1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * Copyright (C) 2014 Imagination Technologies
4 * Author: Paul Burton <paul.burton@mips.com>
5 */
6
7 #ifndef __MIPS_ASM_MIPS_MAAR_H__
8 #define __MIPS_ASM_MIPS_MAAR_H__
9
10 #include <asm/hazards.h>
11 #include <asm/mipsregs.h>
12
13 /**
14 * platform_maar_init() - perform platform-level MAAR configuration
15 * @num_pairs: The number of MAAR pairs present in the system.
16 *
17 * Platforms should implement this function such that it configures as many
18 * MAAR pairs as required, from 0 up to the maximum of num_pairs-1, and returns
19 * the number that were used. Any further MAARs will be configured to be
20 * invalid. The default implementation of this function will simply indicate
21 * that it has configured 0 MAAR pairs.
22 *
23 * Return: The number of MAAR pairs configured.
24 */
25 unsigned platform_maar_init(unsigned num_pairs);
26
27 /**
28 * write_maar_pair() - write to a pair of MAARs
29 * @idx: The index of the pair (ie. use MAARs idx*2 & (idx*2)+1).
30 * @lower: The lowest address that the MAAR pair will affect. Must be
31 * aligned to a 2^16 byte boundary.
32 * @upper: The highest address that the MAAR pair will affect. Must be
33 * aligned to one byte before a 2^16 byte boundary.
34 * @attrs: The accessibility attributes to program, eg. MIPS_MAAR_S. The
35 * MIPS_MAAR_VL/MIPS_MAAR_VH attributes will automatically be set.
36 *
37 * Program the pair of MAAR registers specified by idx to apply the attributes
38 * specified by attrs to the range of addresses from lower to higher.
39 */
40 static inline void write_maar_pair(unsigned idx, phys_addr_t lower,
41 phys_addr_t upper, unsigned attrs)
42 {
43 /* Addresses begin at bit 16, but are shifted right 4 bits */
44 BUG_ON(lower & (0xffff | ~(MIPS_MAAR_ADDR << 4)));
45 BUG_ON(((upper & 0xffff) != 0xffff)
46 || ((upper & ~0xffffull) & ~(MIPS_MAAR_ADDR << 4)));
47
48 /* Automatically set MIPS_MAAR_VL */
49 attrs |= MIPS_MAAR_VL;
50
51 /*
52 * Write the upper address & attributes (both MIPS_MAAR_VL and
53 * MIPS_MAAR_VH matter)
54 */
55 write_c0_maari(idx << 1);
56 back_to_back_c0_hazard();
57 write_c0_maar(((upper >> 4) & MIPS_MAAR_ADDR) | attrs);
58 back_to_back_c0_hazard();
59 #ifdef CONFIG_XPA
60 upper >>= MIPS_MAARX_ADDR_SHIFT;
61 writex_c0_maar(((upper >> 4) & MIPS_MAARX_ADDR) | MIPS_MAARX_VH);
62 back_to_back_c0_hazard();
63 #endif
64
65 /* Write the lower address & attributes */
66 write_c0_maari((idx << 1) | 0x1);
67 back_to_back_c0_hazard();
68 write_c0_maar((lower >> 4) | attrs);
69 back_to_back_c0_hazard();
70 #ifdef CONFIG_XPA
71 lower >>= MIPS_MAARX_ADDR_SHIFT;
72 writex_c0_maar(((lower >> 4) & MIPS_MAARX_ADDR) | MIPS_MAARX_VH);
73 back_to_back_c0_hazard();
74 #endif
75 }
76
77 /**
78 * maar_init() - initialise MAARs
79 *
80 * Performs initialisation of MAARs for the current CPU, making use of the
81 * platforms implementation of platform_maar_init where necessary and
82 * duplicating the setup it provides on secondary CPUs.
83 */
84 extern void maar_init(void);
85
86 /**
87 * struct maar_config - MAAR configuration data
88 * @lower: The lowest address that the MAAR pair will affect. Must be
89 * aligned to a 2^16 byte boundary.
90 * @upper: The highest address that the MAAR pair will affect. Must be
91 * aligned to one byte before a 2^16 byte boundary.
92 * @attrs: The accessibility attributes to program, eg. MIPS_MAAR_S. The
93 * MIPS_MAAR_VL attribute will automatically be set.
94 *
95 * Describes the configuration of a pair of Memory Accessibility Attribute
96 * Registers - applying attributes from attrs to the range of physical
97 * addresses from lower to upper inclusive.
98 */
99 struct maar_config {
100 phys_addr_t lower;
101 phys_addr_t upper;
102 unsigned attrs;
103 };
104
105 /**
106 * maar_config() - configure MAARs according to provided data
107 * @cfg: Pointer to an array of struct maar_config.
108 * @num_cfg: The number of structs in the cfg array.
109 * @num_pairs: The number of MAAR pairs present in the system.
110 *
111 * Configures as many MAARs as are present and specified in the cfg
112 * array with the values taken from the cfg array.
113 *
114 * Return: The number of MAAR pairs configured.
115 */
116 static inline unsigned maar_config(const struct maar_config *cfg,
117 unsigned num_cfg, unsigned num_pairs)
118 {
119 unsigned i;
120
121 for (i = 0; i < min(num_cfg, num_pairs); i++)
122 write_maar_pair(i, cfg[i].lower, cfg[i].upper, cfg[i].attrs);
123
124 return i;
125 }
126
127 #endif /* __MIPS_ASM_MIPS_MAAR_H__ */
128
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