drm/i915: Support 64b execbuf

Previously, our code only had a 32b offset value for where the
batchbuffer starts. With full PPGTT, and 64b canonical GPU address
space, that is an insufficient value. The code to expand is pretty
straight forward, and only one platform needs to do anything with the
extra bits.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Rafael Barbalho <rafael.barbalho@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_gem_execbuffer.c

@@ -1049,7 +1049,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 	struct i915_hw_context *ctx;
 	struct i915_address_space *vm;
 	const u32 ctx_id = i915_execbuffer2_get_context_id(*args);
-	u32 exec_start = args->batch_start_offset, exec_len;
+	u64 exec_start = args->batch_start_offset, exec_len;
 	u32 mask, flags;
 	int ret, mode, i;
 	bool need_relocs;

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -1210,7 +1210,7 @@ gen8_ring_put_irq(struct intel_ring_buffer *ring)
 
 static int
 i965_dispatch_execbuffer(struct intel_ring_buffer *ring,
-			 u32 offset, u32 length,
+			 u64 offset, u32 length,
 			 unsigned flags)
 {
 	int ret;
@@ -1233,7 +1233,7 @@ i965_dispatch_execbuffer(struct intel_ring_buffer *ring,
 #define I830_BATCH_LIMIT (256*1024)
 static int
 i830_dispatch_execbuffer(struct intel_ring_buffer *ring,
-				u32 offset, u32 len,
+				u64 offset, u32 len,
 				unsigned flags)
 {
 	int ret;
@@ -1284,7 +1284,7 @@ i830_dispatch_execbuffer(struct intel_ring_buffer *ring,
 
 static int
 i915_dispatch_execbuffer(struct intel_ring_buffer *ring,
-			 u32 offset, u32 len,
+			 u64 offset, u32 len,
 			 unsigned flags)
 {
 	int ret;
@@ -1797,7 +1797,7 @@ static int gen6_bsd_ring_flush(struct intel_ring_buffer *ring,
 
 static int
 gen8_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
-			      u32 offset, u32 len,
+			      u64 offset, u32 len,
 			      unsigned flags)
 {
 	struct drm_i915_private *dev_priv = ring->dev->dev_private;
@@ -1811,8 +1811,8 @@ gen8_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
 
 	/* FIXME(BDW): Address space and security selectors. */
 	intel_ring_emit(ring, MI_BATCH_BUFFER_START_GEN8 | (ppgtt<<8));
-	intel_ring_emit(ring, offset);
-	intel_ring_emit(ring, 0);
+	intel_ring_emit(ring, lower_32_bits(offset));
+	intel_ring_emit(ring, upper_32_bits(offset));
 	intel_ring_emit(ring, MI_NOOP);
 	intel_ring_advance(ring);
 
@@ -1821,7 +1821,7 @@ gen8_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
 
 static int
 hsw_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
-			      u32 offset, u32 len,
+			      u64 offset, u32 len,
 			      unsigned flags)
 {
 	int ret;
@@ -1842,7 +1842,7 @@ hsw_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
 
 static int
 gen6_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
-			      u32 offset, u32 len,
+			      u64 offset, u32 len,
 			      unsigned flags)
 {
 	int ret;

drivers/gpu/drm/i915/intel_ringbuffer.h

@@ -112,7 +112,7 @@ struct  intel_ring_buffer {
 	void		(*set_seqno)(struct intel_ring_buffer *ring,
 				     u32 seqno);
 	int		(*dispatch_execbuffer)(struct intel_ring_buffer *ring,
-					       u32 offset, u32 length,
+					       u64 offset, u32 length,
 					       unsigned flags);
 #define I915_DISPATCH_SECURE 0x1
 #define I915_DISPATCH_PINNED 0x2