xref: /openbmc/u-boot/common/iotrace.c (revision 5ff10aa7)
1 /*
2  * Copyright (c) 2014 Google, Inc.
3  *
4  * SPDX-License-Identifier:     GPL-2.0+
5  */
6 
7 #define IOTRACE_IMPL
8 
9 #include <common.h>
10 #include <asm/io.h>
11 
12 DECLARE_GLOBAL_DATA_PTR;
13 
14 /* Support up to the machine word length for now */
15 typedef ulong iovalue_t;
16 
17 enum iotrace_flags {
18 	IOT_8 = 0,
19 	IOT_16,
20 	IOT_32,
21 
22 	IOT_READ = 0 << 3,
23 	IOT_WRITE = 1 << 3,
24 };
25 
26 /**
27  * struct iotrace_record - Holds a single I/O trace record
28  *
29  * @flags: I/O access type
30  * @addr: Address of access
31  * @value: Value written or read
32  */
33 struct iotrace_record {
34 	enum iotrace_flags flags;
35 	phys_addr_t addr;
36 	iovalue_t value;
37 };
38 
39 /**
40  * struct iotrace - current trace status and checksum
41  *
42  * @start:	Start address of iotrace buffer
43  * @size:	Size of iotrace buffer in bytes
44  * @offset:	Current write offset into iotrace buffer
45  * @crc32:	Current value of CRC chceksum of trace records
46  * @enabled:	true if enabled, false if disabled
47  */
48 static struct iotrace {
49 	ulong start;
50 	ulong size;
51 	ulong offset;
52 	u32 crc32;
53 	bool enabled;
54 } iotrace;
55 
56 static void add_record(int flags, const void *ptr, ulong value)
57 {
58 	struct iotrace_record srec, *rec = &srec;
59 
60 	/*
61 	 * We don't support iotrace before relocation. Since the trace buffer
62 	 * is set up by a command, it can't be enabled at present. To change
63 	 * this we would need to set the iotrace buffer at build-time. See
64 	 * lib/trace.c for how this might be done if you are interested.
65 	 */
66 	if (!(gd->flags & GD_FLG_RELOC) || !iotrace.enabled)
67 		return;
68 
69 	/* Store it if there is room */
70 	if (iotrace.offset + sizeof(*rec) < iotrace.size) {
71 		rec = (struct iotrace_record *)map_sysmem(
72 					iotrace.start + iotrace.offset,
73 					sizeof(value));
74 	}
75 
76 	rec->flags = flags;
77 	rec->addr = map_to_sysmem(ptr);
78 	rec->value = value;
79 
80 	/* Update our checksum */
81 	iotrace.crc32 = crc32(iotrace.crc32, (unsigned char *)rec,
82 			      sizeof(*rec));
83 
84 	iotrace.offset += sizeof(struct iotrace_record);
85 }
86 
87 u32 iotrace_readl(const void *ptr)
88 {
89 	u32 v;
90 
91 	v = readl(ptr);
92 	add_record(IOT_32 | IOT_READ, ptr, v);
93 
94 	return v;
95 }
96 
97 void iotrace_writel(ulong value, const void *ptr)
98 {
99 	add_record(IOT_32 | IOT_WRITE, ptr, value);
100 	writel(value, ptr);
101 }
102 
103 u16 iotrace_readw(const void *ptr)
104 {
105 	u32 v;
106 
107 	v = readw(ptr);
108 	add_record(IOT_16 | IOT_READ, ptr, v);
109 
110 	return v;
111 }
112 
113 void iotrace_writew(ulong value, const void *ptr)
114 {
115 	add_record(IOT_16 | IOT_WRITE, ptr, value);
116 	writew(value, ptr);
117 }
118 
119 u8 iotrace_readb(const void *ptr)
120 {
121 	u32 v;
122 
123 	v = readb(ptr);
124 	add_record(IOT_8 | IOT_READ, ptr, v);
125 
126 	return v;
127 }
128 
129 void iotrace_writeb(ulong value, const void *ptr)
130 {
131 	add_record(IOT_8 | IOT_WRITE, ptr, value);
132 	writeb(value, ptr);
133 }
134 
135 void iotrace_reset_checksum(void)
136 {
137 	iotrace.crc32 = 0;
138 }
139 
140 u32 iotrace_get_checksum(void)
141 {
142 	return iotrace.crc32;
143 }
144 
145 void iotrace_set_enabled(int enable)
146 {
147 	iotrace.enabled = enable;
148 }
149 
150 int iotrace_get_enabled(void)
151 {
152 	return iotrace.enabled;
153 }
154 
155 void iotrace_set_buffer(ulong start, ulong size)
156 {
157 	iotrace.start = start;
158 	iotrace.size = size;
159 	iotrace.offset = 0;
160 	iotrace.crc32 = 0;
161 }
162 
163 void iotrace_get_buffer(ulong *start, ulong *size, ulong *offset, ulong *count)
164 {
165 	*start = iotrace.start;
166 	*size = iotrace.size;
167 	*offset = iotrace.offset;
168 	*count = iotrace.offset / sizeof(struct iotrace_record);
169 }
170