1 /*
2  * Copyright 2013 Red Hat Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: Ben Skeggs <bskeggs@redhat.com>
23  */
24 #include <subdev/bios.h>
25 #include <subdev/bios/bit.h>
26 #include <subdev/bios/ramcfg.h>
27 #include <subdev/bios/M0203.h>
28 
29 static u8
30 nvbios_ramcfg_strap(struct nvkm_subdev *subdev)
31 {
32 	return (nvkm_rd32(subdev->device, 0x101000) & 0x0000003c) >> 2;
33 }
34 
35 u8
36 nvbios_ramcfg_count(struct nvkm_bios *bios)
37 {
38 	struct bit_entry bit_M;
39 
40 	if (!bit_entry(bios, 'M', &bit_M)) {
41 		if (bit_M.version == 1 && bit_M.length >= 5)
42 			return nvbios_rd08(bios, bit_M.offset + 2);
43 		if (bit_M.version == 2 && bit_M.length >= 3)
44 			return nvbios_rd08(bios, bit_M.offset + 0);
45 	}
46 
47 	return 0x00;
48 }
49 
50 u8
51 nvbios_ramcfg_index(struct nvkm_subdev *subdev)
52 {
53 	struct nvkm_bios *bios = subdev->device->bios;
54 	u8 strap = nvbios_ramcfg_strap(subdev);
55 	u32 xlat = 0x00000000;
56 	struct bit_entry bit_M;
57 	struct nvbios_M0203E M0203E;
58 	u8 ver, hdr;
59 
60 	if (!bit_entry(bios, 'M', &bit_M)) {
61 		if (bit_M.version == 1 && bit_M.length >= 5)
62 			xlat = nvbios_rd16(bios, bit_M.offset + 3);
63 		if (bit_M.version == 2 && bit_M.length >= 3) {
64 			/*XXX: is M ever shorter than this?
65 			 *     if not - what is xlat used for now?
66 			 *     also - sigh..
67 			 */
68 			if (bit_M.length >= 7 &&
69 			    nvbios_M0203Em(bios, strap, &ver, &hdr, &M0203E))
70 				return M0203E.group;
71 			xlat = nvbios_rd16(bios, bit_M.offset + 1);
72 		}
73 	}
74 
75 	if (xlat)
76 		strap = nvbios_rd08(bios, xlat + strap);
77 	return strap;
78 }
79