aboutsummaryrefslogtreecommitdiff
path: root/arch/parisc/kernel/smp.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/parisc/kernel/smp.c')
-rw-r--r--arch/parisc/kernel/smp.c723
1 files changed, 723 insertions, 0 deletions
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
new file mode 100644
index 00000000000..bcc7e83f514
--- /dev/null
+++ b/arch/parisc/kernel/smp.c
@@ -0,0 +1,723 @@
+/*
+** SMP Support
+**
+** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
+** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
+** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>
+**
+** Lots of stuff stolen from arch/alpha/kernel/smp.c
+** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
+**
+** Thanks to John Curry and Ullas Ponnadi. I learned alot from their work.
+** -grant (1/12/2001)
+**
+** 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 ENTRY_SYS_CPUS /* syscall support for iCOD-like functionality */
+
+#include <linux/autoconf.h>
+
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/smp.h>
+#include <linux/kernel_stat.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+
+#include <asm/system.h>
+#include <asm/atomic.h>
+#include <asm/current.h>
+#include <asm/delay.h>
+#include <asm/pgalloc.h> /* for flush_tlb_all() proto/macro */
+
+#include <asm/io.h>
+#include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
+#include <asm/mmu_context.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/processor.h>
+#include <asm/ptrace.h>
+#include <asm/unistd.h>
+#include <asm/cacheflush.h>
+
+#define kDEBUG 0
+
+DEFINE_SPINLOCK(smp_lock);
+
+volatile struct task_struct *smp_init_current_idle_task;
+
+static volatile int cpu_now_booting = 0; /* track which CPU is booting */
+
+static int parisc_max_cpus = 1;
+
+/* online cpus are ones that we've managed to bring up completely
+ * possible cpus are all valid cpu
+ * present cpus are all detected cpu
+ *
+ * On startup we bring up the "possible" cpus. Since we discover
+ * CPUs later, we add them as hotplug, so the possible cpu mask is
+ * empty in the beginning.
+ */
+
+cpumask_t cpu_online_map = CPU_MASK_NONE; /* Bitmap of online CPUs */
+cpumask_t cpu_possible_map = CPU_MASK_ALL; /* Bitmap of Present CPUs */
+
+EXPORT_SYMBOL(cpu_online_map);
+EXPORT_SYMBOL(cpu_possible_map);
+
+
+struct smp_call_struct {
+ void (*func) (void *info);
+ void *info;
+ long wait;
+ atomic_t unstarted_count;
+ atomic_t unfinished_count;
+};
+static volatile struct smp_call_struct *smp_call_function_data;
+
+enum ipi_message_type {
+ IPI_NOP=0,
+ IPI_RESCHEDULE=1,
+ IPI_CALL_FUNC,
+ IPI_CPU_START,
+ IPI_CPU_STOP,
+ IPI_CPU_TEST
+};
+
+
+/********** SMP inter processor interrupt and communication routines */
+
+#undef PER_CPU_IRQ_REGION
+#ifdef PER_CPU_IRQ_REGION
+/* XXX REVISIT Ignore for now.
+** *May* need this "hook" to register IPI handler
+** once we have perCPU ExtIntr switch tables.
+*/
+static void
+ipi_init(int cpuid)
+{
+
+ /* If CPU is present ... */
+#ifdef ENTRY_SYS_CPUS
+ /* *and* running (not stopped) ... */
+#error iCOD support wants state checked here.
+#endif
+
+#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
+
+ if(cpu_online(cpuid) )
+ {
+ switch_to_idle_task(current);
+ }
+
+ return;
+}
+#endif
+
+
+/*
+** Yoink this CPU from the runnable list...
+**
+*/
+static void
+halt_processor(void)
+{
+#ifdef ENTRY_SYS_CPUS
+#error halt_processor() needs rework
+/*
+** o migrate I/O interrupts off this CPU.
+** o leave IPI enabled - __cli() will disable IPI.
+** o leave CPU in online map - just change the state
+*/
+ cpu_data[this_cpu].state = STATE_STOPPED;
+ mark_bh(IPI_BH);
+#else
+ /* REVISIT : redirect I/O Interrupts to another CPU? */
+ /* REVISIT : does PM *know* this CPU isn't available? */
+ cpu_clear(smp_processor_id(), cpu_online_map);
+ local_irq_disable();
+ for (;;)
+ ;
+#endif
+}
+
+
+irqreturn_t
+ipi_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ int this_cpu = smp_processor_id();
+ struct cpuinfo_parisc *p = &cpu_data[this_cpu];
+ unsigned long ops;
+ unsigned long flags;
+
+ /* Count this now; we may make a call that never returns. */
+ p->ipi_count++;
+
+ mb(); /* Order interrupt and bit testing. */
+
+ for (;;) {
+ spin_lock_irqsave(&(p->lock),flags);
+ ops = p->pending_ipi;
+ p->pending_ipi = 0;
+ spin_unlock_irqrestore(&(p->lock),flags);
+
+ mb(); /* Order bit clearing and data access. */
+
+ if (!ops)
+ break;
+
+ while (ops) {
+ unsigned long which = ffz(~ops);
+
+ switch (which) {
+ case IPI_RESCHEDULE:
+#if (kDEBUG>=100)
+ printk(KERN_DEBUG "CPU%d IPI_RESCHEDULE\n",this_cpu);
+#endif /* kDEBUG */
+ ops &= ~(1 << IPI_RESCHEDULE);
+ /*
+ * Reschedule callback. Everything to be
+ * done is done by the interrupt return path.
+ */
+ break;
+
+ case IPI_CALL_FUNC:
+#if (kDEBUG>=100)
+ printk(KERN_DEBUG "CPU%d IPI_CALL_FUNC\n",this_cpu);
+#endif /* kDEBUG */
+ ops &= ~(1 << IPI_CALL_FUNC);
+ {
+ volatile struct smp_call_struct *data;
+ void (*func)(void *info);
+ void *info;
+ int wait;
+
+ data = smp_call_function_data;
+ func = data->func;
+ info = data->info;
+ wait = data->wait;
+
+ mb();
+ atomic_dec ((atomic_t *)&data->unstarted_count);
+
+ /* At this point, *data can't
+ * be relied upon.
+ */
+
+ (*func)(info);
+
+ /* Notify the sending CPU that the
+ * task is done.
+ */
+ mb();
+ if (wait)
+ atomic_dec ((atomic_t *)&data->unfinished_count);
+ }
+ break;
+
+ case IPI_CPU_START:
+#if (kDEBUG>=100)
+ printk(KERN_DEBUG "CPU%d IPI_CPU_START\n",this_cpu);
+#endif /* kDEBUG */
+ ops &= ~(1 << IPI_CPU_START);
+#ifdef ENTRY_SYS_CPUS
+ p->state = STATE_RUNNING;
+#endif
+ break;
+
+ case IPI_CPU_STOP:
+#if (kDEBUG>=100)
+ printk(KERN_DEBUG "CPU%d IPI_CPU_STOP\n",this_cpu);
+#endif /* kDEBUG */
+ ops &= ~(1 << IPI_CPU_STOP);
+#ifdef ENTRY_SYS_CPUS
+#else
+ halt_processor();
+#endif
+ break;
+
+ case IPI_CPU_TEST:
+#if (kDEBUG>=100)
+ printk(KERN_DEBUG "CPU%d is alive!\n",this_cpu);
+#endif /* kDEBUG */
+ ops &= ~(1 << IPI_CPU_TEST);
+ break;
+
+ default:
+ printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
+ this_cpu, which);
+ ops &= ~(1 << which);
+ return IRQ_NONE;
+ } /* Switch */
+ } /* while (ops) */
+ }
+ return IRQ_HANDLED;
+}
+
+
+static inline void
+ipi_send(int cpu, enum ipi_message_type op)
+{
+ struct cpuinfo_parisc *p = &cpu_data[cpu];
+ unsigned long flags;
+
+ spin_lock_irqsave(&(p->lock),flags);
+ p->pending_ipi |= 1 << op;
+ gsc_writel(IPI_IRQ - CPU_IRQ_BASE, cpu_data[cpu].hpa);
+ spin_unlock_irqrestore(&(p->lock),flags);
+}
+
+
+static inline void
+send_IPI_single(int dest_cpu, enum ipi_message_type op)
+{
+ if (dest_cpu == NO_PROC_ID) {
+ BUG();
+ return;
+ }
+
+ ipi_send(dest_cpu, op);
+}
+
+static inline void
+send_IPI_allbutself(enum ipi_message_type op)
+{
+ int i;
+
+ for (i = 0; i < NR_CPUS; i++) {
+ if (cpu_online(i) && i != smp_processor_id())
+ send_IPI_single(i, op);
+ }
+}
+
+
+inline void
+smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
+
+static inline void
+smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START); }
+
+void
+smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
+
+
+/**
+ * Run a function on all other CPUs.
+ * <func> The function to run. This must be fast and non-blocking.
+ * <info> An arbitrary pointer to pass to the function.
+ * <retry> If true, keep retrying until ready.
+ * <wait> If true, wait until function has completed on other CPUs.
+ * [RETURNS] 0 on success, else a negative status code.
+ *
+ * Does not return until remote CPUs are nearly ready to execute <func>
+ * or have executed.
+ */
+
+int
+smp_call_function (void (*func) (void *info), void *info, int retry, int wait)
+{
+ struct smp_call_struct data;
+ unsigned long timeout;
+ static DEFINE_SPINLOCK(lock);
+ int retries = 0;
+
+ if (num_online_cpus() < 2)
+ return 0;
+
+ /* Can deadlock when called with interrupts disabled */
+ WARN_ON(irqs_disabled());
+
+ data.func = func;
+ data.info = info;
+ data.wait = wait;
+ atomic_set(&data.unstarted_count, num_online_cpus() - 1);
+ atomic_set(&data.unfinished_count, num_online_cpus() - 1);
+
+ if (retry) {
+ spin_lock (&lock);
+ while (smp_call_function_data != 0)
+ barrier();
+ }
+ else {
+ spin_lock (&lock);
+ if (smp_call_function_data) {
+ spin_unlock (&lock);
+ return -EBUSY;
+ }
+ }
+
+ smp_call_function_data = &data;
+ spin_unlock (&lock);
+
+ /* Send a message to all other CPUs and wait for them to respond */
+ send_IPI_allbutself(IPI_CALL_FUNC);
+
+ retry:
+ /* Wait for response */
+ timeout = jiffies + HZ;
+ while ( (atomic_read (&data.unstarted_count) > 0) &&
+ time_before (jiffies, timeout) )
+ barrier ();
+
+ if (atomic_read (&data.unstarted_count) > 0) {
+ printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d), try %d\n",
+ smp_processor_id(), ++retries);
+ goto retry;
+ }
+ /* We either got one or timed out. Release the lock */
+
+ mb();
+ smp_call_function_data = NULL;
+
+ while (wait && atomic_read (&data.unfinished_count) > 0)
+ barrier ();
+
+ return 0;
+}
+
+EXPORT_SYMBOL(smp_call_function);
+
+/*
+ * Flush all other CPU's tlb and then mine. Do this with on_each_cpu()
+ * as we want to ensure all TLB's flushed before proceeding.
+ */
+
+extern void flush_tlb_all_local(void);
+
+void
+smp_flush_tlb_all(void)
+{
+ on_each_cpu((void (*)(void *))flush_tlb_all_local, NULL, 1, 1);
+}
+
+
+void
+smp_do_timer(struct pt_regs *regs)
+{
+ int cpu = smp_processor_id();
+ struct cpuinfo_parisc *data = &cpu_data[cpu];
+
+ if (!--data->prof_counter) {
+ data->prof_counter = data->prof_multiplier;
+ update_process_times(user_mode(regs));
+ }
+}
+
+/*
+ * Called by secondaries to update state and initialize CPU registers.
+ */
+static void __init
+smp_cpu_init(int cpunum)
+{
+ extern int init_per_cpu(int); /* arch/parisc/kernel/setup.c */
+ extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
+
+ /* Set modes and Enable floating point coprocessor */
+ (void) init_per_cpu(cpunum);
+
+ disable_sr_hashing();
+
+ mb();
+
+ /* Well, support 2.4 linux scheme as well. */
+ if (cpu_test_and_set(cpunum, cpu_online_map))
+ {
+ extern void machine_halt(void); /* arch/parisc.../process.c */
+
+ printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
+ machine_halt();
+ }
+
+ /* Initialise the idle task for this CPU */
+ atomic_inc(&init_mm.mm_count);
+ current->active_mm = &init_mm;
+ if(current->mm)
+ BUG();
+ enter_lazy_tlb(&init_mm, current);
+
+ init_IRQ(); /* make sure no IRQ's are enabled or pending */
+}
+
+
+/*
+ * Slaves start using C here. Indirectly called from smp_slave_stext.
+ * Do what start_kernel() and main() do for boot strap processor (aka monarch)
+ */
+void __init smp_callin(void)
+{
+ int slave_id = cpu_now_booting;
+#if 0
+ void *istack;
+#endif
+
+ smp_cpu_init(slave_id);
+
+#if 0 /* NOT WORKING YET - see entry.S */
+ istack = (void *)__get_free_pages(GFP_KERNEL,ISTACK_ORDER);
+ if (istack == NULL) {
+ printk(KERN_CRIT "Failed to allocate interrupt stack for cpu %d\n",slave_id);
+ BUG();
+ }
+ mtctl(istack,31);
+#endif
+
+ flush_cache_all_local(); /* start with known state */
+ flush_tlb_all_local();
+
+ local_irq_enable(); /* Interrupts have been off until now */
+
+ cpu_idle(); /* Wait for timer to schedule some work */
+
+ /* NOTREACHED */
+ panic("smp_callin() AAAAaaaaahhhh....\n");
+}
+
+/*
+ * Bring one cpu online.
+ */
+int __init smp_boot_one_cpu(int cpuid)
+{
+ struct task_struct *idle;
+ long timeout;
+
+ /*
+ * Create an idle task for this CPU. Note the address wed* give
+ * to kernel_thread is irrelevant -- it's going to start
+ * where OS_BOOT_RENDEVZ vector in SAL says to start. But
+ * this gets all the other task-y sort of data structures set
+ * up like we wish. We need to pull the just created idle task
+ * off the run queue and stuff it into the init_tasks[] array.
+ * Sheesh . . .
+ */
+
+ idle = fork_idle(cpuid);
+ if (IS_ERR(idle))
+ panic("SMP: fork failed for CPU:%d", cpuid);
+
+ idle->thread_info->cpu = cpuid;
+
+ /* Let _start know what logical CPU we're booting
+ ** (offset into init_tasks[],cpu_data[])
+ */
+ cpu_now_booting = cpuid;
+
+ /*
+ ** boot strap code needs to know the task address since
+ ** it also contains the process stack.
+ */
+ smp_init_current_idle_task = idle ;
+ mb();
+
+ printk("Releasing cpu %d now, hpa=%lx\n", cpuid, cpu_data[cpuid].hpa);
+
+ /*
+ ** This gets PDC to release the CPU from a very tight loop.
+ **
+ ** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
+ ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
+ ** is executed after receiving the rendezvous signal (an interrupt to
+ ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
+ ** contents of memory are valid."
+ */
+ gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, cpu_data[cpuid].hpa);
+ mb();
+
+ /*
+ * OK, wait a bit for that CPU to finish staggering about.
+ * Slave will set a bit when it reaches smp_cpu_init().
+ * Once the "monarch CPU" sees the bit change, it can move on.
+ */
+ for (timeout = 0; timeout < 10000; timeout++) {
+ if(cpu_online(cpuid)) {
+ /* Which implies Slave has started up */
+ cpu_now_booting = 0;
+ smp_init_current_idle_task = NULL;
+ goto alive ;
+ }
+ udelay(100);
+ barrier();
+ }
+
+ put_task_struct(idle);
+ idle = NULL;
+
+ printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
+ return -1;
+
+alive:
+ /* Remember the Slave data */
+#if (kDEBUG>=100)
+ printk(KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
+ cpuid, timeout * 100);
+#endif /* kDEBUG */
+#ifdef ENTRY_SYS_CPUS
+ cpu_data[cpuid].state = STATE_RUNNING;
+#endif
+ return 0;
+}
+
+void __devinit smp_prepare_boot_cpu(void)
+{
+ int bootstrap_processor=cpu_data[0].cpuid; /* CPU ID of BSP */
+
+#ifdef ENTRY_SYS_CPUS
+ cpu_data[0].state = STATE_RUNNING;
+#endif
+
+ /* Setup BSP mappings */
+ printk("SMP: bootstrap CPU ID is %d\n",bootstrap_processor);
+
+ cpu_set(bootstrap_processor, cpu_online_map);
+ cpu_set(bootstrap_processor, cpu_present_map);
+}
+
+
+
+/*
+** inventory.c:do_inventory() hasn't yet been run and thus we
+** don't 'discover' the additional CPU's until later.
+*/
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+ cpus_clear(cpu_present_map);
+ cpu_set(0, cpu_present_map);
+
+ parisc_max_cpus = max_cpus;
+ if (!max_cpus)
+ printk(KERN_INFO "SMP mode deactivated.\n");
+}
+
+
+void smp_cpus_done(unsigned int cpu_max)
+{
+ return;
+}
+
+
+int __devinit __cpu_up(unsigned int cpu)
+{
+ if (cpu != 0 && cpu < parisc_max_cpus)
+ smp_boot_one_cpu(cpu);
+
+ return cpu_online(cpu) ? 0 : -ENOSYS;
+}
+
+
+
+#ifdef ENTRY_SYS_CPUS
+/* Code goes along with:
+** entry.s: ENTRY_NAME(sys_cpus) / * 215, for cpu stat * /
+*/
+int sys_cpus(int argc, char **argv)
+{
+ int i,j=0;
+ extern int current_pid(int cpu);
+
+ if( argc > 2 ) {
+ printk("sys_cpus:Only one argument supported\n");
+ return (-1);
+ }
+ if ( argc == 1 ){
+
+#ifdef DUMP_MORE_STATE
+ for(i=0; i<NR_CPUS; i++) {
+ int cpus_per_line = 4;
+ if(cpu_online(i)) {
+ if (j++ % cpus_per_line)
+ printk(" %3d",i);
+ else
+ printk("\n %3d",i);
+ }
+ }
+ printk("\n");
+#else
+ printk("\n 0\n");
+#endif
+ } else if((argc==2) && !(strcmp(argv[1],"-l"))) {
+ printk("\nCPUSTATE TASK CPUNUM CPUID HARDCPU(HPA)\n");
+#ifdef DUMP_MORE_STATE
+ for(i=0;i<NR_CPUS;i++) {
+ if (!cpu_online(i))
+ continue;
+ if (cpu_data[i].cpuid != NO_PROC_ID) {
+ switch(cpu_data[i].state) {
+ case STATE_RENDEZVOUS:
+ printk("RENDEZVS ");
+ break;
+ case STATE_RUNNING:
+ printk((current_pid(i)!=0) ? "RUNNING " : "IDLING ");
+ break;
+ case STATE_STOPPED:
+ printk("STOPPED ");
+ break;
+ case STATE_HALTED:
+ printk("HALTED ");
+ break;
+ default:
+ printk("%08x?", cpu_data[i].state);
+ break;
+ }
+ if(cpu_online(i)) {
+ printk(" %4d",current_pid(i));
+ }
+ printk(" %6d",cpu_number_map(i));
+ printk(" %5d",i);
+ printk(" 0x%lx\n",cpu_data[i].hpa);
+ }
+ }
+#else
+ printk("\n%s %4d 0 0 --------",
+ (current->pid)?"RUNNING ": "IDLING ",current->pid);
+#endif
+ } else if ((argc==2) && !(strcmp(argv[1],"-s"))) {
+#ifdef DUMP_MORE_STATE
+ printk("\nCPUSTATE CPUID\n");
+ for (i=0;i<NR_CPUS;i++) {
+ if (!cpu_online(i))
+ continue;
+ if (cpu_data[i].cpuid != NO_PROC_ID) {
+ switch(cpu_data[i].state) {
+ case STATE_RENDEZVOUS:
+ printk("RENDEZVS");break;
+ case STATE_RUNNING:
+ printk((current_pid(i)!=0) ? "RUNNING " : "IDLING");
+ break;
+ case STATE_STOPPED:
+ printk("STOPPED ");break;
+ case STATE_HALTED:
+ printk("HALTED ");break;
+ default:
+ }
+ printk(" %5d\n",i);
+ }
+ }
+#else
+ printk("\n%s CPU0",(current->pid==0)?"RUNNING ":"IDLING ");
+#endif
+ } else {
+ printk("sys_cpus:Unknown request\n");
+ return (-1);
+ }
+ return 0;
+}
+#endif /* ENTRY_SYS_CPUS */
+
+#ifdef CONFIG_PROC_FS
+int __init
+setup_profiling_timer(unsigned int multiplier)
+{
+ return -EINVAL;
+}
+#endif
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-11 10:53:22 +0000