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
  17 static int major;
  18
  19 void cleanup_tc(struct tc *tc)
  20 {
  21
  22 }
  23
  24 static 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 }
  38 static DEVICE_ATTR(kill, S_IWUSR, NULL, store_kill);
  39
  40 static 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
  48 static 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 }
  67 static DEVICE_ATTR_RW(ntcs);
  68
  69 static struct attribute *vpe_attrs[] = {
  70         &dev_attr_kill.attr,
  71         &dev_attr_ntcs.attr,
  72         NULL,
  73 };
  74 ATTRIBUTE_GROUPS(vpe);
  75
  76 static void vpe_device_release(struct device *cd)
  77 {
  78         kfree(cd);
  79 }
  80
  81 static struct class vpe_class = {
  82         .name = "vpe",
  83         .owner = THIS_MODULE,
  84         .dev_release = vpe_device_release,
  85         .dev_groups = vpe_groups,
  86 };
  87
  88 static struct device vpe_device;
  89
  90 int __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
 156 out_dev:
 157         device_del(&vpe_device);
 158
 159 out_class:
 160         class_unregister(&vpe_class);
 161
 162 out_chrdev:
 163         unregister_chrdev(major, VPE_MODULE_NAME);
 164
 165         return err;
 166 }
 167
 168 void __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 }