[patch 0/6] New Generic HW RNG (#2)

[patch 0/6] New Generic HW RNG (#2)

[Michael Buesch]

Second try. Various fixes included. This does even compile (and work) now. :)

This patch series replaces the old non-generic Hardware Random Number Generator support by a fully generic RNG API.

This makes it possible to register additional RNGs from modules. With this patch series applied, Laptops with
a bcm43xx chip (PowerBook) have a HW RNG available now.

Additionally two new RNG drivers are added for the "ixp4xx" and "omap" devices. (Written by Deepak Saxena).
This patch series includes the old patches by Deepak Saxena.

The x86-rng driver is the old RNG driver ported to the new API (and cleaned up a bit).

The userspace RNG daemon can later be updated to select the RNG through /sys/class/misc/hw_random/ for convenience. For now it is sufficient to use cat and echo -n on the sysfs attributes.

Please apply to -mm for testing.

[patch 1/6] New Generic HW RNG (#2)

[Michael Buesch]

[-- Attachment #1: remove-old-hw-random.patch --]
[-- Type: text/plain, Size: 17923 bytes --]

Remove the old H/W RNG support.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Index: hwrng/drivers/char/Kconfig
===================================================================
--- hwrng.orig/drivers/char/Kconfig	2006-05-07 01:29:34.000000000 +0200
+++ hwrng/drivers/char/Kconfig	2006-05-07 01:35:45.000000000 +0200
@@ -670,21 +670,6 @@
 
 	  If you're not sure, say N.
 
-config HW_RANDOM
-	tristate "Intel/AMD/VIA HW Random Number Generator support"
-	depends on (X86 || IA64) && PCI
-	---help---
-	  This driver provides kernel-side support for the Random Number
-	  Generator hardware found on Intel i8xx-based motherboards,
-	  AMD 76x-based motherboards, and Via Nehemiah CPUs.
-
-	  Provides a character driver, used to read() entropy data.
-
-	  To compile this driver as a module, choose M here: the
-	  module will be called hw_random.
-
-	  If unsure, say N.
-
 config NVRAM
 	tristate "/dev/nvram support"
 	depends on ATARI || X86 || ARM || GENERIC_NVRAM
Index: hwrng/drivers/char/Makefile
===================================================================
--- hwrng.orig/drivers/char/Makefile	2006-05-07 01:29:38.000000000 +0200
+++ hwrng/drivers/char/Makefile	2006-05-07 01:35:45.000000000 +0200
@@ -75,7 +75,6 @@
 obj-$(CONFIG_TOSHIBA)		+= toshiba.o
 obj-$(CONFIG_I8K)		+= i8k.o
 obj-$(CONFIG_DS1620)		+= ds1620.o
-obj-$(CONFIG_HW_RANDOM)		+= hw_random.o
 obj-$(CONFIG_FTAPE)		+= ftape/
 obj-$(CONFIG_COBALT_LCD)	+= lcd.o
 obj-$(CONFIG_PPDEV)		+= ppdev.o
Index: hwrng/drivers/char/hw_random.c
===================================================================
--- hwrng.orig/drivers/char/hw_random.c	2006-05-07 01:24:23.000000000 +0200
+++ /dev/null	1970-01-01 00:00:00.000000000 +0000
@@ -1,698 +0,0 @@
-/*
-        Added support for the AMD Geode LX RNG
-	(c) Copyright 2004-2005 Advanced Micro Devices, Inc.
-
-	derived from
-
- 	Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
-	(c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
- 
- 	derived from
- 
-        Hardware driver for the AMD 768 Random Number Generator (RNG)
-        (c) Copyright 2001 Red Hat Inc <alan@redhat.com>
-
- 	derived from
- 
-	Hardware driver for Intel i810 Random Number Generator (RNG)
-	Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
-	Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
-
-	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.
-
- */
-
-
-#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>
-#include <linux/miscdevice.h>
-#include <linux/smp_lock.h>
-#include <linux/mm.h>
-#include <linux/delay.h>
-
-#ifdef __i386__
-#include <asm/msr.h>
-#include <asm/cpufeature.h>
-#endif
-
-#include <asm/io.h>
-#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 ": "
-
-
-/*
- * debugging macros
- */
-
-/* pr_debug() collapses to a no-op if DEBUG is not defined */
-#define DPRINTK(fmt, args...) pr_debug(PFX "%s: " fmt, __FUNCTION__ , ## args)
-
-
-#undef RNG_NDEBUG        /* define to enable lightweight runtime checks */
-#ifdef RNG_NDEBUG
-#define assert(expr)							\
-		if(!(expr)) {						\
-		printk(KERN_DEBUG PFX "Assertion failed! %s,%s,%s,"	\
-		"line=%d\n", #expr, __FILE__, __FUNCTION__, __LINE__);	\
-		}
-#else
-#define assert(expr)
-#endif
-
-#define RNG_MISCDEV_MINOR		183 /* official */
-
-static int rng_dev_open (struct inode *inode, struct file *filp);
-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);
-
-#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);
-#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 struct file_operations rng_chrdev_ops = {
-	.owner		= THIS_MODULE,
-	.open		= rng_dev_open,
-	.read		= rng_dev_read,
-};
-
-
-static struct miscdevice rng_miscdev = {
-	RNG_MISCDEV_MINOR,
-	RNG_MODULE_NAME,
-	&rng_chrdev_ops,
-};
-
-enum {
-	rng_hw_none,
-	rng_hw_intel,
-	rng_hw_amd,
-#ifdef __i386__
-	rng_hw_via,
-#endif
-	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 },
-
-#ifdef __i386__
-	/* rng_hw_via */
-	{ via_init, via_cleanup, via_data_present, via_data_read, 1 },
-#endif
-
-	/* rng_hw_geode */
-	{ geode_init, geode_cleanup, geode_data_present, geode_data_read, 4 }
-};
-
-/*
- * Data for PCI driver interface
- *
- * This data only exists for exporting the supported
- * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
- * register a pci_driver, because someone else might one day
- * want to register another driver on the same PCI id.
- */
-static struct pci_device_id rng_pci_tbl[] = {
-	{ 0x1022, 0x7443, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_amd },
-	{ 0x1022, 0x746b, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_amd },
-
-	{ 0x8086, 0x2418, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
-	{ 0x8086, 0x2428, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
-	{ 0x8086, 0x2430, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
-	{ 0x8086, 0x2448, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
-	{ 0x8086, 0x244e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
-	{ 0x8086, 0x245e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
-
-	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES,
-	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_geode },
-
-	{ 0, },	/* terminate list */
-};
-MODULE_DEVICE_TABLE (pci, rng_pci_tbl);
-
-
-/***********************************************************************
- *
- * Intel RNG operations
- *
- */
-
-/*
- * RNG registers (offsets from rng_mem)
- */
-#define INTEL_RNG_HW_STATUS			0
-#define         INTEL_RNG_PRESENT		0x40
-#define         INTEL_RNG_ENABLED		0x01
-#define INTEL_RNG_STATUS			1
-#define         INTEL_RNG_DATA_PRESENT		0x01
-#define INTEL_RNG_DATA				2
-
-/*
- * Magic address at which Intel PCI bridges locate the RNG
- */
-#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)
-{
-	assert (rng_mem != NULL);
-	return readb (rng_mem + INTEL_RNG_HW_STATUS);
-}
-
-static inline u8 intel_hwstatus_set (u8 hw_status)
-{
-	assert (rng_mem != NULL);
-	writeb (hw_status, rng_mem + INTEL_RNG_HW_STATUS);
-	return intel_hwstatus ();
-}
-
-static unsigned int intel_data_present(void)
-{
-	assert (rng_mem != NULL);
-
-	return (readb (rng_mem + INTEL_RNG_STATUS) & INTEL_RNG_DATA_PRESENT) ?
-		1 : 0;
-}
-
-static u32 intel_data_read(void)
-{
-	assert (rng_mem != NULL);
-
-	return readb (rng_mem + INTEL_RNG_DATA);
-}
-
-static int __init intel_init (struct pci_dev *dev)
-{
-	int rc;
-	u8 hw_status;
-
-	DPRINTK ("ENTER\n");
-
-	rng_mem = ioremap (INTEL_RNG_ADDR, INTEL_RNG_ADDR_LEN);
-	if (rng_mem == NULL) {
-		printk (KERN_ERR PFX "cannot ioremap RNG Memory\n");
-		rc = -EBUSY;
-		goto err_out;
-	}
-
-	/* Check for Intel 82802 */
-	hw_status = intel_hwstatus ();
-	if ((hw_status & INTEL_RNG_PRESENT) == 0) {
-		printk (KERN_ERR PFX "RNG not detected\n");
-		rc = -ENODEV;
-		goto err_out_free_map;
-	}
-
-	/* 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);
-	if ((hw_status & INTEL_RNG_ENABLED) == 0) {
-		printk (KERN_ERR PFX "cannot enable RNG, aborting\n");
-		rc = -EIO;
-		goto err_out_free_map;
-	}
-
-	DPRINTK ("EXIT, returning 0\n");
-	return 0;
-
-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)
-{
-	u8 hw_status;
-
-	hw_status = intel_hwstatus ();
-	if (hw_status & INTEL_RNG_ENABLED)
-		intel_hwstatus_set (hw_status & ~INTEL_RNG_ENABLED);
-	else
-		printk(KERN_WARNING PFX "unusual: RNG already disabled\n");
-	iounmap(rng_mem);
-	rng_mem = NULL;
-}
-
-/***********************************************************************
- *
- * AMD RNG operations
- *
- */
-
-static u32 pmbase;			/* PMxx I/O base */
-static struct pci_dev *amd_dev;
-
-static unsigned int amd_data_present (void)
-{
-      	return inl(pmbase + 0xF4) & 1;
-}
-
-
-static u32 amd_data_read (void)
-{
-	return inl(pmbase + 0xF0);
-}
-
-static int __init amd_init (struct pci_dev *dev)
-{
-	int rc;
-	u8 rnen;
-
-	DPRINTK ("ENTER\n");
-
-	pci_read_config_dword(dev, 0x58, &pmbase);
-
-	pmbase &= 0x0000FF00;
-
-	if (pmbase == 0)
-	{
-		printk (KERN_ERR PFX "power management base not set\n");
-		rc = -EIO;
-		goto err_out;
-	}
-
-	pci_read_config_byte(dev, 0x40, &rnen);
-	rnen |= (1 << 7);	/* RNG on */
-	pci_write_config_byte(dev, 0x40, rnen);
-
-	pci_read_config_byte(dev, 0x41, &rnen);
-	rnen |= (1 << 7);	/* PMIO enable */
-	pci_write_config_byte(dev, 0x41, rnen);
-
-	pr_info( PFX "AMD768 system management I/O registers at 0x%X.\n",
-			pmbase);
-
-	amd_dev = dev;
-
-	DPRINTK ("EXIT, returning 0\n");
-	return 0;
-
-err_out:
-	DPRINTK ("EXIT, returning %d\n", rc);
-	return rc;
-}
-
-static void amd_cleanup(void)
-{
-	u8 rnen;
-
-	pci_read_config_byte(amd_dev, 0x40, &rnen);
-	rnen &= ~(1 << 7);	/* RNG off */
-	pci_write_config_byte(amd_dev, 0x40, rnen);
-
-	/* FIXME: twiddle pmio, also? */
-}
-
-#ifdef __i386__
-/***********************************************************************
- *
- * VIA RNG operations
- *
- */
-
-enum {
-	VIA_STRFILT_CNT_SHIFT	= 16,
-	VIA_STRFILT_FAIL	= (1 << 15),
-	VIA_STRFILT_ENABLE	= (1 << 14),
-	VIA_RAWBITS_ENABLE	= (1 << 13),
-	VIA_RNG_ENABLE		= (1 << 6),
-	VIA_XSTORE_CNT_MASK	= 0x0F,
-
-	VIA_RNG_CHUNK_8		= 0x00,	/* 64 rand bits, 64 stored bits */
-	VIA_RNG_CHUNK_4		= 0x01,	/* 32 rand bits, 32 stored bits */
-	VIA_RNG_CHUNK_4_MASK	= 0xFFFFFFFF,
-	VIA_RNG_CHUNK_2		= 0x02,	/* 16 rand bits, 32 stored bits */
-	VIA_RNG_CHUNK_2_MASK	= 0xFFFF,
-	VIA_RNG_CHUNK_1		= 0x03,	/* 8 rand bits, 32 stored bits */
-	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
- * downside is that the instruction becomes no longer atomic.  Due to
- * this, just like familiar issues with /dev/random itself, the worst
- * case of a 'rep xstore' could potentially pause a cpu for an
- * unreasonably long time.  In practice, this condition would likely
- * only occur when the hardware is failing.  (or so we hope :))
- *
- * Another possible performance boost may come from simply buffering
- * until we have 4 bytes, thus returning a u32 at a time,
- * instead of the current u8-at-a-time.
- */
-
-static inline u32 xstore(u32 *addr, u32 edx_in)
-{
-	u32 eax_out;
-
-	asm(".byte 0x0F,0xA7,0xC0 /* xstore %%edi (addr=%0) */"
-		:"=m"(*addr), "=a"(eax_out)
-		:"D"(addr), "d"(edx_in));
-
-	return eax_out;
-}
-
-static unsigned int via_data_present(void)
-{
-	u32 bytes_out;
-
-	/* We choose the recommended 1-byte-per-instruction RNG rate,
-	 * for greater randomness at the expense of speed.  Larger
-	 * values 2, 4, or 8 bytes-per-instruction yield greater
-	 * speed at lesser randomness.
-	 *
-	 * If you change this to another VIA_CHUNK_n, you must also
-	 * change the ->n_bytes values in rng_vendor_ops[] tables.
-	 * VIA_CHUNK_8 requires further code changes.
-	 *
-	 * 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;
-	if (bytes_out == 0)
-		return 0;
-
-	return 1;
-}
-
-static u32 via_data_read(void)
-{
-	return via_rng_datum;
-}
-
-static int __init via_init(struct pci_dev *dev)
-{
-	u32 lo, hi, old_lo;
-
-	/* Control the RNG via MSR.  Tread lightly and pay very close
-	 * close attention to values written, as the reserved fields
-	 * are documented to be "undefined and unpredictable"; but it
-	 * does not say to write them as zero, so I make a guess that
-	 * we restore the values we find in the register.
-	 */
-	rdmsr(MSR_VIA_RNG, lo, hi);
-
-	old_lo = lo;
-	lo &= ~(0x7f << VIA_STRFILT_CNT_SHIFT);
-	lo &= ~VIA_XSTORE_CNT_MASK;
-	lo &= ~(VIA_STRFILT_ENABLE | VIA_STRFILT_FAIL | VIA_RAWBITS_ENABLE);
-	lo |= VIA_RNG_ENABLE;
-
-	if (lo != old_lo)
-		wrmsr(MSR_VIA_RNG, lo, hi);
-
-	/* perhaps-unnecessary sanity check; remove after testing if
-	   unneeded */
-	rdmsr(MSR_VIA_RNG, lo, hi);
-	if ((lo & VIA_RNG_ENABLE) == 0) {
-		printk(KERN_ERR PFX "cannot enable VIA C3 RNG, aborting\n");
-		return -ENODEV;
-	}
-
-	return 0;
-}
-
-static void via_cleanup(void)
-{
-	/* do nothing */
-}
-#endif
-
-/***********************************************************************
- *
- * AMD Geode RNG operations
- *
- */
-
-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)
-{
-	u32 val;
-
-	assert(geode_rng_base != NULL);
-	val = readl(geode_rng_base + GEODE_RNG_DATA_REG);
-	return val;
-}
-
-static unsigned int geode_data_present(void)
-{
-	u32 val;
-
-	assert(geode_rng_base != NULL);
-	val = readl(geode_rng_base + GEODE_RNG_STATUS_REG);
-	return val;
-}
-
-static void geode_cleanup(void)
-{
-	iounmap(geode_rng_base);
-  	geode_rng_base = NULL;
-}
-
-static int geode_init(struct pci_dev *dev)
-{
-	unsigned long rng_base = pci_resource_start(dev, 0);
-
-	if (rng_base == 0)
-		return 1;
-
-	geode_rng_base = ioremap(rng_base, 0x58);
-
-	if (geode_rng_base == NULL) {
-		printk(KERN_ERR PFX "Cannot ioremap RNG memory\n");
-		return -EBUSY;
-	}
-
-	return 0;
-}
-
-/***********************************************************************
- *
- * /dev/hwrandom character device handling (major 10, minor 183)
- *
- */
-
-static int rng_dev_open (struct inode *inode, struct file *filp)
-{
-	/* enforce read-only access to this chrdev */
-	if ((filp->f_mode & FMODE_READ) == 0)
-		return -EINVAL;
-	if (filp->f_mode & FMODE_WRITE)
-		return -EINVAL;
-
-	return 0;
-}
-
-
-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;
-
-	while (size) {
-		spin_lock(&rng_lock);
-
-		have_data = 0;
-		if (rng_ops->data_present()) {
-			data = rng_ops->data_read();
-			have_data = rng_ops->n_bytes;
-		}
-
-		spin_unlock (&rng_lock);
-
-		while (have_data && size) {
-			if (put_user((u8)data, buf++)) {
-				ret = ret ? : -EFAULT;
-				break;
-			}
-			size--;
-			ret++;
-			have_data--;
-			data>>=8;
-		}
-
-		if (filp->f_flags & O_NONBLOCK)
-			return ret ? : -EAGAIN;
-
-		if(need_resched())
-			schedule_timeout_interruptible(1);
-		else
-			udelay(200);	/* FIXME: We could poll for 250uS ?? */
-
-		if (signal_pending (current))
-			return ret ? : -ERESTARTSYS;
-	}
-	return ret;
-}
-
-
-
-/*
- * rng_init_one - look for and attempt to init a single RNG
- */
-static int __init rng_init_one (struct pci_dev *dev)
-{
-	int rc;
-
-	DPRINTK ("ENTER\n");
-
-	assert(rng_ops != NULL);
-
-	rc = rng_ops->init(dev);
-	if (rc)
-		goto err_out;
-
-	rc = misc_register (&rng_miscdev);
-	if (rc) {
-		printk (KERN_ERR PFX "misc device register failed\n");
-		goto err_out_cleanup_hw;
-	}
-
-	DPRINTK ("EXIT, returning 0\n");
-	return 0;
-
-err_out_cleanup_hw:
-	rng_ops->cleanup();
-err_out:
-	DPRINTK ("EXIT, returning %d\n", rc);
-	return rc;
-}
-
-
-
-MODULE_AUTHOR("The Linux Kernel team");
-MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver");
-MODULE_LICENSE("GPL");
-
-
-/*
- * rng_init - initialize RNG module
- */
-static int __init rng_init (void)
-{
-	int rc;
-	struct pci_dev *pdev = NULL;
-	const struct pci_device_id *ent;
-
-	DPRINTK ("ENTER\n");
-
-	/* Probe for Intel, AMD, Geode RNGs */
-	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;
-		}
-	}
-
-#ifdef __i386__
-	/* Probe for VIA RNG */
-	if (cpu_has_xstore) {
-		rng_ops = &rng_vendor_ops[rng_hw_via];
-		pdev = NULL;
-		goto match;
-	}
-#endif
-
-	DPRINTK ("EXIT, returning -ENODEV\n");
-	return -ENODEV;
-
-match:
-	rc = rng_init_one (pdev);
-	if (rc)
-		return rc;
-
-	pr_info( RNG_DRIVER_NAME " loaded\n");
-
-	DPRINTK ("EXIT, returning 0\n");
-	return 0;
-}
-
-
-/*
- * rng_init - shutdown RNG module
- */
-static void __exit rng_cleanup (void)
-{
-	DPRINTK ("ENTER\n");
-
-	misc_deregister (&rng_miscdev);
-
-	if (rng_ops->cleanup)
-		rng_ops->cleanup();
-
-	DPRINTK ("EXIT\n");
-}
-
-
-module_init (rng_init);
-module_exit (rng_cleanup);

--

[patch 2/6] New Generic HW RNG (#2)

[Michael Buesch]

[-- Attachment #1: add-hw-random-core.patch --]
[-- Type: text/plain, Size: 11544 bytes --]

Add a new generic H/W RNG core.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Index: hwrng/drivers/char/Kconfig
===================================================================
--- hwrng.orig/drivers/char/Kconfig	2006-05-07 01:53:30.000000000 +0200
+++ hwrng/drivers/char/Kconfig	2006-05-07 01:55:11.000000000 +0200
@@ -670,6 +670,8 @@
 
 	  If you're not sure, say N.
 
+source "drivers/char/hw_random/Kconfig"
+
 config NVRAM
 	tristate "/dev/nvram support"
 	depends on ATARI || X86 || ARM || GENERIC_NVRAM
Index: hwrng/drivers/char/Makefile
===================================================================
--- hwrng.orig/drivers/char/Makefile	2006-05-07 01:53:30.000000000 +0200
+++ hwrng/drivers/char/Makefile	2006-05-07 01:55:11.000000000 +0200
@@ -75,6 +75,7 @@
 obj-$(CONFIG_TOSHIBA)		+= toshiba.o
 obj-$(CONFIG_I8K)		+= i8k.o
 obj-$(CONFIG_DS1620)		+= ds1620.o
+obj-$(CONFIG_HW_RANDOM)		+= hw_random/
 obj-$(CONFIG_FTAPE)		+= ftape/
 obj-$(CONFIG_COBALT_LCD)	+= lcd.o
 obj-$(CONFIG_PPDEV)		+= ppdev.o
Index: hwrng/drivers/char/hw_random/Kconfig
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ hwrng/drivers/char/hw_random/Kconfig	2006-05-07 16:29:03.000000000 +0200
@@ -0,0 +1,11 @@
+#
+# Hardware Random Number Generator (RNG) configuration
+#
+
+config HW_RANDOM
+	bool "Hardware Random Number Generator Core support"
+	default y
+	---help---
+	  Hardware Random Number Generator Core infrastructure.
+
+	  If unsure, say Y.
Index: hwrng/drivers/char/hw_random/Makefile
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ hwrng/drivers/char/hw_random/Makefile	2006-05-07 16:29:03.000000000 +0200
@@ -0,0 +1,5 @@
+#
+# Makefile for HW Random Number Generator (RNG) device drivers.
+#
+
+obj-$(CONFIG_HW_RANDOM) += core.o
Index: hwrng/drivers/char/hw_random/core.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ hwrng/drivers/char/hw_random/core.c	2006-05-07 16:26:43.000000000 +0200
@@ -0,0 +1,337 @@
+/*
+        Added support for the AMD Geode LX RNG
+	(c) Copyright 2004-2005 Advanced Micro Devices, Inc.
+
+	derived from
+
+ 	Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
+	(c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
+
+ 	derived from
+
+        Hardware driver for the AMD 768 Random Number Generator (RNG)
+        (c) Copyright 2001 Red Hat Inc <alan@redhat.com>
+
+ 	derived from
+
+	Hardware driver for Intel i810 Random Number Generator (RNG)
+	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>
+	Copyright 2005 (c) MontaVista Software, Inc.
+
+	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.
+
+ */
+
+
+#include <linux/device.h>
+#include <linux/hw_random.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+#include <linux/delay.h>
+#include <asm/uaccess.h>
+
+
+#define RNG_MODULE_NAME		"hw_random"
+#define PFX RNG_MODULE_NAME	": "
+#define RNG_MISCDEV_MINOR		183 /* official */
+
+
+static struct hwrng *current_rng;
+static LIST_HEAD(rng_list);
+static DEFINE_MUTEX(rng_mutex);
+
+
+static int rng_dev_open(struct inode *inode, struct file *filp)
+{
+	/* enforce read-only access to this chrdev */
+	if ((filp->f_mode & FMODE_READ) == 0)
+		return -EINVAL;
+	if (filp->f_mode & FMODE_WRITE)
+		return -EINVAL;
+	return 0;
+}
+
+static ssize_t rng_dev_read(struct file *filp, char __user *buf,
+			    size_t size, loff_t *offp)
+{
+	unsigned int have_data;
+	u32 data = 0;
+	ssize_t ret = 0;
+	int i, err;
+
+	while (size) {
+		err = mutex_lock_interruptible(&rng_mutex);
+		if (err)
+			return ret ? : -ERESTARTSYS;
+		if (!current_rng) {
+			mutex_unlock(&rng_mutex);
+			return ret ? : -ENODEV;
+		}
+		have_data = 0;
+		if (current_rng->data_present == NULL ||
+		    current_rng->data_present(current_rng))
+			have_data = current_rng->data_read(current_rng, &data);
+		mutex_unlock(&rng_mutex);
+
+		while (have_data && size) {
+			if (put_user((u8)data, buf++)) {
+				ret = ret ? : -EFAULT;
+				break;
+			}
+			size--;
+			ret++;
+			have_data--;
+			data>>=8;
+		}
+
+		if (filp->f_flags & O_NONBLOCK)
+			return ret ? : -EAGAIN;
+
+		if (need_resched()) {
+			if (schedule_timeout_interruptible(1))
+				return ret ? : -ERESTARTSYS;
+		} else {
+			err = mutex_lock_interruptible(&rng_mutex);
+			if (err)
+				return ret ? : -ERESTARTSYS;
+			if (!current_rng) {
+				mutex_unlock(&rng_mutex);
+				return ret ? : -ENODEV;
+			}
+			for (i = 0; i < 20; i++) {
+				if (current_rng->data_present == NULL ||
+				    current_rng->data_present(current_rng))
+					break;
+				udelay(10);
+			}
+			mutex_unlock(&rng_mutex);
+		}
+
+		if (signal_pending(current))
+			return ret ? : -ERESTARTSYS;
+	}
+	return ret;
+}
+
+
+static struct file_operations rng_chrdev_ops = {
+	.owner		= THIS_MODULE,
+	.open		= rng_dev_open,
+	.read		= rng_dev_read,
+};
+
+static struct miscdevice rng_miscdev = {
+	.minor		= RNG_MISCDEV_MINOR,
+	.name		= RNG_MODULE_NAME,
+	.fops		= &rng_chrdev_ops,
+};
+
+
+static ssize_t hwrng_attr_current_store(struct class_device *class,
+					const char *buf, size_t len)
+{
+	int err;
+	struct hwrng *rng;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	err = mutex_lock_interruptible(&rng_mutex);
+	if (err)
+		return -ERESTARTSYS;
+	err = -ENODEV;
+	list_for_each_entry(rng, &rng_list, list) {
+		if (strcmp(rng->name, buf) == 0) {
+			if (rng == current_rng) {
+				err = 0;
+				break;
+			}
+			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);
+
+	return err ? : len;
+}
+
+static ssize_t hwrng_attr_current_show(struct class_device *class,
+				       char *buf)
+{
+	int err;
+	ssize_t ret;
+	const char *name = "none";
+
+	err = mutex_lock_interruptible(&rng_mutex);
+	if (err)
+		return -ERESTARTSYS;
+	if (current_rng)
+		name = current_rng->name;
+	ret = snprintf(buf, PAGE_SIZE, "%s\n", name);
+	mutex_unlock(&rng_mutex);
+
+	return ret;
+}
+
+static ssize_t hwrng_attr_available_show(struct class_device *class,
+					 char *buf)
+{
+	int err;
+	ssize_t ret = 0;
+	struct hwrng *rng;
+
+	err = mutex_lock_interruptible(&rng_mutex);
+	if (err)
+		return -ERESTARTSYS;
+	buf[0] = '\0';
+	list_for_each_entry(rng, &rng_list, list) {
+		strncat(buf, rng->name, PAGE_SIZE - ret - 1);
+		ret += strlen(rng->name);
+		strncat(buf, " ", PAGE_SIZE - ret - 1);
+		ret++;
+	}
+	strncat(buf, "\n", PAGE_SIZE - ret - 1);
+	ret++;
+	mutex_unlock(&rng_mutex);
+
+	return ret;
+}
+
+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_rng, *tmp;
+
+	if (rng->name == NULL)
+		return -EINVAL;
+	if (rng->data_read == NULL)
+		return -EINVAL;
+
+	mutex_lock(&rng_mutex);
+
+	/* Must not register two RNGs with the same name. */
+	list_for_each_entry(tmp, &rng_list, list) {
+		if (strcmp(tmp->name, rng->name) == 0)
+			return -EEXIST;
+	}
+
+	must_register_misc = (current_rng == NULL);
+	old_rng = current_rng;
+	if (!old_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) {
+			list_del(&rng->list);
+			if (!old_rng) {
+				if (rng->cleanup)
+					rng->cleanup(rng);
+				current_rng = NULL;
+			}
+		}
+	}
+
+	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");
+MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver");
+MODULE_LICENSE("GPL");
Index: hwrng/include/linux/hw_random.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ hwrng/include/linux/hw_random.h	2006-05-06 23:56:06.000000000 +0200
@@ -0,0 +1,50 @@
+/*
+	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_
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+/**
+ * struct hwrng - Hardware Random Number Generator driver
+ * @name:		Unique RNG name.
+ * @init:		Initialization callback (can be NULL).
+ * @cleanup:		Cleanup callback (can be NULL).
+ * @data_present:	Callback to determine if data is available
+ *			on the RNG. If NULL, it is assumed that
+ *			there is always data available.
+ * @data_read:		Read data from the RNG device.
+ *			Returns the number of lower random bytes in "data".
+ *			Must not be NULL.
+ * @priv:		Private data, for use by the RNG driver.
+ */
+struct hwrng {
+	const char *name;
+	int (*init)(struct hwrng *rng);
+	void (*cleanup)(struct hwrng *rng);
+	int (*data_present)(struct hwrng *rng);
+	int (*data_read)(struct hwrng *rng, u32 *data);
+	unsigned long priv;
+
+	/* internal. */
+	struct list_head list;
+};
+
+/** Register a new Hardware Random Number Generator driver. */
+extern int hwrng_register(struct hwrng *rng);
+/** Unregister a Hardware Random Number Generator driver. */
+extern void hwrng_unregister(struct hwrng *rng);
+
+#endif /* __KERNEL__ */
+#endif /* LINUX_HWRANDOM_H_ */

--

[patch 3/6] New Generic HW RNG (#2)

[Michael Buesch]

[-- Attachment #1: add-x86-hw-random.patch --]
[-- Type: text/plain, Size: 16298 bytes --]

Add a driver for the x86 RNG.
This driver is ported from the old hw_random.c

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Index: hwrng/drivers/char/hw_random/Kconfig
===================================================================
--- hwrng.orig/drivers/char/hw_random/Kconfig	2006-05-07 15:47:28.000000000 +0200
+++ hwrng/drivers/char/hw_random/Kconfig	2006-05-07 15:50:22.000000000 +0200
@@ -9,3 +9,16 @@
 	  Hardware Random Number Generator Core infrastructure.
 
 	  If unsure, say Y.
+
+config X86_RNG
+	tristate "Intel/AMD/VIA HW Random Number Generator support"
+	depends on HW_RANDOM && (X86 || IA64) && PCI
+	---help---
+	  This driver provides kernel-side support for the Random Number
+	  Generator hardware found on Intel i8xx-based motherboards,
+	  AMD 76x-based motherboards, and Via Nehemiah CPUs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called x86-rng.
+
+	  If unsure, say Y.
Index: hwrng/drivers/char/hw_random/Makefile
===================================================================
--- hwrng.orig/drivers/char/hw_random/Makefile	2006-05-07 15:47:28.000000000 +0200
+++ hwrng/drivers/char/hw_random/Makefile	2006-05-07 15:50:22.000000000 +0200
@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_HW_RANDOM) += core.o
+obj-$(CONFIG_X86_RNG) += x86-rng.o
Index: hwrng/drivers/char/hw_random/x86-rng.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ hwrng/drivers/char/hw_random/x86-rng.c	2006-05-07 15:50:22.000000000 +0200
@@ -0,0 +1,586 @@
+/*
+ * drivers/char/rng/x86.c
+ *
+ * RNG driver for Intel/AMD/VIA RNGs
+ *
+ * Copyright 2005 (c) MontaVista Software, Inc.
+ *
+ * with the majority of the code coming from:
+ *
+ * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
+ * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
+ *
+ * derived from
+ *
+ * Hardware driver for the AMD 768 Random Number Generator (RNG)
+ * (c) Copyright 2001 Red Hat Inc <alan@redhat.com>
+ *
+ * derived from
+ *
+ * Hardware driver for Intel i810 Random Number Generator (RNG)
+ * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
+ * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
+ *
+ * This file is licensed under  the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#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>
+#include <linux/miscdevice.h>
+#include <linux/smp_lock.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/hw_random.h>
+
+#include <asm/msr.h>
+#include <asm/cpufeature.h>
+
+#include <asm/io.h>
+
+
+/*
+ * debugging macros
+ */
+
+/* pr_debug() collapses to a no-op if DEBUG is not defined */
+#define DPRINTK(fmt, args...) pr_debug(PFX "%s: " fmt, __FUNCTION__ , ## args)
+
+#define RNG_VERSION "1.1.0"
+#define RNG_MODULE_NAME "x86-rng"
+#define RNG_DRIVER_NAME RNG_MODULE_NAME " hardware driver " RNG_VERSION
+#define PFX RNG_MODULE_NAME ": "
+
+#undef RNG_NDEBUG        /* define to enable lightweight runtime checks */
+#ifdef RNG_NDEBUG
+#define assert(expr)							\
+		if(!(expr)) {						\
+		printk(KERN_DEBUG PFX "Assertion failed! %s,%s,%s,"	\
+		"line=%d\n", #expr, __FILE__, __FUNCTION__, __LINE__);	\
+		}
+#else
+#define assert(expr)
+#endif
+
+static struct hwrng *x86_rng_ops;
+
+static int __init intel_init (struct hwrng *rng);
+static void intel_cleanup(struct hwrng *rng);
+static int intel_data_present (struct hwrng *rng);
+static int intel_data_read (struct hwrng *rng, u32 *data);
+
+static int __init amd_init (struct hwrng *rng);
+static void amd_cleanup(struct hwrng *rng);
+static int amd_data_present (struct hwrng *rng);
+static int amd_data_read (struct hwrng *rng, u32 *data);
+
+#ifdef __i386__
+static int __init via_init(struct hwrng *rng);
+static int via_data_present (struct hwrng *rng);
+static int via_data_read (struct hwrng *rng, u32 *data);
+#endif
+
+static int __init geode_init(struct hwrng *rng);
+static void geode_cleanup(struct hwrng *rng);
+static int geode_data_present (struct hwrng *rng);
+static int geode_data_read (struct hwrng *rng, u32 *data);
+
+enum {
+	rng_hw_none,
+	rng_hw_intel,
+	rng_hw_amd,
+#ifdef __i386__
+	rng_hw_via,
+#endif
+	rng_hw_geode,
+};
+
+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,
+	}, { /* rng_hw_amd */
+		.name		= "amd",
+		.init		= amd_init,
+		.cleanup	= amd_cleanup,
+		.data_present	= amd_data_present,
+		.data_read	= amd_data_read,
+	},
+#ifdef __i386__
+	{ /* rng_hw_via */
+		.name		= "via",
+		.init		= via_init,
+		.data_present	= via_data_present,
+		.data_read	= via_data_read,
+	},
+#endif
+	{ /* rng_hw_geode */
+		.name		= "geode",
+		.init		= geode_init,
+		.cleanup	= geode_cleanup,
+		.data_present	= geode_data_present,
+		.data_read	= geode_data_read,
+	},
+};
+
+/*
+ * Data for PCI driver interface
+ *
+ * This data only exists for exporting the supported
+ * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
+ * register a pci_driver, because someone else might one day
+ * want to register another driver on the same PCI id.
+ */
+static struct pci_device_id rng_pci_tbl[] = {
+	{ 0x1022, 0x7443, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_amd },
+	{ 0x1022, 0x746b, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_amd },
+
+	{ 0x8086, 0x2418, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
+	{ 0x8086, 0x2428, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
+	{ 0x8086, 0x2430, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
+	{ 0x8086, 0x2448, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
+	{ 0x8086, 0x244e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
+	{ 0x8086, 0x245e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
+
+	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES,
+	  PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_geode },
+
+	{ 0, },	/* terminate list */
+};
+MODULE_DEVICE_TABLE (pci, rng_pci_tbl);
+
+
+/***********************************************************************
+ *
+ * Intel RNG operations
+ *
+ */
+
+/*
+ * RNG registers (offsets from rng_mem)
+ */
+#define INTEL_RNG_HW_STATUS			0
+#define         INTEL_RNG_PRESENT		0x40
+#define         INTEL_RNG_ENABLED		0x01
+#define INTEL_RNG_STATUS			1
+#define         INTEL_RNG_DATA_PRESENT		0x01
+#define INTEL_RNG_DATA				2
+
+/*
+ * Magic address at which Intel PCI bridges locate the RNG
+ */
+#define INTEL_RNG_ADDR				0xFFBC015F
+#define INTEL_RNG_ADDR_LEN			3
+
+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 (void __iomem *rng_mem, u8 hw_status)
+{
+	assert (rng_mem != NULL);
+	writeb (hw_status, rng_mem + INTEL_RNG_HW_STATUS);
+	return intel_hwstatus (rng_mem);
+}
+
+static int intel_data_present(struct hwrng *rng)
+{
+	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 int intel_data_read(struct hwrng *rng, u32 *data)
+{
+	void __iomem *rng_mem = (void __iomem *)rng->priv;
+
+	assert (rng_mem != NULL);
+	*data = readb (rng_mem + INTEL_RNG_DATA);
+
+	return 1;
+}
+
+static int __init intel_init(struct hwrng *rng)
+{
+	void __iomem *rng_mem;
+	int rc;
+	u8 hw_status;
+
+	DPRINTK ("ENTER\n");
+
+	rng_mem = ioremap (INTEL_RNG_ADDR, INTEL_RNG_ADDR_LEN);
+	if (rng_mem == NULL) {
+		printk (KERN_ERR PFX "cannot ioremap RNG Memory\n");
+		rc = -EBUSY;
+		goto err_out;
+	}
+	rng->priv = (unsigned long)rng_mem;
+
+	/* Check for Intel 82802 */
+	hw_status = intel_hwstatus (rng_mem);
+	if ((hw_status & INTEL_RNG_PRESENT) == 0) {
+		printk (KERN_ERR PFX "RNG not detected\n");
+		rc = -ENODEV;
+		goto err_out_free_map;
+	}
+
+	/* turn RNG h/w on, if it's off */
+	if ((hw_status & INTEL_RNG_ENABLED) == 0)
+		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;
+		goto err_out_free_map;
+	}
+
+	DPRINTK ("EXIT, returning 0\n");
+	return 0;
+
+err_out_free_map:
+	iounmap (rng_mem);
+err_out:
+	DPRINTK ("EXIT, returning %d\n", rc);
+	return rc;
+}
+
+static void intel_cleanup(struct hwrng *rng)
+{
+	void __iomem *rng_mem = (void __iomem *)rng->priv;
+	u8 hw_status;
+
+	hw_status = intel_hwstatus (rng_mem);
+	if (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);
+}
+
+/***********************************************************************
+ *
+ * AMD RNG operations
+ *
+ */
+
+static struct pci_dev *amd_pdev;
+
+static int amd_data_present (struct hwrng *rng)
+{
+	u32 pmbase = (u32)rng->priv;
+
+      	return !!(inl(pmbase + 0xF4) & 1);
+}
+
+
+static int amd_data_read (struct hwrng *rng, u32 *data)
+{
+	u32 pmbase = (u32)rng->priv;
+
+	*data = inl(pmbase + 0xF0);
+
+	return 4;
+}
+
+static int __init amd_init(struct hwrng *rng)
+{
+	u32 pmbase;
+	int rc;
+	u8 rnen;
+
+	DPRINTK ("ENTER\n");
+
+	amd_pdev = (struct pci_dev *)rng->priv;
+	pci_read_config_dword(amd_pdev, 0x58, &pmbase);
+
+	pmbase &= 0x0000FF00;
+
+	if (pmbase == 0)
+	{
+		printk (KERN_ERR PFX "power management base not set\n");
+		rc = -EIO;
+		goto err_out;
+	}
+	rng->priv = (unsigned long)pmbase;
+
+	pci_read_config_byte(amd_pdev, 0x40, &rnen);
+	rnen |= (1 << 7);	/* RNG on */
+	pci_write_config_byte(amd_pdev, 0x40, rnen);
+
+	pci_read_config_byte(amd_pdev, 0x41, &rnen);
+	rnen |= (1 << 7);	/* PMIO enable */
+	pci_write_config_byte(amd_pdev, 0x41, rnen);
+
+	pr_info( PFX "AMD768 system management I/O registers at 0x%X.\n",
+			pmbase);
+
+	DPRINTK ("EXIT, returning 0\n");
+	return 0;
+
+err_out:
+	DPRINTK ("EXIT, returning %d\n", rc);
+	return rc;
+}
+
+static void amd_cleanup(struct hwrng *rng)
+{
+	u8 rnen;
+
+	pci_read_config_byte(amd_pdev, 0x40, &rnen);
+	rnen &= ~(1 << 7);	/* RNG off */
+	pci_write_config_byte(amd_pdev, 0x40, rnen);
+	amd_pdev = NULL;
+
+	/* FIXME: twiddle pmio, also? */
+}
+
+#ifdef __i386__
+/***********************************************************************
+ *
+ * VIA RNG operations
+ *
+ */
+
+enum {
+	VIA_STRFILT_CNT_SHIFT	= 16,
+	VIA_STRFILT_FAIL	= (1 << 15),
+	VIA_STRFILT_ENABLE	= (1 << 14),
+	VIA_RAWBITS_ENABLE	= (1 << 13),
+	VIA_RNG_ENABLE		= (1 << 6),
+	VIA_XSTORE_CNT_MASK	= 0x0F,
+
+	VIA_RNG_CHUNK_8		= 0x00,	/* 64 rand bits, 64 stored bits */
+	VIA_RNG_CHUNK_4		= 0x01,	/* 32 rand bits, 32 stored bits */
+	VIA_RNG_CHUNK_4_MASK	= 0xFFFFFFFF,
+	VIA_RNG_CHUNK_2		= 0x02,	/* 16 rand bits, 32 stored bits */
+	VIA_RNG_CHUNK_2_MASK	= 0xFFFF,
+	VIA_RNG_CHUNK_1		= 0x03,	/* 8 rand bits, 32 stored bits */
+	VIA_RNG_CHUNK_1_MASK	= 0xFF,
+};
+
+/*
+ * Investigate using the 'rep' prefix to obtain 32 bits of random data
+ * in one insn.  The upside is potentially better performance.  The
+ * downside is that the instruction becomes no longer atomic.  Due to
+ * this, just like familiar issues with /dev/random itself, the worst
+ * case of a 'rep xstore' could potentially pause a cpu for an
+ * unreasonably long time.  In practice, this condition would likely
+ * only occur when the hardware is failing.  (or so we hope :))
+ *
+ * Another possible performance boost may come from simply buffering
+ * until we have 4 bytes, thus returning a u32 at a time,
+ * instead of the current u8-at-a-time.
+ */
+
+static inline u32 xstore(u32 *addr, u32 edx_in)
+{
+	u32 eax_out;
+
+	asm(".byte 0x0F,0xA7,0xC0 /* xstore %%edi (addr=%0) */"
+		:"=m"(*addr), "=a"(eax_out)
+		:"D"(addr), "d"(edx_in));
+
+	return eax_out;
+}
+
+static 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
+	 * values 2, 4, or 8 bytes-per-instruction yield greater
+	 * speed at lesser randomness.
+	 *
+	 * If you change this to another VIA_CHUNK_n, you must also
+	 * change the ->n_bytes values in rng_vendor_ops[] tables.
+	 * VIA_CHUNK_8 requires further code changes.
+	 *
+	 * 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;
+	if (bytes_out == 0)
+		return 0;
+
+	return 1;
+}
+
+static int via_data_read(struct hwrng *rng, u32 *data)
+{
+	u32 via_rng_datum = (u32)rng->priv;
+
+	*data = via_rng_datum;
+
+	return 1;
+}
+
+static int __init via_init(struct hwrng *rng)
+{
+	u32 lo, hi, old_lo;
+
+	/* Control the RNG via MSR.  Tread lightly and pay very close
+	 * close attention to values written, as the reserved fields
+	 * are documented to be "undefined and unpredictable"; but it
+	 * does not say to write them as zero, so I make a guess that
+	 * we restore the values we find in the register.
+	 */
+	rdmsr(MSR_VIA_RNG, lo, hi);
+
+	old_lo = lo;
+	lo &= ~(0x7f << VIA_STRFILT_CNT_SHIFT);
+	lo &= ~VIA_XSTORE_CNT_MASK;
+	lo &= ~(VIA_STRFILT_ENABLE | VIA_STRFILT_FAIL | VIA_RAWBITS_ENABLE);
+	lo |= VIA_RNG_ENABLE;
+
+	if (lo != old_lo)
+		wrmsr(MSR_VIA_RNG, lo, hi);
+
+	/* perhaps-unnecessary sanity check; remove after testing if
+	   unneeded */
+	rdmsr(MSR_VIA_RNG, lo, hi);
+	if ((lo & VIA_RNG_ENABLE) == 0) {
+		printk(KERN_ERR PFX "cannot enable VIA C3 RNG, aborting\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+#endif
+
+/***********************************************************************
+ *
+ * AMD Geode RNG operations
+ *
+ */
+
+#define GEODE_RNG_DATA_REG   0x50
+#define GEODE_RNG_STATUS_REG 0x54
+
+static int geode_data_read(struct hwrng *rng, u32 *data)
+{
+	void __iomem *geode_rng_base = (void __iomem *)rng->priv;
+
+	assert(geode_rng_base != NULL);
+	*data = readl(geode_rng_base + GEODE_RNG_DATA_REG);
+
+	return 4;
+}
+
+static int geode_data_present(struct hwrng *rng)
+{
+	void __iomem *geode_rng_base = (void __iomem *)rng->priv;
+	u32 val;
+
+	assert(geode_rng_base != NULL);
+	val = readl(geode_rng_base + GEODE_RNG_STATUS_REG);
+
+	return !!val;
+}
+
+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 hwrng *rng)
+{
+	void __iomem *geode_rng_base;
+	struct pci_dev *dev = (struct pci_dev *)rng->priv;
+	unsigned long rng_base = pci_resource_start(dev, 0);
+
+	if (rng_base == 0)
+		return 1;
+
+	geode_rng_base = ioremap(rng_base, 0x58);
+
+	if (geode_rng_base == NULL) {
+		printk(KERN_ERR PFX "Cannot ioremap RNG memory\n");
+		return -EBUSY;
+	}
+	rng->priv = (unsigned long)geode_rng_base;
+
+	return 0;
+}
+
+
+/*
+ * rng_init - initialize RNG module
+ */
+static int __init x86_rng_init(void)
+{
+	int rc;
+	struct pci_dev *pdev = NULL;
+	const struct pci_device_id *ent;
+
+	DPRINTK ("ENTER\n");
+
+	/* Probe for Intel, AMD RNGs */
+	for_each_pci_dev(pdev) {
+		ent = pci_match_id(rng_pci_tbl, pdev);
+		if (ent) {
+			x86_rng_ops = &rng_vendor_ops[ent->driver_data];
+			goto match;
+		}
+	}
+
+	/* Probe for VIA RNG */
+	if (cpu_has_xstore) {
+		x86_rng_ops = &rng_vendor_ops[rng_hw_via];
+		pdev = NULL;
+		goto match;
+	}
+
+	DPRINTK ("EXIT, returning -ENODEV\n");
+	return -ENODEV;
+
+match:
+	x86_rng_ops->priv = (unsigned long)pdev;
+	rc = hwrng_register(x86_rng_ops);
+	if (rc)
+		return rc;
+
+	pr_info( RNG_DRIVER_NAME " loaded\n");
+
+	DPRINTK ("EXIT, returning 0\n");
+	return 0;
+}
+
+/*
+ * rng_init - shutdown RNG module
+ */
+static void __exit x86_rng_exit (void)
+{
+	DPRINTK ("ENTER\n");
+
+	hwrng_unregister(x86_rng_ops);
+
+	DPRINTK ("EXIT\n");
+}
+
+subsys_initcall(x86_rng_init);
+module_exit(x86_rng_exit);
+
+MODULE_AUTHOR("The Linux Kernel team");
+MODULE_DESCRIPTION("H/W RNG driver for Intel/AMD/VIA chipsets");
+MODULE_LICENSE("GPL");

--

Re: [patch 3/6] New Generic HW RNG (#2)

[Sergey Vlasov]

[-- Attachment #1: Type: text/plain, Size: 1846 bytes --]

On Sun, May 07, 2006 at 04:38:09PM +0200, Michael Buesch wrote:
> Add a driver for the x86 RNG.
> This driver is ported from the old hw_random.c
> 
[skip]
> +static int __init intel_init(struct hwrng *rng)

Cannot be __init anymore - now rng->init could be called at any time.

Also, there is another problem with putting this function into
rng->init - if another RNG has been registered when this module is
loaded, ->init will not be called during hwrng_register(), so the
module load will succeed even if the chipset does not have RNG
hardware.

> +{
> +	void __iomem *rng_mem;
> +	int rc;
> +	u8 hw_status;
> +
> +	DPRINTK ("ENTER\n");
> +
> +	rng_mem = ioremap (INTEL_RNG_ADDR, INTEL_RNG_ADDR_LEN);
> +	if (rng_mem == NULL) {
> +		printk (KERN_ERR PFX "cannot ioremap RNG Memory\n");
> +		rc = -EBUSY;
> +		goto err_out;
> +	}
> +	rng->priv = (unsigned long)rng_mem;
> +
> +	/* Check for Intel 82802 */
> +	hw_status = intel_hwstatus (rng_mem);
> +	if ((hw_status & INTEL_RNG_PRESENT) == 0) {
> +		printk (KERN_ERR PFX "RNG not detected\n");
> +		rc = -ENODEV;
> +		goto err_out_free_map;
> +	}
> +
> +	/* turn RNG h/w on, if it's off */
> +	if ((hw_status & INTEL_RNG_ENABLED) == 0)
> +		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;
> +		goto err_out_free_map;
> +	}
> +
> +	DPRINTK ("EXIT, returning 0\n");
> +	return 0;
> +
> +err_out_free_map:
> +	iounmap (rng_mem);
> +err_out:
> +	DPRINTK ("EXIT, returning %d\n", rc);
> +	return rc;
> +}
> +
[skip]
> +static int __init amd_init(struct hwrng *rng)

Again, __init is wrong.

[skip]
> +static int __init via_init(struct hwrng *rng)

This __init is wrong too.

[skip]

[-- Attachment #2: Type: application/pgp-signature, Size: 191 bytes --]

Re: [patch 3/6] New Generic HW RNG (#2)

[Michael Buesch]

On Sunday 07 May 2006 17:22, you wrote:
> On Sun, May 07, 2006 at 04:38:09PM +0200, Michael Buesch wrote:
> > Add a driver for the x86 RNG.
> > This driver is ported from the old hw_random.c
> > 
> [skip]
> > +static int __init intel_init(struct hwrng *rng)
> 
> Cannot be __init anymore - now rng->init could be called at any time.

Sure, will fix this.

> Also, there is another problem with putting this function into
> rng->init - if another RNG has been registered when this module is
> loaded, ->init will not be called during hwrng_register(), so the
> module load will succeed even if the chipset does not have RNG
> hardware.

Ok, I see. The question is, are we going to hwrng_register() the
intel, althought there is no device? We check for the PCI IDs.
Anyway. This should be fixed.
And I think this is also a good time to split the x86 driver,
so all this init-stuff is much cleaner.

> > +{
> > +	void __iomem *rng_mem;
> > +	int rc;
> > +	u8 hw_status;
> > +
> > +	DPRINTK ("ENTER\n");
> > +
> > +	rng_mem = ioremap (INTEL_RNG_ADDR, INTEL_RNG_ADDR_LEN);
> > +	if (rng_mem == NULL) {
> > +		printk (KERN_ERR PFX "cannot ioremap RNG Memory\n");
> > +		rc = -EBUSY;
> > +		goto err_out;
> > +	}
> > +	rng->priv = (unsigned long)rng_mem;
> > +
> > +	/* Check for Intel 82802 */
> > +	hw_status = intel_hwstatus (rng_mem);
> > +	if ((hw_status & INTEL_RNG_PRESENT) == 0) {
> > +		printk (KERN_ERR PFX "RNG not detected\n");
> > +		rc = -ENODEV;
> > +		goto err_out_free_map;
> > +	}
> > +
> > +	/* turn RNG h/w on, if it's off */
> > +	if ((hw_status & INTEL_RNG_ENABLED) == 0)
> > +		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;
> > +		goto err_out_free_map;
> > +	}
> > +
> > +	DPRINTK ("EXIT, returning 0\n");
> > +	return 0;
> > +
> > +err_out_free_map:
> > +	iounmap (rng_mem);
> > +err_out:
> > +	DPRINTK ("EXIT, returning %d\n", rc);
> > +	return rc;
> > +}
> > +
> [skip]
> > +static int __init amd_init(struct hwrng *rng)
> 
> Again, __init is wrong.
> 
> [skip]
> > +static int __init via_init(struct hwrng *rng)
> 
> This __init is wrong too.
> 
> [skip]
> 

Ah, and I found another bug in hwrng_unregister:
	current_rng = list_entry(rng_list.prev, struct hwrng, list);
current_rng->init() should be called here (if nonNULL). If that fails
current_rng = NULL;

Will fix that, too.

-- 
Greetings Michael.

Re: [patch 3/6] New Generic HW RNG (#2)

[Sergey Vlasov]

[-- Attachment #1: Type: text/plain, Size: 1529 bytes --]

On Sun, May 07, 2006 at 05:39:44PM +0200, Michael Buesch wrote:
> On Sunday 07 May 2006 17:22, you wrote:
> > On Sun, May 07, 2006 at 04:38:09PM +0200, Michael Buesch wrote:
> > > Add a driver for the x86 RNG.
> > > This driver is ported from the old hw_random.c
> > > 
> > [skip]
> > > +static int __init intel_init(struct hwrng *rng)
> > 
> > Cannot be __init anymore - now rng->init could be called at any time.
> 
> Sure, will fix this.
> 
> > Also, there is another problem with putting this function into
> > rng->init - if another RNG has been registered when this module is
> > loaded, ->init will not be called during hwrng_register(), so the
> > module load will succeed even if the chipset does not have RNG
> > hardware.
> 
> Ok, I see. The question is, are we going to hwrng_register() the
> intel, althought there is no device? We check for the PCI IDs.

Most Intel chipset do not really have the hardware RNG - PCI ID
matches, but the check for INTEL_RNG_PRESENT bit in intel_init()
fails.  (In fact, I have not ever seen a board which had that RNG.)

[skip]

> Ah, and I found another bug in hwrng_unregister:
> 	current_rng = list_entry(rng_list.prev, struct hwrng, list);
> current_rng->init() should be called here (if nonNULL). If that fails
> current_rng = NULL;

All that logic in hwrng_register() and hwrng_unregister() looks overly
complex.  Maybe we should just register the miscdevice
unconditionally, and make it return -ENODEV from open() if no RNG is
registered?

[-- Attachment #2: Type: application/pgp-signature, Size: 191 bytes --]

[patch 4/6] New Generic HW RNG (#2)

[Michael Buesch]

[-- Attachment #1: add-ixp4xx-hw-random.patch --]
[-- Type: text/plain, Size: 3197 bytes --]

Add ixp4xx H/W RNG driver.
Driver written by Deepak Saxena.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Index: hwrng/drivers/char/hw_random/Kconfig
===================================================================
--- hwrng.orig/drivers/char/hw_random/Kconfig	2006-05-07 15:50:22.000000000 +0200
+++ hwrng/drivers/char/hw_random/Kconfig	2006-05-07 15:50:25.000000000 +0200
@@ -22,3 +22,15 @@
 	  module will be called x86-rng.
 
 	  If unsure, say Y.
+
+config IXP4XX_RNG
+	tristate "Intel IXP4xx NPU HW Random Number Generator support"
+	depends on HW_RANDOM && ARCH_IXP4XX
+	---help---
+	  This driver provides kernel-side support for the Random
+	  Number Generator hardware found on the Intel IXP4xx NPU.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ixp4xx-rng.
+
+	  If unsure, say Y.
Index: hwrng/drivers/char/hw_random/Makefile
===================================================================
--- hwrng.orig/drivers/char/hw_random/Makefile	2006-05-07 15:50:22.000000000 +0200
+++ hwrng/drivers/char/hw_random/Makefile	2006-05-07 15:50:25.000000000 +0200
@@ -4,3 +4,4 @@
 
 obj-$(CONFIG_HW_RANDOM) += core.o
 obj-$(CONFIG_X86_RNG) += x86-rng.o
+obj-$(CONFIG_IXP4XX_RNG) += ixp4xx-rng.o
Index: hwrng/drivers/char/hw_random/ixp4xx-rng.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ hwrng/drivers/char/hw_random/ixp4xx-rng.c	2006-05-07 15:50:25.000000000 +0200
@@ -0,0 +1,73 @@
+/*
+ * drivers/char/rng/ixp4xx-rng.c
+ *
+ * RNG driver for Intel IXP4xx family of NPUs
+ *
+ * Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ * Copyright 2005 (c) MontaVista Software, Inc.
+ *
+ * Fixes by Michael Buesch
+ *
+ * This file is licensed under  the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/hw_random.h>
+
+#include <asm/io.h>
+#include <asm/hardware.h>
+
+
+static int ixp4xx_rng_data_read(struct hwrng *rng, u32 *buffer)
+{
+	void __iomem * rng_base = (void __iomem *)rng->priv;
+
+	*buffer = __raw_readl(rng_base);
+
+	return 4;
+}
+
+static struct hwrng ixp4xx_rng_ops = {
+	.name		= "ixp4xx",
+	.data_read	= ixp4xx_rng_data_read,
+};
+
+static int __init ixp4xx_rng_init(void)
+{
+	void __iomem * rng_base;
+	int err;
+
+	rng_base = ioremap(0x70002100, 4);
+	if (!rng_base)
+		return -ENOMEM;
+	ixp4xx_rng_ops.priv = (unsigned long)rng_base;
+	err = hwrng_register(&ixp4xx_rng_ops);
+	if (err)
+		iounmap(rng_base);
+
+	return err;
+}
+
+static void __exit ixp4xx_rng_exit(void)
+{
+	void __iomem * rng_base = (void __iomem *)ixp4xx_rng_ops.priv;
+
+	hwrng_unregister(&ixp4xx_rng_ops);
+	iounmap(rng_base);
+}
+
+subsys_initcall(ixp4xx_rng_init);
+module_exit(ixp4xx_rng_exit);
+
+MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
+MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver for IXP4xx");
+MODULE_LICENSE("GPL");

--

[patch 5/6] New Generic HW RNG (#2)

[Michael Buesch]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: add-omap-hw-random.patch --]
[-- Type: text/plain, Size: 6219 bytes --]

Add H/W RNG driver for TI OMAP CPU family.
Driver written by Deepak Saxena.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Index: hwrng/drivers/char/hw_random/Kconfig
===================================================================
--- hwrng.orig/drivers/char/hw_random/Kconfig	2006-05-07 15:50:25.000000000 +0200
+++ hwrng/drivers/char/hw_random/Kconfig	2006-05-07 15:50:29.000000000 +0200
@@ -34,3 +34,16 @@
 	  module will be called ixp4xx-rng.
 
 	  If unsure, say Y.
+
+config OMAP_RNG
+	tristate "OMAP Random Number Generator support"
+	depends on HW_RANDOM && (ARCH_OMAP16XX || ARCH_OMAP24XX)
+ 	---help---
+ 	  This driver provides kernel-side support for the Random Number
+	  Generator hardware found on OMAP16xx and OMAP24xx multimedia
+	  processors.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called omap-rng.
+
+ 	  If unsure, say Y.
Index: hwrng/drivers/char/hw_random/Makefile
===================================================================
--- hwrng.orig/drivers/char/hw_random/Makefile	2006-05-07 15:50:25.000000000 +0200
+++ hwrng/drivers/char/hw_random/Makefile	2006-05-07 15:50:29.000000000 +0200
@@ -5,3 +5,4 @@
 obj-$(CONFIG_HW_RANDOM) += core.o
 obj-$(CONFIG_X86_RNG) += x86-rng.o
 obj-$(CONFIG_IXP4XX_RNG) += ixp4xx-rng.o
+obj-$(CONFIG_OMAP_RNG) += omap-rng.o
Index: hwrng/drivers/char/hw_random/omap-rng.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ hwrng/drivers/char/hw_random/omap-rng.c	2006-05-07 15:50:29.000000000 +0200
@@ -0,0 +1,208 @@
+/*
+ * driver/char/hw_random/omap-rng.c
+ *
+ * RNG driver for TI OMAP CPU family
+ *
+ * Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ * Copyright 2005 (c) MontaVista Software, Inc.
+ *
+ * Mostly based on original driver:
+ *
+ * Copyright (C) 2005 Nokia Corporation
+ * Author: Juha Yrj��<juha.yrjola@nokia.com>
+ *
+ * This file is licensed under  the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * TODO:
+ *
+ * - Make status updated be interrupt driven so we don't poll
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/random.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/hw_random.h>
+
+#include <asm/io.h>
+#include <asm/hardware/clock.h>
+
+#define RNG_OUT_REG		0x00		/* Output register */
+#define RNG_STAT_REG		0x04		/* Status register
+							[0] = STAT_BUSY */
+#define RNG_ALARM_REG		0x24		/* Alarm register
+							[7:0] = ALARM_COUNTER */
+#define RNG_CONFIG_REG		0x28		/* Configuration register
+							[11:6] = RESET_COUNT
+							[5:3]  = RING2_DELAY
+							[2:0]  = RING1_DELAY */
+#define RNG_REV_REG		0x3c		/* Revision register
+							[7:0] = REV_NB */
+#define RNG_MASK_REG		0x40		/* Mask and reset register
+							[2] = IT_EN
+							[1] = SOFTRESET
+							[0] = AUTOIDLE */
+#define RNG_SYSSTATUS		0x44		/* System status
+							[0] = RESETDONE */
+
+static void __iomem *rng_base;
+static struct clk *rng_ick;
+static struct device *rng_dev;
+
+static u32 omap_rng_read_reg(int reg)
+{
+	return __raw_readl(rng_base + reg);
+}
+
+static void omap_rng_write_reg(int reg, u32 val)
+{
+	__raw_writel(val, rng_base + reg);
+}
+
+/* REVISIT: Does the status bit really work on 16xx? */
+static int omap_rng_data_present(struct hwrng *rng)
+{
+	return omap_rng_read_reg(RNG_STAT_REG) ? 0 : 1;
+}
+
+static int omap_rng_data_read(struct hwrng *rng, u32 *data)
+{
+	*data = omap_rng_read_reg(RNG_OUT_REG);
+
+	return 4;
+}
+
+static struct hwrng omap_rng_ops = {
+	.name		= "omap",
+	.data_present	= omap_rng_data_present,
+	.data_read	= omap_rng_data_read,
+};
+
+static int __init omap_rng_probe(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct resource *res, *mem;
+	int ret;
+
+	/*
+	 * A bit ugly, and it will never actually happen but there can
+	 * be only one RNG and this catches any bork
+	 */
+	BUG_ON(rng_dev);
+
+    	if (cpu_is_omap24xx()) {
+		rng_ick = clk_get(NULL, "rng_ick");
+		if (IS_ERR(rng_ick)) {
+			dev_err(dev, "Could not get rng_ick\n");
+			ret = PTR_ERR(rng_ick);
+			return ret;
+		}
+		else {
+			clk_use(rng_ick);
+		}
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	if (!res)
+		return -ENOENT;
+
+	mem = request_mem_region(res->start, res->end - res->start + 1,
+				 pdev->name);
+	if (mem == NULL)
+		return -EBUSY;
+
+	dev_set_drvdata(dev, mem);
+	rng_base = (u32 __iomem *)io_p2v(res->start);
+
+	ret = hwrng_register(&omap_rng_ops);
+	if (ret) {
+		release_resource(mem);
+		rng_base = NULL;
+		return ret;
+	}
+
+	dev_info(dev, "OMAP Random Number Generator ver. %02x\n",
+		omap_rng_read_reg(RNG_REV_REG));
+	omap_rng_write_reg(RNG_MASK_REG, 0x1);
+
+	rng_dev = dev;
+
+	return 0;
+}
+
+static int __exit omap_rng_remove(struct device *dev)
+{
+	struct resource *mem = dev_get_drvdata(dev);
+
+	hwrng_unregister(&omap_rng_ops);
+
+	omap_rng_write_reg(RNG_MASK_REG, 0x0);
+
+	if (cpu_is_omap24xx()) {
+		clk_unuse(rng_ick);
+		clk_put(rng_ick);
+	}
+
+	release_resource(mem);
+	rng_base = NULL;
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int omap_rng_suspend(struct device *dev, pm_message_t message, u32 level)
+{
+	omap_rng_write_reg(RNG_MASK_REG, 0x0);
+
+	return 0;
+}
+
+static int omap_rng_resume(struct device *dev, pm_message_t message, u32 level)
+{
+	omap_rng_write_reg(RNG_MASK_REG, 0x1);
+
+	return 1;
+}
+
+#else
+
+#define	omap_rng_suspend	NULL
+#define	omap_rng_resume		NULL
+
+#endif
+
+
+static struct device_driver omap_rng_driver = {
+	.name		= "omap_rng",
+	.bus		= &platform_bus_type,
+	.probe		= omap_rng_probe,
+	.remove		= __exit_p(omap_rng_remove),
+	.suspend	= omap_rng_suspend,
+	.resume		= omap_rng_resume
+};
+
+static int __init omap_rng_init(void)
+{
+	if (!cpu_is_omap16xx() && !cpu_is_omap24xx())
+		return -ENODEV;
+
+	return driver_register(&omap_rng_driver);
+}
+
+static void __exit omap_rng_exit(void)
+{
+	driver_unregister(&omap_rng_driver);
+}
+
+module_init(omap_rng_init);
+module_exit(omap_rng_exit);
+
+MODULE_AUTHOR("Deepak Saxena (and others)");
+MODULE_LICENSE("GPL");

--

[patch 6/6] New Generic HW RNG (#2)

[Michael Buesch]

[-- Attachment #1: bcm43xx-hw-random.patch --]
[-- Type: text/plain, Size: 3596 bytes --]

Add bcm43xx H/W RNG support.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Index: hwrng/drivers/net/wireless/bcm43xx/Kconfig
===================================================================
--- hwrng.orig/drivers/net/wireless/bcm43xx/Kconfig	2006-05-07 15:47:21.000000000 +0200
+++ hwrng/drivers/net/wireless/bcm43xx/Kconfig	2006-05-07 15:50:32.000000000 +0200
@@ -2,6 +2,7 @@
 	tristate "Broadcom BCM43xx wireless support"
 	depends on PCI && IEEE80211 && IEEE80211_SOFTMAC && NET_RADIO && EXPERIMENTAL
 	select FW_LOADER
+	select HW_RANDOM
 	---help---
 	  This is an experimental driver for the Broadcom 43xx wireless chip,
 	  found in the Apple Airport Extreme and various other devices.
Index: hwrng/drivers/net/wireless/bcm43xx/bcm43xx.h
===================================================================
--- hwrng.orig/drivers/net/wireless/bcm43xx/bcm43xx.h	2006-05-07 15:47:21.000000000 +0200
+++ hwrng/drivers/net/wireless/bcm43xx/bcm43xx.h	2006-05-07 15:50:32.000000000 +0200
@@ -1,6 +1,7 @@
 #ifndef BCM43xx_H_
 #define BCM43xx_H_
 
+#include <linux/hw_random.h>
 #include <linux/version.h>
 #include <linux/kernel.h>
 #include <linux/spinlock.h>
@@ -82,6 +83,7 @@
 #define BCM43xx_MMIO_TSF_1		0x634 /* core rev < 3 only */
 #define BCM43xx_MMIO_TSF_2		0x636 /* core rev < 3 only */
 #define BCM43xx_MMIO_TSF_3		0x638 /* core rev < 3 only */
+#define BCM43xx_MMIO_RNG		0x65A
 #define BCM43xx_MMIO_POWERUP_DELAY	0x6A8
 
 /* SPROM offsets. */
@@ -741,6 +743,10 @@
 	const struct firmware *initvals0;
 	const struct firmware *initvals1;
 
+	/* Random Number Generator. */
+	struct hwrng rng;
+	char rng_name[20 + 1];
+
 	/* Debugging stuff follows. */
 #ifdef CONFIG_BCM43XX_DEBUG
 	struct bcm43xx_dfsentry *dfsentry;
Index: hwrng/drivers/net/wireless/bcm43xx/bcm43xx_main.c
===================================================================
--- hwrng.orig/drivers/net/wireless/bcm43xx/bcm43xx_main.c	2006-05-07 15:47:21.000000000 +0200
+++ hwrng/drivers/net/wireless/bcm43xx/bcm43xx_main.c	2006-05-07 15:50:32.000000000 +0200
@@ -3144,6 +3144,39 @@
 	bcm43xx_clear_keys(bcm);
 }
 
+static int bcm43xx_rng_read(struct hwrng *rng, u32 *data)
+{
+	struct bcm43xx_private *bcm = (struct bcm43xx_private *)rng->priv;
+	unsigned long flags;
+
+	bcm43xx_lock(bcm, flags);
+	*data = bcm43xx_read16(bcm, BCM43xx_MMIO_RNG);
+	bcm43xx_unlock(bcm, flags);
+
+	return (sizeof(u16));
+}
+
+static void bcm43xx_rng_exit(struct bcm43xx_private *bcm)
+{
+	hwrng_unregister(&bcm->rng);
+}
+
+static int bcm43xx_rng_init(struct bcm43xx_private *bcm)
+{
+	int err;
+
+	snprintf(bcm->rng_name, ARRAY_SIZE(bcm->rng_name),
+		 "%s_%s", KBUILD_MODNAME, bcm->net_dev->name);
+	bcm->rng.name = bcm->rng_name;
+	bcm->rng.data_read = bcm43xx_rng_read;
+	bcm->rng.priv = (unsigned long)bcm;
+	err = hwrng_register(&bcm->rng);
+	if (err)
+		printk(KERN_ERR PFX "RNG init failed (%d)\n", err);
+
+	return err;
+}
+
 /* This is the opposite of bcm43xx_init_board() */
 static void bcm43xx_free_board(struct bcm43xx_private *bcm)
 {
@@ -3159,6 +3192,7 @@
 	bcm->shutting_down = 1;
 	bcm43xx_unlock(bcm, flags);
 
+	bcm43xx_rng_exit(bcm);
 	for (i = 0; i < BCM43xx_MAX_80211_CORES; i++) {
 		if (!bcm->core_80211[i].available)
 			continue;
@@ -3240,6 +3274,9 @@
 		bcm43xx_switch_core(bcm, &bcm->core_80211[0]);
 		bcm43xx_mac_enable(bcm);
 	}
+	err = bcm43xx_rng_init(bcm);
+	if (err)
+		goto err_80211_unwind;
 	bcm43xx_macfilter_clear(bcm, BCM43xx_MACFILTER_ASSOC);
 	bcm43xx_macfilter_set(bcm, BCM43xx_MACFILTER_SELF, (u8 *)(bcm->net_dev->dev_addr));
 	dprintk(KERN_INFO PFX "80211 cores initialized\n");

--

Re: [patch 0/6] New Generic HW RNG (#2)

[Arnd Bergmann]

On Sunday 07 May 2006 16:38, Michael Buesch wrote:
> Second try. Various fixes included. This does even compile (and work) now. :)
> 

It would be good to give the patches more descriptive names, currently
they all have the same subject lines, which is not really helpful.

> The userspace RNG daemon can later be updated to select the RNG through
> /sys/class/misc/hw_random/ for convenience. For now it is sufficient to
> use cat and echo -n on the sysfs attributes.  

When you're making the behaviour of hw_random configurable, maybe you could
also add an option to automatically use the current hw_random driver to
feed the /dev/random entropy pool on systems where the administrator trusts
its randomness.

	Arnd <><

Re: [patch 0/6] New Generic HW RNG (#2)

[Michael Buesch]

On Sunday 07 May 2006 20:39, you wrote:
> On Sunday 07 May 2006 16:38, Michael Buesch wrote:
> > Second try. Various fixes included. This does even compile (and work) now. :)
> > 
> 
> It would be good to give the patches more descriptive names, currently
> they all have the same subject lines, which is not really helpful.

How to do this with quilt?

> > The userspace RNG daemon can later be updated to select the RNG through
> > /sys/class/misc/hw_random/ for convenience. For now it is sufficient to
> > use cat and echo -n on the sysfs attributes.  
> 
> When you're making the behaviour of hw_random configurable, maybe you could
> also add an option to automatically use the current hw_random driver to
> feed the /dev/random entropy pool on systems where the administrator trusts
> its randomness.

This has been discussed and it is not desired behaviour.
If you want to feed /dev/random, use rngd to read from /dev/hwrng,
validate the data and put it into /dev/random.

-- 
Greetings Michael.

Re: [patch 0/6] New Generic HW RNG (#2)

[Arnd Bergmann]

On Sunday 07 May 2006 20:50, Michael Buesch wrote:
> 
> > It would be good to give the patches more descriptive names, currently
> > they all have the same subject lines, which is not really helpful.
> 
> How to do this with quilt?

Change the first line in each patch header to

Subject: <what this patch does>

> This has been discussed and it is not desired behaviour.
> If you want to feed /dev/random, use rngd to read from /dev/hwrng,
> validate the data and put it into /dev/random.

ok

	Arnd <><