On Fri, May 12, 2006 at 12:35:25PM +0200, Michael Buesch wrote: > Index: hwrng/drivers/char/hw_random/intel-rng.c > =================================================================== > --- /dev/null 1970-01-01 00:00:00.000000000 +0000 > +++ hwrng/drivers/char/hw_random/intel-rng.c 2006-05-08 00:11:35.000000000 +0200 > @@ -0,0 +1,198 @@ > +/* > + * RNG driver for Intel 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 <[email protected]> > + * > + * derived from > + * > + * Hardware driver for the AMD 768 Random Number Generator (RNG) > + * (c) Copyright 2001 Red Hat Inc <[email protected]> > + * > + * derived from > + * > + * Hardware driver for Intel i810 Random Number Generator (RNG) > + * Copyright 2000,2001 Jeff Garzik <[email protected]> > + * Copyright 2000,2001 Philipp Rumpf <[email protected]> > + * > + * 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/pci.h> > +#include <linux/hw_random.h> > +#include <asm/io.h> > + > + > +#define PFX KBUILD_MODNAME ": " > + > +/* > + * RNG registers > + */ > +#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 > + > +/* > + * 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 pci_tbl[] = { Should be const. > + { 0x8086, 0x2418, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, > + { 0x8086, 0x2428, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, > + { 0x8086, 0x2430, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, > + { 0x8086, 0x2448, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, > + { 0x8086, 0x244e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, > + { 0x8086, 0x245e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, > + { 0, }, /* terminate list */ > +}; > +MODULE_DEVICE_TABLE(pci, pci_tbl); > + > + > +static inline u8 hwstatus_get(void __iomem *mem) > +{ > + return readb(mem + INTEL_RNG_HW_STATUS); > +} > + > +static inline u8 hwstatus_set(void __iomem *mem, > + u8 hw_status) > +{ > + writeb(hw_status, mem + INTEL_RNG_HW_STATUS); > + return hwstatus_get(mem); > +} > + > +static int intel_rng_data_present(struct hwrng *rng) > +{ > + void __iomem *mem = (void __iomem *)rng->priv; > + > + return !!(readb(mem + INTEL_RNG_STATUS) & INTEL_RNG_DATA_PRESENT); > +} > + > +static int intel_rng_data_read(struct hwrng *rng, u32 *data) > +{ > + void __iomem *mem = (void __iomem *)rng->priv; > + > + *data = readb(mem + INTEL_RNG_DATA); > + > + return 1; > +} > + > +static int intel_rng_init(struct hwrng *rng) > +{ > + void __iomem *mem = (void __iomem *)rng->priv; > + u8 hw_status; > + int err = -EIO; > + > + hw_status = hwstatus_get(mem); > + /* turn RNG h/w on, if it's off */ > + if ((hw_status & INTEL_RNG_ENABLED) == 0) > + hw_status = hwstatus_set(mem, hw_status | INTEL_RNG_ENABLED); > + if ((hw_status & INTEL_RNG_ENABLED) == 0) { > + printk(KERN_ERR PFX "cannot enable RNG, aborting\n"); > + goto out; > + } > + err = 0; > +out: > + return err; > +} > + > +static void intel_rng_cleanup(struct hwrng *rng) > +{ > + void __iomem *mem = (void __iomem *)rng->priv; > + u8 hw_status; > + > + hw_status = hwstatus_get(mem); > + if (hw_status & INTEL_RNG_ENABLED) > + hwstatus_set(mem, hw_status & ~INTEL_RNG_ENABLED); > + else > + printk(KERN_WARNING PFX "unusual: RNG already disabled\n"); > +} > + > + > +static struct hwrng intel_rng = { > + .name = "intel", > + .init = intel_rng_init, > + .cleanup = intel_rng_cleanup, > + .data_present = intel_rng_data_present, > + .data_read = intel_rng_data_read, > +}; > + > + > +static int __init mod_init(void) > +{ > + int err = -ENODEV; > + struct pci_dev *pdev = NULL; > + const struct pci_device_id *ent; > + void __iomem *mem; > + u8 hw_status; > + > + for_each_pci_dev(pdev) { > + ent = pci_match_id(pci_tbl, pdev); > + if (ent) > + goto found; > + } > + /* Device not found. */ > + goto out; if (!pci_dev_present(pci_tbl)) goto out; > + > +found: > + err = -ENOMEM; > + mem = ioremap(INTEL_RNG_ADDR, INTEL_RNG_ADDR_LEN); > + if (!mem) > + goto out; > + intel_rng.priv = (unsigned long)mem; > + > + /* Check for Intel 82802 */ > + err = -ENODEV; > + hw_status = hwstatus_get(mem); > + if ((hw_status & INTEL_RNG_PRESENT) == 0) > + goto err_unmap; > + > + printk(KERN_INFO "Intel 82802 RNG detected\n"); > + err = hwrng_register(&intel_rng); > + if (err) { > + printk(KERN_ERR PFX "RNG registering failed (%d)\n", > + err); > + goto out; goto err_unmap; > + } > +out: > + return err; > + > +err_unmap: > + iounmap(mem); > + goto out; > +} > + > +static void __exit mod_exit(void) > +{ > + void __iomem *mem = (void __iomem *)intel_rng.priv; > + > + hwrng_unregister(&intel_rng); > + iounmap(mem); > +} > + > +subsys_initcall(mod_init); > +module_exit(mod_exit); > + > +MODULE_AUTHOR("The Linux Kernel team"); > +MODULE_DESCRIPTION("H/W RNG driver for Intel chipsets"); > +MODULE_LICENSE("GPL"); > > --
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