xref: /netbsd-src/sys/external/bsd/drm2/dist/drm/nouveau/nvkm/subdev/bios/nouveau_nvkm_subdev_bios_ramcfg.c (revision 41ec02673d281bbb3d38e6c78504ce6e30c228c1)
1 /*	$NetBSD: nouveau_nvkm_subdev_bios_ramcfg.c,v 1.3 2021/12/18 23:45:38 riastradh Exp $	*/
2 
3 /*
4  * Copyright 2013 Red Hat Inc.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22  * OTHER DEALINGS IN THE SOFTWARE.
23  *
24  * Authors: Ben Skeggs <bskeggs@redhat.com>
25  */
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_bios_ramcfg.c,v 1.3 2021/12/18 23:45:38 riastradh Exp $");
28 
29 #include <subdev/bios.h>
30 #include <subdev/bios/bit.h>
31 #include <subdev/bios/ramcfg.h>
32 #include <subdev/bios/M0203.h>
33 
34 static u8
nvbios_ramcfg_strap(struct nvkm_subdev * subdev)35 nvbios_ramcfg_strap(struct nvkm_subdev *subdev)
36 {
37 	return (nvkm_rd32(subdev->device, 0x101000) & 0x0000003c) >> 2;
38 }
39 
40 u8
nvbios_ramcfg_count(struct nvkm_bios * bios)41 nvbios_ramcfg_count(struct nvkm_bios *bios)
42 {
43 	struct bit_entry bit_M;
44 
45 	if (!bit_entry(bios, 'M', &bit_M)) {
46 		if (bit_M.version == 1 && bit_M.length >= 5)
47 			return nvbios_rd08(bios, bit_M.offset + 2);
48 		if (bit_M.version == 2 && bit_M.length >= 3)
49 			return nvbios_rd08(bios, bit_M.offset + 0);
50 	}
51 
52 	return 0x00;
53 }
54 
55 u8
nvbios_ramcfg_index(struct nvkm_subdev * subdev)56 nvbios_ramcfg_index(struct nvkm_subdev *subdev)
57 {
58 	struct nvkm_bios *bios = subdev->device->bios;
59 	u8 strap = nvbios_ramcfg_strap(subdev);
60 	u32 xlat = 0x00000000;
61 	struct bit_entry bit_M;
62 	struct nvbios_M0203E M0203E;
63 	u8 ver, hdr;
64 
65 	if (!bit_entry(bios, 'M', &bit_M)) {
66 		if (bit_M.version == 1 && bit_M.length >= 5)
67 			xlat = nvbios_rd16(bios, bit_M.offset + 3);
68 		if (bit_M.version == 2 && bit_M.length >= 3) {
69 			/*XXX: is M ever shorter than this?
70 			 *     if not - what is xlat used for now?
71 			 *     also - sigh..
72 			 */
73 			if (bit_M.length >= 7 &&
74 			    nvbios_M0203Em(bios, strap, &ver, &hdr, &M0203E))
75 				return M0203E.group;
76 			xlat = nvbios_rd16(bios, bit_M.offset + 1);
77 		}
78 	}
79 
80 	if (xlat)
81 		strap = nvbios_rd08(bios, xlat + strap);
82 	return strap;
83 }
84