/**
|
* SMI workaround for x86.
|
*
|
* Cut/Pasted from Vitor Angelo "smi" module.
|
* Adapted by Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>.
|
*
|
* This program is free software; you can redistribute it and/or modify
|
* it under the terms of the GNU General Public License as published by
|
* the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
|
* USA; either version 2 of the License, or (at your option) any later
|
* version.
|
*
|
* This program is distributed in the hope that it will be useful,
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
* GNU General Public License for more details.
|
*
|
* You should have received a copy of the GNU General Public License
|
* along with this program; if not, write to the Free Software
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
*/
|
|
#include <linux/kernel.h>
|
#include <linux/module.h>
|
#include <linux/version.h>
|
#include <linux/ctype.h>
|
#include <linux/pci.h>
|
#include <linux/pci_ids.h>
|
#include <linux/reboot.h>
|
#include <cobalt/kernel/assert.h>
|
#include <asm-generic/xenomai/pci_ids.h>
|
#include <asm/xenomai/machine.h>
|
|
#define DEVFN 0xf8 /* device 31, function 0 */
|
|
#define PMBASE_B0 0x40
|
#define PMBASE_B1 0x41
|
|
#define SMI_CTRL_ADDR 0x30
|
|
static int smi_state;
|
static char smi_state_arg[16] = "detect";
|
module_param_string(smi, smi_state_arg, sizeof(smi_state_arg), 0444);
|
|
static unsigned int smi_masked_bits = 1; /* Global disable bit */
|
module_param_named(smi_mask, smi_masked_bits, int, 0400);
|
|
static unsigned int smi_saved_bits;
|
static unsigned short smi_en_addr;
|
|
#define mask_bits(v, p) outl(inl(p)&~(v),(p))
|
#define set_bits(v, p) outl(inl(p)|(v), (p))
|
|
static int smi_reboot(struct notifier_block *nb, ulong event, void *buf);
|
|
static struct notifier_block smi_notifier = {
|
.notifier_call = smi_reboot
|
};
|
|
static int smi_reboot(struct notifier_block *nb, ulong event, void *buf)
|
{
|
if (((event == SYS_RESTART) || (event == SYS_HALT) ||
|
(event == SYS_POWER_OFF)) && smi_en_addr)
|
set_bits(smi_saved_bits, smi_en_addr);
|
|
return NOTIFY_DONE;
|
}
|
|
void mach_x86_smi_disable(void)
|
{
|
if (smi_en_addr == 0)
|
return;
|
|
smi_saved_bits = inl(smi_en_addr) & smi_masked_bits;
|
mask_bits(smi_masked_bits, smi_en_addr);
|
|
if (inl(smi_en_addr) & smi_masked_bits)
|
printk(XENO_WARNING "SMI workaround failed!\n");
|
else
|
printk(XENO_INFO "SMI workaround enabled\n");
|
|
register_reboot_notifier(&smi_notifier);
|
}
|
|
void mach_x86_smi_restore(void)
|
{
|
if (smi_en_addr == 0)
|
return;
|
|
printk(XENO_INFO "SMI configuration restored\n");
|
|
set_bits(smi_saved_bits, smi_en_addr);
|
|
unregister_reboot_notifier(&smi_notifier);
|
}
|
|
static unsigned short get_smi_en_addr(struct pci_dev *dev)
|
{
|
u_int8_t byte0, byte1;
|
|
pci_read_config_byte(dev, PMBASE_B0, &byte0);
|
pci_read_config_byte(dev, PMBASE_B1, &byte1);
|
return SMI_CTRL_ADDR + (((byte1 << 1) | (byte0 >> 7)) << 7); // bits 7-15
|
}
|
|
|
static const char *smi_state_labels[] = {
|
"disabled",
|
"detect",
|
"enabled",
|
};
|
|
static void setup_smi_state(void)
|
{
|
static char warn_bad_state[] =
|
XENO_WARNING "invalid SMI state '%s'\n";
|
char *p;
|
int n;
|
|
/* Backward compat with legacy state specifiers. */
|
n = simple_strtol(smi_state_arg, &p, 10);
|
if (*p == '\0') {
|
smi_state = n;
|
return;
|
}
|
|
for (n = 0; n < ARRAY_SIZE(smi_state_labels); n++)
|
if (strcmp(smi_state_labels[n], smi_state_arg) == 0) {
|
smi_state = n - 1;
|
return;
|
}
|
|
printk(warn_bad_state, smi_state_arg);
|
}
|
|
void mach_x86_smi_init(void)
|
{
|
struct pci_dev *dev = NULL;
|
|
setup_smi_state();
|
|
if (smi_state < 0)
|
return;
|
|
/*
|
* Do not use pci_register_driver, pci_enable_device, ...
|
* Just register the used ports.
|
*/
|
dev = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, NULL);
|
if (dev == NULL || dev->bus->number ||
|
dev->devfn != DEVFN || dev->vendor != PCI_VENDOR_ID_INTEL) {
|
pci_dev_put(dev);
|
return;
|
}
|
|
if (smi_state == 0) {
|
printk(XENO_WARNING "SMI-enabled chipset found, but SMI workaround disabled\n"
|
" (see xenomai.smi parameter). You might encounter\n"
|
" high latencies!\n");
|
pci_dev_put(dev);
|
return;
|
}
|
|
printk(XENO_INFO "SMI-enabled chipset found\n");
|
smi_en_addr = get_smi_en_addr(dev);
|
|
pci_dev_put(dev);
|
}
|
