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  
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_CPM)
53  	udbg_init_cpm();
54  #elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
55  	udbg_init_usbgecko();
56  #elif defined(CONFIG_PPC_EARLY_DEBUG_MEMCONS)
57  	/* In memory console */
58  	udbg_init_memcons();
59  #elif defined(CONFIG_PPC_EARLY_DEBUG_EHV_BC)
60  	udbg_init_ehv_bc();
61  #elif defined(CONFIG_PPC_EARLY_DEBUG_PS3GELIC)
62  	udbg_init_ps3gelic();
63  #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_RAW)
64  	udbg_init_debug_opal_raw();
65  #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI)
66  	udbg_init_debug_opal_hvsi();
67  #elif defined(CONFIG_PPC_EARLY_DEBUG_16550)
68  	udbg_init_debug_16550();
69  #endif
70  
71  #ifdef CONFIG_PPC_EARLY_DEBUG
72  	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
73  
74  	register_early_udbg_console();
75  #endif
76  }
77  
78  /* udbg library, used by xmon et al */
udbg_puts(const char * s)79  void udbg_puts(const char *s)
80  {
81  	if (udbg_putc) {
82  		char c;
83  
84  		if (s && *s != '\0') {
85  			while ((c = *s++) != '\0')
86  				udbg_putc(c);
87  		}
88  
89  		if (udbg_flush)
90  			udbg_flush();
91  	}
92  #if 0
93  	else {
94  		printk("%s", s);
95  	}
96  #endif
97  }
98  
udbg_write(const char * s,int n)99  int udbg_write(const char *s, int n)
100  {
101  	int remain = n;
102  	char c;
103  
104  	if (!udbg_putc)
105  		return 0;
106  
107  	if (s && *s != '\0') {
108  		while (((c = *s++) != '\0') && (remain-- > 0)) {
109  			udbg_putc(c);
110  		}
111  	}
112  
113  	if (udbg_flush)
114  		udbg_flush();
115  
116  	return n - remain;
117  }
118  
119  #define UDBG_BUFSIZE 256
udbg_printf(const char * fmt,...)120  void udbg_printf(const char *fmt, ...)
121  {
122  	if (udbg_putc) {
123  		char buf[UDBG_BUFSIZE];
124  		va_list args;
125  
126  		va_start(args, fmt);
127  		vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
128  		udbg_puts(buf);
129  		va_end(args);
130  	}
131  }
132  
udbg_progress(char * s,unsigned short hex)133  void __init udbg_progress(char *s, unsigned short hex)
134  {
135  	udbg_puts(s);
136  	udbg_puts("\n");
137  }
138  
139  /*
140   * Early boot console based on udbg
141   */
udbg_console_write(struct console * con,const char * s,unsigned int n)142  static void udbg_console_write(struct console *con, const char *s,
143  		unsigned int n)
144  {
145  	udbg_write(s, n);
146  }
147  
148  static struct console udbg_console = {
149  	.name	= "udbg",
150  	.write	= udbg_console_write,
151  	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
152  	.index	= 0,
153  };
154  
155  /*
156   * Called by setup_system after ppc_md->probe and ppc_md->early_init.
157   * Call it again after setting udbg_putc in ppc_md->setup_arch.
158   */
register_early_udbg_console(void)159  void __init register_early_udbg_console(void)
160  {
161  	if (early_console)
162  		return;
163  
164  	if (!udbg_putc)
165  		return;
166  
167  	if (strstr(boot_command_line, "udbg-immortal")) {
168  		printk(KERN_INFO "early console immortal !\n");
169  		udbg_console.flags &= ~CON_BOOT;
170  	}
171  	early_console = &udbg_console;
172  	register_console(&udbg_console);
173  }
174  
175  #if 0   /* if you want to use this as a regular output console */
176  console_initcall(register_udbg_console);
177  #endif
178