Linux 2.6.17.7
[linux/fpc-iii.git] / arch / mips / kernel / smp.c
blob298f82fe8440a43d1a8140ed8a256d44595ed6d8
1 /*
2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public License
4 * as published by the Free Software Foundation; either version 2
5 * of the License, or (at your option) any later version.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
16 * Copyright (C) 2000, 2001 Kanoj Sarcar
17 * Copyright (C) 2000, 2001 Ralf Baechle
18 * Copyright (C) 2000, 2001 Silicon Graphics, Inc.
19 * Copyright (C) 2000, 2001, 2003 Broadcom Corporation
21 #include <linux/cache.h>
22 #include <linux/delay.h>
23 #include <linux/init.h>
24 #include <linux/interrupt.h>
25 #include <linux/spinlock.h>
26 #include <linux/threads.h>
27 #include <linux/module.h>
28 #include <linux/time.h>
29 #include <linux/timex.h>
30 #include <linux/sched.h>
31 #include <linux/cpumask.h>
32 #include <linux/cpu.h>
34 #include <asm/atomic.h>
35 #include <asm/cpu.h>
36 #include <asm/processor.h>
37 #include <asm/system.h>
38 #include <asm/mmu_context.h>
39 #include <asm/smp.h>
41 #ifdef CONFIG_MIPS_MT_SMTC
42 #include <asm/mipsmtregs.h>
43 #endif /* CONFIG_MIPS_MT_SMTC */
45 cpumask_t phys_cpu_present_map; /* Bitmask of available CPUs */
46 volatile cpumask_t cpu_callin_map; /* Bitmask of started secondaries */
47 cpumask_t cpu_online_map; /* Bitmask of currently online CPUs */
48 int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
49 int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
51 EXPORT_SYMBOL(phys_cpu_present_map);
52 EXPORT_SYMBOL(cpu_online_map);
54 static void smp_tune_scheduling (void)
56 struct cache_desc *cd = &current_cpu_data.scache;
57 unsigned long cachesize; /* kB */
58 unsigned long cpu_khz;
61 * Crude estimate until we actually meassure ...
63 cpu_khz = loops_per_jiffy * 2 * HZ / 1000;
66 * Rough estimation for SMP scheduling, this is the number of
67 * cycles it takes for a fully memory-limited process to flush
68 * the SMP-local cache.
70 * (For a P5 this pretty much means we will choose another idle
71 * CPU almost always at wakeup time (this is due to the small
72 * L1 cache), on PIIs it's around 50-100 usecs, depending on
73 * the cache size)
75 if (!cpu_khz)
76 return;
78 cachesize = cd->linesz * cd->sets * cd->ways;
81 extern void __init calibrate_delay(void);
82 extern ATTRIB_NORET void cpu_idle(void);
85 * First C code run on the secondary CPUs after being started up by
86 * the master.
88 asmlinkage void start_secondary(void)
90 unsigned int cpu;
92 #ifdef CONFIG_MIPS_MT_SMTC
93 /* Only do cpu_probe for first TC of CPU */
94 if ((read_c0_tcbind() & TCBIND_CURTC) == 0)
95 #endif /* CONFIG_MIPS_MT_SMTC */
96 cpu_probe();
97 cpu_report();
98 per_cpu_trap_init();
99 prom_init_secondary();
102 * XXX parity protection should be folded in here when it's converted
103 * to an option instead of something based on .cputype
106 calibrate_delay();
107 preempt_disable();
108 cpu = smp_processor_id();
109 cpu_data[cpu].udelay_val = loops_per_jiffy;
111 prom_smp_finish();
113 cpu_set(cpu, cpu_callin_map);
115 cpu_idle();
118 DEFINE_SPINLOCK(smp_call_lock);
120 struct call_data_struct *call_data;
123 * Run a function on all other CPUs.
124 * <func> The function to run. This must be fast and non-blocking.
125 * <info> An arbitrary pointer to pass to the function.
126 * <retry> If true, keep retrying until ready.
127 * <wait> If true, wait until function has completed on other CPUs.
128 * [RETURNS] 0 on success, else a negative status code.
130 * Does not return until remote CPUs are nearly ready to execute <func>
131 * or are or have executed.
133 * You must not call this function with disabled interrupts or from a
134 * hardware interrupt handler or from a bottom half handler:
136 * CPU A CPU B
137 * Disable interrupts
138 * smp_call_function()
139 * Take call_lock
140 * Send IPIs
141 * Wait for all cpus to acknowledge IPI
142 * CPU A has not responded, spin waiting
143 * for cpu A to respond, holding call_lock
144 * smp_call_function()
145 * Spin waiting for call_lock
146 * Deadlock Deadlock
148 int smp_call_function (void (*func) (void *info), void *info, int retry,
149 int wait)
151 struct call_data_struct data;
152 int i, cpus = num_online_cpus() - 1;
153 int cpu = smp_processor_id();
156 * Can die spectacularly if this CPU isn't yet marked online
158 BUG_ON(!cpu_online(cpu));
160 if (!cpus)
161 return 0;
163 /* Can deadlock when called with interrupts disabled */
164 WARN_ON(irqs_disabled());
166 data.func = func;
167 data.info = info;
168 atomic_set(&data.started, 0);
169 data.wait = wait;
170 if (wait)
171 atomic_set(&data.finished, 0);
173 spin_lock(&smp_call_lock);
174 call_data = &data;
175 mb();
177 /* Send a message to all other CPUs and wait for them to respond */
178 for_each_online_cpu(i)
179 if (i != cpu)
180 core_send_ipi(i, SMP_CALL_FUNCTION);
182 /* Wait for response */
183 /* FIXME: lock-up detection, backtrace on lock-up */
184 while (atomic_read(&data.started) != cpus)
185 barrier();
187 if (wait)
188 while (atomic_read(&data.finished) != cpus)
189 barrier();
190 call_data = NULL;
191 spin_unlock(&smp_call_lock);
193 return 0;
197 void smp_call_function_interrupt(void)
199 void (*func) (void *info) = call_data->func;
200 void *info = call_data->info;
201 int wait = call_data->wait;
204 * Notify initiating CPU that I've grabbed the data and am
205 * about to execute the function.
207 mb();
208 atomic_inc(&call_data->started);
211 * At this point the info structure may be out of scope unless wait==1.
213 irq_enter();
214 (*func)(info);
215 irq_exit();
217 if (wait) {
218 mb();
219 atomic_inc(&call_data->finished);
223 static void stop_this_cpu(void *dummy)
226 * Remove this CPU:
228 cpu_clear(smp_processor_id(), cpu_online_map);
229 local_irq_enable(); /* May need to service _machine_restart IPI */
230 for (;;); /* Wait if available. */
233 void smp_send_stop(void)
235 smp_call_function(stop_this_cpu, NULL, 1, 0);
238 void __init smp_cpus_done(unsigned int max_cpus)
240 prom_cpus_done();
243 /* called from main before smp_init() */
244 void __init smp_prepare_cpus(unsigned int max_cpus)
246 init_new_context(current, &init_mm);
247 current_thread_info()->cpu = 0;
248 smp_tune_scheduling();
249 plat_prepare_cpus(max_cpus);
250 #ifndef CONFIG_HOTPLUG_CPU
251 cpu_present_map = cpu_possible_map;
252 #endif
255 /* preload SMP state for boot cpu */
256 void __devinit smp_prepare_boot_cpu(void)
259 * This assumes that bootup is always handled by the processor
260 * with the logic and physical number 0.
262 __cpu_number_map[0] = 0;
263 __cpu_logical_map[0] = 0;
264 cpu_set(0, phys_cpu_present_map);
265 cpu_set(0, cpu_online_map);
266 cpu_set(0, cpu_callin_map);
270 * Called once for each "cpu_possible(cpu)". Needs to spin up the cpu
271 * and keep control until "cpu_online(cpu)" is set. Note: cpu is
272 * physical, not logical.
274 int __devinit __cpu_up(unsigned int cpu)
276 struct task_struct *idle;
279 * Processor goes to start_secondary(), sets online flag
280 * The following code is purely to make sure
281 * Linux can schedule processes on this slave.
283 idle = fork_idle(cpu);
284 if (IS_ERR(idle))
285 panic(KERN_ERR "Fork failed for CPU %d", cpu);
287 prom_boot_secondary(cpu, idle);
290 * Trust is futile. We should really have timeouts ...
292 while (!cpu_isset(cpu, cpu_callin_map))
293 udelay(100);
295 cpu_set(cpu, cpu_online_map);
297 return 0;
300 /* Not really SMP stuff ... */
301 int setup_profiling_timer(unsigned int multiplier)
303 return 0;
306 static void flush_tlb_all_ipi(void *info)
308 local_flush_tlb_all();
311 void flush_tlb_all(void)
313 on_each_cpu(flush_tlb_all_ipi, 0, 1, 1);
316 static void flush_tlb_mm_ipi(void *mm)
318 local_flush_tlb_mm((struct mm_struct *)mm);
322 * The following tlb flush calls are invoked when old translations are
323 * being torn down, or pte attributes are changing. For single threaded
324 * address spaces, a new context is obtained on the current cpu, and tlb
325 * context on other cpus are invalidated to force a new context allocation
326 * at switch_mm time, should the mm ever be used on other cpus. For
327 * multithreaded address spaces, intercpu interrupts have to be sent.
328 * Another case where intercpu interrupts are required is when the target
329 * mm might be active on another cpu (eg debuggers doing the flushes on
330 * behalf of debugees, kswapd stealing pages from another process etc).
331 * Kanoj 07/00.
334 void flush_tlb_mm(struct mm_struct *mm)
336 preempt_disable();
338 if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
339 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1, 1);
340 } else {
341 int i;
342 for (i = 0; i < num_online_cpus(); i++)
343 if (smp_processor_id() != i)
344 cpu_context(i, mm) = 0;
346 local_flush_tlb_mm(mm);
348 preempt_enable();
351 struct flush_tlb_data {
352 struct vm_area_struct *vma;
353 unsigned long addr1;
354 unsigned long addr2;
357 static void flush_tlb_range_ipi(void *info)
359 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
361 local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
364 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
366 struct mm_struct *mm = vma->vm_mm;
368 preempt_disable();
369 if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
370 struct flush_tlb_data fd;
372 fd.vma = vma;
373 fd.addr1 = start;
374 fd.addr2 = end;
375 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1, 1);
376 } else {
377 int i;
378 for (i = 0; i < num_online_cpus(); i++)
379 if (smp_processor_id() != i)
380 cpu_context(i, mm) = 0;
382 local_flush_tlb_range(vma, start, end);
383 preempt_enable();
386 static void flush_tlb_kernel_range_ipi(void *info)
388 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
390 local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
393 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
395 struct flush_tlb_data fd;
397 fd.addr1 = start;
398 fd.addr2 = end;
399 on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1, 1);
402 static void flush_tlb_page_ipi(void *info)
404 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
406 local_flush_tlb_page(fd->vma, fd->addr1);
409 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
411 preempt_disable();
412 if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {
413 struct flush_tlb_data fd;
415 fd.vma = vma;
416 fd.addr1 = page;
417 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1, 1);
418 } else {
419 int i;
420 for (i = 0; i < num_online_cpus(); i++)
421 if (smp_processor_id() != i)
422 cpu_context(i, vma->vm_mm) = 0;
424 local_flush_tlb_page(vma, page);
425 preempt_enable();
428 static void flush_tlb_one_ipi(void *info)
430 unsigned long vaddr = (unsigned long) info;
432 local_flush_tlb_one(vaddr);
435 void flush_tlb_one(unsigned long vaddr)
437 smp_call_function(flush_tlb_one_ipi, (void *) vaddr, 1, 1);
438 local_flush_tlb_one(vaddr);
441 static DEFINE_PER_CPU(struct cpu, cpu_devices);
443 static int __init topology_init(void)
445 int cpu;
446 int ret;
448 for_each_present_cpu(cpu) {
449 ret = register_cpu(&per_cpu(cpu_devices, cpu), cpu, NULL);
450 if (ret)
451 printk(KERN_WARNING "topology_init: register_cpu %d "
452 "failed (%d)\n", cpu, ret);
455 return 0;
458 subsys_initcall(topology_init);
460 EXPORT_SYMBOL(flush_tlb_page);
461 EXPORT_SYMBOL(flush_tlb_one);