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/debugfs.h>
18 #include <linux/platform_data/iommu-omap.h>
19 
20 #include "omap-iopgtable.h"
21 #include "omap-iommu.h"
22 
23 static DEFINE_MUTEX(iommu_debug_lock);
24 
25 static struct dentry *iommu_debug_root;
26 
27 static inline bool is_omap_iommu_detached(struct omap_iommu *obj)
28 {
29 	return !obj->domain;
30 }
31 
32 static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
33 			       size_t count, loff_t *ppos)
34 {
35 	struct omap_iommu *obj = file->private_data;
36 	char *p, *buf;
37 	ssize_t bytes;
38 
39 	if (is_omap_iommu_detached(obj))
40 		return -EPERM;
41 
42 	buf = kmalloc(count, GFP_KERNEL);
43 	if (!buf)
44 		return -ENOMEM;
45 	p = buf;
46 
47 	mutex_lock(&iommu_debug_lock);
48 
49 	bytes = omap_iommu_dump_ctx(obj, p, count);
50 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
51 
52 	mutex_unlock(&iommu_debug_lock);
53 	kfree(buf);
54 
55 	return bytes;
56 }
57 
58 static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
59 			      size_t count, loff_t *ppos)
60 {
61 	struct omap_iommu *obj = file->private_data;
62 	char *p, *buf;
63 	ssize_t bytes, rest;
64 
65 	if (is_omap_iommu_detached(obj))
66 		return -EPERM;
67 
68 	buf = kmalloc(count, GFP_KERNEL);
69 	if (!buf)
70 		return -ENOMEM;
71 	p = buf;
72 
73 	mutex_lock(&iommu_debug_lock);
74 
75 	p += sprintf(p, "%8s %8s\n", "cam:", "ram:");
76 	p += sprintf(p, "-----------------------------------------\n");
77 	rest = count - (p - buf);
78 	p += omap_dump_tlb_entries(obj, p, rest);
79 
80 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
81 
82 	mutex_unlock(&iommu_debug_lock);
83 	kfree(buf);
84 
85 	return bytes;
86 }
87 
88 static void dump_ioptable(struct seq_file *s)
89 {
90 	int i, j;
91 	u32 da;
92 	u32 *iopgd, *iopte;
93 	struct omap_iommu *obj = s->private;
94 
95 	spin_lock(&obj->page_table_lock);
96 
97 	iopgd = iopgd_offset(obj, 0);
98 	for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
99 		if (!*iopgd)
100 			continue;
101 
102 		if (!(*iopgd & IOPGD_TABLE)) {
103 			da = i << IOPGD_SHIFT;
104 			seq_printf(s, "1: 0x%08x 0x%08x\n", da, *iopgd);
105 			continue;
106 		}
107 
108 		iopte = iopte_offset(iopgd, 0);
109 		for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
110 			if (!*iopte)
111 				continue;
112 
113 			da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
114 			seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
115 		}
116 	}
117 
118 	spin_unlock(&obj->page_table_lock);
119 }
120 
121 static int debug_read_pagetable(struct seq_file *s, void *data)
122 {
123 	struct omap_iommu *obj = s->private;
124 
125 	if (is_omap_iommu_detached(obj))
126 		return -EPERM;
127 
128 	mutex_lock(&iommu_debug_lock);
129 
130 	seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
131 	seq_puts(s, "--------------------------\n");
132 	dump_ioptable(s);
133 
134 	mutex_unlock(&iommu_debug_lock);
135 
136 	return 0;
137 }
138 
139 #define DEBUG_SEQ_FOPS_RO(name)						       \
140 	static int debug_open_##name(struct inode *inode, struct file *file)   \
141 	{								       \
142 		return single_open(file, debug_read_##name, inode->i_private); \
143 	}								       \
144 									       \
145 	static const struct file_operations debug_##name##_fops = {	       \
146 		.open		= debug_open_##name,			       \
147 		.read		= seq_read,				       \
148 		.llseek		= seq_lseek,				       \
149 		.release	= single_release,			       \
150 	}
151 
152 #define DEBUG_FOPS_RO(name)						\
153 	static const struct file_operations debug_##name##_fops = {	\
154 		.open = simple_open,					\
155 		.read = debug_read_##name,				\
156 		.llseek = generic_file_llseek,				\
157 	};
158 
159 DEBUG_FOPS_RO(regs);
160 DEBUG_FOPS_RO(tlb);
161 DEBUG_SEQ_FOPS_RO(pagetable);
162 
163 #define __DEBUG_ADD_FILE(attr, mode)					\
164 	{								\
165 		struct dentry *dent;					\
166 		dent = debugfs_create_file(#attr, mode, obj->debug_dir,	\
167 					   obj, &debug_##attr##_fops);	\
168 		if (!dent)						\
169 			goto err;					\
170 	}
171 
172 #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
173 
174 void omap_iommu_debugfs_add(struct omap_iommu *obj)
175 {
176 	struct dentry *d;
177 
178 	if (!iommu_debug_root)
179 		return;
180 
181 	obj->debug_dir = debugfs_create_dir(obj->name, iommu_debug_root);
182 	if (!obj->debug_dir)
183 		return;
184 
185 	d = debugfs_create_u8("nr_tlb_entries", 0400, obj->debug_dir,
186 			      (u8 *)&obj->nr_tlb_entries);
187 	if (!d)
188 		return;
189 
190 	DEBUG_ADD_FILE_RO(regs);
191 	DEBUG_ADD_FILE_RO(tlb);
192 	DEBUG_ADD_FILE_RO(pagetable);
193 
194 	return;
195 
196 err:
197 	debugfs_remove_recursive(obj->debug_dir);
198 }
199 
200 void omap_iommu_debugfs_remove(struct omap_iommu *obj)
201 {
202 	if (!obj->debug_dir)
203 		return;
204 
205 	debugfs_remove_recursive(obj->debug_dir);
206 }
207 
208 void __init omap_iommu_debugfs_init(void)
209 {
210 	iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
211 	if (!iommu_debug_root)
212 		pr_err("can't create debugfs dir\n");
213 }
214 
215 void __exit omap_iommu_debugfs_exit(void)
216 {
217 	debugfs_remove(iommu_debug_root);
218 }
219