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 */
ack_bad_irq(unsigned int irq)30 void 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
__ia64_irq_to_vector(int irq)36 ia64_vector __ia64_irq_to_vector(int irq)
37 {
38 return irq_cfg[irq].vector;
39 }
40
__ia64_local_vector_to_irq(ia64_vector vec)41 unsigned int __ia64_local_vector_to_irq (ia64_vector vec)
42 {
43 return __get_cpu_var(vector_irq)[vec];
44 }
45 #endif
46
47 /*
48 * Interrupt statistics:
49 */
50
51 atomic_t irq_err_count;
52
53 /*
54 * /proc/interrupts printing:
55 */
arch_show_interrupts(struct seq_file * p,int prec)56 int arch_show_interrupts(struct seq_file *p, int prec)
57 {
58 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
59 return 0;
60 }
61
62 #ifdef CONFIG_SMP
63 static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
64
set_irq_affinity_info(unsigned int irq,int hwid,int redir)65 void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
66 {
67 if (irq < NR_IRQS) {
68 cpumask_copy(irq_get_irq_data(irq)->affinity,
69 cpumask_of(cpu_logical_id(hwid)));
70 irq_redir[irq] = (char) (redir & 0xff);
71 }
72 }
73
is_affinity_mask_valid(const struct cpumask * cpumask)74 bool is_affinity_mask_valid(const struct cpumask *cpumask)
75 {
76 if (ia64_platform_is("sn2")) {
77 /* Only allow one CPU to be specified in the smp_affinity mask */
78 if (cpumask_weight(cpumask) != 1)
79 return false;
80 }
81 return true;
82 }
83
84 #endif /* CONFIG_SMP */
85
86 #ifdef CONFIG_HOTPLUG_CPU
87 unsigned int vectors_in_migration[NR_IRQS];
88
89 /*
90 * Since cpu_online_mask is already updated, we just need to check for
91 * affinity that has zeros
92 */
migrate_irqs(void)93 static void migrate_irqs(void)
94 {
95 int irq, new_cpu;
96
97 for (irq=0; irq < NR_IRQS; irq++) {
98 struct irq_desc *desc = irq_to_desc(irq);
99 struct irq_data *data = irq_desc_get_irq_data(desc);
100 struct irq_chip *chip = irq_data_get_irq_chip(data);
101
102 if (irqd_irq_disabled(data))
103 continue;
104
105 /*
106 * No handling for now.
107 * TBD: Implement a disable function so we can now
108 * tell CPU not to respond to these local intr sources.
109 * such as ITV,CPEI,MCA etc.
110 */
111 if (irqd_is_per_cpu(data))
112 continue;
113
114 if (cpumask_any_and(data->affinity, cpu_online_mask)
115 >= nr_cpu_ids) {
116 /*
117 * Save it for phase 2 processing
118 */
119 vectors_in_migration[irq] = irq;
120
121 new_cpu = cpumask_any(cpu_online_mask);
122
123 /*
124 * Al three are essential, currently WARN_ON.. maybe panic?
125 */
126 if (chip && chip->irq_disable &&
127 chip->irq_enable && chip->irq_set_affinity) {
128 chip->irq_disable(data);
129 chip->irq_set_affinity(data,
130 cpumask_of(new_cpu), false);
131 chip->irq_enable(data);
132 } else {
133 WARN_ON((!chip || !chip->irq_disable ||
134 !chip->irq_enable ||
135 !chip->irq_set_affinity));
136 }
137 }
138 }
139 }
140
fixup_irqs(void)141 void fixup_irqs(void)
142 {
143 unsigned int irq;
144 extern void ia64_process_pending_intr(void);
145 extern volatile int time_keeper_id;
146
147 /* Mask ITV to disable timer */
148 ia64_set_itv(1 << 16);
149
150 /*
151 * Find a new timesync master
152 */
153 if (smp_processor_id() == time_keeper_id) {
154 time_keeper_id = cpumask_first(cpu_online_mask);
155 printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id);
156 }
157
158 /*
159 * Phase 1: Locate IRQs bound to this cpu and
160 * relocate them for cpu removal.
161 */
162 migrate_irqs();
163
164 /*
165 * Phase 2: Perform interrupt processing for all entries reported in
166 * local APIC.
167 */
168 ia64_process_pending_intr();
169
170 /*
171 * Phase 3: Now handle any interrupts not captured in local APIC.
172 * This is to account for cases that device interrupted during the time the
173 * rte was being disabled and re-programmed.
174 */
175 for (irq=0; irq < NR_IRQS; irq++) {
176 if (vectors_in_migration[irq]) {
177 struct pt_regs *old_regs = set_irq_regs(NULL);
178
179 vectors_in_migration[irq]=0;
180 generic_handle_irq(irq);
181 set_irq_regs(old_regs);
182 }
183 }
184
185 /*
186 * Now let processor die. We do irq disable and max_xtp() to
187 * ensure there is no more interrupts routed to this processor.
188 * But the local timer interrupt can have 1 pending which we
189 * take care in timer_interrupt().
190 */
191 max_xtp();
192 local_irq_disable();
193 }
194 #endif
195