a0ebddaac1
This implements the file system logic for posix shared memory: shm_open, shm_unlink, mmap, munmap and close For flat and protected builds the memory simply allocated from (user) heap For kernel build the memory is allocated from page pool and mapped with MMU This doesn't yet support protection flags or re-sizing already truncated shared memory area. Co-authored-by: Ville Juven <ville.juven@unikie.com> Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>
144 lines
3.6 KiB
C
144 lines
3.6 KiB
C
/****************************************************************************
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* fs/shm/shmfs_alloc.c
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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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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <stdbool.h>
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#include <nuttx/kmalloc.h>
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#include <nuttx/pgalloc.h>
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#include "shm/shmfs.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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FAR struct shmfs_object_s *shmfs_alloc_object(size_t length)
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{
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FAR struct shmfs_object_s *object;
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bool allocated = false;
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#if defined(CONFIG_BUILD_FLAT)
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/* in FLAT build, allocate the object metadata and the data in the same
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* chunk in kernel heap
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*/
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object = kmm_zalloc(sizeof(struct shmfs_object_s) + length);
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if (object)
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{
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object->paddr = (FAR char *)object + sizeof(struct shmfs_object_s);
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allocated = true;
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}
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#elif defined(CONFIG_BUILD_PROTECTED)
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/* in PROTECTED build, allocate the shm object in kernel heap, and shared
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* memory in user heap
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*/
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object = kmm_zalloc(sizeof(struct shmfs_object_s));
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if (object)
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{
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object->paddr = kumm_zalloc(length);
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if (object->paddr)
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{
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allocated = true;
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}
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}
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#elif defined(CONFIG_BUILD_KERNEL)
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/* in KERNEL build, allocate the shared memory from page pool and store the
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* physical address
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*/
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size_t i = 0;
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FAR void **pages;
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size_t n_pages = MM_NPAGES(length);
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object = kmm_zalloc(sizeof(struct shmfs_object_s) +
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(n_pages - 1) * sizeof(object->paddr));
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if (object)
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{
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pages = &object->paddr;
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for (; i < n_pages; i++)
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{
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pages[i] = (FAR void *)mm_pgalloc(1);
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if (!pages[i])
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{
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break;
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}
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}
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}
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if (i == n_pages)
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{
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allocated = true;
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}
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#endif
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if (allocated)
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{
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object->length = length;
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}
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else
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{
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/* delete any partial allocation */
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shmfs_free_object(object);
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object = NULL;
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}
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return object;
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}
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void shmfs_free_object(FAR struct shmfs_object_s *object)
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{
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#if defined(CONFIG_BUILD_KERNEL)
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size_t i;
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size_t n_pages = MM_NPAGES(object->length);
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FAR void **pages;
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#endif
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if (object)
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{
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#if defined (CONFIG_BUILD_PROTECTED)
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kumm_free(object->paddr);
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#elif defined(CONFIG_BUILD_KERNEL)
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pages = &object->paddr;
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for (i = 0; i < n_pages; i++)
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{
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if (pages[i])
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{
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mm_pgfree((uintptr_t)pages[i], 1);
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}
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}
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#endif
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/* Delete the object metadata
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* (and the shared memory in case of FLAT build)
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*/
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kmm_free(object);
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}
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}
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