1/*
2 * Support for MicroBlaze PVR (processor version register)
3 *
4 * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
5 * Copyright (C) 2007-2009 PetaLogix
6 * Copyright (C) 2007 John Williams <john.williams@petalogix.com>
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12
13#include <linux/kernel.h>
14#include <linux/compiler.h>
15#include <asm/exceptions.h>
16#include <asm/pvr.h>
17
18/*
19 * Until we get an assembler that knows about the pvr registers,
20 * this horrible cruft will have to do.
21 * That hardcoded opcode is mfs r3, rpvrNN
22 */
23
24#define get_single_pvr(pvrid, val)				\
25{								\
26	register unsigned tmp __asm__("r3");			\
27	tmp = 0x0;	/* Prevent warning about unused */	\
28	__asm__ __volatile__ (					\
29			"mfs	%0, rpvr" #pvrid ";"		\
30			: "=r" (tmp) : : "memory");		\
31	val = tmp;						\
32}
33
34/*
35 * Does the CPU support the PVR register?
36 * return value:
37 * 0: no PVR
38 * 1: simple PVR
39 * 2: full PVR
40 *
41 * This must work on all CPU versions, including those before the
42 * PVR was even an option.
43 */
44
45int cpu_has_pvr(void)
46{
47	unsigned long flags;
48	unsigned pvr0;
49
50	local_save_flags(flags);
51
52	/* PVR bit in MSR tells us if there is any support */
53	if (!(flags & PVR_MSR_BIT))
54		return 0;
55
56	get_single_pvr(0, pvr0);
57	pr_debug("%s: pvr0 is 0x%08x\n", __func__, pvr0);
58
59	if (pvr0 & PVR0_PVR_FULL_MASK)
60		return 1;
61
62	/* for partial PVR use static cpuinfo */
63	return 2;
64}
65
66void get_pvr(struct pvr_s *p)
67{
68	get_single_pvr(0, p->pvr[0]);
69	get_single_pvr(1, p->pvr[1]);
70	get_single_pvr(2, p->pvr[2]);
71	get_single_pvr(3, p->pvr[3]);
72	get_single_pvr(4, p->pvr[4]);
73	get_single_pvr(5, p->pvr[5]);
74	get_single_pvr(6, p->pvr[6]);
75	get_single_pvr(7, p->pvr[7]);
76	get_single_pvr(8, p->pvr[8]);
77	get_single_pvr(9, p->pvr[9]);
78	get_single_pvr(10, p->pvr[10]);
79	get_single_pvr(11, p->pvr[11]);
80}
81