linux_dsm_epyc7002/arch/tile/kernel/early_printk.c
Chris Metcalf bda0f5bad8 tile: various console improvements
This change improves and cleans up the tile console.

- We enable HVC_IRQ support on tilegx, with the addition of a new
  Tilera hypervisor API for tilegx to allow a console IPI.  If IPI
  support is not available we fall back to the previous polling mode.

- We simplify the earlyprintk code to use CON_BOOT and eliminate some
  of the other supporting earlyprintk code.

- A new tile_console_write() primitive is used to send output to
  the console and is factored out of the hvc_tile driver.
  This lets us support a "sim_console" boot argument to allow using
  simulator hooks to send output to the "console" as a slightly
  faster alternative to emulating the hardware more directly.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12 14:46:18 -04:00

69 lines
1.7 KiB
C

/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#include <linux/console.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/irqflags.h>
#include <linux/printk.h>
#include <asm/setup.h>
#include <hv/hypervisor.h>
static void early_hv_write(struct console *con, const char *s, unsigned n)
{
tile_console_write(s, n);
/*
* Convert NL to NLCR (close enough to CRNL) during early boot.
* We assume newlines are at the ends of strings, which turns out
* to be good enough for early boot console output.
*/
if (n && s[n-1] == '\n')
tile_console_write("\r", 1);
}
static struct console early_hv_console = {
.name = "earlyhv",
.write = early_hv_write,
.flags = CON_PRINTBUFFER | CON_BOOT,
.index = -1,
};
void early_panic(const char *fmt, ...)
{
va_list ap;
arch_local_irq_disable_all();
va_start(ap, fmt);
early_printk("Kernel panic - not syncing: ");
early_vprintk(fmt, ap);
early_printk("\n");
va_end(ap);
dump_stack();
hv_halt();
}
static int __init setup_early_printk(char *str)
{
if (early_console)
return 1;
early_console = &early_hv_console;
register_console(early_console);
return 0;
}
early_param("earlyprintk", setup_early_printk);