From 30afcb4bd2762fa4b87b17ada9500aa46dc10b1b Mon Sep 17 00:00:00 2001 From: Jared Hulbert Date: Mon, 28 Apr 2008 02:13:02 -0700 Subject: return pfn from direct_access, for XIP Alter the block device ->direct_access() API to work with the new get_xip_mem() API (that requires both kaddr and pfn are returned). Some architectures will not do the right thing in their virt_to_page() for use by XIP (to translate from the kernel virtual address returned by direct_access(), to a user mappable pfn in XIP's page fault handler. However, we can't switch it to just return the pfn and not the kaddr, because we have no good way to get a kva from a pfn, and XIP requires the kva for its read(2) and write(2) handlers. So we have to return both. Signed-off-by: Jared Hulbert Signed-off-by: Nick Piggin Cc: Carsten Otte Cc: Heiko Carstens Cc: linux-mm@kvack.org Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ext2/xip.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) (limited to 'fs/ext2') diff --git a/fs/ext2/xip.c b/fs/ext2/xip.c index ca7f0031238..430b4c8ee97 100644 --- a/fs/ext2/xip.c +++ b/fs/ext2/xip.c @@ -16,11 +16,13 @@ static inline int __inode_direct_access(struct inode *inode, sector_t sector, - unsigned long *data) + void **kaddr, unsigned long *pfn) { - BUG_ON(!inode->i_sb->s_bdev->bd_disk->fops->direct_access); - return inode->i_sb->s_bdev->bd_disk->fops - ->direct_access(inode->i_sb->s_bdev,sector,data); + struct block_device *bdev = inode->i_sb->s_bdev; + struct block_device_operations *ops = bdev->bd_disk->fops; + + BUG_ON(!ops->direct_access); + return ops->direct_access(bdev, sector, kaddr, pfn); } static inline int @@ -48,12 +50,13 @@ int ext2_clear_xip_target(struct inode *inode, int block) { sector_t sector = block * (PAGE_SIZE/512); - unsigned long data; + void *kaddr; + unsigned long pfn; int rc; - rc = __inode_direct_access(inode, sector, &data); + rc = __inode_direct_access(inode, sector, &kaddr, &pfn); if (!rc) - clear_page((void*)data); + clear_page(kaddr); return rc; } @@ -74,7 +77,8 @@ ext2_get_xip_page(struct address_space *mapping, sector_t offset, int create) { int rc; - unsigned long data; + void *kaddr; + unsigned long pfn; sector_t sector; /* first, retrieve the sector number */ @@ -84,9 +88,9 @@ ext2_get_xip_page(struct address_space *mapping, sector_t offset, /* retrieve address of the target data */ rc = __inode_direct_access - (mapping->host, sector * (PAGE_SIZE/512), &data); + (mapping->host, sector * (PAGE_SIZE/512), &kaddr, &pfn); if (!rc) - return virt_to_page(data); + return pfn_to_page(pfn); error: return ERR_PTR(rc); -- cgit v1.2.3