/*
 * 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/exceptions.h>
#include <asm/pvr.h>
#include <linux/irqflags.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__ (                                  \
                        "mfs    %0, rpvr" #pvrid ";"            \
                        : "=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 long 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(0, 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]);
}