b0706b7167
The main use case for tlb_reset_dirty is to set the TLB_NOTDIRTY flags in TLB entries to force the slow-path on writes. This is used to mark page ranges containing code which has been translated so it can be invalidated if written to. To do this safely we need to ensure the TLB entries in question for all vCPUs are updated before we attempt to run the code otherwise a race could be introduced. To achieve this we atomically set the flag in tlb_reset_dirty_range and take care when setting it when the TLB entry is filled. On 32 bit systems attempting to emulate 64 bit guests we don't even bother as we might not have the atomic primitives available. MTTCG is disabled in this case and can't be forced on. The copy_tlb_helper function helps keep the atomic semantics in one place to avoid confusion. The dirty helper function is made static as it isn't used outside of cputlb. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net>
30 lines
960 B
C
30 lines
960 B
C
/*
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* Common CPU TLB handling
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*
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* Copyright (c) 2003 Fabrice Bellard
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef CPUTLB_H
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#define CPUTLB_H
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#if !defined(CONFIG_USER_ONLY)
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/* cputlb.c */
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void tlb_protect_code(ram_addr_t ram_addr);
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void tlb_unprotect_code(ram_addr_t ram_addr);
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extern int tlb_flush_count;
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#endif
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#endif
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