[linux-2.6-block.git] / arch / parisc / kernel / irq.c

/* 
 * Code to handle x86 style IRQs plus some generic interrupt stuff.
 *
 * Copyright (C) 1992 Linus Torvalds
 * Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle
 * Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
 * Copyright (C) 1999-2000 Grant Grundler
 * Copyright (c) 2005 Matthew Wilcox
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <linux/bitops.h>
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/types.h>

#undef PARISC_IRQ_CR16_COUNTS

extern irqreturn_t timer_interrupt(int, void *, struct pt_regs *);
extern irqreturn_t ipi_interrupt(int, void *, struct pt_regs *);

#define EIEM_MASK(irq)       (1UL<<(CPU_IRQ_MAX - irq))

/* Bits in EIEM correlate with cpu_irq_action[].
** Numbered *Big Endian*! (ie bit 0 is MSB)
*/
static volatile unsigned long cpu_eiem = 0;

static void cpu_set_eiem(void *info)
{
	set_eiem((unsigned long) info);
}

static inline void cpu_disable_irq(unsigned int irq)
{
	unsigned long eirr_bit = EIEM_MASK(irq);

	cpu_eiem &= ~eirr_bit;
        on_each_cpu(cpu_set_eiem, (void *) cpu_eiem, 1, 1);
}

static void cpu_enable_irq(unsigned int irq)
{
	unsigned long eirr_bit = EIEM_MASK(irq);

	mtctl(eirr_bit, 23);	/* clear EIRR bit before unmasking */
	cpu_eiem |= eirr_bit;
        on_each_cpu(cpu_set_eiem, (void *) cpu_eiem, 1, 1);
}

static unsigned int cpu_startup_irq(unsigned int irq)
{
	cpu_enable_irq(irq);
	return 0;
}

void no_ack_irq(unsigned int irq) { }
void no_end_irq(unsigned int irq) { }

static struct hw_interrupt_type cpu_interrupt_type = {
	.typename	= "CPU",
	.startup	= cpu_startup_irq,
	.shutdown	= cpu_disable_irq,
	.enable		= cpu_enable_irq,
	.disable	= cpu_disable_irq,
	.ack		= no_ack_irq,
	.end		= no_end_irq,
//	.set_affinity	= cpu_set_affinity_irq,
};

int show_interrupts(struct seq_file *p, void *v)
{
	int i = *(loff_t *) v, j;
	unsigned long flags;

	if (i == 0) {
		seq_puts(p, "    ");
		for_each_online_cpu(j)
			seq_printf(p, "       CPU%d", j);

#ifdef PARISC_IRQ_CR16_COUNTS
		seq_printf(p, " [min/avg/max] (CPU cycle counts)");
#endif
		seq_putc(p, '\n');
	}

	if (i < NR_IRQS) {
		struct irqaction *action;

		spin_lock_irqsave(&irq_desc[i].lock, flags);
		action = irq_desc[i].action;
		if (!action)
			goto skip;
		seq_printf(p, "%3d: ", i);
#ifdef CONFIG_SMP
		for_each_online_cpu(j)
			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#else
		seq_printf(p, "%10u ", kstat_irqs(i));
#endif

		seq_printf(p, " %14s", irq_desc[i].handler->typename);
#ifndef PARISC_IRQ_CR16_COUNTS
		seq_printf(p, "  %s", action->name);

		while ((action = action->next))
			seq_printf(p, ", %s", action->name);
#else
		for ( ;action; action = action->next) {
			unsigned int k, avg, min, max;

			min = max = action->cr16_hist[0];

			for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) {
				int hist = action->cr16_hist[k];

				if (hist) {
					avg += hist;
				} else
					break;

				if (hist > max) max = hist;
				if (hist < min) min = hist;
			}

			avg /= k;
			seq_printf(p, " %s[%d/%d/%d]", action->name,
					min,avg,max);
		}
#endif

		seq_putc(p, '\n');
 skip:
		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
	}

	return 0;
}


/*
** The following form a "set": Virtual IRQ, Transaction Address, Trans Data.
** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit.
**
** To use txn_XXX() interfaces, get a Virtual IRQ first.
** Then use that to get the Transaction address and data.
*/

int cpu_claim_irq(unsigned int irq, struct hw_interrupt_type *type, void *data)
{
	if (irq_desc[irq].action)
		return -EBUSY;
	if (irq_desc[irq].handler != &cpu_interrupt_type)
		return -EBUSY;

	if (type) {
		irq_desc[irq].handler = type;
		irq_desc[irq].handler_data = data;
		cpu_interrupt_type.enable(irq);
	}
	return 0;
}

int txn_claim_irq(int irq)
{
	return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq;
}

/*
 * The bits_wide parameter accommodates the limitations of the HW/SW which
 * use these bits:
 * Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register)
 * V-class (EPIC):          6 bits
 * N/L/A-class (iosapic):   8 bits
 * PCI 2.2 MSI:            16 bits
 * Some PCI devices:       32 bits (Symbios SCSI/ATM/HyperFabric)
 *
 * On the service provider side:
 * o PA 1.1 (and PA2.0 narrow mode)     5-bits (width of EIR register)
 * o PA 2.0 wide mode                   6-bits (per processor)
 * o IA64                               8-bits (0-256 total)
 *
 * So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported
 * by the processor...and the N/L-class I/O subsystem supports more bits than
 * PA2.0 has. The first case is the problem.
 */
int txn_alloc_irq(unsigned int bits_wide)
{
	int irq;

	/* never return irq 0 cause that's the interval timer */
	for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) {
		if (cpu_claim_irq(irq, NULL, NULL) < 0)
			continue;
		if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide))
			continue;
		return irq;
	}

	/* unlikely, but be prepared */
	return -1;
}

unsigned long txn_alloc_addr(unsigned int virt_irq)
{
	static int next_cpu = -1;

	next_cpu++; /* assign to "next" CPU we want this bugger on */

	/* validate entry */
	while ((next_cpu < NR_CPUS) && (!cpu_data[next_cpu].txn_addr || 
		!cpu_online(next_cpu)))
		next_cpu++;

	if (next_cpu >= NR_CPUS) 
		next_cpu = 0;	/* nothing else, assign monarch */

	return cpu_data[next_cpu].txn_addr;
}


unsigned int txn_alloc_data(unsigned int virt_irq)
{
	return virt_irq - CPU_IRQ_BASE;
}

/* ONLY called from entry.S:intr_extint() */
void do_cpu_irq_mask(struct pt_regs *regs)
{
	unsigned long eirr_val;

	irq_enter();

	/*
	 * Don't allow TIMER or IPI nested interrupts.
	 * Allowing any single interrupt to nest can lead to that CPU
	 * handling interrupts with all enabled interrupts unmasked.
	 */
	set_eiem(0UL);

	/* 1) only process IRQs that are enabled/unmasked (cpu_eiem)
	 * 2) We loop here on EIRR contents in order to avoid
	 *    nested interrupts or having to take another interrupt
	 *    when we could have just handled it right away.
	 */
	for (;;) {
		unsigned long bit = (1UL << (BITS_PER_LONG - 1));
		unsigned int irq;
		eirr_val = mfctl(23) & cpu_eiem;
		if (!eirr_val)
			break;

		mtctl(eirr_val, 23); /* reset bits we are going to process */

		/* Work our way from MSb to LSb...same order we alloc EIRs */
		for (irq = TIMER_IRQ; eirr_val && bit; bit>>=1, irq++) {
			if (!(bit & eirr_val))
				continue;

			/* clear bit in mask - can exit loop sooner */
			eirr_val &= ~bit;

			__do_IRQ(irq, regs);
		}
	}

	set_eiem(cpu_eiem);	/* restore original mask */
	irq_exit();
}


static struct irqaction timer_action = {
	.handler = timer_interrupt,
	.name = "timer",
	.flags = SA_INTERRUPT,
};

#ifdef CONFIG_SMP
static struct irqaction ipi_action = {
	.handler = ipi_interrupt,
	.name = "IPI",
	.flags = SA_INTERRUPT,
};
#endif

static void claim_cpu_irqs(void)
{
	int i;
	for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
		irq_desc[i].handler = &cpu_interrupt_type;
	}

	irq_desc[TIMER_IRQ].action = &timer_action;
	irq_desc[TIMER_IRQ].status |= IRQ_PER_CPU;
#ifdef CONFIG_SMP
	irq_desc[IPI_IRQ].action = &ipi_action;
	irq_desc[IPI_IRQ].status = IRQ_PER_CPU;
#endif
}

void __init init_IRQ(void)
{
	local_irq_disable();	/* PARANOID - should already be disabled */
	mtctl(~0UL, 23);	/* EIRR : clear all pending external intr */
	claim_cpu_irqs();
#ifdef CONFIG_SMP
	if (!cpu_eiem)
		cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ);
#else
	cpu_eiem = EIEM_MASK(TIMER_IRQ);
#endif
        set_eiem(cpu_eiem);	/* EIEM : enable all external intr */

}

void hw_resend_irq(struct hw_interrupt_type *type, unsigned int irq)
{
	/* XXX: Needs to be written.  We managed without it so far, but
	 * we really ought to write it.
	 */
}

void ack_bad_irq(unsigned int irq)
{
	printk("unexpected IRQ %d\n", irq);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Code to handle x86 style IRQs plus some generic interrupt stuff.
	3	*
	4	* Copyright (C) 1992 Linus Torvalds
	5	* Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle
	6	* Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
	7	* Copyright (C) 1999-2000 Grant Grundler
	8	* Copyright (c) 2005 Matthew Wilcox
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; either version 2, or (at your option)
	13	* any later version.
	14	*
	15	* This program is distributed in the hope that it will be useful,
	16	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	* GNU General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with this program; if not, write to the Free Software
	22	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	23	*/
	24	#include <linux/bitops.h>
	25	#include <linux/config.h>
	26	#include <linux/errno.h>
	27	#include <linux/init.h>
	28	#include <linux/interrupt.h>
	29	#include <linux/kernel_stat.h>
	30	#include <linux/seq_file.h>
	31	#include <linux/spinlock.h>
	32	#include <linux/types.h>
	33
	34	#undef PARISC_IRQ_CR16_COUNTS
	35
	36	extern irqreturn_t timer_interrupt(int, void , struct pt_regs );
	37	extern irqreturn_t ipi_interrupt(int, void , struct pt_regs );
	38
	39	#define EIEM_MASK(irq) (1UL<<(CPU_IRQ_MAX - irq))
	40
	41	/* Bits in EIEM correlate with cpu_irq_action[].
	42	** Numbered Big Endian! (ie bit 0 is MSB)
	43	*/
	44	static volatile unsigned long cpu_eiem = 0;
	45
	46	static void cpu_set_eiem(void *info)
	47	{
	48	set_eiem((unsigned long) info);
	49	}
	50
	51	static inline void cpu_disable_irq(unsigned int irq)
	52	{
	53	unsigned long eirr_bit = EIEM_MASK(irq);
	54
	55	cpu_eiem &= ~eirr_bit;
	56	on_each_cpu(cpu_set_eiem, (void *) cpu_eiem, 1, 1);
	57	}
	58
	59	static void cpu_enable_irq(unsigned int irq)
	60	{
	61	unsigned long eirr_bit = EIEM_MASK(irq);
	62
	63	mtctl(eirr_bit, 23); /* clear EIRR bit before unmasking */
	64	cpu_eiem \|= eirr_bit;
65	on_each_cpu(cpu_set_eiem, (void *) cpu_eiem, 1, 1);
66	}
67
68	static unsigned int cpu_startup_irq(unsigned int irq)
69	{
70	cpu_enable_irq(irq);
71	return 0;
72	}
73
74	void no_ack_irq(unsigned int irq) { }
75	void no_end_irq(unsigned int irq) { }
76
77	static struct hw_interrupt_type cpu_interrupt_type = {
78	.typename = "CPU",
79	.startup = cpu_startup_irq,
80	.shutdown = cpu_disable_irq,
81	.enable = cpu_enable_irq,
82	.disable = cpu_disable_irq,
83	.ack = no_ack_irq,
84	.end = no_end_irq,
85	// .set_affinity = cpu_set_affinity_irq,
86	};
87
88	int show_interrupts(struct seq_file p, void v)
89	{
90	int i = (loff_t ) v, j;
91	unsigned long flags;
92
93	if (i == 0) {
94	seq_puts(p, " ");
95	for_each_online_cpu(j)
96	seq_printf(p, " CPU%d", j);
97
98	#ifdef PARISC_IRQ_CR16_COUNTS
99	seq_printf(p, " [min/avg/max] (CPU cycle counts)");
100	#endif
101	seq_putc(p, '\n');
102	}
103
104	if (i < NR_IRQS) {
105	struct irqaction *action;
106
107	spin_lock_irqsave(&irq_desc[i].lock, flags);
108	action = irq_desc[i].action;
109	if (!action)
110	goto skip;
111	seq_printf(p, "%3d: ", i);
112	#ifdef CONFIG_SMP
113	for_each_online_cpu(j)
114	seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
115	#else
116	seq_printf(p, "%10u ", kstat_irqs(i));
117	#endif
118
119	seq_printf(p, " %14s", irq_desc[i].handler->typename);
120	#ifndef PARISC_IRQ_CR16_COUNTS
121	seq_printf(p, " %s", action->name);
122
123	while ((action = action->next))
124	seq_printf(p, ", %s", action->name);
125	#else
126	for ( ;action; action = action->next) {
127	unsigned int k, avg, min, max;
128
129	min = max = action->cr16_hist[0];
130
131	for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) {
132	int hist = action->cr16_hist[k];
133
134	if (hist) {
135	avg += hist;
136	} else
137	break;
138
139	if (hist > max) max = hist;
140	if (hist < min) min = hist;
141	}
142
143	avg /= k;
144	seq_printf(p, " %s[%d/%d/%d]", action->name,
145	min,avg,max);
146	}
147	#endif
148
149	seq_putc(p, '\n');
150	skip:
151	spin_unlock_irqrestore(&irq_desc[i].lock, flags);
152	}
153
154	return 0;
155	}
156
157
158
159	/*
160	** The following form a "set": Virtual IRQ, Transaction Address, Trans Data.
161	** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit.
162	**
163	** To use txn_XXX() interfaces, get a Virtual IRQ first.
164	** Then use that to get the Transaction address and data.
165	*/
166
167	int cpu_claim_irq(unsigned int irq, struct hw_interrupt_type type, void data)
168	{
169	if (irq_desc[irq].action)
170	return -EBUSY;
171	if (irq_desc[irq].handler != &cpu_interrupt_type)
172	return -EBUSY;
173
174	if (type) {
175	irq_desc[irq].handler = type;
176	irq_desc[irq].handler_data = data;
177	cpu_interrupt_type.enable(irq);
178	}
179	return 0;
180	}
181
182	int txn_claim_irq(int irq)
183	{
184	return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq;
185	}
186
187	/*
188	* The bits_wide parameter accommodates the limitations of the HW/SW which
189	* use these bits:
190	* Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register)
191	* V-class (EPIC): 6 bits
192	* N/L/A-class (iosapic): 8 bits
193	* PCI 2.2 MSI: 16 bits
194	* Some PCI devices: 32 bits (Symbios SCSI/ATM/HyperFabric)
195	*
196	* On the service provider side:
197	* o PA 1.1 (and PA2.0 narrow mode) 5-bits (width of EIR register)
198	* o PA 2.0 wide mode 6-bits (per processor)
199	* o IA64 8-bits (0-256 total)
200	*
201	* So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported
202	* by the processor...and the N/L-class I/O subsystem supports more bits than
203	* PA2.0 has. The first case is the problem.
204	*/
205	int txn_alloc_irq(unsigned int bits_wide)
206	{
207	int irq;
208
209	/* never return irq 0 cause that's the interval timer */
210	for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) {
211	if (cpu_claim_irq(irq, NULL, NULL) < 0)
212	continue;
213	if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide))
214	continue;
215	return irq;
216	}
217
218	/* unlikely, but be prepared */
219	return -1;
220	}
221
222	unsigned long txn_alloc_addr(unsigned int virt_irq)
223	{
224	static int next_cpu = -1;
225
226	next_cpu++; /* assign to "next" CPU we want this bugger on */
227
228	/* validate entry */
229	while ((next_cpu < NR_CPUS) && (!cpu_data[next_cpu].txn_addr \|\|
230	!cpu_online(next_cpu)))
231	next_cpu++;
232
233	if (next_cpu >= NR_CPUS)
234	next_cpu = 0; /* nothing else, assign monarch */
235
236	return cpu_data[next_cpu].txn_addr;
237	}
238
239
240	unsigned int txn_alloc_data(unsigned int virt_irq)
241	{
242	return virt_irq - CPU_IRQ_BASE;
243	}
244
245	/* ONLY called from entry.S:intr_extint() */
246	void do_cpu_irq_mask(struct pt_regs *regs)
247	{
248	unsigned long eirr_val;
249
250	irq_enter();
251
252	/*
3f902886 GG	253	* Don't allow TIMER or IPI nested interrupts.
	254	* Allowing any single interrupt to nest can lead to that CPU
	255	* handling interrupts with all enabled interrupts unmasked.
1da177e4	256	*/
3f902886	257	set_eiem(0UL);
1da177e4 LT	258
	259	/* 1) only process IRQs that are enabled/unmasked (cpu_eiem)
	260	* 2) We loop here on EIRR contents in order to avoid
	261	* nested interrupts or having to take another interrupt
	262	* when we could have just handled it right away.
	263	*/
	264	for (;;) {
	265	unsigned long bit = (1UL << (BITS_PER_LONG - 1));
	266	unsigned int irq;
	267	eirr_val = mfctl(23) & cpu_eiem;
	268	if (!eirr_val)
	269	break;
	270
1da177e4 LT	271	mtctl(eirr_val, 23); /* reset bits we are going to process */
	272
	273	/* Work our way from MSb to LSb...same order we alloc EIRs */
	274	for (irq = TIMER_IRQ; eirr_val && bit; bit>>=1, irq++) {
	275	if (!(bit & eirr_val))
	276	continue;
	277
	278	/* clear bit in mask - can exit loop sooner */
	279	eirr_val &= ~bit;
	280
	281	__do_IRQ(irq, regs);
	282	}
	283	}
3f902886 GG	284
3f902886 GG	285	set_eiem(cpu_eiem); /* restore original mask */
1da177e4 LT	286	irq_exit();
	287	}
	288
	289
	290	static struct irqaction timer_action = {
	291	.handler = timer_interrupt,
	292	.name = "timer",
9a8b4584	293	.flags = SA_INTERRUPT,
1da177e4 LT	294	};
	295
	296	#ifdef CONFIG_SMP
	297	static struct irqaction ipi_action = {
	298	.handler = ipi_interrupt,
	299	.name = "IPI",
9a8b4584	300	.flags = SA_INTERRUPT,
1da177e4 LT	301	};
	302	#endif
	303
	304	static void claim_cpu_irqs(void)
	305	{
	306	int i;
	307	for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
	308	irq_desc[i].handler = &cpu_interrupt_type;
	309	}
	310
	311	irq_desc[TIMER_IRQ].action = &timer_action;
	312	irq_desc[TIMER_IRQ].status \|= IRQ_PER_CPU;
	313	#ifdef CONFIG_SMP
	314	irq_desc[IPI_IRQ].action = &ipi_action;
	315	irq_desc[IPI_IRQ].status = IRQ_PER_CPU;
	316	#endif
	317	}
	318
	319	void __init init_IRQ(void)
	320	{
	321	local_irq_disable(); /* PARANOID - should already be disabled */
	322	mtctl(~0UL, 23); /* EIRR : clear all pending external intr */
	323	claim_cpu_irqs();
	324	#ifdef CONFIG_SMP
	325	if (!cpu_eiem)
	326	cpu_eiem = EIEM_MASK(IPI_IRQ) \| EIEM_MASK(TIMER_IRQ);
	327	#else
	328	cpu_eiem = EIEM_MASK(TIMER_IRQ);
	329	#endif
	330	set_eiem(cpu_eiem); /* EIEM : enable all external intr */
	331
	332	}
	333
	334	void hw_resend_irq(struct hw_interrupt_type *type, unsigned int irq)
	335	{
	336	/* XXX: Needs to be written. We managed without it so far, but
	337	* we really ought to write it.
	338	*/
	339	}
	340
	341	void ack_bad_irq(unsigned int irq)
	342	{
	343	printk("unexpected IRQ %d\n", irq);
	344	}