diff options
Diffstat (limited to 'arch/mips/kernel/smp.c')
| -rw-r--r-- | arch/mips/kernel/smp.c | 51 |
1 files changed, 27 insertions, 24 deletions
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index af5cd3b8a39..fcacf1aae98 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -50,7 +50,6 @@ static void smp_tune_scheduling (void) { struct cache_desc *cd = ¤t_cpu_data.scache; unsigned long cachesize; /* kB */ - unsigned long bandwidth = 350; /* MB/s */ unsigned long cpu_khz; /* @@ -121,7 +120,19 @@ struct call_data_struct *call_data; * or are or have executed. * * You must not call this function with disabled interrupts or from a - * hardware interrupt handler or from a bottom half handler. + * hardware interrupt handler or from a bottom half handler: + * + * CPU A CPU B + * Disable interrupts + * smp_call_function() + * Take call_lock + * Send IPIs + * Wait for all cpus to acknowledge IPI + * CPU A has not responded, spin waiting + * for cpu A to respond, holding call_lock + * smp_call_function() + * Spin waiting for call_lock + * Deadlock Deadlock */ int smp_call_function (void (*func) (void *info), void *info, int retry, int wait) @@ -130,6 +141,11 @@ int smp_call_function (void (*func) (void *info), void *info, int retry, int i, cpus = num_online_cpus() - 1; int cpu = smp_processor_id(); + /* + * Can die spectacularly if this CPU isn't yet marked online + */ + BUG_ON(!cpu_online(cpu)); + if (!cpus) return 0; @@ -214,7 +230,6 @@ void __init smp_cpus_done(unsigned int max_cpus) /* called from main before smp_init() */ void __init smp_prepare_cpus(unsigned int max_cpus) { - cpu_data[0].udelay_val = loops_per_jiffy; init_new_context(current, &init_mm); current_thread_info()->cpu = 0; smp_tune_scheduling(); @@ -236,23 +251,28 @@ void __devinit smp_prepare_boot_cpu(void) } /* - * Startup the CPU with this logical number + * Called once for each "cpu_possible(cpu)". Needs to spin up the cpu + * and keep control until "cpu_online(cpu)" is set. Note: cpu is + * physical, not logical. */ -static int __init do_boot_cpu(int cpu) +int __devinit __cpu_up(unsigned int cpu) { struct task_struct *idle; /* + * Processor goes to start_secondary(), sets online flag * The following code is purely to make sure * Linux can schedule processes on this slave. */ idle = fork_idle(cpu); if (IS_ERR(idle)) - panic("failed fork for CPU %d\n", cpu); + panic(KERN_ERR "Fork failed for CPU %d", cpu); prom_boot_secondary(cpu, idle); - /* XXXKW timeout */ + /* + * Trust is futile. We should really have timeouts ... + */ while (!cpu_isset(cpu, cpu_callin_map)) udelay(100); @@ -261,23 +281,6 @@ static int __init do_boot_cpu(int cpu) return 0; } -/* - * Called once for each "cpu_possible(cpu)". Needs to spin up the cpu - * and keep control until "cpu_online(cpu)" is set. Note: cpu is - * physical, not logical. - */ -int __devinit __cpu_up(unsigned int cpu) -{ - int ret; - - /* Processor goes to start_secondary(), sets online flag */ - ret = do_boot_cpu(cpu); - if (ret < 0) - return ret; - - return 0; -} - /* Not really SMP stuff ... */ int setup_profiling_timer(unsigned int multiplier) { |