linux/arch/sparc/prom/printf.c
David S. Miller bd4352cadf sparc64: Fix bootup with mcount in some configs.
Functions invoked early when booting up a cpu can't use
tracing because mcount requires a valid 'current_thread_info()'
and TLB mappings to be setup.

The code path of sun4v_register_mondo_queues --> register_one_mondo
is one such case.  sun4v_register_mondo_queues already has the
necessary 'notrace' annotation, but register_one_mondo does not.

Normally register_one_mondo is inlined so the bug doesn't trigger,
but with some config/compiler combinations, it won't be so we
must properly mark it notrace.

While we're here, add 'notrace' annoations to prom_printf and
prom_halt so that early error handling won't have the same problem.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Reported-by: Leif Sawyer <lsawyer@gci.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-04 03:39:45 -07:00

46 lines
1.1 KiB
C

/*
* printf.c: Internal prom library printf facility.
*
* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
* Copyright (c) 2002 Pete Zaitcev (zaitcev@yahoo.com)
*
* We used to warn all over the code: DO NOT USE prom_printf(),
* and yet people do. Anton's banking code was outputting banks
* with prom_printf for most of the 2.4 lifetime. Since an effective
* stick is not available, we deployed a carrot: an early printk
* through PROM by means of -p boot option. This ought to fix it.
* USE printk; if you need, deploy -p.
*/
#include <linux/kernel.h>
#include <linux/compiler.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
static char ppbuf[1024];
void notrace prom_write(const char *buf, unsigned int n)
{
char ch;
while (n != 0) {
--n;
if ((ch = *buf++) == '\n')
prom_putchar('\r');
prom_putchar(ch);
}
}
void notrace prom_printf(const char *fmt, ...)
{
va_list args;
int i;
va_start(args, fmt);
i = vscnprintf(ppbuf, sizeof(ppbuf), fmt, args);
va_end(args);
prom_write(ppbuf, i);
}