From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/fs/romfs/mmap-nommu.c | 89 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 kernel/fs/romfs/mmap-nommu.c (limited to 'kernel/fs/romfs/mmap-nommu.c') diff --git a/kernel/fs/romfs/mmap-nommu.c b/kernel/fs/romfs/mmap-nommu.c new file mode 100644 index 000000000..1118a0dc6 --- /dev/null +++ b/kernel/fs/romfs/mmap-nommu.c @@ -0,0 +1,89 @@ +/* NOMMU mmap support for RomFS on MTD devices + * + * Copyright © 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include +#include "internal.h" + +/* + * try to determine where a shared mapping can be made + * - only supported for NOMMU at the moment (MMU can't doesn't copy private + * mappings) + * - attempts to map through to the underlying MTD device + */ +static unsigned long romfs_get_unmapped_area(struct file *file, + unsigned long addr, + unsigned long len, + unsigned long pgoff, + unsigned long flags) +{ + struct inode *inode = file->f_mapping->host; + struct mtd_info *mtd = inode->i_sb->s_mtd; + unsigned long isize, offset, maxpages, lpages; + int ret; + + if (!mtd) + return (unsigned long) -ENOSYS; + + /* the mapping mustn't extend beyond the EOF */ + lpages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; + isize = i_size_read(inode); + offset = pgoff << PAGE_SHIFT; + + maxpages = (isize + PAGE_SIZE - 1) >> PAGE_SHIFT; + if ((pgoff >= maxpages) || (maxpages - pgoff < lpages)) + return (unsigned long) -EINVAL; + + if (addr != 0) + return (unsigned long) -EINVAL; + + if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT)) + return (unsigned long) -EINVAL; + + offset += ROMFS_I(inode)->i_dataoffset; + if (offset >= mtd->size) + return (unsigned long) -EINVAL; + /* the mapping mustn't extend beyond the EOF */ + if ((offset + len) > mtd->size) + len = mtd->size - offset; + + ret = mtd_get_unmapped_area(mtd, len, offset, flags); + if (ret == -EOPNOTSUPP) + ret = -ENOSYS; + return (unsigned long) ret; +} + +/* + * permit a R/O mapping to be made directly through onto an MTD device if + * possible + */ +static int romfs_mmap(struct file *file, struct vm_area_struct *vma) +{ + return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -ENOSYS; +} + +static unsigned romfs_mmap_capabilities(struct file *file) +{ + struct mtd_info *mtd = file_inode(file)->i_sb->s_mtd; + + if (!mtd) + return NOMMU_MAP_COPY; + return mtd_mmap_capabilities(mtd); +} + +const struct file_operations romfs_ro_fops = { + .llseek = generic_file_llseek, + .read_iter = generic_file_read_iter, + .splice_read = generic_file_splice_read, + .mmap = romfs_mmap, + .get_unmapped_area = romfs_get_unmapped_area, + .mmap_capabilities = romfs_mmap_capabilities, +}; -- cgit 1.2.3-korg