From 8d36d650384cb2dd724241fa44760b241bb40a82 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Mon, 16 May 2022 14:12:33 -0400
Subject: drm/amdgpu/discovery: validate VCN and SDMA instances
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Git-commit: a0ccc717c4ab3ef572f023fdceffb4b6df496a0d
Patch-mainline: v5.19-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

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>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
index 16cdfb30b013..47f0344205ed 100644
--- 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++;
-- 
2.38.1