87 lines
1.9 KiB
C++
87 lines
1.9 KiB
C++
/*
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* \brief CPU driver
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* \author Stefan Kalkowski
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* \date 2017-10-06
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*/
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/*
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* Copyright (C) 2017 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 Affero General Public License version 3.
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*/
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#include <base/internal/unmanaged_singleton.h>
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#include <hw/assert.h>
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#include <platform_pd.h>
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#include <kernel/cpu.h>
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#include <kernel/pd.h>
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using Mmu_context = Genode::Cpu::Mmu_context;
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using Asid_allocator = Genode::Bit_allocator<256>;
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Genode::Cpu::Context::Context(bool)
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{
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/*
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* initialize cpu_exception with something that gets ignored in
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* Thread::exception
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*/
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cpu_exception = IRQ_FLAG;
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}
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static Asid_allocator & alloc() {
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return *unmanaged_singleton<Asid_allocator>(); }
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Mmu_context::Mmu_context(addr_t page_table_base)
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{
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Sptbr::Asid::set(sptbr, (Genode::uint8_t)alloc().alloc());
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Sptbr::Ppn::set(sptbr, page_table_base >> 12);
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}
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Mmu_context::~Mmu_context()
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{
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unsigned asid = Sptbr::Asid::get(sptbr);
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Cpu::invalidate_tlb_by_pid(asid);
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alloc().free(asid);
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}
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void Genode::Cpu::switch_to(Mmu_context & context)
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{
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/*
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* The sstatus register defines to which privilege level
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* the machin returns when doing an exception return
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*/
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bool user = Sptbr::Asid::get(context.sptbr);
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Sstatus::access_t v = Sstatus::read();
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Sstatus::Spp::set(v, user ? 0 : 1);
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Sstatus::write(v);
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/* change the translation table when necessary */
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//Sptbr::access_t sptbr = Sptbr::read();
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if (user /*&& sptbr != context.sptbr*/)
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Sptbr::write(context.sptbr);
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}
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void Genode::Cpu::mmu_fault(Context &, Kernel::Thread_fault & f)
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{
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f.addr = Genode::Cpu::Sbadaddr::read();
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f.type = Kernel::Thread_fault::PAGE_MISSING;
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}
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void Genode::Cpu::clear_memory_region(addr_t const addr,
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size_t const size, bool)
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{
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memset((void*)addr, 0, size);
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/* FIXME: is this really necessary? */
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Genode::Cpu::sfence();
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}
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