]> nv-tegra.nvidia Code Review - linux-3.10.git/blob - arch/ia64/kernel/irq.c
[PATCH] kexec: Avoid migration of already disabled irqs (ia64)
[linux-3.10.git] / arch / ia64 / kernel / irq.c
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 IRQ's 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 lossing 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  */
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
36 unsigned 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
46 atomic_t irq_err_count;
47
48 /*
49  * /proc/interrupts printing:
50  */
51
52 int 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');
86 skip:
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
94 static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
95
96 void 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 #endif /* CONFIG_SMP */
108
109 #ifdef CONFIG_HOTPLUG_CPU
110 unsigned int vectors_in_migration[NR_IRQS];
111
112 /*
113  * Since cpu_online_map is already updated, we just need to check for
114  * affinity that has zeros
115  */
116 static void migrate_irqs(void)
117 {
118         cpumask_t       mask;
119         irq_desc_t *desc;
120         int             irq, new_cpu;
121
122         for (irq=0; irq < NR_IRQS; irq++) {
123                 desc = irq_desc + irq;
124
125                 if (desc->status == IRQ_DISABLED)
126                         continue;
127
128                 /*
129                  * No handling for now.
130                  * TBD: Implement a disable function so we can now
131                  * tell CPU not to respond to these local intr sources.
132                  * such as ITV,CPEI,MCA etc.
133                  */
134                 if (desc->status == IRQ_PER_CPU)
135                         continue;
136
137                 cpus_and(mask, irq_desc[irq].affinity, cpu_online_map);
138                 if (any_online_cpu(mask) == NR_CPUS) {
139                         /*
140                          * Save it for phase 2 processing
141                          */
142                         vectors_in_migration[irq] = irq;
143
144                         new_cpu = any_online_cpu(cpu_online_map);
145                         mask = cpumask_of_cpu(new_cpu);
146
147                         /*
148                          * Al three are essential, currently WARN_ON.. maybe panic?
149                          */
150                         if (desc->chip && desc->chip->disable &&
151                                 desc->chip->enable && desc->chip->set_affinity) {
152                                 desc->chip->disable(irq);
153                                 desc->chip->set_affinity(irq, mask);
154                                 desc->chip->enable(irq);
155                         } else {
156                                 WARN_ON((!(desc->chip) || !(desc->chip->disable) ||
157                                                 !(desc->chip->enable) ||
158                                                 !(desc->chip->set_affinity)));
159                         }
160                 }
161         }
162 }
163
164 void fixup_irqs(void)
165 {
166         unsigned int irq;
167         extern void ia64_process_pending_intr(void);
168         extern void ia64_disable_timer(void);
169         extern volatile int time_keeper_id;
170
171         ia64_disable_timer();
172
173         /*
174          * Find a new timesync master
175          */
176         if (smp_processor_id() == time_keeper_id) {
177                 time_keeper_id = first_cpu(cpu_online_map);
178                 printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id);
179         }
180
181         /*
182          * Phase 1: Locate irq's bound to this cpu and
183          * relocate them for cpu removal.
184          */
185         migrate_irqs();
186
187         /*
188          * Phase 2: Perform interrupt processing for all entries reported in
189          * local APIC.
190          */
191         ia64_process_pending_intr();
192
193         /*
194          * Phase 3: Now handle any interrupts not captured in local APIC.
195          * This is to account for cases that device interrupted during the time the
196          * rte was being disabled and re-programmed.
197          */
198         for (irq=0; irq < NR_IRQS; irq++) {
199                 if (vectors_in_migration[irq]) {
200                         struct pt_regs *old_regs = set_irq_regs(NULL);
201
202                         vectors_in_migration[irq]=0;
203                         generic_handle_irq(irq);
204                         set_irq_regs(old_regs);
205                 }
206         }
207
208         /*
209          * Now let processor die. We do irq disable and max_xtp() to
210          * ensure there is no more interrupts routed to this processor.
211          * But the local timer interrupt can have 1 pending which we
212          * take care in timer_interrupt().
213          */
214         max_xtp();
215         local_irq_disable();
216 }
217 #endif