drm/nouveau: Add getparam to get available PGRAPH units.

On nv50, this will be needed by applications using CUDA to know
how much stack/local memory to allocate.

Signed-off-by: Marcin Kościelnicki <koriakin@0x04.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

2 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_reg.h b/drivers/gpu/drm/nouveau/nouveau_reg.h
index 251f1b3b38b9..aa9b310e41be 100644
--- a/drivers/gpu/drm/nouveau/nouveau_reg.h
+++ b/drivers/gpu/drm/nouveau/nouveau_reg.h
@@ -99,6 +99,7 @@
  * the card will hang early on in the X init process.
  */
 #    define NV_PMC_ENABLE_UNK13                               (1<<13)
+#define NV40_PMC_GRAPH_UNITS                               0x00001540
 #define NV40_PMC_BACKLIGHT                                 0x000015f0
 #       define NV40_PMC_BACKLIGHT_MASK                     0x001f0000
 #define NV40_PMC_1700                                      0x00001700
diff --git a/drivers/gpu/drm/nouveau/nouveau_state.c b/drivers/gpu/drm/nouveau/nouveau_state.c
index 241e24d60eb4..fcd7610817a1 100644
--- a/drivers/gpu/drm/nouveau/nouveau_state.c
+++ b/drivers/gpu/drm/nouveau/nouveau_state.c
@@ -825,6 +825,15 @@ int nouveau_ioctl_getparam(struct drm_device *dev, void *data,
         case NOUVEAU_GETPARAM_VM_VRAM_BASE:
                 getparam->value = dev_priv->vm_vram_base;
                 break;
+        case NOUVEAU_GETPARAM_GRAPH_UNITS:
+                /* NV40 and NV50 versions are quite different, but register
+                 * address is the same. User is supposed to know the card
+                 * family anyway... */
+                if (dev_priv->chipset >= 0x40) {
+                        getparam->value = nv_rd32(dev, NV40_PMC_GRAPH_UNITS);
+                        break;
+                }
+                /* FALLTHRU */
         default:
                 NV_ERROR(dev, "unknown parameter %lld\n", getparam->param);
                 return -EINVAL;