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/* SPDX-License-Identifier: GPL-2.0-only */
#include <arch/io.h>
#include <console/console.h>
#include <commonlib/region.h>
#include <cpu/x86/smm.h>
#include <cpu/x86/smi_deprecated.h>
#include <cpu/amd/amd64_save_state.h>
#include <cpu/intel/em64t100_save_state.h>
#include <cpu/intel/em64t101_save_state.h>
#include <cpu/x86/legacy_save_state.h>
#if CONFIG(SPI_FLASH_SMM)
#include <spi-generic.h>
#endif
static int do_driver_init = 1;
typedef enum { SMI_LOCKED, SMI_UNLOCKED } smi_semaphore;
/* SMI multiprocessing semaphore */
static __attribute__((aligned(4))) volatile smi_semaphore smi_handler_status
= 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);
}
static void smi_release_lock(void)
{
asm volatile (
"movb %1, %%al\n"
"xchgb %%al, %0\n"
: "=m" (smi_handler_status)
: "g" (SMI_UNLOCKED)
: "eax"
);
}
#define LAPIC_ID 0xfee00020
static __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);
}
static inline void *smm_save_state(uintptr_t base, int arch_offset, int node)
{
base += SMM_SAVE_STATE_BEGIN(arch_offset) - (node * 0x400);
return (void *)base;
}
/* This returns the SMM revision from the savestate of CPU0,
which is assumed to be the same for all CPU's. See the memory
map in smmhandler.S */
uint32_t smm_revision(void)
{
return *(uint32_t *)(SMM_BASE + SMM_ENTRY_OFFSET * 2 - SMM_REVISION_OFFSET_FROM_TOP);
}
void *smm_get_save_state(int cpu)
{
switch (smm_revision()) {
case 0x00030002:
case 0x00030007:
return smm_save_state(SMM_BASE, SMM_LEGACY_ARCH_OFFSET, cpu);
case 0x00030100:
return smm_save_state(SMM_BASE, SMM_EM64T100_ARCH_OFFSET, cpu);
case 0x00030101: /* SandyBridge, IvyBridge, and Haswell */
return smm_save_state(SMM_BASE, SMM_EM64T101_ARCH_OFFSET, cpu);
case 0x00020064:
case 0x00030064:
return smm_save_state(SMM_BASE, SMM_AMD64_ARCH_OFFSET, cpu);
}
return NULL;
}
bool smm_region_overlaps_handler(const struct region *r)
{
const struct region r_smm = {SMM_BASE, SMM_DEFAULT_SIZE};
return region_overlap(&r_smm, r);
}
/**
* @brief Interrupt handler for SMI#
*
* @param smm_revision revision of the smm state save map
*/
void smi_handler(void)
{
unsigned int node;
/* 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;
}
smi_backup_pci_address();
node = nodeid();
console_init();
printk(BIOS_SPEW, "\nSMI# #%d\n", node);
/* Use smm_get_save_state() to see if the smm revision is supported */
if (smm_get_save_state(node) == NULL) {
printk(BIOS_WARNING, "smm_revision: 0x%08x\n", smm_revision());
printk(BIOS_WARNING, "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;
}
/* Allow drivers to initialize variables in SMM context. */
if (do_driver_init) {
#if CONFIG(SPI_FLASH_SMM)
spi_init();
#endif
do_driver_init = 0;
}
/* Call chipset specific SMI handlers. */
southbridge_smi_handler();
smi_restore_pci_address();
smi_release_lock();
/* De-assert SMI# signal to allow another SMI */
smi_set_eos();
}
/* Provide a default implementation for all weak handlers so that relocation
* entries in the modules make sense. Without default implementations the
* weak relocations w/o a symbol have a 0 address which is where the modules
* are linked at. */
int __weak mainboard_io_trap_handler(int smif) { return 0; }
void __weak southbridge_smi_handler(void) {}
void __weak mainboard_smi_gpi(u32 gpi_sts) {}
int __weak mainboard_smi_apmc(u8 data) { return 0; }
void __weak mainboard_smi_sleep(u8 slp_typ) {}
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