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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/irq.h>#include <linux/gfp.h>#include <linux/proc_fs.h>#include <linux/seq_file.h>#include <linux/interrupt.h>#include <linux/kernel.h>#include <linux/kernel_stat.h>#include <linux/mutex.h>#include <linux/string.h>
#include "internals.h"
/* * Access rules: * * procfs protects read/write of /proc/irq/N/ files against a * concurrent free of the interrupt descriptor. remove_proc_entry() * immediately prevents new read/writes to happen and waits for * already running read/write functions to complete. * * We remove the proc entries first and then delete the interrupt * descriptor from the radix tree and free it. So it is guaranteed * that irq_to_desc(N) is valid as long as the read/writes are * permitted by procfs. * * The read from /proc/interrupts is a different problem because there * is no protection. So the lookup and the access to irqdesc * information must be protected by sparse_irq_lock. */static struct proc_dir_entry *root_irq_dir;
#ifdef CONFIG_SMP
enum { AFFINITY, AFFINITY_LIST, EFFECTIVE, EFFECTIVE_LIST,};
static int show_irq_affinity(int type, struct seq_file *m){ struct irq_desc *desc = irq_to_desc((long)m->private); const struct cpumask *mask;
guard(raw_spinlock_irq)(&desc->lock);
switch (type) { case AFFINITY: case AFFINITY_LIST: mask = desc->irq_common_data.affinity; if (irq_move_pending(&desc->irq_data)) mask = irq_desc_get_pending_mask(desc); break; case EFFECTIVE: case EFFECTIVE_LIST:#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK mask = irq_data_get_effective_affinity_mask(&desc->irq_data); break;#endif default: return -EINVAL; }
switch (type) { case AFFINITY_LIST: case EFFECTIVE_LIST: seq_printf(m, "%*pbl\n", cpumask_pr_args(mask)); break; case AFFINITY: case EFFECTIVE: seq_printf(m, "%*pb\n", cpumask_pr_args(mask)); break; } return 0;}
static int irq_affinity_hint_proc_show(struct seq_file *m, void *v){ struct irq_desc *desc = irq_to_desc((long)m->private); cpumask_var_t mask;
if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) return -ENOMEM;
scoped_guard(raw_spinlock_irq, &desc->lock) { if (desc->affinity_hint) cpumask_copy(mask, desc->affinity_hint); }
seq_printf(m, "%*pb\n", cpumask_pr_args(mask)); free_cpumask_var(mask); return 0;}
int no_irq_affinity;static int irq_affinity_proc_show(struct seq_file *m, void *v){ return show_irq_affinity(AFFINITY, m);}
static int irq_affinity_list_proc_show(struct seq_file *m, void *v){ return show_irq_affinity(AFFINITY_LIST, m);}
#ifndef CONFIG_AUTO_IRQ_AFFINITYstatic inline int irq_select_affinity_usr(unsigned int irq){ /* * If the interrupt is started up already then this fails. The * interrupt is assigned to an online CPU already. There is no * point to move it around randomly. Tell user space that the * selected mask is bogus. * * If not then any change to the affinity is pointless because the * startup code invokes irq_setup_affinity() which will select * a online CPU anyway. */ return -EINVAL;}#else/* ALPHA magic affinity auto selector. Keep it for historical reasons. */static inline int irq_select_affinity_usr(unsigned int irq){ return irq_select_affinity(irq);}#endif
static ssize_t write_irq_affinity(int type, struct file *file, const char __user *buffer, size_t count, loff_t *pos){ unsigned int irq = (int)(long)pde_data(file_inode(file)); cpumask_var_t new_value; int err;
if (!irq_can_set_affinity_usr(irq) || no_irq_affinity) return -EPERM;
if (!zalloc_cpumask_var(&new_value, GFP_KERNEL)) return -ENOMEM;
if (type) err = cpumask_parselist_user(buffer, count, new_value); else err = cpumask_parse_user(buffer, count, new_value); if (err) goto free_cpumask;
/* * Do not allow disabling IRQs completely - it's a too easy * way to make the system unusable accidentally :-) At least * one online CPU still has to be targeted. */ if (!cpumask_intersects(new_value, cpu_online_mask)) { /* * Special case for empty set - allow the architecture code * to set default SMP affinity. */ err = irq_select_affinity_usr(irq) ? -EINVAL : count; } else { err = irq_set_affinity(irq, new_value); if (!err) err = count; }
free_cpumask: free_cpumask_var(new_value); return err;}
static ssize_t irq_affinity_proc_write(struct file *file, const char __user *buffer, size_t count, loff_t *pos){ return write_irq_affinity(0, file, buffer, count, pos);}
static ssize_t irq_affinity_list_proc_write(struct file *file, const char __user *buffer, size_t count, loff_t *pos){ return write_irq_affinity(1, file, buffer, count, pos);}
static int irq_affinity_proc_open(struct inode *inode, struct file *file){ return single_open(file, irq_affinity_proc_show, pde_data(inode));}
static int irq_affinity_list_proc_open(struct inode *inode, struct file *file){ return single_open(file, irq_affinity_list_proc_show, pde_data(inode));}
static const struct proc_ops irq_affinity_proc_ops = { .proc_open = irq_affinity_proc_open, .proc_read = seq_read, .proc_lseek = seq_lseek, .proc_release = single_release, .proc_write = irq_affinity_proc_write,};
static const struct proc_ops irq_affinity_list_proc_ops = { .proc_open = irq_affinity_list_proc_open, .proc_read = seq_read, .proc_lseek = seq_lseek, .proc_release = single_release, .proc_write = irq_affinity_list_proc_write,};
#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASKstatic int irq_effective_aff_proc_show(struct seq_file *m, void *v){ return show_irq_affinity(EFFECTIVE, m);}
static int irq_effective_aff_list_proc_show(struct seq_file *m, void *v){ return show_irq_affinity(EFFECTIVE_LIST, m);}#endif
static int default_affinity_show(struct seq_file *m, void *v){ seq_printf(m, "%*pb\n", cpumask_pr_args(irq_default_affinity)); return 0;}
static ssize_t default_affinity_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos){ cpumask_var_t new_value; int err;
if (!zalloc_cpumask_var(&new_value, GFP_KERNEL)) return -ENOMEM;
err = cpumask_parse_user(buffer, count, new_value); if (err) goto out;
/* * Do not allow disabling IRQs completely - it's a too easy * way to make the system unusable accidentally :-) At least * one online CPU still has to be targeted. */ if (!cpumask_intersects(new_value, cpu_online_mask)) { err = -EINVAL; goto out; }
cpumask_copy(irq_default_affinity, new_value); err = count;
out: free_cpumask_var(new_value); return err;}
static int default_affinity_open(struct inode *inode, struct file *file){ return single_open(file, default_affinity_show, pde_data(inode));}
static const struct proc_ops default_affinity_proc_ops = { .proc_open = default_affinity_open, .proc_read = seq_read, .proc_lseek = seq_lseek, .proc_release = single_release, .proc_write = default_affinity_write,};
static int irq_node_proc_show(struct seq_file *m, void *v){ struct irq_desc *desc = irq_to_desc((long) m->private);
seq_printf(m, "%d\n", irq_desc_get_node(desc)); return 0;}#endif
static int irq_spurious_proc_show(struct seq_file *m, void *v){ struct irq_desc *desc = irq_to_desc((long) m->private);
seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n", desc->irq_count, desc->irqs_unhandled, jiffies_to_msecs(desc->last_unhandled)); return 0;}
#define MAX_NAMELEN 128
static bool name_unique(unsigned int irq, struct irqaction *new_action){ struct irq_desc *desc = irq_to_desc(irq); struct irqaction *action;
guard(raw_spinlock_irq)(&desc->lock); for_each_action_of_desc(desc, action) { if ((action != new_action) && action->name && !strcmp(new_action->name, action->name)) return false; } return true;}
void register_handler_proc(unsigned int irq, struct irqaction *action){ char name[MAX_NAMELEN]; struct irq_desc *desc = irq_to_desc(irq);
if (!desc->dir || action->dir || !action->name || !name_unique(irq, action)) return;
strscpy(name, action->name);
/* create /proc/irq/1234/handler/ */ action->dir = proc_mkdir(name, desc->dir);}
#undef MAX_NAMELEN
#define MAX_NAMELEN 11
void register_irq_proc(unsigned int irq, struct irq_desc *desc){ static DEFINE_MUTEX(register_lock); void __maybe_unused *irqp = (void *)(unsigned long) irq; char name [MAX_NAMELEN];
if (!root_irq_dir || (desc->irq_data.chip == &no_irq_chip)) return;
/* * irq directories are registered only when a handler is * added, not when the descriptor is created, so multiple * tasks might try to register at the same time. */ guard(mutex)(®ister_lock);
if (desc->dir) return;
/* create /proc/irq/1234 */ snprintf(name, MAX_NAMELEN, "%u", irq); desc->dir = proc_mkdir(name, root_irq_dir); if (!desc->dir) return;
#ifdef CONFIG_SMP umode_t umode = S_IRUGO;
if (irq_can_set_affinity_usr(desc->irq_data.irq)) umode |= S_IWUSR;
/* create /proc/irq/<irq>/smp_affinity */ proc_create_data("smp_affinity", umode, desc->dir, &irq_affinity_proc_ops, irqp);
/* create /proc/irq/<irq>/affinity_hint */ proc_create_single_data("affinity_hint", 0444, desc->dir, irq_affinity_hint_proc_show, irqp);
/* create /proc/irq/<irq>/smp_affinity_list */ proc_create_data("smp_affinity_list", umode, desc->dir, &irq_affinity_list_proc_ops, irqp);
proc_create_single_data("node", 0444, desc->dir, irq_node_proc_show, irqp);# ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK proc_create_single_data("effective_affinity", 0444, desc->dir, irq_effective_aff_proc_show, irqp); proc_create_single_data("effective_affinity_list", 0444, desc->dir, irq_effective_aff_list_proc_show, irqp);# endif#endif proc_create_single_data("spurious", 0444, desc->dir, irq_spurious_proc_show, (void *)(long)irq);
}
void unregister_irq_proc(unsigned int irq, struct irq_desc *desc){ char name [MAX_NAMELEN];
if (!root_irq_dir || !desc->dir) return;#ifdef CONFIG_SMP remove_proc_entry("smp_affinity", desc->dir); remove_proc_entry("affinity_hint", desc->dir); remove_proc_entry("smp_affinity_list", desc->dir); remove_proc_entry("node", desc->dir);# ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK remove_proc_entry("effective_affinity", desc->dir); remove_proc_entry("effective_affinity_list", desc->dir);# endif#endif remove_proc_entry("spurious", desc->dir);
snprintf(name, MAX_NAMELEN, "%u", irq); remove_proc_entry(name, root_irq_dir);}
#undef MAX_NAMELEN
void unregister_handler_proc(unsigned int irq, struct irqaction *action){ proc_remove(action->dir);}
static void register_default_affinity_proc(void){#ifdef CONFIG_SMP proc_create("irq/default_smp_affinity", 0644, NULL, &default_affinity_proc_ops);#endif}
void init_irq_proc(void){ unsigned int irq; struct irq_desc *desc;
/* create /proc/irq */ root_irq_dir = proc_mkdir("irq", NULL); if (!root_irq_dir) return;
register_default_affinity_proc();
/* * Create entries for all existing IRQs. */ for_each_irq_desc(irq, desc) register_irq_proc(irq, desc);}
void irq_proc_update_valid(struct irq_desc *desc){ u32 set = _IRQ_PROC_VALID;
if (irq_settings_is_hidden(desc) || irq_desc_is_chained(desc) || !desc->action) set = 0;
irq_settings_update_proc_valid(desc, set);}
#ifdef CONFIG_GENERIC_IRQ_SHOW
#define ARCH_PROC_IRQDESC ((void *)0x00001111)
int __weak arch_show_interrupts(struct seq_file *p, int prec){ return 0;}
static DEFINE_RAW_SPINLOCK(irq_proc_constraints_lock);
static struct irq_proc_constraints { bool print_header; unsigned int num_prec; unsigned int chip_width;} irq_proc_constraints __read_mostly = { .num_prec = 4, .chip_width = 8,};
#ifndef ACTUAL_NR_IRQS# define ACTUAL_NR_IRQS total_nr_irqs#endif
void irq_proc_calc_prec(void){ unsigned int prec, n;
for (prec = 4, n = 10000; prec < 10 && n <= total_nr_irqs; ++prec) n *= 10;
guard(raw_spinlock_irqsave)(&irq_proc_constraints_lock); if (prec > irq_proc_constraints.num_prec) WRITE_ONCE(irq_proc_constraints.num_prec, prec);}
void irq_proc_update_chip(const struct irq_chip *chip){ unsigned int len = chip && chip->name ? strlen(chip->name) : 0;
if (!len || len <= READ_ONCE(irq_proc_constraints.chip_width)) return;
/* Can be invoked from interrupt disabled contexts */ guard(raw_spinlock_irqsave)(&irq_proc_constraints_lock); if (len > irq_proc_constraints.chip_width) WRITE_ONCE(irq_proc_constraints.chip_width, len);}
/* Same as seq_put_decimal_ull_width(p, " ", cnt, 10) */#define ZSTR1 " 0"#define ZSTR1_LEN (sizeof(ZSTR1) - 1)#define ZSTR16 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 \ ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1#define ZSTR256 ZSTR16 ZSTR16 ZSTR16 ZSTR16 ZSTR16 ZSTR16 ZSTR16 ZSTR16 \ ZSTR16 ZSTR16 ZSTR16 ZSTR16 ZSTR16 ZSTR16 ZSTR16 ZSTR16
static inline void irq_proc_emit_zero_counts(struct seq_file *p, unsigned int zeros){ if (!zeros) return;
for (unsigned int n = min(zeros, 256); n; zeros -= n, n = min(zeros, 256)) seq_write(p, ZSTR256, n * ZSTR1_LEN);}
static inline unsigned int irq_proc_emit_count(struct seq_file *p, unsigned int cnt, unsigned int zeros){ if (!cnt) return zeros + 1;
irq_proc_emit_zero_counts(p, zeros); seq_put_decimal_ull_width(p, " ", cnt, 10); return 0;}
void irq_proc_emit_counts(struct seq_file *p, unsigned int __percpu *cnts){ unsigned int cpu, zeros = 0;
for_each_online_cpu(cpu) zeros = irq_proc_emit_count(p, per_cpu(*cnts, cpu), zeros); irq_proc_emit_zero_counts(p, zeros);}
static int irq_seq_show(struct seq_file *p, void *v){ struct irq_proc_constraints *constr = p->private; struct irq_desc *desc = v; struct irqaction *action;
/* Print header for the first interrupt? */ if (constr->print_header) { unsigned int cpu;
seq_printf(p, "%*s", constr->num_prec + 8, ""); for_each_online_cpu(cpu) seq_printf(p, "CPU%-8d", cpu); seq_putc(p, '\n'); constr->print_header = false; }
if (desc == ARCH_PROC_IRQDESC) return arch_show_interrupts(p, constr->num_prec);
seq_put_decimal_ull_width(p, "", irq_desc_get_irq(desc), constr->num_prec); seq_putc(p, ':');
/* * Always output per CPU interrupts. Output device interrupts only when * desc::tot_count is not zero. */ if (irq_settings_is_per_cpu(desc) || irq_settings_is_per_cpu_devid(desc) || data_race(desc->tot_count)) irq_proc_emit_counts(p, &desc->kstat_irqs->cnt); else irq_proc_emit_zero_counts(p, num_online_cpus());
/* Enforce a visual gap */ seq_write(p, " ", 2);
guard(raw_spinlock_irq)(&desc->lock); if (desc->irq_data.chip) { if (desc->irq_data.chip->irq_print_chip) desc->irq_data.chip->irq_print_chip(&desc->irq_data, p); else if (desc->irq_data.chip->name) seq_printf(p, "%-*s", constr->chip_width, desc->irq_data.chip->name); else seq_printf(p, "%-*s", constr->chip_width, "-"); } else { seq_printf(p, "%-*s", constr->chip_width, "None"); }
seq_putc(p, ' '); if (desc->irq_data.domain) seq_put_decimal_ull_width(p, "", desc->irq_data.hwirq, constr->num_prec); else seq_printf(p, " %*s", constr->num_prec, "");
if (IS_ENABLED(CONFIG_GENERIC_IRQ_SHOW_LEVEL)) seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
if (desc->name) seq_printf(p, "-%-8s", desc->name);
action = desc->action; if (action) { seq_printf(p, " %s", action->name); while ((action = action->next) != NULL) seq_printf(p, ", %s", action->name); }
seq_putc(p, '\n'); return 0;}
static void *irq_seq_next_desc(loff_t *pos){ if (*pos > total_nr_irqs) return NULL;
guard(rcu)(); for (;;) { struct irq_desc *desc = irq_find_desc_at_or_after((unsigned int) *pos);
if (desc) { *pos = irq_desc_get_irq(desc); /* * If valid for output then try to acquire a reference * count on the descriptor so that it can't be freed * after dropping RCU read lock on return. */ if (irq_settings_proc_valid(desc) && irq_desc_get_ref(desc)) return desc; (*pos)++; } else { *pos = total_nr_irqs; return ARCH_PROC_IRQDESC; } }}
static void *irq_seq_start(struct seq_file *f, loff_t *pos){ if (!*pos) { struct irq_proc_constraints *constr = f->private;
constr->num_prec = READ_ONCE(irq_proc_constraints.num_prec); constr->chip_width = READ_ONCE(irq_proc_constraints.chip_width); constr->print_header = true; } return irq_seq_next_desc(pos);}
static void *irq_seq_next(struct seq_file *f, void *v, loff_t *pos){ if (v && v != ARCH_PROC_IRQDESC) irq_desc_put_ref(v);
(*pos)++; return irq_seq_next_desc(pos);}
static void irq_seq_stop(struct seq_file *f, void *v){ if (v && v != ARCH_PROC_IRQDESC) irq_desc_put_ref(v);}
static const struct seq_operations irq_seq_ops = { .start = irq_seq_start, .next = irq_seq_next, .stop = irq_seq_stop, .show = irq_seq_show,};
static int __init irq_proc_init(void){ proc_create_seq_private("interrupts", 0, NULL, &irq_seq_ops, sizeof(irq_proc_constraints), NULL); return 0;}fs_initcall(irq_proc_init);
#endif