Release 4.14 arch/powerpc/platforms/powernv/smp.c
/*
* SMP support for PowerNV machines.
*
* Copyright 2011 IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/sched/hotplug.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/cpu.h>
#include <asm/irq.h>
#include <asm/smp.h>
#include <asm/paca.h>
#include <asm/machdep.h>
#include <asm/cputable.h>
#include <asm/firmware.h>
#include <asm/vdso_datapage.h>
#include <asm/cputhreads.h>
#include <asm/xics.h>
#include <asm/xive.h>
#include <asm/opal.h>
#include <asm/runlatch.h>
#include <asm/code-patching.h>
#include <asm/dbell.h>
#include <asm/kvm_ppc.h>
#include <asm/ppc-opcode.h>
#include <asm/cpuidle.h>
#include "powernv.h"
#ifdef DEBUG
#include <asm/udbg.h>
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif
static void pnv_smp_setup_cpu(int cpu)
{
if (xive_enabled())
xive_smp_setup_cpu();
else if (cpu != boot_cpuid)
xics_setup_cpu();
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Benjamin Herrenschmidt | 27 | 100.00% | 2 | 100.00% |
| Total | 27 | 100.00% | 2 | 100.00% |
static int pnv_smp_kick_cpu(int nr)
{
unsigned int pcpu;
unsigned long start_here =
__pa(ppc_function_entry(generic_secondary_smp_init));
long rc;
uint8_t status;
if (nr < 0 || nr >= nr_cpu_ids)
return -EINVAL;
pcpu = get_hard_smp_processor_id(nr);
/*
* If we already started or OPAL is not supported, we just
* kick the CPU via the PACA
*/
if (paca[nr].cpu_start || !firmware_has_feature(FW_FEATURE_OPAL))
goto kick;
/*
* At this point, the CPU can either be spinning on the way in
* from kexec or be inside OPAL waiting to be started for the
* first time. OPAL v3 allows us to query OPAL to know if it
* has the CPUs, so we do that
*/
rc = opal_query_cpu_status(pcpu, &status);
if (rc != OPAL_SUCCESS) {
pr_warn("OPAL Error %ld querying CPU %d state\n", rc, nr);
return -ENODEV;
}
/*
* Already started, just kick it, probably coming from
* kexec and spinning
*/
if (status == OPAL_THREAD_STARTED)
goto kick;
/*
* Available/inactive, let's kick it
*/
if (status == OPAL_THREAD_INACTIVE) {
pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n", nr, pcpu);
rc = opal_start_cpu(pcpu, start_here);
if (rc != OPAL_SUCCESS) {
pr_warn("OPAL Error %ld starting CPU %d\n", rc, nr);
return -ENODEV;
}
} else {
/*
* An unavailable CPU (or any other unknown status)
* shouldn't be started. It should also
* not be in the possible map but currently it can
* happen
*/
pr_devel("OPAL: CPU %d (HW 0x%x) is unavailable"
" (status %d)...\n", nr, pcpu, status);
return -ENODEV;
}
kick:
return smp_generic_kick_cpu(nr);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Benjamin Herrenschmidt | 156 | 82.54% | 3 | 30.00% |
| Santosh Sivaraj | 15 | 7.94% | 3 | 30.00% |
| Stewart Smith | 8 | 4.23% | 1 | 10.00% |
| Paul Mackerras | 6 | 3.17% | 1 | 10.00% |
| Anton Blanchard | 4 | 2.12% | 2 | 20.00% |
| Total | 189 | 100.00% | 10 | 100.00% |
#ifdef CONFIG_HOTPLUG_CPU
static int pnv_smp_cpu_disable(void)
{
int cpu = smp_processor_id();
/* This is identical to pSeries... might consolidate by
* moving migrate_irqs_away to a ppc_md with default to
* the generic fixup_irqs. --BenH.
*/
set_cpu_online(cpu, false);
vdso_data->processorCount--;
if (cpu == boot_cpuid)
boot_cpuid = cpumask_any(cpu_online_mask);
if (xive_enabled())
xive_smp_disable_cpu();
else
xics_migrate_irqs_away();
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Benjamin Herrenschmidt | 55 | 100.00% | 2 | 100.00% |
| Total | 55 | 100.00% | 2 | 100.00% |
static void pnv_smp_cpu_kill_self(void)
{
unsigned int cpu;
unsigned long srr1, wmask;
/* Standard hot unplug procedure */
/*
* This hard disables local interurpts, ensuring we have no lazy
* irqs pending.
*/
WARN_ON(irqs_disabled());
hard_irq_disable();
WARN_ON(lazy_irq_pending());
idle_task_exit();
current->active_mm = NULL; /* for sanity */
cpu = smp_processor_id();
DBG("CPU%d offline\n", cpu);
generic_set_cpu_dead(cpu);
smp_wmb();
wmask = SRR1_WAKEMASK;
if (cpu_has_feature(CPU_FTR_ARCH_207S))
wmask = SRR1_WAKEMASK_P8;
while (!generic_check_cpu_restart(cpu)) {
/*
* Clear IPI flag, since we don't handle IPIs while
* offline, except for those when changing micro-threading
* mode, which are handled explicitly below, and those
* for coming online, which are handled via
* generic_check_cpu_restart() calls.
*/
kvmppc_set_host_ipi(cpu, 0);
srr1 = pnv_cpu_offline(cpu);
WARN_ON(lazy_irq_pending());
/*
* If the SRR1 value indicates that we woke up due to
* an external interrupt, then clear the interrupt.
* We clear the interrupt before checking for the
* reason, so as to avoid a race where we wake up for
* some other reason, find nothing and clear the interrupt
* just as some other cpu is sending us an interrupt.
* If we returned from power7_nap as a result of
* having finished executing in a KVM guest, then srr1
* contains 0.
*/
if (((srr1 & wmask) == SRR1_WAKEEE) ||
((srr1 & wmask) == SRR1_WAKEHVI)) {
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
if (xive_enabled())
xive_flush_interrupt();
else
icp_opal_flush_interrupt();
} else
icp_native_flush_interrupt();
} else if ((srr1 & wmask) == SRR1_WAKEHDBELL) {
unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER);
asm volatile(PPC_MSGCLR(%0) : : "r" (msg));
}
smp_mb();
if (cpu_core_split_required())
continue;
if (srr1 && !generic_check_cpu_restart(cpu))
DBG("CPU%d Unexpected exit while offline srr1=%lx!\n",
cpu, srr1);
}
DBG("CPU%d coming online...\n", cpu);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Benjamin Herrenschmidt | 107 | 48.42% | 3 | 27.27% |
| Paul Mackerras | 77 | 34.84% | 3 | 27.27% |
| Nicholas Piggin | 23 | 10.41% | 1 | 9.09% |
| Michael Ellerman | 9 | 4.07% | 2 | 18.18% |
| Shreyas B. Prabhu | 3 | 1.36% | 1 | 9.09% |
| Gautham R. Shenoy | 2 | 0.90% | 1 | 9.09% |
| Total | 221 | 100.00% | 11 | 100.00% |
#endif /* CONFIG_HOTPLUG_CPU */
static int pnv_cpu_bootable(unsigned int nr)
{
/*
* Starting with POWER8, the subcore logic relies on all threads of a
* core being booted so that they can participate in split mode
* switches. So on those machines we ignore the smt_enabled_at_boot
* setting (smt-enabled on the kernel command line).
*/
if (cpu_has_feature(CPU_FTR_ARCH_207S))
return 1;
return smp_generic_cpu_bootable(nr);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Greg Kurz | 27 | 100.00% | 1 | 100.00% |
| Total | 27 | 100.00% | 1 | 100.00% |
static int pnv_smp_prepare_cpu(int cpu)
{
if (xive_enabled())
return xive_smp_prepare_cpu(cpu);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Benjamin Herrenschmidt | 23 | 100.00% | 1 | 100.00% |
| Total | 23 | 100.00% | 1 | 100.00% |
/* Cause IPI as setup by the interrupt controller (xics or xive) */
static void (*ic_cause_ipi)(int cpu);
static void pnv_cause_ipi(int cpu)
{
if (doorbell_try_core_ipi(cpu))
return;
ic_cause_ipi(cpu);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Nicholas Piggin | 21 | 95.45% | 1 | 50.00% |
| Michael Ellerman | 1 | 4.55% | 1 | 50.00% |
| Total | 22 | 100.00% | 2 | 100.00% |
static void pnv_p9_dd1_cause_ipi(int cpu)
{
int this_cpu = get_cpu();
/*
* POWER9 DD1 has a global addressed msgsnd, but for now we restrict
* IPIs to same core, because it requires additional synchronization
* for inter-core doorbells which we do not implement.
*/
if (cpumask_test_cpu(cpu, cpu_sibling_mask(this_cpu)))
doorbell_global_ipi(cpu);
else
ic_cause_ipi(cpu);
put_cpu();
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Nicholas Piggin | 41 | 97.62% | 1 | 50.00% |
| Michael Ellerman | 1 | 2.38% | 1 | 50.00% |
| Total | 42 | 100.00% | 2 | 100.00% |
static void __init pnv_smp_probe(void)
{
if (xive_enabled())
xive_smp_probe();
else
xics_smp_probe();
if (cpu_has_feature(CPU_FTR_DBELL)) {
ic_cause_ipi = smp_ops->cause_ipi;
WARN_ON(!ic_cause_ipi);
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
if (cpu_has_feature(CPU_FTR_POWER9_DD1))
smp_ops->cause_ipi = pnv_p9_dd1_cause_ipi;
else
smp_ops->cause_ipi = doorbell_global_ipi;
} else {
smp_ops->cause_ipi = pnv_cause_ipi;
}
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Nicholas Piggin | 47 | 58.75% | 2 | 50.00% |
| Benjamin Herrenschmidt | 21 | 26.25% | 1 | 25.00% |
| Michael Ellerman | 12 | 15.00% | 1 | 25.00% |
| Total | 80 | 100.00% | 4 | 100.00% |
static struct smp_ops_t pnv_smp_ops = {
.message_pass = NULL, /* Use smp_muxed_ipi_message_pass */
.cause_ipi = NULL, /* Filled at runtime by pnv_smp_probe() */
.cause_nmi_ipi = NULL,
.probe = pnv_smp_probe,
.prepare_cpu = pnv_smp_prepare_cpu,
.kick_cpu = pnv_smp_kick_cpu,
.setup_cpu = pnv_smp_setup_cpu,
.cpu_bootable = pnv_cpu_bootable,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_disable = pnv_smp_cpu_disable,
.cpu_die = generic_cpu_die,
#endif /* CONFIG_HOTPLUG_CPU */
};
/* This is called very early during platform setup_arch */
void __init pnv_smp_init(void)
{
smp_ops = &pnv_smp_ops;
#ifdef CONFIG_HOTPLUG_CPU
ppc_md.cpu_die = pnv_smp_cpu_kill_self;
#endif
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Benjamin Herrenschmidt | 24 | 100.00% | 2 | 100.00% |
| Total | 24 | 100.00% | 2 | 100.00% |
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Benjamin Herrenschmidt | 566 | 62.54% | 7 | 23.33% |
| Nicholas Piggin | 140 | 15.47% | 4 | 13.33% |
| Paul Mackerras | 89 | 9.83% | 4 | 13.33% |
| Michael Ellerman | 35 | 3.87% | 3 | 10.00% |
| Greg Kurz | 28 | 3.09% | 1 | 3.33% |
| Santosh Sivaraj | 15 | 1.66% | 3 | 10.00% |
| Stewart Smith | 8 | 0.88% | 1 | 3.33% |
| Anton Blanchard | 7 | 0.77% | 2 | 6.67% |
| Gautham R. Shenoy | 5 | 0.55% | 1 | 3.33% |
| Michael Neuling | 3 | 0.33% | 1 | 3.33% |
| Ingo Molnar | 3 | 0.33% | 1 | 3.33% |
| Preeti U. Murthy | 3 | 0.33% | 1 | 3.33% |
| Shreyas B. Prabhu | 3 | 0.33% | 1 | 3.33% |
| Total | 905 | 100.00% | 30 | 100.00% |
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.