include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[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>
11#include <linux/sysdev.h>
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
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17#include <asm/atomic.h>
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 */
32
33static int i8259A_auto_eoi;
5619c280 34DEFINE_RAW_SPINLOCK(i8259A_lock);
21fd5132 35static void mask_and_ack_8259A(unsigned int);
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36static void mask_8259A(void);
37static void unmask_8259A(void);
38static void disable_8259A_irq(unsigned int irq);
39static void enable_8259A_irq(unsigned int irq);
40static void init_8259A(int auto_eoi);
41static int i8259A_irq_pending(unsigned int irq);
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42
43struct irq_chip i8259A_chip = {
44 .name = "XT-PIC",
45 .mask = disable_8259A_irq,
46 .disable = disable_8259A_irq,
47 .unmask = enable_8259A_irq,
48 .mask_ack = mask_and_ack_8259A,
49};
50
51/*
52 * 8259A PIC functions to handle ISA devices:
53 */
54
55/*
56 * This contains the irq mask for both 8259A irq controllers,
57 */
58unsigned int cached_irq_mask = 0xffff;
59
60/*
61 * Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
62 * boards the timer interrupt is not really connected to any IO-APIC pin,
63 * it's fed to the master 8259A's IR0 line only.
64 *
65 * Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
66 * this 'mixed mode' IRQ handling costs nothing because it's only used
67 * at IRQ setup time.
68 */
69unsigned long io_apic_irqs;
70
b81bb373 71static void disable_8259A_irq(unsigned int irq)
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72{
73 unsigned int mask = 1 << irq;
74 unsigned long flags;
75
5619c280 76 raw_spin_lock_irqsave(&i8259A_lock, flags);
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77 cached_irq_mask |= mask;
78 if (irq & 8)
79 outb(cached_slave_mask, PIC_SLAVE_IMR);
80 else
81 outb(cached_master_mask, PIC_MASTER_IMR);
5619c280 82 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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83}
84
b81bb373 85static void enable_8259A_irq(unsigned int irq)
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86{
87 unsigned int mask = ~(1 << irq);
88 unsigned long flags;
89
5619c280 90 raw_spin_lock_irqsave(&i8259A_lock, flags);
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91 cached_irq_mask &= mask;
92 if (irq & 8)
93 outb(cached_slave_mask, PIC_SLAVE_IMR);
94 else
95 outb(cached_master_mask, PIC_MASTER_IMR);
5619c280 96 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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97}
98
b81bb373 99static int i8259A_irq_pending(unsigned int irq)
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100{
101 unsigned int mask = 1<<irq;
102 unsigned long flags;
103 int ret;
104
5619c280 105 raw_spin_lock_irqsave(&i8259A_lock, flags);
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106 if (irq < 8)
107 ret = inb(PIC_MASTER_CMD) & mask;
108 else
109 ret = inb(PIC_SLAVE_CMD) & (mask >> 8);
5619c280 110 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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111
112 return ret;
113}
114
b81bb373 115static void make_8259A_irq(unsigned int irq)
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116{
117 disable_irq_nosync(irq);
118 io_apic_irqs &= ~(1<<irq);
119 set_irq_chip_and_handler_name(irq, &i8259A_chip, handle_level_irq,
120 "XT");
121 enable_irq(irq);
122}
123
124/*
125 * This function assumes to be called rarely. Switching between
126 * 8259A registers is slow.
127 * This has to be protected by the irq controller spinlock
128 * before being called.
129 */
130static inline int i8259A_irq_real(unsigned int irq)
131{
132 int value;
133 int irqmask = 1<<irq;
134
135 if (irq < 8) {
680afbf9 136 outb(0x0B, PIC_MASTER_CMD); /* ISR register */
21fd5132 137 value = inb(PIC_MASTER_CMD) & irqmask;
680afbf9 138 outb(0x0A, PIC_MASTER_CMD); /* back to the IRR register */
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139 return value;
140 }
680afbf9 141 outb(0x0B, PIC_SLAVE_CMD); /* ISR register */
21fd5132 142 value = inb(PIC_SLAVE_CMD) & (irqmask >> 8);
680afbf9 143 outb(0x0A, PIC_SLAVE_CMD); /* back to the IRR register */
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144 return value;
145}
146
147/*
148 * Careful! The 8259A is a fragile beast, it pretty
149 * much _has_ to be done exactly like this (mask it
150 * first, _then_ send the EOI, and the order of EOI
151 * to the two 8259s is important!
152 */
153static void mask_and_ack_8259A(unsigned int irq)
154{
155 unsigned int irqmask = 1 << irq;
156 unsigned long flags;
157
5619c280 158 raw_spin_lock_irqsave(&i8259A_lock, flags);
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159 /*
160 * Lightweight spurious IRQ detection. We do not want
161 * to overdo spurious IRQ handling - it's usually a sign
162 * of hardware problems, so we only do the checks we can
163 * do without slowing down good hardware unnecessarily.
164 *
165 * Note that IRQ7 and IRQ15 (the two spurious IRQs
166 * usually resulting from the 8259A-1|2 PICs) occur
167 * even if the IRQ is masked in the 8259A. Thus we
168 * can check spurious 8259A IRQs without doing the
169 * quite slow i8259A_irq_real() call for every IRQ.
170 * This does not cover 100% of spurious interrupts,
171 * but should be enough to warn the user that there
172 * is something bad going on ...
173 */
174 if (cached_irq_mask & irqmask)
175 goto spurious_8259A_irq;
176 cached_irq_mask |= irqmask;
177
178handle_real_irq:
179 if (irq & 8) {
180 inb(PIC_SLAVE_IMR); /* DUMMY - (do we need this?) */
181 outb(cached_slave_mask, PIC_SLAVE_IMR);
21fd5132 182 /* 'Specific EOI' to slave */
3e8631d2 183 outb(0x60+(irq&7), PIC_SLAVE_CMD);
21fd5132 184 /* 'Specific EOI' to master-IRQ2 */
3e8631d2 185 outb(0x60+PIC_CASCADE_IR, PIC_MASTER_CMD);
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186 } else {
187 inb(PIC_MASTER_IMR); /* DUMMY - (do we need this?) */
188 outb(cached_master_mask, PIC_MASTER_IMR);
3e8631d2 189 outb(0x60+irq, PIC_MASTER_CMD); /* 'Specific EOI to master */
21fd5132 190 }
5619c280 191 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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192 return;
193
194spurious_8259A_irq:
195 /*
196 * this is the slow path - should happen rarely.
197 */
198 if (i8259A_irq_real(irq))
199 /*
200 * oops, the IRQ _is_ in service according to the
201 * 8259A - not spurious, go handle it.
202 */
203 goto handle_real_irq;
204
205 {
206 static int spurious_irq_mask;
207 /*
208 * At this point we can be sure the IRQ is spurious,
209 * lets ACK and report it. [once per IRQ]
210 */
211 if (!(spurious_irq_mask & irqmask)) {
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212 printk(KERN_DEBUG
213 "spurious 8259A interrupt: IRQ%d.\n", irq);
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214 spurious_irq_mask |= irqmask;
215 }
216 atomic_inc(&irq_err_count);
217 /*
218 * Theoretically we do not have to handle this IRQ,
219 * but in Linux this does not cause problems and is
220 * simpler for us.
221 */
222 goto handle_real_irq;
223 }
224}
225
226static char irq_trigger[2];
227/**
228 * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
229 */
230static void restore_ELCR(char *trigger)
231{
232 outb(trigger[0], 0x4d0);
233 outb(trigger[1], 0x4d1);
234}
235
236static void save_ELCR(char *trigger)
237{
238 /* IRQ 0,1,2,8,13 are marked as reserved */
239 trigger[0] = inb(0x4d0) & 0xF8;
240 trigger[1] = inb(0x4d1) & 0xDE;
241}
242
243static int i8259A_resume(struct sys_device *dev)
244{
245 init_8259A(i8259A_auto_eoi);
246 restore_ELCR(irq_trigger);
247 return 0;
248}
249
250static int i8259A_suspend(struct sys_device *dev, pm_message_t state)
251{
252 save_ELCR(irq_trigger);
253 return 0;
254}
255
256static int i8259A_shutdown(struct sys_device *dev)
257{
258 /* Put the i8259A into a quiescent state that
259 * the kernel initialization code can get it
260 * out of.
261 */
262 outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
263 outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-1 */
264 return 0;
265}
266
267static struct sysdev_class i8259_sysdev_class = {
268 .name = "i8259",
269 .suspend = i8259A_suspend,
270 .resume = i8259A_resume,
271 .shutdown = i8259A_shutdown,
272};
273
274static struct sys_device device_i8259A = {
275 .id = 0,
276 .cls = &i8259_sysdev_class,
277};
278
279static int __init i8259A_init_sysfs(void)
280{
281 int error = sysdev_class_register(&i8259_sysdev_class);
282 if (!error)
283 error = sysdev_register(&device_i8259A);
284 return error;
285}
286
287device_initcall(i8259A_init_sysfs);
288
b81bb373 289static void mask_8259A(void)
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290{
291 unsigned long flags;
292
5619c280 293 raw_spin_lock_irqsave(&i8259A_lock, flags);
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294
295 outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
296 outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */
297
5619c280 298 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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299}
300
b81bb373 301static void unmask_8259A(void)
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302{
303 unsigned long flags;
304
5619c280 305 raw_spin_lock_irqsave(&i8259A_lock, flags);
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306
307 outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
308 outb(cached_slave_mask, PIC_SLAVE_IMR); /* restore slave IRQ mask */
309
5619c280 310 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
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311}
312
b81bb373 313static void init_8259A(int auto_eoi)
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314{
315 unsigned long flags;
316
317 i8259A_auto_eoi = auto_eoi;
318
5619c280 319 raw_spin_lock_irqsave(&i8259A_lock, flags);
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320
321 outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
322 outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */
323
324 /*
325 * outb_pic - this has to work on a wide range of PC hardware.
326 */
327 outb_pic(0x11, PIC_MASTER_CMD); /* ICW1: select 8259A-1 init */
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328
329 /* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 on x86-64,
7bafaf30 330 to 0x20-0x27 on i386 */
21fd5132 331 outb_pic(IRQ0_VECTOR, PIC_MASTER_IMR);
c46e62f7 332
21fd5132 333 /* 8259A-1 (the master) has a slave on IR2 */
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334 outb_pic(1U << PIC_CASCADE_IR, PIC_MASTER_IMR);
335
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336 if (auto_eoi) /* master does Auto EOI */
337 outb_pic(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR);
338 else /* master expects normal EOI */
339 outb_pic(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR);
340
341 outb_pic(0x11, PIC_SLAVE_CMD); /* ICW1: select 8259A-2 init */
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342
343 /* ICW2: 8259A-2 IR0-7 mapped to IRQ8_VECTOR */
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344 outb_pic(IRQ8_VECTOR, PIC_SLAVE_IMR);
345 /* 8259A-2 is a slave on master's IR2 */
346 outb_pic(PIC_CASCADE_IR, PIC_SLAVE_IMR);
347 /* (slave's support for AEOI in flat mode is to be investigated) */
348 outb_pic(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR);
349
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350 if (auto_eoi)
351 /*
352 * In AEOI mode we just have to mask the interrupt
353 * when acking.
354 */
355 i8259A_chip.mask_ack = disable_8259A_irq;
356 else
357 i8259A_chip.mask_ack = mask_and_ack_8259A;
358
359 udelay(100); /* wait for 8259A to initialize */
360
361 outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
362 outb(cached_slave_mask, PIC_SLAVE_IMR); /* restore slave IRQ mask */
363
5619c280 364 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
21fd5132 365}
b81bb373 366
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367/*
368 * make i8259 a driver so that we can select pic functions at run time. the goal
369 * is to make x86 binary compatible among pc compatible and non-pc compatible
370 * platforms, such as x86 MID.
371 */
372
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373static void legacy_pic_noop(void) { };
374static void legacy_pic_uint_noop(unsigned int unused) { };
375static void legacy_pic_int_noop(int unused) { };
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376
377static struct irq_chip dummy_pic_chip = {
378 .name = "dummy pic",
379 .mask = legacy_pic_uint_noop,
380 .unmask = legacy_pic_uint_noop,
381 .disable = legacy_pic_uint_noop,
382 .mask_ack = legacy_pic_uint_noop,
383};
384static int legacy_pic_irq_pending_noop(unsigned int irq)
385{
386 return 0;
387}
388
389struct legacy_pic null_legacy_pic = {
390 .nr_legacy_irqs = 0,
391 .chip = &dummy_pic_chip,
392 .mask_all = legacy_pic_noop,
393 .restore_mask = legacy_pic_noop,
394 .init = legacy_pic_int_noop,
395 .irq_pending = legacy_pic_irq_pending_noop,
396 .make_irq = legacy_pic_uint_noop,
397};
398
399struct legacy_pic default_legacy_pic = {
400 .nr_legacy_irqs = NR_IRQS_LEGACY,
401 .chip = &i8259A_chip,
402 .mask_all = mask_8259A,
403 .restore_mask = unmask_8259A,
404 .init = init_8259A,
405 .irq_pending = i8259A_irq_pending,
406 .make_irq = make_8259A_irq,
407};
408
409struct legacy_pic *legacy_pic = &default_legacy_pic;