1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * omap iommu: debugfs interface
4 *
5 * Copyright (C) 2008-2009 Nokia Corporation
6 *
7 * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
8 */
9
10#include <linux/err.h>
11#include <linux/io.h>
12#include <linux/slab.h>
13#include <linux/uaccess.h>
14#include <linux/pm_runtime.h>
15#include <linux/debugfs.h>
16#include <linux/platform_data/iommu-omap.h>
17
18#include "omap-iopgtable.h"
19#include "omap-iommu.h"
20
21static DEFINE_MUTEX(iommu_debug_lock);
22
23static struct dentry *iommu_debug_root;
24
25static inline bool is_omap_iommu_detached(struct omap_iommu *obj)
26{
27	return !obj->domain;
28}
29
30#define pr_reg(name)							\
31	do {								\
32		ssize_t bytes;						\
33		const char *str = "%20s: %08x\n";			\
34		const int maxcol = 32;					\
35		if (len < maxcol)					\
36			goto out;					\
37		bytes = scnprintf(p, maxcol, str, __stringify(name),	\
38				 iommu_read_reg(obj, MMU_##name));	\
39		p += bytes;						\
40		len -= bytes;						\
41	} while (0)
42
43static ssize_t
44omap2_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len)
45{
46	char *p = buf;
47
48	pr_reg(REVISION);
49	pr_reg(IRQSTATUS);
50	pr_reg(IRQENABLE);
51	pr_reg(WALKING_ST);
52	pr_reg(CNTL);
53	pr_reg(FAULT_AD);
54	pr_reg(TTB);
55	pr_reg(LOCK);
56	pr_reg(LD_TLB);
57	pr_reg(CAM);
58	pr_reg(RAM);
59	pr_reg(GFLUSH);
60	pr_reg(FLUSH_ENTRY);
61	pr_reg(READ_CAM);
62	pr_reg(READ_RAM);
63	pr_reg(EMU_FAULT_AD);
64out:
65	return p - buf;
66}
67
68static ssize_t omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf,
69				   ssize_t bytes)
70{
71	if (!obj || !buf)
72		return -EINVAL;
73
74	pm_runtime_get_sync(obj->dev);
75
76	bytes = omap2_iommu_dump_ctx(obj, buf, bytes);
77
78	pm_runtime_put_sync(obj->dev);
79
80	return bytes;
81}
82
83static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
84			       size_t count, loff_t *ppos)
85{
86	struct omap_iommu *obj = file->private_data;
87	char *p, *buf;
88	ssize_t bytes;
89
90	if (is_omap_iommu_detached(obj))
91		return -EPERM;
92
93	buf = kmalloc(count, GFP_KERNEL);
94	if (!buf)
95		return -ENOMEM;
96	p = buf;
97
98	mutex_lock(&iommu_debug_lock);
99
100	bytes = omap_iommu_dump_ctx(obj, p, count);
101	if (bytes < 0)
102		goto err;
103	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
104
105err:
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 tlb_show(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 pagetable_show(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_FOPS_RO(name)						\
232	static const struct file_operations name##_fops = {	        \
233		.open = simple_open,					\
234		.read = debug_read_##name,				\
235		.llseek = generic_file_llseek,				\
236	}
237
238DEBUG_FOPS_RO(regs);
239DEFINE_SHOW_ATTRIBUTE(tlb);
240DEFINE_SHOW_ATTRIBUTE(pagetable);
241
242void omap_iommu_debugfs_add(struct omap_iommu *obj)
243{
244	struct dentry *d;
245
246	if (!iommu_debug_root)
247		return;
248
249	d = debugfs_create_dir(obj->name, iommu_debug_root);
250	obj->debug_dir = d;
251
252	debugfs_create_u32("nr_tlb_entries", 0400, d, &obj->nr_tlb_entries);
253	debugfs_create_file("regs", 0400, d, obj, &regs_fops);
254	debugfs_create_file("tlb", 0400, d, obj, &tlb_fops);
255	debugfs_create_file("pagetable", 0400, d, obj, &pagetable_fops);
256}
257
258void omap_iommu_debugfs_remove(struct omap_iommu *obj)
259{
260	if (!obj->debug_dir)
261		return;
262
263	debugfs_remove_recursive(obj->debug_dir);
264}
265
266void __init omap_iommu_debugfs_init(void)
267{
268	iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
269}
270
271void __exit omap_iommu_debugfs_exit(void)
272{
273	debugfs_remove(iommu_debug_root);
274}
275