[PATCH] drm/amdkfd: fix missing L2 cache info in topology

[Eric Huang]

In some ASICs L2 cache info may miss in kfd topology,
because the first bitmap may be empty, that means
the first cu may be inactive, so to find the first
active cu will solve the issue.

Signed-off-by: Eric Huang <jinhuieric.huang at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
index 4936697e6fc2..73d95041a388 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
@@ -1665,17 +1665,31 @@ static int fill_in_l2_l3_pcache(struct kfd_cache_properties **props_ext,
 				int cache_type, unsigned int cu_processor_id,
 				struct kfd_node *knode)
 {
-	unsigned int cu_sibling_map_mask;
+	unsigned int cu_sibling_map_mask = 0;
 	int first_active_cu;
 	int i, j, k, xcc, start, end;
 	int num_xcc = NUM_XCC(knode->xcc_mask);
 	struct kfd_cache_properties *pcache = NULL;
 	enum amdgpu_memory_partition mode;
 	struct amdgpu_device *adev = knode->adev;
+	bool found = false;
 
 	start = ffs(knode->xcc_mask) - 1;
 	end = start + num_xcc;
-	cu_sibling_map_mask = cu_info->bitmap[start][0][0];
+
+	/* To find the bitmap in the first active cu */
+	for (xcc = start; xcc < end && !found; xcc++) {
+		for (i = 0; i < gfx_info->max_shader_engines && !found; i++) {
+			for (j = 0; j < gfx_info->max_sh_per_se && !found; j++) {
+				if (cu_info->bitmap[xcc][i % 4][j % 4]) {
+					cu_sibling_map_mask =
+						cu_info->bitmap[xcc][i % 4][j % 4];
+					found = true;
+				}
+			}
+		}
+	}
+
 	cu_sibling_map_mask &=
 		((1 << pcache_info[cache_type].num_cu_shared) - 1);
 	first_active_cu = ffs(cu_sibling_map_mask);
-- 
2.34.1