arch/powerpc/kernel/udbg.c

   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  */
  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_PAS_REALMODE)
  43         udbg_init_pas_realmode();
  44 #elif defined(CONFIG_PPC_EARLY_DEBUG_BOOTX)
  45         udbg_init_btext();
  46 #elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
  47         /* PPC44x debug */
  48         udbg_init_44x_as1();
  49 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
  50         udbg_init_cpm();
  51 #elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
  52         udbg_init_usbgecko();
  53 #elif defined(CONFIG_PPC_EARLY_DEBUG_MEMCONS)
  54         /* In memory console */
  55         udbg_init_memcons();
  56 #elif defined(CONFIG_PPC_EARLY_DEBUG_EHV_BC)
  57         udbg_init_ehv_bc();
  58 #elif defined(CONFIG_PPC_EARLY_DEBUG_PS3GELIC)
  59         udbg_init_ps3gelic();
  60 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_RAW)
  61         udbg_init_debug_opal_raw();
  62 #elif defined(CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI)
  63         udbg_init_debug_opal_hvsi();
  64 #elif defined(CONFIG_PPC_EARLY_DEBUG_16550)
  65         udbg_init_debug_16550();
  66 #endif
  67
  68 #ifdef CONFIG_PPC_EARLY_DEBUG
  69         console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
  70
  71         register_early_udbg_console();
  72 #endif
  73 }
  74
  75 /* udbg library, used by xmon et al */
  76 void udbg_puts(const char *s)
  77 {
  78         if (udbg_putc) {
  79                 char c;
  80
  81                 if (s && *s != '\0') {
  82                         while ((c = *s++) != '\0')
  83                                 udbg_putc(c);
  84                 }
  85
  86                 if (udbg_flush)
  87                         udbg_flush();
  88         }
  89 #if 0
  90         else {
  91                 printk("%s", s);
  92         }
  93 #endif
  94 }
  95
  96 int udbg_write(const char *s, int n)
  97 {
  98         int remain = n;
  99         char c;
 100
 101         if (!udbg_putc)
 102                 return 0;
 103
 104         if (s && *s != '\0') {
 105                 while (((c = *s++) != '\0') && (remain-- > 0)) {
 106                         udbg_putc(c);
 107                 }
 108         }
 109
 110         if (udbg_flush)
 111                 udbg_flush();
 112
 113         return n - remain;
 114 }
 115
 116 #define UDBG_BUFSIZE 256
 117 void udbg_printf(const char *fmt, ...)
 118 {
 119         if (udbg_putc) {
 120                 char buf[UDBG_BUFSIZE];
 121                 va_list args;
 122
 123                 va_start(args, fmt);
 124                 vsnprintf(buf, UDBG_BUFSIZE, fmt, args);
 125                 udbg_puts(buf);
 126                 va_end(args);
 127         }
 128 }
 129
 130 void __init udbg_progress(char *s, unsigned short hex)
 131 {
 132         udbg_puts(s);
 133         udbg_puts("\n");
 134 }
 135
 136 /*
 137  * Early boot console based on udbg
 138  */
 139 static void udbg_console_write(struct console *con, const char *s,
 140                 unsigned int n)
 141 {
 142         udbg_write(s, n);
 143 }
 144
 145 static struct console udbg_console = {
 146         .name   = "udbg",
 147         .write  = udbg_console_write,
 148         .flags  = CON_PRINTBUFFER | CON_ENABLED | CON_BOOT | CON_ANYTIME,
 149         .index  = 0,
 150 };
 151
 152 /*
 153  * Called by setup_system after ppc_md->probe and ppc_md->early_init.
 154  * Call it again after setting udbg_putc in ppc_md->setup_arch.
 155  */
 156 void __init register_early_udbg_console(void)
 157 {
 158         if (early_console)
 159                 return;
 160
 161         if (!udbg_putc)
 162                 return;
 163
 164         if (strstr(boot_command_line, "udbg-immortal")) {
 165                 printk(KERN_INFO "early console immortal !\n");
 166                 udbg_console.flags &= ~CON_BOOT;
 167         }
 168         early_console = &udbg_console;
 169         register_console(&udbg_console);
 170 }
 171
 172 #if 0   /* if you want to use this as a regular output console */
 173 console_initcall(register_udbg_console);
 174 #endif