0476e30a6d
This adds functionality to map pages dynamically into kernel virtual memory. This allows implementing I/O remap for example, which is a useful (future) feature. Now, the first target is to support mapping user pages for the kernel. Why? There are some userspace structures that might be needed when the userspace process is not running. Semaphores are one such example. Signals and the WDT timeout both need access to the user semaphore to work properly. Even though for this only obtaining the kernel addressable page pool virtual address is needed, for completeness a procedure is provided to map several pages.
33 lines
1.1 KiB
Plaintext
33 lines
1.1 KiB
Plaintext
############################################################################
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# mm/kmap/Make.defs
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#
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# Licensed to the Apache Software Foundation (ASF) under one or more
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# contributor license agreements. See the NOTICE file distributed with
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# this work for additional information regarding copyright ownership. The
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# ASF licenses this file to you under the Apache License, Version 2.0 (the
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# "License"); you may not use this file except in compliance with the
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# License. You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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#
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############################################################################
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ifeq ($(CONFIG_MM_KMAP),y)
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# Kernel virtual mapping support
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CSRCS += kmm_map.c
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# Add the shared memory directory to the build
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DEPPATH += --dep-path kmap
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VPATH += :kmap
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endif
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