1 /* 2 * Secondary cpu support 3 * 4 * Copyright 2016 Suraj Jitindar Singh, IBM. 5 * 6 * This work is licensed under the terms of the GNU LGPL, version 2. 7 */ 8 9 #include <devicetree.h> 10 #include <asm/setup.h> 11 #include <asm/rtas.h> 12 #include <asm/smp.h> 13 14 int nr_threads; 15 16 struct secondary_entry_data { 17 secondary_entry_fn entry; 18 uint64_t r3; 19 int nr_started; 20 }; 21 22 /* 23 * Start stopped thread cpu_id at entry 24 * Returns: <0 on failure to start stopped cpu 25 * 0 on success 26 * >0 on cpu not in stopped state 27 */ 28 int start_thread(int cpu_id, secondary_entry_fn entry, uint32_t r3) 29 { 30 int query_token, start_token, outputs[1], ret; 31 32 query_token = rtas_token("query-cpu-stopped-state"); 33 start_token = rtas_token("start-cpu"); 34 assert(query_token != RTAS_UNKNOWN_SERVICE && 35 start_token != RTAS_UNKNOWN_SERVICE); 36 37 ret = rtas_call(query_token, 1, 2, outputs, cpu_id); 38 if (ret) { 39 printf("query-cpu-stopped-state failed for cpu %d\n", cpu_id); 40 } else if (!outputs[0]) { /* cpu in stopped state */ 41 ret = rtas_call(start_token, 3, 1, NULL, cpu_id, entry, r3); 42 if (ret) 43 printf("failed to start cpu %d\n", cpu_id); 44 } else { /* cpu not in stopped state */ 45 ret = outputs[0]; 46 } 47 48 return ret; 49 } 50 51 /* 52 * Start all stopped threads (vcpus) on cpu_node 53 * Returns: Number of stopped cpus which were successfully started 54 */ 55 struct start_threads start_cpu(int cpu_node, secondary_entry_fn entry, 56 uint32_t r3) 57 { 58 int len, i, nr_threads, nr_started = 0; 59 const struct fdt_property *prop; 60 u32 *threads; 61 62 /* Get the id array of threads on this cpu_node */ 63 prop = fdt_get_property(dt_fdt(), cpu_node, 64 "ibm,ppc-interrupt-server#s", &len); 65 assert(prop); 66 67 nr_threads = len >> 2; /* Divide by 4 since 4 bytes per thread */ 68 threads = (u32 *)prop->data; /* Array of valid ids */ 69 70 for (i = 0; i < nr_threads; i++) { 71 if (!start_thread(fdt32_to_cpu(threads[i]), entry, r3)) 72 nr_started++; 73 } 74 75 return (struct start_threads) { nr_threads, nr_started }; 76 } 77 78 static void start_each_secondary(int fdtnode, u32 regval __unused, void *info) 79 { 80 struct secondary_entry_data *datap = info; 81 struct start_threads ret = start_cpu(fdtnode, datap->entry, datap->r3); 82 83 nr_threads += ret.nr_threads; 84 datap->nr_started += ret.nr_started; 85 } 86 87 /* 88 * Start all stopped cpus on the guest at entry with register 3 set to r3 89 * We expect that we come in with only one thread currently started 90 * Returns: TRUE on success 91 * FALSE on failure 92 */ 93 bool start_all_cpus(secondary_entry_fn entry, uint32_t r3) 94 { 95 struct secondary_entry_data data = { entry, r3, 0 }; 96 int ret; 97 98 ret = dt_for_each_cpu_node(start_each_secondary, &data); 99 assert(ret == 0); 100 101 /* We expect that we come in with one thread already started */ 102 return data.nr_started == nr_threads - 1; 103 } 104