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
23static DEFINE_MUTEX(iommu_debug_lock);
24
25static struct dentry *iommu_debug_root;
26
27static inline bool is_omap_iommu_detached(struct omap_iommu *obj)
28{
29	return !obj->domain;
30}
31
32static 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
58static 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
88static 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
121static 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
159DEBUG_FOPS_RO(regs);
160DEBUG_FOPS_RO(tlb);
161DEBUG_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
174void 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
196err:
197	debugfs_remove_recursive(obj->debug_dir);
198}
199
200void 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
208void __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
215void __exit omap_iommu_debugfs_exit(void)
216{
217	debugfs_remove(iommu_debug_root);
218}
219