drivers/hv/hv_debugfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Authors:
   4  *   Branden Bonaby <brandonbonaby94@gmail.com>
   5  */
   6
   7 #include <linux/hyperv.h>
   8 #include <linux/debugfs.h>
   9 #include <linux/delay.h>
  10 #include <linux/err.h>
  11
  12 #include "hyperv_vmbus.h"
  13
  14 static struct dentry *hv_debug_root;
  15
  16 static int hv_debugfs_delay_get(void *data, u64 *val)
  17 {
  18         *val = *(u32 *)data;
  19         return 0;
  20 }
  21
  22 static int hv_debugfs_delay_set(void *data, u64 val)
  23 {
  24         if (val > 1000)
  25                 return -EINVAL;
  26         *(u32 *)data = val;
  27         return 0;
  28 }
  29
  30 DEFINE_DEBUGFS_ATTRIBUTE(hv_debugfs_delay_fops, hv_debugfs_delay_get,
  31                          hv_debugfs_delay_set, "%llu\n");
  32
  33 static int hv_debugfs_state_get(void *data, u64 *val)
  34 {
  35         *val = *(bool *)data;
  36         return 0;
  37 }
  38
  39 static int hv_debugfs_state_set(void *data, u64 val)
  40 {
  41         if (val == 1)
  42                 *(bool *)data = true;
  43         else if (val == 0)
  44                 *(bool *)data = false;
  45         else
  46                 return -EINVAL;
  47         return 0;
  48 }
  49
  50 DEFINE_DEBUGFS_ATTRIBUTE(hv_debugfs_state_fops, hv_debugfs_state_get,
  51                          hv_debugfs_state_set, "%llu\n");
  52
  53 /* Setup delay files to store test values */
  54 static int hv_debug_delay_files(struct hv_device *dev, struct dentry *root)
  55 {
  56         struct vmbus_channel *channel = dev->channel;
  57         char *buffer = "fuzz_test_buffer_interrupt_delay";
  58         char *message = "fuzz_test_message_delay";
  59         int *buffer_val = &channel->fuzz_testing_interrupt_delay;
  60         int *message_val = &channel->fuzz_testing_message_delay;
  61         struct dentry *buffer_file, *message_file;
  62
  63         buffer_file = debugfs_create_file(buffer, 0644, root,
  64                                           buffer_val,
  65                                           &hv_debugfs_delay_fops);
  66         if (IS_ERR(buffer_file)) {
  67                 pr_debug("debugfs_hyperv: file %s not created\n", buffer);
  68                 return PTR_ERR(buffer_file);
  69         }
  70
  71         message_file = debugfs_create_file(message, 0644, root,
  72                                            message_val,
  73                                            &hv_debugfs_delay_fops);
  74         if (IS_ERR(message_file)) {
  75                 pr_debug("debugfs_hyperv: file %s not created\n", message);
  76                 return PTR_ERR(message_file);
  77         }
  78
  79         return 0;
  80 }
  81
  82 /* Setup test state value for vmbus device */
  83 static int hv_debug_set_test_state(struct hv_device *dev, struct dentry *root)
  84 {
  85         struct vmbus_channel *channel = dev->channel;
  86         bool *state = &channel->fuzz_testing_state;
  87         char *status = "fuzz_test_state";
  88         struct dentry *test_state;
  89
  90         test_state = debugfs_create_file(status, 0644, root,
  91                                          state,
  92                                          &hv_debugfs_state_fops);
  93         if (IS_ERR(test_state)) {
  94                 pr_debug("debugfs_hyperv: file %s not created\n", status);
  95                 return PTR_ERR(test_state);
  96         }
  97
  98         return 0;
  99 }
 100
 101 /* Bind hv device to a dentry for debugfs */
 102 static void hv_debug_set_dir_dentry(struct hv_device *dev, struct dentry *root)
 103 {
 104         if (hv_debug_root)
 105                 dev->debug_dir = root;
 106 }
 107
 108 /* Create all test dentry's and names for fuzz testing */
 109 int hv_debug_add_dev_dir(struct hv_device *dev)
 110 {
 111         const char *device = dev_name(&dev->device);
 112         char *delay_name = "delay";
 113         struct dentry *delay, *dev_root;
 114         int ret;
 115
 116         if (!IS_ERR(hv_debug_root)) {
 117                 dev_root = debugfs_create_dir(device, hv_debug_root);
 118                 if (IS_ERR(dev_root)) {
 119                         pr_debug("debugfs_hyperv: hyperv/%s/ not created\n",
 120                                  device);
 121                         return PTR_ERR(dev_root);
 122                 }
 123                 hv_debug_set_test_state(dev, dev_root);
 124                 hv_debug_set_dir_dentry(dev, dev_root);
 125                 delay = debugfs_create_dir(delay_name, dev_root);
 126
 127                 if (IS_ERR(delay)) {
 128                         pr_debug("debugfs_hyperv: hyperv/%s/%s/ not created\n",
 129                                  device, delay_name);
 130                         return PTR_ERR(delay);
 131                 }
 132                 ret = hv_debug_delay_files(dev, delay);
 133
 134                 return ret;
 135         }
 136         pr_debug("debugfs_hyperv: hyperv/ not in root debugfs path\n");
 137         return PTR_ERR(hv_debug_root);
 138 }
 139
 140 /* Remove dentry associated with released hv device */
 141 void hv_debug_rm_dev_dir(struct hv_device *dev)
 142 {
 143         if (!IS_ERR(hv_debug_root))
 144                 debugfs_remove_recursive(dev->debug_dir);
 145 }
 146
 147 /* Remove all dentrys associated with vmbus testing */
 148 void hv_debug_rm_all_dir(void)
 149 {
 150         debugfs_remove_recursive(hv_debug_root);
 151 }
 152
 153 /* Delay buffer/message reads on a vmbus channel */
 154 void hv_debug_delay_test(struct vmbus_channel *channel, enum delay delay_type)
 155 {
 156         struct vmbus_channel *test_channel =    channel->primary_channel ?
 157                                                 channel->primary_channel :
 158                                                 channel;
 159         bool state = test_channel->fuzz_testing_state;
 160
 161         if (state) {
 162                 if (delay_type == 0)
 163                         udelay(test_channel->fuzz_testing_interrupt_delay);
 164                 else
 165                         udelay(test_channel->fuzz_testing_message_delay);
 166         }
 167 }
 168
 169 /* Initialize top dentry for vmbus testing */
 170 int hv_debug_init(void)
 171 {
 172         hv_debug_root = debugfs_create_dir("hyperv", NULL);
 173         if (IS_ERR(hv_debug_root)) {
 174                 pr_debug("debugfs_hyperv: hyperv/ not created\n");
 175                 return PTR_ERR(hv_debug_root);
 176         }
 177         return 0;
 178 }