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_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);