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/pm_runtime.h>
18#include <linux/debugfs.h>
19#include <linux/platform_data/iommu-omap.h>
20
21#include "omap-iopgtable.h"
22#include "omap-iommu.h"
23
24static DEFINE_MUTEX(iommu_debug_lock);
25
26static struct dentry *iommu_debug_root;
27
28static inline bool is_omap_iommu_detached(struct omap_iommu *obj)
29{
30	return !obj->domain;
31}
32
33#define pr_reg(name)							\
34	do {								\
35		ssize_t bytes;						\
36		const char *str = "%20s: %08x\n";			\
37		const int maxcol = 32;					\
38		bytes = snprintf(p, maxcol, str, __stringify(name),	\
39				 iommu_read_reg(obj, MMU_##name));	\
40		p += bytes;						\
41		len -= bytes;						\
42		if (len < maxcol)					\
43			goto out;					\
44	} while (0)
45
46static ssize_t
47omap2_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len)
48{
49	char *p = buf;
50
51	pr_reg(REVISION);
52	pr_reg(IRQSTATUS);
53	pr_reg(IRQENABLE);
54	pr_reg(WALKING_ST);
55	pr_reg(CNTL);
56	pr_reg(FAULT_AD);
57	pr_reg(TTB);
58	pr_reg(LOCK);
59	pr_reg(LD_TLB);
60	pr_reg(CAM);
61	pr_reg(RAM);
62	pr_reg(GFLUSH);
63	pr_reg(FLUSH_ENTRY);
64	pr_reg(READ_CAM);
65	pr_reg(READ_RAM);
66	pr_reg(EMU_FAULT_AD);
67out:
68	return p - buf;
69}
70
71static ssize_t omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf,
72				   ssize_t bytes)
73{
74	if (!obj || !buf)
75		return -EINVAL;
76
77	pm_runtime_get_sync(obj->dev);
78
79	bytes = omap2_iommu_dump_ctx(obj, buf, bytes);
80
81	pm_runtime_put_sync(obj->dev);
82
83	return bytes;
84}
85
86static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
87			       size_t count, loff_t *ppos)
88{
89	struct omap_iommu *obj = file->private_data;
90	char *p, *buf;
91	ssize_t bytes;
92
93	if (is_omap_iommu_detached(obj))
94		return -EPERM;
95
96	buf = kmalloc(count, GFP_KERNEL);
97	if (!buf)
98		return -ENOMEM;
99	p = buf;
100
101	mutex_lock(&iommu_debug_lock);
102
103	bytes = omap_iommu_dump_ctx(obj, p, count);
104	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
105
106	mutex_unlock(&iommu_debug_lock);
107	kfree(buf);
108
109	return bytes;
110}
111
112static int
113__dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
114{
115	int i;
116	struct iotlb_lock saved;
117	struct cr_regs tmp;
118	struct cr_regs *p = crs;
119
120	pm_runtime_get_sync(obj->dev);
121	iotlb_lock_get(obj, &saved);
122
123	for_each_iotlb_cr(obj, num, i, tmp) {
124		if (!iotlb_cr_valid(&tmp))
125			continue;
126		*p++ = tmp;
127	}
128
129	iotlb_lock_set(obj, &saved);
130	pm_runtime_put_sync(obj->dev);
131
132	return  p - crs;
133}
134
135static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
136			     struct seq_file *s)
137{
138	seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
139			  (cr->cam & MMU_CAM_P) ? 1 : 0);
140	return 0;
141}
142
143static size_t omap_dump_tlb_entries(struct omap_iommu *obj, struct seq_file *s)
144{
145	int i, num;
146	struct cr_regs *cr;
147
148	num = obj->nr_tlb_entries;
149
150	cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
151	if (!cr)
152		return 0;
153
154	num = __dump_tlb_entries(obj, cr, num);
155	for (i = 0; i < num; i++)
156		iotlb_dump_cr(obj, cr + i, s);
157	kfree(cr);
158
159	return 0;
160}
161
162static int debug_read_tlb(struct seq_file *s, void *data)
163{
164	struct omap_iommu *obj = s->private;
165
166	if (is_omap_iommu_detached(obj))
167		return -EPERM;
168
169	mutex_lock(&iommu_debug_lock);
170
171	seq_printf(s, "%8s %8s\n", "cam:", "ram:");
172	seq_puts(s, "-----------------------------------------\n");
173	omap_dump_tlb_entries(obj, s);
174
175	mutex_unlock(&iommu_debug_lock);
176
177	return 0;
178}
179
180static void dump_ioptable(struct seq_file *s)
181{
182	int i, j;
183	u32 da;
184	u32 *iopgd, *iopte;
185	struct omap_iommu *obj = s->private;
186
187	spin_lock(&obj->page_table_lock);
188
189	iopgd = iopgd_offset(obj, 0);
190	for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
191		if (!*iopgd)
192			continue;
193
194		if (!(*iopgd & IOPGD_TABLE)) {
195			da = i << IOPGD_SHIFT;
196			seq_printf(s, "1: 0x%08x 0x%08x\n", da, *iopgd);
197			continue;
198		}
199
200		iopte = iopte_offset(iopgd, 0);
201		for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
202			if (!*iopte)
203				continue;
204
205			da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
206			seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
207		}
208	}
209
210	spin_unlock(&obj->page_table_lock);
211}
212
213static int debug_read_pagetable(struct seq_file *s, void *data)
214{
215	struct omap_iommu *obj = s->private;
216
217	if (is_omap_iommu_detached(obj))
218		return -EPERM;
219
220	mutex_lock(&iommu_debug_lock);
221
222	seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
223	seq_puts(s, "--------------------------\n");
224	dump_ioptable(s);
225
226	mutex_unlock(&iommu_debug_lock);
227
228	return 0;
229}
230
231#define DEBUG_SEQ_FOPS_RO(name)						       \
232	static int debug_open_##name(struct inode *inode, struct file *file)   \
233	{								       \
234		return single_open(file, debug_read_##name, inode->i_private); \
235	}								       \
236									       \
237	static const struct file_operations debug_##name##_fops = {	       \
238		.open		= debug_open_##name,			       \
239		.read		= seq_read,				       \
240		.llseek		= seq_lseek,				       \
241		.release	= single_release,			       \
242	}
243
244#define DEBUG_FOPS_RO(name)						\
245	static const struct file_operations debug_##name##_fops = {	\
246		.open = simple_open,					\
247		.read = debug_read_##name,				\
248		.llseek = generic_file_llseek,				\
249	}
250
251DEBUG_FOPS_RO(regs);
252DEBUG_SEQ_FOPS_RO(tlb);
253DEBUG_SEQ_FOPS_RO(pagetable);
254
255#define __DEBUG_ADD_FILE(attr, mode)					\
256	{								\
257		struct dentry *dent;					\
258		dent = debugfs_create_file(#attr, mode, obj->debug_dir,	\
259					   obj, &debug_##attr##_fops);	\
260		if (!dent)						\
261			goto err;					\
262	}
263
264#define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
265
266void omap_iommu_debugfs_add(struct omap_iommu *obj)
267{
268	struct dentry *d;
269
270	if (!iommu_debug_root)
271		return;
272
273	obj->debug_dir = debugfs_create_dir(obj->name, iommu_debug_root);
274	if (!obj->debug_dir)
275		return;
276
277	d = debugfs_create_u8("nr_tlb_entries", 0400, obj->debug_dir,
278			      (u8 *)&obj->nr_tlb_entries);
279	if (!d)
280		return;
281
282	DEBUG_ADD_FILE_RO(regs);
283	DEBUG_ADD_FILE_RO(tlb);
284	DEBUG_ADD_FILE_RO(pagetable);
285
286	return;
287
288err:
289	debugfs_remove_recursive(obj->debug_dir);
290}
291
292void omap_iommu_debugfs_remove(struct omap_iommu *obj)
293{
294	if (!obj->debug_dir)
295		return;
296
297	debugfs_remove_recursive(obj->debug_dir);
298}
299
300void __init omap_iommu_debugfs_init(void)
301{
302	iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
303	if (!iommu_debug_root)
304		pr_err("can't create debugfs dir\n");
305}
306
307void __exit omap_iommu_debugfs_exit(void)
308{
309	debugfs_remove(iommu_debug_root);
310}
311