drivers/staging/vc04_services/interface/vchiq_arm/vchiq_debugfs.c

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
   2 /*
   3  * Copyright (c) 2014 Raspberry Pi (Trading) Ltd. All rights reserved.
   4  * Copyright (c) 2010-2012 Broadcom. All rights reserved.
   5  */
   6
   7 #include <linux/debugfs.h>
   8 #include "vchiq_core.h"
   9 #include "vchiq_arm.h"
  10 #include "vchiq_debugfs.h"
  11
  12 #ifdef CONFIG_DEBUG_FS
  13
  14 #define DEBUGFS_WRITE_BUF_SIZE 256
  15
  16 /* Global 'vchiq' debugfs and clients entry used by all instances */
  17 static struct dentry *vchiq_dbg_dir;
  18 static struct dentry *vchiq_dbg_clients;
  19
  20 static int debugfs_usecount_show(struct seq_file *f, void *offset)
  21 {
  22         struct vchiq_instance *instance = f->private;
  23         int use_count;
  24
  25         use_count = vchiq_instance_get_use_count(instance);
  26         seq_printf(f, "%d\n", use_count);
  27
  28         return 0;
  29 }
  30 DEFINE_SHOW_ATTRIBUTE(debugfs_usecount);
  31
  32 static int debugfs_trace_show(struct seq_file *f, void *offset)
  33 {
  34         struct vchiq_instance *instance = f->private;
  35         int trace;
  36
  37         trace = vchiq_instance_get_trace(instance);
  38         seq_printf(f, "%s\n", trace ? "Y" : "N");
  39
  40         return 0;
  41 }
  42
  43 static int vchiq_dump_show(struct seq_file *f, void *offset)
  44 {
  45         struct vchiq_state *state = f->private;
  46
  47         vchiq_dump_state(f, state);
  48
  49         return 0;
  50 }
  51 DEFINE_SHOW_ATTRIBUTE(vchiq_dump);
  52
  53 static int debugfs_trace_open(struct inode *inode, struct file *file)
  54 {
  55         return single_open(file, debugfs_trace_show, inode->i_private);
  56 }
  57
  58 static ssize_t debugfs_trace_write(struct file *file,
  59         const char __user *buffer,
  60         size_t count, loff_t *ppos)
  61 {
  62         struct seq_file *f = (struct seq_file *)file->private_data;
  63         struct vchiq_instance *instance = f->private;
  64         char firstchar;
  65
  66         if (copy_from_user(&firstchar, buffer, 1))
  67                 return -EFAULT;
  68
  69         switch (firstchar) {
  70         case 'Y':
  71         case 'y':
  72         case '1':
  73                 vchiq_instance_set_trace(instance, 1);
  74                 break;
  75         case 'N':
  76         case 'n':
  77         case '0':
  78                 vchiq_instance_set_trace(instance, 0);
  79                 break;
  80         default:
  81                 break;
  82         }
  83
  84         *ppos += count;
  85
  86         return count;
  87 }
  88
  89 static const struct file_operations debugfs_trace_fops = {
  90         .owner          = THIS_MODULE,
  91         .open           = debugfs_trace_open,
  92         .write          = debugfs_trace_write,
  93         .read           = seq_read,
  94         .llseek         = seq_lseek,
  95         .release        = single_release,
  96 };
  97
  98 /* add an instance (process) to the debugfs entries */
  99 void vchiq_debugfs_add_instance(struct vchiq_instance *instance)
 100 {
 101         char pidstr[16];
 102         struct dentry *top;
 103
 104         snprintf(pidstr, sizeof(pidstr), "%d",
 105                  vchiq_instance_get_pid(instance));
 106
 107         top = debugfs_create_dir(pidstr, vchiq_dbg_clients);
 108
 109         debugfs_create_file("use_count", 0444, top, instance,
 110                             &debugfs_usecount_fops);
 111         debugfs_create_file("trace", 0644, top, instance, &debugfs_trace_fops);
 112
 113         vchiq_instance_get_debugfs_node(instance)->dentry = top;
 114 }
 115
 116 void vchiq_debugfs_remove_instance(struct vchiq_instance *instance)
 117 {
 118         struct vchiq_debugfs_node *node =
 119                                 vchiq_instance_get_debugfs_node(instance);
 120
 121         debugfs_remove_recursive(node->dentry);
 122 }
 123
 124 void vchiq_debugfs_init(struct vchiq_state *state)
 125 {
 126         vchiq_dbg_dir = debugfs_create_dir("vchiq", NULL);
 127         vchiq_dbg_clients = debugfs_create_dir("clients", vchiq_dbg_dir);
 128
 129         debugfs_create_file("state", S_IFREG | 0444, vchiq_dbg_dir, state,
 130                             &vchiq_dump_fops);
 131 }
 132
 133 /* remove all the debugfs entries */
 134 void vchiq_debugfs_deinit(void)
 135 {
 136         debugfs_remove_recursive(vchiq_dbg_dir);
 137 }
 138
 139 #else /* CONFIG_DEBUG_FS */
 140
 141 void vchiq_debugfs_init(void)
 142 {
 143 }
 144
 145 void vchiq_debugfs_deinit(void)
 146 {
 147 }
 148
 149 void vchiq_debugfs_add_instance(struct vchiq_instance *instance)
 150 {
 151 }
 152
 153 void vchiq_debugfs_remove_instance(struct vchiq_instance *instance)
 154 {
 155 }
 156
 157 #endif /* CONFIG_DEBUG_FS */