Start a new file, mine is 500x500.

Then create a new layer. Use the rectangular marquee tool to create a selection half of the whole canvas and fill the selection with black like the image on the left.

Now apply this filter to the layer:
Filter » Distort » Twirl
Angle: 999

Now press CTRL+F (or Filter » Twirl) to reapply this filter.

Now we want to load the selection of the spiral, to do this, move your cursor over to the spiral layer's (named Layer 1) icon and CTRL+Click.

See below

Now open the "Paths" pallette, it should be on the same panel as your layers, if not, go to Windows » Paths

Now in the Paths pallette, click the "Make new path from selection" Button. This will create a new path layer with the converted selection into vector.

Switch back to the Layers pallette, and you should see a path version of your spiral. You can even hide your spiral's layer to see your complete paths.

Select your Type tool, then in your Paragraphs pallete (Windows » Paragraphs), set your text align to "Right Align"

Then move your text cursor over to the center of the spiral until it changes to .

Then click to type. While typing, your text should follow the path of the spiral outward.

To hide the paths so you can see your text better, press CTRL+H.