[PATCH libdrm v3 1/2] intel: Add EXEC_OBJECT_SUPPORTS_48B_ADDRESS flag

Michel Thierry michel.thierry at intel.com
Fri Aug 7 02:45:21 PDT 2015


Gen8+ supports 48-bit virtual addresses, but some objects must always be
allocated inside the 32-bit address range.

In specific, any resource used with flat/heapless (0x00000000-0xfffff000)
General State Heap (GSH) or Instruction State Heap (ISH) must be in a
32-bit range, because the General State Offset and Instruction State Offset
are limited to 32-bits.

The i915 driver has been modified to provide a flag to set when the 4GB
limit is not necessary in a given bo (EXEC_OBJECT_SUPPORTS_48B_ADDRESS).
48-bit range will only be used when explicitly requested.

Calls to the new drm_intel_bo_emit_reloc_48bit function will have this flag
set automatically, while calls to drm_intel_bo_emit_reloc will clear it.

v2: Make set/clear functions nops on pre-gen8 platforms, and use them
    internally in emit_reloc functions (Ben)
    s/48BADDRESS/48B_ADDRESS/ (Dave)
v3: Keep set/clear functions internal, no-one needs to use them directly.

References: http://lists.freedesktop.org/archives/intel-gfx/2015-July/072612.html
Cc: Ben Widawsky <ben at bwidawsk.net>
Cc: Dave Gordon <david.s.gordon at intel.com>
Signed-off-by: Michel Thierry <michel.thierry at intel.com>
---
 include/drm/i915_drm.h    |  3 ++-
 intel/intel_bufmgr.c      | 16 ++++++++++++++
 intel/intel_bufmgr.h      |  6 +++++-
 intel/intel_bufmgr_gem.c  | 54 +++++++++++++++++++++++++++++++++++++++++++----
 intel/intel_bufmgr_priv.h | 11 ++++++++++
 5 files changed, 84 insertions(+), 6 deletions(-)

diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
index ded43b1..426b25c 100644
--- a/include/drm/i915_drm.h
+++ b/include/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_SUPPORTS_48B_ADDRESS (1<<3)
+#define __EXEC_OBJECT_UNKNOWN_FLAGS -(EXEC_OBJECT_SUPPORTS_48B_ADDRESS<<1)
 	__u64 flags;
 
 	__u64 rsvd1;
diff --git a/intel/intel_bufmgr.c b/intel/intel_bufmgr.c
index 14ea9f9..0bd5191 100644
--- a/intel/intel_bufmgr.c
+++ b/intel/intel_bufmgr.c
@@ -202,6 +202,22 @@ drm_intel_bo_emit_reloc(drm_intel_bo *bo, uint32_t offset,
 			drm_intel_bo *target_bo, uint32_t target_offset,
 			uint32_t read_domains, uint32_t write_domain)
 {
+	if (bo->bufmgr->bo_clear_supports_48b_address)
+		bo->bufmgr->bo_clear_supports_48b_address(target_bo);
+
+	return bo->bufmgr->bo_emit_reloc(bo, offset,
+					 target_bo, target_offset,
+					 read_domains, write_domain);
+}
+
+int
+drm_intel_bo_emit_reloc_48bit(drm_intel_bo *bo, uint32_t offset,
+			drm_intel_bo *target_bo, uint32_t target_offset,
+			uint32_t read_domains, uint32_t write_domain)
+{
+	if (bo->bufmgr->bo_set_supports_48b_address)
+		bo->bufmgr->bo_set_supports_48b_address(target_bo);
+
 	return bo->bufmgr->bo_emit_reloc(bo, offset,
 					 target_bo, target_offset,
 					 read_domains, write_domain);
diff --git a/intel/intel_bufmgr.h b/intel/intel_bufmgr.h
index 285919e..8f91ffe 100644
--- a/intel/intel_bufmgr.h
+++ b/intel/intel_bufmgr.h
@@ -87,7 +87,8 @@ struct _drm_intel_bo {
 	/**
 	 * Last seen card virtual address (offset from the beginning of the
 	 * aperture) for the object.  This should be used to fill relocation
-	 * entries when calling drm_intel_bo_emit_reloc()
+	 * entries when calling drm_intel_bo_emit_reloc() or
+	 * drm_intel_bo_emit_reloc_48bit()
 	 */
 	uint64_t offset64;
 };
@@ -147,6 +148,9 @@ int drm_intel_bufmgr_check_aperture_space(drm_intel_bo ** bo_array, int count);
 int drm_intel_bo_emit_reloc(drm_intel_bo *bo, uint32_t offset,
 			    drm_intel_bo *target_bo, uint32_t target_offset,
 			    uint32_t read_domains, uint32_t write_domain);
+int drm_intel_bo_emit_reloc_48bit(drm_intel_bo *bo, uint32_t offset,
+				  drm_intel_bo *target_bo, uint32_t target_offset,
+				  uint32_t read_domains, uint32_t write_domain);
 int drm_intel_bo_emit_reloc_fence(drm_intel_bo *bo, uint32_t offset,
 				  drm_intel_bo *target_bo,
 				  uint32_t target_offset,
diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
index 41de396..713ed4e 100644
--- a/intel/intel_bufmgr_gem.c
+++ b/intel/intel_bufmgr_gem.c
@@ -140,6 +140,7 @@ typedef struct _drm_intel_bufmgr_gem {
 } drm_intel_bufmgr_gem;
 
 #define DRM_INTEL_RELOC_FENCE (1<<0)
+#define DRM_INTEL_RELOC_SUPPORTS_48B_ADDRESS (2<<0)
 
 typedef struct _drm_intel_reloc_target_info {
 	drm_intel_bo *bo;
@@ -237,6 +238,14 @@ struct _drm_intel_bo_gem {
 	bool is_userptr;
 
 	/**
+	 * Boolean of whether this buffer can be in the whole 48-bit address.
+	 *
+	 * By default, buffers will be keep in a 32-bit range, unless this
+	 * flag is explicitly set.
+	 */
+	bool supports_48b_address;
+
+	/**
 	 * Size in bytes of this buffer and its relocation descendents.
 	 *
 	 * Used to avoid costly tree walking in
@@ -463,13 +472,18 @@ drm_intel_add_validate_buffer(drm_intel_bo *bo)
 }
 
 static void
-drm_intel_add_validate_buffer2(drm_intel_bo *bo, int need_fence)
+drm_intel_add_validate_buffer2(drm_intel_bo *bo, int need_fence,
+			       int supports_48b_address)
 {
 	drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *)bo->bufmgr;
 	drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *)bo;
 	int index;
 
 	if (bo_gem->validate_index != -1) {
+		if (supports_48b_address) {
+			bufmgr_gem->exec2_objects[bo_gem->validate_index].flags |=
+				EXEC_OBJECT_SUPPORTS_48B_ADDRESS;
+		}
 		if (need_fence)
 			bufmgr_gem->exec2_objects[bo_gem->validate_index].flags |=
 				EXEC_OBJECT_NEEDS_FENCE;
@@ -508,6 +522,10 @@ drm_intel_add_validate_buffer2(drm_intel_bo *bo, int need_fence)
 		bufmgr_gem->exec2_objects[index].flags |=
 			EXEC_OBJECT_NEEDS_FENCE;
 	}
+	if (supports_48b_address) {
+		bufmgr_gem->exec2_objects[index].flags |=
+			EXEC_OBJECT_SUPPORTS_48B_ADDRESS;
+	}
 	bufmgr_gem->exec_count++;
 }
 
@@ -1925,11 +1943,33 @@ do_bo_emit_reloc(drm_intel_bo *bo, uint32_t offset,
 	else
 		bo_gem->reloc_target_info[bo_gem->reloc_count].flags = 0;
 
+	if (target_bo_gem->supports_48b_address)
+		bo_gem->reloc_target_info[bo_gem->reloc_count].flags |=
+			DRM_INTEL_RELOC_SUPPORTS_48B_ADDRESS;
+
 	bo_gem->reloc_count++;
 
 	return 0;
 }
 
+static void drm_intel_gem_bo_set_supports_48b_address(drm_intel_bo *bo)
+{
+	drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
+	drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
+
+	if (bufmgr_gem->gen >= 8)
+		bo_gem->supports_48b_address = 1;
+}
+
+static void drm_intel_gem_bo_clear_supports_48b_address(drm_intel_bo *bo)
+{
+	drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
+	drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
+
+	if (bufmgr_gem->gen >= 8)
+		bo_gem->supports_48b_address = 0;
+}
+
 static int
 drm_intel_gem_bo_emit_reloc(drm_intel_bo *bo, uint32_t offset,
 			    drm_intel_bo *target_bo, uint32_t target_offset,
@@ -2043,7 +2083,7 @@ drm_intel_gem_bo_process_reloc2(drm_intel_bo *bo)
 
 	for (i = 0; i < bo_gem->reloc_count; i++) {
 		drm_intel_bo *target_bo = bo_gem->reloc_target_info[i].bo;
-		int need_fence;
+		int need_fence, supports_48b_addr;
 
 		if (target_bo == bo)
 			continue;
@@ -2056,8 +2096,12 @@ drm_intel_gem_bo_process_reloc2(drm_intel_bo *bo)
 		need_fence = (bo_gem->reloc_target_info[i].flags &
 			      DRM_INTEL_RELOC_FENCE);
 
+		supports_48b_addr = (bo_gem->reloc_target_info[i].flags &
+				    DRM_INTEL_RELOC_SUPPORTS_48B_ADDRESS);
+
 		/* Add the target to the validate list */
-		drm_intel_add_validate_buffer2(target_bo, need_fence);
+		drm_intel_add_validate_buffer2(target_bo, need_fence,
+					       supports_48b_addr);
 	}
 }
 
@@ -2217,7 +2261,7 @@ do_exec2(drm_intel_bo *bo, int used, drm_intel_context *ctx,
 	/* Add the batch buffer to the validation list.  There are no relocations
 	 * pointing to it.
 	 */
-	drm_intel_add_validate_buffer2(bo, 0);
+	drm_intel_add_validate_buffer2(bo, 0, 0);
 
 	memclear(execbuf);
 	execbuf.buffers_ptr = (uintptr_t)bufmgr_gem->exec2_objects;
@@ -3299,6 +3343,8 @@ drm_intel_bufmgr_gem_init(int fd, int batch_size)
 	bufmgr_gem->bufmgr.bo_wait_rendering = drm_intel_gem_bo_wait_rendering;
 	bufmgr_gem->bufmgr.bo_emit_reloc = drm_intel_gem_bo_emit_reloc;
 	bufmgr_gem->bufmgr.bo_emit_reloc_fence = drm_intel_gem_bo_emit_reloc_fence;
+	bufmgr_gem->bufmgr.bo_set_supports_48b_address = drm_intel_gem_bo_set_supports_48b_address;
+	bufmgr_gem->bufmgr.bo_clear_supports_48b_address = drm_intel_gem_bo_clear_supports_48b_address;
 	bufmgr_gem->bufmgr.bo_pin = drm_intel_gem_bo_pin;
 	bufmgr_gem->bufmgr.bo_unpin = drm_intel_gem_bo_unpin;
 	bufmgr_gem->bufmgr.bo_get_tiling = drm_intel_gem_bo_get_tiling;
diff --git a/intel/intel_bufmgr_priv.h b/intel/intel_bufmgr_priv.h
index 59ebd18..774fa02 100644
--- a/intel/intel_bufmgr_priv.h
+++ b/intel/intel_bufmgr_priv.h
@@ -152,6 +152,17 @@ struct _drm_intel_bufmgr {
 	void (*destroy) (drm_intel_bufmgr *bufmgr);
 
 	/**
+	 * Set/Clear 48-bit address support flag in a given bo.
+	 *
+	 * Any resource used with flat/heapless (0x00000000-0xfffff000)
+	 * General State Heap (GSH) or Intructions State Heap (ISH) must
+	 * be in a 32-bit range. 48-bit range will only be used when explicitly
+	 * requested.
+	 */
+	void (*bo_set_supports_48b_address) (drm_intel_bo *bo);
+	void (*bo_clear_supports_48b_address) (drm_intel_bo *bo);
+
+	/**
 	 * Add relocation entry in reloc_buf, which will be updated with the
 	 * target buffer's real offset on on command submission.
 	 *
-- 
2.5.0



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