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  */
write_maar_pair(unsigned idx,phys_addr_t lower,phys_addr_t upper,unsigned attrs)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  */
maar_config(const struct maar_config * cfg,unsigned num_cfg,unsigned num_pairs)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