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 
21 static DEFINE_MUTEX(iommu_debug_lock);
22 
23 static struct dentry *iommu_debug_root;
24 
25 static 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 
43 static ssize_t
44 omap2_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);
64 out:
65 	return p - buf;
66 }
67 
68 static 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 
83 static 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 
105 err:
106 	mutex_unlock(&iommu_debug_lock);
107 	kfree(buf);
108 
109 	return bytes;
110 }
111 
112 static 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 
135 static 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 
143 static 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 
162 static 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 
180 static 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 
213 static 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 
238 DEBUG_FOPS_RO(regs);
239 DEFINE_SHOW_ATTRIBUTE(tlb);
240 DEFINE_SHOW_ATTRIBUTE(pagetable);
241 
242 void 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 
258 void 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 
266 void __init omap_iommu_debugfs_init(void)
267 {
268 	iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
269 }
270 
271 void __exit omap_iommu_debugfs_exit(void)
272 {
273 	debugfs_remove(iommu_debug_root);
274 }
275