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 
22 #include <plat/iommu.h>
23 #include <plat/iovmm.h>
24 
25 #include <plat/iopgtable.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 omap_iommu *obj = file->private_data;
48 	char *p, *buf;
49 	ssize_t bytes;
50 
51 	buf = kmalloc(count, GFP_KERNEL);
52 	if (!buf)
53 		return -ENOMEM;
54 	p = buf;
55 
56 	mutex_lock(&iommu_debug_lock);
57 
58 	bytes = omap_iommu_dump_ctx(obj, p, count);
59 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
60 
61 	mutex_unlock(&iommu_debug_lock);
62 	kfree(buf);
63 
64 	return bytes;
65 }
66 
67 static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
68 			      size_t count, loff_t *ppos)
69 {
70 	struct omap_iommu *obj = file->private_data;
71 	char *p, *buf;
72 	ssize_t bytes, rest;
73 
74 	buf = kmalloc(count, GFP_KERNEL);
75 	if (!buf)
76 		return -ENOMEM;
77 	p = buf;
78 
79 	mutex_lock(&iommu_debug_lock);
80 
81 	p += sprintf(p, "%8s %8s\n", "cam:", "ram:");
82 	p += sprintf(p, "-----------------------------------------\n");
83 	rest = count - (p - buf);
84 	p += omap_dump_tlb_entries(obj, p, rest);
85 
86 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
87 
88 	mutex_unlock(&iommu_debug_lock);
89 	kfree(buf);
90 
91 	return bytes;
92 }
93 
94 static ssize_t debug_write_pagetable(struct file *file,
95 		     const char __user *userbuf, size_t count, loff_t *ppos)
96 {
97 	struct iotlb_entry e;
98 	struct cr_regs cr;
99 	int err;
100 	struct omap_iommu *obj = file->private_data;
101 	char buf[MAXCOLUMN], *p = buf;
102 
103 	count = min(count, sizeof(buf));
104 
105 	mutex_lock(&iommu_debug_lock);
106 	if (copy_from_user(p, userbuf, count)) {
107 		mutex_unlock(&iommu_debug_lock);
108 		return -EFAULT;
109 	}
110 
111 	sscanf(p, "%x %x", &cr.cam, &cr.ram);
112 	if (!cr.cam || !cr.ram) {
113 		mutex_unlock(&iommu_debug_lock);
114 		return -EINVAL;
115 	}
116 
117 	omap_iotlb_cr_to_e(&cr, &e);
118 	err = omap_iopgtable_store_entry(obj, &e);
119 	if (err)
120 		dev_err(obj->dev, "%s: fail to store cr\n", __func__);
121 
122 	mutex_unlock(&iommu_debug_lock);
123 	return count;
124 }
125 
126 #define dump_ioptable_entry_one(lv, da, val)			\
127 	({							\
128 		int __err = 0;					\
129 		ssize_t bytes;					\
130 		const int maxcol = 22;				\
131 		const char *str = "%d: %08x %08x\n";		\
132 		bytes = snprintf(p, maxcol, str, lv, da, val);	\
133 		p += bytes;					\
134 		len -= bytes;					\
135 		if (len < maxcol)				\
136 			__err = -ENOMEM;			\
137 		__err;						\
138 	})
139 
140 static ssize_t dump_ioptable(struct omap_iommu *obj, char *buf, ssize_t len)
141 {
142 	int i;
143 	u32 *iopgd;
144 	char *p = buf;
145 
146 	spin_lock(&obj->page_table_lock);
147 
148 	iopgd = iopgd_offset(obj, 0);
149 	for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
150 		int j, err;
151 		u32 *iopte;
152 		u32 da;
153 
154 		if (!*iopgd)
155 			continue;
156 
157 		if (!(*iopgd & IOPGD_TABLE)) {
158 			da = i << IOPGD_SHIFT;
159 
160 			err = dump_ioptable_entry_one(1, da, *iopgd);
161 			if (err)
162 				goto out;
163 			continue;
164 		}
165 
166 		iopte = iopte_offset(iopgd, 0);
167 
168 		for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
169 			if (!*iopte)
170 				continue;
171 
172 			da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
173 			err = dump_ioptable_entry_one(2, da, *iopgd);
174 			if (err)
175 				goto out;
176 		}
177 	}
178 out:
179 	spin_unlock(&obj->page_table_lock);
180 
181 	return p - buf;
182 }
183 
184 static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
185 				    size_t count, loff_t *ppos)
186 {
187 	struct omap_iommu *obj = file->private_data;
188 	char *p, *buf;
189 	size_t bytes;
190 
191 	buf = (char *)__get_free_page(GFP_KERNEL);
192 	if (!buf)
193 		return -ENOMEM;
194 	p = buf;
195 
196 	p += sprintf(p, "L: %8s %8s\n", "da:", "pa:");
197 	p += sprintf(p, "-----------------------------------------\n");
198 
199 	mutex_lock(&iommu_debug_lock);
200 
201 	bytes = PAGE_SIZE - (p - buf);
202 	p += dump_ioptable(obj, p, bytes);
203 
204 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
205 
206 	mutex_unlock(&iommu_debug_lock);
207 	free_page((unsigned long)buf);
208 
209 	return bytes;
210 }
211 
212 static ssize_t debug_read_mmap(struct file *file, char __user *userbuf,
213 			       size_t count, loff_t *ppos)
214 {
215 	struct omap_iommu *obj = file->private_data;
216 	char *p, *buf;
217 	struct iovm_struct *tmp;
218 	int uninitialized_var(i);
219 	ssize_t bytes;
220 
221 	buf = (char *)__get_free_page(GFP_KERNEL);
222 	if (!buf)
223 		return -ENOMEM;
224 	p = buf;
225 
226 	p += sprintf(p, "%-3s %-8s %-8s %6s %8s\n",
227 		     "No", "start", "end", "size", "flags");
228 	p += sprintf(p, "-------------------------------------------------\n");
229 
230 	mutex_lock(&iommu_debug_lock);
231 
232 	list_for_each_entry(tmp, &obj->mmap, list) {
233 		size_t len;
234 		const char *str = "%3d %08x-%08x %6x %8x\n";
235 		const int maxcol = 39;
236 
237 		len = tmp->da_end - tmp->da_start;
238 		p += snprintf(p, maxcol, str,
239 			      i, tmp->da_start, tmp->da_end, len, tmp->flags);
240 
241 		if (PAGE_SIZE - (p - buf) < maxcol)
242 			break;
243 		i++;
244 	}
245 
246 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
247 
248 	mutex_unlock(&iommu_debug_lock);
249 	free_page((unsigned long)buf);
250 
251 	return bytes;
252 }
253 
254 static ssize_t debug_read_mem(struct file *file, char __user *userbuf,
255 			      size_t count, loff_t *ppos)
256 {
257 	struct omap_iommu *obj = file->private_data;
258 	char *p, *buf;
259 	struct iovm_struct *area;
260 	ssize_t bytes;
261 
262 	count = min_t(ssize_t, count, PAGE_SIZE);
263 
264 	buf = (char *)__get_free_page(GFP_KERNEL);
265 	if (!buf)
266 		return -ENOMEM;
267 	p = buf;
268 
269 	mutex_lock(&iommu_debug_lock);
270 
271 	area = omap_find_iovm_area(obj, (u32)ppos);
272 	if (IS_ERR(area)) {
273 		bytes = -EINVAL;
274 		goto err_out;
275 	}
276 	memcpy(p, area->va, count);
277 	p += count;
278 
279 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
280 err_out:
281 	mutex_unlock(&iommu_debug_lock);
282 	free_page((unsigned long)buf);
283 
284 	return bytes;
285 }
286 
287 static ssize_t debug_write_mem(struct file *file, const char __user *userbuf,
288 			       size_t count, loff_t *ppos)
289 {
290 	struct omap_iommu *obj = file->private_data;
291 	struct iovm_struct *area;
292 	char *p, *buf;
293 
294 	count = min_t(size_t, count, PAGE_SIZE);
295 
296 	buf = (char *)__get_free_page(GFP_KERNEL);
297 	if (!buf)
298 		return -ENOMEM;
299 	p = buf;
300 
301 	mutex_lock(&iommu_debug_lock);
302 
303 	if (copy_from_user(p, userbuf, count)) {
304 		count =  -EFAULT;
305 		goto err_out;
306 	}
307 
308 	area = omap_find_iovm_area(obj, (u32)ppos);
309 	if (IS_ERR(area)) {
310 		count = -EINVAL;
311 		goto err_out;
312 	}
313 	memcpy(area->va, p, count);
314 err_out:
315 	mutex_unlock(&iommu_debug_lock);
316 	free_page((unsigned long)buf);
317 
318 	return count;
319 }
320 
321 static int debug_open_generic(struct inode *inode, struct file *file)
322 {
323 	file->private_data = inode->i_private;
324 	return 0;
325 }
326 
327 #define DEBUG_FOPS(name)						\
328 	static const struct file_operations debug_##name##_fops = {	\
329 		.open = debug_open_generic,				\
330 		.read = debug_read_##name,				\
331 		.write = debug_write_##name,				\
332 		.llseek = generic_file_llseek,				\
333 	};
334 
335 #define DEBUG_FOPS_RO(name)						\
336 	static const struct file_operations debug_##name##_fops = {	\
337 		.open = debug_open_generic,				\
338 		.read = debug_read_##name,				\
339 		.llseek = generic_file_llseek,				\
340 	};
341 
342 DEBUG_FOPS_RO(ver);
343 DEBUG_FOPS_RO(regs);
344 DEBUG_FOPS_RO(tlb);
345 DEBUG_FOPS(pagetable);
346 DEBUG_FOPS_RO(mmap);
347 DEBUG_FOPS(mem);
348 
349 #define __DEBUG_ADD_FILE(attr, mode)					\
350 	{								\
351 		struct dentry *dent;					\
352 		dent = debugfs_create_file(#attr, mode, parent,		\
353 					   obj, &debug_##attr##_fops);	\
354 		if (!dent)						\
355 			return -ENOMEM;					\
356 	}
357 
358 #define DEBUG_ADD_FILE(name) __DEBUG_ADD_FILE(name, 600)
359 #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 400)
360 
361 static int iommu_debug_register(struct device *dev, void *data)
362 {
363 	struct platform_device *pdev = to_platform_device(dev);
364 	struct omap_iommu *obj = platform_get_drvdata(pdev);
365 	struct dentry *d, *parent;
366 
367 	if (!obj || !obj->dev)
368 		return -EINVAL;
369 
370 	d = debugfs_create_dir(obj->name, iommu_debug_root);
371 	if (!d)
372 		return -ENOMEM;
373 	parent = d;
374 
375 	d = debugfs_create_u8("nr_tlb_entries", 400, parent,
376 			      (u8 *)&obj->nr_tlb_entries);
377 	if (!d)
378 		return -ENOMEM;
379 
380 	DEBUG_ADD_FILE_RO(ver);
381 	DEBUG_ADD_FILE_RO(regs);
382 	DEBUG_ADD_FILE_RO(tlb);
383 	DEBUG_ADD_FILE(pagetable);
384 	DEBUG_ADD_FILE_RO(mmap);
385 	DEBUG_ADD_FILE(mem);
386 
387 	return 0;
388 }
389 
390 static int __init iommu_debug_init(void)
391 {
392 	struct dentry *d;
393 	int err;
394 
395 	d = debugfs_create_dir("iommu", NULL);
396 	if (!d)
397 		return -ENOMEM;
398 	iommu_debug_root = d;
399 
400 	err = omap_foreach_iommu_device(d, iommu_debug_register);
401 	if (err)
402 		goto err_out;
403 	return 0;
404 
405 err_out:
406 	debugfs_remove_recursive(iommu_debug_root);
407 	return err;
408 }
409 module_init(iommu_debug_init)
410 
411 static void __exit iommu_debugfs_exit(void)
412 {
413 	debugfs_remove_recursive(iommu_debug_root);
414 }
415 module_exit(iommu_debugfs_exit)
416 
417 MODULE_DESCRIPTION("omap iommu: debugfs interface");
418 MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
419 MODULE_LICENSE("GPL v2");
420