[Intel-gfx] [PATCH 15/16] drm/i915: Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset

[Michel Thierry]

There are some allocations that must be only referenced by 32bit
offsets. To limit the chances of having the first 4GB already full,
objects not requiring this workaround don't use the first 2 PDPs.

User must pass EXEC_OBJECT_NEEDS_32BADDRESS flag to indicate it needs a
32b address.

The flag is ignored in 32b PPGTT.

Signed-off-by: Michel Thierry <michel.thierry at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h            |  1 +
 drivers/gpu/drm/i915/i915_gem.c            | 11 +++++++++++
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |  3 +++
 include/uapi/drm/i915_drm.h                |  3 ++-
 4 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 32493f0..a06f19c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2714,6 +2714,7 @@ void i915_gem_vma_destroy(struct i915_vma *vma);
 #define PIN_OFFSET_BIAS	(1<<3)
 #define PIN_USER	(1<<4)
 #define PIN_UPDATE	(1<<5)
+#define PIN_FULL_RANGE	(1<<6)
 #define PIN_OFFSET_MASK (~4095)
 int __must_check
 i915_gem_object_pin(struct drm_i915_gem_object *obj,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index acd928d..a133b7d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3713,6 +3713,17 @@ i915_gem_object_bind_to_vm(struct drm_i915_gem_object *obj,
 						   obj->tiling_mode,
 						   false);
 		size = flags & PIN_MAPPABLE ? fence_size : obj->base.size;
+
+		/* Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset,
+		 * limit address to 4GB-1 for objects requiring this wa; for
+		 * others, start on the 2nd PDP.
+		 */
+		if (USES_FULL_48BIT_PPGTT(dev)) {
+			if (flags & PIN_FULL_RANGE)
+				start += (2ULL << GEN8_PDPE_SHIFT);
+			else
+				end = ((4ULL << GEN8_PDPE_SHIFT) - 1);
+		}
 	}
 
 	if (alignment == 0)
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index bd0e4bd..3de7f0f 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -588,6 +588,9 @@ i915_gem_execbuffer_reserve_vma(struct i915_vma *vma,
 	if (entry->flags & EXEC_OBJECT_NEEDS_GTT)
 		flags |= PIN_GLOBAL;
 
+	if (!(entry->flags & EXEC_OBJECT_NEEDS_32BADDRESS))
+		flags |= PIN_FULL_RANGE;
+
 	if (!drm_mm_node_allocated(&vma->node)) {
 		if (entry->flags & __EXEC_OBJECT_NEEDS_MAP)
 			flags |= PIN_GLOBAL | PIN_MAPPABLE;
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 4851d66..ebdf6dd 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -680,7 +680,8 @@ struct drm_i915_gem_exec_object2 {
 #define EXEC_OBJECT_NEEDS_FENCE (1<<0)
 #define EXEC_OBJECT_NEEDS_GTT	(1<<1)
 #define EXEC_OBJECT_WRITE	(1<<2)
-#define __EXEC_OBJECT_UNKNOWN_FLAGS -(EXEC_OBJECT_WRITE<<1)
+#define EXEC_OBJECT_NEEDS_32BADDRESS (1<<3)
+#define __EXEC_OBJECT_UNKNOWN_FLAGS -(EXEC_OBJECT_NEEDS_32BADDRESS<<1)
 	__u64 flags;
 
 	__u64 rsvd1;
-- 
2.4.0