xref: /openbmc/linux/arch/sh/mm/tlb-debugfs.c (revision e2c75e76)
1 /*
2  * arch/sh/mm/tlb-debugfs.c
3  *
4  * debugfs ops for SH-4 ITLB/UTLBs.
5  *
6  * Copyright (C) 2010  Matt Fleming
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file "COPYING" in the main directory of this archive
10  * for more details.
11  */
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/debugfs.h>
15 #include <linux/seq_file.h>
16 #include <asm/processor.h>
17 #include <asm/mmu_context.h>
18 #include <asm/tlbflush.h>
19 
20 enum tlb_type {
21 	TLB_TYPE_ITLB,
22 	TLB_TYPE_UTLB,
23 };
24 
25 static struct {
26 	int bits;
27 	const char *size;
28 } tlb_sizes[] = {
29 	{ 0x0, "  1KB" },
30 	{ 0x1, "  4KB" },
31 	{ 0x2, "  8KB" },
32 	{ 0x4, " 64KB" },
33 	{ 0x5, "256KB" },
34 	{ 0x7, "  1MB" },
35 	{ 0x8, "  4MB" },
36 	{ 0xc, " 64MB" },
37 };
38 
39 static int tlb_seq_show(struct seq_file *file, void *iter)
40 {
41 	unsigned int tlb_type = (unsigned int)file->private;
42 	unsigned long addr1, addr2, data1, data2;
43 	unsigned long flags;
44 	unsigned long mmucr;
45 	unsigned int nentries, entry;
46 	unsigned int urb;
47 
48 	mmucr = __raw_readl(MMUCR);
49 	if ((mmucr & 0x1) == 0) {
50 		seq_printf(file, "address translation disabled\n");
51 		return 0;
52 	}
53 
54 	if (tlb_type == TLB_TYPE_ITLB) {
55 		addr1 = MMU_ITLB_ADDRESS_ARRAY;
56 		addr2 = MMU_ITLB_ADDRESS_ARRAY2;
57 		data1 = MMU_ITLB_DATA_ARRAY;
58 		data2 = MMU_ITLB_DATA_ARRAY2;
59 		nentries = 4;
60 	} else {
61 		addr1 = MMU_UTLB_ADDRESS_ARRAY;
62 		addr2 = MMU_UTLB_ADDRESS_ARRAY2;
63 		data1 = MMU_UTLB_DATA_ARRAY;
64 		data2 = MMU_UTLB_DATA_ARRAY2;
65 		nentries = 64;
66 	}
67 
68 	local_irq_save(flags);
69 	jump_to_uncached();
70 
71 	urb = (mmucr & MMUCR_URB) >> MMUCR_URB_SHIFT;
72 
73 	/* Make the "entry >= urb" test fail. */
74 	if (urb == 0)
75 		urb = MMUCR_URB_NENTRIES + 1;
76 
77 	if (tlb_type == TLB_TYPE_ITLB) {
78 		addr1 = MMU_ITLB_ADDRESS_ARRAY;
79 		addr2 = MMU_ITLB_ADDRESS_ARRAY2;
80 		data1 = MMU_ITLB_DATA_ARRAY;
81 		data2 = MMU_ITLB_DATA_ARRAY2;
82 		nentries = 4;
83 	} else {
84 		addr1 = MMU_UTLB_ADDRESS_ARRAY;
85 		addr2 = MMU_UTLB_ADDRESS_ARRAY2;
86 		data1 = MMU_UTLB_DATA_ARRAY;
87 		data2 = MMU_UTLB_DATA_ARRAY2;
88 		nentries = 64;
89 	}
90 
91 	seq_printf(file, "entry:     vpn        ppn     asid  size valid wired\n");
92 
93 	for (entry = 0; entry < nentries; entry++) {
94 		unsigned long vpn, ppn, asid, size;
95 		unsigned long valid;
96 		unsigned long val;
97 		const char *sz = "    ?";
98 		int i;
99 
100 		val = __raw_readl(addr1 | (entry << MMU_TLB_ENTRY_SHIFT));
101 		ctrl_barrier();
102 		vpn = val & 0xfffffc00;
103 		valid = val & 0x100;
104 
105 		val = __raw_readl(addr2 | (entry << MMU_TLB_ENTRY_SHIFT));
106 		ctrl_barrier();
107 		asid = val & MMU_CONTEXT_ASID_MASK;
108 
109 		val = __raw_readl(data1 | (entry << MMU_TLB_ENTRY_SHIFT));
110 		ctrl_barrier();
111 		ppn = (val & 0x0ffffc00) << 4;
112 
113 		val = __raw_readl(data2 | (entry << MMU_TLB_ENTRY_SHIFT));
114 		ctrl_barrier();
115 		size = (val & 0xf0) >> 4;
116 
117 		for (i = 0; i < ARRAY_SIZE(tlb_sizes); i++) {
118 			if (tlb_sizes[i].bits == size)
119 				break;
120 		}
121 
122 		if (i != ARRAY_SIZE(tlb_sizes))
123 			sz = tlb_sizes[i].size;
124 
125 		seq_printf(file, "%2d:    0x%08lx 0x%08lx %5lu %s   %s     %s\n",
126 			   entry, vpn, ppn, asid,
127 			   sz, valid ? "V" : "-",
128 			   (urb <= entry) ? "W" : "-");
129 	}
130 
131 	back_to_cached();
132 	local_irq_restore(flags);
133 
134 	return 0;
135 }
136 
137 static int tlb_debugfs_open(struct inode *inode, struct file *file)
138 {
139 	return single_open(file, tlb_seq_show, inode->i_private);
140 }
141 
142 static const struct file_operations tlb_debugfs_fops = {
143 	.owner		= THIS_MODULE,
144 	.open		= tlb_debugfs_open,
145 	.read		= seq_read,
146 	.llseek		= seq_lseek,
147 	.release	= single_release,
148 };
149 
150 static int __init tlb_debugfs_init(void)
151 {
152 	struct dentry *itlb, *utlb;
153 
154 	itlb = debugfs_create_file("itlb", S_IRUSR, arch_debugfs_dir,
155 				   (unsigned int *)TLB_TYPE_ITLB,
156 				   &tlb_debugfs_fops);
157 	if (unlikely(!itlb))
158 		return -ENOMEM;
159 
160 	utlb = debugfs_create_file("utlb", S_IRUSR, arch_debugfs_dir,
161 				   (unsigned int *)TLB_TYPE_UTLB,
162 				   &tlb_debugfs_fops);
163 	if (unlikely(!utlb)) {
164 		debugfs_remove(itlb);
165 		return -ENOMEM;
166 	}
167 
168 	return 0;
169 }
170 module_init(tlb_debugfs_init);
171 
172 MODULE_LICENSE("GPL v2");
173