9da42dde2f
Previously, we did the protection-domain switches without a transitional translation table that contains only global mappings. This was fine as long as the CPU did no speculative memory accesses. However, to enabling branch prediction triggers such accesses. Thus, if we don't want to invalidate predictors on every context switch, we need to switch more carefully. ref #474
83 lines
2.1 KiB
C++
83 lines
2.1 KiB
C++
/**
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* \brief Tools for early translation tables
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* \author Stefan Kalkowski
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* \author Martin Stein
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* \date 2014-08-05
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*/
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/*
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* Copyright (C) 2012-2013 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU General Public License version 2.
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*/
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#ifndef _KERNEL__EARLY_TRANSLATIONS_H_
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#define _KERNEL__EARLY_TRANSLATIONS_H_
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/* core includes */
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#include <page_slab.h>
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#include <translation_table.h>
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namespace Genode
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{
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/**
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* Dummy back-end allocator for early translation tables
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*/
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class Early_translations_allocator;
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/**
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* Aligned slab for early translation tables
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*/
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class Early_translations_slab;
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}
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namespace Kernel
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{
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using Genode::Early_translations_allocator;
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using Genode::Early_translations_slab;
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}
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class Genode::Early_translations_allocator : public Genode::Core_mem_translator
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{
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public:
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Early_translations_allocator() { }
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int add_range(addr_t base, size_t size) { return -1; }
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int remove_range(addr_t base, size_t size) { return -1; }
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Alloc_return alloc_aligned(size_t size, void **out_addr, int align) {
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return Alloc_return::RANGE_CONFLICT; }
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Alloc_return alloc_addr(size_t size, addr_t addr) {
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return Alloc_return::RANGE_CONFLICT; }
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void free(void *addr) {}
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size_t avail() { return 0; }
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bool valid_addr(addr_t addr) { return false; }
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bool alloc(size_t size, void **out_addr) { return false; }
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void free(void *addr, size_t) { }
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size_t overhead(size_t size) { return 0; }
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bool need_size_for_free() const override { return false; }
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void * phys_addr(void * addr) { return addr; }
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void * virt_addr(void * addr) { return addr; }
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};
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class Genode::Early_translations_slab : public Genode::Page_slab
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{
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public:
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typedef Genode::Core_mem_translator Allocator;
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enum {
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ALIGN_LOG2 = Genode::Translation_table::ALIGNM_LOG2,
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ALIGN = 1 << ALIGN_LOG2,
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};
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/**
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* Constructor
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*/
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Early_translations_slab(Allocator * const alloc) : Page_slab(alloc) {
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assert(Genode::aligned(this, ALIGN_LOG2)); }
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} __attribute__((aligned(Early_translations_slab::ALIGN)));
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#endif /* _KERNEL__EARLY_TRANSLATIONS_H_ */
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