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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/ia64/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/ia64/kernel/smp.c')
-rw-r--r--arch/ia64/kernel/smp.c376
1 files changed, 376 insertions, 0 deletions
diff --git a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c
new file mode 100644
index 000000000000..953095e2ce15
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+++ b/arch/ia64/kernel/smp.c
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1/*
2 * SMP Support
3 *
4 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
5 * Copyright (C) 1999, 2001, 2003 David Mosberger-Tang <davidm@hpl.hp.com>
6 *
7 * Lots of stuff stolen from arch/alpha/kernel/smp.c
8 *
9 * 01/05/16 Rohit Seth <rohit.seth@intel.com> IA64-SMP functions. Reorganized
10 * the existing code (on the lines of x86 port).
11 * 00/09/11 David Mosberger <davidm@hpl.hp.com> Do loops_per_jiffy
12 * calibration on each CPU.
13 * 00/08/23 Asit Mallick <asit.k.mallick@intel.com> fixed logical processor id
14 * 00/03/31 Rohit Seth <rohit.seth@intel.com> Fixes for Bootstrap Processor
15 * & cpu_online_map now gets done here (instead of setup.c)
16 * 99/10/05 davidm Update to bring it in sync with new command-line processing
17 * scheme.
18 * 10/13/00 Goutham Rao <goutham.rao@intel.com> Updated smp_call_function and
19 * smp_call_function_single to resend IPI on timeouts
20 */
21#include <linux/module.h>
22#include <linux/kernel.h>
23#include <linux/sched.h>
24#include <linux/init.h>
25#include <linux/interrupt.h>
26#include <linux/smp.h>
27#include <linux/kernel_stat.h>
28#include <linux/mm.h>
29#include <linux/cache.h>
30#include <linux/delay.h>
31#include <linux/efi.h>
32#include <linux/bitops.h>
33
34#include <asm/atomic.h>
35#include <asm/current.h>
36#include <asm/delay.h>
37#include <asm/machvec.h>
38#include <asm/io.h>
39#include <asm/irq.h>
40#include <asm/page.h>
41#include <asm/pgalloc.h>
42#include <asm/pgtable.h>
43#include <asm/processor.h>
44#include <asm/ptrace.h>
45#include <asm/sal.h>
46#include <asm/system.h>
47#include <asm/tlbflush.h>
48#include <asm/unistd.h>
49#include <asm/mca.h>
50
51/*
52 * Structure and data for smp_call_function(). This is designed to minimise static memory
53 * requirements. It also looks cleaner.
54 */
55static __cacheline_aligned DEFINE_SPINLOCK(call_lock);
56
57struct call_data_struct {
58 void (*func) (void *info);
59 void *info;
60 long wait;
61 atomic_t started;
62 atomic_t finished;
63};
64
65static volatile struct call_data_struct *call_data;
66
67#define IPI_CALL_FUNC 0
68#define IPI_CPU_STOP 1
69
70/* This needs to be cacheline aligned because it is written to by *other* CPUs. */
71static DEFINE_PER_CPU(u64, ipi_operation) ____cacheline_aligned;
72
73extern void cpu_halt (void);
74
75void
76lock_ipi_calllock(void)
77{
78 spin_lock_irq(&call_lock);
79}
80
81void
82unlock_ipi_calllock(void)
83{
84 spin_unlock_irq(&call_lock);
85}
86
87static void
88stop_this_cpu (void)
89{
90 /*
91 * Remove this CPU:
92 */
93 cpu_clear(smp_processor_id(), cpu_online_map);
94 max_xtp();
95 local_irq_disable();
96 cpu_halt();
97}
98
99void
100cpu_die(void)
101{
102 max_xtp();
103 local_irq_disable();
104 cpu_halt();
105 /* Should never be here */
106 BUG();
107 for (;;);
108}
109
110irqreturn_t
111handle_IPI (int irq, void *dev_id, struct pt_regs *regs)
112{
113 int this_cpu = get_cpu();
114 unsigned long *pending_ipis = &__ia64_per_cpu_var(ipi_operation);
115 unsigned long ops;
116
117 mb(); /* Order interrupt and bit testing. */
118 while ((ops = xchg(pending_ipis, 0)) != 0) {
119 mb(); /* Order bit clearing and data access. */
120 do {
121 unsigned long which;
122
123 which = ffz(~ops);
124 ops &= ~(1 << which);
125
126 switch (which) {
127 case IPI_CALL_FUNC:
128 {
129 struct call_data_struct *data;
130 void (*func)(void *info);
131 void *info;
132 int wait;
133
134 /* release the 'pointer lock' */
135 data = (struct call_data_struct *) call_data;
136 func = data->func;
137 info = data->info;
138 wait = data->wait;
139
140 mb();
141 atomic_inc(&data->started);
142 /*
143 * At this point the structure may be gone unless
144 * wait is true.
145 */
146 (*func)(info);
147
148 /* Notify the sending CPU that the task is done. */
149 mb();
150 if (wait)
151 atomic_inc(&data->finished);
152 }
153 break;
154
155 case IPI_CPU_STOP:
156 stop_this_cpu();
157 break;
158
159 default:
160 printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n", this_cpu, which);
161 break;
162 }
163 } while (ops);
164 mb(); /* Order data access and bit testing. */
165 }
166 put_cpu();
167 return IRQ_HANDLED;
168}
169
170/*
171 * Called with preeemption disabled.
172 */
173static inline void
174send_IPI_single (int dest_cpu, int op)
175{
176 set_bit(op, &per_cpu(ipi_operation, dest_cpu));
177 platform_send_ipi(dest_cpu, IA64_IPI_VECTOR, IA64_IPI_DM_INT, 0);
178}
179
180/*
181 * Called with preeemption disabled.
182 */
183static inline void
184send_IPI_allbutself (int op)
185{
186 unsigned int i;
187
188 for (i = 0; i < NR_CPUS; i++) {
189 if (cpu_online(i) && i != smp_processor_id())
190 send_IPI_single(i, op);
191 }
192}
193
194/*
195 * Called with preeemption disabled.
196 */
197static inline void
198send_IPI_all (int op)
199{
200 int i;
201
202 for (i = 0; i < NR_CPUS; i++)
203 if (cpu_online(i))
204 send_IPI_single(i, op);
205}
206
207/*
208 * Called with preeemption disabled.
209 */
210static inline void
211send_IPI_self (int op)
212{
213 send_IPI_single(smp_processor_id(), op);
214}
215
216/*
217 * Called with preeemption disabled.
218 */
219void
220smp_send_reschedule (int cpu)
221{
222 platform_send_ipi(cpu, IA64_IPI_RESCHEDULE, IA64_IPI_DM_INT, 0);
223}
224
225void
226smp_flush_tlb_all (void)
227{
228 on_each_cpu((void (*)(void *))local_flush_tlb_all, NULL, 1, 1);
229}
230
231void
232smp_flush_tlb_mm (struct mm_struct *mm)
233{
234 /* this happens for the common case of a single-threaded fork(): */
235 if (likely(mm == current->active_mm && atomic_read(&mm->mm_users) == 1))
236 {
237 local_finish_flush_tlb_mm(mm);
238 return;
239 }
240
241 /*
242 * We could optimize this further by using mm->cpu_vm_mask to track which CPUs
243 * have been running in the address space. It's not clear that this is worth the
244 * trouble though: to avoid races, we have to raise the IPI on the target CPU
245 * anyhow, and once a CPU is interrupted, the cost of local_flush_tlb_all() is
246 * rather trivial.
247 */
248 on_each_cpu((void (*)(void *))local_finish_flush_tlb_mm, mm, 1, 1);
249}
250
251/*
252 * Run a function on another CPU
253 * <func> The function to run. This must be fast and non-blocking.
254 * <info> An arbitrary pointer to pass to the function.
255 * <nonatomic> Currently unused.
256 * <wait> If true, wait until function has completed on other CPUs.
257 * [RETURNS] 0 on success, else a negative status code.
258 *
259 * Does not return until the remote CPU is nearly ready to execute <func>
260 * or is or has executed.
261 */
262
263int
264smp_call_function_single (int cpuid, void (*func) (void *info), void *info, int nonatomic,
265 int wait)
266{
267 struct call_data_struct data;
268 int cpus = 1;
269 int me = get_cpu(); /* prevent preemption and reschedule on another processor */
270
271 if (cpuid == me) {
272 printk("%s: trying to call self\n", __FUNCTION__);
273 put_cpu();
274 return -EBUSY;
275 }
276
277 data.func = func;
278 data.info = info;
279 atomic_set(&data.started, 0);
280 data.wait = wait;
281 if (wait)
282 atomic_set(&data.finished, 0);
283
284 spin_lock_bh(&call_lock);
285
286 call_data = &data;
287 mb(); /* ensure store to call_data precedes setting of IPI_CALL_FUNC */
288 send_IPI_single(cpuid, IPI_CALL_FUNC);
289
290 /* Wait for response */
291 while (atomic_read(&data.started) != cpus)
292 cpu_relax();
293
294 if (wait)
295 while (atomic_read(&data.finished) != cpus)
296 cpu_relax();
297 call_data = NULL;
298
299 spin_unlock_bh(&call_lock);
300 put_cpu();
301 return 0;
302}
303EXPORT_SYMBOL(smp_call_function_single);
304
305/*
306 * this function sends a 'generic call function' IPI to all other CPUs
307 * in the system.
308 */
309
310/*
311 * [SUMMARY] Run a function on all other CPUs.
312 * <func> The function to run. This must be fast and non-blocking.
313 * <info> An arbitrary pointer to pass to the function.
314 * <nonatomic> currently unused.
315 * <wait> If true, wait (atomically) until function has completed on other CPUs.
316 * [RETURNS] 0 on success, else a negative status code.
317 *
318 * Does not return until remote CPUs are nearly ready to execute <func> or are or have
319 * executed.
320 *
321 * You must not call this function with disabled interrupts or from a
322 * hardware interrupt handler or from a bottom half handler.
323 */
324int
325smp_call_function (void (*func) (void *info), void *info, int nonatomic, int wait)
326{
327 struct call_data_struct data;
328 int cpus = num_online_cpus()-1;
329
330 if (!cpus)
331 return 0;
332
333 /* Can deadlock when called with interrupts disabled */
334 WARN_ON(irqs_disabled());
335
336 data.func = func;
337 data.info = info;
338 atomic_set(&data.started, 0);
339 data.wait = wait;
340 if (wait)
341 atomic_set(&data.finished, 0);
342
343 spin_lock(&call_lock);
344
345 call_data = &data;
346 mb(); /* ensure store to call_data precedes setting of IPI_CALL_FUNC */
347 send_IPI_allbutself(IPI_CALL_FUNC);
348
349 /* Wait for response */
350 while (atomic_read(&data.started) != cpus)
351 cpu_relax();
352
353 if (wait)
354 while (atomic_read(&data.finished) != cpus)
355 cpu_relax();
356 call_data = NULL;
357
358 spin_unlock(&call_lock);
359 return 0;
360}
361EXPORT_SYMBOL(smp_call_function);
362
363/*
364 * this function calls the 'stop' function on all other CPUs in the system.
365 */
366void
367smp_send_stop (void)
368{
369 send_IPI_allbutself(IPI_CPU_STOP);
370}
371
372int __init
373setup_profiling_timer (unsigned int multiplier)
374{
375 return -EINVAL;
376}