From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271183AbTHHC4b (ORCPT ); Thu, 7 Aug 2003 22:56:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271174AbTHHC4b (ORCPT ); Thu, 7 Aug 2003 22:56:31 -0400 Received: from host-64-213-145-173.atlantasolutions.com ([64.213.145.173]:24986 "EHLO havoc.gtf.org") by vger.kernel.org with ESMTP id S271187AbTHHCzD (ORCPT ); Thu, 7 Aug 2003 22:55:03 -0400 Date: Thu, 7 Aug 2003 22:55:02 -0400 From: Jeff Garzik To: linux-kernel@vger.kernel.org Subject: [patch 2.4 2/2] add hw_random RNG driver Message-ID: <20030808025502.GA31909@gtf.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org # # drivers/char/Config.in 1.48 -> 1.49 # Documentation/Configure.help 1.176 -> 1.177 # drivers/char/Makefile 1.34 -> 1.35 # (new) -> 1.1 drivers/char/hw_random.c # (new) -> 1.2 Documentation/hw_random.txt # # -------------------------------------------- # 03/08/07 jgarzik@redhat.com 1.1067 # [hw_random] add combined Intel+AMD+VIA h/w RNG driver # -------------------------------------------- # diff -Nru a/Documentation/Configure.help b/Documentation/Configure.help --- a/Documentation/Configure.help Thu Aug 7 22:51:42 2003 +++ b/Documentation/Configure.help Thu Aug 7 22:51:43 2003 @@ -18797,6 +18797,21 @@ If unsure, say N. +Intel/AMD/VIA HW Random Number Generator support +CONFIG_HW_RANDOM + 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 ( = code which can be inserted in + and removed from the running kernel whenever you want), say M here + and read . The module will be called + hw_random. + + If unsure, say N. + Power Management support CONFIG_PM "Power Management" means that parts of your computer are shut diff -Nru a/Documentation/hw_random.txt b/Documentation/hw_random.txt --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/Documentation/hw_random.txt Thu Aug 7 22:51:43 2003 @@ -0,0 +1,138 @@ + Hardware driver for Intel/AMD/VIA Random Number Generators (RNG) + Copyright 2000,2001 Jeff Garzik + Copyright 2000,2001 Philipp Rumpf + +Introduction: + + The hw_random device driver is software that makes use of a + special hardware feature on your CPU or motherboard, + a Random Number Generator (RNG). + + In order to make effective use of this device driver, you + should download the support software as well. Download the + latest version of the "rng-tools" package from the + hw_random driver's official Web site: + + http://sourceforge.net/projects/gkernel/ + +About the Intel RNG hardware, from the firmware hub datasheet: + + The Firmware Hub integrates a Random Number Generator (RNG) + using thermal noise generated from inherently random quantum + mechanical properties of silicon. When not generating new random + bits the RNG circuitry will enter a low power state. Intel will + provide a binary software driver to give third party software + access to our RNG for use as a security feature. At this time, + the RNG is only to be used with a system in an OS-present state. + +Theory of operation: + + Character driver. Using the standard open() + and read() system calls, you can read random data from + the hardware RNG device. This data is NOT CHECKED by any + fitness tests, and could potentially be bogus (if the + hardware is faulty or has been tampered with). Data is only + output if the hardware "has-data" flag is set, but nevertheless + a security-conscious person would run fitness tests on the + data before assuming it is truly random. + + /dev/hwrandom is char device major 10, minor 183. + +Driver notes: + + * FIXME: support poll(2) + + NOTE: request_mem_region was removed, for two reasons: + 1) Only one RNG is supported by this driver, 2) The location + used by the RNG is a fixed location in MMIO-addressable memory, + 3) users with properly working BIOS e820 handling will always + have the region in which the RNG is located reserved, so + request_mem_region calls always fail for proper setups. + However, for people who use mem=XX, BIOS e820 information is + -not- in /proc/iomem, and request_mem_region(RNG_ADDR) can + succeed. + +Driver details: + + Based on: + Intel 82802AB/82802AC Firmware Hub (FWH) Datasheet + May 1999 Order Number: 290658-002 R + + Intel 82802 Firmware Hub: Random Number Generator + Programmer's Reference Manual + December 1999 Order Number: 298029-001 R + + Intel 82802 Firmware HUB Random Number Generator Driver + Copyright (c) 2000 Matt Sottek + + Special thanks to Matt Sottek. I did the "guts", he + did the "brains" and all the testing. + +Change history: + + Version 1.0.0: + * Merge Intel, AMD, VIA RNG drivers into one. + Further changelog in BitKeeper. + + Version 0.9.8: + * Support other i8xx chipsets by adding 82801E detection + * 82801DB detection is the same as for 82801CA. + + Version 0.9.7: + * Support other i8xx chipsets too (by adding 82801BA(M) and + 82801CA(M) detection) + + Version 0.9.6: + * Internal driver cleanups, prep for 1.0.0 release. + + Version 0.9.5: + * Rip out entropy injection via timer. It never ever worked, + and a better solution (rngd) is now available. + + Version 0.9.4: + * Fix: Remove request_mem_region + * Fix: Horrible bugs in FIPS calculation and test execution + + Version 0.9.3: + * Clean up rng_read a bit. + * Update i810_rng driver Web site URL. + * Increase default timer interval to 4 samples per second. + * Abort if mem region is not available. + * BSS zero-initialization cleanup. + * Call misc_register() from rng_init_one. + * Fix O_NONBLOCK to occur before we schedule. + + Version 0.9.2: + * Simplify open blocking logic + + Version 0.9.1: + * Support i815 chipsets too (Matt Sottek) + * Fix reference counting when statically compiled (prumpf) + * Rewrite rng_dev_read (prumpf) + * Make module races less likely (prumpf) + * Small miscellaneous bug fixes (prumpf) + * Use pci table for PCI id list + + Version 0.9.0: + * Don't register a pci_driver, because we are really + using PCI bridge vendor/device ids, and someone + may want to register a driver for the bridge. (bug fix) + * Don't let the usage count go negative (bug fix) + * Clean up spinlocks (bug fix) + * Enable PCI device, if necessary (bug fix) + * iounmap on module unload (bug fix) + * If RNG chrdev is already in use when open(2) is called, + sleep until it is available. + * Remove redundant globals rng_allocated, rng_use_count + * Convert numeric globals to unsigned + * Module unload cleanup + + Version 0.6.2: + * Clean up spinlocks. Since we don't have any interrupts + to worry about, but we do have a timer to worry about, + we use spin_lock_bh everywhere except the timer function + itself. + * Fix module load/unload. + * Fix timer function and h/w enable/disable logic + * New timer interval sysctl + * Clean up sysctl names diff -Nru a/drivers/char/Config.in b/drivers/char/Config.in --- a/drivers/char/Config.in Thu Aug 7 22:51:42 2003 +++ b/drivers/char/Config.in Thu Aug 7 22:51:42 2003 @@ -267,6 +267,10 @@ 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" -o "$CONFIG_IA64" = "y" -o \ + "$CONFIG_X86_64" = "y" ]; then + dep_tristate 'Intel/AMD/VIA HW Random Number Generator support' CONFIG_HW_RANDOM $CONFIG_PCI +fi dep_tristate 'AMD 76x native power management (Experimental)' CONFIG_AMD_PM768 $CONFIG_PCI tristate '/dev/nvram support' CONFIG_NVRAM tristate 'Enhanced Real Time Clock Support' CONFIG_RTC diff -Nru a/drivers/char/Makefile b/drivers/char/Makefile --- a/drivers/char/Makefile Thu Aug 7 22:51:43 2003 +++ b/drivers/char/Makefile Thu Aug 7 22:51:43 2003 @@ -247,6 +247,7 @@ obj-$(CONFIG_DS1620) += ds1620.o obj-$(CONFIG_INTEL_RNG) += i810_rng.o obj-$(CONFIG_AMD_RNG) += amd768_rng.o +obj-$(CONFIG_HW_RANDOM) += hw_random.o obj-$(CONFIG_AMD_PM768) += amd76x_pm.o obj-$(CONFIG_BRIQ_PANEL) += briq_panel.o diff -Nru a/drivers/char/hw_random.c b/drivers/char/hw_random.c --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/drivers/char/hw_random.c Thu Aug 7 22:51:43 2003 @@ -0,0 +1,631 @@ +/* + Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG) + (c) Copyright 2003 Red Hat Inc + + derived from + + Hardware driver for the AMD 768 Random Number Generator (RNG) + (c) Copyright 2001 Red Hat Inc + + derived from + + Hardware driver for Intel i810 Random Number Generator (RNG) + Copyright 2000,2001 Jeff Garzik + Copyright 2000,2001 Philipp Rumpf + + 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef __i386__ +#include +#include +#endif + +#include +#include + + +/* + * 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 + */ +#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 + +#define 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 */ + +static int rng_dev_open (struct inode *inode, struct file *filp); +static ssize_t rng_dev_read (struct file *filp, char *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 via_init(struct pci_dev *dev); +static void via_cleanup(void); +static unsigned int via_data_present (void); +static u32 via_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, + rng_hw_via, +}; + +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 }, + + /* rng_hw_via */ + { via_init, via_cleanup, via_data_present, via_data_read, 1 }, +}; + +/* + * 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, 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, 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 }, + + { 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 *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); + + printk(KERN_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? */ +} + +/*********************************************************************** + * + * 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, +}; + +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) +{ + u32 lo, hi; + + rdmsr(MSR_VIA_RNG, lo, hi); + lo &= ~VIA_RNG_ENABLE; + wrmsr(MSR_VIA_RNG, lo, hi); +} + + +/*********************************************************************** + * + * /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 *buf, size_t size, + loff_t * offp) +{ + static spinlock_t rng_lock = SPIN_LOCK_UNLOCKED; + 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()) + { + 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; +} + + + +/* + * 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 RNGs */ + while ((pdev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, pdev)) != NULL) { + ent = pci_match_device (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; + + 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); + + if (rng_ops->cleanup) + rng_ops->cleanup(); + + DPRINTK ("EXIT\n"); +} + + +module_init (rng_init); +module_exit (rng_cleanup);