drm/amdgpu: fix incorrect number of active RBs for gfx12

The RB bitmap should be global active RB bitmap &
active RB bitmap based on active SA.

Signed-off-by: Tim Huang <tim.huang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v12_0.c

@@ -1623,6 +1623,7 @@ static u32 gfx_v12_0_get_rb_active_bitmap(struct amdgpu_device *adev)
 
 static void gfx_v12_0_setup_rb(struct amdgpu_device *adev)
 {
+	u32 rb_bitmap_per_sa;
 	u32 rb_bitmap_width_per_sa;
 	u32 max_sa;
 	u32 active_sa_bitmap;
@@ -1640,12 +1641,14 @@ static void gfx_v12_0_setup_rb(struct amdgpu_device *adev)
 		 adev->gfx.config.max_sh_per_se;
 	rb_bitmap_width_per_sa = adev->gfx.config.max_backends_per_se /
 				 adev->gfx.config.max_sh_per_se;
+	rb_bitmap_per_sa = amdgpu_gfx_create_bitmask(rb_bitmap_width_per_sa);
+
 	for (i = 0; i < max_sa; i++) {
 		if (active_sa_bitmap & (1 << i))
-			active_rb_bitmap |= (0x3 << (i * rb_bitmap_width_per_sa));
+			active_rb_bitmap |= (rb_bitmap_per_sa << (i * rb_bitmap_width_per_sa));
 	}
 
-	active_rb_bitmap |= global_active_rb_bitmap;
+	active_rb_bitmap &= global_active_rb_bitmap;
 	adev->gfx.config.backend_enable_mask = active_rb_bitmap;
 	adev->gfx.config.num_rbs = hweight32(active_rb_bitmap);
 }