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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2008-2009 coresystems GmbH
*
* 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; version 2 of
* the License.
*
* 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., 51 Franklin St, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include <arch/io.h>
#include <arch/romcc_io.h>
#include <console/console.h>
#include <cpu/x86/cache.h>
#include <cpu/x86/smm.h>
#if !CONFIG_SMM_TSEG /* TSEG handler locks in assembly */
typedef enum { SMI_LOCKED, SMI_UNLOCKED } smi_semaphore;
/* SMI multiprocessing semaphore */
static volatile smi_semaphore smi_handler_status __attribute__ ((aligned (4))) = SMI_UNLOCKED;
static int smi_obtain_lock(void)
{
u8 ret = SMI_LOCKED;
asm volatile (
"movb %2, %%al\n"
"xchgb %%al, %1\n"
"movb %%al, %0\n"
: "=g" (ret), "=m" (smi_handler_status)
: "g" (SMI_LOCKED)
: "eax"
);
return (ret == SMI_UNLOCKED);
}
void smi_release_lock(void)
{
asm volatile (
"movb %1, %%al\n"
"xchgb %%al, %0\n"
: "=m" (smi_handler_status)
: "g" (SMI_UNLOCKED)
: "eax"
);
}
#endif
#define LAPIC_ID 0xfee00020
static inline __attribute__((always_inline)) unsigned long nodeid(void)
{
return (*((volatile unsigned long *)(LAPIC_ID)) >> 24);
}
void io_trap_handler(int smif)
{
/* If a handler function handled a given IO trap, it
* shall return a non-zero value
*/
printk(BIOS_DEBUG, "SMI function trap 0x%x: ", smif);
if (southbridge_io_trap_handler(smif))
return;
if (mainboard_io_trap_handler(smif))
return;
printk(BIOS_DEBUG, "Unknown function\n");
}
/**
* @brief Set the EOS bit
*/
static void smi_set_eos(void)
{
southbridge_smi_set_eos();
}
static u32 pci_orig;
/**
* @brief Backup PCI address to make sure we do not mess up the OS
*/
static void smi_backup_pci_address(void)
{
pci_orig = inl(0xcf8);
}
/**
* @brief Restore PCI address previously backed up
*/
static void smi_restore_pci_address(void)
{
outl(pci_orig, 0xcf8);
}
/**
* @brief Interrupt handler for SMI#
*
* @param smm_revision revision of the smm state save map
*/
void smi_handler(u32 smm_revision)
{
unsigned int node;
smm_state_save_area_t state_save;
#if !CONFIG_SMM_TSEG
/* Are we ok to execute the handler? */
if (!smi_obtain_lock()) {
/* For security reasons we don't release the other CPUs
* until the CPU with the lock is actually done
*/
while (smi_handler_status == SMI_LOCKED) {
asm volatile (
".byte 0xf3, 0x90\n" /* hint a CPU we are in spinlock (PAUSE instruction, REP NOP) */
);
}
return;
}
#endif
smi_backup_pci_address();
node=nodeid();
console_init();
printk(BIOS_SPEW, "\nSMI# #%d\n", node);
switch (smm_revision) {
case 0x00030002:
case 0x00030007:
state_save.type = LEGACY;
state_save.legacy_state_save = (legacy_smm_state_save_area_t *)
(0xa8000 + 0x7e00 - (node * 0x400));
break;
case 0x00030100:
case 0x00030101: /* SandyBridge */
state_save.type = EM64T;
state_save.em64t_state_save = (em64t_smm_state_save_area_t *)
(0xa8000 + 0x7d00 - (node * 0x400));
break;
case 0x00030064:
state_save.type = AMD64;
state_save.amd64_state_save = (amd64_smm_state_save_area_t *)
(0xa8000 + 0x7e00 - (node * 0x400));
break;
default:
printk(BIOS_DEBUG, "smm_revision: 0x%08x\n", smm_revision);
printk(BIOS_DEBUG, "SMI# not supported on your CPU\n");
/* Don't release lock, so no further SMI will happen,
* if we don't handle it anyways.
*/
return;
}
/* Call chipset specific SMI handlers. */
if (cpu_smi_handler)
cpu_smi_handler(node, &state_save);
if (northbridge_smi_handler)
northbridge_smi_handler(node, &state_save);
if (southbridge_smi_handler)
southbridge_smi_handler(node, &state_save);
smi_restore_pci_address();
#if !CONFIG_SMM_TSEG
smi_release_lock();
#endif
/* De-assert SMI# signal to allow another SMI */
smi_set_eos();
}
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