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         bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
 105
 106         mutex_unlock(&iommu_debug_lock);
 107         kfree(buf);
 108
 109         return bytes;
 110 }
 111
 112 static int
 113 __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
 114 {
 115         int i;
 116         struct iotlb_lock saved;
 117         struct cr_regs tmp;
 118         struct cr_regs *p = crs;
 119
 120         pm_runtime_get_sync(obj->dev);
 121         iotlb_lock_get(obj, &saved);
 122
 123         for_each_iotlb_cr(obj, num, i, tmp) {
 124                 if (!iotlb_cr_valid(&tmp))
 125                         continue;
 126                 *p++ = tmp;
 127         }
 128
 129         iotlb_lock_set(obj, &saved);
 130         pm_runtime_put_sync(obj->dev);
 131
 132         return  p - crs;
 133 }
 134
 135 static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
 136                              char *buf)
 137 {
 138         char *p = buf;
 139
 140         /* FIXME: Need more detail analysis of cam/ram */
 141         p += sprintf(p, "%08x %08x %01x\n", cr->cam, cr->ram,
 142                                         (cr->cam & MMU_CAM_P) ? 1 : 0);
 143
 144         return p - buf;
 145 }
 146
 147 static size_t omap_dump_tlb_entries(struct omap_iommu *obj, char *buf,
 148                                     ssize_t bytes)
 149 {
 150         int i, num;
 151         struct cr_regs *cr;
 152         char *p = buf;
 153
 154         num = bytes / sizeof(*cr);
 155         num = min(obj->nr_tlb_entries, num);
 156
 157         cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
 158         if (!cr)
 159                 return 0;
 160
 161         num = __dump_tlb_entries(obj, cr, num);
 162         for (i = 0; i < num; i++)
 163                 p += iotlb_dump_cr(obj, cr + i, p);
 164         kfree(cr);
 165
 166         return p - buf;
 167 }
 168
 169 static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
 170                               size_t count, loff_t *ppos)
 171 {
 172         struct omap_iommu *obj = file->private_data;
 173         char *p, *buf;
 174         ssize_t bytes, rest;
 175
 176         if (is_omap_iommu_detached(obj))
 177                 return -EPERM;
 178
 179         buf = kmalloc(count, GFP_KERNEL);
 180         if (!buf)
 181                 return -ENOMEM;
 182         p = buf;
 183
 184         mutex_lock(&iommu_debug_lock);
 185
 186         p += sprintf(p, "%8s %8s\n", "cam:", "ram:");
 187         p += sprintf(p, "-----------------------------------------\n");
 188         rest = count - (p - buf);
 189         p += omap_dump_tlb_entries(obj, p, rest);
 190
 191         bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
 192
 193         mutex_unlock(&iommu_debug_lock);
 194         kfree(buf);
 195
 196         return bytes;
 197 }
 198
 199 static void dump_ioptable(struct seq_file *s)
 200 {
 201         int i, j;
 202         u32 da;
 203         u32 *iopgd, *iopte;
 204         struct omap_iommu *obj = s->private;
 205
 206         spin_lock(&obj->page_table_lock);
 207
 208         iopgd = iopgd_offset(obj, 0);
 209         for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
 210                 if (!*iopgd)
 211                         continue;
 212
 213                 if (!(*iopgd & IOPGD_TABLE)) {
 214                         da = i << IOPGD_SHIFT;
 215                         seq_printf(s, "1: 0x%08x 0x%08x\n", da, *iopgd);
 216                         continue;
 217                 }
 218
 219                 iopte = iopte_offset(iopgd, 0);
 220                 for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
 221                         if (!*iopte)
 222                                 continue;
 223
 224                         da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
 225                         seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
 226                 }
 227         }
 228
 229         spin_unlock(&obj->page_table_lock);
 230 }
 231
 232 static int debug_read_pagetable(struct seq_file *s, void *data)
 233 {
 234         struct omap_iommu *obj = s->private;
 235
 236         if (is_omap_iommu_detached(obj))
 237                 return -EPERM;
 238
 239         mutex_lock(&iommu_debug_lock);
 240
 241         seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
 242         seq_puts(s, "--------------------------\n");
 243         dump_ioptable(s);
 244
 245         mutex_unlock(&iommu_debug_lock);
 246
 247         return 0;
 248 }
 249
 250 #define DEBUG_SEQ_FOPS_RO(name)                                                \
 251         static int debug_open_##name(struct inode *inode, struct file *file)   \
 252         {                                                                      \
 253                 return single_open(file, debug_read_##name, inode->i_private); \
 254         }                                                                      \
 255                                                                                \
 256         static const struct file_operations debug_##name##_fops = {            \
 257                 .open           = debug_open_##name,                           \
 258                 .read           = seq_read,                                    \
 259                 .llseek         = seq_lseek,                                   \
 260                 .release        = single_release,                              \
 261         }
 262
 263 #define DEBUG_FOPS_RO(name)                                             \
 264         static const struct file_operations debug_##name##_fops = {     \
 265                 .open = simple_open,                                    \
 266                 .read = debug_read_##name,                              \
 267                 .llseek = generic_file_llseek,                          \
 268         }
 269
 270 DEBUG_FOPS_RO(regs);
 271 DEBUG_FOPS_RO(tlb);
 272 DEBUG_SEQ_FOPS_RO(pagetable);
 273
 274 #define __DEBUG_ADD_FILE(attr, mode)                                    \
 275         {                                                               \
 276                 struct dentry *dent;                                    \
 277                 dent = debugfs_create_file(#attr, mode, obj->debug_dir, \
 278                                            obj, &debug_##attr##_fops);  \
 279                 if (!dent)                                              \
 280                         goto err;                                       \
 281         }
 282
 283 #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
 284
 285 void omap_iommu_debugfs_add(struct omap_iommu *obj)
 286 {
 287         struct dentry *d;
 288
 289         if (!iommu_debug_root)
 290                 return;
 291
 292         obj->debug_dir = debugfs_create_dir(obj->name, iommu_debug_root);
 293         if (!obj->debug_dir)
 294                 return;
 295
 296         d = debugfs_create_u8("nr_tlb_entries", 0400, obj->debug_dir,
 297                               (u8 *)&obj->nr_tlb_entries);
 298         if (!d)
 299                 return;
 300
 301         DEBUG_ADD_FILE_RO(regs);
 302         DEBUG_ADD_FILE_RO(tlb);
 303         DEBUG_ADD_FILE_RO(pagetable);
 304
 305         return;
 306
 307 err:
 308         debugfs_remove_recursive(obj->debug_dir);
 309 }
 310
 311 void omap_iommu_debugfs_remove(struct omap_iommu *obj)
 312 {
 313         if (!obj->debug_dir)
 314                 return;
 315
 316         debugfs_remove_recursive(obj->debug_dir);
 317 }
 318
 319 void __init omap_iommu_debugfs_init(void)
 320 {
 321         iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
 322         if (!iommu_debug_root)
 323                 pr_err("can't create debugfs dir\n");
 324 }
 325
 326 void __exit omap_iommu_debugfs_exit(void)
 327 {
 328         debugfs_remove(iommu_debug_root);
 329 }