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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/kernel/smp.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
-rw-r--r--arch/powerpc/kernel/smp.c1770
1 files changed, 1770 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
new file mode 100644
index 000000000..0da6e5916
--- /dev/null
+++ b/arch/powerpc/kernel/smp.c
@@ -0,0 +1,1770 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SMP support for ppc.
+ *
+ * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
+ * deal of code from the sparc and intel versions.
+ *
+ * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
+ *
+ * PowerPC-64 Support added by Dave Engebretsen, Peter Bergner, and
+ * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/task_stack.h>
+#include <linux/sched/topology.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/cache.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+#include <linux/topology.h>
+#include <linux/profile.h>
+#include <linux/processor.h>
+#include <linux/random.h>
+#include <linux/stackprotector.h>
+#include <linux/pgtable.h>
+#include <linux/clockchips.h>
+#include <linux/kexec.h>
+
+#include <asm/ptrace.h>
+#include <linux/atomic.h>
+#include <asm/irq.h>
+#include <asm/hw_irq.h>
+#include <asm/kvm_ppc.h>
+#include <asm/dbell.h>
+#include <asm/page.h>
+#include <asm/smp.h>
+#include <asm/time.h>
+#include <asm/machdep.h>
+#include <asm/cputhreads.h>
+#include <asm/cputable.h>
+#include <asm/mpic.h>
+#include <asm/vdso_datapage.h>
+#ifdef CONFIG_PPC64
+#include <asm/paca.h>
+#endif
+#include <asm/vdso.h>
+#include <asm/debug.h>
+#include <asm/cpu_has_feature.h>
+#include <asm/ftrace.h>
+#include <asm/kup.h>
+#include <asm/fadump.h>
+
+#ifdef DEBUG
+#include <asm/udbg.h>
+#define DBG(fmt...) udbg_printf(fmt)
+#else
+#define DBG(fmt...)
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+/* State of each CPU during hotplug phases */
+static DEFINE_PER_CPU(int, cpu_state) = { 0 };
+#endif
+
+struct task_struct *secondary_current;
+bool has_big_cores;
+bool coregroup_enabled;
+bool thread_group_shares_l2;
+bool thread_group_shares_l3;
+
+DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
+DEFINE_PER_CPU(cpumask_var_t, cpu_smallcore_map);
+DEFINE_PER_CPU(cpumask_var_t, cpu_l2_cache_map);
+DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
+static DEFINE_PER_CPU(cpumask_var_t, cpu_coregroup_map);
+
+EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
+EXPORT_PER_CPU_SYMBOL(cpu_l2_cache_map);
+EXPORT_PER_CPU_SYMBOL(cpu_core_map);
+EXPORT_SYMBOL_GPL(has_big_cores);
+
+enum {
+#ifdef CONFIG_SCHED_SMT
+ smt_idx,
+#endif
+ cache_idx,
+ mc_idx,
+ die_idx,
+};
+
+#define MAX_THREAD_LIST_SIZE 8
+#define THREAD_GROUP_SHARE_L1 1
+#define THREAD_GROUP_SHARE_L2_L3 2
+struct thread_groups {
+ unsigned int property;
+ unsigned int nr_groups;
+ unsigned int threads_per_group;
+ unsigned int thread_list[MAX_THREAD_LIST_SIZE];
+};
+
+/* Maximum number of properties that groups of threads within a core can share */
+#define MAX_THREAD_GROUP_PROPERTIES 2
+
+struct thread_groups_list {
+ unsigned int nr_properties;
+ struct thread_groups property_tgs[MAX_THREAD_GROUP_PROPERTIES];
+};
+
+static struct thread_groups_list tgl[NR_CPUS] __initdata;
+/*
+ * On big-cores system, thread_group_l1_cache_map for each CPU corresponds to
+ * the set its siblings that share the L1-cache.
+ */
+DEFINE_PER_CPU(cpumask_var_t, thread_group_l1_cache_map);
+
+/*
+ * On some big-cores system, thread_group_l2_cache_map for each CPU
+ * corresponds to the set its siblings within the core that share the
+ * L2-cache.
+ */
+DEFINE_PER_CPU(cpumask_var_t, thread_group_l2_cache_map);
+
+/*
+ * On P10, thread_group_l3_cache_map for each CPU is equal to the
+ * thread_group_l2_cache_map
+ */
+DEFINE_PER_CPU(cpumask_var_t, thread_group_l3_cache_map);
+
+/* SMP operations for this machine */
+struct smp_ops_t *smp_ops;
+
+/* Can't be static due to PowerMac hackery */
+volatile unsigned int cpu_callin_map[NR_CPUS];
+
+int smt_enabled_at_boot = 1;
+
+/*
+ * Returns 1 if the specified cpu should be brought up during boot.
+ * Used to inhibit booting threads if they've been disabled or
+ * limited on the command line
+ */
+int smp_generic_cpu_bootable(unsigned int nr)
+{
+ /* Special case - we inhibit secondary thread startup
+ * during boot if the user requests it.
+ */
+ if (system_state < SYSTEM_RUNNING && cpu_has_feature(CPU_FTR_SMT)) {
+ if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
+ return 0;
+ if (smt_enabled_at_boot
+ && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
+ return 0;
+ }
+
+ return 1;
+}
+
+
+#ifdef CONFIG_PPC64
+int smp_generic_kick_cpu(int nr)
+{
+ if (nr < 0 || nr >= nr_cpu_ids)
+ return -EINVAL;
+
+ /*
+ * The processor is currently spinning, waiting for the
+ * cpu_start field to become non-zero After we set cpu_start,
+ * the processor will continue on to secondary_start
+ */
+ if (!paca_ptrs[nr]->cpu_start) {
+ paca_ptrs[nr]->cpu_start = 1;
+ smp_mb();
+ return 0;
+ }
+
+#ifdef CONFIG_HOTPLUG_CPU
+ /*
+ * Ok it's not there, so it might be soft-unplugged, let's
+ * try to bring it back
+ */
+ generic_set_cpu_up(nr);
+ smp_wmb();
+ smp_send_reschedule(nr);
+#endif /* CONFIG_HOTPLUG_CPU */
+
+ return 0;
+}
+#endif /* CONFIG_PPC64 */
+
+static irqreturn_t call_function_action(int irq, void *data)
+{
+ generic_smp_call_function_interrupt();
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t reschedule_action(int irq, void *data)
+{
+ scheduler_ipi();
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+static irqreturn_t tick_broadcast_ipi_action(int irq, void *data)
+{
+ timer_broadcast_interrupt();
+ return IRQ_HANDLED;
+}
+#endif
+
+#ifdef CONFIG_NMI_IPI
+static irqreturn_t nmi_ipi_action(int irq, void *data)
+{
+ smp_handle_nmi_ipi(get_irq_regs());
+ return IRQ_HANDLED;
+}
+#endif
+
+static irq_handler_t smp_ipi_action[] = {
+ [PPC_MSG_CALL_FUNCTION] = call_function_action,
+ [PPC_MSG_RESCHEDULE] = reschedule_action,
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+ [PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_action,
+#endif
+#ifdef CONFIG_NMI_IPI
+ [PPC_MSG_NMI_IPI] = nmi_ipi_action,
+#endif
+};
+
+/*
+ * The NMI IPI is a fallback and not truly non-maskable. It is simpler
+ * than going through the call function infrastructure, and strongly
+ * serialized, so it is more appropriate for debugging.
+ */
+const char *smp_ipi_name[] = {
+ [PPC_MSG_CALL_FUNCTION] = "ipi call function",
+ [PPC_MSG_RESCHEDULE] = "ipi reschedule",
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+ [PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast",
+#endif
+#ifdef CONFIG_NMI_IPI
+ [PPC_MSG_NMI_IPI] = "nmi ipi",
+#endif
+};
+
+/* optional function to request ipi, for controllers with >= 4 ipis */
+int smp_request_message_ipi(int virq, int msg)
+{
+ int err;
+
+ if (msg < 0 || msg > PPC_MSG_NMI_IPI)
+ return -EINVAL;
+#ifndef CONFIG_NMI_IPI
+ if (msg == PPC_MSG_NMI_IPI)
+ return 1;
+#endif
+
+ err = request_irq(virq, smp_ipi_action[msg],
+ IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND,
+ smp_ipi_name[msg], NULL);
+ WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
+ virq, smp_ipi_name[msg], err);
+
+ return err;
+}
+
+#ifdef CONFIG_PPC_SMP_MUXED_IPI
+struct cpu_messages {
+ long messages; /* current messages */
+};
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
+
+void smp_muxed_ipi_set_message(int cpu, int msg)
+{
+ struct cpu_messages *info = &per_cpu(ipi_message, cpu);
+ char *message = (char *)&info->messages;
+
+ /*
+ * Order previous accesses before accesses in the IPI handler.
+ */
+ smp_mb();
+ message[msg] = 1;
+}
+
+void smp_muxed_ipi_message_pass(int cpu, int msg)
+{
+ smp_muxed_ipi_set_message(cpu, msg);
+
+ /*
+ * cause_ipi functions are required to include a full barrier
+ * before doing whatever causes the IPI.
+ */
+ smp_ops->cause_ipi(cpu);
+}
+
+#ifdef __BIG_ENDIAN__
+#define IPI_MESSAGE(A) (1uL << ((BITS_PER_LONG - 8) - 8 * (A)))
+#else
+#define IPI_MESSAGE(A) (1uL << (8 * (A)))
+#endif
+
+irqreturn_t smp_ipi_demux(void)
+{
+ mb(); /* order any irq clear */
+
+ return smp_ipi_demux_relaxed();
+}
+
+/* sync-free variant. Callers should ensure synchronization */
+irqreturn_t smp_ipi_demux_relaxed(void)
+{
+ struct cpu_messages *info;
+ unsigned long all;
+
+ info = this_cpu_ptr(&ipi_message);
+ do {
+ all = xchg(&info->messages, 0);
+#if defined(CONFIG_KVM_XICS) && defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE)
+ /*
+ * Must check for PPC_MSG_RM_HOST_ACTION messages
+ * before PPC_MSG_CALL_FUNCTION messages because when
+ * a VM is destroyed, we call kick_all_cpus_sync()
+ * to ensure that any pending PPC_MSG_RM_HOST_ACTION
+ * messages have completed before we free any VCPUs.
+ */
+ if (all & IPI_MESSAGE(PPC_MSG_RM_HOST_ACTION))
+ kvmppc_xics_ipi_action();
+#endif
+ if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION))
+ generic_smp_call_function_interrupt();
+ if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
+ scheduler_ipi();
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+ if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST))
+ timer_broadcast_interrupt();
+#endif
+#ifdef CONFIG_NMI_IPI
+ if (all & IPI_MESSAGE(PPC_MSG_NMI_IPI))
+ nmi_ipi_action(0, NULL);
+#endif
+ } while (info->messages);
+
+ return IRQ_HANDLED;
+}
+#endif /* CONFIG_PPC_SMP_MUXED_IPI */
+
+static inline void do_message_pass(int cpu, int msg)
+{
+ if (smp_ops->message_pass)
+ smp_ops->message_pass(cpu, msg);
+#ifdef CONFIG_PPC_SMP_MUXED_IPI
+ else
+ smp_muxed_ipi_message_pass(cpu, msg);
+#endif
+}
+
+void smp_send_reschedule(int cpu)
+{
+ if (likely(smp_ops))
+ do_message_pass(cpu, PPC_MSG_RESCHEDULE);
+}
+EXPORT_SYMBOL_GPL(smp_send_reschedule);
+
+void arch_send_call_function_single_ipi(int cpu)
+{
+ do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
+}
+
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
+{
+ unsigned int cpu;
+
+ for_each_cpu(cpu, mask)
+ do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
+}
+
+#ifdef CONFIG_NMI_IPI
+
+/*
+ * "NMI IPI" system.
+ *
+ * NMI IPIs may not be recoverable, so should not be used as ongoing part of
+ * a running system. They can be used for crash, debug, halt/reboot, etc.
+ *
+ * The IPI call waits with interrupts disabled until all targets enter the
+ * NMI handler, then returns. Subsequent IPIs can be issued before targets
+ * have returned from their handlers, so there is no guarantee about
+ * concurrency or re-entrancy.
+ *
+ * A new NMI can be issued before all targets exit the handler.
+ *
+ * The IPI call may time out without all targets entering the NMI handler.
+ * In that case, there is some logic to recover (and ignore subsequent
+ * NMI interrupts that may eventually be raised), but the platform interrupt
+ * handler may not be able to distinguish this from other exception causes,
+ * which may cause a crash.
+ */
+
+static atomic_t __nmi_ipi_lock = ATOMIC_INIT(0);
+static struct cpumask nmi_ipi_pending_mask;
+static bool nmi_ipi_busy = false;
+static void (*nmi_ipi_function)(struct pt_regs *) = NULL;
+
+noinstr static void nmi_ipi_lock_start(unsigned long *flags)
+{
+ raw_local_irq_save(*flags);
+ hard_irq_disable();
+ while (arch_atomic_cmpxchg(&__nmi_ipi_lock, 0, 1) == 1) {
+ raw_local_irq_restore(*flags);
+ spin_until_cond(arch_atomic_read(&__nmi_ipi_lock) == 0);
+ raw_local_irq_save(*flags);
+ hard_irq_disable();
+ }
+}
+
+noinstr static void nmi_ipi_lock(void)
+{
+ while (arch_atomic_cmpxchg(&__nmi_ipi_lock, 0, 1) == 1)
+ spin_until_cond(arch_atomic_read(&__nmi_ipi_lock) == 0);
+}
+
+noinstr static void nmi_ipi_unlock(void)
+{
+ smp_mb();
+ WARN_ON(arch_atomic_read(&__nmi_ipi_lock) != 1);
+ arch_atomic_set(&__nmi_ipi_lock, 0);
+}
+
+noinstr static void nmi_ipi_unlock_end(unsigned long *flags)
+{
+ nmi_ipi_unlock();
+ raw_local_irq_restore(*flags);
+}
+
+/*
+ * Platform NMI handler calls this to ack
+ */
+noinstr int smp_handle_nmi_ipi(struct pt_regs *regs)
+{
+ void (*fn)(struct pt_regs *) = NULL;
+ unsigned long flags;
+ int me = raw_smp_processor_id();
+ int ret = 0;
+
+ /*
+ * Unexpected NMIs are possible here because the interrupt may not
+ * be able to distinguish NMI IPIs from other types of NMIs, or
+ * because the caller may have timed out.
+ */
+ nmi_ipi_lock_start(&flags);
+ if (cpumask_test_cpu(me, &nmi_ipi_pending_mask)) {
+ cpumask_clear_cpu(me, &nmi_ipi_pending_mask);
+ fn = READ_ONCE(nmi_ipi_function);
+ WARN_ON_ONCE(!fn);
+ ret = 1;
+ }
+ nmi_ipi_unlock_end(&flags);
+
+ if (fn)
+ fn(regs);
+
+ return ret;
+}
+
+static void do_smp_send_nmi_ipi(int cpu, bool safe)
+{
+ if (!safe && smp_ops->cause_nmi_ipi && smp_ops->cause_nmi_ipi(cpu))
+ return;
+
+ if (cpu >= 0) {
+ do_message_pass(cpu, PPC_MSG_NMI_IPI);
+ } else {
+ int c;
+
+ for_each_online_cpu(c) {
+ if (c == raw_smp_processor_id())
+ continue;
+ do_message_pass(c, PPC_MSG_NMI_IPI);
+ }
+ }
+}
+
+/*
+ * - cpu is the target CPU (must not be this CPU), or NMI_IPI_ALL_OTHERS.
+ * - fn is the target callback function.
+ * - delay_us > 0 is the delay before giving up waiting for targets to
+ * begin executing the handler, == 0 specifies indefinite delay.
+ */
+static int __smp_send_nmi_ipi(int cpu, void (*fn)(struct pt_regs *),
+ u64 delay_us, bool safe)
+{
+ unsigned long flags;
+ int me = raw_smp_processor_id();
+ int ret = 1;
+
+ BUG_ON(cpu == me);
+ BUG_ON(cpu < 0 && cpu != NMI_IPI_ALL_OTHERS);
+
+ if (unlikely(!smp_ops))
+ return 0;
+
+ nmi_ipi_lock_start(&flags);
+ while (nmi_ipi_busy) {
+ nmi_ipi_unlock_end(&flags);
+ spin_until_cond(!nmi_ipi_busy);
+ nmi_ipi_lock_start(&flags);
+ }
+ nmi_ipi_busy = true;
+ nmi_ipi_function = fn;
+
+ WARN_ON_ONCE(!cpumask_empty(&nmi_ipi_pending_mask));
+
+ if (cpu < 0) {
+ /* ALL_OTHERS */
+ cpumask_copy(&nmi_ipi_pending_mask, cpu_online_mask);
+ cpumask_clear_cpu(me, &nmi_ipi_pending_mask);
+ } else {
+ cpumask_set_cpu(cpu, &nmi_ipi_pending_mask);
+ }
+
+ nmi_ipi_unlock();
+
+ /* Interrupts remain hard disabled */
+
+ do_smp_send_nmi_ipi(cpu, safe);
+
+ nmi_ipi_lock();
+ /* nmi_ipi_busy is set here, so unlock/lock is okay */
+ while (!cpumask_empty(&nmi_ipi_pending_mask)) {
+ nmi_ipi_unlock();
+ udelay(1);
+ nmi_ipi_lock();
+ if (delay_us) {
+ delay_us--;
+ if (!delay_us)
+ break;
+ }
+ }
+
+ if (!cpumask_empty(&nmi_ipi_pending_mask)) {
+ /* Timeout waiting for CPUs to call smp_handle_nmi_ipi */
+ ret = 0;
+ cpumask_clear(&nmi_ipi_pending_mask);
+ }
+
+ nmi_ipi_function = NULL;
+ nmi_ipi_busy = false;
+
+ nmi_ipi_unlock_end(&flags);
+
+ return ret;
+}
+
+int smp_send_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us)
+{
+ return __smp_send_nmi_ipi(cpu, fn, delay_us, false);
+}
+
+int smp_send_safe_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us)
+{
+ return __smp_send_nmi_ipi(cpu, fn, delay_us, true);
+}
+#endif /* CONFIG_NMI_IPI */
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+void tick_broadcast(const struct cpumask *mask)
+{
+ unsigned int cpu;
+
+ for_each_cpu(cpu, mask)
+ do_message_pass(cpu, PPC_MSG_TICK_BROADCAST);
+}
+#endif
+
+#ifdef CONFIG_DEBUGGER
+static void debugger_ipi_callback(struct pt_regs *regs)
+{
+ debugger_ipi(regs);
+}
+
+void smp_send_debugger_break(void)
+{
+ smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, debugger_ipi_callback, 1000000);
+}
+#endif
+
+#ifdef CONFIG_KEXEC_CORE
+void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
+{
+ int cpu;
+
+ smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, crash_ipi_callback, 1000000);
+ if (kdump_in_progress() && crash_wake_offline) {
+ for_each_present_cpu(cpu) {
+ if (cpu_online(cpu))
+ continue;
+ /*
+ * crash_ipi_callback will wait for
+ * all cpus, including offline CPUs.
+ * We don't care about nmi_ipi_function.
+ * Offline cpus will jump straight into
+ * crash_ipi_callback, we can skip the
+ * entire NMI dance and waiting for
+ * cpus to clear pending mask, etc.
+ */
+ do_smp_send_nmi_ipi(cpu, false);
+ }
+ }
+}
+#endif
+
+void crash_smp_send_stop(void)
+{
+ static bool stopped = false;
+
+ /*
+ * In case of fadump, register data for all CPUs is captured by f/w
+ * on ibm,os-term rtas call. Skip IPI callbacks to other CPUs before
+ * this rtas call to avoid tricky post processing of those CPUs'
+ * backtraces.
+ */
+ if (should_fadump_crash())
+ return;
+
+ if (stopped)
+ return;
+
+ stopped = true;
+
+#ifdef CONFIG_KEXEC_CORE
+ if (kexec_crash_image) {
+ crash_kexec_prepare();
+ return;
+ }
+#endif
+
+ smp_send_stop();
+}
+
+#ifdef CONFIG_NMI_IPI
+static void nmi_stop_this_cpu(struct pt_regs *regs)
+{
+ /*
+ * IRQs are already hard disabled by the smp_handle_nmi_ipi.
+ */
+ set_cpu_online(smp_processor_id(), false);
+
+ spin_begin();
+ while (1)
+ spin_cpu_relax();
+}
+
+void smp_send_stop(void)
+{
+ smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, nmi_stop_this_cpu, 1000000);
+}
+
+#else /* CONFIG_NMI_IPI */
+
+static void stop_this_cpu(void *dummy)
+{
+ hard_irq_disable();
+
+ /*
+ * Offlining CPUs in stop_this_cpu can result in scheduler warnings,
+ * (see commit de6e5d38417e), but printk_safe_flush_on_panic() wants
+ * to know other CPUs are offline before it breaks locks to flush
+ * printk buffers, in case we panic()ed while holding the lock.
+ */
+ set_cpu_online(smp_processor_id(), false);
+
+ spin_begin();
+ while (1)
+ spin_cpu_relax();
+}
+
+void smp_send_stop(void)
+{
+ static bool stopped = false;
+
+ /*
+ * Prevent waiting on csd lock from a previous smp_send_stop.
+ * This is racy, but in general callers try to do the right
+ * thing and only fire off one smp_send_stop (e.g., see
+ * kernel/panic.c)
+ */
+ if (stopped)
+ return;
+
+ stopped = true;
+
+ smp_call_function(stop_this_cpu, NULL, 0);
+}
+#endif /* CONFIG_NMI_IPI */
+
+static struct task_struct *current_set[NR_CPUS];
+
+static void smp_store_cpu_info(int id)
+{
+ per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
+#ifdef CONFIG_PPC_E500
+ per_cpu(next_tlbcam_idx, id)
+ = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
+#endif
+}
+
+/*
+ * Relationships between CPUs are maintained in a set of per-cpu cpumasks so
+ * rather than just passing around the cpumask we pass around a function that
+ * returns the that cpumask for the given CPU.
+ */
+static void set_cpus_related(int i, int j, struct cpumask *(*get_cpumask)(int))
+{
+ cpumask_set_cpu(i, get_cpumask(j));
+ cpumask_set_cpu(j, get_cpumask(i));
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void set_cpus_unrelated(int i, int j,
+ struct cpumask *(*get_cpumask)(int))
+{
+ cpumask_clear_cpu(i, get_cpumask(j));
+ cpumask_clear_cpu(j, get_cpumask(i));
+}
+#endif
+
+/*
+ * Extends set_cpus_related. Instead of setting one CPU at a time in
+ * dstmask, set srcmask at oneshot. dstmask should be super set of srcmask.
+ */
+static void or_cpumasks_related(int i, int j, struct cpumask *(*srcmask)(int),
+ struct cpumask *(*dstmask)(int))
+{
+ struct cpumask *mask;
+ int k;
+
+ mask = srcmask(j);
+ for_each_cpu(k, srcmask(i))
+ cpumask_or(dstmask(k), dstmask(k), mask);
+
+ if (i == j)
+ return;
+
+ mask = srcmask(i);
+ for_each_cpu(k, srcmask(j))
+ cpumask_or(dstmask(k), dstmask(k), mask);
+}
+
+/*
+ * parse_thread_groups: Parses the "ibm,thread-groups" device tree
+ * property for the CPU device node @dn and stores
+ * the parsed output in the thread_groups_list
+ * structure @tglp.
+ *
+ * @dn: The device node of the CPU device.
+ * @tglp: Pointer to a thread group list structure into which the parsed
+ * output of "ibm,thread-groups" is stored.
+ *
+ * ibm,thread-groups[0..N-1] array defines which group of threads in
+ * the CPU-device node can be grouped together based on the property.
+ *
+ * This array can represent thread groupings for multiple properties.
+ *
+ * ibm,thread-groups[i + 0] tells us the property based on which the
+ * threads are being grouped together. If this value is 1, it implies
+ * that the threads in the same group share L1, translation cache. If
+ * the value is 2, it implies that the threads in the same group share
+ * the same L2 cache.
+ *
+ * ibm,thread-groups[i+1] tells us how many such thread groups exist for the
+ * property ibm,thread-groups[i]
+ *
+ * ibm,thread-groups[i+2] tells us the number of threads in each such
+ * group.
+ * Suppose k = (ibm,thread-groups[i+1] * ibm,thread-groups[i+2]), then,
+ *
+ * ibm,thread-groups[i+3..i+k+2] (is the list of threads identified by
+ * "ibm,ppc-interrupt-server#s" arranged as per their membership in
+ * the grouping.
+ *
+ * Example:
+ * If "ibm,thread-groups" = [1,2,4,8,10,12,14,9,11,13,15,2,2,4,8,10,12,14,9,11,13,15]
+ * This can be decomposed up into two consecutive arrays:
+ * a) [1,2,4,8,10,12,14,9,11,13,15]
+ * b) [2,2,4,8,10,12,14,9,11,13,15]
+ *
+ * where in,
+ *
+ * a) provides information of Property "1" being shared by "2" groups,
+ * each with "4" threads each. The "ibm,ppc-interrupt-server#s" of
+ * the first group is {8,10,12,14} and the
+ * "ibm,ppc-interrupt-server#s" of the second group is
+ * {9,11,13,15}. Property "1" is indicative of the thread in the
+ * group sharing L1 cache, translation cache and Instruction Data
+ * flow.
+ *
+ * b) provides information of Property "2" being shared by "2" groups,
+ * each group with "4" threads. The "ibm,ppc-interrupt-server#s" of
+ * the first group is {8,10,12,14} and the
+ * "ibm,ppc-interrupt-server#s" of the second group is
+ * {9,11,13,15}. Property "2" indicates that the threads in each
+ * group share the L2-cache.
+ *
+ * Returns 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ */
+static int parse_thread_groups(struct device_node *dn,
+ struct thread_groups_list *tglp)
+{
+ unsigned int property_idx = 0;
+ u32 *thread_group_array;
+ size_t total_threads;
+ int ret = 0, count;
+ u32 *thread_list;
+ int i = 0;
+
+ count = of_property_count_u32_elems(dn, "ibm,thread-groups");
+ thread_group_array = kcalloc(count, sizeof(u32), GFP_KERNEL);
+ ret = of_property_read_u32_array(dn, "ibm,thread-groups",
+ thread_group_array, count);
+ if (ret)
+ goto out_free;
+
+ while (i < count && property_idx < MAX_THREAD_GROUP_PROPERTIES) {
+ int j;
+ struct thread_groups *tg = &tglp->property_tgs[property_idx++];
+
+ tg->property = thread_group_array[i];
+ tg->nr_groups = thread_group_array[i + 1];
+ tg->threads_per_group = thread_group_array[i + 2];
+ total_threads = tg->nr_groups * tg->threads_per_group;
+
+ thread_list = &thread_group_array[i + 3];
+
+ for (j = 0; j < total_threads; j++)
+ tg->thread_list[j] = thread_list[j];
+ i = i + 3 + total_threads;
+ }
+
+ tglp->nr_properties = property_idx;
+
+out_free:
+ kfree(thread_group_array);
+ return ret;
+}
+
+/*
+ * get_cpu_thread_group_start : Searches the thread group in tg->thread_list
+ * that @cpu belongs to.
+ *
+ * @cpu : The logical CPU whose thread group is being searched.
+ * @tg : The thread-group structure of the CPU node which @cpu belongs
+ * to.
+ *
+ * Returns the index to tg->thread_list that points to the start
+ * of the thread_group that @cpu belongs to.
+ *
+ * Returns -1 if cpu doesn't belong to any of the groups pointed to by
+ * tg->thread_list.
+ */
+static int get_cpu_thread_group_start(int cpu, struct thread_groups *tg)
+{
+ int hw_cpu_id = get_hard_smp_processor_id(cpu);
+ int i, j;
+
+ for (i = 0; i < tg->nr_groups; i++) {
+ int group_start = i * tg->threads_per_group;
+
+ for (j = 0; j < tg->threads_per_group; j++) {
+ int idx = group_start + j;
+
+ if (tg->thread_list[idx] == hw_cpu_id)
+ return group_start;
+ }
+ }
+
+ return -1;
+}
+
+static struct thread_groups *__init get_thread_groups(int cpu,
+ int group_property,
+ int *err)
+{
+ struct device_node *dn = of_get_cpu_node(cpu, NULL);
+ struct thread_groups_list *cpu_tgl = &tgl[cpu];
+ struct thread_groups *tg = NULL;
+ int i;
+ *err = 0;
+
+ if (!dn) {
+ *err = -ENODATA;
+ return NULL;
+ }
+
+ if (!cpu_tgl->nr_properties) {
+ *err = parse_thread_groups(dn, cpu_tgl);
+ if (*err)
+ goto out;
+ }
+
+ for (i = 0; i < cpu_tgl->nr_properties; i++) {
+ if (cpu_tgl->property_tgs[i].property == group_property) {
+ tg = &cpu_tgl->property_tgs[i];
+ break;
+ }
+ }
+
+ if (!tg)
+ *err = -EINVAL;
+out:
+ of_node_put(dn);
+ return tg;
+}
+
+static int __init update_mask_from_threadgroup(cpumask_var_t *mask, struct thread_groups *tg,
+ int cpu, int cpu_group_start)
+{
+ int first_thread = cpu_first_thread_sibling(cpu);
+ int i;
+
+ zalloc_cpumask_var_node(mask, GFP_KERNEL, cpu_to_node(cpu));
+
+ for (i = first_thread; i < first_thread + threads_per_core; i++) {
+ int i_group_start = get_cpu_thread_group_start(i, tg);
+
+ if (unlikely(i_group_start == -1)) {
+ WARN_ON_ONCE(1);
+ return -ENODATA;
+ }
+
+ if (i_group_start == cpu_group_start)
+ cpumask_set_cpu(i, *mask);
+ }
+
+ return 0;
+}
+
+static int __init init_thread_group_cache_map(int cpu, int cache_property)
+
+{
+ int cpu_group_start = -1, err = 0;
+ struct thread_groups *tg = NULL;
+ cpumask_var_t *mask = NULL;
+
+ if (cache_property != THREAD_GROUP_SHARE_L1 &&
+ cache_property != THREAD_GROUP_SHARE_L2_L3)
+ return -EINVAL;
+
+ tg = get_thread_groups(cpu, cache_property, &err);
+
+ if (!tg)
+ return err;
+
+ cpu_group_start = get_cpu_thread_group_start(cpu, tg);
+
+ if (unlikely(cpu_group_start == -1)) {
+ WARN_ON_ONCE(1);
+ return -ENODATA;
+ }
+
+ if (cache_property == THREAD_GROUP_SHARE_L1) {
+ mask = &per_cpu(thread_group_l1_cache_map, cpu);
+ update_mask_from_threadgroup(mask, tg, cpu, cpu_group_start);
+ }
+ else if (cache_property == THREAD_GROUP_SHARE_L2_L3) {
+ mask = &per_cpu(thread_group_l2_cache_map, cpu);
+ update_mask_from_threadgroup(mask, tg, cpu, cpu_group_start);
+ mask = &per_cpu(thread_group_l3_cache_map, cpu);
+ update_mask_from_threadgroup(mask, tg, cpu, cpu_group_start);
+ }
+
+
+ return 0;
+}
+
+static bool shared_caches;
+
+#ifdef CONFIG_SCHED_SMT
+/* cpumask of CPUs with asymmetric SMT dependency */
+static int powerpc_smt_flags(void)
+{
+ int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
+
+ if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
+ printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
+ flags |= SD_ASYM_PACKING;
+ }
+ return flags;
+}
+#endif
+
+/*
+ * P9 has a slightly odd architecture where pairs of cores share an L2 cache.
+ * This topology makes it *much* cheaper to migrate tasks between adjacent cores
+ * since the migrated task remains cache hot. We want to take advantage of this
+ * at the scheduler level so an extra topology level is required.
+ */
+static int powerpc_shared_cache_flags(void)
+{
+ return SD_SHARE_PKG_RESOURCES;
+}
+
+/*
+ * We can't just pass cpu_l2_cache_mask() directly because
+ * returns a non-const pointer and the compiler barfs on that.
+ */
+static const struct cpumask *shared_cache_mask(int cpu)
+{
+ return per_cpu(cpu_l2_cache_map, cpu);
+}
+
+#ifdef CONFIG_SCHED_SMT
+static const struct cpumask *smallcore_smt_mask(int cpu)
+{
+ return cpu_smallcore_mask(cpu);
+}
+#endif
+
+static struct cpumask *cpu_coregroup_mask(int cpu)
+{
+ return per_cpu(cpu_coregroup_map, cpu);
+}
+
+static bool has_coregroup_support(void)
+{
+ return coregroup_enabled;
+}
+
+static const struct cpumask *cpu_mc_mask(int cpu)
+{
+ return cpu_coregroup_mask(cpu);
+}
+
+static struct sched_domain_topology_level powerpc_topology[] = {
+#ifdef CONFIG_SCHED_SMT
+ { cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
+#endif
+ { shared_cache_mask, powerpc_shared_cache_flags, SD_INIT_NAME(CACHE) },
+ { cpu_mc_mask, SD_INIT_NAME(MC) },
+ { cpu_cpu_mask, SD_INIT_NAME(DIE) },
+ { NULL, },
+};
+
+static int __init init_big_cores(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ int err = init_thread_group_cache_map(cpu, THREAD_GROUP_SHARE_L1);
+
+ if (err)
+ return err;
+
+ zalloc_cpumask_var_node(&per_cpu(cpu_smallcore_map, cpu),
+ GFP_KERNEL,
+ cpu_to_node(cpu));
+ }
+
+ has_big_cores = true;
+
+ for_each_possible_cpu(cpu) {
+ int err = init_thread_group_cache_map(cpu, THREAD_GROUP_SHARE_L2_L3);
+
+ if (err)
+ return err;
+ }
+
+ thread_group_shares_l2 = true;
+ thread_group_shares_l3 = true;
+ pr_debug("L2/L3 cache only shared by the threads in the small core\n");
+
+ return 0;
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ unsigned int cpu;
+
+ DBG("smp_prepare_cpus\n");
+
+ /*
+ * setup_cpu may need to be called on the boot cpu. We haven't
+ * spun any cpus up but lets be paranoid.
+ */
+ BUG_ON(boot_cpuid != smp_processor_id());
+
+ /* Fixup boot cpu */
+ smp_store_cpu_info(boot_cpuid);
+ cpu_callin_map[boot_cpuid] = 1;
+
+ for_each_possible_cpu(cpu) {
+ zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
+ GFP_KERNEL, cpu_to_node(cpu));
+ zalloc_cpumask_var_node(&per_cpu(cpu_l2_cache_map, cpu),
+ GFP_KERNEL, cpu_to_node(cpu));
+ zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
+ GFP_KERNEL, cpu_to_node(cpu));
+ if (has_coregroup_support())
+ zalloc_cpumask_var_node(&per_cpu(cpu_coregroup_map, cpu),
+ GFP_KERNEL, cpu_to_node(cpu));
+
+#ifdef CONFIG_NUMA
+ /*
+ * numa_node_id() works after this.
+ */
+ if (cpu_present(cpu)) {
+ set_cpu_numa_node(cpu, numa_cpu_lookup_table[cpu]);
+ set_cpu_numa_mem(cpu,
+ local_memory_node(numa_cpu_lookup_table[cpu]));
+ }
+#endif
+ }
+
+ /* Init the cpumasks so the boot CPU is related to itself */
+ cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
+ cpumask_set_cpu(boot_cpuid, cpu_l2_cache_mask(boot_cpuid));
+ cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
+
+ if (has_coregroup_support())
+ cpumask_set_cpu(boot_cpuid, cpu_coregroup_mask(boot_cpuid));
+
+ init_big_cores();
+ if (has_big_cores) {
+ cpumask_set_cpu(boot_cpuid,
+ cpu_smallcore_mask(boot_cpuid));
+ }
+
+ if (cpu_to_chip_id(boot_cpuid) != -1) {
+ int idx = DIV_ROUND_UP(num_possible_cpus(), threads_per_core);
+
+ /*
+ * All threads of a core will all belong to the same core,
+ * chip_id_lookup_table will have one entry per core.
+ * Assumption: if boot_cpuid doesn't have a chip-id, then no
+ * other CPUs, will also not have chip-id.
+ */
+ chip_id_lookup_table = kcalloc(idx, sizeof(int), GFP_KERNEL);
+ if (chip_id_lookup_table)
+ memset(chip_id_lookup_table, -1, sizeof(int) * idx);
+ }
+
+ if (smp_ops && smp_ops->probe)
+ smp_ops->probe();
+}
+
+void smp_prepare_boot_cpu(void)
+{
+ BUG_ON(smp_processor_id() != boot_cpuid);
+#ifdef CONFIG_PPC64
+ paca_ptrs[boot_cpuid]->__current = current;
+#endif
+ set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
+ current_set[boot_cpuid] = current;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+int generic_cpu_disable(void)
+{
+ unsigned int cpu = smp_processor_id();
+
+ if (cpu == boot_cpuid)
+ return -EBUSY;
+
+ set_cpu_online(cpu, false);
+#ifdef CONFIG_PPC64
+ vdso_data->processorCount--;
+#endif
+ /* Update affinity of all IRQs previously aimed at this CPU */
+ irq_migrate_all_off_this_cpu();
+
+ /*
+ * Depending on the details of the interrupt controller, it's possible
+ * that one of the interrupts we just migrated away from this CPU is
+ * actually already pending on this CPU. If we leave it in that state
+ * the interrupt will never be EOI'ed, and will never fire again. So
+ * temporarily enable interrupts here, to allow any pending interrupt to
+ * be received (and EOI'ed), before we take this CPU offline.
+ */
+ local_irq_enable();
+ mdelay(1);
+ local_irq_disable();
+
+ return 0;
+}
+
+void generic_cpu_die(unsigned int cpu)
+{
+ int i;
+
+ for (i = 0; i < 100; i++) {
+ smp_rmb();
+ if (is_cpu_dead(cpu))
+ return;
+ msleep(100);
+ }
+ printk(KERN_ERR "CPU%d didn't die...\n", cpu);
+}
+
+void generic_set_cpu_dead(unsigned int cpu)
+{
+ per_cpu(cpu_state, cpu) = CPU_DEAD;
+}
+
+/*
+ * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
+ * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
+ * which makes the delay in generic_cpu_die() not happen.
+ */
+void generic_set_cpu_up(unsigned int cpu)
+{
+ per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
+}
+
+int generic_check_cpu_restart(unsigned int cpu)
+{
+ return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
+}
+
+int is_cpu_dead(unsigned int cpu)
+{
+ return per_cpu(cpu_state, cpu) == CPU_DEAD;
+}
+
+static bool secondaries_inhibited(void)
+{
+ return kvm_hv_mode_active();
+}
+
+#else /* HOTPLUG_CPU */
+
+#define secondaries_inhibited() 0
+
+#endif
+
+static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
+{
+#ifdef CONFIG_PPC64
+ paca_ptrs[cpu]->__current = idle;
+ paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) +
+ THREAD_SIZE - STACK_FRAME_OVERHEAD;
+#endif
+ task_thread_info(idle)->cpu = cpu;
+ secondary_current = current_set[cpu] = idle;
+}
+
+int __cpu_up(unsigned int cpu, struct task_struct *tidle)
+{
+ const unsigned long boot_spin_ms = 5 * MSEC_PER_SEC;
+ const bool booting = system_state < SYSTEM_RUNNING;
+ const unsigned long hp_spin_ms = 1;
+ unsigned long deadline;
+ int rc;
+ const unsigned long spin_wait_ms = booting ? boot_spin_ms : hp_spin_ms;
+
+ /*
+ * Don't allow secondary threads to come online if inhibited
+ */
+ if (threads_per_core > 1 && secondaries_inhibited() &&
+ cpu_thread_in_subcore(cpu))
+ return -EBUSY;
+
+ if (smp_ops == NULL ||
+ (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
+ return -EINVAL;
+
+ cpu_idle_thread_init(cpu, tidle);
+
+ /*
+ * The platform might need to allocate resources prior to bringing
+ * up the CPU
+ */
+ if (smp_ops->prepare_cpu) {
+ rc = smp_ops->prepare_cpu(cpu);
+ if (rc)
+ return rc;
+ }
+
+ /* Make sure callin-map entry is 0 (can be leftover a CPU
+ * hotplug
+ */
+ cpu_callin_map[cpu] = 0;
+
+ /* The information for processor bringup must
+ * be written out to main store before we release
+ * the processor.
+ */
+ smp_mb();
+
+ /* wake up cpus */
+ DBG("smp: kicking cpu %d\n", cpu);
+ rc = smp_ops->kick_cpu(cpu);
+ if (rc) {
+ pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
+ return rc;
+ }
+
+ /*
+ * At boot time, simply spin on the callin word until the
+ * deadline passes.
+ *
+ * At run time, spin for an optimistic amount of time to avoid
+ * sleeping in the common case.
+ */
+ deadline = jiffies + msecs_to_jiffies(spin_wait_ms);
+ spin_until_cond(cpu_callin_map[cpu] || time_is_before_jiffies(deadline));
+
+ if (!cpu_callin_map[cpu] && system_state >= SYSTEM_RUNNING) {
+ const unsigned long sleep_interval_us = 10 * USEC_PER_MSEC;
+ const unsigned long sleep_wait_ms = 100 * MSEC_PER_SEC;
+
+ deadline = jiffies + msecs_to_jiffies(sleep_wait_ms);
+ while (!cpu_callin_map[cpu] && time_is_after_jiffies(deadline))
+ fsleep(sleep_interval_us);
+ }
+
+ if (!cpu_callin_map[cpu]) {
+ printk(KERN_ERR "Processor %u is stuck.\n", cpu);
+ return -ENOENT;
+ }
+
+ DBG("Processor %u found.\n", cpu);
+
+ if (smp_ops->give_timebase)
+ smp_ops->give_timebase();
+
+ /* Wait until cpu puts itself in the online & active maps */
+ spin_until_cond(cpu_online(cpu));
+
+ return 0;
+}
+
+/* Return the value of the reg property corresponding to the given
+ * logical cpu.
+ */
+int cpu_to_core_id(int cpu)
+{
+ struct device_node *np;
+ int id = -1;
+
+ np = of_get_cpu_node(cpu, NULL);
+ if (!np)
+ goto out;
+
+ id = of_get_cpu_hwid(np, 0);
+out:
+ of_node_put(np);
+ return id;
+}
+EXPORT_SYMBOL_GPL(cpu_to_core_id);
+
+/* Helper routines for cpu to core mapping */
+int cpu_core_index_of_thread(int cpu)
+{
+ return cpu >> threads_shift;
+}
+EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
+
+int cpu_first_thread_of_core(int core)
+{
+ return core << threads_shift;
+}
+EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
+
+/* Must be called when no change can occur to cpu_present_mask,
+ * i.e. during cpu online or offline.
+ */
+static struct device_node *cpu_to_l2cache(int cpu)
+{
+ struct device_node *np;
+ struct device_node *cache;
+
+ if (!cpu_present(cpu))
+ return NULL;
+
+ np = of_get_cpu_node(cpu, NULL);
+ if (np == NULL)
+ return NULL;
+
+ cache = of_find_next_cache_node(np);
+
+ of_node_put(np);
+
+ return cache;
+}
+
+static bool update_mask_by_l2(int cpu, cpumask_var_t *mask)
+{
+ struct cpumask *(*submask_fn)(int) = cpu_sibling_mask;
+ struct device_node *l2_cache, *np;
+ int i;
+
+ if (has_big_cores)
+ submask_fn = cpu_smallcore_mask;
+
+ /*
+ * If the threads in a thread-group share L2 cache, then the
+ * L2-mask can be obtained from thread_group_l2_cache_map.
+ */
+ if (thread_group_shares_l2) {
+ cpumask_set_cpu(cpu, cpu_l2_cache_mask(cpu));
+
+ for_each_cpu(i, per_cpu(thread_group_l2_cache_map, cpu)) {
+ if (cpu_online(i))
+ set_cpus_related(i, cpu, cpu_l2_cache_mask);
+ }
+
+ /* Verify that L1-cache siblings are a subset of L2 cache-siblings */
+ if (!cpumask_equal(submask_fn(cpu), cpu_l2_cache_mask(cpu)) &&
+ !cpumask_subset(submask_fn(cpu), cpu_l2_cache_mask(cpu))) {
+ pr_warn_once("CPU %d : Inconsistent L1 and L2 cache siblings\n",
+ cpu);
+ }
+
+ return true;
+ }
+
+ l2_cache = cpu_to_l2cache(cpu);
+ if (!l2_cache || !*mask) {
+ /* Assume only core siblings share cache with this CPU */
+ for_each_cpu(i, cpu_sibling_mask(cpu))
+ set_cpus_related(cpu, i, cpu_l2_cache_mask);
+
+ return false;
+ }
+
+ cpumask_and(*mask, cpu_online_mask, cpu_cpu_mask(cpu));
+
+ /* Update l2-cache mask with all the CPUs that are part of submask */
+ or_cpumasks_related(cpu, cpu, submask_fn, cpu_l2_cache_mask);
+
+ /* Skip all CPUs already part of current CPU l2-cache mask */
+ cpumask_andnot(*mask, *mask, cpu_l2_cache_mask(cpu));
+
+ for_each_cpu(i, *mask) {
+ /*
+ * when updating the marks the current CPU has not been marked
+ * online, but we need to update the cache masks
+ */
+ np = cpu_to_l2cache(i);
+
+ /* Skip all CPUs already part of current CPU l2-cache */
+ if (np == l2_cache) {
+ or_cpumasks_related(cpu, i, submask_fn, cpu_l2_cache_mask);
+ cpumask_andnot(*mask, *mask, submask_fn(i));
+ } else {
+ cpumask_andnot(*mask, *mask, cpu_l2_cache_mask(i));
+ }
+
+ of_node_put(np);
+ }
+ of_node_put(l2_cache);
+
+ return true;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void remove_cpu_from_masks(int cpu)
+{
+ struct cpumask *(*mask_fn)(int) = cpu_sibling_mask;
+ int i;
+
+ unmap_cpu_from_node(cpu);
+
+ if (shared_caches)
+ mask_fn = cpu_l2_cache_mask;
+
+ for_each_cpu(i, mask_fn(cpu)) {
+ set_cpus_unrelated(cpu, i, cpu_l2_cache_mask);
+ set_cpus_unrelated(cpu, i, cpu_sibling_mask);
+ if (has_big_cores)
+ set_cpus_unrelated(cpu, i, cpu_smallcore_mask);
+ }
+
+ for_each_cpu(i, cpu_core_mask(cpu))
+ set_cpus_unrelated(cpu, i, cpu_core_mask);
+
+ if (has_coregroup_support()) {
+ for_each_cpu(i, cpu_coregroup_mask(cpu))
+ set_cpus_unrelated(cpu, i, cpu_coregroup_mask);
+ }
+}
+#endif
+
+static inline void add_cpu_to_smallcore_masks(int cpu)
+{
+ int i;
+
+ if (!has_big_cores)
+ return;
+
+ cpumask_set_cpu(cpu, cpu_smallcore_mask(cpu));
+
+ for_each_cpu(i, per_cpu(thread_group_l1_cache_map, cpu)) {
+ if (cpu_online(i))
+ set_cpus_related(i, cpu, cpu_smallcore_mask);
+ }
+}
+
+static void update_coregroup_mask(int cpu, cpumask_var_t *mask)
+{
+ struct cpumask *(*submask_fn)(int) = cpu_sibling_mask;
+ int coregroup_id = cpu_to_coregroup_id(cpu);
+ int i;
+
+ if (shared_caches)
+ submask_fn = cpu_l2_cache_mask;
+
+ if (!*mask) {
+ /* Assume only siblings are part of this CPU's coregroup */
+ for_each_cpu(i, submask_fn(cpu))
+ set_cpus_related(cpu, i, cpu_coregroup_mask);
+
+ return;
+ }
+
+ cpumask_and(*mask, cpu_online_mask, cpu_cpu_mask(cpu));
+
+ /* Update coregroup mask with all the CPUs that are part of submask */
+ or_cpumasks_related(cpu, cpu, submask_fn, cpu_coregroup_mask);
+
+ /* Skip all CPUs already part of coregroup mask */
+ cpumask_andnot(*mask, *mask, cpu_coregroup_mask(cpu));
+
+ for_each_cpu(i, *mask) {
+ /* Skip all CPUs not part of this coregroup */
+ if (coregroup_id == cpu_to_coregroup_id(i)) {
+ or_cpumasks_related(cpu, i, submask_fn, cpu_coregroup_mask);
+ cpumask_andnot(*mask, *mask, submask_fn(i));
+ } else {
+ cpumask_andnot(*mask, *mask, cpu_coregroup_mask(i));
+ }
+ }
+}
+
+static void add_cpu_to_masks(int cpu)
+{
+ struct cpumask *(*submask_fn)(int) = cpu_sibling_mask;
+ int first_thread = cpu_first_thread_sibling(cpu);
+ cpumask_var_t mask;
+ int chip_id = -1;
+ bool ret;
+ int i;
+
+ /*
+ * This CPU will not be in the online mask yet so we need to manually
+ * add it to it's own thread sibling mask.
+ */
+ map_cpu_to_node(cpu, cpu_to_node(cpu));
+ cpumask_set_cpu(cpu, cpu_sibling_mask(cpu));
+ cpumask_set_cpu(cpu, cpu_core_mask(cpu));
+
+ for (i = first_thread; i < first_thread + threads_per_core; i++)
+ if (cpu_online(i))
+ set_cpus_related(i, cpu, cpu_sibling_mask);
+
+ add_cpu_to_smallcore_masks(cpu);
+
+ /* In CPU-hotplug path, hence use GFP_ATOMIC */
+ ret = alloc_cpumask_var_node(&mask, GFP_ATOMIC, cpu_to_node(cpu));
+ update_mask_by_l2(cpu, &mask);
+
+ if (has_coregroup_support())
+ update_coregroup_mask(cpu, &mask);
+
+ if (chip_id_lookup_table && ret)
+ chip_id = cpu_to_chip_id(cpu);
+
+ if (shared_caches)
+ submask_fn = cpu_l2_cache_mask;
+
+ /* Update core_mask with all the CPUs that are part of submask */
+ or_cpumasks_related(cpu, cpu, submask_fn, cpu_core_mask);
+
+ /* Skip all CPUs already part of current CPU core mask */
+ cpumask_andnot(mask, cpu_online_mask, cpu_core_mask(cpu));
+
+ /* If chip_id is -1; limit the cpu_core_mask to within DIE*/
+ if (chip_id == -1)
+ cpumask_and(mask, mask, cpu_cpu_mask(cpu));
+
+ for_each_cpu(i, mask) {
+ if (chip_id == cpu_to_chip_id(i)) {
+ or_cpumasks_related(cpu, i, submask_fn, cpu_core_mask);
+ cpumask_andnot(mask, mask, submask_fn(i));
+ } else {
+ cpumask_andnot(mask, mask, cpu_core_mask(i));
+ }
+ }
+
+ free_cpumask_var(mask);
+}
+
+/* Activate a secondary processor. */
+void start_secondary(void *unused)
+{
+ unsigned int cpu = raw_smp_processor_id();
+
+ /* PPC64 calls setup_kup() in early_setup_secondary() */
+ if (IS_ENABLED(CONFIG_PPC32))
+ setup_kup();
+
+ mmgrab(&init_mm);
+ current->active_mm = &init_mm;
+
+ smp_store_cpu_info(cpu);
+ set_dec(tb_ticks_per_jiffy);
+ rcu_cpu_starting(cpu);
+ cpu_callin_map[cpu] = 1;
+
+ if (smp_ops->setup_cpu)
+ smp_ops->setup_cpu(cpu);
+ if (smp_ops->take_timebase)
+ smp_ops->take_timebase();
+
+ secondary_cpu_time_init();
+
+#ifdef CONFIG_PPC64
+ if (system_state == SYSTEM_RUNNING)
+ vdso_data->processorCount++;
+
+ vdso_getcpu_init();
+#endif
+ set_numa_node(numa_cpu_lookup_table[cpu]);
+ set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu]));
+
+ /* Update topology CPU masks */
+ add_cpu_to_masks(cpu);
+
+ /*
+ * Check for any shared caches. Note that this must be done on a
+ * per-core basis because one core in the pair might be disabled.
+ */
+ if (!shared_caches) {
+ struct cpumask *(*sibling_mask)(int) = cpu_sibling_mask;
+ struct cpumask *mask = cpu_l2_cache_mask(cpu);
+
+ if (has_big_cores)
+ sibling_mask = cpu_smallcore_mask;
+
+ if (cpumask_weight(mask) > cpumask_weight(sibling_mask(cpu)))
+ shared_caches = true;
+ }
+
+ smp_wmb();
+ notify_cpu_starting(cpu);
+ set_cpu_online(cpu, true);
+
+ boot_init_stack_canary();
+
+ local_irq_enable();
+
+ /* We can enable ftrace for secondary cpus now */
+ this_cpu_enable_ftrace();
+
+ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
+
+ BUG();
+}
+
+static void __init fixup_topology(void)
+{
+ int i;
+
+#ifdef CONFIG_SCHED_SMT
+ if (has_big_cores) {
+ pr_info("Big cores detected but using small core scheduling\n");
+ powerpc_topology[smt_idx].mask = smallcore_smt_mask;
+ }
+#endif
+
+ if (!has_coregroup_support())
+ powerpc_topology[mc_idx].mask = powerpc_topology[cache_idx].mask;
+
+ /*
+ * Try to consolidate topology levels here instead of
+ * allowing scheduler to degenerate.
+ * - Dont consolidate if masks are different.
+ * - Dont consolidate if sd_flags exists and are different.
+ */
+ for (i = 1; i <= die_idx; i++) {
+ if (powerpc_topology[i].mask != powerpc_topology[i - 1].mask)
+ continue;
+
+ if (powerpc_topology[i].sd_flags && powerpc_topology[i - 1].sd_flags &&
+ powerpc_topology[i].sd_flags != powerpc_topology[i - 1].sd_flags)
+ continue;
+
+ if (!powerpc_topology[i - 1].sd_flags)
+ powerpc_topology[i - 1].sd_flags = powerpc_topology[i].sd_flags;
+
+ powerpc_topology[i].mask = powerpc_topology[i + 1].mask;
+ powerpc_topology[i].sd_flags = powerpc_topology[i + 1].sd_flags;
+#ifdef CONFIG_SCHED_DEBUG
+ powerpc_topology[i].name = powerpc_topology[i + 1].name;
+#endif
+ }
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+ /*
+ * We are running pinned to the boot CPU, see rest_init().
+ */
+ if (smp_ops && smp_ops->setup_cpu)
+ smp_ops->setup_cpu(boot_cpuid);
+
+ if (smp_ops && smp_ops->bringup_done)
+ smp_ops->bringup_done();
+
+ dump_numa_cpu_topology();
+
+ fixup_topology();
+ set_sched_topology(powerpc_topology);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+int __cpu_disable(void)
+{
+ int cpu = smp_processor_id();
+ int err;
+
+ if (!smp_ops->cpu_disable)
+ return -ENOSYS;
+
+ this_cpu_disable_ftrace();
+
+ err = smp_ops->cpu_disable();
+ if (err)
+ return err;
+
+ /* Update sibling maps */
+ remove_cpu_from_masks(cpu);
+
+ return 0;
+}
+
+void __cpu_die(unsigned int cpu)
+{
+ if (smp_ops->cpu_die)
+ smp_ops->cpu_die(cpu);
+}
+
+void arch_cpu_idle_dead(void)
+{
+ /*
+ * Disable on the down path. This will be re-enabled by
+ * start_secondary() via start_secondary_resume() below
+ */
+ this_cpu_disable_ftrace();
+
+ if (smp_ops->cpu_offline_self)
+ smp_ops->cpu_offline_self();
+
+ /* If we return, we re-enter start_secondary */
+ start_secondary_resume();
+}
+
+#endif