mips/kernel/rtlx-mt.c

0001 /*
0002  * This file is subject to the terms and conditions of the GNU General Public
0003  * License.  See the file "COPYING" in the main directory of this archive
0004  * for more details.
0005  *
0006  * Copyright (C) 2005 MIPS Technologies, Inc.  All rights reserved.
0007  * Copyright (C) 2013 Imagination Technologies Ltd.
0008  */
0009 #include <linux/device.h>
0010 #include <linux/fs.h>
0011 #include <linux/err.h>
0012 #include <linux/wait.h>
0013 #include <linux/sched.h>
0014 #include <linux/interrupt.h>
0015 #include <linux/irq.h>
0016
0017 #include <asm/mips_mt.h>
0018 #include <asm/vpe.h>
0019 #include <asm/rtlx.h>
0020
0021 static int major;
0022
0023 static void rtlx_dispatch(void)
0024 {
0025     if (read_c0_cause() & read_c0_status() & C_SW0)
0026         do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ);
0027 }
0028
0029 /*
0030  * Interrupt handler may be called before rtlx_init has otherwise had
0031  * a chance to run.
0032  */
0033 static irqreturn_t rtlx_interrupt(int irq, void *dev_id)
0034 {
0035     unsigned int vpeflags;
0036     unsigned long flags;
0037     int i;
0038
0039     local_irq_save(flags);
0040     vpeflags = dvpe();
0041     set_c0_status(0x100 << MIPS_CPU_RTLX_IRQ);
0042     irq_enable_hazard();
0043     evpe(vpeflags);
0044     local_irq_restore(flags);
0045
0046     for (i = 0; i < RTLX_CHANNELS; i++) {
0047         wake_up(&channel_wqs[i].lx_queue);
0048         wake_up(&channel_wqs[i].rt_queue);
0049     }
0050
0051     return IRQ_HANDLED;
0052 }
0053
0054 static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;
0055
0056 void _interrupt_sp(void)
0057 {
0058     unsigned long flags;
0059
0060     local_irq_save(flags);
0061     dvpe();
0062     settc(1);
0063     write_vpe_c0_cause(read_vpe_c0_cause() | C_SW0);
0064     evpe(EVPE_ENABLE);
0065     local_irq_restore(flags);
0066 }
0067
0068 int __init rtlx_module_init(void)
0069 {
0070     struct device *dev;
0071     int i, err;
0072
0073     if (!cpu_has_mipsmt) {
0074         pr_warn("VPE loader: not a MIPS MT capable processor\n");
0075         return -ENODEV;
0076     }
0077
0078     if (aprp_cpu_index() == 0) {
0079         pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n"
0080             "Pass maxtcs=<n> argument as kernel argument\n");
0081
0082         return -ENODEV;
0083     }
0084
0085     major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops);
0086     if (major < 0) {
0087         pr_err("rtlx_module_init: unable to register device\n");
0088         return major;
0089     }
0090
0091     /* initialise the wait queues */
0092     for (i = 0; i < RTLX_CHANNELS; i++) {
0093         init_waitqueue_head(&channel_wqs[i].rt_queue);
0094         init_waitqueue_head(&channel_wqs[i].lx_queue);
0095         atomic_set(&channel_wqs[i].in_open, 0);
0096         mutex_init(&channel_wqs[i].mutex);
0097
0098         dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
0099                     "%s%d", RTLX_MODULE_NAME, i);
0100         if (IS_ERR(dev)) {
0101             while (i--)
0102                 device_destroy(mt_class, MKDEV(major, i));
0103
0104             err = PTR_ERR(dev);
0105             goto out_chrdev;
0106         }
0107     }
0108
0109     /* set up notifiers */
0110     rtlx_notify.start = rtlx_starting;
0111     rtlx_notify.stop = rtlx_stopping;
0112     vpe_notify(aprp_cpu_index(), &rtlx_notify);
0113
0114     if (cpu_has_vint) {
0115         aprp_hook = rtlx_dispatch;
0116     } else {
0117         pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
0118         err = -ENODEV;
0119         goto out_class;
0120     }
0121
0122     err = request_irq(rtlx_irq_num, rtlx_interrupt, 0, "RTLX", rtlx);
0123     if (err)
0124         goto out_class;
0125
0126     return 0;
0127
0128 out_class:
0129     for (i = 0; i < RTLX_CHANNELS; i++)
0130         device_destroy(mt_class, MKDEV(major, i));
0131 out_chrdev:
0132     unregister_chrdev(major, RTLX_MODULE_NAME);
0133
0134     return err;
0135 }
0136
0137 void __exit rtlx_module_exit(void)
0138 {
0139     int i;
0140
0141     for (i = 0; i < RTLX_CHANNELS; i++)
0142         device_destroy(mt_class, MKDEV(major, i));
0143
0144     unregister_chrdev(major, RTLX_MODULE_NAME);
0145
0146     aprp_hook = NULL;
0147 }