drm/i915/gt: limit lmem allocation size to succeed on SmallBars

In case system is short on mappable memory (256MB on SmallBar) allocation
of two 1GB buffers will fail.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8300
Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230601144450.792228-1-andrzej.hajda@intel.com

diff --git a/drivers/gpu/drm/i915/gt/selftest_tlb.c b/drivers/gpu/drm/i915/gt/selftest_tlb.c
index 4493c8518e91b214ba9460b5ac2ff88b92a20e1a..3bd6b540257b46c89b65de46a992e5eb9c3a0d06 100644 (file)
--- a/drivers/gpu/drm/i915/gt/selftest_tlb.c
+++ b/drivers/gpu/drm/i915/gt/selftest_tlb.c
@@ -190,11 +190,18 @@ out:
 
 static struct drm_i915_gem_object *create_lmem(struct intel_gt *gt)
 {
+       struct intel_memory_region *mr = gt->i915->mm.regions[INTEL_REGION_LMEM_0];
+       resource_size_t size = SZ_1G;
+
        /*
         * Allocation of largest possible page size allows to test all types
-        * of pages.
+        * of pages. To succeed with both allocations, especially in case of Small
+        * BAR, try to allocate no more than quarter of mappable memory.
         */
-       return i915_gem_object_create_lmem(gt->i915, SZ_1G, I915_BO_ALLOC_CONTIGUOUS);
+       if (mr && size > mr->io_size / 4)
+               size = mr->io_size / 4;
+
+       return i915_gem_object_create_lmem(gt->i915, size, I915_BO_ALLOC_CONTIGUOUS);
 }
 
 static struct drm_i915_gem_object *create_smem(struct intel_gt *gt)