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 "user_util.h" 25 #include "kern_util.h" 26 #include "kern.h" 27 #include "irq_user.h" 28 #include "os.h" 29 30 /* CPU online map, set by smp_boot_cpus */ 31 cpumask_t cpu_online_map = CPU_MASK_NONE; 32 cpumask_t cpu_possible_map = CPU_MASK_NONE; 33 34 EXPORT_SYMBOL(cpu_online_map); 35 EXPORT_SYMBOL(cpu_possible_map); 36 37 /* Per CPU bogomips and other parameters 38 * The only piece used here is the ipi pipe, which is set before SMP is 39 * started and never changed. 40 */ 41 struct cpuinfo_um cpu_data[NR_CPUS]; 42 43 /* A statistic, can be a little off */ 44 int num_reschedules_sent = 0; 45 46 /* Not changed after boot */ 47 struct task_struct *idle_threads[NR_CPUS]; 48 49 void smp_send_reschedule(int cpu) 50 { 51 os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1); 52 num_reschedules_sent++; 53 } 54 55 void smp_send_stop(void) 56 { 57 int i; 58 59 printk(KERN_INFO "Stopping all CPUs..."); 60 for(i = 0; i < num_online_cpus(); i++){ 61 if(i == current_thread->cpu) 62 continue; 63 os_write_file(cpu_data[i].ipi_pipe[1], "S", 1); 64 } 65 printk("done\n"); 66 } 67 68 static cpumask_t smp_commenced_mask = CPU_MASK_NONE; 69 static cpumask_t cpu_callin_map = CPU_MASK_NONE; 70 71 static int idle_proc(void *cpup) 72 { 73 int cpu = (int) cpup, err; 74 75 err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1); 76 if(err < 0) 77 panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err); 78 79 os_set_fd_async(cpu_data[cpu].ipi_pipe[0], 80 current->thread.mode.tt.extern_pid); 81 82 wmb(); 83 if (cpu_test_and_set(cpu, cpu_callin_map)) { 84 printk("huh, CPU#%d already present??\n", cpu); 85 BUG(); 86 } 87 88 while (!cpu_isset(cpu, smp_commenced_mask)) 89 cpu_relax(); 90 91 cpu_set(cpu, cpu_online_map); 92 default_idle(); 93 return(0); 94 } 95 96 static struct task_struct *idle_thread(int cpu) 97 { 98 struct task_struct *new_task; 99 unsigned char c; 100 101 current->thread.request.u.thread.proc = idle_proc; 102 current->thread.request.u.thread.arg = (void *) cpu; 103 new_task = fork_idle(cpu); 104 if(IS_ERR(new_task)) 105 panic("copy_process failed in idle_thread, error = %ld", 106 PTR_ERR(new_task)); 107 108 cpu_tasks[cpu] = ((struct cpu_task) 109 { .pid = new_task->thread.mode.tt.extern_pid, 110 .task = new_task } ); 111 idle_threads[cpu] = new_task; 112 CHOOSE_MODE(os_write_file(new_task->thread.mode.tt.switch_pipe[1], &c, 113 sizeof(c)), 114 ({ panic("skas mode doesn't support SMP"); })); 115 return(new_task); 116 } 117 118 void smp_prepare_cpus(unsigned int maxcpus) 119 { 120 struct task_struct *idle; 121 unsigned long waittime; 122 int err, cpu, me = smp_processor_id(); 123 int i; 124 125 for (i = 0; i < ncpus; ++i) 126 cpu_set(i, cpu_possible_map); 127 128 cpu_clear(me, cpu_online_map); 129 cpu_set(me, cpu_online_map); 130 cpu_set(me, cpu_callin_map); 131 132 err = os_pipe(cpu_data[me].ipi_pipe, 1, 1); 133 if(err < 0) 134 panic("CPU#0 failed to create IPI pipe, errno = %d", -err); 135 136 os_set_fd_async(cpu_data[me].ipi_pipe[0], 137 current->thread.mode.tt.extern_pid); 138 139 for(cpu = 1; cpu < ncpus; cpu++){ 140 printk("Booting processor %d...\n", cpu); 141 142 idle = idle_thread(cpu); 143 144 init_idle(idle, cpu); 145 146 waittime = 200000000; 147 while (waittime-- && !cpu_isset(cpu, cpu_callin_map)) 148 cpu_relax(); 149 150 if (cpu_isset(cpu, cpu_callin_map)) 151 printk("done\n"); 152 else printk("failed\n"); 153 } 154 } 155 156 void smp_prepare_boot_cpu(void) 157 { 158 cpu_set(smp_processor_id(), cpu_online_map); 159 } 160 161 int __cpu_up(unsigned int cpu) 162 { 163 cpu_set(cpu, smp_commenced_mask); 164 while (!cpu_isset(cpu, cpu_online_map)) 165 mb(); 166 return(0); 167 } 168 169 int setup_profiling_timer(unsigned int multiplier) 170 { 171 printk(KERN_INFO "setup_profiling_timer\n"); 172 return(0); 173 } 174 175 void smp_call_function_slave(int cpu); 176 177 void IPI_handler(int cpu) 178 { 179 unsigned char c; 180 int fd; 181 182 fd = cpu_data[cpu].ipi_pipe[0]; 183 while (os_read_file(fd, &c, 1) == 1) { 184 switch (c) { 185 case 'C': 186 smp_call_function_slave(cpu); 187 break; 188 189 case 'R': 190 set_tsk_need_resched(current); 191 break; 192 193 case 'S': 194 printk("CPU#%d stopping\n", cpu); 195 while(1) 196 pause(); 197 break; 198 199 default: 200 printk("CPU#%d received unknown IPI [%c]!\n", cpu, c); 201 break; 202 } 203 } 204 } 205 206 int hard_smp_processor_id(void) 207 { 208 return(pid_to_processor_id(os_getpid())); 209 } 210 211 static DEFINE_SPINLOCK(call_lock); 212 static atomic_t scf_started; 213 static atomic_t scf_finished; 214 static void (*func)(void *info); 215 static void *info; 216 217 void smp_call_function_slave(int cpu) 218 { 219 atomic_inc(&scf_started); 220 (*func)(info); 221 atomic_inc(&scf_finished); 222 } 223 224 int smp_call_function(void (*_func)(void *info), void *_info, int nonatomic, 225 int wait) 226 { 227 int cpus = num_online_cpus() - 1; 228 int i; 229 230 if (!cpus) 231 return 0; 232 233 /* Can deadlock when called with interrupts disabled */ 234 WARN_ON(irqs_disabled()); 235 236 spin_lock_bh(&call_lock); 237 atomic_set(&scf_started, 0); 238 atomic_set(&scf_finished, 0); 239 func = _func; 240 info = _info; 241 242 for_each_online_cpu(i) 243 os_write_file(cpu_data[i].ipi_pipe[1], "C", 1); 244 245 while (atomic_read(&scf_started) != cpus) 246 barrier(); 247 248 if (wait) 249 while (atomic_read(&scf_finished) != cpus) 250 barrier(); 251 252 spin_unlock_bh(&call_lock); 253 return 0; 254 } 255 256 #endif 257 258 /* 259 * Overrides for Emacs so that we follow Linus's tabbing style. 260 * Emacs will notice this stuff at the end of the file and automatically 261 * adjust the settings for this buffer only. This must remain at the end 262 * of the file. 263 * --------------------------------------------------------------------------- 264 * Local variables: 265 * c-file-style: "linux" 266 * End: 267 */ 268