atomic: use <linux/atomic.h>
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / x86 / kernel / i8259.c
CommitLineData
21fd5132 1#include <linux/linkage.h>
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2#include <linux/errno.h>
3#include <linux/signal.h>
4#include <linux/sched.h>
5#include <linux/ioport.h>
6#include <linux/interrupt.h>
21fd5132 7#include <linux/timex.h>
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8#include <linux/random.h>
9#include <linux/init.h>
10#include <linux/kernel_stat.h>
f3c6ea1b 11#include <linux/syscore_ops.h>
21fd5132 12#include <linux/bitops.h>
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13#include <linux/acpi.h>
14#include <linux/io.h>
15#include <linux/delay.h>
21fd5132 16
60063497 17#include <linux/atomic.h>
21fd5132 18#include <asm/system.h>
21fd5132 19#include <asm/timer.h>
21fd5132 20#include <asm/hw_irq.h>
21fd5132 21#include <asm/pgtable.h>
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22#include <asm/desc.h>
23#include <asm/apic.h>
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24#include <asm/i8259.h>
25
26/*
27 * This is the 'legacy' 8259A Programmable Interrupt Controller,
28 * present in the majority of PC/AT boxes.
29 * plus some generic x86 specific things if generic specifics makes
30 * any sense at all.
31 */
4305df94 32static void init_8259A(int auto_eoi);
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33
34static int i8259A_auto_eoi;
5619c280 35DEFINE_RAW_SPINLOCK(i8259A_lock);
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36
37/*
38 * 8259A PIC functions to handle ISA devices:
39 */
40
41/*
42 * This contains the irq mask for both 8259A irq controllers,
43 */
44unsigned int cached_irq_mask = 0xffff;
45
46/*
47 * Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
48 * boards the timer interrupt is not really connected to any IO-APIC pin,
49 * it's fed to the master 8259A's IR0 line only.
50 *
51 * Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
52 * this 'mixed mode' IRQ handling costs nothing because it's only used
53 * at IRQ setup time.
54 */
55unsigned long io_apic_irqs;
56
4305df94 57static void mask_8259A_irq(unsigned int irq)
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58{
59 unsigned int mask = 1 << irq;
60 unsigned long flags;
61
5619c280 62 raw_spin_lock_irqsave(&i8259A_lock, flags);
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63 cached_irq_mask |= mask;
64 if (irq & 8)
65 outb(cached_slave_mask, PIC_SLAVE_IMR);
66 else
67 outb(cached_master_mask, PIC_MASTER_IMR);
5619c280 68 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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69}
70
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71static void disable_8259A_irq(struct irq_data *data)
72{
73 mask_8259A_irq(data->irq);
74}
75
76static void unmask_8259A_irq(unsigned int irq)
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77{
78 unsigned int mask = ~(1 << irq);
79 unsigned long flags;
80
5619c280 81 raw_spin_lock_irqsave(&i8259A_lock, flags);
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82 cached_irq_mask &= mask;
83 if (irq & 8)
84 outb(cached_slave_mask, PIC_SLAVE_IMR);
85 else
86 outb(cached_master_mask, PIC_MASTER_IMR);
5619c280 87 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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88}
89
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90static void enable_8259A_irq(struct irq_data *data)
91{
92 unmask_8259A_irq(data->irq);
93}
94
b81bb373 95static int i8259A_irq_pending(unsigned int irq)
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96{
97 unsigned int mask = 1<<irq;
98 unsigned long flags;
99 int ret;
100
5619c280 101 raw_spin_lock_irqsave(&i8259A_lock, flags);
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102 if (irq < 8)
103 ret = inb(PIC_MASTER_CMD) & mask;
104 else
105 ret = inb(PIC_SLAVE_CMD) & (mask >> 8);
5619c280 106 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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107
108 return ret;
109}
110
b81bb373 111static void make_8259A_irq(unsigned int irq)
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112{
113 disable_irq_nosync(irq);
114 io_apic_irqs &= ~(1<<irq);
2c778651 115 irq_set_chip_and_handler_name(irq, &i8259A_chip, handle_level_irq,
4305df94 116 i8259A_chip.name);
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117 enable_irq(irq);
118}
119
120/*
121 * This function assumes to be called rarely. Switching between
122 * 8259A registers is slow.
123 * This has to be protected by the irq controller spinlock
124 * before being called.
125 */
126static inline int i8259A_irq_real(unsigned int irq)
127{
128 int value;
129 int irqmask = 1<<irq;
130
131 if (irq < 8) {
680afbf9 132 outb(0x0B, PIC_MASTER_CMD); /* ISR register */
21fd5132 133 value = inb(PIC_MASTER_CMD) & irqmask;
680afbf9 134 outb(0x0A, PIC_MASTER_CMD); /* back to the IRR register */
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135 return value;
136 }
680afbf9 137 outb(0x0B, PIC_SLAVE_CMD); /* ISR register */
21fd5132 138 value = inb(PIC_SLAVE_CMD) & (irqmask >> 8);
680afbf9 139 outb(0x0A, PIC_SLAVE_CMD); /* back to the IRR register */
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140 return value;
141}
142
143/*
144 * Careful! The 8259A is a fragile beast, it pretty
145 * much _has_ to be done exactly like this (mask it
146 * first, _then_ send the EOI, and the order of EOI
147 * to the two 8259s is important!
148 */
4305df94 149static void mask_and_ack_8259A(struct irq_data *data)
21fd5132 150{
4305df94 151 unsigned int irq = data->irq;
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152 unsigned int irqmask = 1 << irq;
153 unsigned long flags;
154
5619c280 155 raw_spin_lock_irqsave(&i8259A_lock, flags);
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156 /*
157 * Lightweight spurious IRQ detection. We do not want
158 * to overdo spurious IRQ handling - it's usually a sign
159 * of hardware problems, so we only do the checks we can
160 * do without slowing down good hardware unnecessarily.
161 *
162 * Note that IRQ7 and IRQ15 (the two spurious IRQs
163 * usually resulting from the 8259A-1|2 PICs) occur
164 * even if the IRQ is masked in the 8259A. Thus we
165 * can check spurious 8259A IRQs without doing the
166 * quite slow i8259A_irq_real() call for every IRQ.
167 * This does not cover 100% of spurious interrupts,
168 * but should be enough to warn the user that there
169 * is something bad going on ...
170 */
171 if (cached_irq_mask & irqmask)
172 goto spurious_8259A_irq;
173 cached_irq_mask |= irqmask;
174
175handle_real_irq:
176 if (irq & 8) {
177 inb(PIC_SLAVE_IMR); /* DUMMY - (do we need this?) */
178 outb(cached_slave_mask, PIC_SLAVE_IMR);
21fd5132 179 /* 'Specific EOI' to slave */
3e8631d2 180 outb(0x60+(irq&7), PIC_SLAVE_CMD);
21fd5132 181 /* 'Specific EOI' to master-IRQ2 */
3e8631d2 182 outb(0x60+PIC_CASCADE_IR, PIC_MASTER_CMD);
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183 } else {
184 inb(PIC_MASTER_IMR); /* DUMMY - (do we need this?) */
185 outb(cached_master_mask, PIC_MASTER_IMR);
3e8631d2 186 outb(0x60+irq, PIC_MASTER_CMD); /* 'Specific EOI to master */
21fd5132 187 }
5619c280 188 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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189 return;
190
191spurious_8259A_irq:
192 /*
193 * this is the slow path - should happen rarely.
194 */
195 if (i8259A_irq_real(irq))
196 /*
197 * oops, the IRQ _is_ in service according to the
198 * 8259A - not spurious, go handle it.
199 */
200 goto handle_real_irq;
201
202 {
203 static int spurious_irq_mask;
204 /*
205 * At this point we can be sure the IRQ is spurious,
206 * lets ACK and report it. [once per IRQ]
207 */
208 if (!(spurious_irq_mask & irqmask)) {
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209 printk(KERN_DEBUG
210 "spurious 8259A interrupt: IRQ%d.\n", irq);
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211 spurious_irq_mask |= irqmask;
212 }
213 atomic_inc(&irq_err_count);
214 /*
215 * Theoretically we do not have to handle this IRQ,
216 * but in Linux this does not cause problems and is
217 * simpler for us.
218 */
219 goto handle_real_irq;
220 }
221}
222
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223struct irq_chip i8259A_chip = {
224 .name = "XT-PIC",
225 .irq_mask = disable_8259A_irq,
226 .irq_disable = disable_8259A_irq,
227 .irq_unmask = enable_8259A_irq,
228 .irq_mask_ack = mask_and_ack_8259A,
229};
230
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231static char irq_trigger[2];
232/**
233 * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
234 */
235static void restore_ELCR(char *trigger)
236{
237 outb(trigger[0], 0x4d0);
238 outb(trigger[1], 0x4d1);
239}
240
241static void save_ELCR(char *trigger)
242{
243 /* IRQ 0,1,2,8,13 are marked as reserved */
244 trigger[0] = inb(0x4d0) & 0xF8;
245 trigger[1] = inb(0x4d1) & 0xDE;
246}
247
f3c6ea1b 248static void i8259A_resume(void)
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249{
250 init_8259A(i8259A_auto_eoi);
251 restore_ELCR(irq_trigger);
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252}
253
f3c6ea1b 254static int i8259A_suspend(void)
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255{
256 save_ELCR(irq_trigger);
257 return 0;
258}
259
f3c6ea1b 260static void i8259A_shutdown(void)
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261{
262 /* Put the i8259A into a quiescent state that
263 * the kernel initialization code can get it
264 * out of.
265 */
266 outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
267 outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-1 */
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268}
269
f3c6ea1b 270static struct syscore_ops i8259_syscore_ops = {
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271 .suspend = i8259A_suspend,
272 .resume = i8259A_resume,
273 .shutdown = i8259A_shutdown,
274};
275
b81bb373 276static void mask_8259A(void)
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277{
278 unsigned long flags;
279
5619c280 280 raw_spin_lock_irqsave(&i8259A_lock, flags);
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281
282 outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
283 outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */
284
5619c280 285 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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286}
287
b81bb373 288static void unmask_8259A(void)
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289{
290 unsigned long flags;
291
5619c280 292 raw_spin_lock_irqsave(&i8259A_lock, flags);
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293
294 outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
295 outb(cached_slave_mask, PIC_SLAVE_IMR); /* restore slave IRQ mask */
296
5619c280 297 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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298}
299
b81bb373 300static void init_8259A(int auto_eoi)
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301{
302 unsigned long flags;
303
304 i8259A_auto_eoi = auto_eoi;
305
5619c280 306 raw_spin_lock_irqsave(&i8259A_lock, flags);
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307
308 outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
309 outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */
310
311 /*
312 * outb_pic - this has to work on a wide range of PC hardware.
313 */
314 outb_pic(0x11, PIC_MASTER_CMD); /* ICW1: select 8259A-1 init */
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315
316 /* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 on x86-64,
7bafaf30 317 to 0x20-0x27 on i386 */
21fd5132 318 outb_pic(IRQ0_VECTOR, PIC_MASTER_IMR);
c46e62f7 319
21fd5132 320 /* 8259A-1 (the master) has a slave on IR2 */
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321 outb_pic(1U << PIC_CASCADE_IR, PIC_MASTER_IMR);
322
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323 if (auto_eoi) /* master does Auto EOI */
324 outb_pic(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR);
325 else /* master expects normal EOI */
326 outb_pic(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR);
327
328 outb_pic(0x11, PIC_SLAVE_CMD); /* ICW1: select 8259A-2 init */
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329
330 /* ICW2: 8259A-2 IR0-7 mapped to IRQ8_VECTOR */
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331 outb_pic(IRQ8_VECTOR, PIC_SLAVE_IMR);
332 /* 8259A-2 is a slave on master's IR2 */
333 outb_pic(PIC_CASCADE_IR, PIC_SLAVE_IMR);
334 /* (slave's support for AEOI in flat mode is to be investigated) */
335 outb_pic(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR);
336
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337 if (auto_eoi)
338 /*
339 * In AEOI mode we just have to mask the interrupt
340 * when acking.
341 */
4305df94 342 i8259A_chip.irq_mask_ack = disable_8259A_irq;
21fd5132 343 else
4305df94 344 i8259A_chip.irq_mask_ack = mask_and_ack_8259A;
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345
346 udelay(100); /* wait for 8259A to initialize */
347
348 outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
349 outb(cached_slave_mask, PIC_SLAVE_IMR); /* restore slave IRQ mask */
350
5619c280 351 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
21fd5132 352}
b81bb373 353
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354/*
355 * make i8259 a driver so that we can select pic functions at run time. the goal
356 * is to make x86 binary compatible among pc compatible and non-pc compatible
357 * platforms, such as x86 MID.
358 */
359
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360static void legacy_pic_noop(void) { };
361static void legacy_pic_uint_noop(unsigned int unused) { };
362static void legacy_pic_int_noop(int unused) { };
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363static int legacy_pic_irq_pending_noop(unsigned int irq)
364{
365 return 0;
366}
367
368struct legacy_pic null_legacy_pic = {
369 .nr_legacy_irqs = 0,
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370 .chip = &dummy_irq_chip,
371 .mask = legacy_pic_uint_noop,
372 .unmask = legacy_pic_uint_noop,
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373 .mask_all = legacy_pic_noop,
374 .restore_mask = legacy_pic_noop,
375 .init = legacy_pic_int_noop,
376 .irq_pending = legacy_pic_irq_pending_noop,
377 .make_irq = legacy_pic_uint_noop,
378};
379
380struct legacy_pic default_legacy_pic = {
381 .nr_legacy_irqs = NR_IRQS_LEGACY,
382 .chip = &i8259A_chip,
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383 .mask = mask_8259A_irq,
384 .unmask = unmask_8259A_irq,
385 .mask_all = mask_8259A,
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386 .restore_mask = unmask_8259A,
387 .init = init_8259A,
388 .irq_pending = i8259A_irq_pending,
389 .make_irq = make_8259A_irq,
390};
391
392struct legacy_pic *legacy_pic = &default_legacy_pic;
087b255a 393
f3c6ea1b 394static int __init i8259A_init_ops(void)
087b255a 395{
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396 if (legacy_pic == &default_legacy_pic)
397 register_syscore_ops(&i8259_syscore_ops);
087b255a 398
f3c6ea1b 399 return 0;
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400}
401
f3c6ea1b 402device_initcall(i8259A_init_ops);