MIPS: Initialise MAARs (ab9988a3) · Commits · 戴 / test

arch/mips/include/asm/maar.h

0 → 100644

+109 −0

Original line number	Diff line number	Diff line
		/*
		* 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 idx2 & (idx2)+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__ */

arch/mips/mm/init.c

+33 −0

Original line number	Diff line number	Diff line
		@@ -325,6 +325,38 @@ static inline void mem_init_free_highmem(void)
		#endif
		}

		unsigned __weak platform_maar_init(unsigned num_maars)
		{
		return 0;
		}

		static void maar_init(void)
		{
		unsigned num_maars, used, i;

		if (!cpu_has_maar)
		return;

		/* Detect the number of MAARs */
		write_c0_maari(~0);
		back_to_back_c0_hazard();
		num_maars = read_c0_maari() + 1;

		/* MAARs should be in pairs */
		WARN_ON(num_maars % 2);

		/* Configure the required MAARs */
		used = platform_maar_init(num_maars / 2);

		/* Disable any further MAARs */
		for (i = (used * 2); i < num_maars; i++) {
		write_c0_maari(i);
		back_to_back_c0_hazard();
		write_c0_maar(0);
		back_to_back_c0_hazard();
		}
		}

		void __init mem_init(void)
		{
		#ifdef CONFIG_HIGHMEM
		@@ -337,6 +369,7 @@ void __init mem_init(void)
		#endif
		high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);

		maar_init();
		free_all_bootmem();
		setup_zero_pages(); /* Setup zeroed pages. */
		mem_init_free_highmem();

Admin message