diff options
Diffstat (limited to 'arch/s390/boot/printk.c')
| -rw-r--r-- | arch/s390/boot/printk.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/arch/s390/boot/printk.c b/arch/s390/boot/printk.c new file mode 100644 index 000000000000..8cf6331bc060 --- /dev/null +++ b/arch/s390/boot/printk.c @@ -0,0 +1,298 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/stdarg.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <asm/stacktrace.h> +#include <asm/boot_data.h> +#include <asm/sections.h> +#include <asm/lowcore.h> +#include <asm/setup.h> +#include <asm/timex.h> +#include <asm/sclp.h> +#include <asm/uv.h> +#include "boot.h" + +int boot_console_loglevel = CONFIG_CONSOLE_LOGLEVEL_DEFAULT; +bool boot_ignore_loglevel; +char __bootdata(boot_rb)[PAGE_SIZE * 2]; +bool __bootdata(boot_earlyprintk); +size_t __bootdata(boot_rb_off); +char __bootdata(bootdebug_filter)[128]; +bool __bootdata(bootdebug); + +static void boot_rb_add(const char *str, size_t len) +{ + /* leave double '\0' in the end */ + size_t avail = sizeof(boot_rb) - boot_rb_off - 1; + + /* store strings separated by '\0' */ + if (len + 1 > avail) + boot_rb_off = 0; + strcpy(boot_rb + boot_rb_off, str); + boot_rb_off += len + 1; +} + +static void print_rb_entry(const char *str) +{ + sclp_early_printk(printk_skip_level(str)); +} + +static bool debug_messages_printed(void) +{ + return boot_earlyprintk && (boot_ignore_loglevel || boot_console_loglevel > LOGLEVEL_DEBUG); +} + +void boot_rb_dump(void) +{ + if (debug_messages_printed()) + return; + sclp_early_printk("Boot messages ring buffer:\n"); + boot_rb_foreach(print_rb_entry); +} + +const char hex_asc[] = "0123456789abcdef"; + +static char *as_hex(char *dst, unsigned long val, int pad) +{ + char *p = dst + max(pad, (int)__fls(val | 1) / 4 + 1); + + for (*p-- = '\0'; p >= dst; val >>= 4) + *p-- = hex_asc[val & 0x0f]; + return dst; +} + +#define MAX_NUMLEN 21 +static char *as_dec(char *buf, unsigned long val, bool is_signed) +{ + bool negative = false; + char *p = buf + MAX_NUMLEN; + + if (is_signed && (long)val < 0) { + val = (val == LONG_MIN ? LONG_MIN : -(long)val); + negative = true; + } + + *--p = '\0'; + do { + *--p = '0' + (val % 10); + val /= 10; + } while (val); + + if (negative) + *--p = '-'; + return p; +} + +static ssize_t strpad(char *dst, size_t dst_size, const char *src, + int _pad, bool zero_pad, bool decimal) +{ + ssize_t len = strlen(src), pad = _pad; + char *p = dst; + + if (max(len, abs(pad)) >= dst_size) + return -E2BIG; + + if (pad > len) { + if (decimal && zero_pad && *src == '-') { + *p++ = '-'; + src++; + len--; + pad--; + } + memset(p, zero_pad ? '0' : ' ', pad - len); + p += pad - len; + } + memcpy(p, src, len); + p += len; + if (pad < 0 && -pad > len) { + memset(p, ' ', -pad - len); + p += -pad - len; + } + *p = '\0'; + return p - dst; +} + +static char *symstart(char *p) +{ + while (*p) + p--; + return p + 1; +} + +static noinline char *findsym(unsigned long ip, unsigned short *off, unsigned short *len) +{ + /* symbol entries are in a form "10000 c4 startup\0" */ + char *a = _decompressor_syms_start; + char *b = _decompressor_syms_end; + unsigned long start; + unsigned long size; + char *pivot; + char *endp; + + while (a < b) { + pivot = symstart(a + (b - a) / 2); + start = simple_strtoull(pivot, &endp, 16); + size = simple_strtoull(endp + 1, &endp, 16); + if (ip < start) { + b = pivot; + continue; + } + if (ip > start + size) { + a = pivot + strlen(pivot) + 1; + continue; + } + *off = ip - start; + *len = size; + return endp + 1; + } + return NULL; +} + +#define MAX_SYMLEN 64 +static noinline char *strsym(char *buf, void *ip) +{ + unsigned short off; + unsigned short len; + char *p; + + p = findsym((unsigned long)ip, &off, &len); + if (p) { + strncpy(buf, p, MAX_SYMLEN); + /* reserve 15 bytes for offset/len in symbol+0x1234/0x1234 */ + p = buf + strnlen(buf, MAX_SYMLEN - 15); + strcpy(p, "+0x"); + as_hex(p + 3, off, 0); + strcat(p, "/0x"); + as_hex(p + strlen(p), len, 0); + } else { + as_hex(buf, (unsigned long)ip, 16); + } + return buf; +} + +static inline int printk_loglevel(const char *buf) +{ + if (buf[0] == KERN_SOH_ASCII && buf[1]) { + switch (buf[1]) { + case '0' ... '7': + return buf[1] - '0'; + } + } + return MESSAGE_LOGLEVEL_DEFAULT; +} + +static void boot_console_earlyprintk(const char *buf) +{ + int level = printk_loglevel(buf); + + /* always print emergency messages */ + if (level > LOGLEVEL_EMERG && !boot_earlyprintk) + return; + buf = printk_skip_level(buf); + /* print debug messages only when bootdebug is enabled */ + if (level == LOGLEVEL_DEBUG && (!bootdebug || !bootdebug_filter_match(skip_timestamp(buf)))) + return; + if (boot_ignore_loglevel || level < boot_console_loglevel) + sclp_early_printk(buf); +} + +static char *add_timestamp(char *buf) +{ +#ifdef CONFIG_PRINTK_TIME + unsigned long ns = tod_to_ns(__get_tod_clock_monotonic()); + char ts[MAX_NUMLEN]; + + *buf++ = '['; + buf += strpad(buf, MAX_NUMLEN, as_dec(ts, ns / NSEC_PER_SEC, 0), 5, 0, 0); + *buf++ = '.'; + buf += strpad(buf, MAX_NUMLEN, as_dec(ts, (ns % NSEC_PER_SEC) / NSEC_PER_USEC, 0), 6, 1, 0); + *buf++ = ']'; + *buf++ = ' '; +#endif + return buf; +} + +#define va_arg_len_type(args, lenmod, typemod) \ + ((lenmod == 'l') ? va_arg(args, typemod long) : \ + (lenmod == 'h') ? (typemod short)va_arg(args, typemod int) : \ + (lenmod == 'H') ? (typemod char)va_arg(args, typemod int) : \ + (lenmod == 'z') ? va_arg(args, typemod long) : \ + va_arg(args, typemod int)) + +int boot_printk(const char *fmt, ...) +{ + char buf[1024] = { 0 }; + char *end = buf + sizeof(buf) - 1; /* make sure buf is 0 terminated */ + bool zero_pad, decimal; + char *strval, *p = buf; + char valbuf[MAX(MAX_SYMLEN, MAX_NUMLEN)]; + va_list args; + char lenmod; + ssize_t len; + int pad; + + *p++ = KERN_SOH_ASCII; + *p++ = printk_get_level(fmt) ?: '0' + MESSAGE_LOGLEVEL_DEFAULT; + p = add_timestamp(p); + fmt = printk_skip_level(fmt); + + va_start(args, fmt); + for (; p < end && *fmt; fmt++) { + if (*fmt != '%') { + *p++ = *fmt; + continue; + } + if (*++fmt == '%') { + *p++ = '%'; + continue; + } + zero_pad = (*fmt == '0'); + pad = simple_strtol(fmt, (char **)&fmt, 10); + lenmod = (*fmt == 'h' || *fmt == 'l' || *fmt == 'z') ? *fmt++ : 0; + if (lenmod == 'h' && *fmt == 'h') { + lenmod = 'H'; + fmt++; + } + decimal = false; + switch (*fmt) { + case 's': + if (lenmod) + goto out; + strval = va_arg(args, char *); + zero_pad = false; + break; + case 'p': + if (*++fmt != 'S' || lenmod) + goto out; + strval = strsym(valbuf, va_arg(args, void *)); + zero_pad = false; + break; + case 'd': + case 'i': + strval = as_dec(valbuf, va_arg_len_type(args, lenmod, signed), 1); + decimal = true; + break; + case 'u': + strval = as_dec(valbuf, va_arg_len_type(args, lenmod, unsigned), 0); + break; + case 'x': + strval = as_hex(valbuf, va_arg_len_type(args, lenmod, unsigned), 0); + break; + default: + goto out; + } + len = strpad(p, end - p, strval, pad, zero_pad, decimal); + if (len == -E2BIG) + break; + p += len; + } +out: + va_end(args); + len = strlen(buf); + if (len) { + boot_rb_add(buf, len); + boot_console_earlyprintk(buf); + } + return len; +} |