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authorYi Li <yi.li@analog.com>2009-01-07 10:14:39 -0500
committerBryan Wu <cooloney@kernel.org>2009-01-07 10:14:39 -0500
commit6a01f230339321292cf065551f8cf55361052461 (patch)
tree7ac2ac8fc9f05a7315ef6a7f6f0a387433c62c14 /arch/blackfin/kernel/ipipe.c
parent5105432a3201e3f0e6c219cd0a74feee1e5e262b (diff)
Blackfin arch: merge adeos blackfin part to arch/blackfin/
[Mike Frysinger <vapier.adi@gmail.com>: - handle bf531/bf532/bf534/bf536 variants in ipipe.h - cleanup IPIPE logic for bfin_set_irq_handler() - cleanup ipipe asm code a bit and add missing ENDPROC() - simplify IPIPE code in trap_c - unify some of the IPIPE code and fix style - simplify DO_IRQ_L1 handling with ipipe code - revert IRQ_SW_INT# addition from ipipe merge - remove duplicate get_{c,s}clk() prototypes ] Signed-off-by: Yi Li <yi.li@analog.com> Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Signed-off-by: Bryan Wu <cooloney@kernel.org>
Diffstat (limited to 'arch/blackfin/kernel/ipipe.c')
-rw-r--r--arch/blackfin/kernel/ipipe.c428
1 files changed, 428 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/ipipe.c b/arch/blackfin/kernel/ipipe.c
new file mode 100644
index 000000000000..339be5a3ae6a
--- /dev/null
+++ b/arch/blackfin/kernel/ipipe.c
@@ -0,0 +1,428 @@
1/* -*- linux-c -*-
2 * linux/arch/blackfin/kernel/ipipe.c
3 *
4 * Copyright (C) 2005-2007 Philippe Gerum.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
9 * USA; either version 2 of the License, or (at your option) any later
10 * version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 *
21 * Architecture-dependent I-pipe support for the Blackfin.
22 */
23
24#include <linux/kernel.h>
25#include <linux/sched.h>
26#include <linux/module.h>
27#include <linux/interrupt.h>
28#include <linux/percpu.h>
29#include <linux/bitops.h>
30#include <linux/slab.h>
31#include <linux/errno.h>
32#include <linux/kthread.h>
33#include <asm/unistd.h>
34#include <asm/system.h>
35#include <asm/atomic.h>
36#include <asm/io.h>
37
38static int create_irq_threads;
39
40DEFINE_PER_CPU(struct pt_regs, __ipipe_tick_regs);
41
42static DEFINE_PER_CPU(unsigned long, pending_irqthread_mask);
43
44static DEFINE_PER_CPU(int [IVG13 + 1], pending_irq_count);
45
46asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs);
47
48static void __ipipe_no_irqtail(void);
49
50unsigned long __ipipe_irq_tail_hook = (unsigned long)&__ipipe_no_irqtail;
51EXPORT_SYMBOL(__ipipe_irq_tail_hook);
52
53unsigned long __ipipe_core_clock;
54EXPORT_SYMBOL(__ipipe_core_clock);
55
56unsigned long __ipipe_freq_scale;
57EXPORT_SYMBOL(__ipipe_freq_scale);
58
59atomic_t __ipipe_irq_lvdepth[IVG15 + 1];
60
61unsigned long __ipipe_irq_lvmask = __all_masked_irq_flags;
62EXPORT_SYMBOL(__ipipe_irq_lvmask);
63
64static void __ipipe_ack_irq(unsigned irq, struct irq_desc *desc)
65{
66 desc->ipipe_ack(irq, desc);
67}
68
69/*
70 * __ipipe_enable_pipeline() -- We are running on the boot CPU, hw
71 * interrupts are off, and secondary CPUs are still lost in space.
72 */
73void __ipipe_enable_pipeline(void)
74{
75 unsigned irq;
76
77 __ipipe_core_clock = get_cclk(); /* Fetch this once. */
78 __ipipe_freq_scale = 1000000000UL / __ipipe_core_clock;
79
80 for (irq = 0; irq < NR_IRQS; ++irq)
81 ipipe_virtualize_irq(ipipe_root_domain,
82 irq,
83 (ipipe_irq_handler_t)&asm_do_IRQ,
84 NULL,
85 &__ipipe_ack_irq,
86 IPIPE_HANDLE_MASK | IPIPE_PASS_MASK);
87}
88
89/*
90 * __ipipe_handle_irq() -- IPIPE's generic IRQ handler. An optimistic
91 * interrupt protection log is maintained here for each domain. Hw
92 * interrupts are masked on entry.
93 */
94void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs)
95{
96 struct ipipe_domain *this_domain, *next_domain;
97 struct list_head *head, *pos;
98 int m_ack, s = -1;
99
100 /*
101 * Software-triggered IRQs do not need any ack. The contents
102 * of the register frame should only be used when processing
103 * the timer interrupt, but not for handling any other
104 * interrupt.
105 */
106 m_ack = (regs == NULL || irq == IRQ_SYSTMR || irq == IRQ_CORETMR);
107
108 this_domain = ipipe_current_domain;
109
110 if (unlikely(test_bit(IPIPE_STICKY_FLAG, &this_domain->irqs[irq].control)))
111 head = &this_domain->p_link;
112 else {
113 head = __ipipe_pipeline.next;
114 next_domain = list_entry(head, struct ipipe_domain, p_link);
115 if (likely(test_bit(IPIPE_WIRED_FLAG, &next_domain->irqs[irq].control))) {
116 if (!m_ack && next_domain->irqs[irq].acknowledge != NULL)
117 next_domain->irqs[irq].acknowledge(irq, irq_desc + irq);
118 if (test_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags))
119 s = __test_and_set_bit(IPIPE_STALL_FLAG,
120 &ipipe_root_cpudom_var(status));
121 __ipipe_dispatch_wired(next_domain, irq);
122 goto finalize;
123 return;
124 }
125 }
126
127 /* Ack the interrupt. */
128
129 pos = head;
130
131 while (pos != &__ipipe_pipeline) {
132 next_domain = list_entry(pos, struct ipipe_domain, p_link);
133 /*
134 * For each domain handling the incoming IRQ, mark it
135 * as pending in its log.
136 */
137 if (test_bit(IPIPE_HANDLE_FLAG, &next_domain->irqs[irq].control)) {
138 /*
139 * Domains that handle this IRQ are polled for
140 * acknowledging it by decreasing priority
141 * order. The interrupt must be made pending
142 * _first_ in the domain's status flags before
143 * the PIC is unlocked.
144 */
145 __ipipe_set_irq_pending(next_domain, irq);
146
147 if (!m_ack && next_domain->irqs[irq].acknowledge != NULL) {
148 next_domain->irqs[irq].acknowledge(irq, irq_desc + irq);
149 m_ack = 1;
150 }
151 }
152
153 /*
154 * If the domain does not want the IRQ to be passed
155 * down the interrupt pipe, exit the loop now.
156 */
157 if (!test_bit(IPIPE_PASS_FLAG, &next_domain->irqs[irq].control))
158 break;
159
160 pos = next_domain->p_link.next;
161 }
162
163 /*
164 * Now walk the pipeline, yielding control to the highest
165 * priority domain that has pending interrupt(s) or
166 * immediately to the current domain if the interrupt has been
167 * marked as 'sticky'. This search does not go beyond the
168 * current domain in the pipeline. We also enforce the
169 * additional root stage lock (blackfin-specific). */
170
171 if (test_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags))
172 s = __test_and_set_bit(IPIPE_STALL_FLAG,
173 &ipipe_root_cpudom_var(status));
174finalize:
175
176 __ipipe_walk_pipeline(head);
177
178 if (!s)
179 __clear_bit(IPIPE_STALL_FLAG,
180 &ipipe_root_cpudom_var(status));
181}
182
183int __ipipe_check_root(void)
184{
185 return ipipe_root_domain_p;
186}
187
188void __ipipe_enable_irqdesc(struct ipipe_domain *ipd, unsigned irq)
189{
190 struct irq_desc *desc = irq_desc + irq;
191 int prio = desc->ic_prio;
192
193 desc->depth = 0;
194 if (ipd != &ipipe_root &&
195 atomic_inc_return(&__ipipe_irq_lvdepth[prio]) == 1)
196 __set_bit(prio, &__ipipe_irq_lvmask);
197}
198EXPORT_SYMBOL(__ipipe_enable_irqdesc);
199
200void __ipipe_disable_irqdesc(struct ipipe_domain *ipd, unsigned irq)
201{
202 struct irq_desc *desc = irq_desc + irq;
203 int prio = desc->ic_prio;
204
205 if (ipd != &ipipe_root &&
206 atomic_dec_and_test(&__ipipe_irq_lvdepth[prio]))
207 __clear_bit(prio, &__ipipe_irq_lvmask);
208}
209EXPORT_SYMBOL(__ipipe_disable_irqdesc);
210
211void __ipipe_stall_root_raw(void)
212{
213 /*
214 * This code is called by the ins{bwl} routines (see
215 * arch/blackfin/lib/ins.S), which are heavily used by the
216 * network stack. It masks all interrupts but those handled by
217 * non-root domains, so that we keep decent network transfer
218 * rates for Linux without inducing pathological jitter for
219 * the real-time domain.
220 */
221 __asm__ __volatile__ ("sti %0;" : : "d"(__ipipe_irq_lvmask));
222
223 __set_bit(IPIPE_STALL_FLAG,
224 &ipipe_root_cpudom_var(status));
225}
226
227void __ipipe_unstall_root_raw(void)
228{
229 __clear_bit(IPIPE_STALL_FLAG,
230 &ipipe_root_cpudom_var(status));
231
232 __asm__ __volatile__ ("sti %0;" : : "d"(bfin_irq_flags));
233}
234
235int __ipipe_syscall_root(struct pt_regs *regs)
236{
237 unsigned long flags;
238
239 /* We need to run the IRQ tail hook whenever we don't
240 * propagate a syscall to higher domains, because we know that
241 * important operations might be pending there (e.g. Xenomai
242 * deferred rescheduling). */
243
244 if (!__ipipe_syscall_watched_p(current, regs->orig_p0)) {
245 void (*hook)(void) = (void (*)(void))__ipipe_irq_tail_hook;
246 hook();
247 return 0;
248 }
249
250 /*
251 * This routine either returns:
252 * 0 -- if the syscall is to be passed to Linux;
253 * 1 -- if the syscall should not be passed to Linux, and no
254 * tail work should be performed;
255 * -1 -- if the syscall should not be passed to Linux but the
256 * tail work has to be performed (for handling signals etc).
257 */
258
259 if (__ipipe_event_monitored_p(IPIPE_EVENT_SYSCALL) &&
260 __ipipe_dispatch_event(IPIPE_EVENT_SYSCALL, regs) > 0) {
261 if (ipipe_root_domain_p && !in_atomic()) {
262 /*
263 * Sync pending VIRQs before _TIF_NEED_RESCHED
264 * is tested.
265 */
266 local_irq_save_hw(flags);
267 if ((ipipe_root_cpudom_var(irqpend_himask) & IPIPE_IRQMASK_VIRT) != 0)
268 __ipipe_sync_pipeline(IPIPE_IRQMASK_VIRT);
269 local_irq_restore_hw(flags);
270 return -1;
271 }
272 return 1;
273 }
274
275 return 0;
276}
277
278unsigned long ipipe_critical_enter(void (*syncfn) (void))
279{
280 unsigned long flags;
281
282 local_irq_save_hw(flags);
283
284 return flags;
285}
286
287void ipipe_critical_exit(unsigned long flags)
288{
289 local_irq_restore_hw(flags);
290}
291
292static void __ipipe_no_irqtail(void)
293{
294}
295
296int ipipe_get_sysinfo(struct ipipe_sysinfo *info)
297{
298 info->ncpus = num_online_cpus();
299 info->cpufreq = ipipe_cpu_freq();
300 info->archdep.tmirq = IPIPE_TIMER_IRQ;
301 info->archdep.tmfreq = info->cpufreq;
302
303 return 0;
304}
305
306/*
307 * ipipe_trigger_irq() -- Push the interrupt at front of the pipeline
308 * just like if it has been actually received from a hw source. Also
309 * works for virtual interrupts.
310 */
311int ipipe_trigger_irq(unsigned irq)
312{
313 unsigned long flags;
314
315 if (irq >= IPIPE_NR_IRQS ||
316 (ipipe_virtual_irq_p(irq)
317 && !test_bit(irq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map)))
318 return -EINVAL;
319
320 local_irq_save_hw(flags);
321
322 __ipipe_handle_irq(irq, NULL);
323
324 local_irq_restore_hw(flags);
325
326 return 1;
327}
328
329/* Move Linux IRQ to threads. */
330
331static int do_irqd(void *__desc)
332{
333 struct irq_desc *desc = __desc;
334 unsigned irq = desc - irq_desc;
335 int thrprio = desc->thr_prio;
336 int thrmask = 1 << thrprio;
337 int cpu = smp_processor_id();
338 cpumask_t cpumask;
339
340 sigfillset(&current->blocked);
341 current->flags |= PF_NOFREEZE;
342 cpumask = cpumask_of_cpu(cpu);
343 set_cpus_allowed(current, cpumask);
344 ipipe_setscheduler_root(current, SCHED_FIFO, 50 + thrprio);
345
346 while (!kthread_should_stop()) {
347 local_irq_disable();
348 if (!(desc->status & IRQ_SCHEDULED)) {
349 set_current_state(TASK_INTERRUPTIBLE);
350resched:
351 local_irq_enable();
352 schedule();
353 local_irq_disable();
354 }
355 __set_current_state(TASK_RUNNING);
356 /*
357 * If higher priority interrupt servers are ready to
358 * run, reschedule immediately. We need this for the
359 * GPIO demux IRQ handler to unmask the interrupt line
360 * _last_, after all GPIO IRQs have run.
361 */
362 if (per_cpu(pending_irqthread_mask, cpu) & ~(thrmask|(thrmask-1)))
363 goto resched;
364 if (--per_cpu(pending_irq_count[thrprio], cpu) == 0)
365 per_cpu(pending_irqthread_mask, cpu) &= ~thrmask;
366 desc->status &= ~IRQ_SCHEDULED;
367 desc->thr_handler(irq, &__raw_get_cpu_var(__ipipe_tick_regs));
368 local_irq_enable();
369 }
370 __set_current_state(TASK_RUNNING);
371 return 0;
372}
373
374static void kick_irqd(unsigned irq, void *cookie)
375{
376 struct irq_desc *desc = irq_desc + irq;
377 int thrprio = desc->thr_prio;
378 int thrmask = 1 << thrprio;
379 int cpu = smp_processor_id();
380
381 if (!(desc->status & IRQ_SCHEDULED)) {
382 desc->status |= IRQ_SCHEDULED;
383 per_cpu(pending_irqthread_mask, cpu) |= thrmask;
384 ++per_cpu(pending_irq_count[thrprio], cpu);
385 wake_up_process(desc->thread);
386 }
387}
388
389int ipipe_start_irq_thread(unsigned irq, struct irq_desc *desc)
390{
391 if (desc->thread || !create_irq_threads)
392 return 0;
393
394 desc->thread = kthread_create(do_irqd, desc, "IRQ %d", irq);
395 if (desc->thread == NULL) {
396 printk(KERN_ERR "irqd: could not create IRQ thread %d!\n", irq);
397 return -ENOMEM;
398 }
399
400 wake_up_process(desc->thread);
401
402 desc->thr_handler = ipipe_root_domain->irqs[irq].handler;
403 ipipe_root_domain->irqs[irq].handler = &kick_irqd;
404
405 return 0;
406}
407
408void __init ipipe_init_irq_threads(void)
409{
410 unsigned irq;
411 struct irq_desc *desc;
412
413 create_irq_threads = 1;
414
415 for (irq = 0; irq < NR_IRQS; irq++) {
416 desc = irq_desc + irq;
417 if (desc->action != NULL ||
418 (desc->status & IRQ_NOREQUEST) != 0)
419 ipipe_start_irq_thread(irq, desc);
420 }
421}
422
423EXPORT_SYMBOL(show_stack);
424
425#ifdef CONFIG_IPIPE_TRACE_MCOUNT
426void notrace _mcount(void);
427EXPORT_SYMBOL(_mcount);
428#endif /* CONFIG_IPIPE_TRACE_MCOUNT */