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
is_omap_iommu_detached(struct omap_iommu * obj)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
omap2_iommu_dump_ctx(struct omap_iommu * obj,char * buf,ssize_t len)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
omap_iommu_dump_ctx(struct omap_iommu * obj,char * buf,ssize_t bytes)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
debug_read_regs(struct file * file,char __user * userbuf,size_t count,loff_t * ppos)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
__dump_tlb_entries(struct omap_iommu * obj,struct cr_regs * crs,int num)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
iotlb_dump_cr(struct omap_iommu * obj,struct cr_regs * cr,struct seq_file * s)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
omap_dump_tlb_entries(struct omap_iommu * obj,struct seq_file * s)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
tlb_show(struct seq_file * s,void * data)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
dump_ioptable(struct seq_file * s)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
pagetable_show(struct seq_file * s,void * data)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
omap_iommu_debugfs_add(struct omap_iommu * obj)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, ®s_fops);
254 debugfs_create_file("tlb", 0400, d, obj, &tlb_fops);
255 debugfs_create_file("pagetable", 0400, d, obj, &pagetable_fops);
256 }
257
omap_iommu_debugfs_remove(struct omap_iommu * obj)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
omap_iommu_debugfs_init(void)266 void __init omap_iommu_debugfs_init(void)
267 {
268 iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
269 }
270
omap_iommu_debugfs_exit(void)271 void __exit omap_iommu_debugfs_exit(void)
272 {
273 debugfs_remove(iommu_debug_root);
274 }
275