Grab a brush and enter quick mask mode, paint a selection around the edges of the area you want to work on, softness of your brush will depend on the edges in the image, extend the painting beyond where you will be wanting to clone into, but stick to edges within the image. Once you are happy with the area defined, exit quick mask, create a new blank layer and with the selection active nit the "Mask" icon which will put your defined area onto a mask for that layer. Now you can clone away happily without running past the edges you have defined.
Another similar method would be to create a rough selection of a good area with the white wall texture you mention, CMND+J will cut this selection from your background layer onto a new layer, now move this over the area to be replaced and use the mask mentioned above for the layer. Unclick the little chain link icon between the layer and its mask, and you can move your new texture around within the masked area to suit.
If you are after a quick and rough job, use content aware.