drm/radeon: allow MIP_ADDRESS=0 for MSAA textures on Evergreen

MIP_ADDRESS should point to the resolved FMASK for an MSAA texture.
Setting MIP_ADDRESS to 0 means the FMASK pointer is invalid (the GPU
won't read the memory then).

The userspace has to set MIP_ADDRESS to 0 and *not* emit any relocation
for it.
Signed-off-by: Marek Olšák <maraeo@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/radeon/evergreen_cs.c

@@ -846,6 +846,16 @@ static int evergreen_cs_track_validate_texture(struct radeon_cs_parser *p,
 		return -EINVAL;
 	}
 
+	if (!mipmap) {
+		if (llevel) {
+			dev_warn(p->dev, "%s:%i got NULL MIP_ADDRESS relocation\n",
+				 __func__, __LINE__);
+			return -EINVAL;
+		} else {
+			return 0; /* everything's ok */
+		}
+	}
+
 	/* check mipmap size */
 	for (i = 1; i <= llevel; i++) {
 		unsigned w, h, d;
@@ -1080,6 +1090,27 @@ static int evergreen_cs_packet_next_reloc(struct radeon_cs_parser *p,
 	return 0;
 }
 
+/**
+ * evergreen_cs_packet_next_is_pkt3_nop() - test if the next packet is NOP
+ * @p:		structure holding the parser context.
+ *
+ * Check if the next packet is a relocation packet3.
+ **/
+static bool evergreen_cs_packet_next_is_pkt3_nop(struct radeon_cs_parser *p)
+{
+	struct radeon_cs_packet p3reloc;
+	int r;
+
+	r = evergreen_cs_packet_parse(p, &p3reloc, p->idx);
+	if (r) {
+		return false;
+	}
+	if (p3reloc.type != PACKET_TYPE3 || p3reloc.opcode != PACKET3_NOP) {
+		return false;
+	}
+	return true;
+}
+
 /**
  * evergreen_cs_packet_next_vline() - parse userspace VLINE packet
  * @parser:		parser structure holding parsing context.
@@ -2330,7 +2361,7 @@ static int evergreen_packet3_check(struct radeon_cs_parser *p,
 		for (i = 0; i < (pkt->count / 8); i++) {
 			struct radeon_bo *texture, *mipmap;
 			u32 toffset, moffset;
-			u32 size, offset;
+			u32 size, offset, mip_address, tex_dim;
 
 			switch (G__SQ_CONSTANT_TYPE(radeon_get_ib_value(p, idx+1+(i*8)+7))) {
 			case SQ_TEX_VTX_VALID_TEXTURE:
@@ -2359,14 +2390,28 @@ static int evergreen_packet3_check(struct radeon_cs_parser *p,
 				}
 				texture = reloc->robj;
 				toffset = (u32)((reloc->lobj.gpu_offset >> 8) & 0xffffffff);
+
 				/* tex mip base */
-				r = evergreen_cs_packet_next_reloc(p, &reloc);
-				if (r) {
-					DRM_ERROR("bad SET_RESOURCE (tex)\n");
-					return -EINVAL;
+				tex_dim = ib[idx+1+(i*8)+0] & 0x7;
+				mip_address = ib[idx+1+(i*8)+3];
+
+				if ((tex_dim == SQ_TEX_DIM_2D_MSAA || tex_dim == SQ_TEX_DIM_2D_ARRAY_MSAA) &&
+				    !mip_address &&
+				    !evergreen_cs_packet_next_is_pkt3_nop(p)) {
+					/* MIP_ADDRESS should point to FMASK for an MSAA texture.
+					 * It should be 0 if FMASK is disabled. */
+					moffset = 0;
+					mipmap = NULL;
+				} else {
+					r = evergreen_cs_packet_next_reloc(p, &reloc);
+					if (r) {
+						DRM_ERROR("bad SET_RESOURCE (tex)\n");
+						return -EINVAL;
+					}
+					moffset = (u32)((reloc->lobj.gpu_offset >> 8) & 0xffffffff);
+					mipmap = reloc->robj;
 				}
-				moffset = (u32)((reloc->lobj.gpu_offset >> 8) & 0xffffffff);
-				mipmap = reloc->robj;
+
 				r = evergreen_cs_track_validate_texture(p, texture, mipmap, idx+1+(i*8));
 				if (r)
 					return r;

drivers/gpu/drm/radeon/radeon_drv.c

@@ -65,9 +65,10 @@
  *   2.21.0 - r600-r700: FMASK and CMASK
  *   2.22.0 - r600 only: RESOLVE_BOX allowed
  *   2.23.0 - allow STRMOUT_BASE_UPDATE on RS780 and RS880
+ *   2.24.0 - eg only: allow MIP_ADDRESS=0 for MSAA textures
  */
 #define KMS_DRIVER_MAJOR	2
-#define KMS_DRIVER_MINOR	23
+#define KMS_DRIVER_MINOR	24
 #define KMS_DRIVER_PATCHLEVEL	0
 int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags);
 int radeon_driver_unload_kms(struct drm_device *dev);