[PATCH 23/25] drm/i915/gem/mman: only allow WC for lmem

[Matthew Auld]

For dgfx where we have lmem and ttm, we can only support single mmap
mode for the lifetime of the object, and for lmem objects this should be
WC, so reject any other mapping modes for mmap_offset.

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_mman.c   |  6 ++++++
 drivers/gpu/drm/i915/gem/i915_gem_object.c | 14 ++++++++++++++
 drivers/gpu/drm/i915/gem/i915_gem_object.h |  4 ++++
 3 files changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index 3d78f4d59cb2..216e05132064 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -690,6 +690,12 @@ __assign_mmap_offset(struct drm_file *file,
 		goto out;
 	}
 
+	if (mmap_type != I915_MMAP_TYPE_WC &&
+	    i915_gem_object_placements_contain_type(obj, INTEL_MEMORY_LOCAL)) {
+		err = -ENODEV;
+		goto out;
+	}
+
 	mmo = mmap_offset_attach(obj, mmap_type, file);
 	if (IS_ERR(mmo)) {
 		err = PTR_ERR(mmo);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index 8484d8940531..518490024fe5 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -475,6 +475,20 @@ bool i915_gem_object_migratable(struct drm_i915_gem_object *obj)
 	return obj->mm.n_placements > 1;
 }
 
+bool i915_gem_object_placements_contain_type(struct drm_i915_gem_object *obj,
+					     enum intel_memory_type type)
+{
+	unsigned int i;
+
+	/* TODO: consider maybe storing as a mask when doing gem_create_ext */
+	for (i = 0; i < obj->mm.n_placements; i++) {
+		if (obj->mm.placements[i]->type == type)
+			return true;
+	}
+
+	return false;
+}
+
 void i915_gem_init__objects(struct drm_i915_private *i915)
 {
 	INIT_WORK(&i915->mm.free_work, __i915_gem_free_work);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index ff59e6c640e6..49fd1f4ec262 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -12,6 +12,7 @@
 #include <drm/drm_device.h>
 
 #include "display/intel_frontbuffer.h"
+#include "intel_memory_region.h"
 #include "i915_gem_object_types.h"
 #include "i915_gem_gtt.h"
 #include "i915_vma_types.h"
@@ -600,6 +601,9 @@ bool i915_gem_object_migratable(struct drm_i915_gem_object *obj);
 
 bool i915_gem_object_validates_to_lmem(struct drm_i915_gem_object *obj);
 
+bool i915_gem_object_placements_contain_type(struct drm_i915_gem_object *obj,
+					     enum intel_memory_type type);
+
 #ifdef CONFIG_MMU_NOTIFIER
 static inline bool
 i915_gem_object_is_userptr(struct drm_i915_gem_object *obj)
-- 
2.26.3