| 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 | |
| 21 | static int major; |
| 22 | |
| 23 | static 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 | */ |
| 33 | static 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 | |
| 54 | static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ; |
| 55 | |
| 56 | void _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 | |
| 68 | int __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 | |
| 128 | out_class: |
| 129 | for (i = 0; i < RTLX_CHANNELS; i++) |
| 130 | device_destroy(&mt_class, MKDEV(major, i)); |
| 131 | out_chrdev: |
| 132 | unregister_chrdev(major, RTLX_MODULE_NAME); |
| 133 | |
| 134 | return err; |
| 135 | } |
| 136 | |
| 137 | void __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 | } |