arch/mips/kernel/smp-cmp.c

   1 /*
   2  *  This program is free software; you can distribute it and/or modify it
   3  *  under the terms of the GNU General Public License (Version 2) as
   4  *  published by the Free Software Foundation.
   5  *
   6  *  This program is distributed in the hope it will be useful, but WITHOUT
   7  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   8  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   9  *  for more details.
  10  *
  11  *  You should have received a copy of the GNU General Public License along
  12  *  with this program; if not, write to the Free Software Foundation, Inc.,
  13  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  14  *
  15  * Copyright (C) 2007 MIPS Technologies, Inc.
  16  *    Chris Dearman (chris@mips.com)
  17  */
  18
  19 #undef DEBUG
  20
  21 #include <linux/kernel.h>
  22 #include <linux/sched.h>
  23 #include <linux/smp.h>
  24 #include <linux/cpumask.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/compiler.h>
  27 #include <linux/irqchip/mips-gic.h>
  28
  29 #include <linux/atomic.h>
  30 #include <asm/cacheflush.h>
  31 #include <asm/cpu.h>
  32 #include <asm/processor.h>
  33 #include <asm/hardirq.h>
  34 #include <asm/mmu_context.h>
  35 #include <asm/smp.h>
  36 #include <asm/time.h>
  37 #include <asm/mipsregs.h>
  38 #include <asm/mipsmtregs.h>
  39 #include <asm/mips_mt.h>
  40 #include <asm/amon.h>
  41
  42 static void cmp_init_secondary(void)
  43 {
  44         struct cpuinfo_mips *c __maybe_unused = &current_cpu_data;
  45
  46         /* Assume GIC is present */
  47         change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 | STATUSF_IP4 |
  48                                  STATUSF_IP5 | STATUSF_IP6 | STATUSF_IP7);
  49
  50         /* Enable per-cpu interrupts: platform specific */
  51
  52 #ifdef CONFIG_MIPS_MT_SMP
  53         if (cpu_has_mipsmt)
  54                 c->vpe_id = (read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) &
  55                         TCBIND_CURVPE;
  56 #endif
  57 }
  58
  59 static void cmp_smp_finish(void)
  60 {
  61         pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
  62
  63         /* CDFIXME: remove this? */
  64         write_c0_compare(read_c0_count() + (8 * mips_hpt_frequency / HZ));
  65
  66 #ifdef CONFIG_MIPS_MT_FPAFF
  67         /* If we have an FPU, enroll ourselves in the FPU-full mask */
  68         if (cpu_has_fpu)
  69                 cpumask_set_cpu(smp_processor_id(), &mt_fpu_cpumask);
  70 #endif /* CONFIG_MIPS_MT_FPAFF */
  71
  72         local_irq_enable();
  73 }
  74
  75 /*
  76  * Setup the PC, SP, and GP of a secondary processor and start it running
  77  * smp_bootstrap is the place to resume from
  78  * __KSTK_TOS(idle) is apparently the stack pointer
  79  * (unsigned long)idle->thread_info the gp
  80  */
  81 static void cmp_boot_secondary(int cpu, struct task_struct *idle)
  82 {
  83         struct thread_info *gp = task_thread_info(idle);
  84         unsigned long sp = __KSTK_TOS(idle);
  85         unsigned long pc = (unsigned long)&smp_bootstrap;
  86         unsigned long a0 = 0;
  87
  88         pr_debug("SMPCMP: CPU%d: %s cpu %d\n", smp_processor_id(),
  89                 __func__, cpu);
  90
  91 #if 0
  92         /* Needed? */
  93         flush_icache_range((unsigned long)gp,
  94                            (unsigned long)(gp + sizeof(struct thread_info)));
  95 #endif
  96
  97         amon_cpu_start(cpu, pc, sp, (unsigned long)gp, a0);
  98 }
  99
 100 /*
 101  * Common setup before any secondaries are started
 102  */
 103 void __init cmp_smp_setup(void)
 104 {
 105         int i;
 106         int ncpu = 0;
 107
 108         pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
 109
 110 #ifdef CONFIG_MIPS_MT_FPAFF
 111         /* If we have an FPU, enroll ourselves in the FPU-full mask */
 112         if (cpu_has_fpu)
 113                 cpumask_set_cpu(0, &mt_fpu_cpumask);
 114 #endif /* CONFIG_MIPS_MT_FPAFF */
 115
 116         for (i = 1; i < NR_CPUS; i++) {
 117                 if (amon_cpu_avail(i)) {
 118                         set_cpu_possible(i, true);
 119                         __cpu_number_map[i]     = ++ncpu;
 120                         __cpu_logical_map[ncpu] = i;
 121                 }
 122         }
 123
 124         if (cpu_has_mipsmt) {
 125                 unsigned int nvpe = 1;
 126 #ifdef CONFIG_MIPS_MT_SMP
 127                 unsigned int mvpconf0 = read_c0_mvpconf0();
 128
 129                 nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
 130 #endif
 131                 smp_num_siblings = nvpe;
 132         }
 133         pr_info("Detected %i available secondary CPU(s)\n", ncpu);
 134 }
 135
 136 void __init cmp_prepare_cpus(unsigned int max_cpus)
 137 {
 138         pr_debug("SMPCMP: CPU%d: %s max_cpus=%d\n",
 139                  smp_processor_id(), __func__, max_cpus);
 140
 141 #ifdef CONFIG_MIPS_MT
 142         /*
 143          * FIXME: some of these options are per-system, some per-core and
 144          * some per-cpu
 145          */
 146         mips_mt_set_cpuoptions();
 147 #endif
 148
 149 }
 150
 151 struct plat_smp_ops cmp_smp_ops = {
 152         .send_ipi_single        = gic_send_ipi_single,
 153         .send_ipi_mask          = gic_send_ipi_mask,
 154         .init_secondary         = cmp_init_secondary,
 155         .smp_finish             = cmp_smp_finish,
 156         .boot_secondary         = cmp_boot_secondary,
 157         .smp_setup              = cmp_smp_setup,
 158         .prepare_cpus           = cmp_prepare_cpus,
 159 };