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/* $NetBSD: shmem_fs.h,v 1.5 2022/08/20 23:49:31 riastradh Exp $ */
/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Taylor R. Campbell.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _LINUX_SHMEM_FS_H_
#define _LINUX_SHMEM_FS_H_
#include <sys/types.h>
#include <sys/param.h>
#include <sys/rwlock.h>
#include <lib/libkern/libkern.h>
#include <uvm/uvm_extern.h>
#include <uvm/uvm_object.h>
#include <linux/err.h>
#include <linux/gfp.h>
#include <linux/mm_types.h>
static inline struct page *
shmem_read_mapping_page_gfp(struct uvm_object *uobj, voff_t i, gfp_t gfp)
{
struct vm_page *vm_page;
int error;
error = uvm_obj_wirepages(uobj, i*PAGE_SIZE, (i + 1)*PAGE_SIZE, NULL);
if (error)
return ERR_PTR(-error); /* XXX errno NetBSD->Linux */
rw_enter(uobj->vmobjlock, RW_READER);
vm_page = uvm_pagelookup(uobj, i*PAGE_SIZE);
rw_exit(uobj->vmobjlock);
KASSERT(vm_page);
return container_of(vm_page, struct page, p_vmp);
}
static inline struct page *
shmem_read_mapping_page(struct uvm_object *uobj, voff_t i)
{
return shmem_read_mapping_page_gfp(uobj, i, GFP_KERNEL);
}
static inline void
shmem_truncate_range(struct uvm_object *uobj, voff_t start, voff_t end)
{
int flags = PGO_FREE;
if (start == 0 && end == -1) {
flags |= PGO_ALLPAGES;
} else {
KASSERT(0 <= start);
KASSERT(start <= end);
}
rw_enter(uobj->vmobjlock, RW_WRITER);
(*uobj->pgops->pgo_put)(uobj, start, end, flags);
}
#endif /* _LINUX_SHMEM_FS_H_ */
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