arch/microblaze/kernel/cpu/pvr.c

/*
 * Support for MicroBlaze PVR (processor version register)
 *
 * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2007-2009 PetaLogix
 * Copyright (C) 2007 John Williams <john.williams@petalogix.com>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/kernel.h>
#include <linux/compiler.h>
#include <asm/system.h>
#include <asm/exceptions.h>
#include <asm/pvr.h>

/*
 * Until we get an assembler that knows about the pvr registers,
 * this horrible cruft will have to do.
 * That hardcoded opcode is mfs r3, rpvrNN
 */

#define get_single_pvr(pvrid, val)				\
{								\
	register unsigned tmp __asm__("r3");			\
	tmp = 0x0;	/* Prevent warning about unused */	\
	__asm__ __volatile__ (					\
			".byte 0x94,0x60,0xa0, " #pvrid "\n\t"	\
			: "=r" (tmp) : : "memory"); 		\
	val = tmp;						\
}

/*
 * Does the CPU support the PVR register?
 * return value:
 * 0: no PVR
 * 1: simple PVR
 * 2: full PVR
 *
 * This must work on all CPU versions, including those before the
 * PVR was even an option.
 */

int cpu_has_pvr(void)
{
	unsigned flags;
	unsigned pvr0;

	local_save_flags(flags);

	/* PVR bit in MSR tells us if there is any support */
	if (!(flags & PVR_MSR_BIT))
		return 0;

	get_single_pvr(0x00, pvr0);
	pr_debug("%s: pvr0 is 0x%08x\n", __func__, pvr0);

	if (pvr0 & PVR0_PVR_FULL_MASK)
		return 1;

	/* for partial PVR use static cpuinfo */
	return 2;
}

void get_pvr(struct pvr_s *p)
{
	get_single_pvr(0, p->pvr[0]);
	get_single_pvr(1, p->pvr[1]);
	get_single_pvr(2, p->pvr[2]);
	get_single_pvr(3, p->pvr[3]);
	get_single_pvr(4, p->pvr[4]);
	get_single_pvr(5, p->pvr[5]);
	get_single_pvr(6, p->pvr[6]);
	get_single_pvr(7, p->pvr[7]);
	get_single_pvr(8, p->pvr[8]);
	get_single_pvr(9, p->pvr[9]);
	get_single_pvr(10, p->pvr[10]);
	get_single_pvr(11, p->pvr[11]);
}