From 0bdb884b331c58d33c3ccf29070e2955095a1acc Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sun, 15 Dec 2024 22:57:21 -0500 Subject: kernel: vm: Add objects, page struct and pagers This commit expands the virtual memory subsystem by providing the initial implementation of virtual memory objects, pager descriptors and pagers. This change currently implemenents a minimal vnode pager. Signed-off-by: Ian Moffett --- sys/include/vm/vm_page.h | 65 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 sys/include/vm/vm_page.h (limited to 'sys/include/vm/vm_page.h') diff --git a/sys/include/vm/vm_page.h b/sys/include/vm/vm_page.h new file mode 100644 index 0000000..665431c --- /dev/null +++ b/sys/include/vm/vm_page.h @@ -0,0 +1,65 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * 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. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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 _VM_PAGE_H_ +#define _VM_PAGE_H_ + +#include +#include +#include +#include +#include + +struct vm_object; + +/* + * Represents a single virtual memory page. + */ +struct vm_page { + TAILQ_ENTRY(vm_page) pageq; /* Queue data */ + RBT_ENTRY(vm_page) objt; /* Object tree */ + paddr_t phys_addr; /* Physical address of page */ + struct spinlock lock; /* Page lock */ + uint32_t flags; /* Page flags */ + off_t offset; /* Offset into object */ +}; + +/* Page flags */ +#define PG_VALID BIT(0) /* Has to be set to be valid */ +#define PG_CLEAN BIT(1) /* Page has not be written to */ +#define PG_REQ BIT(2) /* Page has been requested by someone */ + +/* Page alloc flags */ +#define PALLOC_ZERO BIT(0) + +struct vm_page *vm_pagelookup(struct vm_object *obj, off_t off); +struct vm_page *vm_pagealloc(struct vm_object *obj, int flags); +void vm_pagefree(struct vm_object *obj, struct vm_page *pg, int flags); + +#endif /* !_VM_PAGE_H_ */ -- cgit v1.2.3