drm/i915: make dsm struct resource centric

Now that we are using struct resource to track the stolen region, it is
more convenient if we track dsm in a resource as well.

v2: check range_overflow when writing to 32b registers (Chris)
    pepper in some comments (Chris)
v3: refit i915_stolen_to_dma()
v4: kill ggtt->stolen_size
v5: some more polish

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171211151822.20953-6-matthew.auld@intel.com

1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d57859cfad8e..1677b7e0d671 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1538,9 +1538,6 @@ struct i915_gem_mm {
 	 */
 	struct pagevec wc_stash;
 
-	/** Usable portion of the GTT for GEM */
-	dma_addr_t stolen_base; /* limited to low memory (32-bit) */
-
 	/**
 	 * tmpfs instance used for shmem backed objects
 	 */
@@ -2254,6 +2251,15 @@ struct drm_i915_private {
 
 	const struct intel_device_info info;
 
+	/**
+	 * Data Stolen Memory - aka "i915 stolen memory" gives us the start and
+	 * end of stolen which we can optionally use to create GEM objects
+	 * backed by stolen memory. Note that ggtt->stolen_usable_size tells us
+	 * exactly how much of this we are actually allowed to use, given that
+	 * some portion of it is in fact reserved for use by hardware functions.
+	 */
+	struct resource dsm;
+
 	void __iomem *regs;
 
 	struct intel_uncore uncore;