forked from Minki/linux
ef1afd4d79
Commit 721fdf3416 introduced a subtle bug
by accidently removing the "static" from iodc_dbuf. This resulted in, what
appeared to be, a trap without *current set to a task. Probably the result of
a trap in real mode while calling firmware.
Also do other misc clean ups. Since the only input from firmware is non
blocking, share iodc_dbuf between input and output, and spinlock the
only callers.
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
160 lines
4.7 KiB
C
160 lines
4.7 KiB
C
/*
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* PDC Console support - ie use firmware to dump text via boot console
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*
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* Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
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* Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
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* Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
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* Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
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* Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
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* Copyright (C) 2000 Michael Ang <mang with subcarrier.org>
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* Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
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* Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
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* Copyright (C) 2001 Helge Deller <deller at parisc-linux.org>
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* Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
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* Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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/*
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* The PDC console is a simple console, which can be used for debugging
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* boot related problems on HP PA-RISC machines.
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*
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* This code uses the ROM (=PDC) based functions to read and write characters
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* from and to PDC's boot path.
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* Since all character read from that path must be polled, this code never
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* can or will be a fully functional linux console.
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*/
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/* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems.
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* On production kernels EARLY_BOOTUP_DEBUG should be undefined. */
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#define EARLY_BOOTUP_DEBUG
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#include <linux/kernel.h>
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#include <linux/console.h>
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#include <linux/string.h>
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#include <linux/init.h>
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#include <linux/major.h>
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#include <linux/tty.h>
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#include <asm/pdc.h> /* for iodc_call() proto and friends */
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static spinlock_t pdc_console_lock = SPIN_LOCK_UNLOCKED;
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static void pdc_console_write(struct console *co, const char *s, unsigned count)
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{
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int i = 0;
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unsigned long flags;
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spin_lock_irqsave(&pdc_console_lock, flags);
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do {
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i += pdc_iodc_print(s + i, count - i);
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} while (i < count);
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spin_unlock_irqrestore(&pdc_console_lock, flags);
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}
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int pdc_console_poll_key(struct console *co)
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{
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int c;
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unsigned long flags;
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spin_lock_irqsave(&pdc_console_lock, flags);
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c = pdc_iodc_getc();
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spin_unlock_irqrestore(&pdc_console_lock, flags);
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return c;
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}
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static int pdc_console_setup(struct console *co, char *options)
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{
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return 0;
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}
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#if defined(CONFIG_PDC_CONSOLE)
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#include <linux/vt_kern.h>
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static struct tty_driver * pdc_console_device (struct console *c, int *index)
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{
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extern struct tty_driver console_driver;
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*index = c->index ? c->index-1 : fg_console;
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return &console_driver;
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}
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#else
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#define pdc_console_device NULL
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#endif
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static struct console pdc_cons = {
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.name = "ttyB",
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.write = pdc_console_write,
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.device = pdc_console_device,
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.setup = pdc_console_setup,
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.flags = CON_BOOT | CON_PRINTBUFFER | CON_ENABLED,
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.index = -1,
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};
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static int pdc_console_initialized;
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static void pdc_console_init_force(void)
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{
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if (pdc_console_initialized)
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return;
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++pdc_console_initialized;
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/* If the console is duplex then copy the COUT parameters to CIN. */
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if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
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memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
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/* register the pdc console */
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register_console(&pdc_cons);
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}
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void __init pdc_console_init(void)
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{
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#if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE)
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pdc_console_init_force();
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#endif
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#ifdef EARLY_BOOTUP_DEBUG
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printk(KERN_INFO "Initialized PDC Console for debugging.\n");
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#endif
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}
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/*
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* Used for emergencies. Currently only used if an HPMC occurs. If an
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* HPMC occurs, it is possible that the current console may not be
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* properly initialised after the PDC IO reset. This routine unregisters
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* all of the current consoles, reinitializes the pdc console and
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* registers it.
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*/
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void pdc_console_restart(void)
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{
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struct console *console;
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if (pdc_console_initialized)
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return;
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/* If we've already seen the output, don't bother to print it again */
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if (console_drivers != NULL)
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pdc_cons.flags &= ~CON_PRINTBUFFER;
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while ((console = console_drivers) != NULL)
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unregister_console(console_drivers);
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/* force registering the pdc console */
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pdc_console_init_force();
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}
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