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 <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_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 */
  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
 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
 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
 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  */
 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  */
 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