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6a01f230 YL |
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> | |
6a01f230 YL |
30 | #include <linux/errno.h> |
31 | #include <linux/kthread.h> | |
d8ca6395 PG |
32 | #include <linux/unistd.h> |
33 | #include <linux/io.h> | |
6a01f230 YL |
34 | #include <asm/system.h> |
35 | #include <asm/atomic.h> | |
6a01f230 | 36 | |
6a01f230 YL |
37 | DEFINE_PER_CPU(struct pt_regs, __ipipe_tick_regs); |
38 | ||
6a01f230 YL |
39 | asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs); |
40 | ||
41 | static void __ipipe_no_irqtail(void); | |
42 | ||
43 | unsigned long __ipipe_irq_tail_hook = (unsigned long)&__ipipe_no_irqtail; | |
44 | EXPORT_SYMBOL(__ipipe_irq_tail_hook); | |
45 | ||
46 | unsigned long __ipipe_core_clock; | |
47 | EXPORT_SYMBOL(__ipipe_core_clock); | |
48 | ||
49 | unsigned long __ipipe_freq_scale; | |
50 | EXPORT_SYMBOL(__ipipe_freq_scale); | |
51 | ||
52 | atomic_t __ipipe_irq_lvdepth[IVG15 + 1]; | |
53 | ||
06ecc190 | 54 | unsigned long __ipipe_irq_lvmask = bfin_no_irqs; |
6a01f230 YL |
55 | EXPORT_SYMBOL(__ipipe_irq_lvmask); |
56 | ||
57 | static void __ipipe_ack_irq(unsigned irq, struct irq_desc *desc) | |
58 | { | |
59 | desc->ipipe_ack(irq, desc); | |
60 | } | |
61 | ||
62 | /* | |
63 | * __ipipe_enable_pipeline() -- We are running on the boot CPU, hw | |
64 | * interrupts are off, and secondary CPUs are still lost in space. | |
65 | */ | |
66 | void __ipipe_enable_pipeline(void) | |
67 | { | |
68 | unsigned irq; | |
69 | ||
70 | __ipipe_core_clock = get_cclk(); /* Fetch this once. */ | |
71 | __ipipe_freq_scale = 1000000000UL / __ipipe_core_clock; | |
72 | ||
73 | for (irq = 0; irq < NR_IRQS; ++irq) | |
74 | ipipe_virtualize_irq(ipipe_root_domain, | |
75 | irq, | |
76 | (ipipe_irq_handler_t)&asm_do_IRQ, | |
77 | NULL, | |
78 | &__ipipe_ack_irq, | |
79 | IPIPE_HANDLE_MASK | IPIPE_PASS_MASK); | |
80 | } | |
81 | ||
82 | /* | |
83 | * __ipipe_handle_irq() -- IPIPE's generic IRQ handler. An optimistic | |
84 | * interrupt protection log is maintained here for each domain. Hw | |
85 | * interrupts are masked on entry. | |
86 | */ | |
87 | void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs) | |
88 | { | |
9bd50df6 | 89 | struct ipipe_percpu_domain_data *p = ipipe_root_cpudom_ptr(); |
6a01f230 YL |
90 | struct ipipe_domain *this_domain, *next_domain; |
91 | struct list_head *head, *pos; | |
d8ca6395 | 92 | struct ipipe_irqdesc *idesc; |
6a01f230 YL |
93 | int m_ack, s = -1; |
94 | ||
95 | /* | |
96 | * Software-triggered IRQs do not need any ack. The contents | |
97 | * of the register frame should only be used when processing | |
98 | * the timer interrupt, but not for handling any other | |
99 | * interrupt. | |
100 | */ | |
101 | m_ack = (regs == NULL || irq == IRQ_SYSTMR || irq == IRQ_CORETMR); | |
6640cfa8 | 102 | this_domain = __ipipe_current_domain; |
d8ca6395 | 103 | idesc = &this_domain->irqs[irq]; |
6a01f230 | 104 | |
d8ca6395 | 105 | if (unlikely(test_bit(IPIPE_STICKY_FLAG, &idesc->control))) |
6a01f230 YL |
106 | head = &this_domain->p_link; |
107 | else { | |
108 | head = __ipipe_pipeline.next; | |
109 | next_domain = list_entry(head, struct ipipe_domain, p_link); | |
d8ca6395 PG |
110 | idesc = &next_domain->irqs[irq]; |
111 | if (likely(test_bit(IPIPE_WIRED_FLAG, &idesc->control))) { | |
112 | if (!m_ack && idesc->acknowledge != NULL) | |
113 | idesc->acknowledge(irq, irq_to_desc(irq)); | |
9bd50df6 | 114 | if (test_bit(IPIPE_SYNCDEFER_FLAG, &p->status)) |
d8ca6395 PG |
115 | s = __test_and_set_bit(IPIPE_STALL_FLAG, |
116 | &p->status); | |
6a01f230 | 117 | __ipipe_dispatch_wired(next_domain, irq); |
9bd50df6 | 118 | goto out; |
6a01f230 YL |
119 | } |
120 | } | |
121 | ||
122 | /* Ack the interrupt. */ | |
123 | ||
124 | pos = head; | |
6a01f230 YL |
125 | while (pos != &__ipipe_pipeline) { |
126 | next_domain = list_entry(pos, struct ipipe_domain, p_link); | |
d8ca6395 PG |
127 | idesc = &next_domain->irqs[irq]; |
128 | if (test_bit(IPIPE_HANDLE_FLAG, &idesc->control)) { | |
6a01f230 | 129 | __ipipe_set_irq_pending(next_domain, irq); |
d8ca6395 PG |
130 | if (!m_ack && idesc->acknowledge != NULL) { |
131 | idesc->acknowledge(irq, irq_to_desc(irq)); | |
6a01f230 YL |
132 | m_ack = 1; |
133 | } | |
134 | } | |
d8ca6395 | 135 | if (!test_bit(IPIPE_PASS_FLAG, &idesc->control)) |
6a01f230 | 136 | break; |
6a01f230 YL |
137 | pos = next_domain->p_link.next; |
138 | } | |
139 | ||
140 | /* | |
141 | * Now walk the pipeline, yielding control to the highest | |
142 | * priority domain that has pending interrupt(s) or | |
143 | * immediately to the current domain if the interrupt has been | |
144 | * marked as 'sticky'. This search does not go beyond the | |
145 | * current domain in the pipeline. We also enforce the | |
9bd50df6 PG |
146 | * additional root stage lock (blackfin-specific). |
147 | */ | |
148 | if (test_bit(IPIPE_SYNCDEFER_FLAG, &p->status)) | |
149 | s = __test_and_set_bit(IPIPE_STALL_FLAG, &p->status); | |
6a01f230 | 150 | |
9bd50df6 PG |
151 | /* |
152 | * If the interrupt preempted the head domain, then do not | |
153 | * even try to walk the pipeline, unless an interrupt is | |
154 | * pending for it. | |
155 | */ | |
156 | if (test_bit(IPIPE_AHEAD_FLAG, &this_domain->flags) && | |
157 | ipipe_head_cpudom_var(irqpend_himask) == 0) | |
158 | goto out; | |
6a01f230 YL |
159 | |
160 | __ipipe_walk_pipeline(head); | |
9bd50df6 | 161 | out: |
6a01f230 | 162 | if (!s) |
9bd50df6 | 163 | __clear_bit(IPIPE_STALL_FLAG, &p->status); |
6a01f230 YL |
164 | } |
165 | ||
6a01f230 YL |
166 | void __ipipe_enable_irqdesc(struct ipipe_domain *ipd, unsigned irq) |
167 | { | |
9bd50df6 | 168 | struct irq_desc *desc = irq_to_desc(irq); |
51387009 | 169 | int prio = __ipipe_get_irq_priority(irq); |
6a01f230 YL |
170 | |
171 | desc->depth = 0; | |
172 | if (ipd != &ipipe_root && | |
173 | atomic_inc_return(&__ipipe_irq_lvdepth[prio]) == 1) | |
174 | __set_bit(prio, &__ipipe_irq_lvmask); | |
175 | } | |
176 | EXPORT_SYMBOL(__ipipe_enable_irqdesc); | |
177 | ||
178 | void __ipipe_disable_irqdesc(struct ipipe_domain *ipd, unsigned irq) | |
179 | { | |
51387009 | 180 | int prio = __ipipe_get_irq_priority(irq); |
6a01f230 YL |
181 | |
182 | if (ipd != &ipipe_root && | |
183 | atomic_dec_and_test(&__ipipe_irq_lvdepth[prio])) | |
184 | __clear_bit(prio, &__ipipe_irq_lvmask); | |
185 | } | |
186 | EXPORT_SYMBOL(__ipipe_disable_irqdesc); | |
187 | ||
6a01f230 YL |
188 | int __ipipe_syscall_root(struct pt_regs *regs) |
189 | { | |
6640cfa8 | 190 | struct ipipe_percpu_domain_data *p; |
6a01f230 | 191 | unsigned long flags; |
6640cfa8 | 192 | int ret; |
6a01f230 | 193 | |
9bd50df6 PG |
194 | /* |
195 | * We need to run the IRQ tail hook whenever we don't | |
6a01f230 YL |
196 | * propagate a syscall to higher domains, because we know that |
197 | * important operations might be pending there (e.g. Xenomai | |
9bd50df6 PG |
198 | * deferred rescheduling). |
199 | */ | |
6a01f230 | 200 | |
9bd50df6 | 201 | if (regs->orig_p0 < NR_syscalls) { |
6a01f230 YL |
202 | void (*hook)(void) = (void (*)(void))__ipipe_irq_tail_hook; |
203 | hook(); | |
9bd50df6 PG |
204 | if ((current->flags & PF_EVNOTIFY) == 0) |
205 | return 0; | |
6a01f230 YL |
206 | } |
207 | ||
208 | /* | |
209 | * This routine either returns: | |
210 | * 0 -- if the syscall is to be passed to Linux; | |
6640cfa8 | 211 | * >0 -- if the syscall should not be passed to Linux, and no |
6a01f230 | 212 | * tail work should be performed; |
6640cfa8 | 213 | * <0 -- if the syscall should not be passed to Linux but the |
6a01f230 YL |
214 | * tail work has to be performed (for handling signals etc). |
215 | */ | |
216 | ||
6640cfa8 YL |
217 | if (!__ipipe_event_monitored_p(IPIPE_EVENT_SYSCALL)) |
218 | return 0; | |
219 | ||
220 | ret = __ipipe_dispatch_event(IPIPE_EVENT_SYSCALL, regs); | |
221 | ||
222 | local_irq_save_hw(flags); | |
223 | ||
224 | if (!__ipipe_root_domain_p) { | |
225 | local_irq_restore_hw(flags); | |
6a01f230 YL |
226 | return 1; |
227 | } | |
228 | ||
6640cfa8 YL |
229 | p = ipipe_root_cpudom_ptr(); |
230 | if ((p->irqpend_himask & IPIPE_IRQMASK_VIRT) != 0) | |
231 | __ipipe_sync_pipeline(IPIPE_IRQMASK_VIRT); | |
232 | ||
233 | local_irq_restore_hw(flags); | |
234 | ||
235 | return -ret; | |
6a01f230 YL |
236 | } |
237 | ||
238 | unsigned long ipipe_critical_enter(void (*syncfn) (void)) | |
239 | { | |
240 | unsigned long flags; | |
241 | ||
242 | local_irq_save_hw(flags); | |
243 | ||
244 | return flags; | |
245 | } | |
246 | ||
247 | void ipipe_critical_exit(unsigned long flags) | |
248 | { | |
249 | local_irq_restore_hw(flags); | |
250 | } | |
251 | ||
252 | static void __ipipe_no_irqtail(void) | |
253 | { | |
254 | } | |
255 | ||
256 | int ipipe_get_sysinfo(struct ipipe_sysinfo *info) | |
257 | { | |
258 | info->ncpus = num_online_cpus(); | |
259 | info->cpufreq = ipipe_cpu_freq(); | |
260 | info->archdep.tmirq = IPIPE_TIMER_IRQ; | |
261 | info->archdep.tmfreq = info->cpufreq; | |
262 | ||
263 | return 0; | |
264 | } | |
265 | ||
266 | /* | |
267 | * ipipe_trigger_irq() -- Push the interrupt at front of the pipeline | |
268 | * just like if it has been actually received from a hw source. Also | |
269 | * works for virtual interrupts. | |
270 | */ | |
271 | int ipipe_trigger_irq(unsigned irq) | |
272 | { | |
273 | unsigned long flags; | |
274 | ||
9bd50df6 | 275 | #ifdef CONFIG_IPIPE_DEBUG |
6a01f230 YL |
276 | if (irq >= IPIPE_NR_IRQS || |
277 | (ipipe_virtual_irq_p(irq) | |
278 | && !test_bit(irq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map))) | |
279 | return -EINVAL; | |
9bd50df6 | 280 | #endif |
6a01f230 YL |
281 | |
282 | local_irq_save_hw(flags); | |
6a01f230 | 283 | __ipipe_handle_irq(irq, NULL); |
6a01f230 YL |
284 | local_irq_restore_hw(flags); |
285 | ||
286 | return 1; | |
287 | } | |
288 | ||
9bd50df6 | 289 | asmlinkage void __ipipe_sync_root(void) |
6a01f230 | 290 | { |
51387009 | 291 | void (*irq_tail_hook)(void) = (void (*)(void))__ipipe_irq_tail_hook; |
9bd50df6 | 292 | unsigned long flags; |
6a01f230 | 293 | |
9bd50df6 | 294 | BUG_ON(irqs_disabled()); |
6a01f230 | 295 | |
9bd50df6 | 296 | local_irq_save_hw(flags); |
6a01f230 | 297 | |
51387009 PG |
298 | if (irq_tail_hook) |
299 | irq_tail_hook(); | |
300 | ||
9bd50df6 | 301 | clear_thread_flag(TIF_IRQ_SYNC); |
6a01f230 | 302 | |
9bd50df6 PG |
303 | if (ipipe_root_cpudom_var(irqpend_himask) != 0) |
304 | __ipipe_sync_pipeline(IPIPE_IRQMASK_ANY); | |
6a01f230 | 305 | |
9bd50df6 | 306 | local_irq_restore_hw(flags); |
6a01f230 YL |
307 | } |
308 | ||
9bd50df6 | 309 | void ___ipipe_sync_pipeline(unsigned long syncmask) |
6a01f230 | 310 | { |
d8ca6395 PG |
311 | if (__ipipe_root_domain_p && |
312 | test_bit(IPIPE_SYNCDEFER_FLAG, &ipipe_root_cpudom_var(status))) | |
313 | return; | |
9bd50df6 PG |
314 | |
315 | __ipipe_sync_stage(syncmask); | |
6a01f230 | 316 | } |
b9c7eb49 PG |
317 | |
318 | void __ipipe_disable_root_irqs_hw(void) | |
319 | { | |
320 | /* | |
321 | * This code is called by the ins{bwl} routines (see | |
322 | * arch/blackfin/lib/ins.S), which are heavily used by the | |
323 | * network stack. It masks all interrupts but those handled by | |
324 | * non-root domains, so that we keep decent network transfer | |
325 | * rates for Linux without inducing pathological jitter for | |
326 | * the real-time domain. | |
327 | */ | |
328 | bfin_sti(__ipipe_irq_lvmask); | |
329 | __set_bit(IPIPE_STALL_FLAG, &ipipe_root_cpudom_var(status)); | |
330 | } | |
331 | ||
332 | void __ipipe_enable_root_irqs_hw(void) | |
333 | { | |
334 | __clear_bit(IPIPE_STALL_FLAG, &ipipe_root_cpudom_var(status)); | |
335 | bfin_sti(bfin_irq_flags); | |
336 | } | |
d2685fb7 PG |
337 | |
338 | /* | |
339 | * We could use standard atomic bitops in the following root status | |
340 | * manipulation routines, but let's prepare for SMP support in the | |
341 | * same move, preventing CPU migration as required. | |
342 | */ | |
343 | void __ipipe_stall_root(void) | |
344 | { | |
345 | unsigned long *p, flags; | |
346 | ||
347 | local_irq_save_hw(flags); | |
348 | p = &__ipipe_root_status; | |
349 | __set_bit(IPIPE_STALL_FLAG, p); | |
350 | local_irq_restore_hw(flags); | |
351 | } | |
352 | EXPORT_SYMBOL(__ipipe_stall_root); | |
353 | ||
354 | unsigned long __ipipe_test_and_stall_root(void) | |
355 | { | |
356 | unsigned long *p, flags; | |
357 | int x; | |
358 | ||
359 | local_irq_save_hw(flags); | |
360 | p = &__ipipe_root_status; | |
361 | x = __test_and_set_bit(IPIPE_STALL_FLAG, p); | |
362 | local_irq_restore_hw(flags); | |
363 | ||
364 | return x; | |
365 | } | |
366 | EXPORT_SYMBOL(__ipipe_test_and_stall_root); | |
367 | ||
368 | unsigned long __ipipe_test_root(void) | |
369 | { | |
370 | const unsigned long *p; | |
371 | unsigned long flags; | |
372 | int x; | |
373 | ||
374 | local_irq_save_hw_smp(flags); | |
375 | p = &__ipipe_root_status; | |
376 | x = test_bit(IPIPE_STALL_FLAG, p); | |
377 | local_irq_restore_hw_smp(flags); | |
378 | ||
379 | return x; | |
380 | } | |
381 | EXPORT_SYMBOL(__ipipe_test_root); | |
382 | ||
383 | void __ipipe_lock_root(void) | |
384 | { | |
385 | unsigned long *p, flags; | |
386 | ||
387 | local_irq_save_hw(flags); | |
388 | p = &__ipipe_root_status; | |
389 | __set_bit(IPIPE_SYNCDEFER_FLAG, p); | |
390 | local_irq_restore_hw(flags); | |
391 | } | |
392 | EXPORT_SYMBOL(__ipipe_lock_root); | |
393 | ||
394 | void __ipipe_unlock_root(void) | |
395 | { | |
396 | unsigned long *p, flags; | |
397 | ||
398 | local_irq_save_hw(flags); | |
399 | p = &__ipipe_root_status; | |
400 | __clear_bit(IPIPE_SYNCDEFER_FLAG, p); | |
401 | local_irq_restore_hw(flags); | |
402 | } | |
403 | EXPORT_SYMBOL(__ipipe_unlock_root); |