1 files changed, 451 insertions, 0 deletions

diff --git a/arch/ppc64/kernel/pSeries_smp.c b/arch/ppc64/kernel/pSeries_smp.c
new file mode 100644
index 000000000000..c60d8cb2b84d
--- /dev/null
+++ b/arch/ppc64/kernel/pSeries_smp.c
@@ -0,0 +1,451 @@
+/*
+ * SMP support for pSeries machines.
+ *
+ * Dave Engebretsen, Peter Bergner, and
+ * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
+ *
+ * Plus various changes from other IBM teams...
+ *
+ *      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.
+ */
+
+#undef DEBUG
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.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/sysdev.h>
+#include <linux/cpu.h>
+
+#include <asm/ptrace.h>
+#include <asm/atomic.h>
+#include <asm/irq.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/smp.h>
+#include <asm/paca.h>
+#include <asm/time.h>
+#include <asm/machdep.h>
+#include <asm/xics.h>
+#include <asm/cputable.h>
+#include <asm/system.h>
+#include <asm/rtas.h>
+#include <asm/plpar_wrappers.h>
+#include <asm/pSeries_reconfig.h>
+
+#include "mpic.h"
+
+#ifdef DEBUG
+#define DBG(fmt...) udbg_printf(fmt)
+#else
+#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
+ *      1       - stop-self is in progress
+ *      2       - The processor is not in the RTAS stopped state
+ *      -1      - Hardware Error
+ *      -2      - Hardware Busy, Try again later.
+ */
+static int query_cpu_stopped(unsigned int pcpu)
+{
+        int cpu_status;
+        int status, qcss_tok;
+
+        qcss_tok = rtas_token("query-cpu-stopped-state");
+        if (qcss_tok == RTAS_UNKNOWN_SERVICE)
+                return -1;
+        status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu);
+        if (status != 0) {
+                printk(KERN_ERR
+                       "RTAS query-cpu-stopped-state failed: %i\n", status);
+                return status;
+        }
+
+        return cpu_status;
+}
+
+int pSeries_cpu_disable(void)
+{
+        systemcfg->processorCount--;
+
+        /*fix boot_cpuid here*/
+        if (smp_processor_id() == boot_cpuid)
+                boot_cpuid = any_online_cpu(cpu_online_map);
+
+        /* FIXME: abstract this to not be platform specific later on */
+        xics_migrate_irqs_away();
+        return 0;
+}
+
+void pSeries_cpu_die(unsigned int cpu)
+{
+        int tries;
+        int cpu_status;
+        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;
+                msleep(200);
+        }
+        if (cpu_status != 0) {
+                printk("Querying DEAD? cpu %i (%i) shows %i\n",
+                       cpu, pcpu, cpu_status);
+        }
+
+        /* Isolation and deallocation are definatly done by
+         * drslot_chrp_cpu.  If they were not they would be
+         * done here.  Change isolate state to Isolate and
+         * change allocation-state to Unusable.
+         */
+        paca[cpu].cpu_start = 0;
+}
+
+/*
+ * 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 int pSeries_add_processor(struct device_node *np)
+{
+        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;
+
+        nthreads = len / sizeof(u32);
+        for (i = 0; i < nthreads; i++)
+                cpu_set(i, tmp);
+
+        lock_cpu_hotplug();
+
+        BUG_ON(!cpus_subset(cpu_present_map, cpu_possible_map));
+
+        /* 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.
+                 */
+                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;
+}
+
+/*
+ * 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;
+
+        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]);
+        }
+        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 for primary threads which were
+ * started from Open Firmware.  For anything else, call RTAS with the
+ * appropriate start location.
+ *
+ * Returns:
+ *      0       - failure
+ *      1       - success
+ */
+static inline int __devinit smp_startup_cpu(unsigned int lcpu)
+{
+        int status;
+        unsigned long start_here = __pa((u32)*((unsigned long *)
+                                               pSeries_secondary_smp_init));
+        unsigned int pcpu;
+
+        if (cpu_isset(lcpu, of_spin_map))
+                /* Already started by OF and sitting in spin loop */
+                return 1;
+
+        pcpu = get_hard_smp_processor_id(lcpu);
+
+        /* Fixup atomic count: it exited inside IRQ handler. */
+        paca[lcpu].__current->thread_info->preempt_count        = 0;
+
+        status = rtas_call(rtas_token("start-cpu"), 3, 1, NULL,
+                           pcpu, start_here, lcpu);
+        if (status != 0) {
+                printk(KERN_ERR "start-cpu failed: %i\n", status);
+                return 0;
+        }
+        return 1;
+}
+
+static inline void smp_xics_do_message(int cpu, int msg)
+{
+        set_bit(msg, &xics_ipi_message[cpu].value);
+        mb();
+        xics_cause_IPI(cpu);
+}
+
+static void smp_xics_message_pass(int target, int msg)
+{
+        unsigned int i;
+
+        if (target < NR_CPUS) {
+                smp_xics_do_message(target, msg);
+        } else {
+                for_each_online_cpu(i) {
+                        if (target == MSG_ALL_BUT_SELF
+                            && i == smp_processor_id())
+                                continue;
+                        smp_xics_do_message(i, msg);
+                }
+        }
+}
+
+static int __init smp_xics_probe(void)
+{
+        xics_request_IPIs();
+
+        return cpus_weight(cpu_possible_map);
+}
+
+static void __devinit smp_xics_setup_cpu(int cpu)
+{
+        if (cpu != boot_cpuid)
+                xics_setup_cpu();
+
+        if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR)
+                vpa_init(cpu);
+
+        cpu_clear(cpu, of_spin_map);
+
+        /*
+         * 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);
+}
+
+static DEFINE_SPINLOCK(timebase_lock);
+static unsigned long timebase = 0;
+
+static void __devinit pSeries_give_timebase(void)
+{
+        spin_lock(&timebase_lock);
+        rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
+        timebase = get_tb();
+        spin_unlock(&timebase_lock);
+
+        while (timebase)
+                barrier();
+        rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
+}
+
+static void __devinit pSeries_take_timebase(void)
+{
+        while (!timebase)
+                barrier();
+        spin_lock(&timebase_lock);
+        set_tb(timebase >> 32, timebase & 0xffffffff);
+        timebase = 0;
+        spin_unlock(&timebase_lock);
+}
+
+static void __devinit smp_pSeries_kick_cpu(int nr)
+{
+        BUG_ON(nr < 0 || nr >= NR_CPUS);
+
+        if (!smp_startup_cpu(nr))
+                return;
+
+        /*
+         * 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
+         */
+        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,
+        .kick_cpu       = smp_pSeries_kick_cpu,
+        .setup_cpu      = smp_mpic_setup_cpu,
+};
+
+static struct smp_ops_t pSeries_xics_smp_ops = {
+        .message_pass   = smp_xics_message_pass,
+        .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 i;
+
+        DBG(" -> smp_init_pSeries()\n");
+
+        if (ppc64_interrupt_controller == IC_OPEN_PIC)
+                smp_ops = &pSeries_mpic_smp_ops;
+        else
+                smp_ops = &pSeries_xics_smp_ops;
+
+#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
+
+        /* 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) {
+                smp_ops->give_timebase = pSeries_give_timebase;
+                smp_ops->take_timebase = pSeries_take_timebase;
+        }
+
+        DBG(" <- smp_init_pSeries()\n");
+}
+