1 /* 2 * Copyright (C) 2014 Imagination Technologies 3 * Author: Paul Burton <paul.burton@imgtec.com> 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License as published by the 7 * Free Software Foundation; either version 2 of the License, or (at your 8 * option) any later version. 9 */ 10 11 #ifndef __MIPS_ASM_MIPS_MAAR_H__ 12 #define __MIPS_ASM_MIPS_MAAR_H__ 13 14 #include <asm/hazards.h> 15 #include <asm/mipsregs.h> 16 17 /** 18 * platform_maar_init() - perform platform-level MAAR configuration 19 * @num_pairs: The number of MAAR pairs present in the system. 20 * 21 * Platforms should implement this function such that it configures as many 22 * MAAR pairs as required, from 0 up to the maximum of num_pairs-1, and returns 23 * the number that were used. Any further MAARs will be configured to be 24 * invalid. The default implementation of this function will simply indicate 25 * that it has configured 0 MAAR pairs. 26 * 27 * Return: The number of MAAR pairs configured. 28 */ 29 unsigned __weak platform_maar_init(unsigned num_pairs); 30 31 /** 32 * write_maar_pair() - write to a pair of MAARs 33 * @idx: The index of the pair (ie. use MAARs idx*2 & (idx*2)+1). 34 * @lower: The lowest address that the MAAR pair will affect. Must be 35 * aligned to a 2^16 byte boundary. 36 * @upper: The highest address that the MAAR pair will affect. Must be 37 * aligned to one byte before a 2^16 byte boundary. 38 * @attrs: The accessibility attributes to program, eg. MIPS_MAAR_S. The 39 * MIPS_MAAR_V attribute will automatically be set. 40 * 41 * Program the pair of MAAR registers specified by idx to apply the attributes 42 * specified by attrs to the range of addresses from lower to higher. 43 */ 44 static inline void write_maar_pair(unsigned idx, phys_addr_t lower, 45 phys_addr_t upper, unsigned attrs) 46 { 47 /* Addresses begin at bit 16, but are shifted right 4 bits */ 48 BUG_ON(lower & (0xffff | ~(MIPS_MAAR_ADDR << 4))); 49 BUG_ON(((upper & 0xffff) != 0xffff) 50 || ((upper & ~0xffffull) & ~(MIPS_MAAR_ADDR << 4))); 51 52 /* Automatically set MIPS_MAAR_V */ 53 attrs |= MIPS_MAAR_V; 54 55 /* Write the upper address & attributes (only MIPS_MAAR_V matters) */ 56 write_c0_maari(idx << 1); 57 back_to_back_c0_hazard(); 58 write_c0_maar(((upper >> 4) & MIPS_MAAR_ADDR) | attrs); 59 back_to_back_c0_hazard(); 60 61 /* Write the lower address & attributes */ 62 write_c0_maari((idx << 1) | 0x1); 63 back_to_back_c0_hazard(); 64 write_c0_maar((lower >> 4) | attrs); 65 back_to_back_c0_hazard(); 66 } 67 68 /** 69 * struct maar_config - MAAR configuration data 70 * @lower: The lowest address that the MAAR pair will affect. Must be 71 * aligned to a 2^16 byte boundary. 72 * @upper: The highest address that the MAAR pair will affect. Must be 73 * aligned to one byte before a 2^16 byte boundary. 74 * @attrs: The accessibility attributes to program, eg. MIPS_MAAR_S. The 75 * MIPS_MAAR_V attribute will automatically be set. 76 * 77 * Describes the configuration of a pair of Memory Accessibility Attribute 78 * Registers - applying attributes from attrs to the range of physical 79 * addresses from lower to upper inclusive. 80 */ 81 struct maar_config { 82 phys_addr_t lower; 83 phys_addr_t upper; 84 unsigned attrs; 85 }; 86 87 /** 88 * maar_config() - configure MAARs according to provided data 89 * @cfg: Pointer to an array of struct maar_config. 90 * @num_cfg: The number of structs in the cfg array. 91 * @num_pairs: The number of MAAR pairs present in the system. 92 * 93 * Configures as many MAARs as are present and specified in the cfg 94 * array with the values taken from the cfg array. 95 * 96 * Return: The number of MAAR pairs configured. 97 */ 98 static inline unsigned maar_config(const struct maar_config *cfg, 99 unsigned num_cfg, unsigned num_pairs) 100 { 101 unsigned i; 102 103 for (i = 0; i < min(num_cfg, num_pairs); i++) 104 write_maar_pair(i, cfg[i].lower, cfg[i].upper, cfg[i].attrs); 105 106 return i; 107 } 108 109 #endif /* __MIPS_ASM_MIPS_MAAR_H__ */ 110