LXR linux/arch/mips/mti-malta/malta-amon.c

   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 2007 MIPS Technologies, Inc.  All rights reserved.
   7 * Copyright (C) 2013 Imagination Technologies Ltd.
   8 *
   9 * Arbitrary Monitor Interface
  10 */
  11#include <linux/kernel.h>
  12#include <linux/smp.h>
  13
  14#include <asm/addrspace.h>
  15#include <asm/mipsmtregs.h>
  16#include <asm/mips-boards/launch.h>
  17#include <asm/vpe.h>
  18
  19int amon_cpu_avail(int cpu)
  20{
  21        struct cpulaunch *launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
  22
  23        if (cpu < 0 || cpu >= NCPULAUNCH) {
  24                pr_debug("avail: cpu%d is out of range\n", cpu);
  25                return 0;
  26        }
  27
  28        launch += cpu;
  29        if (!(launch->flags & LAUNCH_FREADY)) {
  30                pr_debug("avail: cpu%d is not ready\n", cpu);
  31                return 0;
  32        }
  33        if (launch->flags & (LAUNCH_FGO|LAUNCH_FGONE)) {
  34                pr_debug("avail: too late.. cpu%d is already gone\n", cpu);
  35                return 0;
  36        }
  37
  38        return 1;
  39}
  40
  41int amon_cpu_start(int cpu,
  42                    unsigned long pc, unsigned long sp,
  43                    unsigned long gp, unsigned long a0)
  44{
  45        volatile struct cpulaunch *launch =
  46                (struct cpulaunch  *)CKSEG0ADDR(CPULAUNCH);
  47
  48        if (!amon_cpu_avail(cpu))
  49                return -1;
  50        if (cpu == smp_processor_id()) {
  51                pr_debug("launch: I am cpu%d!\n", cpu);
  52                return -1;
  53        }
  54        launch += cpu;
  55
  56        pr_debug("launch: starting cpu%d\n", cpu);
  57
  58        launch->pc = pc;
  59        launch->gp = gp;
  60        launch->sp = sp;
  61        launch->a0 = a0;
  62
  63        smp_wmb();              /* Target must see parameters before go */
  64        launch->flags |= LAUNCH_FGO;
  65        smp_wmb();              /* Target must see go before we poll  */
  66
  67        while ((launch->flags & LAUNCH_FGONE) == 0)
  68                ;
  69        smp_rmb();      /* Target will be updating flags soon */
  70        pr_debug("launch: cpu%d gone!\n", cpu);
  71
  72        return 0;
  73}
  74
  75#ifdef CONFIG_MIPS_VPE_LOADER_CMP
  76int vpe_run(struct vpe *v)
  77{
  78        struct vpe_notifications *n;
  79
  80        if (amon_cpu_start(aprp_cpu_index(), v->__start, 0, 0, 0) < 0)
  81                return -1;
  82
  83        list_for_each_entry(n, &v->notify, list)
  84                n->start(VPE_MODULE_MINOR);
  85
  86        return 0;
  87}
  88#endif
  89