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 		bytes = snprintf(p, maxcol, str, __stringify(name),	\
36 				 iommu_read_reg(obj, MMU_##name));	\
37 		p += bytes;						\
38 		len -= bytes;						\
39 		if (len < maxcol)					\
40 			goto out;					\
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 	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
102 
103 	mutex_unlock(&iommu_debug_lock);
104 	kfree(buf);
105 
106 	return bytes;
107 }
108 
109 static int
110 __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
111 {
112 	int i;
113 	struct iotlb_lock saved;
114 	struct cr_regs tmp;
115 	struct cr_regs *p = crs;
116 
117 	pm_runtime_get_sync(obj->dev);
118 	iotlb_lock_get(obj, &saved);
119 
120 	for_each_iotlb_cr(obj, num, i, tmp) {
121 		if (!iotlb_cr_valid(&tmp))
122 			continue;
123 		*p++ = tmp;
124 	}
125 
126 	iotlb_lock_set(obj, &saved);
127 	pm_runtime_put_sync(obj->dev);
128 
129 	return  p - crs;
130 }
131 
132 static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
133 			     struct seq_file *s)
134 {
135 	seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
136 		   (cr->cam & MMU_CAM_P) ? 1 : 0);
137 	return 0;
138 }
139 
140 static size_t omap_dump_tlb_entries(struct omap_iommu *obj, struct seq_file *s)
141 {
142 	int i, num;
143 	struct cr_regs *cr;
144 
145 	num = obj->nr_tlb_entries;
146 
147 	cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
148 	if (!cr)
149 		return 0;
150 
151 	num = __dump_tlb_entries(obj, cr, num);
152 	for (i = 0; i < num; i++)
153 		iotlb_dump_cr(obj, cr + i, s);
154 	kfree(cr);
155 
156 	return 0;
157 }
158 
159 static int tlb_show(struct seq_file *s, void *data)
160 {
161 	struct omap_iommu *obj = s->private;
162 
163 	if (is_omap_iommu_detached(obj))
164 		return -EPERM;
165 
166 	mutex_lock(&iommu_debug_lock);
167 
168 	seq_printf(s, "%8s %8s\n", "cam:", "ram:");
169 	seq_puts(s, "-----------------------------------------\n");
170 	omap_dump_tlb_entries(obj, s);
171 
172 	mutex_unlock(&iommu_debug_lock);
173 
174 	return 0;
175 }
176 
177 static void dump_ioptable(struct seq_file *s)
178 {
179 	int i, j;
180 	u32 da;
181 	u32 *iopgd, *iopte;
182 	struct omap_iommu *obj = s->private;
183 
184 	spin_lock(&obj->page_table_lock);
185 
186 	iopgd = iopgd_offset(obj, 0);
187 	for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
188 		if (!*iopgd)
189 			continue;
190 
191 		if (!(*iopgd & IOPGD_TABLE)) {
192 			da = i << IOPGD_SHIFT;
193 			seq_printf(s, "1: 0x%08x 0x%08x\n", da, *iopgd);
194 			continue;
195 		}
196 
197 		iopte = iopte_offset(iopgd, 0);
198 		for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
199 			if (!*iopte)
200 				continue;
201 
202 			da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
203 			seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
204 		}
205 	}
206 
207 	spin_unlock(&obj->page_table_lock);
208 }
209 
210 static int pagetable_show(struct seq_file *s, void *data)
211 {
212 	struct omap_iommu *obj = s->private;
213 
214 	if (is_omap_iommu_detached(obj))
215 		return -EPERM;
216 
217 	mutex_lock(&iommu_debug_lock);
218 
219 	seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
220 	seq_puts(s, "--------------------------\n");
221 	dump_ioptable(s);
222 
223 	mutex_unlock(&iommu_debug_lock);
224 
225 	return 0;
226 }
227 
228 #define DEBUG_FOPS_RO(name)						\
229 	static const struct file_operations name##_fops = {	        \
230 		.open = simple_open,					\
231 		.read = debug_read_##name,				\
232 		.llseek = generic_file_llseek,				\
233 	}
234 
235 DEBUG_FOPS_RO(regs);
236 DEFINE_SHOW_ATTRIBUTE(tlb);
237 DEFINE_SHOW_ATTRIBUTE(pagetable);
238 
239 void omap_iommu_debugfs_add(struct omap_iommu *obj)
240 {
241 	struct dentry *d;
242 
243 	if (!iommu_debug_root)
244 		return;
245 
246 	d = debugfs_create_dir(obj->name, iommu_debug_root);
247 	obj->debug_dir = d;
248 
249 	debugfs_create_u32("nr_tlb_entries", 0400, d, &obj->nr_tlb_entries);
250 	debugfs_create_file("regs", 0400, d, obj, &regs_fops);
251 	debugfs_create_file("tlb", 0400, d, obj, &tlb_fops);
252 	debugfs_create_file("pagetable", 0400, d, obj, &pagetable_fops);
253 }
254 
255 void omap_iommu_debugfs_remove(struct omap_iommu *obj)
256 {
257 	if (!obj->debug_dir)
258 		return;
259 
260 	debugfs_remove_recursive(obj->debug_dir);
261 }
262 
263 void __init omap_iommu_debugfs_init(void)
264 {
265 	iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
266 }
267 
268 void __exit omap_iommu_debugfs_exit(void)
269 {
270 	debugfs_remove(iommu_debug_root);
271 }
272