From b32456ae5b91b8a98e0fc196cd45ff803141d967 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 16 Dec 2019 12:26:03 +0000
Subject: drm/i915/gem: Apply lmem size restriction to get_pages
Git-commit: 0a9a5532d2962a74004e041eeb2217de930f8c27
Patch-mainline: v5.6-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

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
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/gem/i915_gem_lmem.c        | 3 ---
 drivers/gpu/drm/i915/gem/selftests/huge_pages.c | 2 +-
 drivers/gpu/drm/i915/intel_memory_region.c      | 3 +++
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
index 0e2bf6b7e143..520cc9cac471 100644
--- 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 3f992491f537..497c367a79ca 100644
--- 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 baaeaecc64af..e24c280e5930 100644
--- 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);
-- 
2.28.0