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}