LXR linux/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
  20static int major;
  21
  22static 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
  42void _interrupt_sp(void)
  43{
  44        smp_send_reschedule(aprp_cpu_index());
  45}
  46
  47int __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                        while (i--)
  81                                device_destroy(mt_class, MKDEV(major, i));
  82
  83                        err = PTR_ERR(dev);
  84                        goto out_chrdev;
  85                }
  86        }
  87
  88        /* set up notifiers */
  89        rtlx_notify.start = rtlx_starting;
  90        rtlx_notify.stop = rtlx_stopping;
  91        vpe_notify(aprp_cpu_index(), &rtlx_notify);
  92
  93        if (cpu_has_vint) {
  94                aprp_hook = rtlx_interrupt;
  95        } else {
  96                pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
  97                err = -ENODEV;
  98                goto out_class;
  99        }
 100
 101        return 0;
 102
 103out_class:
 104        for (i = 0; i < RTLX_CHANNELS; i++)
 105                device_destroy(mt_class, MKDEV(major, i));
 106out_chrdev:
 107        unregister_chrdev(major, RTLX_MODULE_NAME);
 108
 109        return err;
 110}
 111
 112void __exit rtlx_module_exit(void)
 113{
 114        int i;
 115
 116        for (i = 0; i < RTLX_CHANNELS; i++)
 117                device_destroy(mt_class, MKDEV(major, i));
 118
 119        unregister_chrdev(major, RTLX_MODULE_NAME);
 120
 121        aprp_hook = NULL;
 122}
 123