drivers/iommu/omap-iommu-debug.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * omap iommu: debugfs interface
   4  *
   5  * Copyright (C) 2008-2009 Nokia Corporation
   6  *
   7  * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
   8  */
   9
  10 #include <linux/err.h>
  11 #include <linux/io.h>
  12 #include <linux/slab.h>
  13 #include <linux/uaccess.h>
  14 #include <linux/pm_runtime.h>
  15 #include <linux/debugfs.h>
  16 #include <linux/platform_data/iommu-omap.h>
  17
  18 #include "omap-iopgtable.h"
  19 #include "omap-iommu.h"
  20
  21 static DEFINE_MUTEX(iommu_debug_lock);
  22
  23 static struct dentry *iommu_debug_root;
  24
  25 static inline bool is_omap_iommu_detached(struct omap_iommu *obj)
  26 {
  27         return !obj->domain;
  28 }
  29
  30 #define pr_reg(name)                                                    \
  31         do {                                                            \
  32                 ssize_t bytes;                                          \
  33                 const char *str = "%20s: %08x\n";                       \
  34                 const int maxcol = 32;                                  \
  35                 bytes = snprintf(p, maxcol, str, __stringify(name),     \
  36                                  iommu_read_reg(obj, MMU_##name));      \
  37                 p += bytes;                                             \
  38                 len -= bytes;                                           \
  39                 if (len < maxcol)                                       \
  40                         goto out;                                       \
  41         } while (0)
  42
  43 static ssize_t
  44 omap2_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len)
  45 {
  46         char *p = buf;
  47
  48         pr_reg(REVISION);
  49         pr_reg(IRQSTATUS);
  50         pr_reg(IRQENABLE);
  51         pr_reg(WALKING_ST);
  52         pr_reg(CNTL);
  53         pr_reg(FAULT_AD);
  54         pr_reg(TTB);
  55         pr_reg(LOCK);
  56         pr_reg(LD_TLB);
  57         pr_reg(CAM);
  58         pr_reg(RAM);
  59         pr_reg(GFLUSH);
  60         pr_reg(FLUSH_ENTRY);
  61         pr_reg(READ_CAM);
  62         pr_reg(READ_RAM);
  63         pr_reg(EMU_FAULT_AD);
  64 out:
  65         return p - buf;
  66 }
  67
  68 static ssize_t omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf,
  69                                    ssize_t bytes)
  70 {
  71         if (!obj || !buf)
  72                 return -EINVAL;
  73
  74         pm_runtime_get_sync(obj->dev);
  75
  76         bytes = omap2_iommu_dump_ctx(obj, buf, bytes);
  77
  78         pm_runtime_put_sync(obj->dev);
  79
  80         return bytes;
  81 }
  82
  83 static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
  84                                size_t count, loff_t *ppos)
  85 {
  86         struct omap_iommu *obj = file->private_data;
  87         char *p, *buf;
  88         ssize_t bytes;
  89
  90         if (is_omap_iommu_detached(obj))
  91                 return -EPERM;
  92
  93         buf = kmalloc(count, GFP_KERNEL);
  94         if (!buf)
  95                 return -ENOMEM;
  96         p = buf;
  97
  98         mutex_lock(&iommu_debug_lock);
  99
 100         bytes = omap_iommu_dump_ctx(obj, p, count);
 101         bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
 102
 103         mutex_unlock(&iommu_debug_lock);
 104         kfree(buf);
 105
 106         return bytes;
 107 }
 108
 109 static int
 110 __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
 111 {
 112         int i;
 113         struct iotlb_lock saved;
 114         struct cr_regs tmp;
 115         struct cr_regs *p = crs;
 116
 117         pm_runtime_get_sync(obj->dev);
 118         iotlb_lock_get(obj, &saved);
 119
 120         for_each_iotlb_cr(obj, num, i, tmp) {
 121                 if (!iotlb_cr_valid(&tmp))
 122                         continue;
 123                 *p++ = tmp;
 124         }
 125
 126         iotlb_lock_set(obj, &saved);
 127         pm_runtime_put_sync(obj->dev);
 128
 129         return  p - crs;
 130 }
 131
 132 static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
 133                              struct seq_file *s)
 134 {
 135         seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
 136                    (cr->cam & MMU_CAM_P) ? 1 : 0);
 137         return 0;
 138 }
 139
 140 static size_t omap_dump_tlb_entries(struct omap_iommu *obj, struct seq_file *s)
 141 {
 142         int i, num;
 143         struct cr_regs *cr;
 144
 145         num = obj->nr_tlb_entries;
 146
 147         cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
 148         if (!cr)
 149                 return 0;
 150
 151         num = __dump_tlb_entries(obj, cr, num);
 152         for (i = 0; i < num; i++)
 153                 iotlb_dump_cr(obj, cr + i, s);
 154         kfree(cr);
 155
 156         return 0;
 157 }
 158
 159 static int tlb_show(struct seq_file *s, void *data)
 160 {
 161         struct omap_iommu *obj = s->private;
 162
 163         if (is_omap_iommu_detached(obj))
 164                 return -EPERM;
 165
 166         mutex_lock(&iommu_debug_lock);
 167
 168         seq_printf(s, "%8s %8s\n", "cam:", "ram:");
 169         seq_puts(s, "-----------------------------------------\n");
 170         omap_dump_tlb_entries(obj, s);
 171
 172         mutex_unlock(&iommu_debug_lock);
 173
 174         return 0;
 175 }
 176
 177 static void dump_ioptable(struct seq_file *s)
 178 {
 179         int i, j;
 180         u32 da;
 181         u32 *iopgd, *iopte;
 182         struct omap_iommu *obj = s->private;
 183
 184         spin_lock(&obj->page_table_lock);
 185
 186         iopgd = iopgd_offset(obj, 0);
 187         for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
 188                 if (!*iopgd)
 189                         continue;
 190
 191                 if (!(*iopgd & IOPGD_TABLE)) {
 192                         da = i << IOPGD_SHIFT;
 193                         seq_printf(s, "1: 0x%08x 0x%08x\n", da, *iopgd);
 194                         continue;
 195                 }
 196
 197                 iopte = iopte_offset(iopgd, 0);
 198                 for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
 199                         if (!*iopte)
 200                                 continue;
 201
 202                         da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
 203                         seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
 204                 }
 205         }
 206
 207         spin_unlock(&obj->page_table_lock);
 208 }
 209
 210 static int pagetable_show(struct seq_file *s, void *data)
 211 {
 212         struct omap_iommu *obj = s->private;
 213
 214         if (is_omap_iommu_detached(obj))
 215                 return -EPERM;
 216
 217         mutex_lock(&iommu_debug_lock);
 218
 219         seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
 220         seq_puts(s, "--------------------------\n");
 221         dump_ioptable(s);
 222
 223         mutex_unlock(&iommu_debug_lock);
 224
 225         return 0;
 226 }
 227
 228 #define DEBUG_FOPS_RO(name)                                             \
 229         static const struct file_operations name##_fops = {             \
 230                 .open = simple_open,                                    \
 231                 .read = debug_read_##name,                              \
 232                 .llseek = generic_file_llseek,                          \
 233         }
 234
 235 DEBUG_FOPS_RO(regs);
 236 DEFINE_SHOW_ATTRIBUTE(tlb);
 237 DEFINE_SHOW_ATTRIBUTE(pagetable);
 238
 239 void omap_iommu_debugfs_add(struct omap_iommu *obj)
 240 {
 241         struct dentry *d;
 242
 243         if (!iommu_debug_root)
 244                 return;
 245
 246         d = debugfs_create_dir(obj->name, iommu_debug_root);
 247         obj->debug_dir = d;
 248
 249         debugfs_create_u32("nr_tlb_entries", 0400, d, &obj->nr_tlb_entries);
 250         debugfs_create_file("regs", 0400, d, obj, &regs_fops);
 251         debugfs_create_file("tlb", 0400, d, obj, &tlb_fops);
 252         debugfs_create_file("pagetable", 0400, d, obj, &pagetable_fops);
 253 }
 254
 255 void omap_iommu_debugfs_remove(struct omap_iommu *obj)
 256 {
 257         if (!obj->debug_dir)
 258                 return;
 259
 260         debugfs_remove_recursive(obj->debug_dir);
 261 }
 262
 263 void __init omap_iommu_debugfs_init(void)
 264 {
 265         iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
 266 }
 267
 268 void __exit omap_iommu_debugfs_exit(void)
 269 {
 270         debugfs_remove(iommu_debug_root);
 271 }