arch/mips/kernel/rtlx-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) 2005 MIPS Technologies, Inc.  All rights reserved.
   7  * Copyright (C) 2013 Imagination Technologies Ltd.
   8  */
   9 #include <linux/device.h>
  10 #include <linux/fs.h>
  11 #include <linux/err.h>
  12 #include <linux/wait.h>
  13 #include <linux/sched.h>
  14 #include <linux/smp.h>
  15
  16 #include <asm/mips_mt.h>
  17 #include <asm/vpe.h>
  18 #include <asm/rtlx.h>
  19
  20 static int major;
  21
  22 static void rtlx_interrupt(void)
  23 {
  24         int i;
  25         struct rtlx_info *info;
  26         struct rtlx_info **p = vpe_get_shared(aprp_cpu_index());
  27
  28         if (p == NULL || *p == NULL)
  29                 return;
  30
  31         info = *p;
  32
  33         if (info->ap_int_pending == 1 && smp_processor_id() == 0) {
  34                 for (i = 0; i < RTLX_CHANNELS; i++) {
  35                         wake_up(&channel_wqs[i].lx_queue);
  36                         wake_up(&channel_wqs[i].rt_queue);
  37                 }
  38                 info->ap_int_pending = 0;
  39         }
  40 }
  41
  42 void _interrupt_sp(void)
  43 {
  44         smp_send_reschedule(aprp_cpu_index());
  45 }
  46
  47 int __init rtlx_module_init(void)
  48 {
  49         struct device *dev;
  50         int i, err;
  51
  52         if (!cpu_has_mipsmt) {
  53                 pr_warn("VPE loader: not a MIPS MT capable processor\n");
  54                 return -ENODEV;
  55         }
  56
  57         if (num_possible_cpus() - aprp_cpu_index() < 1) {
  58                 pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n"
  59                         "Pass maxcpus=<n> argument as kernel argument\n");
  60
  61                 return -ENODEV;
  62         }
  63
  64         major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops);
  65         if (major < 0) {
  66                 pr_err("rtlx_module_init: unable to register device\n");
  67                 return major;
  68         }
  69
  70         /* initialise the wait queues */
  71         for (i = 0; i < RTLX_CHANNELS; i++) {
  72                 init_waitqueue_head(&channel_wqs[i].rt_queue);
  73                 init_waitqueue_head(&channel_wqs[i].lx_queue);
  74                 atomic_set(&channel_wqs[i].in_open, 0);
  75                 mutex_init(&channel_wqs[i].mutex);
  76
  77                 dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
  78                                     "%s%d", RTLX_MODULE_NAME, i);
  79                 if (IS_ERR(dev)) {
  80                         err = PTR_ERR(dev);
  81                         goto out_chrdev;
  82                 }
  83         }
  84
  85         /* set up notifiers */
  86         rtlx_notify.start = rtlx_starting;
  87         rtlx_notify.stop = rtlx_stopping;
  88         vpe_notify(aprp_cpu_index(), &rtlx_notify);
  89
  90         if (cpu_has_vint) {
  91                 aprp_hook = rtlx_interrupt;
  92         } else {
  93                 pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
  94                 err = -ENODEV;
  95                 goto out_class;
  96         }
  97
  98         return 0;
  99
 100 out_class:
 101         for (i = 0; i < RTLX_CHANNELS; i++)
 102                 device_destroy(mt_class, MKDEV(major, i));
 103 out_chrdev:
 104         unregister_chrdev(major, RTLX_MODULE_NAME);
 105
 106         return err;
 107 }
 108
 109 void __exit rtlx_module_exit(void)
 110 {
 111         int i;
 112
 113         for (i = 0; i < RTLX_CHANNELS; i++)
 114                 device_destroy(mt_class, MKDEV(major, i));
 115
 116         unregister_chrdev(major, RTLX_MODULE_NAME);
 117
 118         aprp_hook = NULL;
 119 }