v4.19.13 snapshot.
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
new file mode 100644
index 0000000..da9addb
--- /dev/null
+++ b/kernel/irq/proc.c
@@ -0,0 +1,529 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains the /proc/irq/ handling code.
+ */
+
+#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_stat.h>
+#include <linux/mutex.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;
+
+ switch (type) {
+ case AFFINITY:
+ case AFFINITY_LIST:
+ mask = desc->irq_common_data.affinity;
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+ if (irqd_is_setaffinity_pending(&desc->irq_data))
+ mask = desc->pending_mask;
+#endif
+ 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);
+ unsigned long flags;
+ cpumask_var_t mask;
+
+ if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+ if (desc->affinity_hint)
+ cpumask_copy(mask, desc->affinity_hint);
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+
+ seq_printf(m, "%*pb\n", cpumask_pr_args(mask));
+ free_cpumask_var(mask);
+
+ return 0;
+}
+
+#ifndef is_affinity_mask_valid
+#define is_affinity_mask_valid(val) 1
+#endif
+
+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);
+}
+
+
+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 -EIO;
+
+ if (!alloc_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;
+
+ if (!is_affinity_mask_valid(new_value)) {
+ err = -EINVAL;
+ 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 file_operations irq_affinity_proc_fops = {
+ .open = irq_affinity_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+ .write = irq_affinity_proc_write,
+};
+
+static const struct file_operations irq_affinity_list_proc_fops = {
+ .open = irq_affinity_list_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+ .write = irq_affinity_list_proc_write,
+};
+
+#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
+static 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 (!alloc_cpumask_var(&new_value, GFP_KERNEL))
+ return -ENOMEM;
+
+ err = cpumask_parse_user(buffer, count, new_value);
+ if (err)
+ goto out;
+
+ if (!is_affinity_mask_valid(new_value)) {
+ err = -EINVAL;
+ 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 file_operations default_affinity_proc_fops = {
+ .open = default_affinity_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+ .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 int name_unique(unsigned int irq, struct irqaction *new_action)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ struct irqaction *action;
+ unsigned long flags;
+ int ret = 1;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+ for_each_action_of_desc(desc, action) {
+ if ((action != new_action) && action->name &&
+ !strcmp(new_action->name, action->name)) {
+ ret = 0;
+ break;
+ }
+ }
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ return ret;
+}
+
+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;
+
+ snprintf(name, MAX_NAMELEN, "%s", action->name);
+
+ /* create /proc/irq/1234/handler/ */
+ action->dir = proc_mkdir(name, desc->dir);
+}
+
+#undef MAX_NAMELEN
+
+#define MAX_NAMELEN 10
+
+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.
+ */
+ mutex_lock(®ister_lock);
+
+ if (desc->dir)
+ goto out_unlock;
+
+ sprintf(name, "%d", irq);
+
+ /* create /proc/irq/1234 */
+ desc->dir = proc_mkdir(name, root_irq_dir);
+ if (!desc->dir)
+ goto out_unlock;
+
+#ifdef CONFIG_SMP
+ /* create /proc/irq/<irq>/smp_affinity */
+ proc_create_data("smp_affinity", 0644, desc->dir,
+ &irq_affinity_proc_fops, 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", 0644, desc->dir,
+ &irq_affinity_list_proc_fops, 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);
+
+out_unlock:
+ mutex_unlock(®ister_lock);
+}
+
+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);
+
+ sprintf(name, "%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_fops);
+#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);
+}
+
+#ifdef CONFIG_GENERIC_IRQ_SHOW
+
+int __weak arch_show_interrupts(struct seq_file *p, int prec)
+{
+ return 0;
+}
+
+#ifndef ACTUAL_NR_IRQS
+# define ACTUAL_NR_IRQS nr_irqs
+#endif
+
+int show_interrupts(struct seq_file *p, void *v)
+{
+ static int prec;
+
+ unsigned long flags, any_count = 0;
+ int i = *(loff_t *) v, j;
+ struct irqaction *action;
+ struct irq_desc *desc;
+
+ if (i > ACTUAL_NR_IRQS)
+ return 0;
+
+ if (i == ACTUAL_NR_IRQS)
+ return arch_show_interrupts(p, prec);
+
+ /* print header and calculate the width of the first column */
+ if (i == 0) {
+ for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
+ j *= 10;
+
+ seq_printf(p, "%*s", prec + 8, "");
+ for_each_online_cpu(j)
+ seq_printf(p, "CPU%-8d", j);
+ seq_putc(p, '\n');
+ }
+
+ rcu_read_lock();
+ desc = irq_to_desc(i);
+ if (!desc)
+ goto outsparse;
+
+ if (desc->kstat_irqs)
+ for_each_online_cpu(j)
+ any_count |= *per_cpu_ptr(desc->kstat_irqs, j);
+
+ if ((!desc->action || irq_desc_is_chained(desc)) && !any_count)
+ goto outsparse;
+
+ seq_printf(p, "%*d: ", prec, i);
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", desc->kstat_irqs ?
+ *per_cpu_ptr(desc->kstat_irqs, j) : 0);
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+ 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, " %8s", desc->irq_data.chip->name);
+ else
+ seq_printf(p, " %8s", "-");
+ } else {
+ seq_printf(p, " %8s", "None");
+ }
+ if (desc->irq_data.domain)
+ seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
+ else
+ seq_printf(p, " %*s", prec, "");
+#ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
+ seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
+#endif
+ 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');
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+outsparse:
+ rcu_read_unlock();
+ return 0;
+}
+#endif