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                              struct seq_file *s)
 137 {
 138         seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
 139                    (cr->cam & MMU_CAM_P) ? 1 : 0);
 140         return 0;
 141 }
 142
 143 static size_t omap_dump_tlb_entries(struct omap_iommu *obj, struct seq_file *s)
 144 {
 145         int i, num;
 146         struct cr_regs *cr;
 147
 148         num = obj->nr_tlb_entries;
 149
 150         cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
 151         if (!cr)
 152                 return 0;
 153
 154         num = __dump_tlb_entries(obj, cr, num);
 155         for (i = 0; i < num; i++)
 156                 iotlb_dump_cr(obj, cr + i, s);
 157         kfree(cr);
 158
 159         return 0;
 160 }
 161
 162 static int tlb_show(struct seq_file *s, void *data)
 163 {
 164         struct omap_iommu *obj = s->private;
 165
 166         if (is_omap_iommu_detached(obj))
 167                 return -EPERM;
 168
 169         mutex_lock(&iommu_debug_lock);
 170
 171         seq_printf(s, "%8s %8s\n", "cam:", "ram:");
 172         seq_puts(s, "-----------------------------------------\n");
 173         omap_dump_tlb_entries(obj, s);
 174
 175         mutex_unlock(&iommu_debug_lock);
 176
 177         return 0;
 178 }
 179
 180 static void dump_ioptable(struct seq_file *s)
 181 {
 182         int i, j;
 183         u32 da;
 184         u32 *iopgd, *iopte;
 185         struct omap_iommu *obj = s->private;
 186
 187         spin_lock(&obj->page_table_lock);
 188
 189         iopgd = iopgd_offset(obj, 0);
 190         for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
 191                 if (!*iopgd)
 192                         continue;
 193
 194                 if (!(*iopgd & IOPGD_TABLE)) {
 195                         da = i << IOPGD_SHIFT;
 196                         seq_printf(s, "1: 0x%08x 0x%08x\n", da, *iopgd);
 197                         continue;
 198                 }
 199
 200                 iopte = iopte_offset(iopgd, 0);
 201                 for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
 202                         if (!*iopte)
 203                                 continue;
 204
 205                         da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
 206                         seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
 207                 }
 208         }
 209
 210         spin_unlock(&obj->page_table_lock);
 211 }
 212
 213 static int pagetable_show(struct seq_file *s, void *data)
 214 {
 215         struct omap_iommu *obj = s->private;
 216
 217         if (is_omap_iommu_detached(obj))
 218                 return -EPERM;
 219
 220         mutex_lock(&iommu_debug_lock);
 221
 222         seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
 223         seq_puts(s, "--------------------------\n");
 224         dump_ioptable(s);
 225
 226         mutex_unlock(&iommu_debug_lock);
 227
 228         return 0;
 229 }
 230
 231 #define DEBUG_FOPS_RO(name)                                             \
 232         static const struct file_operations name##_fops = {             \
 233                 .open = simple_open,                                    \
 234                 .read = debug_read_##name,                              \
 235                 .llseek = generic_file_llseek,                          \
 236         }
 237
 238 DEBUG_FOPS_RO(regs);
 239 DEFINE_SHOW_ATTRIBUTE(tlb);
 240 DEFINE_SHOW_ATTRIBUTE(pagetable);
 241
 242 #define __DEBUG_ADD_FILE(attr, mode)                                    \
 243         {                                                               \
 244                 struct dentry *dent;                                    \
 245                 dent = debugfs_create_file(#attr, mode, obj->debug_dir, \
 246                                            obj, &attr##_fops);          \
 247                 if (!dent)                                              \
 248                         goto err;                                       \
 249         }
 250
 251 #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
 252
 253 void omap_iommu_debugfs_add(struct omap_iommu *obj)
 254 {
 255         struct dentry *d;
 256
 257         if (!iommu_debug_root)
 258                 return;
 259
 260         obj->debug_dir = debugfs_create_dir(obj->name, iommu_debug_root);
 261         if (!obj->debug_dir)
 262                 return;
 263
 264         d = debugfs_create_u32("nr_tlb_entries", 0400, obj->debug_dir,
 265                                &obj->nr_tlb_entries);
 266         if (!d)
 267                 return;
 268
 269         DEBUG_ADD_FILE_RO(regs);
 270         DEBUG_ADD_FILE_RO(tlb);
 271         DEBUG_ADD_FILE_RO(pagetable);
 272
 273         return;
 274
 275 err:
 276         debugfs_remove_recursive(obj->debug_dir);
 277 }
 278
 279 void omap_iommu_debugfs_remove(struct omap_iommu *obj)
 280 {
 281         if (!obj->debug_dir)
 282                 return;
 283
 284         debugfs_remove_recursive(obj->debug_dir);
 285 }
 286
 287 void __init omap_iommu_debugfs_init(void)
 288 {
 289         iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
 290         if (!iommu_debug_root)
 291                 pr_err("can't create debugfs dir\n");
 292 }
 293
 294 void __exit omap_iommu_debugfs_exit(void)
 295 {
 296         debugfs_remove(iommu_debug_root);
 297 }