Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6
[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 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
108 bool 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
121 unsigned 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  */
127 static 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
175 void 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