diff options
Diffstat (limited to 'drivers/char/hw_random.c')
| -rw-r--r-- | drivers/char/hw_random.c | 698 |
1 files changed, 0 insertions, 698 deletions
diff --git a/drivers/char/hw_random.c b/drivers/char/hw_random.c deleted file mode 100644 index 29dc87e5902..00000000000 --- a/drivers/char/hw_random.c +++ /dev/null @@ -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); |