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kernel-fxtec-pro1x/drivers/char/hw_random/intel-rng.c
Michael Buesch 56fb5fe9f1 [PATCH] Fix HWRNG built-in initcalls priority 
This changes all HWRNG driver initcalls to module_init().  We must probe
the RNGs after the major kernel subsystems are already up and running (like
PCI).

This fixes Bug 7730.
http://bugzilla.kernel.org/show_bug.cgi?id=7730

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-11 18:18:21 -08:00

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/*
* 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 <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>
*
* 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
/*
* LPC bridge PCI config space registers
*/
#define FWH_DEC_EN1_REG_OLD 0xe3
#define FWH_DEC_EN1_REG_NEW 0xd9 /* high byte of 16-bit register */
#define FWH_F8_EN_MASK 0x80
#define BIOS_CNTL_REG_OLD 0x4e
#define BIOS_CNTL_REG_NEW 0xdc
#define BIOS_CNTL_WRITE_ENABLE_MASK 0x01
#define BIOS_CNTL_LOCK_ENABLE_MASK 0x02
/*
* Magic address at which Intel Firmware Hubs get accessed
*/
#define INTEL_FWH_ADDR 0xffff0000
#define INTEL_FWH_ADDR_LEN 2
/*
* Intel Firmware Hub command codes (write to any address inside the device)
*/
#define INTEL_FWH_RESET_CMD 0xff /* aka READ_ARRAY */
#define INTEL_FWH_READ_ID_CMD 0x90
/*
* Intel Firmware Hub Read ID command result addresses
*/
#define INTEL_FWH_MANUFACTURER_CODE_ADDRESS 0x000000
#define INTEL_FWH_DEVICE_CODE_ADDRESS 0x000001
/*
* Intel Firmware Hub Read ID command result values
*/
#define INTEL_FWH_MANUFACTURER_CODE 0x89
#define INTEL_FWH_DEVICE_CODE_8M 0xac
#define INTEL_FWH_DEVICE_CODE_4M 0xad
/*
* 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 const struct pci_device_id pci_tbl[] = {
/* AA
{ 0x8086, 0x2418, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */
{ 0x8086, 0x2410, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* AA */
/* AB
{ 0x8086, 0x2428, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */
{ 0x8086, 0x2420, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* AB */
/* ??
{ 0x8086, 0x2430, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */
/* BAM, CAM, DBM, FBM, GxM
{ 0x8086, 0x2448, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */
{ 0x8086, 0x244c, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* BAM */
{ 0x8086, 0x248c, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* CAM */
{ 0x8086, 0x24cc, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* DBM */
{ 0x8086, 0x2641, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* FBM */
{ 0x8086, 0x27b9, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* GxM */
{ 0x8086, 0x27bd, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* GxM DH */
/* BA, CA, DB, Ex, 6300, Fx, 631x/632x, Gx
{ 0x8086, 0x244e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */
{ 0x8086, 0x2440, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* BA */
{ 0x8086, 0x2480, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* CA */
{ 0x8086, 0x24c0, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* DB */
{ 0x8086, 0x24d0, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* Ex */
{ 0x8086, 0x25a1, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 6300 */
{ 0x8086, 0x2640, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* Fx */
{ 0x8086, 0x2670, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x2671, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x2672, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x2673, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x2674, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x2675, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x2676, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x2677, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x2678, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x2679, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x267a, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x267b, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x267c, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x267d, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x267e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x267f, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* 631x/632x */
{ 0x8086, 0x27b8, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* Gx */
/* E
{ 0x8086, 0x245e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, */
{ 0x8086, 0x2450, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, /* E */
{ 0, }, /* terminate list */
};
MODULE_DEVICE_TABLE(pci, pci_tbl);
static __initdata int no_fwh_detect;
module_param(no_fwh_detect, int, 0);
MODULE_PARM_DESC(no_fwh_detect, "Skip FWH detection:\n"
" positive value - skip if FWH space locked read-only\n"
" negative value - skip always");
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,
};
#ifdef CONFIG_SMP
static char __initdata waitflag;
static void __init intel_init_wait(void *unused)
{
while (waitflag)
cpu_relax();
}
#endif
static int __init mod_init(void)
{
int err = -ENODEV;
unsigned i;
struct pci_dev *dev = NULL;
void __iomem *mem;
unsigned long flags;
u8 bios_cntl_off, fwh_dec_en1_off;
u8 bios_cntl_val = 0xff, fwh_dec_en1_val = 0xff;
u8 hw_status, mfc, dvc;
for (i = 0; !dev && pci_tbl[i].vendor; ++i)
dev = pci_get_device(pci_tbl[i].vendor, pci_tbl[i].device, NULL);
if (!dev)
goto out; /* Device not found. */
if (no_fwh_detect < 0) {
pci_dev_put(dev);
goto fwh_done;
}
/* Check for Intel 82802 */
if (dev->device < 0x2640) {
fwh_dec_en1_off = FWH_DEC_EN1_REG_OLD;
bios_cntl_off = BIOS_CNTL_REG_OLD;
} else {
fwh_dec_en1_off = FWH_DEC_EN1_REG_NEW;
bios_cntl_off = BIOS_CNTL_REG_NEW;
}
pci_read_config_byte(dev, fwh_dec_en1_off, &fwh_dec_en1_val);
pci_read_config_byte(dev, bios_cntl_off, &bios_cntl_val);
if ((bios_cntl_val &
(BIOS_CNTL_LOCK_ENABLE_MASK|BIOS_CNTL_WRITE_ENABLE_MASK))
== BIOS_CNTL_LOCK_ENABLE_MASK) {
static __initdata /*const*/ char warning[] =
KERN_WARNING PFX "Firmware space is locked read-only. If you can't or\n"
KERN_WARNING PFX "don't want to disable this in firmware setup, and if\n"
KERN_WARNING PFX "you are certain that your system has a functional\n"
KERN_WARNING PFX "RNG, try using the 'no_fwh_detect' option.\n";
pci_dev_put(dev);
if (no_fwh_detect)
goto fwh_done;
printk(warning);
err = -EBUSY;
goto out;
}
mem = ioremap_nocache(INTEL_FWH_ADDR, INTEL_FWH_ADDR_LEN);
if (mem == NULL) {
pci_dev_put(dev);
err = -EBUSY;
goto out;
}
/*
* Since the BIOS code/data is going to disappear from its normal
* location with the Read ID command, all activity on the system
* must be stopped until the state is back to normal.
*/
#ifdef CONFIG_SMP
set_mb(waitflag, 1);
if (smp_call_function(intel_init_wait, NULL, 1, 0) != 0) {
set_mb(waitflag, 0);
pci_dev_put(dev);
printk(KERN_ERR PFX "cannot run on all processors\n");
err = -EAGAIN;
goto err_unmap;
}
#endif
local_irq_save(flags);
if (!(fwh_dec_en1_val & FWH_F8_EN_MASK))
pci_write_config_byte(dev,
fwh_dec_en1_off,
fwh_dec_en1_val | FWH_F8_EN_MASK);
if (!(bios_cntl_val & BIOS_CNTL_WRITE_ENABLE_MASK))
pci_write_config_byte(dev,
bios_cntl_off,
bios_cntl_val | BIOS_CNTL_WRITE_ENABLE_MASK);
writeb(INTEL_FWH_RESET_CMD, mem);
writeb(INTEL_FWH_READ_ID_CMD, mem);
mfc = readb(mem + INTEL_FWH_MANUFACTURER_CODE_ADDRESS);
dvc = readb(mem + INTEL_FWH_DEVICE_CODE_ADDRESS);
writeb(INTEL_FWH_RESET_CMD, mem);
if (!(bios_cntl_val &
(BIOS_CNTL_LOCK_ENABLE_MASK|BIOS_CNTL_WRITE_ENABLE_MASK)))
pci_write_config_byte(dev, bios_cntl_off, bios_cntl_val);
if (!(fwh_dec_en1_val & FWH_F8_EN_MASK))
pci_write_config_byte(dev, fwh_dec_en1_off, fwh_dec_en1_val);
local_irq_restore(flags);
#ifdef CONFIG_SMP
/* Tell other CPUs to resume. */
set_mb(waitflag, 0);
#endif
iounmap(mem);
pci_dev_put(dev);
if (mfc != INTEL_FWH_MANUFACTURER_CODE ||
(dvc != INTEL_FWH_DEVICE_CODE_8M &&
dvc != INTEL_FWH_DEVICE_CODE_4M)) {
printk(KERN_ERR PFX "FWH not detected\n");
err = -ENODEV;
goto out;
}
fwh_done:
err = -ENOMEM;
mem = ioremap(INTEL_RNG_ADDR, INTEL_RNG_ADDR_LEN);
if (!mem)
goto out;
intel_rng.priv = (unsigned long)mem;
/* Check for Random Number Generator */
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 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);
}
module_init(mod_init);
module_exit(mod_exit);
MODULE_DESCRIPTION("H/W RNG driver for Intel chipsets");
MODULE_LICENSE("GPL");
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