LXR linux/arch/mips/kernel/vpe-cmp.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) 2004, 2005 MIPS Technologies, Inc.  All rights reserved.
   7 * Copyright (C) 2013 Imagination Technologies Ltd.
   8 */
   9#include <linux/kernel.h>
  10#include <linux/device.h>
  11#include <linux/fs.h>
  12#include <linux/slab.h>
  13#include <linux/export.h>
  14
  15#include <asm/vpe.h>
  16
  17static int major;
  18
  19void cleanup_tc(struct tc *tc)
  20{
  21
  22}
  23
  24static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
  25                          const char *buf, size_t len)
  26{
  27        struct vpe *vpe = get_vpe(aprp_cpu_index());
  28        struct vpe_notifications *notifier;
  29
  30        list_for_each_entry(notifier, &vpe->notify, list)
  31                notifier->stop(aprp_cpu_index());
  32
  33        release_progmem(vpe->load_addr);
  34        vpe->state = VPE_STATE_UNUSED;
  35
  36        return len;
  37}
  38static DEVICE_ATTR(kill, S_IWUSR, NULL, store_kill);
  39
  40static ssize_t ntcs_show(struct device *cd, struct device_attribute *attr,
  41                         char *buf)
  42{
  43        struct vpe *vpe = get_vpe(aprp_cpu_index());
  44
  45        return sprintf(buf, "%d\n", vpe->ntcs);
  46}
  47
  48static ssize_t ntcs_store(struct device *dev, struct device_attribute *attr,
  49                          const char *buf, size_t len)
  50{
  51        struct vpe *vpe = get_vpe(aprp_cpu_index());
  52        unsigned long new;
  53        int ret;
  54
  55        ret = kstrtoul(buf, 0, &new);
  56        if (ret < 0)
  57                return ret;
  58
  59        /* APRP can only reserve one TC in a VPE and no more. */
  60        if (new != 1)
  61                return -EINVAL;
  62
  63        vpe->ntcs = new;
  64
  65        return len;
  66}
  67static DEVICE_ATTR_RW(ntcs);
  68
  69static struct attribute *vpe_attrs[] = {
  70        &dev_attr_kill.attr,
  71        &dev_attr_ntcs.attr,
  72        NULL,
  73};
  74ATTRIBUTE_GROUPS(vpe);
  75
  76static void vpe_device_release(struct device *cd)
  77{
  78        kfree(cd);
  79}
  80
  81static struct class vpe_class = {
  82        .name = "vpe",
  83        .owner = THIS_MODULE,
  84        .dev_release = vpe_device_release,
  85        .dev_groups = vpe_groups,
  86};
  87
  88static struct device vpe_device;
  89
  90int __init vpe_module_init(void)
  91{
  92        struct vpe *v = NULL;
  93        struct tc *t;
  94        int err;
  95
  96        if (!cpu_has_mipsmt) {
  97                pr_warn("VPE loader: not a MIPS MT capable processor\n");
  98                return -ENODEV;
  99        }
 100
 101        if (num_possible_cpus() - aprp_cpu_index() < 1) {
 102                pr_warn("No VPEs reserved for AP/SP, not initialize VPE loader\n"
 103                        "Pass maxcpus=<n> argument as kernel argument\n");
 104                return -ENODEV;
 105        }
 106
 107        major = register_chrdev(0, VPE_MODULE_NAME, &vpe_fops);
 108        if (major < 0) {
 109                pr_warn("VPE loader: unable to register character device\n");
 110                return major;
 111        }
 112
 113        err = class_register(&vpe_class);
 114        if (err) {
 115                pr_err("vpe_class registration failed\n");
 116                goto out_chrdev;
 117        }
 118
 119        device_initialize(&vpe_device);
 120        vpe_device.class        = &vpe_class;
 121        vpe_device.parent       = NULL;
 122        dev_set_name(&vpe_device, "vpe_sp");
 123        vpe_device.devt = MKDEV(major, VPE_MODULE_MINOR);
 124        err = device_add(&vpe_device);
 125        if (err) {
 126                pr_err("Adding vpe_device failed\n");
 127                goto out_class;
 128        }
 129
 130        t = alloc_tc(aprp_cpu_index());
 131        if (!t) {
 132                pr_warn("VPE: unable to allocate TC\n");
 133                err = -ENOMEM;
 134                goto out_dev;
 135        }
 136
 137        /* VPE */
 138        v = alloc_vpe(aprp_cpu_index());
 139        if (v == NULL) {
 140                pr_warn("VPE: unable to allocate VPE\n");
 141                kfree(t);
 142                err = -ENOMEM;
 143                goto out_dev;
 144        }
 145
 146        v->ntcs = 1;
 147
 148        /* add the tc to the list of this vpe's tc's. */
 149        list_add(&t->tc, &v->tc);
 150
 151        /* TC */
 152        t->pvpe = v;    /* set the parent vpe */
 153
 154        return 0;
 155
 156out_dev:
 157        device_del(&vpe_device);
 158
 159out_class:
 160        class_unregister(&vpe_class);
 161
 162out_chrdev:
 163        unregister_chrdev(major, VPE_MODULE_NAME);
 164
 165        return err;
 166}
 167
 168void __exit vpe_module_exit(void)
 169{
 170        struct vpe *v, *n;
 171
 172        device_del(&vpe_device);
 173        class_unregister(&vpe_class);
 174        unregister_chrdev(major, VPE_MODULE_NAME);
 175
 176        /* No locking needed here */
 177        list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list)
 178                if (v->state != VPE_STATE_UNUSED)
 179                        release_vpe(v);
 180}
 181