summaryrefslogtreecommitdiffstats
path: root/arch/ia64/kernel/irq_ia64.c
blob: 456f57b087ca78c9b3ddbc7244b125a6657ef8fa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
/*
 * linux/arch/ia64/kernel/irq_ia64.c
 *
 * Copyright (C) 1998-2001 Hewlett-Packard Co
 *	Stephane Eranian <eranian@hpl.hp.com>
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 *
 *  6/10/99: Updated to bring in sync with x86 version to facilitate
 *	     support for SMP and different interrupt controllers.
 *
 * 09/15/00 Goutham Rao <goutham.rao@intel.com> Implemented pci_irq_to_vector
 *                      PCI to vector allocation routine.
 * 04/14/2004 Ashok Raj <ashok.raj@intel.com>
 *						Added CPU Hotplug handling for IPF.
 */

#include <linux/module.h>

#include <linux/jiffies.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/kernel_stat.h>
#include <linux/slab.h>
#include <linux/ptrace.h>
#include <linux/random.h>	/* for rand_initialize_irq() */
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/threads.h>
#include <linux/bitops.h>
#include <linux/irq.h>

#include <asm/delay.h>
#include <asm/intrinsics.h>
#include <asm/io.h>
#include <asm/hw_irq.h>
#include <asm/machvec.h>
#include <asm/pgtable.h>
#include <asm/system.h>

#ifdef CONFIG_PERFMON
# include <asm/perfmon.h>
#endif

#define IRQ_DEBUG	0

/* These can be overridden in platform_irq_init */
int ia64_first_device_vector = IA64_DEF_FIRST_DEVICE_VECTOR;
int ia64_last_device_vector = IA64_DEF_LAST_DEVICE_VECTOR;

/* default base addr of IPI table */
void __iomem *ipi_base_addr = ((void __iomem *)
			       (__IA64_UNCACHED_OFFSET | IA64_IPI_DEFAULT_BASE_ADDR));

/*
 * Legacy IRQ to IA-64 vector translation table.
 */
__u8 isa_irq_to_vector_map[16] = {
	/* 8259 IRQ translation, first 16 entries */
	0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
	0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
};
EXPORT_SYMBOL(isa_irq_to_vector_map);

static unsigned long ia64_vector_mask[BITS_TO_LONGS(IA64_MAX_DEVICE_VECTORS)];

int
assign_irq_vector (int irq)
{
	int pos, vector;
 again:
	pos = find_first_zero_bit(ia64_vector_mask, IA64_NUM_DEVICE_VECTORS);
	vector = IA64_FIRST_DEVICE_VECTOR + pos;
	if (vector > IA64_LAST_DEVICE_VECTOR)
		return -ENOSPC;
	if (test_and_set_bit(pos, ia64_vector_mask))
		goto again;
	return vector;
}

void
free_irq_vector (int vector)
{
	int pos;

	if (vector < IA64_FIRST_DEVICE_VECTOR || vector > IA64_LAST_DEVICE_VECTOR)
		return;

	pos = vector - IA64_FIRST_DEVICE_VECTOR;
	if (!test_and_clear_bit(pos, ia64_vector_mask))
		printk(KERN_WARNING "%s: double free!\n", __FUNCTION__);
}

int
reserve_irq_vector (int vector)
{
	int pos;

	if (vector < IA64_FIRST_DEVICE_VECTOR ||
	    vector > IA64_LAST_DEVICE_VECTOR)
		return -EINVAL;

	pos = vector - IA64_FIRST_DEVICE_VECTOR;
	return test_and_set_bit(pos, ia64_vector_mask);
}

/*
 * Dynamic irq allocate and deallocation for MSI
 */
int create_irq(void)
{
	int vector = assign_irq_vector(AUTO_ASSIGN);

	if (vector >= 0)
		dynamic_irq_init(vector);

	return vector;
}

void destroy_irq(unsigned int irq)
{
	dynamic_irq_cleanup(irq);
	free_irq_vector(irq);
}

#ifdef CONFIG_SMP
#	define IS_RESCHEDULE(vec)	(vec == IA64_IPI_RESCHEDULE)
#else
#	define IS_RESCHEDULE(vec)	(0)
#endif
/*
 * That's where the IVT branches when we get an external
 * interrupt. This branches to the correct hardware IRQ handler via
 * function ptr.
 */
void
ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);
	unsigned long saved_tpr;

#if IRQ_DEBUG
	{
		unsigned long bsp, sp;

		/*
		 * Note: if the interrupt happened while executing in
		 * the context switch routine (ia64_switch_to), we may
		 * get a spurious stack overflow here.  This is
		 * because the register and the memory stack are not
		 * switched atomically.
		 */
		bsp = ia64_getreg(_IA64_REG_AR_BSP);
		sp = ia64_getreg(_IA64_REG_SP);

		if ((sp - bsp) < 1024) {
			static unsigned char count;
			static long last_time;

			if (jiffies - last_time > 5*HZ)
				count = 0;
			if (++count < 5) {
				last_time = jiffies;
				printk("ia64_handle_irq: DANGER: less than "
				       "1KB of free stack space!!\n"
				       "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
			}
		}
	}
#endif /* IRQ_DEBUG */

	/*
	 * Always set TPR to limit maximum interrupt nesting depth to
	 * 16 (without this, it would be ~240, which could easily lead
	 * to kernel stack overflows).
	 */
	irq_enter();
	saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
	ia64_srlz_d();
	while (vector != IA64_SPURIOUS_INT_VECTOR) {
		if (unlikely(IS_RESCHEDULE(vector)))
			 kstat_this_cpu.irqs[vector]++;
		else {
			ia64_setreg(_IA64_REG_CR_TPR, vector);
			ia64_srlz_d();

			generic_handle_irq(local_vector_to_irq(vector));

			/*
			 * Disable interrupts and send EOI:
			 */
			local_irq_disable();
			ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
		}
		ia64_eoi();
		vector = ia64_get_ivr();
	}
	/*
	 * This must be done *after* the ia64_eoi().  For example, the keyboard softirq
	 * handler needs to be able to wait for further keyboard interrupts, which can't
	 * come through until ia64_eoi() has been done.
	 */
	irq_exit();
	set_irq_regs(old_regs);
}

#ifdef CONFIG_HOTPLUG_CPU
/*
 * This function emulates a interrupt processing when a cpu is about to be
 * brought down.
 */
void ia64_process_pending_intr(void)
{
	ia64_vector vector;
	unsigned long saved_tpr;
	extern unsigned int vectors_in_migration[NR_IRQS];

	vector = ia64_get_ivr();

	 irq_enter();
	 saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
	 ia64_srlz_d();

	 /*
	  * Perform normal interrupt style processing
	  */
	while (vector != IA64_SPURIOUS_INT_VECTOR) {
		if (unlikely(IS_RESCHEDULE(vector)))
			 kstat_this_cpu.irqs[vector]++;
		else {
			struct pt_regs *old_regs = set_irq_regs(NULL);

			ia64_setreg(_IA64_REG_CR_TPR, vector);
			ia64_srlz_d();

			/*
			 * Now try calling normal ia64_handle_irq as it would have got called
			 * from a real intr handler. Try passing null for pt_regs, hopefully
			 * it will work. I hope it works!.
			 * Probably could shared code.
			 */
			vectors_in_migration[local_vector_to_irq(vector)]=0;
			generic_handle_irq(local_vector_to_irq(vector));
			set_irq_regs(old_regs);

			/*
			 * Disable interrupts and send EOI
			 */
			local_irq_disable();
			ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
		}
		ia64_eoi();
		vector = ia64_get_ivr();
	}
	irq_exit();
}
#endif


#ifdef CONFIG_SMP
extern irqreturn_t handle_IPI (int irq, void *dev_id);

static irqreturn_t dummy_handler (int irq, void *dev_id)
{
	BUG();
}

static struct irqaction ipi_irqaction = {
	.handler =	handle_IPI,
	.flags =	IRQF_DISABLED,
	.name =		"IPI"
};

static struct irqaction resched_irqaction = {
	.handler =	dummy_handler,
	.flags =	IRQF_DISABLED,
	.name =		"resched"
};
#endif

void
register_percpu_irq (ia64_vector vec, struct irqaction *action)
{
	irq_desc_t *desc;
	unsigned int irq;

	for (irq = 0; irq < NR_IRQS; ++irq)
		if (irq_to_vector(irq) == vec) {
			desc = irq_desc + irq;
			desc->status |= IRQ_PER_CPU;
			desc->chip = &irq_type_ia64_lsapic;
			if (action)
				setup_irq(irq, action);
		}
}

void __init
init_IRQ (void)
{
	register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
#ifdef CONFIG_SMP
	register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
	register_percpu_irq(IA64_IPI_RESCHEDULE, &resched_irqaction);
#endif
#ifdef CONFIG_PERFMON
	pfm_init_percpu();
#endif
	platform_irq_init();
}

void
ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
{
	void __iomem *ipi_addr;
	unsigned long ipi_data;
	unsigned long phys_cpu_id;

#ifdef CONFIG_SMP
	phys_cpu_id = cpu_physical_id(cpu);
#else
	phys_cpu_id = (ia64_getreg(_IA64_REG_CR_LID) >> 16) & 0xffff;
#endif

	/*
	 * cpu number is in 8bit ID and 8bit EID
	 */

	ipi_data = (delivery_mode << 8) | (vector & 0xff);
	ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));

	writeq(ipi_data, ipi_addr);
}
OpenPOWER on IntegriCloud