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/pm_runtime.h>
  18 #include <linux/debugfs.h>
  19 #include <linux/platform_data/iommu-omap.h>
  20
  21 #include "omap-iopgtable.h"
  22 #include "omap-iommu.h"
  23
  24 static DEFINE_MUTEX(iommu_debug_lock);
  25
  26 static struct dentry *iommu_debug_root;
  27
  28 static inline bool is_omap_iommu_detached(struct omap_iommu *obj)
  29 {
  30         return !obj->domain;
  31 }
  32
  33 #define pr_reg(name)                                                    \
  34         do {                                                            \
  35                 ssize_t bytes;                                          \
  36                 const char *str = "%20s: %08x\n";                       \
  37                 const int maxcol = 32;                                  \
  38                 bytes = snprintf(p, maxcol, str, __stringify(name),     \
  39                                  iommu_read_reg(obj, MMU_##name));      \
  40                 p += bytes;                                             \
  41                 len -= bytes;                                           \
  42                 if (len < maxcol)                                       \
  43                         goto out;                                       \
  44         } while (0)
  45
  46 static ssize_t
  47 omap2_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len)
  48 {
  49         char *p = buf;
  50
  51         pr_reg(REVISION);
  52         pr_reg(IRQSTATUS);
  53         pr_reg(IRQENABLE);
  54         pr_reg(WALKING_ST);
  55         pr_reg(CNTL);
  56         pr_reg(FAULT_AD);
  57         pr_reg(TTB);
  58         pr_reg(LOCK);
  59         pr_reg(LD_TLB);
  60         pr_reg(CAM);
  61         pr_reg(RAM);
  62         pr_reg(GFLUSH);
  63         pr_reg(FLUSH_ENTRY);
  64         pr_reg(READ_CAM);
  65         pr_reg(READ_RAM);
  66         pr_reg(EMU_FAULT_AD);
  67 out:
  68         return p - buf;
  69 }
  70
  71 static ssize_t omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf,
  72                                    ssize_t bytes)
  73 {
  74         if (!obj || !buf)
  75                 return -EINVAL;
  76
  77         pm_runtime_get_sync(obj->dev);
  78
  79         bytes = omap2_iommu_dump_ctx(obj, buf, bytes);
  80
  81         pm_runtime_put_sync(obj->dev);
  82
  83         return bytes;
  84 }
  85
  86 static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
  87                                size_t count, loff_t *ppos)
  88 {
  89         struct omap_iommu *obj = file->private_data;
  90         char *p, *buf;
  91         ssize_t bytes;
  92
  93         if (is_omap_iommu_detached(obj))
  94                 return -EPERM;
  95
  96         buf = kmalloc(count, GFP_KERNEL);
  97         if (!buf)
  98                 return -ENOMEM;
  99         p = buf;
 100
 101         mutex_lock(&iommu_debug_lock);
 102
 103         bytes = omap_iommu_dump_ctx(obj, p, count);
 104         if (bytes < 0)
 105                 goto err;
 106         bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
 107
 108 err:
 109         mutex_unlock(&iommu_debug_lock);
 110         kfree(buf);
 111
 112         return bytes;
 113 }
 114
 115 static int
 116 __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
 117 {
 118         int i;
 119         struct iotlb_lock saved;
 120         struct cr_regs tmp;
 121         struct cr_regs *p = crs;
 122
 123         pm_runtime_get_sync(obj->dev);
 124         iotlb_lock_get(obj, &saved);
 125
 126         for_each_iotlb_cr(obj, num, i, tmp) {
 127                 if (!iotlb_cr_valid(&tmp))
 128                         continue;
 129                 *p++ = tmp;
 130         }
 131
 132         iotlb_lock_set(obj, &saved);
 133         pm_runtime_put_sync(obj->dev);
 134
 135         return  p - crs;
 136 }
 137
 138 static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
 139                              struct seq_file *s)
 140 {
 141         seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
 142                           (cr->cam & MMU_CAM_P) ? 1 : 0);
 143         return 0;
 144 }
 145
 146 static size_t omap_dump_tlb_entries(struct omap_iommu *obj, struct seq_file *s)
 147 {
 148         int i, num;
 149         struct cr_regs *cr;
 150
 151         num = obj->nr_tlb_entries;
 152
 153         cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
 154         if (!cr)
 155                 return 0;
 156
 157         num = __dump_tlb_entries(obj, cr, num);
 158         for (i = 0; i < num; i++)
 159                 iotlb_dump_cr(obj, cr + i, s);
 160         kfree(cr);
 161
 162         return 0;
 163 }
 164
 165 static int debug_read_tlb(struct seq_file *s, void *data)
 166 {
 167         struct omap_iommu *obj = s->private;
 168
 169         if (is_omap_iommu_detached(obj))
 170                 return -EPERM;
 171
 172         mutex_lock(&iommu_debug_lock);
 173
 174         seq_printf(s, "%8s %8s\n", "cam:", "ram:");
 175         seq_puts(s, "-----------------------------------------\n");
 176         omap_dump_tlb_entries(obj, s);
 177
 178         mutex_unlock(&iommu_debug_lock);
 179
 180         return 0;
 181 }
 182
 183 static void dump_ioptable(struct seq_file *s)
 184 {
 185         int i, j;
 186         u32 da;
 187         u32 *iopgd, *iopte;
 188         struct omap_iommu *obj = s->private;
 189
 190         spin_lock(&obj->page_table_lock);
 191
 192         iopgd = iopgd_offset(obj, 0);
 193         for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
 194                 if (!*iopgd)
 195                         continue;
 196
 197                 if (!(*iopgd & IOPGD_TABLE)) {
 198                         da = i << IOPGD_SHIFT;
 199                         seq_printf(s, "1: 0x%08x 0x%08x\n", da, *iopgd);
 200                         continue;
 201                 }
 202
 203                 iopte = iopte_offset(iopgd, 0);
 204                 for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
 205                         if (!*iopte)
 206                                 continue;
 207
 208                         da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
 209                         seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
 210                 }
 211         }
 212
 213         spin_unlock(&obj->page_table_lock);
 214 }
 215
 216 static int debug_read_pagetable(struct seq_file *s, void *data)
 217 {
 218         struct omap_iommu *obj = s->private;
 219
 220         if (is_omap_iommu_detached(obj))
 221                 return -EPERM;
 222
 223         mutex_lock(&iommu_debug_lock);
 224
 225         seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
 226         seq_puts(s, "--------------------------\n");
 227         dump_ioptable(s);
 228
 229         mutex_unlock(&iommu_debug_lock);
 230
 231         return 0;
 232 }
 233
 234 #define DEBUG_SEQ_FOPS_RO(name)                                                \
 235         static int debug_open_##name(struct inode *inode, struct file *file)   \
 236         {                                                                      \
 237                 return single_open(file, debug_read_##name, inode->i_private); \
 238         }                                                                      \
 239                                                                                \
 240         static const struct file_operations debug_##name##_fops = {            \
 241                 .open           = debug_open_##name,                           \
 242                 .read           = seq_read,                                    \
 243                 .llseek         = seq_lseek,                                   \
 244                 .release        = single_release,                              \
 245         }
 246
 247 #define DEBUG_FOPS_RO(name)                                             \
 248         static const struct file_operations debug_##name##_fops = {     \
 249                 .open = simple_open,                                    \
 250                 .read = debug_read_##name,                              \
 251                 .llseek = generic_file_llseek,                          \
 252         }
 253
 254 DEBUG_FOPS_RO(regs);
 255 DEBUG_SEQ_FOPS_RO(tlb);
 256 DEBUG_SEQ_FOPS_RO(pagetable);
 257
 258 #define __DEBUG_ADD_FILE(attr, mode)                                    \
 259         {                                                               \
 260                 struct dentry *dent;                                    \
 261                 dent = debugfs_create_file(#attr, mode, obj->debug_dir, \
 262                                            obj, &debug_##attr##_fops);  \
 263                 if (!dent)                                              \
 264                         goto err;                                       \
 265         }
 266
 267 #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
 268
 269 void omap_iommu_debugfs_add(struct omap_iommu *obj)
 270 {
 271         struct dentry *d;
 272
 273         if (!iommu_debug_root)
 274                 return;
 275
 276         obj->debug_dir = debugfs_create_dir(obj->name, iommu_debug_root);
 277         if (!obj->debug_dir)
 278                 return;
 279
 280         d = debugfs_create_u8("nr_tlb_entries", 0400, obj->debug_dir,
 281                               (u8 *)&obj->nr_tlb_entries);
 282         if (!d)
 283                 return;
 284
 285         DEBUG_ADD_FILE_RO(regs);
 286         DEBUG_ADD_FILE_RO(tlb);
 287         DEBUG_ADD_FILE_RO(pagetable);
 288
 289         return;
 290
 291 err:
 292         debugfs_remove_recursive(obj->debug_dir);
 293 }
 294
 295 void omap_iommu_debugfs_remove(struct omap_iommu *obj)
 296 {
 297         if (!obj->debug_dir)
 298                 return;
 299
 300         debugfs_remove_recursive(obj->debug_dir);
 301 }
 302
 303 void __init omap_iommu_debugfs_init(void)
 304 {
 305         iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
 306         if (!iommu_debug_root)
 307                 pr_err("can't create debugfs dir\n");
 308 }
 309
 310 void __exit omap_iommu_debugfs_exit(void)
 311 {
 312         debugfs_remove(iommu_debug_root);
 313 }