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Diffstat (limited to 'arch/mips/include/asm/maar.h')
| -rw-r--r-- | arch/mips/include/asm/maar.h | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/arch/mips/include/asm/maar.h b/arch/mips/include/asm/maar.h new file mode 100644 index 000000000..6c62b0f89 --- /dev/null +++ b/arch/mips/include/asm/maar.h @@ -0,0 +1,109 @@ +/* + * Copyright (C) 2014 Imagination Technologies + * Author: Paul Burton <paul.burton@imgtec.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#ifndef __MIPS_ASM_MIPS_MAAR_H__ +#define __MIPS_ASM_MIPS_MAAR_H__ + +#include <asm/hazards.h> +#include <asm/mipsregs.h> + +/** + * platform_maar_init() - perform platform-level MAAR configuration + * @num_pairs: The number of MAAR pairs present in the system. + * + * Platforms should implement this function such that it configures as many + * MAAR pairs as required, from 0 up to the maximum of num_pairs-1, and returns + * the number that were used. Any further MAARs will be configured to be + * invalid. The default implementation of this function will simply indicate + * that it has configured 0 MAAR pairs. + * + * Return: The number of MAAR pairs configured. + */ +unsigned __weak platform_maar_init(unsigned num_pairs); + +/** + * write_maar_pair() - write to a pair of MAARs + * @idx: The index of the pair (ie. use MAARs idx*2 & (idx*2)+1). + * @lower: The lowest address that the MAAR pair will affect. Must be + * aligned to a 2^16 byte boundary. + * @upper: The highest address that the MAAR pair will affect. Must be + * aligned to one byte before a 2^16 byte boundary. + * @attrs: The accessibility attributes to program, eg. MIPS_MAAR_S. The + * MIPS_MAAR_V attribute will automatically be set. + * + * Program the pair of MAAR registers specified by idx to apply the attributes + * specified by attrs to the range of addresses from lower to higher. + */ +static inline void write_maar_pair(unsigned idx, phys_addr_t lower, + phys_addr_t upper, unsigned attrs) +{ + /* Addresses begin at bit 16, but are shifted right 4 bits */ + BUG_ON(lower & (0xffff | ~(MIPS_MAAR_ADDR << 4))); + BUG_ON(((upper & 0xffff) != 0xffff) + || ((upper & ~0xffffull) & ~(MIPS_MAAR_ADDR << 4))); + + /* Automatically set MIPS_MAAR_V */ + attrs |= MIPS_MAAR_V; + + /* Write the upper address & attributes (only MIPS_MAAR_V matters) */ + write_c0_maari(idx << 1); + back_to_back_c0_hazard(); + write_c0_maar(((upper >> 4) & MIPS_MAAR_ADDR) | attrs); + back_to_back_c0_hazard(); + + /* Write the lower address & attributes */ + write_c0_maari((idx << 1) | 0x1); + back_to_back_c0_hazard(); + write_c0_maar((lower >> 4) | attrs); + back_to_back_c0_hazard(); +} + +/** + * struct maar_config - MAAR configuration data + * @lower: The lowest address that the MAAR pair will affect. Must be + * aligned to a 2^16 byte boundary. + * @upper: The highest address that the MAAR pair will affect. Must be + * aligned to one byte before a 2^16 byte boundary. + * @attrs: The accessibility attributes to program, eg. MIPS_MAAR_S. The + * MIPS_MAAR_V attribute will automatically be set. + * + * Describes the configuration of a pair of Memory Accessibility Attribute + * Registers - applying attributes from attrs to the range of physical + * addresses from lower to upper inclusive. + */ +struct maar_config { + phys_addr_t lower; + phys_addr_t upper; + unsigned attrs; +}; + +/** + * maar_config() - configure MAARs according to provided data + * @cfg: Pointer to an array of struct maar_config. + * @num_cfg: The number of structs in the cfg array. + * @num_pairs: The number of MAAR pairs present in the system. + * + * Configures as many MAARs as are present and specified in the cfg + * array with the values taken from the cfg array. + * + * Return: The number of MAAR pairs configured. + */ +static inline unsigned maar_config(const struct maar_config *cfg, + unsigned num_cfg, unsigned num_pairs) +{ + unsigned i; + + for (i = 0; i < min(num_cfg, num_pairs); i++) + write_maar_pair(i, cfg[i].lower, cfg[i].upper, cfg[i].attrs); + + return i; +} + +#endif /* __MIPS_ASM_MIPS_MAAR_H__ */ |