A fairly short one here, folks.  I've done a bit of research regarding which AMD graphics chips use at least GCN 1.0 architecture.  Since the apparent goal is to get all GCN first generation and later working with AMDGPU and -PRO, this is what I think may be a list of products that may possibly be destined to work with AMDGPU.  I can't guarantee any of this, of course, and your mileage may vary.

Let's hope for the best:

Radeon HD 7730
Radeon HD 7750
Radeon HD 7770 "GHz Edition"
Radeon HD 7790
Radeon HD 7850
Radeon HD 7870 "GHz Edition"
Radeon HD 7870 XT
Radeon HD 7950
Radeon HD 7950 Boost
Radeon HD 7970
Radeon HD 7970 "GHz Edition"
Radeon HD 7990

Radeon HD 7730M
Radeon HD 7750M
Radeon HD 7770M
Radeon HD 7850M
Radeon HD 7870M
Radeon HD 7970M

Radeon HD 8350
Radeon HD 8450
Radeon HD 8470
Radeon HD 8490
Radeon HD 8570
Radeon HD 8670
Radeon HD 8730
Radeon HD 8760
Radeon HD 8770
Radeon HD 8870
Radeon HD 8950
Radeon HD 8970
Radeon HD 8990
Radeon HD 8550M / 8630M
Radeon HD 8570M / 8650M
Radeon HD 8670M
Radeon HD 8690M
Radeon HD 8730M
Radeon HD 8750M
Radeon HD 8770M
Radeon HD 8790M
Radeon HD 8830M
Radeon HD 8850M
Radeon HD 8870M
Radeon HD 8970M

Radeon R5 240
Radeon R7 240
Radeon R7 250
Radeon R7 250X
Radeon R7 260
Radeon R7 260X
Radeon R7 265
Radeon R9 270
Radeon R9 270X
Radeon R9 280
Radeon R9 280X
Radeon R9 285
Radeon R9 290
Radeon R9 290X
Radeon R9 295X2
Radeon R5 M230
Radeon R5 M255
Radeon R7 M260
Radeon R7 M260X
Radeon R7 M265
Radeon R9 M265X
Radeon R9 M270X
Radeon R9 M275X
Radeon R9 M280X
Radeon R9 M290X
Radeon R9 M295X

Radeon R5 330
Radeon R5 340
Radeon R7 340
Radeon R7 350
Radeon R7 350
Radeon R7 360
Radeon R9 360
Radeon R7 370
Radeon R9 370
Radeon R9 370X
Radeon R9 380
Radeon R9 380
Radeon R9 380X
Radeon R9 390
Radeon R9 390X
Radeon R9 Fury
Radeon R9 Nano
Radeon R9 Fury X
Radeon Pro Duo

Radeon R5 M330
Radeon R5 M335
Radeon R7 M360
Radeon R9 M365X
Radeon R9 M370X
Radeon R9 M375
Radeon R9 M375X
Radeon R9 M380
Radeon R9 M385
Radeon R9 M385X
Radeon R9 M390
Radeon R9 M390X
Radeon R9 M395
Radeon R9 M395X

Radeon R5 430
Radeon R5 435
Radeon R7 430
Radeon R7 435
Radeon R7 450
Radeon R7 455
Radeon RX 460
Radeon RX 470
Radeon RX 480

Radeon R5 M420
Radeon R5 M430
Radeon R7 M435
Radeon R7 M440
Radeon R5 M445
Radeon R7 M460
Radeon R7 M465
Radeon R7 M465X
Radeon R9 M470
Radeon R9 M470X
Radeon RX 480M
Radeon R9 M485X

Some Kaveri APUs


Some Carrizo APUs

    AMD FX-8800P
    AMD PRO FX-8800B
    AMD A10-8700P
    AMD A8-8600P
    AMD A6-8500P
    AMD PRO A10-8700B
    AMD PRO A8-8600B
    AMD PRO A6-8500B
    AMD RX-418GD
    AMD RX-216GD


Legal Disclaimer:  I am not an Ubuntu apologist, but I do use Ubuntu and Kubuntu.  I am not a Fedora apologist, but I do use Fedora.  I am not a Windows apologist, but I do use Windows.  I'm not a FOSS apologist, but I use FOSS tools when I can and when they fit the job at hand.  I don't find any sense in a religious affiliation with tools and operating systems.  That's just asinine.