iowrite32() problem

Hello, I’m programming a loadable kernel module to access the gpio’s.
But I 've problems when i tried to insert the module and specifically when I use the
“iowrite32 ( )” function. But when I use the “ioread32 ()” function, I don’t have any problems.

My module name is “gpio_conf.ko” and the kernel messages that i receive when I try to insert the module are:

[ 1986.699981] gpio_conf: disagrees about version of symbol outer_cache
[ 1986.700042] gpio_conf: Unknown symbol outer_cache (err -22)

It is possible that i have to load other module previosly to use iowrite32 () function ?

My system is: Ubuntu 11.10
Linux-omap 3.2.7-x5
beagleBoard xm

Thanks