block: Change direct_access calling convention
In order to support accesses to larger chunks of memory, pass in a
'size' parameter (counted in bytes), and return the amount available at
that address.
Add a new helper function, bdev_direct_access(), to handle common
functionality including partition handling, checking the length requested
is positive, checking for the sector being page-aligned, and checking
the length of the request does not pass the end of the partition.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/arch/powerpc/sysdev/axonram.c b/arch/powerpc/sysdev/axonram.c
index f532c92..20f8afe 100644
--- a/arch/powerpc/sysdev/axonram.c
+++ b/arch/powerpc/sysdev/axonram.c
@@ -139,26 +139,17 @@
* axon_ram_direct_access - direct_access() method for block device
* @device, @sector, @data: see block_device_operations method
*/
-static int
+static long
axon_ram_direct_access(struct block_device *device, sector_t sector,
- void **kaddr, unsigned long *pfn)
+ void **kaddr, unsigned long *pfn, long size)
{
struct axon_ram_bank *bank = device->bd_disk->private_data;
- loff_t offset;
-
- offset = sector;
- if (device->bd_part != NULL)
- offset += device->bd_part->start_sect;
- offset <<= AXON_RAM_SECTOR_SHIFT;
- if (offset >= bank->size) {
- dev_err(&bank->device->dev, "Access outside of address space\n");
- return -ERANGE;
- }
+ loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT;
*kaddr = (void *)(bank->ph_addr + offset);
*pfn = virt_to_phys(kaddr) >> PAGE_SHIFT;
- return 0;
+ return bank->size - offset;
}
static const struct block_device_operations axon_ram_devops = {