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 <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
16 void (*udbg_putc)(char c);
17 void (*udbg_flush)(void);
18 int (*udbg_getc)(void);
19 int (*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 */
udbg_early_init(void)25 void __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_RTAS_CONSOLE)
40 /* RTAS console debug */
41 udbg_init_rtas_console();
42 #elif defined(CONFIG_PPC_EARLY_DEBUG_MAPLE)
43 /* Maple real mode debug */
44 udbg_init_maple_realmode();
45 #elif defined(CONFIG_PPC_EARLY_DEBUG_PAS_REALMODE)
46 udbg_init_pas_realmode();
47 #elif defined(CONFIG_PPC_EARLY_DEBUG_BOOTX)
48 udbg_init_btext();
49 #elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
50 /* PPC44x debug */
51 udbg_init_44x_as1();
52 #elif defined(CONFIG_PPC_EARLY_DEBUG_40x)
53 /* PPC40x debug */
54 udbg_init_40x_realmode();
55 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
56 udbg_init_cpm();
57 #elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
58 udbg_init_usbgecko();
59 #elif defined(CONFIG_PPC_EARLY_DEBUG_MEMCONS)
60 /* In memory console */
61 udbg_init_memcons();
62 #elif defined(CONFIG_PPC_EARLY_DEBUG_EHV_BC)
63 udbg_init_ehv_bc();
64 #elif defined(CONFIG_PPC_EARLY_DEBUG_PS3GELIC)
65 udbg_init_ps3gelic();
66 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_RAW)
67 udbg_init_debug_opal_raw();
68 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI)
69 udbg_init_debug_opal_hvsi();
70 #endif
71
72 #ifdef CONFIG_PPC_EARLY_DEBUG
73 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
74
75 register_early_udbg_console();
76 #endif
77 }
78
79 /* udbg library, used by xmon et al */
udbg_puts(const char * s)80 void udbg_puts(const char *s)
81 {
82 if (udbg_putc) {
83 char c;
84
85 if (s && *s != '\0') {
86 while ((c = *s++) != '\0')
87 udbg_putc(c);
88 }
89
90 if (udbg_flush)
91 udbg_flush();
92 }
93 #if 0
94 else {
95 printk("%s", s);
96 }
97 #endif
98 }
99
udbg_write(const char * s,int n)100 int udbg_write(const char *s, int n)
101 {
102 int remain = n;
103 char c;
104
105 if (!udbg_putc)
106 return 0;
107
108 if (s && *s != '\0') {
109 while (((c = *s++) != '\0') && (remain-- > 0)) {
110 udbg_putc(c);
111 }
112 }
113
114 if (udbg_flush)
115 udbg_flush();
116
117 return n - remain;
118 }
119
120 #define UDBG_BUFSIZE 256
udbg_printf(const char * fmt,...)121 void udbg_printf(const char *fmt, ...)
122 {
123 if (udbg_putc) {
124 char buf[UDBG_BUFSIZE];
125 va_list args;
126
127 va_start(args, fmt);
128 vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
129 udbg_puts(buf);
130 va_end(args);
131 }
132 }
133
udbg_progress(char * s,unsigned short hex)134 void __init udbg_progress(char *s, unsigned short hex)
135 {
136 udbg_puts(s);
137 udbg_puts("\n");
138 }
139
140 /*
141 * Early boot console based on udbg
142 */
udbg_console_write(struct console * con,const char * s,unsigned int n)143 static void udbg_console_write(struct console *con, const char *s,
144 unsigned int n)
145 {
146 udbg_write(s, n);
147 }
148
149 static struct console udbg_console = {
150 .name = "udbg",
151 .write = udbg_console_write,
152 .flags = CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
153 .index = 0,
154 };
155
156 /*
157 * Called by setup_system after ppc_md->probe and ppc_md->early_init.
158 * Call it again after setting udbg_putc in ppc_md->setup_arch.
159 */
register_early_udbg_console(void)160 void __init register_early_udbg_console(void)
161 {
162 if (early_console)
163 return;
164
165 if (!udbg_putc)
166 return;
167
168 if (strstr(boot_command_line, "udbg-immortal")) {
169 printk(KERN_INFO "early console immortal !\n");
170 udbg_console.flags &= ~CON_BOOT;
171 }
172 early_console = &udbg_console;
173 register_console(&udbg_console);
174 }
175
176 #if 0 /* if you want to use this as a regular output console */
177 console_initcall(register_udbg_console);
178 #endif
179