1 /* 2 * Spin Table SMP initialisation 3 * 4 * Copyright (C) 2013 ARM Ltd. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #include <linux/init.h> 20 #include <linux/of.h> 21 #include <linux/smp.h> 22 23 #include <asm/cacheflush.h> 24 25 static phys_addr_t cpu_release_addr[NR_CPUS]; 26 27 static int __init smp_spin_table_init_cpu(struct device_node *dn, int cpu) 28 { 29 /* 30 * Determine the address from which the CPU is polling. 31 */ 32 if (of_property_read_u64(dn, "cpu-release-addr", 33 &cpu_release_addr[cpu])) { 34 pr_err("CPU %d: missing or invalid cpu-release-addr property\n", 35 cpu); 36 37 return -1; 38 } 39 40 return 0; 41 } 42 43 static int __init smp_spin_table_prepare_cpu(int cpu) 44 { 45 void **release_addr; 46 47 if (!cpu_release_addr[cpu]) 48 return -ENODEV; 49 50 release_addr = __va(cpu_release_addr[cpu]); 51 release_addr[0] = (void *)__pa(secondary_holding_pen); 52 __flush_dcache_area(release_addr, sizeof(release_addr[0])); 53 54 /* 55 * Send an event to wake up the secondary CPU. 56 */ 57 sev(); 58 59 return 0; 60 } 61 62 const struct smp_enable_ops smp_spin_table_ops __initconst = { 63 .name = "spin-table", 64 .init_cpu = smp_spin_table_init_cpu, 65 .prepare_cpu = smp_spin_table_prepare_cpu, 66 }; 67