drm/amdgpu/discovery: validate VCN and SDMA instances

Validate the VCN and SDMA instances against the driver
structure sizes to make sure we don't get into a
situation where the firmware reports more instances than
the driver supports.

Reviewed-by: Guchun Chen <guchun.chen@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
index 16cdfb3..47f0344 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
@@ -1130,13 +1130,24 @@ static int amdgpu_discovery_reg_base_init(struct amdgpu_device *adev)
                                adev->vcn.vcn_config[adev->vcn.num_vcn_inst] =
                                        ip->revision & 0xc0;
                                ip->revision &= ~0xc0;
-                               adev->vcn.num_vcn_inst++;
+                               if (adev->vcn.num_vcn_inst < AMDGPU_MAX_VCN_INSTANCES)
+                                       adev->vcn.num_vcn_inst++;
+                               else
+                                       dev_err(adev->dev, "Too many VCN instances: %d vs %d\n",
+                                               adev->vcn.num_vcn_inst + 1,
+                                               AMDGPU_MAX_VCN_INSTANCES);
                        }
                        if (le16_to_cpu(ip->hw_id) == SDMA0_HWID ||
                            le16_to_cpu(ip->hw_id) == SDMA1_HWID ||
                            le16_to_cpu(ip->hw_id) == SDMA2_HWID ||
-                           le16_to_cpu(ip->hw_id) == SDMA3_HWID)
-                               adev->sdma.num_instances++;
+                           le16_to_cpu(ip->hw_id) == SDMA3_HWID) {
+                               if (adev->sdma.num_instances < AMDGPU_MAX_SDMA_INSTANCES)
+                                       adev->sdma.num_instances++;
+                               else
+                                       dev_err(adev->dev, "Too many SDMA instances: %d vs %d\n",
+                                               adev->sdma.num_instances + 1,
+                                               AMDGPU_MAX_SDMA_INSTANCES);
+                       }
 
                        if (le16_to_cpu(ip->hw_id) == UMC_HWID)
                                adev->gmc.num_umc++;