1/*
2 *	linux/arch/ia64/kernel/irq.c
3 *
4 *	Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
5 *
6 * This file contains the code used by various IRQ handling routines:
7 * asking for different IRQs should be done through these routines
8 * instead of just grabbing them. Thus setups with different IRQ numbers
9 * shouldn't result in any weird surprises, and installing new handlers
10 * should be easier.
11 *
12 * Copyright (C) Ashok Raj<ashok.raj@intel.com>, Intel Corporation 2004
13 *
14 * 4/14/2004: Added code to handle cpu migration and do safe irq
15 *			migration without losing interrupts for iosapic
16 *			architecture.
17 */
18
19#include <asm/delay.h>
20#include <asm/uaccess.h>
21#include <linux/module.h>
22#include <linux/seq_file.h>
23#include <linux/interrupt.h>
24#include <linux/kernel_stat.h>
25
26/*
27 * 'what should we do if we get a hw irq event on an illegal vector'.
28 * each architecture has to answer this themselves.
29 */
30void ack_bad_irq(unsigned int irq)
31{
32	printk(KERN_ERR "Unexpected irq vector 0x%x on CPU %u!\n", irq, smp_processor_id());
33}
34
35#ifdef CONFIG_IA64_GENERIC
36unsigned int __ia64_local_vector_to_irq (ia64_vector vec)
37{
38	return (unsigned int) vec;
39}
40#endif
41
42/*
43 * Interrupt statistics:
44 */
45
46atomic_t irq_err_count;
47
48/*
49 * /proc/interrupts printing:
50 */
51
52int show_interrupts(struct seq_file *p, void *v)
53{
54	int i = *(loff_t *) v, j;
55	struct irqaction * action;
56	unsigned long flags;
57
58	if (i == 0) {
59		seq_printf(p, "           ");
60		for_each_online_cpu(j) {
61			seq_printf(p, "CPU%d       ",j);
62		}
63		seq_putc(p, '\n');
64	}
65
66	if (i < NR_IRQS) {
67		spin_lock_irqsave(&irq_desc[i].lock, flags);
68		action = irq_desc[i].action;
69		if (!action)
70			goto skip;
71		seq_printf(p, "%3d: ",i);
72#ifndef CONFIG_SMP
73		seq_printf(p, "%10u ", kstat_irqs(i));
74#else
75		for_each_online_cpu(j) {
76			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
77		}
78#endif
79		seq_printf(p, " %14s", irq_desc[i].chip->name);
80		seq_printf(p, "  %s", action->name);
81
82		for (action=action->next; action; action = action->next)
83			seq_printf(p, ", %s", action->name);
84
85		seq_putc(p, '\n');
86skip:
87		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
88	} else if (i == NR_IRQS)
89		seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
90	return 0;
91}
92
93#ifdef CONFIG_SMP
94static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
95
96void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
97{
98	cpumask_t mask = CPU_MASK_NONE;
99
100	cpu_set(cpu_logical_id(hwid), mask);
101
102	if (irq < NR_IRQS) {
103		irq_desc[irq].affinity = mask;
104		irq_redir[irq] = (char) (redir & 0xff);
105	}
106}
107
108bool is_affinity_mask_valid(cpumask_t cpumask)
109{
110	if (ia64_platform_is("sn2")) {
111		/* Only allow one CPU to be specified in the smp_affinity mask */
112		if (cpus_weight(cpumask) != 1)
113			return false;
114	}
115	return true;
116}
117
118#endif /* CONFIG_SMP */
119
120#ifdef CONFIG_HOTPLUG_CPU
121unsigned int vectors_in_migration[NR_IRQS];
122
123/*
124 * Since cpu_online_map is already updated, we just need to check for
125 * affinity that has zeros
126 */
127static void migrate_irqs(void)
128{
129	cpumask_t	mask;
130	irq_desc_t *desc;
131	int 		irq, new_cpu;
132
133	for (irq=0; irq < NR_IRQS; irq++) {
134		desc = irq_desc + irq;
135
136		if (desc->status == IRQ_DISABLED)
137			continue;
138
139		/*
140		 * No handling for now.
141		 * TBD: Implement a disable function so we can now
142		 * tell CPU not to respond to these local intr sources.
143		 * such as ITV,CPEI,MCA etc.
144		 */
145		if (desc->status == IRQ_PER_CPU)
146			continue;
147
148		cpus_and(mask, irq_desc[irq].affinity, cpu_online_map);
149		if (any_online_cpu(mask) == NR_CPUS) {
150			/*
151			 * Save it for phase 2 processing
152			 */
153			vectors_in_migration[irq] = irq;
154
155			new_cpu = any_online_cpu(cpu_online_map);
156			mask = cpumask_of_cpu(new_cpu);
157
158			/*
159			 * Al three are essential, currently WARN_ON.. maybe panic?
160			 */
161			if (desc->chip && desc->chip->disable &&
162				desc->chip->enable && desc->chip->set_affinity) {
163				desc->chip->disable(irq);
164				desc->chip->set_affinity(irq, mask);
165				desc->chip->enable(irq);
166			} else {
167				WARN_ON((!(desc->chip) || !(desc->chip->disable) ||
168						!(desc->chip->enable) ||
169						!(desc->chip->set_affinity)));
170			}
171		}
172	}
173}
174
175void fixup_irqs(void)
176{
177	unsigned int irq;
178	extern void ia64_process_pending_intr(void);
179	extern void ia64_disable_timer(void);
180	extern volatile int time_keeper_id;
181
182	ia64_disable_timer();
183
184	/*
185	 * Find a new timesync master
186	 */
187	if (smp_processor_id() == time_keeper_id) {
188		time_keeper_id = first_cpu(cpu_online_map);
189		printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id);
190	}
191
192	/*
193	 * Phase 1: Locate IRQs bound to this cpu and
194	 * relocate them for cpu removal.
195	 */
196	migrate_irqs();
197
198	/*
199	 * Phase 2: Perform interrupt processing for all entries reported in
200	 * local APIC.
201	 */
202	ia64_process_pending_intr();
203
204	/*
205	 * Phase 3: Now handle any interrupts not captured in local APIC.
206	 * This is to account for cases that device interrupted during the time the
207	 * rte was being disabled and re-programmed.
208	 */
209	for (irq=0; irq < NR_IRQS; irq++) {
210		if (vectors_in_migration[irq]) {
211			struct pt_regs *old_regs = set_irq_regs(NULL);
212
213			vectors_in_migration[irq]=0;
214			generic_handle_irq(irq);
215			set_irq_regs(old_regs);
216		}
217	}
218
219	/*
220	 * Now let processor die. We do irq disable and max_xtp() to
221	 * ensure there is no more interrupts routed to this processor.
222	 * But the local timer interrupt can have 1 pending which we
223	 * take care in timer_interrupt().
224	 */
225	max_xtp();
226	local_irq_disable();
227}
228#endif
229