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>
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committed by
Jens Axboe

parent
c761d96b07
commit
dd22f551ac
@@ -139,26 +139,17 @@ axon_ram_make_request(struct request_queue *queue, struct bio *bio)
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* axon_ram_direct_access - direct_access() method for block device
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* @device, @sector, @data: see block_device_operations method
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*/
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static int
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static long
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axon_ram_direct_access(struct block_device *device, sector_t sector,
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void **kaddr, unsigned long *pfn)
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void **kaddr, unsigned long *pfn, long size)
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{
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struct axon_ram_bank *bank = device->bd_disk->private_data;
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loff_t offset;
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offset = sector;
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if (device->bd_part != NULL)
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offset += device->bd_part->start_sect;
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offset <<= AXON_RAM_SECTOR_SHIFT;
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if (offset >= bank->size) {
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dev_err(&bank->device->dev, "Access outside of address space\n");
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return -ERANGE;
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}
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loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT;
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*kaddr = (void *)(bank->ph_addr + offset);
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*pfn = virt_to_phys(kaddr) >> PAGE_SHIFT;
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return 0;
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return bank->size - offset;
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}
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static const struct block_device_operations axon_ram_devops = {
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