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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/parisc/kernel/smp.c | |
download | linux-fsl-qoriq-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/parisc/kernel/smp.c')
-rw-r--r-- | arch/parisc/kernel/smp.c | 723 |
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 0000000..bcc7e83 --- /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 |