Attached is a patch against 2.3.41.2 which adds support for the Intel
i8xx chipset RNG. This driver is quite simple -- it uses a kernel timer
to add a byte of entropy every N jiffies, currently N=HZ/2.
In order to do so, it was necessary to export a single function from
random.c. In addition, I took this opportunity to clean up the random.c
EXPORTs.
Sorry Matt, it was faster to write a new driver from scratch to
illustrate this approach to the RNG implementation. :)
Comments welcome. I don't have any i810 hardware, so please test! It
looks ok to me, and the RNG hardware is pretty damn simple.
Jeff
-- Jeff Garzik | Andre the Giant has a posse. Building 1024 | MandrakeSoft, Inc. |
diff -urN /spare/vanilla/linux-2.3.41-pre2/include/linux/random.h linux/include/linux/random.h --- /spare/vanilla/linux-2.3.41-pre2/include/linux/random.h Thu Jan 6 13:14:36 2000 +++ linux/include/linux/random.h Mon Jan 24 14:56:51 2000 @@ -46,6 +46,8 @@ extern void rand_initialize_irq(int irq); extern void rand_initialize_blkdev(int irq, int mode); +extern void batch_entropy_store(u32 a, u32 b, int num); + extern void add_keyboard_randomness(unsigned char scancode); extern void add_mouse_randomness(__u32 mouse_data); extern void add_interrupt_randomness(int irq); diff -urN /spare/vanilla/linux-2.3.41-pre2/drivers/char/Config.in linux/drivers/char/Config.in --- /spare/vanilla/linux-2.3.41-pre2/drivers/char/Config.in Sun Jan 23 19:25:52 2000 +++ linux/drivers/char/Config.in Mon Jan 24 14:56:49 2000 @@ -125,6 +125,7 @@ if [ "$CONFIG_ALPHA_BOOK1" = "y" ]; then bool 'Tadpole ANA H8 Support' CONFIG_H8 fi +dep_tristate 'Intel i8xx Random Number Generator (RNG) support (EXPERIMENTAL)' CONFIG_I810_RNG $CONFIG_EXPERIMENTAL mainmenu_option next_comment comment 'Video For Linux' diff -urN /spare/vanilla/linux-2.3.41-pre2/drivers/char/Makefile linux/drivers/char/Makefile --- /spare/vanilla/linux-2.3.41-pre2/drivers/char/Makefile Sun Jan 23 19:25:52 2000 +++ linux/drivers/char/Makefile Mon Jan 24 14:56:50 2000 @@ -20,8 +20,8 @@ O_TARGET := char.o M_OBJS := -O_OBJS := tty_io.o n_tty.o tty_ioctl.o mem.o random.o raw.o -OX_OBJS := pty.o misc.o +O_OBJS := tty_io.o n_tty.o tty_ioctl.o mem.o raw.o +OX_OBJS := pty.o misc.o random.o KEYMAP =defkeymap.o KEYBD =pc_keyb.o @@ -380,6 +380,14 @@ ifeq ($(CONFIG_PPC),) M_OBJS += nvram.o endif + endif +endif + +ifeq ($(CONFIG_I810_RNG),y) +O_OBJS += i810_rng.o +else + ifeq ($(CONFIG_I810_RNG),m) + M_OBJS += i810_rng.o endif endif diff -urN /spare/vanilla/linux-2.3.41-pre2/drivers/char/i810_rng.c linux/drivers/char/i810_rng.c --- /spare/vanilla/linux-2.3.41-pre2/drivers/char/i810_rng.c Wed Dec 31 19:00:00 1969 +++ linux/drivers/char/i810_rng.c Mon Jan 24 15:06:16 2000 @@ -0,0 +1,422 @@ +/* + + Hardware driver for Intel i810 Random Number Generator (RNG) + Copyright 2000 Jeff Garzik <jgarzik@mandrakesoft.com> + + 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 msottek@quiknet.com + + ---------------------------------------------------------- + + This software may be used and distributed according to the terms + of the GNU Public License, incorporated herein by reference. + + ---------------------------------------------------------- + + 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. + + */ + + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/pci.h> +#include <linux/spinlock.h> +#include <linux/random.h> +#include <linux/sysctl.h> + +#include <asm/io.h> + + +/* + * core module and version information + */ +#define RNG_VERSION "0.0.1" +#define RNG_MODULE_NAME "i810_rng" +#define RNG_DRIVER_NAME RNG_MODULE_NAME " hardware driver " RNG_VERSION +#define PFX RNG_MODULE_NAME ": " + + +/* + * debugging macros + */ +#undef RNG_DEBUG /* define to 1 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 0 /* define to 1 to disable lightweight runtime checks */ +#if 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 + + +/* + * misc helper macros + */ +#define arraysize(x) (sizeof(x)/sizeof(*(x))) + + +/* + * RNG registers + */ +#define RNG_HW_STATUS 0 +#define RNG_PRESENT 0x40 +#define RNG_ENABLED 0x01 +#define RNG_STATUS 1 +#define RNG_DATA_PRESENT 0x01 +#define RNG_DATA 2 + +#define RNG_ADDR 0xFFBC015F +#define RNG_ADDR_LEN 3 + + +/* + * Frequency that data is added to kernel entropy pool + */ +#define RNG_TIMER_LEN (HZ >> 1) + + +/* + * various RNG status variables. they are globals + * as we only support a single RNG device + */ +static int rng_allocated = 0; +static int rng_enabled = 0; +static int rng_enabled_sysctl; +void *rng_mem = NULL; +spinlock_t rng_lock = SPIN_LOCK_UNLOCKED; +static struct timer_list rng_timer; + + +/* + * inlined helper functions for RNG registers + */ +static inline u8 rng_hwstatus (void) +{ + assert (rng_mem != NULL); + return readb (rng_mem + RNG_HW_STATUS); +} + + +static inline void rng_hwstatus_set (u8 hw_status) +{ + assert (rng_mem != NULL); + writeb (hw_status, rng_mem + RNG_HW_STATUS); +} + + +static inline int rng_data_present (void) +{ + assert (rng_mem != NULL); + assert (rng_enabled == 1); + + return (readb (rng_mem + RNG_STATUS) & RNG_DATA_PRESENT) ? 1 : 0; +} + + +static inline int rng_data_read (void) +{ + assert (rng_mem != NULL); + assert (rng_enabled == 1); + + return readb (rng_mem + RNG_DATA); +} + + +/* + * rng_timer_ticker - executes every RNG_TIMER_LEN jiffies, + * adds a single byte of entropy + */ +static void rng_timer_tick(unsigned long data) +{ + unsigned long flags; + + del_timer (&rng_timer); + + spin_lock_irqsave (&rng_lock, flags); + + if (rng_data_present ()) { + static int rng_data; + + rng_data = rng_data_read (); + + batch_entropy_store (rng_data, jiffies, + 8 /* # bits entropy added */); + } + + spin_unlock_irqrestore (&rng_lock, flags); + + rng_timer.expires = jiffies + RNG_TIMER_LEN; + add_timer (&rng_timer); +} + + +/* + * rng_enable - enable or disable the RNG and internal timer + */ +static int rng_enable (int enable) +{ + unsigned long flags; + u8 hw_status; + + DPRINTK ("ENTER\n"); + + spin_lock_irqsave (&rng_lock, flags); + + hw_status = rng_hwstatus (); + + if (enable && ((hw_status & RNG_ENABLED) == 0)) { + rng_timer.expires = jiffies + RNG_TIMER_LEN; + add_timer (&rng_timer); + + rng_hwstatus_set (hw_status | RNG_ENABLED); + + MOD_INC_USE_COUNT; + DPRINTK ("RNG enabled\n"); + rng_enabled = 1; + } + + else if (!enable && (hw_status & RNG_ENABLED)) { + del_timer (&rng_timer); + + hw_status &= ~RNG_ENABLED; + rng_hwstatus_set (hw_status); + + MOD_DEC_USE_COUNT; + DPRINTK ("RNG disabled\n"); + rng_enabled = 0; + } + + if (hw_status != rng_hwstatus ()) { + spin_unlock_irqrestore (&rng_lock, flags); + printk (KERN_ERR PFX "Unable to %sable the RNG\n", + enable ? "en" : "dis"); + DPRINTK ("EXIT, returning -EIO\n"); + return -EIO; + } + + spin_unlock_irqrestore (&rng_lock, flags); + + DPRINTK ("EXIT, returning 0\n"); + return 0; +} + + +/* + * rng_handle_sysctl - handle a read or write of our sysctl + */ + +int rng_handle_sysctl (ctl_table * table, int write, struct file *filp, + void *buffer, size_t * lenp) +{ + unsigned long flags; + int enabled_save, rc; + + DPRINTK ("ENTER\n"); + + spin_lock_irqsave (&rng_lock, flags); + rng_enabled_sysctl = enabled_save = rng_enabled; + spin_unlock_irqrestore (&rng_lock, flags); + + rc = proc_dointvec (table, write, filp, buffer, lenp); + if (rc) + return rc; + + if (enabled_save != rng_enabled_sysctl) + rng_enable (rng_enabled_sysctl); + + DPRINTK ("EXIT, returning 0\n"); + return 0; +} + + +/* + * rng_sysctl - add or remove the rng sysctl + */ +static void rng_sysctl (int add) +{ +#define FS_NTFS 1 + /* Definition of the sysctl */ + static ctl_table rng_sysctls[] = { + {FS_NTFS, /* ID */ + RNG_MODULE_NAME, /* name in /proc */ + &rng_enabled_sysctl, + sizeof (rng_enabled_sysctl), /* data ptr, data size */ + 0644, /* mode */ + 0, /* child */ + rng_handle_sysctl, /* proc handler */ + 0, /* strategy */ + 0, /* proc control block */ + 0, 0} + , /* extra */ + {0} + }; + + /* Define the parent file : /proc/sys/dev */ + static ctl_table sysctls_root[] = { + {CTL_DEV, + "dev", + NULL, 0, + 0555, + rng_sysctls}, + {0} + }; + static struct ctl_table_header *sysctls_root_header = NULL; + + if (add) { + if (!sysctls_root_header) + sysctls_root_header = register_sysctl_table (sysctls_root, 0); + } else if (sysctls_root_header) { + unregister_sysctl_table (sysctls_root_header); + sysctls_root_header = NULL; + } +} + + +/* + * rng_probe - look for and attempt to init a single RNG + */ +static int __init rng_probe (struct pci_dev *dev, + const struct pci_device_id *id) +{ + int rc; + u8 input; + + DPRINTK ("ENTER\n"); + + if (rng_allocated) { + printk (KERN_ERR PFX "this driver only supports one RNG\n"); + DPRINTK ("EXIT, returning -EBUSY\n"); + return -EBUSY; + } + + if (!request_mem_region (RNG_ADDR, RNG_ADDR_LEN, RNG_MODULE_NAME)) { + printk (KERN_ERR PFX "RNG Memory region not available\n"); + DPRINTK ("EXIT, returning -EBUSY\n"); + return -EBUSY; + } + + /* Check for Intel 82802 */ + rng_mem = ioremap (RNG_ADDR, RNG_ADDR_LEN); + if (rng_mem == NULL) { + printk (KERN_ERR PFX "cannot ioremap RNG Memory\n"); + DPRINTK ("EXIT, returning -EBUSY\n"); + rc = -EBUSY; + goto err_out; + } + + input = rng_hwstatus (); + if ((input & RNG_PRESENT) == 0) { + printk (KERN_ERR PFX "RNG not detected\n"); + DPRINTK ("EXIT, returning -ENODEV\n"); + rc = -ENODEV; + goto err_out; + } + + rc = rng_enable (1); + if (rc) { + DPRINTK ("EXIT, returning %d\n", rc); + goto err_out; + } + + rng_allocated = 1; + init_timer (&rng_timer); + rng_timer.function = rng_timer_tick; + + rng_sysctl (1); + + DPRINTK ("EXIT, returning 0\n"); + return 0; + +err_out: + if (rng_mem) + iounmap (rng_mem); + release_mem_region (RNG_ADDR, RNG_ADDR_LEN); + return rc; +} + + +/* + * Data for PCI driver interface + */ +const static struct pci_device_id rng_pci_tbl[] __initdata = { + { 0x8086, 0x2418, PCI_ANY_ID, PCI_ANY_ID, }, + { 0x8086, 0x2428, PCI_ANY_ID, PCI_ANY_ID, }, + { 0, }, +}; +MODULE_DEVICE_TABLE (pci, rng_pci_tbl); + + +static struct pci_driver rng_driver = { + name: RNG_MODULE_NAME, + id_table: rng_pci_tbl, + probe: rng_probe, +}; + + +/* + * rng_init - initialize RNG module + */ +static int __init rng_init (void) +{ + DPRINTK ("ENTER\n"); + + if (pci_register_driver (&rng_driver) < 1) { + DPRINTK ("EXIT, returning -ENODEV\n"); + return -ENODEV; + } + + 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"); + + rng_sysctl (0); + rng_enable (0); + pci_unregister_driver (&rng_driver); + release_mem_region (RNG_ADDR, RNG_ADDR_LEN); + + DPRINTK ("EXIT\n"); +} + + +module_init (rng_init); +module_exit (rng_cleanup); diff -urN /spare/vanilla/linux-2.3.41-pre2/drivers/char/random.c linux/drivers/char/random.c --- /spare/vanilla/linux-2.3.41-pre2/drivers/char/random.c Thu Jan 6 13:14:36 2000 +++ linux/drivers/char/random.c Mon Jan 24 14:56:50 2000 @@ -235,6 +235,7 @@ #include <linux/utsname.h> #include <linux/config.h> +#include <linux/module.h> #include <linux/kernel.h> #include <linux/major.h> #include <linux/string.h> @@ -626,7 +627,7 @@ return 0; } -static void batch_entropy_store(__u32 a, __u32 b, int num) +void batch_entropy_store(u32 a, u32 b, int num) { int new; @@ -2238,3 +2239,12 @@ return (cookie - tmp[17]) & COOKIEMASK; /* Leaving the data behind */ } #endif + + + +EXPORT_SYMBOL(add_keyboard_randomness); +EXPORT_SYMBOL(add_mouse_randomness); +EXPORT_SYMBOL(add_interrupt_randomness); +EXPORT_SYMBOL(add_blkdev_randomness); +EXPORT_SYMBOL(batch_entropy_store); + diff -urN /spare/vanilla/linux-2.3.41-pre2/kernel/ksyms.c linux/kernel/ksyms.c --- /spare/vanilla/linux-2.3.41-pre2/kernel/ksyms.c Tue Jan 18 21:54:21 2000 +++ linux/kernel/ksyms.c Mon Jan 24 14:56:51 2000 @@ -183,7 +183,6 @@ EXPORT_SYMBOL(ll_rw_block); EXPORT_SYMBOL(__wait_on_buffer); EXPORT_SYMBOL(___wait_on_page); -EXPORT_SYMBOL(add_blkdev_randomness); EXPORT_SYMBOL(block_read_full_page); EXPORT_SYMBOL(block_write_full_page); EXPORT_SYMBOL(block_write_partial_page); @@ -436,7 +435,6 @@ EXPORT_SYMBOL(fs_overflowgid); /* all busmice */ -EXPORT_SYMBOL(add_mouse_randomness); EXPORT_SYMBOL(fasync_helper); #ifdef CONFIG_BLK_DEV_MD
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This archive was generated by hypermail 2b29 : Mon Jan 31 2000 - 21:00:13 EST