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#include <linux/irqflags.h>
18
19/*
20 * Until we get an assembler that knows about the pvr registers,
21 * this horrible cruft will have to do.
22 * That hardcoded opcode is mfs r3, rpvrNN
23 */
24
25#define get_single_pvr(pvrid, val) \
26{ \
27 register unsigned tmp __asm__("r3"); \
28 tmp = 0x0; /* Prevent warning about unused */ \
29 __asm__ __volatile__ ( \
30 "mfs %0, rpvr" #pvrid ";" \
31 : "=r" (tmp) : : "memory"); \
32 val = tmp; \
33}
34
35/*
36 * Does the CPU support the PVR register?
37 * return value:
38 * 0: no PVR
39 * 1: simple PVR
40 * 2: full PVR
41 *
42 * This must work on all CPU versions, including those before the
43 * PVR was even an option.
44 */
45
46int cpu_has_pvr(void)
47{
48 unsigned long flags;
49 unsigned pvr0;
50
51 local_save_flags(flags);
52
53 /* PVR bit in MSR tells us if there is any support */
54 if (!(flags & PVR_MSR_BIT))
55 return 0;
56
57 get_single_pvr(0, pvr0);
58 pr_debug("%s: pvr0 is 0x%08x\n", __func__, pvr0);
59
60 if (pvr0 & PVR0_PVR_FULL_MASK)
61 return 1;
62
63 /* for partial PVR use static cpuinfo */
64 return 2;
65}
66
67void get_pvr(struct pvr_s *p)
68{
69 get_single_pvr(0, p->pvr[0]);
70 get_single_pvr(1, p->pvr[1]);
71 get_single_pvr(2, p->pvr[2]);
72 get_single_pvr(3, p->pvr[3]);
73 get_single_pvr(4, p->pvr[4]);
74 get_single_pvr(5, p->pvr[5]);
75 get_single_pvr(6, p->pvr[6]);
76 get_single_pvr(7, p->pvr[7]);
77 get_single_pvr(8, p->pvr[8]);
78 get_single_pvr(9, p->pvr[9]);
79 get_single_pvr(10, p->pvr[10]);
80 get_single_pvr(11, p->pvr[11]);
81}
82

source code of linux/arch/microblaze/kernel/cpu/pvr.c