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1 /*
2  * debugfs ops for the L1 cache
3  *
4  *  Copyright (C) 2006  Paul Mundt
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/debugfs.h>
13 #include <linux/seq_file.h>
14 #include <asm/processor.h>
15 #include <asm/uaccess.h>
16 #include <asm/cache.h>
17 #include <asm/io.h>
18 
19 enum cache_type {
20 	CACHE_TYPE_ICACHE,
21 	CACHE_TYPE_DCACHE,
22 	CACHE_TYPE_UNIFIED,
23 };
24 
cache_seq_show(struct seq_file * file,void * iter)25 static int __uses_jump_to_uncached cache_seq_show(struct seq_file *file,
26 						  void *iter)
27 {
28 	unsigned int cache_type = (unsigned int)file->private;
29 	struct cache_info *cache;
30 	unsigned int waysize, way, cache_size;
31 	unsigned long ccr, base;
32 	static unsigned long addrstart = 0;
33 
34 	/*
35 	 * Go uncached immediately so we don't skew the results any
36 	 * more than we already are..
37 	 */
38 	jump_to_uncached();
39 
40 	ccr = ctrl_inl(CCR);
41 	if ((ccr & CCR_CACHE_ENABLE) == 0) {
42 		back_to_cached();
43 
44 		seq_printf(file, "disabled\n");
45 		return 0;
46 	}
47 
48 	if (cache_type == CACHE_TYPE_DCACHE) {
49 		base = CACHE_OC_ADDRESS_ARRAY;
50 		cache = &current_cpu_data.dcache;
51 	} else {
52 		base = CACHE_IC_ADDRESS_ARRAY;
53 		cache = &current_cpu_data.icache;
54 	}
55 
56 	/*
57 	 * Due to the amount of data written out (depending on the cache size),
58 	 * we may be iterated over multiple times. In this case, keep track of
59 	 * the entry position in addrstart, and rewind it when we've hit the
60 	 * end of the cache.
61 	 *
62 	 * Likewise, the same code is used for multiple caches, so care must
63 	 * be taken for bouncing addrstart back and forth so the appropriate
64 	 * cache is hit.
65 	 */
66 	cache_size = cache->ways * cache->sets * cache->linesz;
67 	if (((addrstart & 0xff000000) != base) ||
68 	     (addrstart & 0x00ffffff) > cache_size)
69 		addrstart = base;
70 
71 	waysize = cache->sets;
72 
73 	/*
74 	 * If the OC is already in RAM mode, we only have
75 	 * half of the entries to consider..
76 	 */
77 	if ((ccr & CCR_CACHE_ORA) && cache_type == CACHE_TYPE_DCACHE)
78 		waysize >>= 1;
79 
80 	waysize <<= cache->entry_shift;
81 
82 	for (way = 0; way < cache->ways; way++) {
83 		unsigned long addr;
84 		unsigned int line;
85 
86 		seq_printf(file, "-----------------------------------------\n");
87 		seq_printf(file, "Way %d\n", way);
88 		seq_printf(file, "-----------------------------------------\n");
89 
90 		for (addr = addrstart, line = 0;
91 		     addr < addrstart + waysize;
92 		     addr += cache->linesz, line++) {
93 			unsigned long data = ctrl_inl(addr);
94 
95 			/* Check the V bit, ignore invalid cachelines */
96 			if ((data & 1) == 0)
97 				continue;
98 
99 			/* U: Dirty, cache tag is 10 bits up */
100 			seq_printf(file, "%3d: %c 0x%lx\n",
101 				   line, data & 2 ? 'U' : ' ',
102 				   data & 0x1ffffc00);
103 		}
104 
105 		addrstart += cache->way_incr;
106 	}
107 
108 	back_to_cached();
109 
110 	return 0;
111 }
112 
cache_debugfs_open(struct inode * inode,struct file * file)113 static int cache_debugfs_open(struct inode *inode, struct file *file)
114 {
115 	return single_open(file, cache_seq_show, inode->i_private);
116 }
117 
118 static const struct file_operations cache_debugfs_fops = {
119 	.owner		= THIS_MODULE,
120 	.open		= cache_debugfs_open,
121 	.read		= seq_read,
122 	.llseek		= seq_lseek,
123 	.release	= single_release,
124 };
125 
cache_debugfs_init(void)126 static int __init cache_debugfs_init(void)
127 {
128 	struct dentry *dcache_dentry, *icache_dentry;
129 
130 	dcache_dentry = debugfs_create_file("dcache", S_IRUSR, sh_debugfs_root,
131 					    (unsigned int *)CACHE_TYPE_DCACHE,
132 					    &cache_debugfs_fops);
133 	if (!dcache_dentry)
134 		return -ENOMEM;
135 	if (IS_ERR(dcache_dentry))
136 		return PTR_ERR(dcache_dentry);
137 
138 	icache_dentry = debugfs_create_file("icache", S_IRUSR, sh_debugfs_root,
139 					    (unsigned int *)CACHE_TYPE_ICACHE,
140 					    &cache_debugfs_fops);
141 	if (!icache_dentry) {
142 		debugfs_remove(dcache_dentry);
143 		return -ENOMEM;
144 	}
145 	if (IS_ERR(icache_dentry)) {
146 		debugfs_remove(dcache_dentry);
147 		return PTR_ERR(icache_dentry);
148 	}
149 
150 	return 0;
151 }
152 module_init(cache_debugfs_init);
153 
154 MODULE_LICENSE("GPL v2");
155