1
2#include <linux/init.h>
3#include <linux/mm.h>
4
5#include <asm/mtrr.h>
6#include <asm/msr.h>
7
8#include "mtrr.h"
9
10static struct {
11 unsigned long high;
12 unsigned long low;
13} centaur_mcr[8];
14
15static u8 centaur_mcr_reserved;
16static u8 centaur_mcr_type;
17
18
19
20
21
22
23
24
25
26static int
27centaur_get_free_region(unsigned long base, unsigned long size, int replace_reg)
28{
29 unsigned long lbase, lsize;
30 mtrr_type ltype;
31 int i, max;
32
33 max = num_var_ranges;
34 if (replace_reg >= 0 && replace_reg < max)
35 return replace_reg;
36
37 for (i = 0; i < max; ++i) {
38 if (centaur_mcr_reserved & (1 << i))
39 continue;
40 mtrr_if->get(i, &lbase, &lsize, <ype);
41 if (lsize == 0)
42 return i;
43 }
44
45 return -ENOSPC;
46}
47
48
49
50
51void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi)
52{
53 centaur_mcr[mcr].low = lo;
54 centaur_mcr[mcr].high = hi;
55}
56
57static void
58centaur_get_mcr(unsigned int reg, unsigned long *base,
59 unsigned long *size, mtrr_type * type)
60{
61 *base = centaur_mcr[reg].high >> PAGE_SHIFT;
62 *size = -(centaur_mcr[reg].low & 0xfffff000) >> PAGE_SHIFT;
63 *type = MTRR_TYPE_WRCOMB;
64
65 if (centaur_mcr_type == 1 && ((centaur_mcr[reg].low & 31) & 2))
66 *type = MTRR_TYPE_UNCACHABLE;
67 if (centaur_mcr_type == 1 && (centaur_mcr[reg].low & 31) == 25)
68 *type = MTRR_TYPE_WRBACK;
69 if (centaur_mcr_type == 0 && (centaur_mcr[reg].low & 31) == 31)
70 *type = MTRR_TYPE_WRBACK;
71}
72
73static void
74centaur_set_mcr(unsigned int reg, unsigned long base,
75 unsigned long size, mtrr_type type)
76{
77 unsigned long low, high;
78
79 if (size == 0) {
80
81 high = low = 0;
82 } else {
83 high = base << PAGE_SHIFT;
84 if (centaur_mcr_type == 0) {
85
86 low = -size << PAGE_SHIFT | 0x1f;
87 } else {
88 if (type == MTRR_TYPE_UNCACHABLE)
89 low = -size << PAGE_SHIFT | 0x02;
90 else
91 low = -size << PAGE_SHIFT | 0x09;
92 }
93 }
94 centaur_mcr[reg].high = high;
95 centaur_mcr[reg].low = low;
96 wrmsr(MSR_IDT_MCR0 + reg, low, high);
97}
98
99static int
100centaur_validate_add_page(unsigned long base, unsigned long size, unsigned int type)
101{
102
103
104
105 if (type != MTRR_TYPE_WRCOMB &&
106 (centaur_mcr_type == 0 || type != MTRR_TYPE_UNCACHABLE)) {
107 pr_warn("mtrr: only write-combining%s supported\n",
108 centaur_mcr_type ? " and uncacheable are" : " is");
109 return -EINVAL;
110 }
111 return 0;
112}
113
114static const struct mtrr_ops centaur_mtrr_ops = {
115 .vendor = X86_VENDOR_CENTAUR,
116 .set = centaur_set_mcr,
117 .get = centaur_get_mcr,
118 .get_free_region = centaur_get_free_region,
119 .validate_add_page = centaur_validate_add_page,
120 .have_wrcomb = positive_have_wrcomb,
121};
122
123int __init centaur_init_mtrr(void)
124{
125 set_mtrr_ops(¢aur_mtrr_ops);
126 return 0;
127}
128