54d5d42404
When handling writes to /proc/irq, current code is re-programming rte entries directly. This is not recommended and could potentially cause chipset's to lockup, or cause missing interrupts. CONFIG_IRQ_BALANCE does this correctly, where it re-programs only when the interrupt is pending. The same needs to be done for /proc/irq handling as well. Otherwise user space irq balancers are really not doing the right thing. - Changed pending_irq_balance_cpumask to pending_irq_migrate_cpumask for lack of a generic name. - added move_irq out of IRQ_BALANCE, and added this same to X86_64 - Added new proc handler for write, so we can do deferred write at irq handling time. - Display of /proc/irq/XX/smp_affinity used to display CPU_MASKALL, instead it now shows only active cpu masks, or exactly what was set. - Provided a common move_irq implementation, instead of duplicating when using generic irq framework. Tested on i386/x86_64 and ia64 with CONFIG_PCI_MSI turned on and off. Tested UP builds as well. MSI testing: tbd: I have cards, need to look for a x-over cable, although I did test an earlier version of this patch. Will test in a couple days. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Acked-by: Zwane Mwaikambo <zwane@holomorphy.com> Grudgingly-acked-by: Andi Kleen <ak@muc.de> Signed-off-by: Coywolf Qi Hunt <coywolf@lovecn.org> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
169 lines
3.6 KiB
C
169 lines
3.6 KiB
C
/*
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* linux/kernel/irq/proc.c
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*
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* Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
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*
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* This file contains the /proc/irq/ handling code.
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*/
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#include <linux/irq.h>
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#include <linux/proc_fs.h>
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#include <linux/interrupt.h>
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static struct proc_dir_entry *root_irq_dir, *irq_dir[NR_IRQS];
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#ifdef CONFIG_SMP
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/*
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* The /proc/irq/<irq>/smp_affinity values:
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*/
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static struct proc_dir_entry *smp_affinity_entry[NR_IRQS];
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#ifdef CONFIG_GENERIC_PENDING_IRQ
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void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val)
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{
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/*
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* Save these away for later use. Re-progam when the
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* interrupt is pending
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*/
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set_pending_irq(irq, mask_val);
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}
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#else
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void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val)
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{
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irq_affinity[irq] = mask_val;
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irq_desc[irq].handler->set_affinity(irq, mask_val);
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}
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#endif
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static int irq_affinity_read_proc(char *page, char **start, off_t off,
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int count, int *eof, void *data)
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{
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int len = cpumask_scnprintf(page, count, irq_affinity[(long)data]);
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if (count - len < 2)
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return -EINVAL;
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len += sprintf(page + len, "\n");
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return len;
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}
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int no_irq_affinity;
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static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
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unsigned long count, void *data)
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{
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unsigned int irq = (int)(long)data, full_count = count, err;
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cpumask_t new_value, tmp;
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if (!irq_desc[irq].handler->set_affinity || no_irq_affinity)
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return -EIO;
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err = cpumask_parse(buffer, count, new_value);
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if (err)
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return err;
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/*
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* Do not allow disabling IRQs completely - it's a too easy
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* way to make the system unusable accidentally :-) At least
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* one online CPU still has to be targeted.
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*/
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cpus_and(tmp, new_value, cpu_online_map);
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if (cpus_empty(tmp))
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return -EINVAL;
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proc_set_irq_affinity(irq, new_value);
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return full_count;
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}
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#endif
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#define MAX_NAMELEN 128
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static int name_unique(unsigned int irq, struct irqaction *new_action)
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{
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struct irq_desc *desc = irq_desc + irq;
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struct irqaction *action;
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for (action = desc->action ; action; action = action->next)
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if ((action != new_action) && action->name &&
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!strcmp(new_action->name, action->name))
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return 0;
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return 1;
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}
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void register_handler_proc(unsigned int irq, struct irqaction *action)
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{
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char name [MAX_NAMELEN];
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if (!irq_dir[irq] || action->dir || !action->name ||
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!name_unique(irq, action))
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return;
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memset(name, 0, MAX_NAMELEN);
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snprintf(name, MAX_NAMELEN, "%s", action->name);
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/* create /proc/irq/1234/handler/ */
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action->dir = proc_mkdir(name, irq_dir[irq]);
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}
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#undef MAX_NAMELEN
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#define MAX_NAMELEN 10
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void register_irq_proc(unsigned int irq)
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{
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char name [MAX_NAMELEN];
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if (!root_irq_dir ||
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(irq_desc[irq].handler == &no_irq_type) ||
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irq_dir[irq])
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return;
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memset(name, 0, MAX_NAMELEN);
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sprintf(name, "%d", irq);
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/* create /proc/irq/1234 */
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irq_dir[irq] = proc_mkdir(name, root_irq_dir);
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#ifdef CONFIG_SMP
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{
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struct proc_dir_entry *entry;
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/* create /proc/irq/<irq>/smp_affinity */
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entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
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if (entry) {
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entry->nlink = 1;
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entry->data = (void *)(long)irq;
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entry->read_proc = irq_affinity_read_proc;
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entry->write_proc = irq_affinity_write_proc;
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}
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smp_affinity_entry[irq] = entry;
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}
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#endif
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}
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#undef MAX_NAMELEN
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void unregister_handler_proc(unsigned int irq, struct irqaction *action)
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{
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if (action->dir)
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remove_proc_entry(action->dir->name, irq_dir[irq]);
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}
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void init_irq_proc(void)
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{
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int i;
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/* create /proc/irq */
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root_irq_dir = proc_mkdir("irq", NULL);
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if (!root_irq_dir)
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return;
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/*
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* Create entries for all existing IRQs.
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*/
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for (i = 0; i < NR_IRQS; i++)
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register_irq_proc(i);
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}
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