1 files changed, 538 insertions, 0 deletions
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
new file mode 100644
index 000000000..623b8136e
--- /dev/null
+++ b/kernel/irq/proc.c
@@ -0,0 +1,538 @@
+// 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;
+}
+
+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_AFFINITY
+static 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 -EIO;
+
+	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_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 (!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 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(&register_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_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", 0644, 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);
+
+out_unlock:
+	mutex_unlock(&register_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_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);
+}
+
+#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 || irq_settings_is_hidden(desc))
+		goto outsparse;
+
+	if (desc->kstat_irqs) {
+		for_each_online_cpu(j)
+			any_count |= data_race(*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, " %*lu", prec, 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