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/*
* 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 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();
}
/**
* maar_init() - initialise MAARs
*
* Performs initialisation of MAARs for the current CPU, making use of the
* platforms implementation of platform_maar_init where necessary and
* duplicating the setup it provides on secondary CPUs.
*/
extern void maar_init(void);
/**
* 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__ */
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