Reviewed-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
On 9/30/2022 3:47 PM, Matthew Auld wrote:
On small-bar systems we could be given something non-mappable here,
which leads to nasty oops. Make this nicer by checking if the resource
is mappable or not, and return an error otherwise.
v2: drop GEM_BUG_ON(flags & I915_BO_ALLOC_GPU_ONLY)
Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Jianshui Yu <jianshui.yu@xxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Nirmoy Das <nirmoy.das@xxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_object.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index 369006c5317f..62495d5d0038 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -444,6 +444,16 @@ i915_gem_object_read_from_page_iomap(struct drm_i915_gem_object *obj, u64 offset
io_mapping_unmap(src_map);
}
+static bool object_has_mappable_iomem(struct drm_i915_gem_object *obj)
+{
+ GEM_BUG_ON(!i915_gem_object_has_iomem(obj));
+
+ if (IS_DGFX(to_i915(obj->base.dev)))
+ return i915_ttm_resource_mappable(i915_gem_to_ttm(obj)->resource);
+
+ return true;
+}
+
/**
* i915_gem_object_read_from_page - read data from the page of a GEM object
* @obj: GEM object to read from
@@ -466,7 +476,7 @@ int i915_gem_object_read_from_page(struct drm_i915_gem_object *obj, u64 offset,
if (i915_gem_object_has_struct_page(obj))
i915_gem_object_read_from_page_kmap(obj, offset, dst, size);
- else if (i915_gem_object_has_iomem(obj))
+ else if (i915_gem_object_has_iomem(obj) && object_has_mappable_iomem(obj))
i915_gem_object_read_from_page_iomap(obj, offset, dst, size);
else
return -ENODEV;
