arch/openrisc/kernel/smp.c

   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_prepare_boot_cpu(void)
  61 {
  62 }
  63
  64 void __init smp_init_cpus(void)
  65 {
  66         struct device_node *cpu;
  67         u32 cpu_id;
  68
  69         for_each_of_cpu_node(cpu) {
  70                 cpu_id = of_get_cpu_hwid(cpu, 0);
  71                 if (cpu_id < NR_CPUS)
  72                         set_cpu_possible(cpu_id, true);
  73         }
  74 }
  75
  76 void __init smp_prepare_cpus(unsigned int max_cpus)
  77 {
  78         unsigned int cpu;
  79
  80         /*
  81          * Initialise the present map, which describes the set of CPUs
  82          * actually populated at the present time.
  83          */
  84         for_each_possible_cpu(cpu) {
  85                 if (cpu < max_cpus)
  86                         set_cpu_present(cpu, true);
  87         }
  88 }
  89
  90 void __init smp_cpus_done(unsigned int max_cpus)
  91 {
  92 }
  93
  94 static DECLARE_COMPLETION(cpu_running);
  95
  96 int __cpu_up(unsigned int cpu, struct task_struct *idle)
  97 {
  98         if (smp_cross_call == NULL) {
  99                 pr_warn("CPU%u: failed to start, IPI controller missing",
 100                         cpu);
 101                 return -EIO;
 102         }
 103
 104         secondary_thread_info = task_thread_info(idle);
 105         current_pgd[cpu] = init_mm.pgd;
 106
 107         boot_secondary(cpu, idle);
 108         if (!wait_for_completion_timeout(&cpu_running,
 109                                         msecs_to_jiffies(1000))) {
 110                 pr_crit("CPU%u: failed to start\n", cpu);
 111                 return -EIO;
 112         }
 113         synchronise_count_master(cpu);
 114
 115         return 0;
 116 }
 117
 118 asmlinkage __init void secondary_start_kernel(void)
 119 {
 120         struct mm_struct *mm = &init_mm;
 121         unsigned int cpu = smp_processor_id();
 122         /*
 123          * All kernel threads share the same mm context; grab a
 124          * reference and switch to it.
 125          */
 126         mmgrab(mm);
 127         current->active_mm = mm;
 128         cpumask_set_cpu(cpu, mm_cpumask(mm));
 129
 130         pr_info("CPU%u: Booted secondary processor\n", cpu);
 131
 132         setup_cpuinfo();
 133         openrisc_clockevent_init();
 134
 135         notify_cpu_starting(cpu);
 136
 137         /*
 138          * OK, now it's safe to let the boot CPU continue
 139          */
 140         complete(&cpu_running);
 141
 142         synchronise_count_slave(cpu);
 143         set_cpu_online(cpu, true);
 144
 145         local_irq_enable();
 146         /*
 147          * OK, it's off to the idle thread for us
 148          */
 149         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 150 }
 151
 152 void handle_IPI(unsigned int ipi_msg)
 153 {
 154         unsigned int cpu = smp_processor_id();
 155
 156         switch (ipi_msg) {
 157         case IPI_WAKEUP:
 158                 break;
 159
 160         case IPI_RESCHEDULE:
 161                 scheduler_ipi();
 162                 break;
 163
 164         case IPI_CALL_FUNC:
 165                 generic_smp_call_function_interrupt();
 166                 break;
 167
 168         case IPI_CALL_FUNC_SINGLE:
 169                 generic_smp_call_function_single_interrupt();
 170                 break;
 171
 172         default:
 173                 WARN(1, "CPU%u: Unknown IPI message 0x%x\n", cpu, ipi_msg);
 174                 break;
 175         }
 176 }
 177
 178 void arch_smp_send_reschedule(int cpu)
 179 {
 180         smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
 181 }
 182
 183 static void stop_this_cpu(void *dummy)
 184 {
 185         /* Remove this CPU */
 186         set_cpu_online(smp_processor_id(), false);
 187
 188         local_irq_disable();
 189         /* CPU Doze */
 190         if (mfspr(SPR_UPR) & SPR_UPR_PMP)
 191                 mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME);
 192         /* If that didn't work, infinite loop */
 193         while (1)
 194                 ;
 195 }
 196
 197 void smp_send_stop(void)
 198 {
 199         smp_call_function(stop_this_cpu, NULL, 0);
 200 }
 201
 202 void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int))
 203 {
 204         smp_cross_call = fn;
 205 }
 206
 207 void arch_send_call_function_single_ipi(int cpu)
 208 {
 209         smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
 210 }
 211
 212 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 213 {
 214         smp_cross_call(mask, IPI_CALL_FUNC);
 215 }
 216
 217 /* TLB flush operations - Performed on each CPU*/
 218 static inline void ipi_flush_tlb_all(void *ignored)
 219 {
 220         local_flush_tlb_all();
 221 }
 222
 223 static inline void ipi_flush_tlb_mm(void *info)
 224 {
 225         struct mm_struct *mm = (struct mm_struct *)info;
 226
 227         local_flush_tlb_mm(mm);
 228 }
 229
 230 static void smp_flush_tlb_mm(struct cpumask *cmask, struct mm_struct *mm)
 231 {
 232         unsigned int cpuid;
 233
 234         if (cpumask_empty(cmask))
 235                 return;
 236
 237         cpuid = get_cpu();
 238
 239         if (cpumask_any_but(cmask, cpuid) >= nr_cpu_ids) {
 240                 /* local cpu is the only cpu present in cpumask */
 241                 local_flush_tlb_mm(mm);
 242         } else {
 243                 on_each_cpu_mask(cmask, ipi_flush_tlb_mm, mm, 1);
 244         }
 245         put_cpu();
 246 }
 247
 248 struct flush_tlb_data {
 249         unsigned long addr1;
 250         unsigned long addr2;
 251 };
 252
 253 static inline void ipi_flush_tlb_page(void *info)
 254 {
 255         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 256
 257         local_flush_tlb_page(NULL, fd->addr1);
 258 }
 259
 260 static inline void ipi_flush_tlb_range(void *info)
 261 {
 262         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 263
 264         local_flush_tlb_range(NULL, fd->addr1, fd->addr2);
 265 }
 266
 267 static void smp_flush_tlb_range(const struct cpumask *cmask, unsigned long start,
 268                                 unsigned long end)
 269 {
 270         unsigned int cpuid;
 271
 272         if (cpumask_empty(cmask))
 273                 return;
 274
 275         cpuid = get_cpu();
 276
 277         if (cpumask_any_but(cmask, cpuid) >= nr_cpu_ids) {
 278                 /* local cpu is the only cpu present in cpumask */
 279                 if ((end - start) <= PAGE_SIZE)
 280                         local_flush_tlb_page(NULL, start);
 281                 else
 282                         local_flush_tlb_range(NULL, start, end);
 283         } else {
 284                 struct flush_tlb_data fd;
 285
 286                 fd.addr1 = start;
 287                 fd.addr2 = end;
 288
 289                 if ((end - start) <= PAGE_SIZE)
 290                         on_each_cpu_mask(cmask, ipi_flush_tlb_page, &fd, 1);
 291                 else
 292                         on_each_cpu_mask(cmask, ipi_flush_tlb_range, &fd, 1);
 293         }
 294         put_cpu();
 295 }
 296
 297 void flush_tlb_all(void)
 298 {
 299         on_each_cpu(ipi_flush_tlb_all, NULL, 1);
 300 }
 301
 302 void flush_tlb_mm(struct mm_struct *mm)
 303 {
 304         smp_flush_tlb_mm(mm_cpumask(mm), mm);
 305 }
 306
 307 void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
 308 {
 309         smp_flush_tlb_range(mm_cpumask(vma->vm_mm), uaddr, uaddr + PAGE_SIZE);
 310 }
 311
 312 void flush_tlb_range(struct vm_area_struct *vma,
 313                      unsigned long start, unsigned long end)
 314 {
 315         const struct cpumask *cmask = vma ? mm_cpumask(vma->vm_mm)
 316                                           : cpu_online_mask;
 317         smp_flush_tlb_range(cmask, start, end);
 318 }
 319
 320 /* Instruction cache invalidate - performed on each cpu */
 321 static void ipi_icache_page_inv(void *arg)
 322 {
 323         struct page *page = arg;
 324
 325         local_icache_page_inv(page);
 326 }
 327
 328 void smp_icache_page_inv(struct page *page)
 329 {
 330         on_each_cpu(ipi_icache_page_inv, page, 1);
 331 }
 332 EXPORT_SYMBOL(smp_icache_page_inv);