init.
+ */
+static cpumask_t of_spin_map;
+
extern void pSeries_secondary_smp_init(unsigned long);
+#ifdef CONFIG_HOTPLUG_CPU
+
/* Get state of physical CPU.
* Return codes:
* 0 - The processor is in the RTAS stopped state
return cpu_status;
}
-
-#ifdef CONFIG_HOTPLUG_CPU
-
int pSeries_cpu_disable(void)
{
systemcfg->processorCount--;
paca[cpu].cpu_start = 0;
}
-/* Search all cpu device nodes for an offline logical cpu. If a
- * device node has a "ibm,my-drc-index" property (meaning this is an
- * LPAR), paranoid-check whether we own the cpu. For each "thread"
- * of a cpu, if it is offline and has the same hw index as before,
- * grab that in preference.
+/*
+ * Update cpu_present_map and paca(s) for a new cpu node. The wrinkle
+ * here is that a cpu device node may represent up to two logical cpus
+ * in the SMT case. We must honor the assumption in other code that
+ * the logical ids for sibling SMT threads x and y are adjacent, such
+ * that x^1 == y and y^1 == x.
*/
-static unsigned int find_physical_cpu_to_start(unsigned int old_hwindex)
+static int pSeries_add_processor(struct device_node *np)
{
- struct device_node *np = NULL;
- unsigned int best = -1U;
+ unsigned int cpu;
+ cpumask_t candidate_map, tmp = CPU_MASK_NONE;
+ int err = -ENOSPC, len, nthreads, i;
+ u32 *intserv;
+
+ intserv = (u32 *)get_property(np, "ibm,ppc-interrupt-server#s", &len);
+ if (!intserv)
+ return 0;
- while ((np = of_find_node_by_type(np, "cpu"))) {
- int nr_threads, len;
- u32 *index = (u32 *)get_property(np, "ibm,my-drc-index", NULL);
- u32 *tid = (u32 *)
- get_property(np, "ibm,ppc-interrupt-server#s", &len);
+ nthreads = len / sizeof(u32);
+ for (i = 0; i < nthreads; i++)
+ cpu_set(i, tmp);
- if (!tid)
- tid = (u32 *)get_property(np, "reg", &len);
+ lock_cpu_hotplug();
- if (!tid)
- continue;
+ BUG_ON(!cpus_subset(cpu_present_map, cpu_possible_map));
- /* If there is a drc-index, make sure that we own
- * the cpu.
+ /* Get a bitmap of unoccupied slots. */
+ cpus_xor(candidate_map, cpu_possible_map, cpu_present_map);
+ if (cpus_empty(candidate_map)) {
+ /* If we get here, it most likely means that NR_CPUS is
+ * less than the partition's max processors setting.
*/
- if (index) {
- int state;
- int rc = rtas_get_sensor(9003, *index, &state);
- if (rc != 0 || state != 1)
- continue;
- }
+ printk(KERN_ERR "Cannot add cpu %s; this system configuration"
+ " supports %d logical cpus.\n", np->full_name,
+ cpus_weight(cpu_possible_map));
+ goto out_unlock;
+ }
+
+ while (!cpus_empty(tmp))
+ if (cpus_subset(tmp, candidate_map))
+ /* Found a range where we can insert the new cpu(s) */
+ break;
+ else
+ cpus_shift_left(tmp, tmp, nthreads);
+
+ if (cpus_empty(tmp)) {
+ printk(KERN_ERR "Unable to find space in cpu_present_map for"
+ " processor %s with %d thread(s)\n", np->name,
+ nthreads);
+ goto out_unlock;
+ }
+
+ for_each_cpu_mask(cpu, tmp) {
+ BUG_ON(cpu_isset(cpu, cpu_present_map));
+ cpu_set(cpu, cpu_present_map);
+ set_hard_smp_processor_id(cpu, *intserv++);
+ }
+ err = 0;
+out_unlock:
+ unlock_cpu_hotplug();
+ return err;
+}
- nr_threads = len / sizeof(u32);
+/*
+ * Update the present map for a cpu node which is going away, and set
+ * the hard id in the paca(s) to -1 to be consistent with boot time
+ * convention for non-present cpus.
+ */
+static void pSeries_remove_processor(struct device_node *np)
+{
+ unsigned int cpu;
+ int len, nthreads, i;
+ u32 *intserv;
- while (nr_threads--) {
- if (0 == query_cpu_stopped(tid[nr_threads])) {
- best = tid[nr_threads];
- if (best == old_hwindex)
- goto out;
- }
+ intserv = (u32 *)get_property(np, "ibm,ppc-interrupt-server#s", &len);
+ if (!intserv)
+ return;
+
+ nthreads = len / sizeof(u32);
+
+ lock_cpu_hotplug();
+ for (i = 0; i < nthreads; i++) {
+ for_each_present_cpu(cpu) {
+ if (get_hard_smp_processor_id(cpu) != intserv[i])
+ continue;
+ BUG_ON(cpu_online(cpu));
+ cpu_clear(cpu, cpu_present_map);
+ set_hard_smp_processor_id(cpu, -1);
+ break;
}
+ if (cpu == NR_CPUS)
+ printk(KERN_WARNING "Could not find cpu to remove "
+ "with physical id 0x%x\n", intserv[i]);
}
-out:
- of_node_put(np);
- return best;
+ unlock_cpu_hotplug();
}
+static int pSeries_smp_notifier(struct notifier_block *nb, unsigned long action, void *node)
+{
+ int err = NOTIFY_OK;
+
+ switch (action) {
+ case PSERIES_RECONFIG_ADD:
+ if (pSeries_add_processor(node))
+ err = NOTIFY_BAD;
+ break;
+ case PSERIES_RECONFIG_REMOVE:
+ pSeries_remove_processor(node);
+ break;
+ default:
+ err = NOTIFY_DONE;
+ break;
+ }
+ return err;
+}
+
+static struct notifier_block pSeries_smp_nb = {
+ .notifier_call = pSeries_smp_notifier,
+};
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
/**
* smp_startup_cpu() - start the given cpu
*
- * At boot time, there is nothing to do. At run-time, call RTAS with
- * the appropriate start location, if the cpu is in the RTAS stopped
- * state.
+ * At boot time, there is nothing to do for primary threads which were
+ * started from Open Firmware. For anything else, call RTAS with the
+ * appropriate start location.
*
* Returns:
* 0 - failure
pSeries_secondary_smp_init));
unsigned int pcpu;
- /* At boot time the cpus are already spinning in hold
- * loops, so nothing to do. */
- if (system_state < SYSTEM_RUNNING)
+ if (cpu_isset(lcpu, of_spin_map))
+ /* Already started by OF and sitting in spin loop */
return 1;
- pcpu = find_physical_cpu_to_start(get_hard_smp_processor_id(lcpu));
- if (pcpu == -1U) {
- printk(KERN_INFO "No more cpus available, failing\n");
- return 0;
- }
+ pcpu = get_hard_smp_processor_id(lcpu);
/* Fixup atomic count: it exited inside IRQ handler. */
paca[lcpu].__current->thread_info->preempt_count = 0;
- /* At boot this is done in prom.c. */
- paca[lcpu].hw_cpu_id = pcpu;
-
status = rtas_call(rtas_token("start-cpu"), 3, 1, NULL,
pcpu, start_here, lcpu);
if (status != 0) {
}
return 1;
}
-#else /* ... CONFIG_HOTPLUG_CPU */
-static inline int __devinit smp_startup_cpu(unsigned int lcpu)
-{
- return 1;
-}
-#endif /* CONFIG_HOTPLUG_CPU */
static inline void smp_xics_do_message(int cpu, int msg)
{
if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR)
vpa_init(cpu);
- /*
- * Put the calling processor into the GIQ. This is really only
- * necessary from a secondary thread as the OF start-cpu interface
- * performs this function for us on primary threads.
- */
- rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
- (1UL << interrupt_server_size) - 1 - default_distrib_server, 1);
+ cpu_clear(cpu, of_spin_map);
+
}
static DEFINE_SPINLOCK(timebase_lock);
paca[nr].cpu_start = 1;
}
+static int smp_pSeries_cpu_bootable(unsigned int nr)
+{
+ /* Special case - we inhibit secondary thread startup
+ * during boot if the user requests it. Odd-numbered
+ * cpus are assumed to be secondary threads.
+ */
+ if (system_state < SYSTEM_RUNNING &&
+ cur_cpu_spec->cpu_features & CPU_FTR_SMT &&
+ !smt_enabled_at_boot && nr % 2 != 0)
+ return 0;
+
+ return 1;
+}
+
static struct smp_ops_t pSeries_mpic_smp_ops = {
.message_pass = smp_mpic_message_pass,
.probe = smp_mpic_probe,
.probe = smp_xics_probe,
.kick_cpu = smp_pSeries_kick_cpu,
.setup_cpu = smp_xics_setup_cpu,
+ .cpu_bootable = smp_pSeries_cpu_bootable,
};
/* This is called very early */
void __init smp_init_pSeries(void)
{
- int ret, i;
+ int i;
DBG(" -> smp_init_pSeries()\n");
#ifdef CONFIG_HOTPLUG_CPU
smp_ops->cpu_disable = pSeries_cpu_disable;
smp_ops->cpu_die = pSeries_cpu_die;
+
+ /* Processors can be added/removed only on LPAR */
+ if (systemcfg->platform == PLATFORM_PSERIES_LPAR)
+ pSeries_reconfig_notifier_register(&pSeries_smp_nb);
#endif
- /* Start secondary threads on SMT systems; primary threads
- * are already in the running state.
- */
- for_each_present_cpu(i) {
- if (query_cpu_stopped(get_hard_smp_processor_id(i)) == 0) {
- printk("%16.16x : starting thread\n", i);
- DBG("%16.16x : starting thread\n", i);
- rtas_call(rtas_token("start-cpu"), 3, 1, &ret,
- get_hard_smp_processor_id(i),
- __pa((u32)*((unsigned long *)
- pSeries_secondary_smp_init)),
- i);
+ /* Mark threads which are still spinning in hold loops. */
+ if (cur_cpu_spec->cpu_features & CPU_FTR_SMT)
+ for_each_present_cpu(i) {
+ if (i % 2 == 0)
+ /*
+ * Even-numbered logical cpus correspond to
+ * primary threads.
+ */
+ cpu_set(i, of_spin_map);
}
- }
+ else
+ of_spin_map = cpu_present_map;
+
+ cpu_clear(boot_cpuid, of_spin_map);
/* Non-lpar has additional take/give timebase */
if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
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