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
  28 #include <linux/atomic.h>
  29 #include <asm/cacheflush.h>
  30 #include <asm/cpu.h>
  31 #include <asm/processor.h>
  32 #include <asm/hardirq.h>
  33 #include <asm/mmu_context.h>
  34 #include <asm/smp.h>
  35 #include <asm/time.h>
  36 #include <asm/mipsregs.h>
  37 #include <asm/mipsmtregs.h>
  38 #include <asm/mips_mt.h>
  39 #include <asm/amon.h>
  40 #include <asm/gic.h>
  41
  42 static void ipi_call_function(unsigned int cpu)
  43 {
  44         pr_debug("CPU%d: %s cpu %d status %08x\n",
  45                  smp_processor_id(), __func__, cpu, read_c0_status());
  46
  47         gic_send_ipi(plat_ipi_call_int_xlate(cpu));
  48 }
  49
  50
  51 static void ipi_resched(unsigned int cpu)
  52 {
  53         pr_debug("CPU%d: %s cpu %d status %08x\n",
  54                  smp_processor_id(), __func__, cpu, read_c0_status());
  55
  56         gic_send_ipi(plat_ipi_resched_int_xlate(cpu));
  57 }
  58
  59 /*
  60  * FIXME: This isn't restricted to CMP
  61  * The SMVP kernel could use GIC interrupts if available
  62  */
  63 void cmp_send_ipi_single(int cpu, unsigned int action)
  64 {
  65         unsigned long flags;
  66
  67         local_irq_save(flags);
  68
  69         switch (action) {
  70         case SMP_CALL_FUNCTION:
  71                 ipi_call_function(cpu);
  72                 break;
  73
  74         case SMP_RESCHEDULE_YOURSELF:
  75                 ipi_resched(cpu);
  76                 break;
  77         }
  78
  79         local_irq_restore(flags);
  80 }
  81
  82 static void cmp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
  83 {
  84         unsigned int i;
  85
  86         for_each_cpu(i, mask)
  87                 cmp_send_ipi_single(i, action);
  88 }
  89
  90 static void cmp_init_secondary(void)
  91 {
  92         struct cpuinfo_mips *c = &current_cpu_data;
  93
  94         /* Assume GIC is present */
  95         change_c0_status(ST0_IM, STATUSF_IP3 | STATUSF_IP4 | STATUSF_IP6 |
  96                                  STATUSF_IP7);
  97
  98         /* Enable per-cpu interrupts: platform specific */
  99
 100         c->core = (read_c0_ebase() >> 1) & 0x1ff;
 101 #if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC)
 102         c->vpe_id = (read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) & TCBIND_CURVPE;
 103 #endif
 104 #ifdef CONFIG_MIPS_MT_SMTC
 105         c->tc_id  = (read_c0_tcbind() & TCBIND_CURTC) >> TCBIND_CURTC_SHIFT;
 106 #endif
 107 }
 108
 109 static void cmp_smp_finish(void)
 110 {
 111         pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
 112
 113         /* CDFIXME: remove this? */
 114         write_c0_compare(read_c0_count() + (8 * mips_hpt_frequency / HZ));
 115
 116 #ifdef CONFIG_MIPS_MT_FPAFF
 117         /* If we have an FPU, enroll ourselves in the FPU-full mask */
 118         if (cpu_has_fpu)
 119                 cpu_set(smp_processor_id(), mt_fpu_cpumask);
 120 #endif /* CONFIG_MIPS_MT_FPAFF */
 121
 122         local_irq_enable();
 123 }
 124
 125 static void cmp_cpus_done(void)
 126 {
 127         pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
 128 }
 129
 130 /*
 131  * Setup the PC, SP, and GP of a secondary processor and start it running
 132  * smp_bootstrap is the place to resume from
 133  * __KSTK_TOS(idle) is apparently the stack pointer
 134  * (unsigned long)idle->thread_info the gp
 135  */
 136 static void cmp_boot_secondary(int cpu, struct task_struct *idle)
 137 {
 138         struct thread_info *gp = task_thread_info(idle);
 139         unsigned long sp = __KSTK_TOS(idle);
 140         unsigned long pc = (unsigned long)&smp_bootstrap;
 141         unsigned long a0 = 0;
 142
 143         pr_debug("SMPCMP: CPU%d: %s cpu %d\n", smp_processor_id(),
 144                 __func__, cpu);
 145
 146 #if 0
 147         /* Needed? */
 148         flush_icache_range((unsigned long)gp,
 149                            (unsigned long)(gp + sizeof(struct thread_info)));
 150 #endif
 151
 152         amon_cpu_start(cpu, pc, sp, (unsigned long)gp, a0);
 153 }
 154
 155 /*
 156  * Common setup before any secondaries are started
 157  */
 158 void __init cmp_smp_setup(void)
 159 {
 160         int i;
 161         int ncpu = 0;
 162
 163         pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__);
 164
 165 #ifdef CONFIG_MIPS_MT_FPAFF
 166         /* If we have an FPU, enroll ourselves in the FPU-full mask */
 167         if (cpu_has_fpu)
 168                 cpu_set(0, mt_fpu_cpumask);
 169 #endif /* CONFIG_MIPS_MT_FPAFF */
 170
 171         for (i = 1; i < NR_CPUS; i++) {
 172                 if (amon_cpu_avail(i)) {
 173                         set_cpu_possible(i, true);
 174                         __cpu_number_map[i]     = ++ncpu;
 175                         __cpu_logical_map[ncpu] = i;
 176                 }
 177         }
 178
 179         if (cpu_has_mipsmt) {
 180                 unsigned int nvpe, mvpconf0 = read_c0_mvpconf0();
 181
 182                 nvpe = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
 183                 smp_num_siblings = nvpe;
 184         }
 185         pr_info("Detected %i available secondary CPU(s)\n", ncpu);
 186 }
 187
 188 void __init cmp_prepare_cpus(unsigned int max_cpus)
 189 {
 190         pr_debug("SMPCMP: CPU%d: %s max_cpus=%d\n",
 191                  smp_processor_id(), __func__, max_cpus);
 192
 193         /*
 194          * FIXME: some of these options are per-system, some per-core and
 195          * some per-cpu
 196          */
 197         mips_mt_set_cpuoptions();
 198 }
 199
 200 struct plat_smp_ops cmp_smp_ops = {
 201         .send_ipi_single        = cmp_send_ipi_single,
 202         .send_ipi_mask          = cmp_send_ipi_mask,
 203         .init_secondary         = cmp_init_secondary,
 204         .smp_finish             = cmp_smp_finish,
 205         .cpus_done              = cmp_cpus_done,
 206         .boot_secondary         = cmp_boot_secondary,
 207         .smp_setup              = cmp_smp_setup,
 208         .prepare_cpus           = cmp_prepare_cpus,
 209 };