aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/irq/proc.c
diff options
context:
space:
mode:
authorMax Krasnyansky <maxk@qualcomm.com>2008-05-29 14:02:52 -0400
committerThomas Gleixner <tglx@linutronix.de>2008-06-05 09:18:30 -0400
commit18404756765c713a0be4eb1082920c04822ce588 (patch)
treeed426f8fe90bff1ffd854074a2e4b370dd6821f8 /kernel/irq/proc.c
parentc3b25b32e8bef526cca748e1ba023c6bdd705a99 (diff)
genirq: Expose default irq affinity mask (take 3)
Current IRQ affinity interface does not provide a way to set affinity for the IRQs that will be allocated/activated in the future. This patch creates /proc/irq/default_smp_affinity that lets users set default affinity mask for the newly allocated IRQs. Changing the default does not affect affinity masks for the currently active IRQs, they have to be changed explicitly. Updated based on Paul J's comments and added some more documentation. Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Cc: pj@sgi.com Cc: a.p.zijlstra@chello.nl Cc: tglx@linutronix.de Cc: rdunlap@xenotime.net Cc: mingo@elte.hu Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/irq/proc.c')
-rw-r--r--kernel/irq/proc.c59
1 files changed, 55 insertions, 4 deletions
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index c2f2ccb0549a..6c6d35d68ee9 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -44,7 +44,7 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
44 unsigned long count, void *data) 44 unsigned long count, void *data)
45{ 45{
46 unsigned int irq = (int)(long)data, full_count = count, err; 46 unsigned int irq = (int)(long)data, full_count = count, err;
47 cpumask_t new_value, tmp; 47 cpumask_t new_value;
48 48
49 if (!irq_desc[irq].chip->set_affinity || no_irq_affinity || 49 if (!irq_desc[irq].chip->set_affinity || no_irq_affinity ||
50 irq_balancing_disabled(irq)) 50 irq_balancing_disabled(irq))
@@ -62,17 +62,51 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
62 * way to make the system unusable accidentally :-) At least 62 * way to make the system unusable accidentally :-) At least
63 * one online CPU still has to be targeted. 63 * one online CPU still has to be targeted.
64 */ 64 */
65 cpus_and(tmp, new_value, cpu_online_map); 65 if (!cpus_intersects(new_value, cpu_online_map))
66 if (cpus_empty(tmp))
67 /* Special case for empty set - allow the architecture 66 /* Special case for empty set - allow the architecture
68 code to set default SMP affinity. */ 67 code to set default SMP affinity. */
69 return select_smp_affinity(irq) ? -EINVAL : full_count; 68 return irq_select_affinity(irq) ? -EINVAL : full_count;
70 69
71 irq_set_affinity(irq, new_value); 70 irq_set_affinity(irq, new_value);
72 71
73 return full_count; 72 return full_count;
74} 73}
75 74
75static int default_affinity_read(char *page, char **start, off_t off,
76 int count, int *eof, void *data)
77{
78 int len = cpumask_scnprintf(page, count, irq_default_affinity);
79 if (count - len < 2)
80 return -EINVAL;
81 len += sprintf(page + len, "\n");
82 return len;
83}
84
85static int default_affinity_write(struct file *file, const char __user *buffer,
86 unsigned long count, void *data)
87{
88 unsigned int full_count = count, err;
89 cpumask_t new_value;
90
91 err = cpumask_parse_user(buffer, count, new_value);
92 if (err)
93 return err;
94
95 if (!is_affinity_mask_valid(new_value))
96 return -EINVAL;
97
98 /*
99 * Do not allow disabling IRQs completely - it's a too easy
100 * way to make the system unusable accidentally :-) At least
101 * one online CPU still has to be targeted.
102 */
103 if (!cpus_intersects(new_value, cpu_online_map))
104 return -EINVAL;
105
106 irq_default_affinity = new_value;
107
108 return full_count;
109}
76#endif 110#endif
77 111
78static int irq_spurious_read(char *page, char **start, off_t off, 112static int irq_spurious_read(char *page, char **start, off_t off,
@@ -171,6 +205,21 @@ void unregister_handler_proc(unsigned int irq, struct irqaction *action)
171 remove_proc_entry(action->dir->name, irq_desc[irq].dir); 205 remove_proc_entry(action->dir->name, irq_desc[irq].dir);
172} 206}
173 207
208void register_default_affinity_proc(void)
209{
210#ifdef CONFIG_SMP
211 struct proc_dir_entry *entry;
212
213 /* create /proc/irq/default_smp_affinity */
214 entry = create_proc_entry("default_smp_affinity", 0600, root_irq_dir);
215 if (entry) {
216 entry->data = NULL;
217 entry->read_proc = default_affinity_read;
218 entry->write_proc = default_affinity_write;
219 }
220#endif
221}
222
174void init_irq_proc(void) 223void init_irq_proc(void)
175{ 224{
176 int i; 225 int i;
@@ -180,6 +229,8 @@ void init_irq_proc(void)
180 if (!root_irq_dir) 229 if (!root_irq_dir)
181 return; 230 return;
182 231
232 register_default_affinity_proc();
233
183 /* 234 /*
184 * Create entries for all existing IRQs. 235 * Create entries for all existing IRQs.
185 */ 236 */