/**
* Normally this function is defined in lapic.h as an always inline function
* that just keeps the CPU in a hlt() loop. This does not work on all CPUs.
* I think all hyperthreading CPUs might need this version, but I could only
* verify this on the Intel Core Duo
*/
void stop_this_cpu(void)
{
int timeout;
unsigned long send_status;
unsigned long id;
id = lapicid();
printk(BIOS_DEBUG, "CPU %ld going down...\n", id);
/* send an LAPIC INIT to myself */
lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(id));
lapic_write_around(LAPIC_ICR, LAPIC_INT_LEVELTRIG |
LAPIC_INT_ASSERT | LAPIC_DM_INIT);
/* wait for the ipi send to finish */
#if DEBUG_HALT_SELF
printk(BIOS_SPEW, "Waiting for send to finish...\n");
#endif
timeout = 0;
do {
#if DEBUG_HALT_SELF
printk(BIOS_SPEW, "+");
#endif
udelay(100);
send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
if (timeout >= 1000) {
#if DEBUG_HALT_SELF
printk(BIOS_ERR, "timed out\n");
#endif
}
mdelay(10);
#if DEBUG_HALT_SELF
printk(BIOS_SPEW, "Deasserting INIT.\n");
#endif
/* Deassert the LAPIC INIT */
lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(id));
lapic_write_around(LAPIC_ICR, LAPIC_INT_LEVELTRIG | LAPIC_DM_INIT);
#if DEBUG_HALT_SELF
printk(BIOS_SPEW, "Waiting for send to finish...\n");
#endif
timeout = 0;
do {
#if DEBUG_HALT_SELF
printk(BIOS_SPEW, "+");
#endif
udelay(100);
send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
if (timeout >= 1000) {
#if DEBUG_HALT_SELF
printk(BIOS_ERR, "timed out\n");
#endif
}
halt();
}
static int start_aps(int ap_count, atomic_t *num_aps)
{
int sipi_vector;
/* Max location is 4KiB below 1MiB */
const int max_vector_loc = ((1 << 20) - (1 << 12)) >> 12;
if (ap_count == 0)
return 0;
/* The vector is sent as a 4k aligned address in one byte */
sipi_vector = AP_DEFAULT_BASE >> 12;
if (sipi_vector > max_vector_loc) {
printf("SIPI vector too large! 0x%08x\n",
sipi_vector);
return -1;
}
debug("Attempting to start %d APs\n", ap_count);
if ((lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY)) {
debug("Waiting for ICR not to be busy...");
if (apic_wait_timeout(1000, 50)) {
debug("timed out. Aborting.\n");
return -1;
} else {
debug("done.\n");
}
}
/* Send INIT IPI to all but self */
lapic_write(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(0));
lapic_write(LAPIC_ICR, LAPIC_DEST_ALLBUT | LAPIC_INT_ASSERT |
LAPIC_DM_INIT);
debug("Waiting for 10ms after sending INIT.\n");
mdelay(10);
/* Send 1st SIPI */
if ((lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY)) {
debug("Waiting for ICR not to be busy...");
if (apic_wait_timeout(1000, 50)) {
debug("timed out. Aborting.\n");
return -1;
} else {
debug("done.\n");
}
}
lapic_write(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(0));
lapic_write(LAPIC_ICR, LAPIC_DEST_ALLBUT | LAPIC_INT_ASSERT |
LAPIC_DM_STARTUP | sipi_vector);
debug("Waiting for 1st SIPI to complete...");
if (apic_wait_timeout(10000, 50)) {
debug("timed out.\n");
return -1;
} else {
debug("done.\n");
}
/* Wait for CPUs to check in up to 200 us */
wait_for_aps(num_aps, ap_count, 200, 15);
/* Send 2nd SIPI */
if ((lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY)) {
debug("Waiting for ICR not to be busy...");
if (apic_wait_timeout(1000, 50)) {
debug("timed out. Aborting.\n");
return -1;
} else {
debug("done.\n");
}
}
lapic_write(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(0));
lapic_write(LAPIC_ICR, LAPIC_DEST_ALLBUT | LAPIC_INT_ASSERT |
LAPIC_DM_STARTUP | sipi_vector);
debug("Waiting for 2nd SIPI to complete...");
if (apic_wait_timeout(10000, 50)) {
debug("timed out.\n");
return -1;
} else {
debug("done.\n");
}
/* Wait for CPUs to check in */
if (wait_for_aps(num_aps, ap_count, 10000, 50)) {
debug("Not all APs checked in: %d/%d.\n",
atomic_read(num_aps), ap_count);
return -1;
}
return 0;
}
static int lapic_start_cpu(unsigned long apicid)
{
int timeout;
unsigned long send_status, accept_status;
int j, maxlvt;
/*
* Starting actual IPI sequence...
*/
printk(BIOS_SPEW, "Asserting INIT.\n");
/*
* Turn INIT on target chip
*/
lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
/*
* Send IPI
*/
lapic_write_around(LAPIC_ICR, LAPIC_INT_LEVELTRIG | LAPIC_INT_ASSERT
| LAPIC_DM_INIT);
printk(BIOS_SPEW, "Waiting for send to finish...\n");
timeout = 0;
do {
printk(BIOS_SPEW, "+");
udelay(100);
send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
if (timeout >= 1000) {
printk(BIOS_ERR, "CPU %ld: First APIC write timed out. "
"Disabling\n", apicid);
// too bad.
printk(BIOS_ERR, "ESR is 0x%lx\n", lapic_read(LAPIC_ESR));
if (lapic_read(LAPIC_ESR)) {
printk(BIOS_ERR, "Try to reset ESR\n");
lapic_write_around(LAPIC_ESR, 0);
printk(BIOS_ERR, "ESR is 0x%lx\n",
lapic_read(LAPIC_ESR));
}
return 0;
}
#if !IS_ENABLED(CONFIG_CPU_AMD_MODEL_10XXX) \
&& !IS_ENABLED(CONFIG_CPU_INTEL_MODEL_206AX) \
&& !IS_ENABLED(CONFIG_CPU_INTEL_MODEL_2065X)
mdelay(10);
#endif
printk(BIOS_SPEW, "Deasserting INIT.\n");
/* Target chip */
lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
/* Send IPI */
lapic_write_around(LAPIC_ICR, LAPIC_INT_LEVELTRIG | LAPIC_DM_INIT);
printk(BIOS_SPEW, "Waiting for send to finish...\n");
timeout = 0;
do {
printk(BIOS_SPEW, "+");
udelay(100);
send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
if (timeout >= 1000) {
printk(BIOS_ERR, "CPU %ld: Second APIC write timed out. "
"Disabling\n", apicid);
// too bad.
return 0;
}
/*
* Run STARTUP IPI loop.
*/
printk(BIOS_SPEW, "#startup loops: %d.\n", CONFIG_NUM_IPI_STARTS);
maxlvt = 4;
for (j = 1; j <= CONFIG_NUM_IPI_STARTS; j++) {
printk(BIOS_SPEW, "Sending STARTUP #%d to %lu.\n", j, apicid);
lapic_read_around(LAPIC_SPIV);
lapic_write(LAPIC_ESR, 0);
lapic_read(LAPIC_ESR);
printk(BIOS_SPEW, "After apic_write.\n");
/*
* STARTUP IPI
*/
/* Target chip */
lapic_write_around(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
/* Boot on the stack */
/* Kick the second */
lapic_write_around(LAPIC_ICR, LAPIC_DM_STARTUP
| (AP_SIPI_VECTOR >> 12));
/*
* Give the other CPU some time to accept the IPI.
*/
udelay(300);
printk(BIOS_SPEW, "Startup point 1.\n");
printk(BIOS_SPEW, "Waiting for send to finish...\n");
timeout = 0;
do {
printk(BIOS_SPEW, "+");
udelay(100);
send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
/*
* Give the other CPU some time to accept the IPI.
*/
udelay(200);
/*
* Due to the Pentium erratum 3AP.
*/
if (maxlvt > 3) {
lapic_read_around(LAPIC_SPIV);
lapic_write(LAPIC_ESR, 0);
}
accept_status = (lapic_read(LAPIC_ESR) & 0xEF);
if (send_status || accept_status)
break;
}
printk(BIOS_SPEW, "After Startup.\n");
if (send_status)
printk(BIOS_WARNING, "APIC never delivered???\n");
if (accept_status)
printk(BIOS_WARNING, "APIC delivery error (%lx).\n",
accept_status);
if (send_status || accept_status)
return 0;
return 1;
}
