Damage reduction does not work against spells, as defined in the 3.5 SRD. Ice storm has blungeon damage and cold incase a creature has cold resistance or immunity to make it more versatile.
The kinetic energy to drive the meteor and heat from the explosion are both effects of the Meteor Swarm spell. So those damages are spell damages.
On the other hand, the effect of the Wall of Stone spell is to create a mass of stone instantaneously. Not to let it break and fall. So even if you make a stone mace curved from stones created by a wall of stone spell and strike a werewolf with it, you cannot bypass DR.