drivers/iommu/omap-iommu-debug.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * omap iommu: debugfs interface
0004  *
0005  * Copyright (C) 2008-2009 Nokia Corporation
0006  *
0007  * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
0008  */
0009
0010 #include <linux/err.h>
0011 #include <linux/io.h>
0012 #include <linux/slab.h>
0013 #include <linux/uaccess.h>
0014 #include <linux/pm_runtime.h>
0015 #include <linux/debugfs.h>
0016 #include <linux/platform_data/iommu-omap.h>
0017
0018 #include "omap-iopgtable.h"
0019 #include "omap-iommu.h"
0020
0021 static DEFINE_MUTEX(iommu_debug_lock);
0022
0023 static struct dentry *iommu_debug_root;
0024
0025 static inline bool is_omap_iommu_detached(struct omap_iommu *obj)
0026 {
0027     return !obj->domain;
0028 }
0029
0030 #define pr_reg(name)                            \
0031     do {                                \
0032         ssize_t bytes;                      \
0033         const char *str = "%20s: %08x\n";           \
0034         const int maxcol = 32;                  \
0035         bytes = snprintf(p, maxcol, str, __stringify(name), \
0036                  iommu_read_reg(obj, MMU_##name));  \
0037         p += bytes;                     \
0038         len -= bytes;                       \
0039         if (len < maxcol)                   \
0040             goto out;                   \
0041     } while (0)
0042
0043 static ssize_t
0044 omap2_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len)
0045 {
0046     char *p = buf;
0047
0048     pr_reg(REVISION);
0049     pr_reg(IRQSTATUS);
0050     pr_reg(IRQENABLE);
0051     pr_reg(WALKING_ST);
0052     pr_reg(CNTL);
0053     pr_reg(FAULT_AD);
0054     pr_reg(TTB);
0055     pr_reg(LOCK);
0056     pr_reg(LD_TLB);
0057     pr_reg(CAM);
0058     pr_reg(RAM);
0059     pr_reg(GFLUSH);
0060     pr_reg(FLUSH_ENTRY);
0061     pr_reg(READ_CAM);
0062     pr_reg(READ_RAM);
0063     pr_reg(EMU_FAULT_AD);
0064 out:
0065     return p - buf;
0066 }
0067
0068 static ssize_t omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf,
0069                    ssize_t bytes)
0070 {
0071     if (!obj || !buf)
0072         return -EINVAL;
0073
0074     pm_runtime_get_sync(obj->dev);
0075
0076     bytes = omap2_iommu_dump_ctx(obj, buf, bytes);
0077
0078     pm_runtime_put_sync(obj->dev);
0079
0080     return bytes;
0081 }
0082
0083 static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
0084                    size_t count, loff_t *ppos)
0085 {
0086     struct omap_iommu *obj = file->private_data;
0087     char *p, *buf;
0088     ssize_t bytes;
0089
0090     if (is_omap_iommu_detached(obj))
0091         return -EPERM;
0092
0093     buf = kmalloc(count, GFP_KERNEL);
0094     if (!buf)
0095         return -ENOMEM;
0096     p = buf;
0097
0098     mutex_lock(&iommu_debug_lock);
0099
0100     bytes = omap_iommu_dump_ctx(obj, p, count);
0101     if (bytes < 0)
0102         goto err;
0103     bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
0104
0105 err:
0106     mutex_unlock(&iommu_debug_lock);
0107     kfree(buf);
0108
0109     return bytes;
0110 }
0111
0112 static int
0113 __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
0114 {
0115     int i;
0116     struct iotlb_lock saved;
0117     struct cr_regs tmp;
0118     struct cr_regs *p = crs;
0119
0120     pm_runtime_get_sync(obj->dev);
0121     iotlb_lock_get(obj, &saved);
0122
0123     for_each_iotlb_cr(obj, num, i, tmp) {
0124         if (!iotlb_cr_valid(&tmp))
0125             continue;
0126         *p++ = tmp;
0127     }
0128
0129     iotlb_lock_set(obj, &saved);
0130     pm_runtime_put_sync(obj->dev);
0131
0132     return  p - crs;
0133 }
0134
0135 static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
0136                  struct seq_file *s)
0137 {
0138     seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
0139            (cr->cam & MMU_CAM_P) ? 1 : 0);
0140     return 0;
0141 }
0142
0143 static size_t omap_dump_tlb_entries(struct omap_iommu *obj, struct seq_file *s)
0144 {
0145     int i, num;
0146     struct cr_regs *cr;
0147
0148     num = obj->nr_tlb_entries;
0149
0150     cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
0151     if (!cr)
0152         return 0;
0153
0154     num = __dump_tlb_entries(obj, cr, num);
0155     for (i = 0; i < num; i++)
0156         iotlb_dump_cr(obj, cr + i, s);
0157     kfree(cr);
0158
0159     return 0;
0160 }
0161
0162 static int tlb_show(struct seq_file *s, void *data)
0163 {
0164     struct omap_iommu *obj = s->private;
0165
0166     if (is_omap_iommu_detached(obj))
0167         return -EPERM;
0168
0169     mutex_lock(&iommu_debug_lock);
0170
0171     seq_printf(s, "%8s %8s\n", "cam:", "ram:");
0172     seq_puts(s, "-----------------------------------------\n");
0173     omap_dump_tlb_entries(obj, s);
0174
0175     mutex_unlock(&iommu_debug_lock);
0176
0177     return 0;
0178 }
0179
0180 static void dump_ioptable(struct seq_file *s)
0181 {
0182     int i, j;
0183     u32 da;
0184     u32 *iopgd, *iopte;
0185     struct omap_iommu *obj = s->private;
0186
0187     spin_lock(&obj->page_table_lock);
0188
0189     iopgd = iopgd_offset(obj, 0);
0190     for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
0191         if (!*iopgd)
0192             continue;
0193
0194         if (!(*iopgd & IOPGD_TABLE)) {
0195             da = i << IOPGD_SHIFT;
0196             seq_printf(s, "1: 0x%08x 0x%08x\n", da, *iopgd);
0197             continue;
0198         }
0199
0200         iopte = iopte_offset(iopgd, 0);
0201         for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
0202             if (!*iopte)
0203                 continue;
0204
0205             da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
0206             seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
0207         }
0208     }
0209
0210     spin_unlock(&obj->page_table_lock);
0211 }
0212
0213 static int pagetable_show(struct seq_file *s, void *data)
0214 {
0215     struct omap_iommu *obj = s->private;
0216
0217     if (is_omap_iommu_detached(obj))
0218         return -EPERM;
0219
0220     mutex_lock(&iommu_debug_lock);
0221
0222     seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
0223     seq_puts(s, "--------------------------\n");
0224     dump_ioptable(s);
0225
0226     mutex_unlock(&iommu_debug_lock);
0227
0228     return 0;
0229 }
0230
0231 #define DEBUG_FOPS_RO(name)                     \
0232     static const struct file_operations name##_fops = {         \
0233         .open = simple_open,                    \
0234         .read = debug_read_##name,              \
0235         .llseek = generic_file_llseek,              \
0236     }
0237
0238 DEBUG_FOPS_RO(regs);
0239 DEFINE_SHOW_ATTRIBUTE(tlb);
0240 DEFINE_SHOW_ATTRIBUTE(pagetable);
0241
0242 void omap_iommu_debugfs_add(struct omap_iommu *obj)
0243 {
0244     struct dentry *d;
0245
0246     if (!iommu_debug_root)
0247         return;
0248
0249     d = debugfs_create_dir(obj->name, iommu_debug_root);
0250     obj->debug_dir = d;
0251
0252     debugfs_create_u32("nr_tlb_entries", 0400, d, &obj->nr_tlb_entries);
0253     debugfs_create_file("regs", 0400, d, obj, &regs_fops);
0254     debugfs_create_file("tlb", 0400, d, obj, &tlb_fops);
0255     debugfs_create_file("pagetable", 0400, d, obj, &pagetable_fops);
0256 }
0257
0258 void omap_iommu_debugfs_remove(struct omap_iommu *obj)
0259 {
0260     if (!obj->debug_dir)
0261         return;
0262
0263     debugfs_remove_recursive(obj->debug_dir);
0264 }
0265
0266 void __init omap_iommu_debugfs_init(void)
0267 {
0268     iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
0269 }
0270
0271 void __exit omap_iommu_debugfs_exit(void)
0272 {
0273     debugfs_remove(iommu_debug_root);
0274 }