drm/nv20-nv40: add memory type detection

NV20/NV30 is partially educated guesswork at this point, based on any
information around about available memory types and a horribly unspeakable
amount of vbios image scouring.  I'm not entirely certain the GDDR3 define
is correct, I have not spotted a single vbios with that value yet (though
it is mentioned in some 1218-using nv4x vbios), but there are reports that
some nv3x did use it..

NV40(100914) confirmed by switching an NV49 to DDR1/DDR2 values and making
sure that the binary driver behaviour showed it had detected DDR1/DDR2
instead of GDDR3 before dying horribly.

NV40(100474) confirmed by doing much the same task as above on an NV44,
except this was *much* easier as changing the values didn't seem to have
any noticable effect on the memory controller aside from changing the
binary driver's behaviour.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nv40_fb.c b/drivers/gpu/drm/nouveau/nv40_fb.c
index f0ac2a768c67..7fbcb334c096 100644
--- a/drivers/gpu/drm/nouveau/nv40_fb.c
+++ b/drivers/gpu/drm/nouveau/nv40_fb.c
@@ -72,6 +72,51 @@ nv44_fb_init_gart(struct drm_device *dev)
 }
 
 int
+nv40_fb_vram_init(struct drm_device *dev)
+{
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+
+	/* 0x001218 is actually present on a few other NV4X I looked at,
+	 * and even contains sane values matching 0x100474.  From looking
+	 * at various vbios images however, this isn't the case everywhere.
+	 * So, I chose to use the same regs I've seen NVIDIA reading around
+	 * the memory detection, hopefully that'll get us the right numbers
+	 */
+	if (dev_priv->chipset == 0x40) {
+		u32 pbus1218 = nv_rd32(dev, 0x001218);
+		switch (pbus1218 & 0x00000300) {
+		case 0x00000000: dev_priv->vram_type = NV_MEM_TYPE_SDRAM; break;
+		case 0x00000100: dev_priv->vram_type = NV_MEM_TYPE_DDR1; break;
+		case 0x00000200: dev_priv->vram_type = NV_MEM_TYPE_GDDR3; break;
+		case 0x00000300: dev_priv->vram_type = NV_MEM_TYPE_DDR2; break;
+		}
+	} else
+	if (dev_priv->chipset == 0x49 || dev_priv->chipset == 0x4b) {
+		u32 pfb914 = nv_rd32(dev, 0x100914);
+		switch (pfb914 & 0x00000003) {
+		case 0x00000000: dev_priv->vram_type = NV_MEM_TYPE_DDR1; break;
+		case 0x00000001: dev_priv->vram_type = NV_MEM_TYPE_DDR2; break;
+		case 0x00000002: dev_priv->vram_type = NV_MEM_TYPE_GDDR3; break;
+		case 0x00000003: break;
+		}
+	} else
+	if (dev_priv->chipset != 0x4e) {
+		u32 pfb474 = nv_rd32(dev, 0x100474);
+		if (pfb474 & 0x00000004)
+			dev_priv->vram_type = NV_MEM_TYPE_GDDR3;
+		if (pfb474 & 0x00000002)
+			dev_priv->vram_type = NV_MEM_TYPE_DDR2;
+		if (pfb474 & 0x00000001)
+			dev_priv->vram_type = NV_MEM_TYPE_DDR1;
+	} else {
+		dev_priv->vram_type = NV_MEM_TYPE_STOLEN;
+	}
+
+	dev_priv->vram_size = nv_rd32(dev, 0x10020c) & 0xff000000;
+	return 0;
+}
+
+int
 nv40_fb_init(struct drm_device *dev)
 {
 	struct drm_nouveau_private *dev_priv = dev->dev_private;