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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/mips/kernel/smp.c
Linux-2.6.12-rc2v2.6.12-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/mips/kernel/smp.c')
-rw-r--r--arch/mips/kernel/smp.c425
1 files changed, 425 insertions, 0 deletions
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
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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.
6 *
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.
11 *
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.
15 *
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
20 */
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
33#include <asm/atomic.h>
34#include <asm/cpu.h>
35#include <asm/processor.h>
36#include <asm/system.h>
37#include <asm/mmu_context.h>
38#include <asm/smp.h>
39
40cpumask_t phys_cpu_present_map; /* Bitmask of available CPUs */
41volatile cpumask_t cpu_callin_map; /* Bitmask of started secondaries */
42cpumask_t cpu_online_map; /* Bitmask of currently online CPUs */
43int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
44int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
45
46EXPORT_SYMBOL(phys_cpu_present_map);
47EXPORT_SYMBOL(cpu_online_map);
48
49static void smp_tune_scheduling (void)
50{
51 struct cache_desc *cd = &current_cpu_data.scache;
52 unsigned long cachesize; /* kB */
53 unsigned long bandwidth = 350; /* MB/s */
54 unsigned long cpu_khz;
55
56 /*
57 * Crude estimate until we actually meassure ...
58 */
59 cpu_khz = loops_per_jiffy * 2 * HZ / 1000;
60
61 /*
62 * Rough estimation for SMP scheduling, this is the number of
63 * cycles it takes for a fully memory-limited process to flush
64 * the SMP-local cache.
65 *
66 * (For a P5 this pretty much means we will choose another idle
67 * CPU almost always at wakeup time (this is due to the small
68 * L1 cache), on PIIs it's around 50-100 usecs, depending on
69 * the cache size)
70 */
71 if (!cpu_khz)
72 return;
73
74 cachesize = cd->linesz * cd->sets * cd->ways;
75}
76
77extern void __init calibrate_delay(void);
78extern ATTRIB_NORET void cpu_idle(void);
79
80/*
81 * First C code run on the secondary CPUs after being started up by
82 * the master.
83 */
84asmlinkage void start_secondary(void)
85{
86 unsigned int cpu = smp_processor_id();
87
88 cpu_probe();
89 cpu_report();
90 per_cpu_trap_init();
91 prom_init_secondary();
92
93 /*
94 * XXX parity protection should be folded in here when it's converted
95 * to an option instead of something based on .cputype
96 */
97
98 calibrate_delay();
99 cpu_data[cpu].udelay_val = loops_per_jiffy;
100
101 prom_smp_finish();
102
103 cpu_set(cpu, cpu_callin_map);
104
105 cpu_idle();
106}
107
108DEFINE_SPINLOCK(smp_call_lock);
109
110struct call_data_struct *call_data;
111
112/*
113 * Run a function on all other CPUs.
114 * <func> The function to run. This must be fast and non-blocking.
115 * <info> An arbitrary pointer to pass to the function.
116 * <retry> If true, keep retrying until ready.
117 * <wait> If true, wait until function has completed on other CPUs.
118 * [RETURNS] 0 on success, else a negative status code.
119 *
120 * Does not return until remote CPUs are nearly ready to execute <func>
121 * or are or have executed.
122 *
123 * You must not call this function with disabled interrupts or from a
124 * hardware interrupt handler or from a bottom half handler.
125 */
126int smp_call_function (void (*func) (void *info), void *info, int retry,
127 int wait)
128{
129 struct call_data_struct data;
130 int i, cpus = num_online_cpus() - 1;
131 int cpu = smp_processor_id();
132
133 if (!cpus)
134 return 0;
135
136 /* Can deadlock when called with interrupts disabled */
137 WARN_ON(irqs_disabled());
138
139 data.func = func;
140 data.info = info;
141 atomic_set(&data.started, 0);
142 data.wait = wait;
143 if (wait)
144 atomic_set(&data.finished, 0);
145
146 spin_lock(&smp_call_lock);
147 call_data = &data;
148 mb();
149
150 /* Send a message to all other CPUs and wait for them to respond */
151 for (i = 0; i < NR_CPUS; i++)
152 if (cpu_online(i) && i != cpu)
153 core_send_ipi(i, SMP_CALL_FUNCTION);
154
155 /* Wait for response */
156 /* FIXME: lock-up detection, backtrace on lock-up */
157 while (atomic_read(&data.started) != cpus)
158 barrier();
159
160 if (wait)
161 while (atomic_read(&data.finished) != cpus)
162 barrier();
163 spin_unlock(&smp_call_lock);
164
165 return 0;
166}
167
168void smp_call_function_interrupt(void)
169{
170 void (*func) (void *info) = call_data->func;
171 void *info = call_data->info;
172 int wait = call_data->wait;
173
174 /*
175 * Notify initiating CPU that I've grabbed the data and am
176 * about to execute the function.
177 */
178 mb();
179 atomic_inc(&call_data->started);
180
181 /*
182 * At this point the info structure may be out of scope unless wait==1.
183 */
184 irq_enter();
185 (*func)(info);
186 irq_exit();
187
188 if (wait) {
189 mb();
190 atomic_inc(&call_data->finished);
191 }
192}
193
194static void stop_this_cpu(void *dummy)
195{
196 /*
197 * Remove this CPU:
198 */
199 cpu_clear(smp_processor_id(), cpu_online_map);
200 local_irq_enable(); /* May need to service _machine_restart IPI */
201 for (;;); /* Wait if available. */
202}
203
204void smp_send_stop(void)
205{
206 smp_call_function(stop_this_cpu, NULL, 1, 0);
207}
208
209void __init smp_cpus_done(unsigned int max_cpus)
210{
211 prom_cpus_done();
212}
213
214/* called from main before smp_init() */
215void __init smp_prepare_cpus(unsigned int max_cpus)
216{
217 cpu_data[0].udelay_val = loops_per_jiffy;
218 init_new_context(current, &init_mm);
219 current_thread_info()->cpu = 0;
220 smp_tune_scheduling();
221 prom_prepare_cpus(max_cpus);
222}
223
224/* preload SMP state for boot cpu */
225void __devinit smp_prepare_boot_cpu(void)
226{
227 /*
228 * This assumes that bootup is always handled by the processor
229 * with the logic and physical number 0.
230 */
231 __cpu_number_map[0] = 0;
232 __cpu_logical_map[0] = 0;
233 cpu_set(0, phys_cpu_present_map);
234 cpu_set(0, cpu_online_map);
235 cpu_set(0, cpu_callin_map);
236}
237
238/*
239 * Startup the CPU with this logical number
240 */
241static int __init do_boot_cpu(int cpu)
242{
243 struct task_struct *idle;
244
245 /*
246 * The following code is purely to make sure
247 * Linux can schedule processes on this slave.
248 */
249 idle = fork_idle(cpu);
250 if (IS_ERR(idle))
251 panic("failed fork for CPU %d\n", cpu);
252
253 prom_boot_secondary(cpu, idle);
254
255 /* XXXKW timeout */
256 while (!cpu_isset(cpu, cpu_callin_map))
257 udelay(100);
258
259 cpu_set(cpu, cpu_online_map);
260
261 return 0;
262}
263
264/*
265 * Called once for each "cpu_possible(cpu)". Needs to spin up the cpu
266 * and keep control until "cpu_online(cpu)" is set. Note: cpu is
267 * physical, not logical.
268 */
269int __devinit __cpu_up(unsigned int cpu)
270{
271 int ret;
272
273 /* Processor goes to start_secondary(), sets online flag */
274 ret = do_boot_cpu(cpu);
275 if (ret < 0)
276 return ret;
277
278 return 0;
279}
280
281/* Not really SMP stuff ... */
282int setup_profiling_timer(unsigned int multiplier)
283{
284 return 0;
285}
286
287static void flush_tlb_all_ipi(void *info)
288{
289 local_flush_tlb_all();
290}
291
292void flush_tlb_all(void)
293{
294 on_each_cpu(flush_tlb_all_ipi, 0, 1, 1);
295}
296
297static void flush_tlb_mm_ipi(void *mm)
298{
299 local_flush_tlb_mm((struct mm_struct *)mm);
300}
301
302/*
303 * The following tlb flush calls are invoked when old translations are
304 * being torn down, or pte attributes are changing. For single threaded
305 * address spaces, a new context is obtained on the current cpu, and tlb
306 * context on other cpus are invalidated to force a new context allocation
307 * at switch_mm time, should the mm ever be used on other cpus. For
308 * multithreaded address spaces, intercpu interrupts have to be sent.
309 * Another case where intercpu interrupts are required is when the target
310 * mm might be active on another cpu (eg debuggers doing the flushes on
311 * behalf of debugees, kswapd stealing pages from another process etc).
312 * Kanoj 07/00.
313 */
314
315void flush_tlb_mm(struct mm_struct *mm)
316{
317 preempt_disable();
318
319 if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
320 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1, 1);
321 } else {
322 int i;
323 for (i = 0; i < num_online_cpus(); i++)
324 if (smp_processor_id() != i)
325 cpu_context(i, mm) = 0;
326 }
327 local_flush_tlb_mm(mm);
328
329 preempt_enable();
330}
331
332struct flush_tlb_data {
333 struct vm_area_struct *vma;
334 unsigned long addr1;
335 unsigned long addr2;
336};
337
338static void flush_tlb_range_ipi(void *info)
339{
340 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
341
342 local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
343}
344
345void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
346{
347 struct mm_struct *mm = vma->vm_mm;
348
349 preempt_disable();
350 if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
351 struct flush_tlb_data fd;
352
353 fd.vma = vma;
354 fd.addr1 = start;
355 fd.addr2 = end;
356 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1, 1);
357 } else {
358 int i;
359 for (i = 0; i < num_online_cpus(); i++)
360 if (smp_processor_id() != i)
361 cpu_context(i, mm) = 0;
362 }
363 local_flush_tlb_range(vma, start, end);
364 preempt_enable();
365}
366
367static void flush_tlb_kernel_range_ipi(void *info)
368{
369 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
370
371 local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
372}
373
374void flush_tlb_kernel_range(unsigned long start, unsigned long end)
375{
376 struct flush_tlb_data fd;
377
378 fd.addr1 = start;
379 fd.addr2 = end;
380 on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1, 1);
381}
382
383static void flush_tlb_page_ipi(void *info)
384{
385 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
386
387 local_flush_tlb_page(fd->vma, fd->addr1);
388}
389
390void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
391{
392 preempt_disable();
393 if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {
394 struct flush_tlb_data fd;
395
396 fd.vma = vma;
397 fd.addr1 = page;
398 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1, 1);
399 } else {
400 int i;
401 for (i = 0; i < num_online_cpus(); i++)
402 if (smp_processor_id() != i)
403 cpu_context(i, vma->vm_mm) = 0;
404 }
405 local_flush_tlb_page(vma, page);
406 preempt_enable();
407}
408
409static void flush_tlb_one_ipi(void *info)
410{
411 unsigned long vaddr = (unsigned long) info;
412
413 local_flush_tlb_one(vaddr);
414}
415
416void flush_tlb_one(unsigned long vaddr)
417{
418 smp_call_function(flush_tlb_one_ipi, (void *) vaddr, 1, 1);
419 local_flush_tlb_one(vaddr);
420}
421
422EXPORT_SYMBOL(flush_tlb_page);
423EXPORT_SYMBOL(flush_tlb_one);
424EXPORT_SYMBOL(cpu_data);
425EXPORT_SYMBOL(synchronize_irq);