1 /* 2 * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> 3 * Copyright (C) 2017 Stafford Horne <shorne@gmail.com> 4 * 5 * Based on arm64 and arc implementations 6 * Copyright (C) 2013 ARM Ltd. 7 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 8 * 9 * This file is licensed under the terms of the GNU General Public License 10 * version 2. This program is licensed "as is" without any warranty of any 11 * kind, whether express or implied. 12 */ 13 14 #include <linux/smp.h> 15 #include <linux/cpu.h> 16 #include <linux/sched.h> 17 #include <linux/sched/mm.h> 18 #include <linux/irq.h> 19 #include <linux/of.h> 20 #include <asm/cpuinfo.h> 21 #include <asm/mmu_context.h> 22 #include <asm/tlbflush.h> 23 #include <asm/cacheflush.h> 24 #include <asm/time.h> 25 26 asmlinkage __init void secondary_start_kernel(void); 27 28 static void (*smp_cross_call)(const struct cpumask *, unsigned int); 29 30 unsigned long secondary_release = -1; 31 struct thread_info *secondary_thread_info; 32 33 enum ipi_msg_type { 34 IPI_WAKEUP, 35 IPI_RESCHEDULE, 36 IPI_CALL_FUNC, 37 IPI_CALL_FUNC_SINGLE, 38 }; 39 40 static DEFINE_SPINLOCK(boot_lock); 41 42 static void boot_secondary(unsigned int cpu, struct task_struct *idle) 43 { 44 /* 45 * set synchronisation state between this boot processor 46 * and the secondary one 47 */ 48 spin_lock(&boot_lock); 49 50 secondary_release = cpu; 51 smp_cross_call(cpumask_of(cpu), IPI_WAKEUP); 52 53 /* 54 * now the secondary core is starting up let it run its 55 * calibrations, then wait for it to finish 56 */ 57 spin_unlock(&boot_lock); 58 } 59 60 void __init smp_init_cpus(void) 61 { 62 struct device_node *cpu; 63 u32 cpu_id; 64 65 for_each_of_cpu_node(cpu) { 66 cpu_id = of_get_cpu_hwid(cpu, 0); 67 if (cpu_id < NR_CPUS) 68 set_cpu_possible(cpu_id, true); 69 } 70 } 71 72 void __init smp_prepare_cpus(unsigned int max_cpus) 73 { 74 unsigned int cpu; 75 76 /* 77 * Initialise the present map, which describes the set of CPUs 78 * actually populated at the present time. 79 */ 80 for_each_possible_cpu(cpu) { 81 if (cpu < max_cpus) 82 set_cpu_present(cpu, true); 83 } 84 } 85 86 void __init smp_cpus_done(unsigned int max_cpus) 87 { 88 } 89 90 static DECLARE_COMPLETION(cpu_running); 91 92 int __cpu_up(unsigned int cpu, struct task_struct *idle) 93 { 94 if (smp_cross_call == NULL) { 95 pr_warn("CPU%u: failed to start, IPI controller missing", 96 cpu); 97 return -EIO; 98 } 99 100 secondary_thread_info = task_thread_info(idle); 101 current_pgd[cpu] = init_mm.pgd; 102 103 boot_secondary(cpu, idle); 104 if (!wait_for_completion_timeout(&cpu_running, 105 msecs_to_jiffies(1000))) { 106 pr_crit("CPU%u: failed to start\n", cpu); 107 return -EIO; 108 } 109 synchronise_count_master(cpu); 110 111 return 0; 112 } 113 114 asmlinkage __init void secondary_start_kernel(void) 115 { 116 struct mm_struct *mm = &init_mm; 117 unsigned int cpu = smp_processor_id(); 118 /* 119 * All kernel threads share the same mm context; grab a 120 * reference and switch to it. 121 */ 122 mmgrab(mm); 123 current->active_mm = mm; 124 cpumask_set_cpu(cpu, mm_cpumask(mm)); 125 126 pr_info("CPU%u: Booted secondary processor\n", cpu); 127 128 setup_cpuinfo(); 129 openrisc_clockevent_init(); 130 131 notify_cpu_starting(cpu); 132 133 /* 134 * OK, now it's safe to let the boot CPU continue 135 */ 136 complete(&cpu_running); 137 138 synchronise_count_slave(cpu); 139 set_cpu_online(cpu, true); 140 141 local_irq_enable(); 142 /* 143 * OK, it's off to the idle thread for us 144 */ 145 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); 146 } 147 148 void handle_IPI(unsigned int ipi_msg) 149 { 150 unsigned int cpu = smp_processor_id(); 151 152 switch (ipi_msg) { 153 case IPI_WAKEUP: 154 break; 155 156 case IPI_RESCHEDULE: 157 scheduler_ipi(); 158 break; 159 160 case IPI_CALL_FUNC: 161 generic_smp_call_function_interrupt(); 162 break; 163 164 case IPI_CALL_FUNC_SINGLE: 165 generic_smp_call_function_single_interrupt(); 166 break; 167 168 default: 169 WARN(1, "CPU%u: Unknown IPI message 0x%x\n", cpu, ipi_msg); 170 break; 171 } 172 } 173 174 void arch_smp_send_reschedule(int cpu) 175 { 176 smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE); 177 } 178 179 static void stop_this_cpu(void *dummy) 180 { 181 /* Remove this CPU */ 182 set_cpu_online(smp_processor_id(), false); 183 184 local_irq_disable(); 185 /* CPU Doze */ 186 if (mfspr(SPR_UPR) & SPR_UPR_PMP) 187 mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME); 188 /* If that didn't work, infinite loop */ 189 while (1) 190 ; 191 } 192 193 void smp_send_stop(void) 194 { 195 smp_call_function(stop_this_cpu, NULL, 0); 196 } 197 198 void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int)) 199 { 200 smp_cross_call = fn; 201 } 202 203 void arch_send_call_function_single_ipi(int cpu) 204 { 205 smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE); 206 } 207 208 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 209 { 210 smp_cross_call(mask, IPI_CALL_FUNC); 211 } 212 213 /* TLB flush operations - Performed on each CPU*/ 214 static inline void ipi_flush_tlb_all(void *ignored) 215 { 216 local_flush_tlb_all(); 217 } 218 219 static inline void ipi_flush_tlb_mm(void *info) 220 { 221 struct mm_struct *mm = (struct mm_struct *)info; 222 223 local_flush_tlb_mm(mm); 224 } 225 226 static void smp_flush_tlb_mm(struct cpumask *cmask, struct mm_struct *mm) 227 { 228 unsigned int cpuid; 229 230 if (cpumask_empty(cmask)) 231 return; 232 233 cpuid = get_cpu(); 234 235 if (cpumask_any_but(cmask, cpuid) >= nr_cpu_ids) { 236 /* local cpu is the only cpu present in cpumask */ 237 local_flush_tlb_mm(mm); 238 } else { 239 on_each_cpu_mask(cmask, ipi_flush_tlb_mm, mm, 1); 240 } 241 put_cpu(); 242 } 243 244 struct flush_tlb_data { 245 unsigned long addr1; 246 unsigned long addr2; 247 }; 248 249 static inline void ipi_flush_tlb_page(void *info) 250 { 251 struct flush_tlb_data *fd = (struct flush_tlb_data *)info; 252 253 local_flush_tlb_page(NULL, fd->addr1); 254 } 255 256 static inline void ipi_flush_tlb_range(void *info) 257 { 258 struct flush_tlb_data *fd = (struct flush_tlb_data *)info; 259 260 local_flush_tlb_range(NULL, fd->addr1, fd->addr2); 261 } 262 263 static void smp_flush_tlb_range(const struct cpumask *cmask, unsigned long start, 264 unsigned long end) 265 { 266 unsigned int cpuid; 267 268 if (cpumask_empty(cmask)) 269 return; 270 271 cpuid = get_cpu(); 272 273 if (cpumask_any_but(cmask, cpuid) >= nr_cpu_ids) { 274 /* local cpu is the only cpu present in cpumask */ 275 if ((end - start) <= PAGE_SIZE) 276 local_flush_tlb_page(NULL, start); 277 else 278 local_flush_tlb_range(NULL, start, end); 279 } else { 280 struct flush_tlb_data fd; 281 282 fd.addr1 = start; 283 fd.addr2 = end; 284 285 if ((end - start) <= PAGE_SIZE) 286 on_each_cpu_mask(cmask, ipi_flush_tlb_page, &fd, 1); 287 else 288 on_each_cpu_mask(cmask, ipi_flush_tlb_range, &fd, 1); 289 } 290 put_cpu(); 291 } 292 293 void flush_tlb_all(void) 294 { 295 on_each_cpu(ipi_flush_tlb_all, NULL, 1); 296 } 297 298 void flush_tlb_mm(struct mm_struct *mm) 299 { 300 smp_flush_tlb_mm(mm_cpumask(mm), mm); 301 } 302 303 void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) 304 { 305 smp_flush_tlb_range(mm_cpumask(vma->vm_mm), uaddr, uaddr + PAGE_SIZE); 306 } 307 308 void flush_tlb_range(struct vm_area_struct *vma, 309 unsigned long start, unsigned long end) 310 { 311 const struct cpumask *cmask = vma ? mm_cpumask(vma->vm_mm) 312 : cpu_online_mask; 313 smp_flush_tlb_range(cmask, start, end); 314 } 315 316 /* Instruction cache invalidate - performed on each cpu */ 317 static void ipi_icache_page_inv(void *arg) 318 { 319 struct page *page = arg; 320 321 local_icache_page_inv(page); 322 } 323 324 void smp_icache_page_inv(struct page *page) 325 { 326 on_each_cpu(ipi_icache_page_inv, page, 1); 327 } 328 EXPORT_SYMBOL(smp_icache_page_inv); 329