There are many ways of making walls for this sort of tile.
The two examples you give above use the same technique which you should be able to replicate on photoshop like this:
1. draw the shape of your walls in a temporary block colour. Note the width of your walls in pixels (ie maybe they are 20 pixels wide).
2. texture the wall shape with your wall texture, probably some sort of stone texture. Usually this layer will be the uppermost layer on your image.
3. Use a bevel and emboss filter on your wall layer. For the size of the filter compare with the thickness of your wall - for example if you bevel the wall size 5 pixels and your wall is 20 pixels wide, the central flat bit will be half the width and the beveled edges will each be a quarter of the with in size.
4. If you want a stronger bevel effect then duplicate step 3.
5. Create a shadow layer directly under the walls layer to make the walls stand out. You can do this easily by duplicating the wall layer and changing the wall to a block black colour, blurring it heavily, placing it BELOW the walls layer, then deleting everything that isn't over the floor.