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 struct irqaction rtlx_irq = { 55 .handler = rtlx_interrupt, 56 .name = "RTLX", 57 }; 58 59 static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ; 60 61 void _interrupt_sp(void) 62 { 63 unsigned long flags; 64 65 local_irq_save(flags); 66 dvpe(); 67 settc(1); 68 write_vpe_c0_cause(read_vpe_c0_cause() | C_SW0); 69 evpe(EVPE_ENABLE); 70 local_irq_restore(flags); 71 } 72 73 int __init rtlx_module_init(void) 74 { 75 struct device *dev; 76 int i, err; 77 78 if (!cpu_has_mipsmt) { 79 pr_warn("VPE loader: not a MIPS MT capable processor\n"); 80 return -ENODEV; 81 } 82 83 if (aprp_cpu_index() == 0) { 84 pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n" 85 "Pass maxtcs=<n> argument as kernel argument\n"); 86 87 return -ENODEV; 88 } 89 90 major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops); 91 if (major < 0) { 92 pr_err("rtlx_module_init: unable to register device\n"); 93 return major; 94 } 95 96 /* initialise the wait queues */ 97 for (i = 0; i < RTLX_CHANNELS; i++) { 98 init_waitqueue_head(&channel_wqs[i].rt_queue); 99 init_waitqueue_head(&channel_wqs[i].lx_queue); 100 atomic_set(&channel_wqs[i].in_open, 0); 101 mutex_init(&channel_wqs[i].mutex); 102 103 dev = device_create(mt_class, NULL, MKDEV(major, i), NULL, 104 "%s%d", RTLX_MODULE_NAME, i); 105 if (IS_ERR(dev)) { 106 while (i--) 107 device_destroy(mt_class, MKDEV(major, i)); 108 109 err = PTR_ERR(dev); 110 goto out_chrdev; 111 } 112 } 113 114 /* set up notifiers */ 115 rtlx_notify.start = rtlx_starting; 116 rtlx_notify.stop = rtlx_stopping; 117 vpe_notify(aprp_cpu_index(), &rtlx_notify); 118 119 if (cpu_has_vint) { 120 aprp_hook = rtlx_dispatch; 121 } else { 122 pr_err("APRP RTLX init on non-vectored-interrupt processor\n"); 123 err = -ENODEV; 124 goto out_class; 125 } 126 127 rtlx_irq.dev_id = rtlx; 128 err = setup_irq(rtlx_irq_num, &rtlx_irq); 129 if (err) 130 goto out_class; 131 132 return 0; 133 134 out_class: 135 for (i = 0; i < RTLX_CHANNELS; i++) 136 device_destroy(mt_class, MKDEV(major, i)); 137 out_chrdev: 138 unregister_chrdev(major, RTLX_MODULE_NAME); 139 140 return err; 141 } 142 143 void __exit rtlx_module_exit(void) 144 { 145 int i; 146 147 for (i = 0; i < RTLX_CHANNELS; i++) 148 device_destroy(mt_class, MKDEV(major, i)); 149 150 unregister_chrdev(major, RTLX_MODULE_NAME); 151 152 aprp_hook = NULL; 153 } 154