drm/i915/gem: Apply lmem size restriction to get_pages

When creating a handle, it is just that, an abstract handle. The fact
that we cannot currently support a handle larger than the size of the
backing storage is an artifact of our whole-object-at-a-time handling in
get_pages() and being an implementation limitation is best handled at
that point -- similar to shmem, where we only barf when asked to
populate the whole object if larger than RAM. (Pinning the whole object
at a time is major hindrance that we are likely to have to overcome in
the near future.) In the case of the buddy allocator, the late check is
preferable as the request size may often be smaller than the required
size.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191216122603.2598155-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
index 0e2bf6b7e143f9a4926af5098fa9c6b815c32fb4..520cc9cac471f72c2ebf5a015c4dc8cf876e7d28 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
@@ -79,9 +79,6 @@ __i915_gem_lmem_object_create(struct intel_memory_region *mem,
        struct drm_i915_private *i915 = mem->i915;
        struct drm_i915_gem_object *obj;
 
-       if (size > BIT(mem->mm.max_order) * mem->mm.chunk_size)
-               return ERR_PTR(-E2BIG);
-
        obj = i915_gem_object_alloc();
        if (!obj)
                return ERR_PTR(-ENOMEM);

diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
index 3f992491f537b88853fd373cf01e24d6e6d28777..497c367a79ca334be07cd6ec6261666a7afdb00e 100644 (file)
--- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
@@ -1420,7 +1420,7 @@ static int igt_ppgtt_smoke_huge(void *arg)
 
                err = i915_gem_object_pin_pages(obj);
                if (err) {
-                       if (err == -ENXIO) {
+                       if (err == -ENXIO || err == -E2BIG) {
                                i915_gem_object_put(obj);
                                size >>= 1;
                                goto try_again;

diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
index baaeaecc64aff00f49091b6a608a84e2e27a34b0..e24c280e5930df6905d3124e992a4085e45b60ec 100644 (file)
--- a/drivers/gpu/drm/i915/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/intel_memory_region.c
@@ -73,6 +73,9 @@ __intel_memory_region_get_pages_buddy(struct intel_memory_region *mem,
                min_order = ilog2(size) - ilog2(mem->mm.chunk_size);
        }
 
+       if (size > BIT(mem->mm.max_order) * mem->mm.chunk_size)
+               return -E2BIG;
+
        n_pages = size >> ilog2(mem->mm.chunk_size);
 
        mutex_lock(&mem->mm_lock);