LXR linux/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
  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_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 */
  80void 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
 100int 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
 121void 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
 134void __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 */
 143static void udbg_console_write(struct console *con, const char *s,
 144                unsigned int n)
 145{
 146        udbg_write(s, n);
 147}
 148
 149static 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 */
 160void __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 */
 177console_initcall(register_udbg_console);
 178#endif
 179