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/module.h>
14 #include <linux/err.h>
15 #include <linux/clk.h>
16 #include <linux/io.h>
17 #include <linux/slab.h>
18 #include <linux/uaccess.h>
19 #include <linux/platform_device.h>
20 #include <linux/debugfs.h>
21 #include <linux/omap-iommu.h>
22 #include <linux/platform_data/iommu-omap.h>
23 
24 #include "omap-iopgtable.h"
25 #include "omap-iommu.h"
26 
27 #define MAXCOLUMN 100 /* for short messages */
28 
29 static DEFINE_MUTEX(iommu_debug_lock);
30 
31 static struct dentry *iommu_debug_root;
32 
33 static ssize_t debug_read_ver(struct file *file, char __user *userbuf,
34 			      size_t count, loff_t *ppos)
35 {
36 	u32 ver = omap_iommu_arch_version();
37 	char buf[MAXCOLUMN], *p = buf;
38 
39 	p += sprintf(p, "H/W version: %d.%d\n", (ver >> 4) & 0xf , ver & 0xf);
40 
41 	return simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
42 }
43 
44 static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
45 			       size_t count, loff_t *ppos)
46 {
47 	struct device *dev = file->private_data;
48 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
49 	char *p, *buf;
50 	ssize_t bytes;
51 
52 	buf = kmalloc(count, GFP_KERNEL);
53 	if (!buf)
54 		return -ENOMEM;
55 	p = buf;
56 
57 	mutex_lock(&iommu_debug_lock);
58 
59 	bytes = omap_iommu_dump_ctx(obj, p, count);
60 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
61 
62 	mutex_unlock(&iommu_debug_lock);
63 	kfree(buf);
64 
65 	return bytes;
66 }
67 
68 static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
69 			      size_t count, loff_t *ppos)
70 {
71 	struct device *dev = file->private_data;
72 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
73 	char *p, *buf;
74 	ssize_t bytes, rest;
75 
76 	buf = kmalloc(count, GFP_KERNEL);
77 	if (!buf)
78 		return -ENOMEM;
79 	p = buf;
80 
81 	mutex_lock(&iommu_debug_lock);
82 
83 	p += sprintf(p, "%8s %8s\n", "cam:", "ram:");
84 	p += sprintf(p, "-----------------------------------------\n");
85 	rest = count - (p - buf);
86 	p += omap_dump_tlb_entries(obj, p, rest);
87 
88 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
89 
90 	mutex_unlock(&iommu_debug_lock);
91 	kfree(buf);
92 
93 	return bytes;
94 }
95 
96 static ssize_t debug_write_pagetable(struct file *file,
97 		     const char __user *userbuf, size_t count, loff_t *ppos)
98 {
99 	struct iotlb_entry e;
100 	struct cr_regs cr;
101 	int err;
102 	struct device *dev = file->private_data;
103 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
104 	char buf[MAXCOLUMN], *p = buf;
105 
106 	count = min(count, sizeof(buf));
107 
108 	mutex_lock(&iommu_debug_lock);
109 	if (copy_from_user(p, userbuf, count)) {
110 		mutex_unlock(&iommu_debug_lock);
111 		return -EFAULT;
112 	}
113 
114 	sscanf(p, "%x %x", &cr.cam, &cr.ram);
115 	if (!cr.cam || !cr.ram) {
116 		mutex_unlock(&iommu_debug_lock);
117 		return -EINVAL;
118 	}
119 
120 	omap_iotlb_cr_to_e(&cr, &e);
121 	err = omap_iopgtable_store_entry(obj, &e);
122 	if (err)
123 		dev_err(obj->dev, "%s: fail to store cr\n", __func__);
124 
125 	mutex_unlock(&iommu_debug_lock);
126 	return count;
127 }
128 
129 #define dump_ioptable_entry_one(lv, da, val)			\
130 	({							\
131 		int __err = 0;					\
132 		ssize_t bytes;					\
133 		const int maxcol = 22;				\
134 		const char *str = "%d: %08x %08x\n";		\
135 		bytes = snprintf(p, maxcol, str, lv, da, val);	\
136 		p += bytes;					\
137 		len -= bytes;					\
138 		if (len < maxcol)				\
139 			__err = -ENOMEM;			\
140 		__err;						\
141 	})
142 
143 static ssize_t dump_ioptable(struct omap_iommu *obj, char *buf, ssize_t len)
144 {
145 	int i;
146 	u32 *iopgd;
147 	char *p = buf;
148 
149 	spin_lock(&obj->page_table_lock);
150 
151 	iopgd = iopgd_offset(obj, 0);
152 	for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
153 		int j, err;
154 		u32 *iopte;
155 		u32 da;
156 
157 		if (!*iopgd)
158 			continue;
159 
160 		if (!(*iopgd & IOPGD_TABLE)) {
161 			da = i << IOPGD_SHIFT;
162 
163 			err = dump_ioptable_entry_one(1, da, *iopgd);
164 			if (err)
165 				goto out;
166 			continue;
167 		}
168 
169 		iopte = iopte_offset(iopgd, 0);
170 
171 		for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
172 			if (!*iopte)
173 				continue;
174 
175 			da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
176 			err = dump_ioptable_entry_one(2, da, *iopgd);
177 			if (err)
178 				goto out;
179 		}
180 	}
181 out:
182 	spin_unlock(&obj->page_table_lock);
183 
184 	return p - buf;
185 }
186 
187 static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
188 				    size_t count, loff_t *ppos)
189 {
190 	struct device *dev = file->private_data;
191 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
192 	char *p, *buf;
193 	size_t bytes;
194 
195 	buf = (char *)__get_free_page(GFP_KERNEL);
196 	if (!buf)
197 		return -ENOMEM;
198 	p = buf;
199 
200 	p += sprintf(p, "L: %8s %8s\n", "da:", "pa:");
201 	p += sprintf(p, "-----------------------------------------\n");
202 
203 	mutex_lock(&iommu_debug_lock);
204 
205 	bytes = PAGE_SIZE - (p - buf);
206 	p += dump_ioptable(obj, p, bytes);
207 
208 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
209 
210 	mutex_unlock(&iommu_debug_lock);
211 	free_page((unsigned long)buf);
212 
213 	return bytes;
214 }
215 
216 #define DEBUG_FOPS(name)						\
217 	static const struct file_operations debug_##name##_fops = {	\
218 		.open = simple_open,					\
219 		.read = debug_read_##name,				\
220 		.write = debug_write_##name,				\
221 		.llseek = generic_file_llseek,				\
222 	};
223 
224 #define DEBUG_FOPS_RO(name)						\
225 	static const struct file_operations debug_##name##_fops = {	\
226 		.open = simple_open,					\
227 		.read = debug_read_##name,				\
228 		.llseek = generic_file_llseek,				\
229 	};
230 
231 DEBUG_FOPS_RO(ver);
232 DEBUG_FOPS_RO(regs);
233 DEBUG_FOPS_RO(tlb);
234 DEBUG_FOPS(pagetable);
235 
236 #define __DEBUG_ADD_FILE(attr, mode)					\
237 	{								\
238 		struct dentry *dent;					\
239 		dent = debugfs_create_file(#attr, mode, parent,		\
240 					   dev, &debug_##attr##_fops);	\
241 		if (!dent)						\
242 			return -ENOMEM;					\
243 	}
244 
245 #define DEBUG_ADD_FILE(name) __DEBUG_ADD_FILE(name, 0600)
246 #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
247 
248 static int iommu_debug_register(struct device *dev, void *data)
249 {
250 	struct platform_device *pdev = to_platform_device(dev);
251 	struct omap_iommu *obj = platform_get_drvdata(pdev);
252 	struct omap_iommu_arch_data *arch_data;
253 	struct dentry *d, *parent;
254 
255 	if (!obj || !obj->dev)
256 		return -EINVAL;
257 
258 	arch_data = kzalloc(sizeof(*arch_data), GFP_KERNEL);
259 	if (!arch_data)
260 		return -ENOMEM;
261 
262 	arch_data->iommu_dev = obj;
263 
264 	dev->archdata.iommu = arch_data;
265 
266 	d = debugfs_create_dir(obj->name, iommu_debug_root);
267 	if (!d)
268 		goto nomem;
269 	parent = d;
270 
271 	d = debugfs_create_u8("nr_tlb_entries", 400, parent,
272 			      (u8 *)&obj->nr_tlb_entries);
273 	if (!d)
274 		goto nomem;
275 
276 	DEBUG_ADD_FILE_RO(ver);
277 	DEBUG_ADD_FILE_RO(regs);
278 	DEBUG_ADD_FILE_RO(tlb);
279 	DEBUG_ADD_FILE(pagetable);
280 
281 	return 0;
282 
283 nomem:
284 	kfree(arch_data);
285 	return -ENOMEM;
286 }
287 
288 static int iommu_debug_unregister(struct device *dev, void *data)
289 {
290 	if (!dev->archdata.iommu)
291 		return 0;
292 
293 	kfree(dev->archdata.iommu);
294 
295 	dev->archdata.iommu = NULL;
296 
297 	return 0;
298 }
299 
300 static int __init iommu_debug_init(void)
301 {
302 	struct dentry *d;
303 	int err;
304 
305 	d = debugfs_create_dir("iommu", NULL);
306 	if (!d)
307 		return -ENOMEM;
308 	iommu_debug_root = d;
309 
310 	err = omap_foreach_iommu_device(d, iommu_debug_register);
311 	if (err)
312 		goto err_out;
313 	return 0;
314 
315 err_out:
316 	debugfs_remove_recursive(iommu_debug_root);
317 	return err;
318 }
319 module_init(iommu_debug_init)
320 
321 static void __exit iommu_debugfs_exit(void)
322 {
323 	debugfs_remove_recursive(iommu_debug_root);
324 	omap_foreach_iommu_device(NULL, iommu_debug_unregister);
325 }
326 module_exit(iommu_debugfs_exit)
327 
328 MODULE_DESCRIPTION("omap iommu: debugfs interface");
329 MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
330 MODULE_LICENSE("GPL v2");
331