patch-2.4.19 linux-2.4.19/arch/mips/kernel/irq.c

• Lines: 434
• Date: Fri Aug 2 17:39:43 2002
• Orig file: linux-2.4.18/arch/mips/kernel/irq.c
• Orig date: Sun Sep 9 10:43:01 2001

diff -urN linux-2.4.18/arch/mips/kernel/irq.c linux-2.4.19/arch/mips/kernel/irq.c
@@ -8,17 +8,22 @@
  * Copyright (C) 1992 Linus Torvalds
  * Copyright (C) 1994 - 2000 Ralf Baechle
  */
+#include <linux/config.h>
 #include <linux/kernel.h>
-#include <linux/irq.h>
+#include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/random.h>
 #include <linux/sched.h>
 
+#include <asm/atomic.h>
 #include <asm/system.h>
+#include <asm/uaccess.h>
 
 /*
  * Controller mappings for all interrupt sources:
@@ -63,7 +68,7 @@
 	end_none
 };
 
-volatile unsigned long irq_err_count, spurious_count;
+atomic_t irq_err_count;
 
 /*
  * Generic, controller-independent functions:
@@ -71,13 +76,13 @@
 
 int get_irq_list(char *buf)
 {
+	int i, j;
 	struct irqaction * action;
 	char *p = buf;
-	int i;
 
 	p += sprintf(p, "           ");
-	for (i=0; i < 1 /*smp_num_cpus*/; i++)
-		p += sprintf(p, "CPU%d       ", i);
+	for (j=0; j<smp_num_cpus; j++)
+		p += sprintf(p, "CPU%d       ",j);
 	*p++ = '\n';
 
 	for (i = 0 ; i < NR_IRQS ; i++) {
@@ -85,7 +90,13 @@
 		if (!action) 
 			continue;
 		p += sprintf(p, "%3d: ",i);
+#ifndef CONFIG_SMP
 		p += sprintf(p, "%10u ", kstat_irqs(i));
+#else
+		for (j = 0; j < smp_num_cpus; j++)
+			p += sprintf(p, "%10u ",
+				kstat.irqs[cpu_logical_map(j)][i]);
+#endif
 		p += sprintf(p, " %14s", irq_desc[i].handler->typename);
 		p += sprintf(p, "  %s", action->name);
 
@@ -93,10 +104,182 @@
 			p += sprintf(p, ", %s", action->name);
 		*p++ = '\n';
 	}
-	p += sprintf(p, "ERR: %10lu\n", irq_err_count);
+	p += sprintf(p, "\n");
+	p += sprintf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
 	return p - buf;
 }
 
+#ifdef CONFIG_SMP
+int global_irq_holder = NO_PROC_ID;
+spinlock_t global_irq_lock = SPIN_LOCK_UNLOCKED;
+
+/*
+ * Most of this code is take from the mips64 tree (ip27-irq.c).  It's virtually
+ * identical to the i386 implentation in arh/i386/irq.c, with translations for
+ * the interrupt enable bit
+ */
+
+#define MAXCOUNT 		100000000
+#define SYNC_OTHER_CORES(x)	udelay(x+1)
+
+static inline void wait_on_irq(int cpu)
+{
+	int count = MAXCOUNT;
+
+	for (;;) {
+
+		/*
+		 * Wait until all interrupts are gone. Wait
+		 * for bottom half handlers unless we're
+		 * already executing in one..
+		 */
+		if (!irqs_running())
+			if (local_bh_count(cpu) || !spin_is_locked(&global_bh_lock))
+				break;
+
+		/* Duh, we have to loop. Release the lock to avoid deadlocks */
+		spin_unlock(&global_irq_lock);
+
+		for (;;) {
+			if (!--count) {
+				printk("Count spun out.  Huh?\n");
+				count = ~0;
+			}
+			__sti();
+			SYNC_OTHER_CORES(cpu);
+			__cli();
+			if (irqs_running())
+				continue;
+			if (spin_is_locked(&global_irq_lock))
+				continue;
+			if (!local_bh_count(cpu) && spin_is_locked(&global_bh_lock))
+				continue;
+			if (spin_trylock(&global_irq_lock))
+				break;
+		}
+	}
+}
+
+/*
+ * This is called when we want to synchronize with
+ * interrupts. We may for example tell a device to
+ * stop sending interrupts: but to make sure there
+ * are no interrupts that are executing on another
+ * CPU we need to call this function.
+ */
+void synchronize_irq(void)
+{
+	if (irqs_running()) {
+		/* Stupid approach */
+		cli();
+		sti();
+	}
+}
+
+static inline void get_irqlock(int cpu)
+{
+	if (!spin_trylock(&global_irq_lock)) {
+		/* do we already hold the lock? */
+		if ((unsigned char) cpu == global_irq_holder)
+			return;
+		/* Uhhuh.. Somebody else got it. Wait.. */
+		spin_lock(&global_irq_lock);
+	}
+	/*
+	 * We also to make sure that nobody else is running
+	 * in an interrupt context.
+	 */
+	wait_on_irq(cpu);
+
+	/*
+	 * Ok, finally..
+	 */
+	global_irq_holder = cpu;
+}
+
+/*
+ * A global "cli()" while in an interrupt context turns into just a local 
+ * cli(). Interrupts should use spinlocks for the (very unlikely) case that 
+ * they ever want to protect against each other.
+ * 
+ * If we already have local interrupts disabled, this will not turn a local 
+ * disable into a global one (problems with spinlocks: this makes 
+ * save_flags+cli+sti usable inside a spinlock).
+ */
+
+void __global_cli(void)
+{
+	unsigned int flags;
+
+	__save_flags(flags);
+	if (flags & ST0_IE) {
+		int cpu = smp_processor_id();
+		__cli();
+		if (!local_irq_count(cpu))
+			get_irqlock(cpu);
+	}
+}
+
+void __global_sti(void)
+{
+	int cpu = smp_processor_id();
+
+	if (!local_irq_count(cpu))
+		release_irqlock(cpu);
+	__sti();
+}
+
+/*
+ * SMP flags value to restore to:
+ * 0 - global cli
+ * 1 - global sti
+ * 2 - local cli
+ * 3 - local sti
+ */
+unsigned long __global_save_flags(void)
+{
+	int retval;
+	int local_enabled;
+	unsigned long flags;
+	int cpu = smp_processor_id();
+
+	__save_flags(flags);
+	local_enabled = (flags & ST0_IE);
+	/* default to local */
+	retval = 2 + local_enabled;
+
+	/* check for global flags if we're not in an interrupt */
+	if (!local_irq_count(cpu)) {
+		if (local_enabled)
+			retval = 1;
+		if (global_irq_holder == cpu)
+			retval = 0;
+	}
+
+	return retval;
+}
+
+void __global_restore_flags(unsigned long flags)
+{
+	switch (flags) {
+		case 0:
+			__global_cli();
+			break;
+		case 1:
+			__global_sti();
+			break;
+		case 2:
+			__cli();
+			break;
+		case 3:
+			__sti();
+			break;
+		default:
+			printk("global_restore_flags: %08lx\n", flags);
+	}
+}
+#endif /* CONFIG_SMP */
+
 /*
  * This should really return information about whether
  * we should do bottom half handling etc. Right now we
@@ -690,7 +873,7 @@
 	}
 	spin_unlock_irqrestore(&desc->lock,flags);
 
-	/* register_irq_proc(irq); */
+	register_irq_proc(irq);
 	return 0;
 }
 
@@ -705,3 +888,176 @@
 		irq_desc[i].handler = &no_irq_type;
 	}
 }
+
+EXPORT_SYMBOL(disable_irq_nosync);
+EXPORT_SYMBOL(disable_irq);
+EXPORT_SYMBOL(enable_irq);
+EXPORT_SYMBOL(probe_irq_mask);
+
+static struct proc_dir_entry * root_irq_dir;
+static struct proc_dir_entry * irq_dir [NR_IRQS];
+
+#define HEX_DIGITS 8
+
+static unsigned int parse_hex_value (const char *buffer,
+		unsigned long count, unsigned long *ret)
+{
+	unsigned char hexnum [HEX_DIGITS];
+	unsigned long value;
+	int i;
+
+	if (!count)
+		return -EINVAL;
+	if (count > HEX_DIGITS)
+		count = HEX_DIGITS;
+	if (copy_from_user(hexnum, buffer, count))
+		return -EFAULT;
+
+	/*
+	 * Parse the first 8 characters as a hex string, any non-hex char
+	 * is end-of-string. '00e1', 'e1', '00E1', 'E1' are all the same.
+	 */
+	value = 0;
+
+	for (i = 0; i < count; i++) {
+		unsigned int c = hexnum[i];
+
+		switch (c) {
+			case '0' ... '9': c -= '0'; break;
+			case 'a' ... 'f': c -= 'a'-10; break;
+			case 'A' ... 'F': c -= 'A'-10; break;
+		default:
+			goto out;
+		}
+		value = (value << 4) | c;
+	}
+out:
+	*ret = value;
+	return 0;
+}
+
+#if CONFIG_SMP
+
+static struct proc_dir_entry * smp_affinity_entry [NR_IRQS];
+
+static unsigned long irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = ~0UL };
+static int irq_affinity_read_proc (char *page, char **start, off_t off,
+			int count, int *eof, void *data)
+{
+	if (count < HEX_DIGITS+1)
+		return -EINVAL;
+	return sprintf (page, "%08lx\n", irq_affinity[(long)data]);
+}
+
+static int irq_affinity_write_proc (struct file *file, const char *buffer,
+					unsigned long count, void *data)
+{
+	int irq = (long) data, full_count = count, err;
+	unsigned long new_value;
+
+	if (!irq_desc[irq].handler->set_affinity)
+		return -EIO;
+
+	err = parse_hex_value(buffer, count, &new_value);
+
+	/*
+	 * 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 (!(new_value & cpu_online_map))
+		return -EINVAL;
+
+	irq_affinity[irq] = new_value;
+	irq_desc[irq].handler->set_affinity(irq, new_value);
+
+	return full_count;
+}
+
+#endif
+
+static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
+			int count, int *eof, void *data)
+{
+	unsigned long *mask = (unsigned long *) data;
+	if (count < HEX_DIGITS+1)
+		return -EINVAL;
+	return sprintf (page, "%08lx\n", *mask);
+}
+
+static int prof_cpu_mask_write_proc (struct file *file, const char *buffer,
+					unsigned long count, void *data)
+{
+	unsigned long *mask = (unsigned long *) data, full_count = count, err;
+	unsigned long new_value;
+
+	err = parse_hex_value(buffer, count, &new_value);
+	if (err)
+		return err;
+
+	*mask = new_value;
+	return full_count;
+}
+
+#define MAX_NAMELEN 10
+
+static void register_irq_proc (unsigned int irq)
+{
+	char name [MAX_NAMELEN];
+
+	if (!root_irq_dir || (irq_desc[irq].handler == &no_irq_type) ||
+			irq_dir[irq])
+		return;
+
+	memset(name, 0, MAX_NAMELEN);
+	sprintf(name, "%d", irq);
+
+	/* create /proc/irq/1234 */
+	irq_dir[irq] = proc_mkdir(name, root_irq_dir);
+
+#if CONFIG_SMP
+	{
+		struct proc_dir_entry *entry;
+
+		/* create /proc/irq/1234/smp_affinity */
+		entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
+
+		if (entry) {
+			entry->nlink = 1;
+			entry->data = (void *)(long)irq;
+			entry->read_proc = irq_affinity_read_proc;
+			entry->write_proc = irq_affinity_write_proc;
+		}
+
+		smp_affinity_entry[irq] = entry;
+	}
+#endif
+}
+
+unsigned long prof_cpu_mask = -1;
+
+void init_irq_proc (void)
+{
+	struct proc_dir_entry *entry;
+	int i;
+
+	/* create /proc/irq */
+	root_irq_dir = proc_mkdir("irq", 0);
+
+	/* create /proc/irq/prof_cpu_mask */
+	entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir);
+
+	if (!entry)
+	    return;
+
+	entry->nlink = 1;
+	entry->data = (void *)&prof_cpu_mask;
+	entry->read_proc = prof_cpu_mask_read_proc;
+	entry->write_proc = prof_cpu_mask_write_proc;
+
+	/*
+	 * Create entries for all existing IRQs.
+	 */
+	for (i = 0; i < NR_IRQS; i++)
+		register_irq_proc(i);
+}