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 /* Ought not to be strictly necessary for SMTC builds */ 40 local_irq_save(flags); 41 vpeflags = dvpe(); 42 set_c0_status(0x100 << MIPS_CPU_RTLX_IRQ); 43 irq_enable_hazard(); 44 evpe(vpeflags); 45 local_irq_restore(flags); 46 47 for (i = 0; i < RTLX_CHANNELS; i++) { 48 wake_up(&channel_wqs[i].lx_queue); 49 wake_up(&channel_wqs[i].rt_queue); 50 } 51 52 return IRQ_HANDLED; 53 } 54 55 static struct irqaction rtlx_irq = { 56 .handler = rtlx_interrupt, 57 .name = "RTLX", 58 }; 59 60 static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ; 61 62 void _interrupt_sp(void) 63 { 64 unsigned long flags; 65 66 local_irq_save(flags); 67 dvpe(); 68 settc(1); 69 write_vpe_c0_cause(read_vpe_c0_cause() | C_SW0); 70 evpe(EVPE_ENABLE); 71 local_irq_restore(flags); 72 } 73 74 int __init rtlx_module_init(void) 75 { 76 struct device *dev; 77 int i, err; 78 79 if (!cpu_has_mipsmt) { 80 pr_warn("VPE loader: not a MIPS MT capable processor\n"); 81 return -ENODEV; 82 } 83 84 if (aprp_cpu_index() == 0) { 85 pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n" 86 "Pass maxtcs=<n> argument as kernel argument\n"); 87 88 return -ENODEV; 89 } 90 91 major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops); 92 if (major < 0) { 93 pr_err("rtlx_module_init: unable to register device\n"); 94 return major; 95 } 96 97 /* initialise the wait queues */ 98 for (i = 0; i < RTLX_CHANNELS; i++) { 99 init_waitqueue_head(&channel_wqs[i].rt_queue); 100 init_waitqueue_head(&channel_wqs[i].lx_queue); 101 atomic_set(&channel_wqs[i].in_open, 0); 102 mutex_init(&channel_wqs[i].mutex); 103 104 dev = device_create(mt_class, NULL, MKDEV(major, i), NULL, 105 "%s%d", RTLX_MODULE_NAME, i); 106 if (IS_ERR(dev)) { 107 err = PTR_ERR(dev); 108 goto out_chrdev; 109 } 110 } 111 112 /* set up notifiers */ 113 rtlx_notify.start = rtlx_starting; 114 rtlx_notify.stop = rtlx_stopping; 115 vpe_notify(aprp_cpu_index(), &rtlx_notify); 116 117 if (cpu_has_vint) { 118 aprp_hook = rtlx_dispatch; 119 } else { 120 pr_err("APRP RTLX init on non-vectored-interrupt processor\n"); 121 err = -ENODEV; 122 goto out_class; 123 } 124 125 rtlx_irq.dev_id = rtlx; 126 err = setup_irq(rtlx_irq_num, &rtlx_irq); 127 if (err) 128 goto out_class; 129 130 return 0; 131 132 out_class: 133 for (i = 0; i < RTLX_CHANNELS; i++) 134 device_destroy(mt_class, MKDEV(major, i)); 135 out_chrdev: 136 unregister_chrdev(major, RTLX_MODULE_NAME); 137 138 return err; 139 } 140 141 void __exit rtlx_module_exit(void) 142 { 143 int i; 144 145 for (i = 0; i < RTLX_CHANNELS; i++) 146 device_destroy(mt_class, MKDEV(major, i)); 147 148 unregister_chrdev(major, RTLX_MODULE_NAME); 149 150 aprp_hook = NULL; 151 } 152