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[linux-2.6] / 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 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  */
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 ia64_vector __ia64_irq_to_vector(int irq)
37 {
38         return irq_cfg[irq].vector;
39 }
40
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  */
56
57 int show_interrupts(struct seq_file *p, void *v)
58 {
59         int i = *(loff_t *) v, j;
60         struct irqaction * action;
61         unsigned long flags;
62
63         if (i == 0) {
64                 char cpuname[16];
65                 seq_printf(p, "     ");
66                 for_each_online_cpu(j) {
67                         snprintf(cpuname, 10, "CPU%d", j);
68                         seq_printf(p, "%10s ", cpuname);
69                 }
70                 seq_putc(p, '\n');
71         }
72
73         if (i < NR_IRQS) {
74                 spin_lock_irqsave(&irq_desc[i].lock, flags);
75                 action = irq_desc[i].action;
76                 if (!action)
77                         goto skip;
78                 seq_printf(p, "%3d: ",i);
79 #ifndef CONFIG_SMP
80                 seq_printf(p, "%10u ", kstat_irqs(i));
81 #else
82                 for_each_online_cpu(j) {
83                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
84                 }
85 #endif
86                 seq_printf(p, " %14s", irq_desc[i].chip->name);
87                 seq_printf(p, "  %s", action->name);
88
89                 for (action=action->next; action; action = action->next)
90                         seq_printf(p, ", %s", action->name);
91
92                 seq_putc(p, '\n');
93 skip:
94                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
95         } else if (i == NR_IRQS)
96                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
97         return 0;
98 }
99
100 #ifdef CONFIG_SMP
101 static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
102
103 void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
104 {
105         cpumask_t mask = CPU_MASK_NONE;
106
107         cpu_set(cpu_logical_id(hwid), mask);
108
109         if (irq < NR_IRQS) {
110                 irq_desc[irq].affinity = mask;
111                 irq_redir[irq] = (char) (redir & 0xff);
112         }
113 }
114
115 bool is_affinity_mask_valid(cpumask_t cpumask)
116 {
117         if (ia64_platform_is("sn2")) {
118                 /* Only allow one CPU to be specified in the smp_affinity mask */
119                 if (cpus_weight(cpumask) != 1)
120                         return false;
121         }
122         return true;
123 }
124
125 #endif /* CONFIG_SMP */
126
127 #ifdef CONFIG_HOTPLUG_CPU
128 unsigned int vectors_in_migration[NR_IRQS];
129
130 /*
131  * Since cpu_online_map is already updated, we just need to check for
132  * affinity that has zeros
133  */
134 static void migrate_irqs(void)
135 {
136         cpumask_t       mask;
137         irq_desc_t *desc;
138         int             irq, new_cpu;
139
140         for (irq=0; irq < NR_IRQS; irq++) {
141                 desc = irq_desc + irq;
142
143                 if (desc->status == IRQ_DISABLED)
144                         continue;
145
146                 /*
147                  * No handling for now.
148                  * TBD: Implement a disable function so we can now
149                  * tell CPU not to respond to these local intr sources.
150                  * such as ITV,CPEI,MCA etc.
151                  */
152                 if (desc->status == IRQ_PER_CPU)
153                         continue;
154
155                 cpus_and(mask, irq_desc[irq].affinity, cpu_online_map);
156                 if (any_online_cpu(mask) == NR_CPUS) {
157                         /*
158                          * Save it for phase 2 processing
159                          */
160                         vectors_in_migration[irq] = irq;
161
162                         new_cpu = any_online_cpu(cpu_online_map);
163                         mask = cpumask_of_cpu(new_cpu);
164
165                         /*
166                          * Al three are essential, currently WARN_ON.. maybe panic?
167                          */
168                         if (desc->chip && desc->chip->disable &&
169                                 desc->chip->enable && desc->chip->set_affinity) {
170                                 desc->chip->disable(irq);
171                                 desc->chip->set_affinity(irq, mask);
172                                 desc->chip->enable(irq);
173                         } else {
174                                 WARN_ON((!(desc->chip) || !(desc->chip->disable) ||
175                                                 !(desc->chip->enable) ||
176                                                 !(desc->chip->set_affinity)));
177                         }
178                 }
179         }
180 }
181
182 void fixup_irqs(void)
183 {
184         unsigned int irq;
185         extern void ia64_process_pending_intr(void);
186         extern void ia64_disable_timer(void);
187         extern volatile int time_keeper_id;
188
189         ia64_disable_timer();
190
191         /*
192          * Find a new timesync master
193          */
194         if (smp_processor_id() == time_keeper_id) {
195                 time_keeper_id = first_cpu(cpu_online_map);
196                 printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id);
197         }
198
199         /*
200          * Phase 1: Locate IRQs bound to this cpu and
201          * relocate them for cpu removal.
202          */
203         migrate_irqs();
204
205         /*
206          * Phase 2: Perform interrupt processing for all entries reported in
207          * local APIC.
208          */
209         ia64_process_pending_intr();
210
211         /*
212          * Phase 3: Now handle any interrupts not captured in local APIC.
213          * This is to account for cases that device interrupted during the time the
214          * rte was being disabled and re-programmed.
215          */
216         for (irq=0; irq < NR_IRQS; irq++) {
217                 if (vectors_in_migration[irq]) {
218                         struct pt_regs *old_regs = set_irq_regs(NULL);
219
220                         vectors_in_migration[irq]=0;
221                         generic_handle_irq(irq);
222                         set_irq_regs(old_regs);
223                 }
224         }
225
226         /*
227          * Now let processor die. We do irq disable and max_xtp() to
228          * ensure there is no more interrupts routed to this processor.
229          * But the local timer interrupt can have 1 pending which we
230          * take care in timer_interrupt().
231          */
232         max_xtp();
233         local_irq_disable();
234 }
235 #endif