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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * polling mode stateless debugging stuff, originally for NS16550 Serial Ports
4 *
5 * c 2001 PPC 64 Team, IBM Corp
6 */
7
8#include <linux/stdarg.h>
9#include <linux/types.h>
10#include <linux/sched.h>
11#include <linux/console.h>
12#include <linux/init.h>
13#include <asm/processor.h>
14#include <asm/udbg.h>
15
16void (*udbg_putc)(char c);
17void (*udbg_flush)(void);
18int (*udbg_getc)(void);
19int (*udbg_getc_poll)(void);
20
21/*
22 * Early debugging facilities. You can enable _one_ of these via .config,
23 * if you do so your kernel _will not boot_ on anything else. Be careful.
24 */
25void __init udbg_early_init(void)
26{
27#if defined(CONFIG_PPC_EARLY_DEBUG_LPAR)
28 /* For LPAR machines that have an HVC console on vterm 0 */
29 udbg_init_debug_lpar();
30#elif defined(CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI)
31 /* For LPAR machines that have an HVSI console on vterm 0 */
32 udbg_init_debug_lpar_hvsi();
33#elif defined(CONFIG_PPC_EARLY_DEBUG_G5)
34 /* For use on Apple G5 machines */
35 udbg_init_pmac_realmode();
36#elif defined(CONFIG_PPC_EARLY_DEBUG_RTAS_PANEL)
37 /* RTAS panel debug */
38 udbg_init_rtas_panel();
39#elif defined(CONFIG_PPC_EARLY_DEBUG_PAS_REALMODE)
40 udbg_init_pas_realmode();
41#elif defined(CONFIG_PPC_EARLY_DEBUG_BOOTX)
42 udbg_init_btext();
43#elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
44 /* PPC44x debug */
45 udbg_init_44x_as1();
46#elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
47 udbg_init_cpm();
48#elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
49 udbg_init_usbgecko();
50#elif defined(CONFIG_PPC_EARLY_DEBUG_MEMCONS)
51 /* In memory console */
52 udbg_init_memcons();
53#elif defined(CONFIG_PPC_EARLY_DEBUG_EHV_BC)
54 udbg_init_ehv_bc();
55#elif defined(CONFIG_PPC_EARLY_DEBUG_PS3GELIC)
56 udbg_init_ps3gelic();
57#elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_RAW)
58 udbg_init_debug_opal_raw();
59#elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI)
60 udbg_init_debug_opal_hvsi();
61#elif defined(CONFIG_PPC_EARLY_DEBUG_16550)
62 udbg_init_debug_16550();
63#endif
64
65#ifdef CONFIG_PPC_EARLY_DEBUG
66 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
67
68 register_early_udbg_console();
69#endif
70}
71
72/* udbg library, used by xmon et al */
73void udbg_puts(const char *s)
74{
75 if (udbg_putc) {
76 char c;
77
78 if (s && *s != '\0') {
79 while ((c = *s++) != '\0')
80 udbg_putc(c);
81 }
82
83 if (udbg_flush)
84 udbg_flush();
85 }
86#if 0
87 else {
88 printk("%s", s);
89 }
90#endif
91}
92
93int udbg_write(const char *s, int n)
94{
95 int remain = n;
96 char c;
97
98 if (!udbg_putc)
99 return 0;
100
101 if (s && *s != '\0') {
102 while (((c = *s++) != '\0') && (remain-- > 0)) {
103 udbg_putc(c);
104 }
105 }
106
107 if (udbg_flush)
108 udbg_flush();
109
110 return n - remain;
111}
112
113#define UDBG_BUFSIZE 256
114void udbg_printf(const char *fmt, ...)
115{
116 if (udbg_putc) {
117 char buf[UDBG_BUFSIZE];
118 va_list args;
119
120 va_start(args, fmt);
121 vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
122 udbg_puts(buf);
123 va_end(args);
124 }
125}
126
127void __init udbg_progress(char *s, unsigned short hex)
128{
129 udbg_puts(s);
130 udbg_puts("\n");
131}
132
133/*
134 * Early boot console based on udbg
135 */
136static void udbg_console_write(struct console *con, const char *s,
137 unsigned int n)
138{
139 udbg_write(s, n);
140}
141
142static struct console udbg_console = {
143 .name = "udbg",
144 .write = udbg_console_write,
145 .flags = CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
146 .index = 0,
147};
148
149/*
150 * Called by setup_system after ppc_md->probe and ppc_md->early_init.
151 * Call it again after setting udbg_putc in ppc_md->setup_arch.
152 */
153void __init register_early_udbg_console(void)
154{
155 if (early_console)
156 return;
157
158 if (!udbg_putc)
159 return;
160
161 if (strstr(boot_command_line, "udbg-immortal")) {
162 printk(KERN_INFO "early console immortal !\n");
163 udbg_console.flags &= ~CON_BOOT;
164 }
165 early_console = &udbg_console;
166 register_console(&udbg_console);
167}
168
169#if 0 /* if you want to use this as a regular output console */
170console_initcall(register_udbg_console);
171#endif