path: root/arch/parisc/kernel/firmware.c

/*
 * arch/parisc/kernel/firmware.c  - safe PDC access routines
 *
 *	PDC == Processor Dependent Code
 *
 * See http://www.parisc-linux.org/documentation/index.html
 * for documentation describing the entry points and calling
 * conventions defined below.
 *
 * Copyright 1999 SuSE GmbH Nuernberg (Philipp Rumpf, prumpf@tux.org)
 * Copyright 1999 The Puffin Group, (Alex deVries, David Kennedy)
 * Copyright 2003 Grant Grundler <grundler parisc-linux org>
 * Copyright 2003,2004 Ryan Bradetich <rbrad@parisc-linux.org>
 * Copyright 2004 Thibaut VARENE <varenet@parisc-linux.org>
 *
 *    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; either version 2 of the License, or
 *    (at your option) any later version.
 *
 */

/*	I think it would be in everyone's best interest to follow this
 *	guidelines when writing PDC wrappers:
 *
 *	 - the name of the pdc wrapper should match one of the macros
 *	   used for the first two arguments
 *	 - don't use caps for random parts of the name
 *	 - use the static PDC result buffers and "copyout" to structs
 *	   supplied by the caller to encapsulate alignment restrictions
 *	 - hold pdc_lock while in PDC or using static result buffers
 *	 - use __pa() to convert virtual (kernel) pointers to physical
 *	   ones.
 *	 - the name of the struct used for pdc return values should equal
 *	   one of the macros used for the first two arguments to the
 *	   corresponding PDC call
 *	 - keep the order of arguments
 *	 - don't be smart (setting trailing NUL bytes for strings, return
 *	   something useful even if the call failed) unless you are sure
 *	   it's not going to affect functionality or performance
 *
 *	Example:
 *	int pdc_cache_info(struct pdc_cache_info *cache_info )
 *	{
 *		int retval;
 *
 *		spin_lock_irq(&pdc_lock);
 *		retval = mem_pdc_call(PDC_CACHE,PDC_CACHE_INFO,__pa(cache_info),0);
 *		convert_to_wide(pdc_result);
 *		memcpy(cache_info, pdc_result, sizeof(*cache_info));
 *		spin_unlock_irq(&pdc_lock);
 *
 *		return retval;
 *	}
 *					prumpf	991016	
 */

#include <stdarg.h>

#include <linux/delay.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/spinlock.h>

#include <asm/page.h>
#include <asm/pdc.h>
#include <asm/pdcpat.h>
#include <asm/system.h>
#include <asm/processor.h>	/* for boot_cpu_data */

static DEFINE_SPINLOCK(pdc_lock);
static unsigned long pdc_result[32] __attribute__ ((aligned (8)));
static unsigned long pdc_result2[32] __attribute__ ((aligned (8)));

#ifdef __LP64__
#define WIDE_FIRMWARE 0x1
#define NARROW_FIRMWARE 0x2

/* Firmware needs to be initially set to narrow to determine the 
 * actual firmware width. */
int parisc_narrow_firmware = 1;
#endif

/* On most currently-supported platforms, IODC I/O calls are 32-bit calls
 * and MEM_PDC calls are always the same width as the OS.
 * Some PAT boxes may have 64-bit IODC I/O.
 *
 * Ryan Bradetich added the now obsolete CONFIG_PDC_NARROW to allow
 * 64-bit kernels to run on systems with 32-bit MEM_PDC calls.
 * This allowed wide kernels to run on Cxxx boxes.
 * We now detect 32-bit-only PDC and dynamically switch to 32-bit mode
 * when running a 64-bit kernel on such boxes (e.g. C200 or C360).
 */

#ifdef __LP64__
long real64_call(unsigned long function, ...);
#endif
long real32_call(unsigned long function, ...);

#ifdef __LP64__