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                 if (len < maxcol)                                       \
  36                         goto out;                                       \
  37                 bytes = scnprintf(p, maxcol, str, __stringify(name),    \
  38                                  iommu_read_reg(obj, MMU_##name));      \
  39                 p += bytes;                                             \
  40                 len -= bytes;                                           \
  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         if (bytes < 0)
 102                 goto err;
 103         bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
 104
 105 err:
 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 void omap_iommu_debugfs_add(struct omap_iommu *obj)
 243 {
 244         struct dentry *d;
 245
 246         if (!iommu_debug_root)
 247                 return;
 248
 249         d = debugfs_create_dir(obj->name, iommu_debug_root);
 250         obj->debug_dir = d;
 251
 252         debugfs_create_u32("nr_tlb_entries", 0400, d, &obj->nr_tlb_entries);
 253         debugfs_create_file("regs", 0400, d, obj, &regs_fops);
 254         debugfs_create_file("tlb", 0400, d, obj, &tlb_fops);
 255         debugfs_create_file("pagetable", 0400, d, obj, &pagetable_fops);
 256 }
 257
 258 void omap_iommu_debugfs_remove(struct omap_iommu *obj)
 259 {
 260         if (!obj->debug_dir)
 261                 return;
 262
 263         debugfs_remove_recursive(obj->debug_dir);
 264 }
 265
 266 void __init omap_iommu_debugfs_init(void)
 267 {
 268         iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
 269 }
 270
 271 void __exit omap_iommu_debugfs_exit(void)
 272 {
 273         debugfs_remove(iommu_debug_root);
 274 }