xref: /openbmc/u-boot/arch/x86/include/asm/mtrr.h (revision 86bedaeb)
1 /*
2  * Copyright (c) 2014 Google, Inc
3  *
4  * From Coreboot file of the same name
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  */
8 
9 #ifndef _ASM_MTRR_H
10 #define _ASM_MTRR_H
11 
12 /* MTRR region types */
13 #define MTRR_TYPE_UNCACHEABLE	0
14 #define MTRR_TYPE_WRCOMB	1
15 #define MTRR_TYPE_WRTHROUGH	4
16 #define MTRR_TYPE_WRPROT	5
17 #define MTRR_TYPE_WRBACK	6
18 
19 #define MTRR_TYPE_COUNT		7
20 
21 #define MTRR_CAP_MSR		0x0fe
22 #define MTRR_DEF_TYPE_MSR	0x2ff
23 
24 #define MTRR_DEF_TYPE_EN	(1 << 11)
25 #define MTRR_DEF_TYPE_FIX_EN	(1 << 10)
26 
27 #define MTRR_PHYS_BASE_MSR(reg)	(0x200 + 2 * (reg))
28 #define MTRR_PHYS_MASK_MSR(reg)	(0x200 + 2 * (reg) + 1)
29 
30 #define MTRR_PHYS_MASK_VALID	(1 << 11)
31 
32 #define MTRR_BASE_TYPE_MASK	0x7
33 
34 /* Number of MTRRs supported */
35 #define MTRR_COUNT		8
36 
37 #if !defined(__ASSEMBLER__)
38 
39 /**
40  * Information about the previous MTRR state, set up by mtrr_open()
41  *
42  * @deftype:		Previous value of MTRR_DEF_TYPE_MSR
43  * @enable_cache:	true if cache was enabled
44  */
45 struct mtrr_state {
46 	uint64_t deftype;
47 	bool enable_cache;
48 };
49 
50 /**
51  * mtrr_open() - Prepare to adjust MTRRs
52  *
53  * Use mtrr_open() passing in a structure - this function will init it. Then
54  * when done, pass the same structure to mtrr_close() to re-enable MTRRs and
55  * possibly the cache.
56  *
57  * @state:	Empty structure to pass in to hold settings
58  */
59 void mtrr_open(struct mtrr_state *state);
60 
61 /**
62  * mtrr_open() - Clean up after adjusting MTRRs, and enable them
63  *
64  * This uses the structure containing information returned from mtrr_open().
65  *
66  * @state:	Structure from mtrr_open()
67  */
68 void mtrr_close(struct mtrr_state *state);
69 
70 /**
71  * mtrr_add_request() - Add a new MTRR request
72  *
73  * This adds a request for a memory region to be set up in a particular way.
74  *
75  * @type:	Requested type (MTRR_TYPE_)
76  * @start:	Start address
77  * @size:	Size
78  *
79  * @return:	0 on success, non-zero on failure
80  */
81 int mtrr_add_request(int type, uint64_t start, uint64_t size);
82 
83 /**
84  * mtrr_commit() - set up the MTRR registers based on current requests
85  *
86  * This sets up MTRRs for the available DRAM and the requests received so far.
87  * It must be called with caches disabled.
88  *
89  * @do_caches:	true if caches are currently on
90  *
91  * @return:	0 on success, non-zero on failure
92  */
93 int mtrr_commit(bool do_caches);
94 
95 #endif
96 
97 #if ((CONFIG_XIP_ROM_SIZE & (CONFIG_XIP_ROM_SIZE - 1)) != 0)
98 # error "CONFIG_XIP_ROM_SIZE is not a power of 2"
99 #endif
100 
101 #if ((CONFIG_CACHE_ROM_SIZE & (CONFIG_CACHE_ROM_SIZE - 1)) != 0)
102 # error "CONFIG_CACHE_ROM_SIZE is not a power of 2"
103 #endif
104 
105 #define CACHE_ROM_BASE	(((1 << 20) - (CONFIG_CACHE_ROM_SIZE >> 12)) << 12)
106 
107 #endif
108