1 /* 2 * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com) 3 * Licensed under the GPL 4 */ 5 6 #include "linux/percpu.h" 7 #include "asm/pgalloc.h" 8 #include "asm/tlb.h" 9 10 /* For some reason, mmu_gathers are referenced when CONFIG_SMP is off. */ 11 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 12 13 #ifdef CONFIG_SMP 14 15 #include "linux/sched.h" 16 #include "linux/module.h" 17 #include "linux/threads.h" 18 #include "linux/interrupt.h" 19 #include "linux/err.h" 20 #include "linux/hardirq.h" 21 #include "asm/smp.h" 22 #include "asm/processor.h" 23 #include "asm/spinlock.h" 24 #include "kern_util.h" 25 #include "kern.h" 26 #include "irq_user.h" 27 #include "os.h" 28 29 /* CPU online map, set by smp_boot_cpus */ 30 cpumask_t cpu_online_map = CPU_MASK_NONE; 31 cpumask_t cpu_possible_map = CPU_MASK_NONE; 32 33 EXPORT_SYMBOL(cpu_online_map); 34 EXPORT_SYMBOL(cpu_possible_map); 35 36 /* Per CPU bogomips and other parameters 37 * The only piece used here is the ipi pipe, which is set before SMP is 38 * started and never changed. 39 */ 40 struct cpuinfo_um cpu_data[NR_CPUS]; 41 42 /* A statistic, can be a little off */ 43 int num_reschedules_sent = 0; 44 45 /* Not changed after boot */ 46 struct task_struct *idle_threads[NR_CPUS]; 47 48 void smp_send_reschedule(int cpu) 49 { 50 os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1); 51 num_reschedules_sent++; 52 } 53 54 void smp_send_stop(void) 55 { 56 int i; 57 58 printk(KERN_INFO "Stopping all CPUs..."); 59 for(i = 0; i < num_online_cpus(); i++){ 60 if(i == current_thread->cpu) 61 continue; 62 os_write_file(cpu_data[i].ipi_pipe[1], "S", 1); 63 } 64 printk("done\n"); 65 } 66 67 static cpumask_t smp_commenced_mask = CPU_MASK_NONE; 68 static cpumask_t cpu_callin_map = CPU_MASK_NONE; 69 70 static int idle_proc(void *cpup) 71 { 72 int cpu = (int) cpup, err; 73 74 err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1); 75 if(err < 0) 76 panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err); 77 78 os_set_fd_async(cpu_data[cpu].ipi_pipe[0], 79 current->thread.mode.tt.extern_pid); 80 81 wmb(); 82 if (cpu_test_and_set(cpu, cpu_callin_map)) { 83 printk("huh, CPU#%d already present??\n", cpu); 84 BUG(); 85 } 86 87 while (!cpu_isset(cpu, smp_commenced_mask)) 88 cpu_relax(); 89 90 cpu_set(cpu, cpu_online_map); 91 default_idle(); 92 return 0; 93 } 94 95 static struct task_struct *idle_thread(int cpu) 96 { 97 struct task_struct *new_task; 98 unsigned char c; 99 100 current->thread.request.u.thread.proc = idle_proc; 101 current->thread.request.u.thread.arg = (void *) cpu; 102 new_task = fork_idle(cpu); 103 if(IS_ERR(new_task)) 104 panic("copy_process failed in idle_thread, error = %ld", 105 PTR_ERR(new_task)); 106 107 cpu_tasks[cpu] = ((struct cpu_task) 108 { .pid = new_task->thread.mode.tt.extern_pid, 109 .task = new_task } ); 110 idle_threads[cpu] = new_task; 111 CHOOSE_MODE(os_write_file(new_task->thread.mode.tt.switch_pipe[1], &c, 112 sizeof(c)), 113 ({ panic("skas mode doesn't support SMP"); })); 114 return new_task; 115 } 116 117 void smp_prepare_cpus(unsigned int maxcpus) 118 { 119 struct task_struct *idle; 120 unsigned long waittime; 121 int err, cpu, me = smp_processor_id(); 122 int i; 123 124 for (i = 0; i < ncpus; ++i) 125 cpu_set(i, cpu_possible_map); 126 127 cpu_clear(me, cpu_online_map); 128 cpu_set(me, cpu_online_map); 129 cpu_set(me, cpu_callin_map); 130 131 err = os_pipe(cpu_data[me].ipi_pipe, 1, 1); 132 if(err < 0) 133 panic("CPU#0 failed to create IPI pipe, errno = %d", -err); 134 135 os_set_fd_async(cpu_data[me].ipi_pipe[0], 136 current->thread.mode.tt.extern_pid); 137 138 for(cpu = 1; cpu < ncpus; cpu++){ 139 printk("Booting processor %d...\n", cpu); 140 141 idle = idle_thread(cpu); 142 143 init_idle(idle, cpu); 144 145 waittime = 200000000; 146 while (waittime-- && !cpu_isset(cpu, cpu_callin_map)) 147 cpu_relax(); 148 149 if (cpu_isset(cpu, cpu_callin_map)) 150 printk("done\n"); 151 else printk("failed\n"); 152 } 153 } 154 155 void smp_prepare_boot_cpu(void) 156 { 157 cpu_set(smp_processor_id(), cpu_online_map); 158 } 159 160 int __cpu_up(unsigned int cpu) 161 { 162 cpu_set(cpu, smp_commenced_mask); 163 while (!cpu_isset(cpu, cpu_online_map)) 164 mb(); 165 return 0; 166 } 167 168 int setup_profiling_timer(unsigned int multiplier) 169 { 170 printk(KERN_INFO "setup_profiling_timer\n"); 171 return 0; 172 } 173 174 void smp_call_function_slave(int cpu); 175 176 void IPI_handler(int cpu) 177 { 178 unsigned char c; 179 int fd; 180 181 fd = cpu_data[cpu].ipi_pipe[0]; 182 while (os_read_file(fd, &c, 1) == 1) { 183 switch (c) { 184 case 'C': 185 smp_call_function_slave(cpu); 186 break; 187 188 case 'R': 189 set_tsk_need_resched(current); 190 break; 191 192 case 'S': 193 printk("CPU#%d stopping\n", cpu); 194 while(1) 195 pause(); 196 break; 197 198 default: 199 printk("CPU#%d received unknown IPI [%c]!\n", cpu, c); 200 break; 201 } 202 } 203 } 204 205 int hard_smp_processor_id(void) 206 { 207 return pid_to_processor_id(os_getpid()); 208 } 209 210 static DEFINE_SPINLOCK(call_lock); 211 static atomic_t scf_started; 212 static atomic_t scf_finished; 213 static void (*func)(void *info); 214 static void *info; 215 216 void smp_call_function_slave(int cpu) 217 { 218 atomic_inc(&scf_started); 219 (*func)(info); 220 atomic_inc(&scf_finished); 221 } 222 223 int smp_call_function(void (*_func)(void *info), void *_info, int nonatomic, 224 int wait) 225 { 226 int cpus = num_online_cpus() - 1; 227 int i; 228 229 if (!cpus) 230 return 0; 231 232 /* Can deadlock when called with interrupts disabled */ 233 WARN_ON(irqs_disabled()); 234 235 spin_lock_bh(&call_lock); 236 atomic_set(&scf_started, 0); 237 atomic_set(&scf_finished, 0); 238 func = _func; 239 info = _info; 240 241 for_each_online_cpu(i) 242 os_write_file(cpu_data[i].ipi_pipe[1], "C", 1); 243 244 while (atomic_read(&scf_started) != cpus) 245 barrier(); 246 247 if (wait) 248 while (atomic_read(&scf_finished) != cpus) 249 barrier(); 250 251 spin_unlock_bh(&call_lock); 252 return 0; 253 } 254 255 #endif 256