From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: linux-kernel@vger.kernel.org
Subject: PATCH: 2.5 Forward port AMD random number generator
Date: 02 Oct 2002 22:58:37 +0100 [thread overview]
Message-ID: <1033595917.25260.6.camel@irongate.swansea.linux.org.uk> (raw)
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.2.5.40/drivers/char/amd768_rng.c linux.2.5.40-ac1/drivers/char/amd768_rng.c
--- linux.2.5.40/drivers/char/amd768_rng.c 1970-01-01 01:00:00.000000000 +0100
+++ linux.2.5.40-ac1/drivers/char/amd768_rng.c 2002-10-02 22:29:55.000000000 +0100
@@ -0,0 +1,295 @@
+/*
+ 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@mandrakesoft.com>
+ Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
+
+ Please read Documentation/i810_rng.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>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+
+/*
+ * core module and version information
+ */
+#define RNG_VERSION "0.1.0"
+#define RNG_MODULE_NAME "amd768_rng"
+#define RNG_DRIVER_NAME RNG_MODULE_NAME " hardware driver " RNG_VERSION
+#define PFX RNG_MODULE_NAME ": "
+
+
+/*
+ * debugging macros
+ */
+#undef RNG_DEBUG /* define to enable copious debugging info */
+
+#ifdef RNG_DEBUG
+/* note: prints function name for you */
+#define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt, __FUNCTION__ , ## args)
+#else
+#define DPRINTK(fmt, args...)
+#endif
+
+#undef RNG_NDEBUG /* define to disable lightweight runtime checks */
+#ifdef RNG_NDEBUG
+#define assert(expr)
+#else
+#define assert(expr) \
+ if(!(expr)) { \
+ printk( "Assertion failed! %s,%s,%s,line=%d\n", \
+ #expr,__FILE__,__FUNCTION__,__LINE__); \
+ }
+#endif
+
+#define RNG_MISCDEV_MINOR 183 /* official */
+
+/*
+ * various RNG status variables. they are globals
+ * as we only support a single RNG device
+ */
+
+static u32 pmbase; /* PMxx I/O base */
+static struct semaphore rng_open_sem; /* Semaphore for serializing rng_open/release */
+
+
+/*
+ * inlined helper functions for accessing RNG registers
+ */
+
+static inline int rng_data_present (void)
+{
+ return inl(pmbase+0xF4) & 1;
+}
+
+
+static inline int rng_data_read (void)
+{
+ return inl(pmbase+0xF0);
+}
+
+static int rng_dev_open (struct inode *inode, struct file *filp)
+{
+ if ((filp->f_mode & FMODE_READ) == 0)
+ return -EINVAL;
+ if (filp->f_mode & FMODE_WRITE)
+ return -EINVAL;
+
+ /* wait for device to become free */
+ if (filp->f_flags & O_NONBLOCK) {
+ if (down_trylock (&rng_open_sem))
+ return -EAGAIN;
+ } else {
+ if (down_interruptible (&rng_open_sem))
+ return -ERESTARTSYS;
+ }
+ return 0;
+}
+
+
+static int rng_dev_release (struct inode *inode, struct file *filp)
+{
+ up(&rng_open_sem);
+ return 0;
+}
+
+
+static ssize_t rng_dev_read (struct file *filp, char *buf, size_t size,
+ loff_t * offp)
+{
+ static spinlock_t rng_lock = SPIN_LOCK_UNLOCKED;
+ int have_data;
+ u32 data = 0;
+ ssize_t ret = 0;
+
+ while (size) {
+ spin_lock(&rng_lock);
+
+ have_data = 0;
+ if (rng_data_present()) {
+ data = rng_data_read();
+ have_data = 4;
+ }
+
+ spin_unlock (&rng_lock);
+
+ while (have_data > 0) {
+ 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())
+ {
+ current->state = TASK_INTERRUPTIBLE;
+ schedule_timeout(1);
+ }
+ else
+ udelay(200); /* FIXME: We could poll for 250uS ?? */
+
+ if (signal_pending (current))
+ return ret ? : -ERESTARTSYS;
+ }
+ return ret;
+}
+
+
+static struct file_operations rng_chrdev_ops = {
+ owner: THIS_MODULE,
+ open: rng_dev_open,
+ release: rng_dev_release,
+ read: rng_dev_read,
+};
+
+
+static struct miscdevice rng_miscdev = {
+ RNG_MISCDEV_MINOR,
+ RNG_MODULE_NAME,
+ &rng_chrdev_ops,
+};
+
+
+/*
+ * rng_init_one - look for and attempt to init a single RNG
+ */
+static int __init rng_init_one (struct pci_dev *dev)
+{
+ int rc;
+ u8 rnen;
+
+ DPRINTK ("ENTER\n");
+
+ rc = misc_register (&rng_miscdev);
+ if (rc) {
+ printk (KERN_ERR PFX "cannot register misc device\n");
+ DPRINTK ("EXIT, returning %d\n", rc);
+ goto err_out;
+ }
+
+ pci_read_config_dword(dev, 0x58, &pmbase);
+
+ pmbase&=0x0000FF00;
+
+ if(pmbase == 0)
+ {
+ printk (KERN_ERR PFX "power management base not set\n");
+ DPRINTK ("EXIT, returning %d\n", rc);
+ goto err_out_free_miscdev;
+ }
+
+ 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);
+
+ printk(KERN_INFO PFX "AMD768 system management I/O registers at 0x%X.\n", pmbase);
+ DPRINTK ("EXIT, returning 0\n");
+ return 0;
+
+err_out_free_miscdev:
+ misc_deregister (&rng_miscdev);
+err_out:
+ return rc;
+}
+
+
+/*
+ * 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[] __initdata = {
+ { 0x1022, 0x7443, PCI_ANY_ID, PCI_ANY_ID, },
+ { 0, },
+};
+MODULE_DEVICE_TABLE (pci, rng_pci_tbl);
+
+
+MODULE_AUTHOR("Alan Cox, Jeff Garzik, Philipp Rumpf, Matt Sottek");
+MODULE_DESCRIPTION("AMD 768 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;
+
+ DPRINTK ("ENTER\n");
+
+ init_MUTEX (&rng_open_sem);
+
+ pci_for_each_dev(pdev) {
+ if (pci_match_device (rng_pci_tbl, pdev) != NULL)
+ goto match;
+ }
+
+ DPRINTK ("EXIT, returning -ENODEV\n");
+ return -ENODEV;
+
+match:
+ rc = rng_init_one (pdev);
+ if (rc)
+ return rc;
+
+ printk (KERN_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);
+ DPRINTK ("EXIT\n");
+}
+
+
+module_init (rng_init);
+module_exit (rng_cleanup);
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.2.5.40/drivers/char/Config.help linux.2.5.40-ac1/drivers/char/Config.help
--- linux.2.5.40/drivers/char/Config.help 2002-10-02 21:33:46.000000000 +0100
+++ linux.2.5.40-ac1/drivers/char/Config.help 2002-10-02 22:22:38.000000000 +0100
@@ -648,6 +648,21 @@
If unsure, say N.
+CONFIG_AMD_RNG
+ This driver provides kernel-side support for the Random Number
+ Generator hardware found on AMD 76x based motherboards.
+
+ Both a character driver, used to read() entropy data, and a timer
+ function which automatically adds entropy directly into the
+ kernel pool, are exported by this driver.
+
+ To compile this driver as a module ( = code which can be inserted in
+ and removed from the running kernel whenever you want), say M here
+ and read <file:Documentation/modules.txt>. The module will be called
+ i810_rng.o.
+
+ If unsure, say N.
+
CONFIG_WATCHDOG
If you say Y here (and to one of the following options) and create a
character special file /dev/watchdog with major number 10 and minor
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.2.5.40/drivers/char/Config.in linux.2.5.40-ac1/drivers/char/Config.in
--- linux.2.5.40/drivers/char/Config.in 2002-10-02 21:33:46.000000000 +0100
+++ linux.2.5.40-ac1/drivers/char/Config.in 2002-10-02 22:21:19.000000000 +0100
@@ -149,6 +149,9 @@
if [ "$CONFIG_X86" = "y" -o "$CONFIG_IA64" = "y" ]; then
dep_tristate 'Intel i8x0 Random Number Generator support' CONFIG_INTEL_RNG $CONFIG_PCI
fi
+if [ "$CONFIG_X86" = "y" ]; then
+ dep_tristate 'AMD 768 Random Number Generator support' CONFIG_AMD_RNG $CONFIG_PCI
+fi
tristate '/dev/nvram support' CONFIG_NVRAM
tristate 'Enhanced Real Time Clock Support' CONFIG_RTC
if [ "$CONFIG_RTC" != "y" ]; then
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.2.5.40/drivers/char/Makefile linux.2.5.40-ac1/drivers/char/Makefile
--- linux.2.5.40/drivers/char/Makefile 2002-10-02 21:33:52.000000000 +0100
+++ linux.2.5.40-ac1/drivers/char/Makefile 2002-10-02 22:22:56.000000000 +0100
@@ -67,6 +67,7 @@
obj-$(CONFIG_I8K) += i8k.o
obj-$(CONFIG_DS1620) += ds1620.o
obj-$(CONFIG_INTEL_RNG) += i810_rng.o
+obj-$(CONFIG_AMD_RNG) += amd768_rng.o
obj-$(CONFIG_QIC02_TAPE) += tpqic02.o
obj-$(CONFIG_FTAPE) += ftape/
obj-$(CONFIG_H8) += h8.o
reply other threads:[~2002-10-02 21:45 UTC|newest]
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