The patch titled
return pfn from direct_access, for XIP
has been added to the -mm tree. Its filename is
return-pfn-from-direct_access-for-xip.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: return pfn from direct_access, for XIP
From: Jared Hulbert <jaredeh@xxxxxxxxx>
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 <jaredeh@xxxxxxxxx>
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Cc: Carsten Otte <cotte@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/sysdev/axonram.c | 5 +++--
drivers/block/brd.c | 5 +++--
drivers/s390/block/dcssblk.c | 8 +++++---
fs/ext2/xip.c | 24 ++++++++++++++----------
include/linux/fs.h | 3 ++-
5 files changed, 27 insertions(+), 18 deletions(-)
diff -puN arch/powerpc/sysdev/axonram.c~return-pfn-from-direct_access-for-xip arch/powerpc/sysdev/axonram.c
--- a/arch/powerpc/sysdev/axonram.c~return-pfn-from-direct_access-for-xip
+++ a/arch/powerpc/sysdev/axonram.c
@@ -143,7 +143,7 @@ axon_ram_make_request(struct request_que
*/
static int
axon_ram_direct_access(struct block_device *device, sector_t sector,
- unsigned long *data)
+ void **kaddr, unsigned long *pfn)
{
struct axon_ram_bank *bank = device->bd_disk->private_data;
loff_t offset;
@@ -154,7 +154,8 @@ axon_ram_direct_access(struct block_devi
return -ERANGE;
}
- *data = bank->ph_addr + offset;
+ *kaddr = (void *)(bank->ph_addr + offset);
+ *pfn = virt_to_phys(kaddr) >> PAGE_SHIFT;
return 0;
}
diff -puN drivers/block/brd.c~return-pfn-from-direct_access-for-xip drivers/block/brd.c
--- a/drivers/block/brd.c~return-pfn-from-direct_access-for-xip
+++ a/drivers/block/brd.c
@@ -319,7 +319,7 @@ out:
#ifdef CONFIG_BLK_DEV_XIP
static int brd_direct_access (struct block_device *bdev, sector_t sector,
- unsigned long *data)
+ void **kaddr, unsigned long *pfn)
{
struct brd_device *brd = bdev->bd_disk->private_data;
struct page *page;
@@ -333,7 +333,8 @@ static int brd_direct_access (struct blo
page = brd_insert_page(brd, sector);
if (!page)
return -ENOMEM;
- *data = (unsigned long)page_address(page);
+ *kaddr = page_address(page);
+ *pfn = page_to_pfn(page);
return 0;
}
diff -puN drivers/s390/block/dcssblk.c~return-pfn-from-direct_access-for-xip drivers/s390/block/dcssblk.c
--- a/drivers/s390/block/dcssblk.c~return-pfn-from-direct_access-for-xip
+++ a/drivers/s390/block/dcssblk.c
@@ -36,7 +36,7 @@ static int dcssblk_open(struct inode *in
static int dcssblk_release(struct inode *inode, struct file *filp);
static int dcssblk_make_request(struct request_queue *q, struct bio *bio);
static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum,
- unsigned long *data);
+ void **kaddr, unsigned long *pfn);
static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0";
@@ -687,7 +687,7 @@ fail:
static int
dcssblk_direct_access (struct block_device *bdev, sector_t secnum,
- unsigned long *data)
+ void **kaddr, unsigned long *pfn)
{
struct dcssblk_dev_info *dev_info;
unsigned long pgoff;
@@ -700,7 +700,9 @@ dcssblk_direct_access (struct block_devi
pgoff = secnum / (PAGE_SIZE / 512);
if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start)
return -ERANGE;
- *data = (unsigned long) (dev_info->start+pgoff*PAGE_SIZE);
+ *kaddr = (void *) (dev_info->start+pgoff*PAGE_SIZE);
+ *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT;
+
return 0;
}
diff -puN fs/ext2/xip.c~return-pfn-from-direct_access-for-xip fs/ext2/xip.c
--- a/fs/ext2/xip.c~return-pfn-from-direct_access-for-xip
+++ a/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 *
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 *
/* 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);
diff -puN include/linux/fs.h~return-pfn-from-direct_access-for-xip include/linux/fs.h
--- a/include/linux/fs.h~return-pfn-from-direct_access-for-xip
+++ a/include/linux/fs.h
@@ -1177,7 +1177,8 @@ struct block_device_operations {
int (*ioctl) (struct inode *, struct file *, unsigned, unsigned long);
long (*unlocked_ioctl) (struct file *, unsigned, unsigned long);
long (*compat_ioctl) (struct file *, unsigned, unsigned long);
- int (*direct_access) (struct block_device *, sector_t, unsigned long *);
+ int (*direct_access) (struct block_device *, sector_t,
+ void **, unsigned long *);
int (*media_changed) (struct gendisk *);
int (*revalidate_disk) (struct gendisk *);
int (*getgeo)(struct block_device *, struct hd_geometry *);
_
Patches currently in -mm which might be from jaredeh@xxxxxxxxx are
mm-introduce-vm_mixedmap.patch
mm-introduce-pte_special-pte-bit.patch
mm-add-vm_insert_mixed.patch
return-pfn-from-direct_access-for-xip.patch
xip-support-non-struct-page-backed-memory.patch
s390-implement-pte-special-bit.patch
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