Do not use printk on the running thread after it has been sent
the INIT IPI, execution may halt with console spinlock held.
Change-Id: I64608935ea740fb827fa0307442f3fb102de7a08
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/776
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Rudolf Marek <r.marek@assembler.cz>
}
#if CONFIG_AP_IN_SIPI_WAIT == 1
}
#if CONFIG_AP_IN_SIPI_WAIT == 1
+
+/**
+ * Sending INIT IPI to self is equivalent of asserting #INIT with a bit of delay.
+ * An undefined number of instruction cycles will complete. All global locks
+ * must be released before INIT IPI and no printk is allowed after this.
+ * De-asserting INIT IPI is a no-op on later Intel CPUs.
+ *
+ * If you set DEBUG_HALT_SELF to 1, printk's after INIT IPI are enabled
+ * but running thread may halt without releasing the lock and effectively
+ * deadlock other CPUs.
+ */
+#define DEBUG_HALT_SELF 0
+
/**
* 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.
/**
* 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.
lapic_write_around(LAPIC_ICR, LAPIC_INT_LEVELTRIG | LAPIC_INT_ASSERT | LAPIC_DM_INIT);
/* wait for the ipi send to finish */
lapic_write_around(LAPIC_ICR, LAPIC_INT_LEVELTRIG | LAPIC_INT_ASSERT | LAPIC_DM_INIT);
/* wait for the ipi send to finish */
-#if 0
- // When these two printk(BIOS_SPEW, ...) calls are not removed, the
- // machine will hang when log level is SPEW. Why?
printk(BIOS_SPEW, "Waiting for send to finish...\n");
#endif
timeout = 0;
do {
printk(BIOS_SPEW, "Waiting for send to finish...\n");
#endif
timeout = 0;
do {
printk(BIOS_SPEW, "+");
#endif
udelay(100);
send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
if (timeout >= 1000) {
printk(BIOS_SPEW, "+");
#endif
udelay(100);
send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
if (timeout >= 1000) {
printk(BIOS_ERR, "timed out\n");
printk(BIOS_ERR, "timed out\n");
printk(BIOS_SPEW, "Deasserting INIT.\n");
printk(BIOS_SPEW, "Deasserting INIT.\n");
/* 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);
/* 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);
printk(BIOS_SPEW, "Waiting for send to finish...\n");
printk(BIOS_SPEW, "Waiting for send to finish...\n");
udelay(100);
send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
if (timeout >= 1000) {
udelay(100);
send_status = lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY;
} while (send_status && (timeout++ < 1000));
if (timeout >= 1000) {
printk(BIOS_ERR, "timed out\n");
printk(BIOS_ERR, "timed out\n");