LXR linux/arch/mips/kernel/rtlx-mt.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/interrupt.h>
  15#include <linux/irq.h>
  16
  17#include <asm/mips_mt.h>
  18#include <asm/vpe.h>
  19#include <asm/rtlx.h>
  20
  21static int major;
  22
  23static void rtlx_dispatch(void)
  24{
  25        if (read_c0_cause() & read_c0_status() & C_SW0)
  26                do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ);
  27}
  28
  29/*
  30 * Interrupt handler may be called before rtlx_init has otherwise had
  31 * a chance to run.
  32 */
  33static irqreturn_t rtlx_interrupt(int irq, void *dev_id)
  34{
  35        unsigned int vpeflags;
  36        unsigned long flags;
  37        int i;
  38
  39        local_irq_save(flags);
  40        vpeflags = dvpe();
  41        set_c0_status(0x100 << MIPS_CPU_RTLX_IRQ);
  42        irq_enable_hazard();
  43        evpe(vpeflags);
  44        local_irq_restore(flags);
  45
  46        for (i = 0; i < RTLX_CHANNELS; i++) {
  47                wake_up(&channel_wqs[i].lx_queue);
  48                wake_up(&channel_wqs[i].rt_queue);
  49        }
  50
  51        return IRQ_HANDLED;
  52}
  53
  54static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;
  55
  56void _interrupt_sp(void)
  57{
  58        unsigned long flags;
  59
  60        local_irq_save(flags);
  61        dvpe();
  62        settc(1);
  63        write_vpe_c0_cause(read_vpe_c0_cause() | C_SW0);
  64        evpe(EVPE_ENABLE);
  65        local_irq_restore(flags);
  66}
  67
  68int __init rtlx_module_init(void)
  69{
  70        struct device *dev;
  71        int i, err;
  72
  73        if (!cpu_has_mipsmt) {
  74                pr_warn("VPE loader: not a MIPS MT capable processor\n");
  75                return -ENODEV;
  76        }
  77
  78        if (aprp_cpu_index() == 0) {
  79                pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n"
  80                        "Pass maxtcs=<n> argument as kernel argument\n");
  81
  82                return -ENODEV;
  83        }
  84
  85        major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops);
  86        if (major < 0) {
  87                pr_err("rtlx_module_init: unable to register device\n");
  88                return major;
  89        }
  90
  91        /* initialise the wait queues */
  92        for (i = 0; i < RTLX_CHANNELS; i++) {
  93                init_waitqueue_head(&channel_wqs[i].rt_queue);
  94                init_waitqueue_head(&channel_wqs[i].lx_queue);
  95                atomic_set(&channel_wqs[i].in_open, 0);
  96                mutex_init(&channel_wqs[i].mutex);
  97
  98                dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
  99                                    "%s%d", RTLX_MODULE_NAME, i);
 100                if (IS_ERR(dev)) {
 101                        while (i--)
 102                                device_destroy(mt_class, MKDEV(major, i));
 103
 104                        err = PTR_ERR(dev);
 105                        goto out_chrdev;
 106                }
 107        }
 108
 109        /* set up notifiers */
 110        rtlx_notify.start = rtlx_starting;
 111        rtlx_notify.stop = rtlx_stopping;
 112        vpe_notify(aprp_cpu_index(), &rtlx_notify);
 113
 114        if (cpu_has_vint) {
 115                aprp_hook = rtlx_dispatch;
 116        } else {
 117                pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
 118                err = -ENODEV;
 119                goto out_class;
 120        }
 121
 122        err = request_irq(rtlx_irq_num, rtlx_interrupt, 0, "RTLX", rtlx);
 123        if (err)
 124                goto out_class;
 125
 126        return 0;
 127
 128out_class:
 129        for (i = 0; i < RTLX_CHANNELS; i++)
 130                device_destroy(mt_class, MKDEV(major, i));
 131out_chrdev:
 132        unregister_chrdev(major, RTLX_MODULE_NAME);
 133
 134        return err;
 135}
 136
 137void __exit rtlx_module_exit(void)
 138{
 139        int i;
 140
 141        for (i = 0; i < RTLX_CHANNELS; i++)
 142                device_destroy(mt_class, MKDEV(major, i));
 143
 144        unregister_chrdev(major, RTLX_MODULE_NAME);
 145
 146        aprp_hook = NULL;
 147}
 148