1 #include <linux/init.h>
2 #include <linux/mm.h>
3
4 #include <asm/mtrr.h>
5 #include <asm/msr.h>
6
7 #include "mtrr.h"
8
9 static struct {
10 unsigned long high;
11 unsigned long low;
12 } centaur_mcr[8];
13
14 static u8 centaur_mcr_reserved;
15 static u8 centaur_mcr_type; /* 0 for winchip, 1 for winchip2 */
16
17 /**
18 * centaur_get_free_region - Get a free MTRR.
19 *
20 * @base: The starting (base) address of the region.
21 * @size: The size (in bytes) of the region.
22 *
23 * Returns: the index of the region on success, else -1 on error.
24 */
25 static int
centaur_get_free_region(unsigned long base,unsigned long size,int replace_reg)26 centaur_get_free_region(unsigned long base, unsigned long size, int replace_reg)
27 {
28 unsigned long lbase, lsize;
29 mtrr_type ltype;
30 int i, max;
31
32 max = num_var_ranges;
33 if (replace_reg >= 0 && replace_reg < max)
34 return replace_reg;
35
36 for (i = 0; i < max; ++i) {
37 if (centaur_mcr_reserved & (1 << i))
38 continue;
39 mtrr_if->get(i, &lbase, &lsize, <ype);
40 if (lsize == 0)
41 return i;
42 }
43
44 return -ENOSPC;
45 }
46
47 /*
48 * Report boot time MCR setups
49 */
mtrr_centaur_report_mcr(int mcr,u32 lo,u32 hi)50 void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi)
51 {
52 centaur_mcr[mcr].low = lo;
53 centaur_mcr[mcr].high = hi;
54 }
55
56 static void
centaur_get_mcr(unsigned int reg,unsigned long * base,unsigned long * size,mtrr_type * type)57 centaur_get_mcr(unsigned int reg, unsigned long *base,
58 unsigned long *size, mtrr_type * type)
59 {
60 *base = centaur_mcr[reg].high >> PAGE_SHIFT;
61 *size = -(centaur_mcr[reg].low & 0xfffff000) >> PAGE_SHIFT;
62 *type = MTRR_TYPE_WRCOMB; /* write-combining */
63
64 if (centaur_mcr_type == 1 && ((centaur_mcr[reg].low & 31) & 2))
65 *type = MTRR_TYPE_UNCACHABLE;
66 if (centaur_mcr_type == 1 && (centaur_mcr[reg].low & 31) == 25)
67 *type = MTRR_TYPE_WRBACK;
68 if (centaur_mcr_type == 0 && (centaur_mcr[reg].low & 31) == 31)
69 *type = MTRR_TYPE_WRBACK;
70 }
71
72 static void
centaur_set_mcr(unsigned int reg,unsigned long base,unsigned long size,mtrr_type type)73 centaur_set_mcr(unsigned int reg, unsigned long base,
74 unsigned long size, mtrr_type type)
75 {
76 unsigned long low, high;
77
78 if (size == 0) {
79 /* Disable */
80 high = low = 0;
81 } else {
82 high = base << PAGE_SHIFT;
83 if (centaur_mcr_type == 0) {
84 /* Only support write-combining... */
85 low = -size << PAGE_SHIFT | 0x1f;
86 } else {
87 if (type == MTRR_TYPE_UNCACHABLE)
88 low = -size << PAGE_SHIFT | 0x02; /* NC */
89 else
90 low = -size << PAGE_SHIFT | 0x09; /* WWO, WC */
91 }
92 }
93 centaur_mcr[reg].high = high;
94 centaur_mcr[reg].low = low;
95 wrmsr(MSR_IDT_MCR0 + reg, low, high);
96 }
97
98 static int
centaur_validate_add_page(unsigned long base,unsigned long size,unsigned int type)99 centaur_validate_add_page(unsigned long base, unsigned long size, unsigned int type)
100 {
101 /*
102 * FIXME: Winchip2 supports uncached
103 */
104 if (type != MTRR_TYPE_WRCOMB &&
105 (centaur_mcr_type == 0 || type != MTRR_TYPE_UNCACHABLE)) {
106 pr_warning("mtrr: only write-combining%s supported\n",
107 centaur_mcr_type ? " and uncacheable are" : " is");
108 return -EINVAL;
109 }
110 return 0;
111 }
112
113 static const struct mtrr_ops centaur_mtrr_ops = {
114 .vendor = X86_VENDOR_CENTAUR,
115 .set = centaur_set_mcr,
116 .get = centaur_get_mcr,
117 .get_free_region = centaur_get_free_region,
118 .validate_add_page = centaur_validate_add_page,
119 .have_wrcomb = positive_have_wrcomb,
120 };
121
centaur_init_mtrr(void)122 int __init centaur_init_mtrr(void)
123 {
124 set_mtrr_ops(¢aur_mtrr_ops);
125 return 0;
126 }
127