drivers/iommu/omap-iommu-debug.c

   1 /*
   2  * omap iommu: debugfs interface
   3  *
   4  * Copyright (C) 2008-2009 Nokia Corporation
   5  *
   6  * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/err.h>
  14 #include <linux/io.h>
  15 #include <linux/slab.h>
  16 #include <linux/uaccess.h>
  17 #include <linux/debugfs.h>
  18 #include <linux/platform_data/iommu-omap.h>
  19
  20 #include "omap-iopgtable.h"
  21 #include "omap-iommu.h"
  22
  23 static DEFINE_MUTEX(iommu_debug_lock);
  24
  25 static struct dentry *iommu_debug_root;
  26
  27 static inline bool is_omap_iommu_detached(struct omap_iommu *obj)
  28 {
  29         return !obj->domain;
  30 }
  31
  32 static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
  33                                size_t count, loff_t *ppos)
  34 {
  35         struct omap_iommu *obj = file->private_data;
  36         char *p, *buf;
  37         ssize_t bytes;
  38
  39         if (is_omap_iommu_detached(obj))
  40                 return -EPERM;
  41
  42         buf = kmalloc(count, GFP_KERNEL);
  43         if (!buf)
  44                 return -ENOMEM;
  45         p = buf;
  46
  47         mutex_lock(&iommu_debug_lock);
  48
  49         bytes = omap_iommu_dump_ctx(obj, p, count);
  50         bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
  51
  52         mutex_unlock(&iommu_debug_lock);
  53         kfree(buf);
  54
  55         return bytes;
  56 }
  57
  58 static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
  59                               size_t count, loff_t *ppos)
  60 {
  61         struct omap_iommu *obj = file->private_data;
  62         char *p, *buf;
  63         ssize_t bytes, rest;
  64
  65         if (is_omap_iommu_detached(obj))
  66                 return -EPERM;
  67
  68         buf = kmalloc(count, GFP_KERNEL);
  69         if (!buf)
  70                 return -ENOMEM;
  71         p = buf;
  72
  73         mutex_lock(&iommu_debug_lock);
  74
  75         p += sprintf(p, "%8s %8s\n", "cam:", "ram:");
  76         p += sprintf(p, "-----------------------------------------\n");
  77         rest = count - (p - buf);
  78         p += omap_dump_tlb_entries(obj, p, rest);
  79
  80         bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
  81
  82         mutex_unlock(&iommu_debug_lock);
  83         kfree(buf);
  84
  85         return bytes;
  86 }
  87
  88 static void dump_ioptable(struct seq_file *s)
  89 {
  90         int i, j;
  91         u32 da;
  92         u32 *iopgd, *iopte;
  93         struct omap_iommu *obj = s->private;
  94
  95         spin_lock(&obj->page_table_lock);
  96
  97         iopgd = iopgd_offset(obj, 0);
  98         for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
  99                 if (!*iopgd)
 100                         continue;
 101
 102                 if (!(*iopgd & IOPGD_TABLE)) {
 103                         da = i << IOPGD_SHIFT;
 104                         seq_printf(s, "1: 0x%08x 0x%08x\n", da, *iopgd);
 105                         continue;
 106                 }
 107
 108                 iopte = iopte_offset(iopgd, 0);
 109                 for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
 110                         if (!*iopte)
 111                                 continue;
 112
 113                         da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
 114                         seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
 115                 }
 116         }
 117
 118         spin_unlock(&obj->page_table_lock);
 119 }
 120
 121 static int debug_read_pagetable(struct seq_file *s, void *data)
 122 {
 123         struct omap_iommu *obj = s->private;
 124
 125         if (is_omap_iommu_detached(obj))
 126                 return -EPERM;
 127
 128         mutex_lock(&iommu_debug_lock);
 129
 130         seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
 131         seq_puts(s, "--------------------------\n");
 132         dump_ioptable(s);
 133
 134         mutex_unlock(&iommu_debug_lock);
 135
 136         return 0;
 137 }
 138
 139 #define DEBUG_SEQ_FOPS_RO(name)                                                \
 140         static int debug_open_##name(struct inode *inode, struct file *file)   \
 141         {                                                                      \
 142                 return single_open(file, debug_read_##name, inode->i_private); \
 143         }                                                                      \
 144                                                                                \
 145         static const struct file_operations debug_##name##_fops = {            \
 146                 .open           = debug_open_##name,                           \
 147                 .read           = seq_read,                                    \
 148                 .llseek         = seq_lseek,                                   \
 149                 .release        = single_release,                              \
 150         }
 151
 152 #define DEBUG_FOPS_RO(name)                                             \
 153         static const struct file_operations debug_##name##_fops = {     \
 154                 .open = simple_open,                                    \
 155                 .read = debug_read_##name,                              \
 156                 .llseek = generic_file_llseek,                          \
 157         };
 158
 159 DEBUG_FOPS_RO(regs);
 160 DEBUG_FOPS_RO(tlb);
 161 DEBUG_SEQ_FOPS_RO(pagetable);
 162
 163 #define __DEBUG_ADD_FILE(attr, mode)                                    \
 164         {                                                               \
 165                 struct dentry *dent;                                    \
 166                 dent = debugfs_create_file(#attr, mode, obj->debug_dir, \
 167                                            obj, &debug_##attr##_fops);  \
 168                 if (!dent)                                              \
 169                         goto err;                                       \
 170         }
 171
 172 #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
 173
 174 void omap_iommu_debugfs_add(struct omap_iommu *obj)
 175 {
 176         struct dentry *d;
 177
 178         if (!iommu_debug_root)
 179                 return;
 180
 181         obj->debug_dir = debugfs_create_dir(obj->name, iommu_debug_root);
 182         if (!obj->debug_dir)
 183                 return;
 184
 185         d = debugfs_create_u8("nr_tlb_entries", 0400, obj->debug_dir,
 186                               (u8 *)&obj->nr_tlb_entries);
 187         if (!d)
 188                 return;
 189
 190         DEBUG_ADD_FILE_RO(regs);
 191         DEBUG_ADD_FILE_RO(tlb);
 192         DEBUG_ADD_FILE_RO(pagetable);
 193
 194         return;
 195
 196 err:
 197         debugfs_remove_recursive(obj->debug_dir);
 198 }
 199
 200 void omap_iommu_debugfs_remove(struct omap_iommu *obj)
 201 {
 202         if (!obj->debug_dir)
 203                 return;
 204
 205         debugfs_remove_recursive(obj->debug_dir);
 206 }
 207
 208 void __init omap_iommu_debugfs_init(void)
 209 {
 210         iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
 211         if (!iommu_debug_root)
 212                 pr_err("can't create debugfs dir\n");
 213 }
 214
 215 void __exit omap_iommu_debugfs_exit(void)
 216 {
 217         debugfs_remove(iommu_debug_root);
 218 }