diff options
| author | David Howells <dhowells@redhat.com> | 2009-02-12 10:40:00 +0000 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2009-03-24 09:00:19 +0000 |
| commit | 402d326519c1a4859c527702383f4e60f606ef52 (patch) | |
| tree | beb302d56d7671d372ae73f2664feed2a5b1226d /drivers/mtd/mtdchar.c | |
| parent | 9ce969082e490d0a5a81862b364337c93dc3482a (diff) | |
NOMMU: Present backing device capabilities for MTD chardevs
Present backing device capabilities for MTD character device files to allow
NOMMU mmap to do direct mapping where possible.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Bernd Schmidt <bernd.schmidt@analog.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/mtd/mtdchar.c')
| -rw-r--r-- | drivers/mtd/mtdchar.c | 63 |
1 files changed, 62 insertions, 1 deletions
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index 2c8a16f49ca..f478f1fc394 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -13,6 +13,7 @@ #include <linux/slab.h> #include <linux/sched.h> #include <linux/smp_lock.h> +#include <linux/backing-dev.h> #include <linux/mtd/mtd.h> #include <linux/mtd/compatmac.h> @@ -107,12 +108,15 @@ static int mtd_open(struct inode *inode, struct file *file) goto out; } - if (MTD_ABSENT == mtd->type) { + if (mtd->type == MTD_ABSENT) { put_mtd_device(mtd); ret = -ENODEV; goto out; } + if (mtd->backing_dev_info) + file->f_mapping->backing_dev_info = mtd->backing_dev_info; + /* You can't open it RW if it's not a writeable device */ if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) { put_mtd_device(mtd); @@ -781,6 +785,59 @@ static int mtd_ioctl(struct inode *inode, struct file *file, return ret; } /* memory_ioctl */ +/* + * 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) + */ +#ifndef CONFIG_MMU +static unsigned long mtd_get_unmapped_area(struct file *file, + unsigned long addr, + unsigned long len, + unsigned long pgoff, + unsigned long flags) +{ + struct mtd_file_info *mfi = file->private_data; + struct mtd_info *mtd = mfi->mtd; + + if (mtd->get_unmapped_area) { + unsigned long offset; + + if (addr != 0) + return (unsigned long) -EINVAL; + + if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT)) + return (unsigned long) -EINVAL; + + offset = pgoff << PAGE_SHIFT; + if (offset > mtd->size - len) + return (unsigned long) -EINVAL; + + return mtd->get_unmapped_area(mtd, len, offset, flags); + } + + /* can't map directly */ + return (unsigned long) -ENOSYS; +} +#endif + +/* + * set up a mapping for shared memory segments + */ +static int mtd_mmap(struct file *file, struct vm_area_struct *vma) +{ +#ifdef CONFIG_MMU + struct mtd_file_info *mfi = file->private_data; + struct mtd_info *mtd = mfi->mtd; + + if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) + return 0; + return -ENOSYS; +#else + return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS; +#endif +} + static const struct file_operations mtd_fops = { .owner = THIS_MODULE, .llseek = mtd_lseek, @@ -789,6 +846,10 @@ static const struct file_operations mtd_fops = { .ioctl = mtd_ioctl, .open = mtd_open, .release = mtd_close, + .mmap = mtd_mmap, +#ifndef CONFIG_MMU + .get_unmapped_area = mtd_get_unmapped_area, +#endif }; static int __init init_mtdchar(void) |