| // SPDX-License-Identifier: GPL-2.0 |
| #include <linux/delay.h> |
| #include <linux/init.h> |
| #include <linux/smp.h> |
| #include "smc.h" |
| |
| static int tango_boot_secondary(unsigned int cpu, struct task_struct *idle) |
| { |
| tango_set_aux_boot_addr(__pa_symbol(secondary_startup)); |
| tango_start_aux_core(cpu); |
| return 0; |
| } |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| /* |
| * cpu_kill() and cpu_die() run concurrently on different cores. |
| * Firmware will only "kill" a core once it has properly "died". |
| * Try a few times to kill a core before giving up, and sleep |
| * between tries to give that core enough time to die. |
| */ |
| static int tango_cpu_kill(unsigned int cpu) |
| { |
| int i, err; |
| |
| for (i = 0; i < 10; ++i) { |
| msleep(10); |
| err = tango_aux_core_kill(cpu); |
| if (!err) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static void tango_cpu_die(unsigned int cpu) |
| { |
| while (tango_aux_core_die(cpu) < 0) |
| cpu_relax(); |
| |
| panic("cpu %d failed to die\n", cpu); |
| } |
| #endif |
| |
| static const struct smp_operations tango_smp_ops __initconst = { |
| .smp_boot_secondary = tango_boot_secondary, |
| #ifdef CONFIG_HOTPLUG_CPU |
| .cpu_kill = tango_cpu_kill, |
| .cpu_die = tango_cpu_die, |
| #endif |
| }; |
| |
| CPU_METHOD_OF_DECLARE(tango4_smp, "sigma,tango4-smp", &tango_smp_ops); |