[PATCH v2 02/15] drm/i915/ttm: require mappable by default

[Matthew Auld]

On devices with non-mappable LMEM ensure we always allocate the pages
within the mappable portion. For now we assume that all LMEM buffers
will require CPU access, which is also inline with pretty much all
current kernel internal users. In the next patch we will introduce a new
flag to override this behaviour.

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 4 ++++
 drivers/gpu/drm/i915/intel_region_ttm.c | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index e9399f7b3e67..41e94d09e742 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -128,6 +128,10 @@ i915_ttm_place_from_region(const struct intel_memory_region *mr,
 
 	if (flags & I915_BO_ALLOC_CONTIGUOUS)
 		place->flags = TTM_PL_FLAG_CONTIGUOUS;
+	if (mr->io_size && mr->io_size < mr->total) {
+		place->fpfn = 0;
+		place->lpfn = mr->io_size >> PAGE_SHIFT;
+	}
 }
 
 static void
diff --git a/drivers/gpu/drm/i915/intel_region_ttm.c b/drivers/gpu/drm/i915/intel_region_ttm.c
index f2b888c16958..4689192d5e8d 100644
--- a/drivers/gpu/drm/i915/intel_region_ttm.c
+++ b/drivers/gpu/drm/i915/intel_region_ttm.c
@@ -199,6 +199,11 @@ intel_region_ttm_resource_alloc(struct intel_memory_region *mem,
 	struct ttm_resource *res;
 	int ret;
 
+	if (mem->io_size && mem->io_size < mem->total) {
+		place.fpfn = 0;
+		place.lpfn = mem->io_size >> PAGE_SHIFT;
+	}
+
 	mock_bo.base.size = size;
 	place.flags = flags;
 
-- 
2.34.1