[PATCH] Generic hardware RNG support

[Michael Buesch <mbuesch@freenet.de>]

[-- Attachment #1.1: Type: text/plain, Size: 21951 bytes --]

Andrew, consider inclusion of the following patch into -mm
for further testing, please.

---

This patch adds support for generic Hardware Random Number Generator
drivers. This makes the usage of the bcm43xx internal RNG through
/dev/hwrandom possible.

A patch against bcm43xx for your testing pleasure can be found at:
ftp://ftp.bu3sch.de/misc/bcm43xx-d80211-hwrng.patch


diff -urNX 2.6.16-rc4-mm2/Documentation/dontdiff 2.6.16-rc4-mm2.orig/drivers/char/hw_random.c 2.6.16-rc4-mm2/drivers/char/hw_random.c
--- 2.6.16-rc4-mm2.orig/drivers/char/hw_random.c	2006-02-28 11:54:50.000000000 +0100
+++ 2.6.16-rc4-mm2/drivers/char/hw_random.c	2006-02-28 12:07:56.000000000 +0100
@@ -18,6 +18,9 @@
 	Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
 	Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
 
+	Added generic RNG API
+	Copyright 2006 Michael Buesch <mbuesch@freenet.de>
+
 	Please read Documentation/hw_random.txt for details on use.
 
 	----------------------------------------------------------
@@ -27,11 +30,12 @@
  */
 
 
+#include <linux/hw_random.h>
+#include <linux/pci.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/init.h>
-#include <linux/pci.h>
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
 #include <linux/random.h>
@@ -49,13 +53,9 @@
 #include <asm/uaccess.h>
 
 
-/*
- * core module and version information
- */
-#define RNG_VERSION "1.0.0"
-#define RNG_MODULE_NAME "hw_random"
-#define RNG_DRIVER_NAME   RNG_MODULE_NAME " hardware driver " RNG_VERSION
-#define PFX RNG_MODULE_NAME ": "
+#define RNG_MODULE_NAME		"hw_random"
+#define RNG_DRIVER_NAME		RNG_MODULE_NAME " hardware driver"
+#define PFX RNG_MODULE_NAME	": "
 
 
 /*
@@ -83,36 +83,31 @@
 static ssize_t rng_dev_read (struct file *filp, char __user *buf, size_t size,
 				loff_t * offp);
 
-static int __init intel_init (struct pci_dev *dev);
-static void intel_cleanup(void);
-static unsigned int intel_data_present (void);
-static u32 intel_data_read (void);
-
-static int __init amd_init (struct pci_dev *dev);
-static void amd_cleanup(void);
-static unsigned int amd_data_present (void);
-static u32 amd_data_read (void);
+static int __init intel_init (struct hwrng *rng);
+static void intel_cleanup(struct hwrng *rng);
+static unsigned int intel_data_present (struct hwrng *rng);
+static u32 intel_data_read (struct hwrng *rng);
+
+static int __init amd_init (struct hwrng *rng);
+static void amd_cleanup(struct hwrng *rng);
+static unsigned int amd_data_present (struct hwrng *rng);
+static u32 amd_data_read (struct hwrng *rng);
 
 #ifdef __i386__
-static int __init via_init(struct pci_dev *dev);
-static void via_cleanup(void);
-static unsigned int via_data_present (void);
-static u32 via_data_read (void);
+static int __init via_init(struct hwrng *rng);
+static void via_cleanup(struct hwrng *rng);
+static unsigned int via_data_present (struct hwrng *rng);
+static u32 via_data_read (struct hwrng *rng);
 #endif
 
-static int __init geode_init(struct pci_dev *dev);
-static void geode_cleanup(void);
-static unsigned int geode_data_present (void);
-static u32 geode_data_read (void);
-
-struct rng_operations {
-	int (*init) (struct pci_dev *dev);
-	void (*cleanup) (void);
-	unsigned int (*data_present) (void);
-	u32 (*data_read) (void);
-	unsigned int n_bytes; /* number of bytes per ->data_read */
-};
-static struct rng_operations *rng_ops;
+static int __init geode_init(struct hwrng *rng);
+static void geode_cleanup(struct hwrng *rng);
+static unsigned int geode_data_present (struct hwrng *rng);
+static u32 geode_data_read (struct hwrng *rng);
+
+static struct hwrng *current_rng;
+static LIST_HEAD(rng_list);
+static DEFINE_MUTEX(rng_mutex);
 
 static struct file_operations rng_chrdev_ops = {
 	.owner		= THIS_MODULE,
@@ -122,9 +117,9 @@
 
 
 static struct miscdevice rng_miscdev = {
-	RNG_MISCDEV_MINOR,
-	RNG_MODULE_NAME,
-	&rng_chrdev_ops,
+	.minor		= RNG_MISCDEV_MINOR,
+	.name		= RNG_MODULE_NAME,
+	.fops		= &rng_chrdev_ops,
 };
 
 enum {
@@ -135,24 +130,41 @@
 	rng_hw_geode,
 };
 
-static struct rng_operations rng_vendor_ops[] = {
-	/* rng_hw_none */
-	{ },
-
-	/* rng_hw_intel */
-	{ intel_init, intel_cleanup, intel_data_present,
-	  intel_data_read, 1 },
-
-	/* rng_hw_amd */
-	{ amd_init, amd_cleanup, amd_data_present, amd_data_read, 4 },
-
+static struct hwrng rng_vendor_ops[] = {
+	{ /* rng_hw_none */
+	}, { /* rng_hw_intel */
+		.name		= "intel",
+		.init		= intel_init,
+		.cleanup	= intel_cleanup,
+		.data_present	= intel_data_present,
+		.data_read	= intel_data_read,
+		.n_bytes	= 1,
+	}, { /* rng_hw_amd */
+		.name		= "amd",
+		.init		= amd_init,
+		.cleanup	= amd_cleanup,
+		.data_present	= amd_data_present,
+		.data_read	= amd_data_read,
+		.n_bytes	= 4,
+	},
 #ifdef __i386__
-	/* rng_hw_via */
-	{ via_init, via_cleanup, via_data_present, via_data_read, 1 },
+	{ /* rng_hw_via */
+		.name		= "via",
+		.init		= via_init,
+		.cleanup	= via_cleanup,
+		.data_present	= via_data_present,
+		.data_read	= via_data_read,
+		.n_bytes	= 1,
+	},
 #endif
-
-	/* rng_hw_geode */
-	{ geode_init, geode_cleanup, geode_data_present, geode_data_read, 4 }
+	{ /* rng_hw_geode */
+		.name		= "geode",
+		.init		= geode_init,
+		.cleanup	= geode_cleanup,
+		.data_present	= geode_data_present,
+		.data_read	= geode_data_read,
+		.n_bytes	= 4,
+	},
 };
 
 /*
@@ -204,39 +216,39 @@
 #define INTEL_RNG_ADDR				0xFFBC015F
 #define INTEL_RNG_ADDR_LEN			3
 
-/* token to our ioremap'd RNG register area */
-static void __iomem *rng_mem;
-
-static inline u8 intel_hwstatus (void)
+static inline u8 intel_hwstatus (void __iomem *rng_mem)
 {
 	assert (rng_mem != NULL);
 	return readb (rng_mem + INTEL_RNG_HW_STATUS);
 }
 
-static inline u8 intel_hwstatus_set (u8 hw_status)
+static inline u8 intel_hwstatus_set (void __iomem *rng_mem, u8 hw_status)
 {
 	assert (rng_mem != NULL);
 	writeb (hw_status, rng_mem + INTEL_RNG_HW_STATUS);
-	return intel_hwstatus ();
+	return intel_hwstatus (rng_mem);
 }
 
-static unsigned int intel_data_present(void)
+static unsigned int intel_data_present(struct hwrng *rng)
 {
-	assert (rng_mem != NULL);
+	void __iomem *rng_mem = (void __iomem *)rng->priv;
 
+	assert (rng_mem != NULL);
 	return (readb (rng_mem + INTEL_RNG_STATUS) & INTEL_RNG_DATA_PRESENT) ?
 		1 : 0;
 }
 
-static u32 intel_data_read(void)
+static u32 intel_data_read(struct hwrng *rng)
 {
-	assert (rng_mem != NULL);
+	void __iomem *rng_mem = (void __iomem *)rng->priv;
 
+	assert (rng_mem != NULL);
 	return readb (rng_mem + INTEL_RNG_DATA);
 }
 
-static int __init intel_init (struct pci_dev *dev)
+static int __init intel_init(struct hwrng *rng)
 {
+	void __iomem *rng_mem;
 	int rc;
 	u8 hw_status;
 
@@ -248,9 +260,10 @@
 		rc = -EBUSY;
 		goto err_out;
 	}
+	rng->priv = (unsigned long)rng_mem;
 
 	/* Check for Intel 82802 */
-	hw_status = intel_hwstatus ();
+	hw_status = intel_hwstatus (rng_mem);
 	if ((hw_status & INTEL_RNG_PRESENT) == 0) {
 		printk (KERN_ERR PFX "RNG not detected\n");
 		rc = -ENODEV;
@@ -259,7 +272,7 @@
 
 	/* turn RNG h/w on, if it's off */
 	if ((hw_status & INTEL_RNG_ENABLED) == 0)
-		hw_status = intel_hwstatus_set (hw_status | INTEL_RNG_ENABLED);
+		hw_status = intel_hwstatus_set (rng_mem, hw_status | INTEL_RNG_ENABLED);
 	if ((hw_status & INTEL_RNG_ENABLED) == 0) {
 		printk (KERN_ERR PFX "cannot enable RNG, aborting\n");
 		rc = -EIO;
@@ -271,23 +284,22 @@
 
 err_out_free_map:
 	iounmap (rng_mem);
-	rng_mem = NULL;
 err_out:
 	DPRINTK ("EXIT, returning %d\n", rc);
 	return rc;
 }
 
-static void intel_cleanup(void)
+static void intel_cleanup(struct hwrng *rng)
 {
+	void __iomem *rng_mem = (void __iomem *)rng->priv;
 	u8 hw_status;
 
-	hw_status = intel_hwstatus ();
+	hw_status = intel_hwstatus (rng_mem);
 	if (hw_status & INTEL_RNG_ENABLED)
-		intel_hwstatus_set (hw_status & ~INTEL_RNG_ENABLED);
+		intel_hwstatus_set (rng_mem, hw_status & ~INTEL_RNG_ENABLED);
 	else
 		printk(KERN_WARNING PFX "unusual: RNG already disabled\n");
 	iounmap(rng_mem);
-	rng_mem = NULL;
 }
 
 /***********************************************************************
@@ -296,22 +308,25 @@
  *
  */
 
-static u32 pmbase;			/* PMxx I/O base */
-static struct pci_dev *amd_dev;
-
-static unsigned int amd_data_present (void)
+static unsigned int amd_data_present (struct hwrng *rng)
 {
+	u32 pmbase = (u32)rng->priv;
+
       	return inl(pmbase + 0xF4) & 1;
 }
 
 
-static u32 amd_data_read (void)
+static u32 amd_data_read (struct hwrng *rng)
 {
+	u32 pmbase = (u32)rng->priv;
+
 	return inl(pmbase + 0xF0);
 }
 
-static int __init amd_init (struct pci_dev *dev)
+static int __init amd_init(struct hwrng *rng)
 {
+	u32 pmbase;
+	struct pci_dev *dev = rng->dev;
 	int rc;
 	u8 rnen;
 
@@ -327,6 +342,7 @@
 		rc = -EIO;
 		goto err_out;
 	}
+	rng->priv = (unsigned long)pmbase;
 
 	pci_read_config_byte(dev, 0x40, &rnen);
 	rnen |= (1 << 7);	/* RNG on */
@@ -339,8 +355,6 @@
 	pr_info( PFX "AMD768 system management I/O registers at 0x%X.\n",
 			pmbase);
 
-	amd_dev = dev;
-
 	DPRINTK ("EXIT, returning 0\n");
 	return 0;
 
@@ -349,13 +363,13 @@
 	return rc;
 }
 
-static void amd_cleanup(void)
+static void amd_cleanup(struct hwrng *rng)
 {
 	u8 rnen;
 
-	pci_read_config_byte(amd_dev, 0x40, &rnen);
+	pci_read_config_byte(rng->dev, 0x40, &rnen);
 	rnen &= ~(1 << 7);	/* RNG off */
-	pci_write_config_byte(amd_dev, 0x40, rnen);
+	pci_write_config_byte(rng->dev, 0x40, rnen);
 
 	/* FIXME: twiddle pmio, also? */
 }
@@ -384,8 +398,6 @@
 	VIA_RNG_CHUNK_1_MASK	= 0xFF,
 };
 
-static u32 via_rng_datum;
-
 /*
  * Investigate using the 'rep' prefix to obtain 32 bits of random data
  * in one insn.  The upside is potentially better performance.  The
@@ -411,9 +423,10 @@
 	return eax_out;
 }
 
-static unsigned int via_data_present(void)
+static unsigned int via_data_present(struct hwrng *rng)
 {
 	u32 bytes_out;
+	u32 *via_rng_datum = (u32 *)(&rng->priv);
 
 	/* We choose the recommended 1-byte-per-instruction RNG rate,
 	 * for greater randomness at the expense of speed.  Larger
@@ -427,20 +440,23 @@
 	 * A copy of MSR_VIA_RNG is placed in eax_out when xstore
 	 * completes.
 	 */
-	via_rng_datum = 0; /* paranoia, not really necessary */
-	bytes_out = xstore(&via_rng_datum, VIA_RNG_CHUNK_1) & VIA_XSTORE_CNT_MASK;
+
+	*via_rng_datum = 0; /* paranoia, not really necessary */
+	bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1) & VIA_XSTORE_CNT_MASK;
 	if (bytes_out == 0)
 		return 0;
 
 	return 1;
 }
 
-static u32 via_data_read(void)
+static u32 via_data_read(struct hwrng *rng)
 {
+	u32 via_rng_datum = (u32)rng->priv;
+
 	return via_rng_datum;
 }
 
-static int __init via_init(struct pci_dev *dev)
+static int __init via_init(struct hwrng *rng)
 {
 	u32 lo, hi, old_lo;
 
@@ -472,7 +488,7 @@
 	return 0;
 }
 
-static void via_cleanup(void)
+static void via_cleanup(struct hwrng *rng)
 {
 	/* do nothing */
 }
@@ -484,13 +500,12 @@
  *
  */
 
-static void __iomem *geode_rng_base = NULL;
-
 #define GEODE_RNG_DATA_REG   0x50
 #define GEODE_RNG_STATUS_REG 0x54
 
-static u32 geode_data_read(void)
+static u32 geode_data_read(struct hwrng *rng)
 {
+	void __iomem *geode_rng_base = (void __iomem *)rng->priv;
 	u32 val;
 
 	assert(geode_rng_base != NULL);
@@ -498,8 +513,9 @@
 	return val;
 }
 
-static unsigned int geode_data_present(void)
+static unsigned int geode_data_present(struct hwrng *rng)
 {
+	void __iomem *geode_rng_base = (void __iomem *)rng->priv;
 	u32 val;
 
 	assert(geode_rng_base != NULL);
@@ -507,14 +523,18 @@
 	return val;
 }
 
-static void geode_cleanup(void)
+static void geode_cleanup(struct hwrng *rng)
 {
+	void __iomem *geode_rng_base = (void __iomem *)rng->priv;
+
 	iounmap(geode_rng_base);
   	geode_rng_base = NULL;
 }
 
-static int geode_init(struct pci_dev *dev)
+static int geode_init(struct hwrng *rng)
 {
+	void __iomem *geode_rng_base;
+	struct pci_dev *dev = rng->dev;
 	unsigned long rng_base = pci_resource_start(dev, 0);
 
 	if (rng_base == 0)
@@ -526,6 +546,7 @@
 		printk(KERN_ERR PFX "Cannot ioremap RNG memory\n");
 		return -EBUSY;
 	}
+	rng->priv = (unsigned long)geode_rng_base;
 
 	return 0;
 }
@@ -543,7 +564,6 @@
 		return -EINVAL;
 	if (filp->f_mode & FMODE_WRITE)
 		return -EINVAL;
-
 	return 0;
 }
 
@@ -551,21 +571,26 @@
 static ssize_t rng_dev_read (struct file *filp, char __user *buf, size_t size,
 				loff_t * offp)
 {
-	static DEFINE_SPINLOCK(rng_lock);
 	unsigned int have_data;
 	u32 data = 0;
 	ssize_t ret = 0;
+	int err;
 
 	while (size) {
-		spin_lock(&rng_lock);
-
+		err = mutex_lock_interruptible(&rng_mutex);
+		if (err)
+			return err;
+		if (!current_rng) {
+			mutex_unlock(&rng_mutex);
+			return -ENODEV;
+		}
 		have_data = 0;
-		if (rng_ops->data_present()) {
-			data = rng_ops->data_read();
-			have_data = rng_ops->n_bytes;
+		if (current_rng->data_present == NULL ||
+		    current_rng->data_present(current_rng)) {
+			data = current_rng->data_read(current_rng);
+			have_data = current_rng->n_bytes;
 		}
-
-		spin_unlock (&rng_lock);
+		mutex_unlock(&rng_mutex);
 
 		while (have_data && size) {
 			if (put_user((u8)data, buf++)) {
@@ -593,38 +618,186 @@
 }
 
 
+static ssize_t hwrng_attr_current_store(struct class_device *class,
+					const char *buf, size_t len)
+{
+	int err = -ENODEV;
+	struct hwrng *rng;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	err = mutex_lock_interruptible(&rng_mutex);
+	if (err)
+		return err;
+	err = -ENODEV;
+	list_for_each_entry(rng, &rng_list, list) {
+		if (strncmp(rng->name, buf, len) == 0) {
+			if (rng->init) {
+				err = rng->init(rng);
+				if (err)
+					break;
+			}
+			if (current_rng && current_rng->cleanup)
+				current_rng->cleanup(current_rng);
+			current_rng = rng;
+			err = 0;
+			break;
+		}
+	}
+	mutex_unlock(&rng_mutex);
 
-/*
- * rng_init_one - look for and attempt to init a single RNG
- */
-static int __init rng_init_one (struct pci_dev *dev)
+	return err ? err : len;
+}
+
+static ssize_t hwrng_attr_current_show(struct class_device *class,
+				       char *buf)
 {
-	int rc;
+	int err;
+	ssize_t ret;
+	const char *name;
 
-	DPRINTK ("ENTER\n");
+	err = mutex_lock_interruptible(&rng_mutex);
+	if (err)
+		return err;
+	if (current_rng)
+		name = current_rng->name;
+	else
+		name = "none";
+	ret = sprintf(buf, "%s\n", name);
+	mutex_unlock(&rng_mutex);
 
-	assert(rng_ops != NULL);
+	return ret;
+}
 
-	rc = rng_ops->init(dev);
-	if (rc)
-		goto err_out;
+static ssize_t hwrng_attr_available_show(struct class_device *class,
+					 char *buf)
+{
+	int err;
+	ssize_t ret = 0;
+	struct hwrng *rng;
 
-	rc = misc_register (&rng_miscdev);
-	if (rc) {
-		printk (KERN_ERR PFX "misc device register failed\n");
-		goto err_out_cleanup_hw;
+	err = mutex_lock_interruptible(&rng_mutex);
+	if (err)
+		return err;
+	buf[0] = '\0';
+	list_for_each_entry(rng, &rng_list, list) {
+		ret += strlen(rng->name);
+		strcat(buf, rng->name);
+		ret += 1;
+		strcat(buf, " ");
 	}
+	strcat(buf, "\n");
+	ret += 1;
+	mutex_unlock(&rng_mutex);
 
-	DPRINTK ("EXIT, returning 0\n");
-	return 0;
+	return ret;
+}
 
-err_out_cleanup_hw:
-	rng_ops->cleanup();
-err_out:
-	DPRINTK ("EXIT, returning %d\n", rc);
-	return rc;
+static CLASS_DEVICE_ATTR(rng_current, S_IRUGO | S_IWUSR,
+			 hwrng_attr_current_show,
+			 hwrng_attr_current_store);
+static CLASS_DEVICE_ATTR(rng_available, S_IRUGO,
+			 hwrng_attr_available_show,
+			 NULL);
+
+
+static void unregister_miscdev(void)
+{
+	class_device_remove_file(rng_miscdev.class,
+				 &class_device_attr_rng_available);
+	class_device_remove_file(rng_miscdev.class,
+				 &class_device_attr_rng_current);
+	misc_deregister(&rng_miscdev);
+}
+
+static int register_miscdev(void)
+{
+	int err;
+
+	err = misc_register(&rng_miscdev);
+	if (err)
+		goto out;
+	err = class_device_create_file(rng_miscdev.class,
+				       &class_device_attr_rng_current);
+	if (err)
+		goto err_misc_dereg;
+	err = class_device_create_file(rng_miscdev.class,
+				       &class_device_attr_rng_available);
+	if (err)
+		goto err_remove_current;
+out:
+	return err;
+
+err_remove_current:
+	class_device_remove_file(rng_miscdev.class,
+				 &class_device_attr_rng_current);
+err_misc_dereg:
+	misc_deregister(&rng_miscdev);
+	goto out;
+}
+
+int hwrng_register(struct hwrng *rng)
+{
+	int must_register_misc;
+	int err;
+	struct hwrng *old_current;
+
+	if (rng->name == NULL)
+		return -EINVAL;
+	if (rng->data_read == NULL)
+		return -EINVAL;
+	if (rng->n_bytes < 1 || rng->n_bytes > sizeof(u32))
+		return -EINVAL;
+
+	mutex_lock(&rng_mutex);
+	must_register_misc = (current_rng == NULL);
+	old_current = current_rng;
+	if (!current_rng) {
+		if (rng->init) {
+			err = rng->init(rng);
+			if (err) {
+				mutex_unlock(&rng_mutex);
+				return err;
+			}
+		}
+		current_rng = rng;
+	}
+	INIT_LIST_HEAD(&rng->list);
+	list_add_tail(&rng->list, &rng_list);
+	err = 0;
+	if (must_register_misc) {
+		err = register_miscdev();
+		if (err) {
+			if (rng->cleanup)
+				rng->cleanup(rng);
+			list_del(&rng->list);
+			current_rng = old_current;
+		}
+	}
+
+	mutex_unlock(&rng_mutex);
+
+	return err;
 }
+EXPORT_SYMBOL_GPL(hwrng_register);
 
+void hwrng_unregister(struct hwrng *rng)
+{
+	mutex_lock(&rng_mutex);
+	list_del(&rng->list);
+	if (current_rng == rng) {
+		if (rng->cleanup)
+			rng->cleanup(rng);
+		if (list_empty(&rng_list))
+			current_rng = NULL;
+		else
+			current_rng = list_entry(rng_list.prev, struct hwrng, list);
+	}
+	if (list_empty(&rng_list))
+		unregister_miscdev();
+	mutex_unlock(&rng_mutex);
+}
+EXPORT_SYMBOL_GPL(hwrng_unregister);
 
 
 MODULE_AUTHOR("The Linux Kernel team");
@@ -637,7 +810,7 @@
  */
 static int __init rng_init (void)
 {
-	int rc;
+	int err;
 	struct pci_dev *pdev = NULL;
 	const struct pci_device_id *ent;
 
@@ -647,28 +820,30 @@
 	for_each_pci_dev(pdev) {
 		ent = pci_match_id(rng_pci_tbl, pdev);
 		if (ent) {
-			rng_ops = &rng_vendor_ops[ent->driver_data];
-			goto match;
+			err = hwrng_register(&rng_vendor_ops[ent->driver_data]);
+			if (err) {
+				printk(KERN_ERR PFX "Could not register Intel, "
+						    "AMD or Geode RNG\n");
+				return err;
+			}
+			goto out;
 		}
 	}
 
 #ifdef __i386__
 	/* Probe for VIA RNG */
 	if (cpu_has_xstore) {
-		rng_ops = &rng_vendor_ops[rng_hw_via];
-		pdev = NULL;
-		goto match;
+		err = hwrng_register(&rng_vendor_ops[rng_hw_via]);
+		if (err) {
+			printk(KERN_ERR PFX "Could not register VIA RNG\n");
+			return err;
+		}
+		goto out;
 	}
 #endif
 
-	DPRINTK ("EXIT, returning -ENODEV\n");
-	return -ENODEV;
-
-match:
-	rc = rng_init_one (pdev);
-	if (rc)
-		return rc;
-
+	DPRINTK ("no device found\n");
+out:
 	pr_info( RNG_DRIVER_NAME " loaded\n");
 
 	DPRINTK ("EXIT, returning 0\n");
@@ -683,10 +858,8 @@
 {
 	DPRINTK ("ENTER\n");
 
-	misc_deregister (&rng_miscdev);
-
-	if (rng_ops->cleanup)
-		rng_ops->cleanup();
+	if (current_rng)
+		hwrng_unregister(current_rng);
 
 	DPRINTK ("EXIT\n");
 }
diff -urNX 2.6.16-rc4-mm2/Documentation/dontdiff 2.6.16-rc4-mm2.orig/drivers/char/Kconfig 2.6.16-rc4-mm2/drivers/char/Kconfig
--- 2.6.16-rc4-mm2.orig/drivers/char/Kconfig	2006-02-28 11:54:48.000000000 +0100
+++ 2.6.16-rc4-mm2/drivers/char/Kconfig	2006-02-28 11:55:34.000000000 +0100
@@ -653,8 +653,8 @@
 	  If you're not sure, say N.
 
 config HW_RANDOM
-	tristate "Intel/AMD/VIA HW Random Number Generator support"
-	depends on (X86 || IA64) && PCI
+	tristate "Intel/AMD/VIA/Generic HW Random Number Generator support"
+	depends on PCI
 	---help---
 	  This driver provides kernel-side support for the Random Number
 	  Generator hardware found on Intel i8xx-based motherboards,
diff -urNX 2.6.16-rc4-mm2/Documentation/dontdiff 2.6.16-rc4-mm2.orig/include/linux/hw_random.h 2.6.16-rc4-mm2/include/linux/hw_random.h
--- 2.6.16-rc4-mm2.orig/include/linux/hw_random.h	1970-01-01 01:00:00.000000000 +0100
+++ 2.6.16-rc4-mm2/include/linux/hw_random.h	2006-02-28 11:55:34.000000000 +0100
@@ -0,0 +1,48 @@
+/*
+	Hardware Random Number Generator
+
+	Please read Documentation/hw_random.txt for details on use.
+
+	----------------------------------------------------------
+	This software may be used and distributed according to the terms
+        of the GNU General Public License, incorporated herein by reference.
+
+ */
+
+#ifndef LINUX_HWRANDOM_H_
+#define LINUX_HWRANDOM_H_
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+struct pci_dev;
+
+struct hwrng {
+	/** Unique name. */
+	const char *name;
+	/** Pointer to the PCI device (can be NULL). */
+	struct pci_dev *dev;
+
+	/** Initialization callback. */
+	int (*init) (struct hwrng *rng);
+	/** Cleanup callback. */
+	void (*cleanup) (struct hwrng *rng);
+	/** Is the RNG able to provide data now? */
+	unsigned int (*data_present) (struct hwrng *rng);
+	/** Read data from the RNG device. */
+	u32 (*data_read) (struct hwrng *rng);
+	/** Number of bytes read per data_read() call.
+	  * This must be > 0 and < sizeof(u32).
+	  */
+	unsigned int n_bytes;
+	/** Private data, for use by the RNG driver. */
+	unsigned long priv;
+
+	/* internal. */
+	struct list_head list;
+};
+
+extern int hwrng_register(struct hwrng *rng);
+extern void hwrng_unregister(struct hwrng *rng);
+
+#endif /* LINUX_HWRANDOM_H_ */

-- 
Greetings Michael.

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