1 files changed, 129 insertions, 0 deletions
diff --git a/linux/src/kernel/resource.c b/linux/src/kernel/resource.c
new file mode 100644
index 0000000..7d7a4ad
--- /dev/null
+++ b/linux/src/kernel/resource.c
@@ -0,0 +1,129 @@
+/*
+ *	linux/kernel/resource.c
+ *
+ * Copyright (C) 1995	Linus Torvalds
+ *			David Hinds
+ *
+ * Kernel io-region resource management
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/ioport.h>
+
+#define IOTABLE_SIZE 128
+
+typedef struct resource_entry_t {
+	u_long from, num;
+	const char *name;
+	struct resource_entry_t *next;
+} resource_entry_t;
+
+static resource_entry_t iolist = { 0, 0, "", NULL };
+
+static resource_entry_t iotable[IOTABLE_SIZE];
+
+/*
+ * This generates the report for /proc/ioports
+ */
+int get_ioport_list(char *buf)
+{
+	resource_entry_t *p;
+	int len = 0;
+
+	for (p = iolist.next; (p) && (len < 4000); p = p->next)
+		len += sprintf(buf+len, "%04lx-%04lx : %s\n",
+			   p->from, p->from+p->num-1, p->name);
+	if (p)
+		len += sprintf(buf+len, "4K limit reached!\n");
+	return len;
+}
+
+/*
+ * The workhorse function: find where to put a new entry
+ */
+static resource_entry_t *find_gap(resource_entry_t *root,
+				  u_long from, u_long num)
+{
+	unsigned long flags;
+	resource_entry_t *p;
+	
+	if (from > from+num-1)
+		return NULL;
+	save_flags(flags);
+	cli();
+	for (p = root; ; p = p->next) {
+		if ((p != root) && (p->from+p->num-1 >= from)) {
+			p = NULL;
+			break;
+		}
+		if ((p->next == NULL) || (p->next->from > from+num-1))
+			break;
+	}
+	restore_flags(flags);
+	return p;
+}
+
+/*
+ * Call this from the device driver to register the ioport region.
+ */
+void request_region(unsigned int from, unsigned int num, const char *name)
+{
+	resource_entry_t *p;
+	int i;
+
+	for (i = 0; i < IOTABLE_SIZE; i++)
+		if (iotable[i].num == 0)
+			break;
+	if (i == IOTABLE_SIZE)
+		printk("warning: ioport table is full\n");
+	else {
+		p = find_gap(&iolist, from, num);
+		if (p == NULL)
+			return;
+		iotable[i].name = name;
+		iotable[i].from = from;
+		iotable[i].num = num;
+		iotable[i].next = p->next;
+		p->next = &iotable[i];
+		return;
+	}
+}
+
+/* 
+ * Call this when the device driver is unloaded
+ */
+void release_region(unsigned int from, unsigned int num)
+{
+	resource_entry_t *p, *q;
+
+	for (p = &iolist; ; p = q) {
+		q = p->next;
+		if (q == NULL)
+			break;
+		if ((q->from == from) && (q->num == num)) {
+			q->num = 0;
+			p->next = q->next;
+			return;
+		}
+	}
+}
+
+/*
+ * Call this to check the ioport region before probing
+ */
+int check_region(unsigned int from, unsigned int num)
+{
+	return (find_gap(&iolist, from, num) == NULL) ? -EBUSY : 0;
+}
+
+/* Called from init/main.c to reserve IO ports. */
+void reserve_setup(char *str, int *ints)
+{
+	int i;
+
+	for (i = 1; i < ints[0]; i += 2)
+		request_region(ints[i], ints[i+1], "reserved");
+}