diff options
| -rw-r--r-- | sys/include/vm/vm_page.h | 37 | ||||
| -rw-r--r-- | sys/vm/vm_page.c | 73 |
2 files changed, 110 insertions, 0 deletions
diff --git a/sys/include/vm/vm_page.h b/sys/include/vm/vm_page.h new file mode 100644 index 0000000..704e116 --- /dev/null +++ b/sys/include/vm/vm_page.h @@ -0,0 +1,37 @@ +/* + * Copyright (c) 2023 Ian Marco Moffett and the VegaOS 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 VegaOS 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 <sys/types.h> + +void vm_zero_page(void *page, size_t page_count); + +#endif /* !_VM_PAGE_H_ */ diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c new file mode 100644 index 0000000..d344f4b --- /dev/null +++ b/sys/vm/vm_page.c @@ -0,0 +1,73 @@ +/* + * Copyright (c) 2023 Ian Marco Moffett and the VegaOS 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 VegaOS 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. + */ + +#include <sys/cdefs.h> +#include <sys/panic.h> +#include <vm/vm_page.h> +#include <vm/vm.h> +#include <string.h> + +__MODULE_NAME("vm_page"); +__KERNEL_META("$Vega$: vm_page.c, Ian Marco Moffett, " + "Virtual memory page specific operations"); + +/* + * Zero `page_count' pages. + * + * @page: First page to start zeroing at + * @page_count: Number of pages to zero. + */ +void +vm_zero_page(void *page, size_t page_count) +{ + const size_t PAGE_SIZE = vm_get_page_size(); + size_t bytes = page_count * PAGE_SIZE; + + /* + * This *should not* happen. Page sizes + * are usually 2^n but if this runs, something + * *very* weird is happening and either something + * broke badly. Or it's that damn technological + * degeneration that is getting out of hand within + * our world!! But really, page sizes *should* be a + * power of 2 and it would be pretty worrying if + * this branches causing a panic stating something + * that shouldn't happen, happened. + * + * The reason why it is wise for pages to be a power of + * 2 is so we can efficiently read/write to the page in + * fixed-sized power of 2 blocks cleanly without the risk + * of clobbering other pages we didn't intend to mess with. + */ + if ((PAGE_SIZE & 1) != 0) { + panic("Unexpected page size, not power of 2!\n"); + } + + memset64(page, 0, bytes/8); +} |