Re: your mail

Matthew Wilcox
2009-01-19T03:08:01Z

On Mon, Jan 19, 2009 at 10:54:02AM +0800, Gao, Yunpeng wrote:
> I have to use 64bit variable in my 2.6.27 kernel NAND driver as below:
> ---------------------------------------------------------------------------
> u64 NAND_capacity;
> unsigned int block_num, block_size;
> ...
> block_num = NAND_capacity / block_size;
> ---------------------------------------------------------------------------
> but it failed when compiling and reports 'undefined reference to `__udivdi3'.

Presumably block_size is a power of two, so you can do:

block_num = NAND_capacity >> block_shift;

--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."