anv: move canonical_address calculation into a separate function

A later patch will make use of this in other places. Also, remove
dependency on undefined behavior of left-shifting a signed value.

v2: - move function into a separate header (Chris)
v3: (by Ken) Add new header to the various build systems.

Reviewed-by: Jordan Justen <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

2 files changed, 44 insertions, 0 deletions

diff --git a/src/intel/common/gen_gem.h b/src/intel/common/gen_gem.h
new file mode 100644
index 00000000000..842a455e050
--- /dev/null
+++ b/src/intel/common/gen_gem.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright © 2018 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef GEN_GEM_H
+#define GEN_GEM_H
+
+static inline uint64_t
+gen_canonical_address(uint64_t v)
+{
+   /* From the Broadwell PRM Vol. 2a, MI_LOAD_REGISTER_MEM::MemoryAddress:
+    *
+    *    "This field specifies the address of the memory location where the
+    *    register value specified in the DWord above will read from. The
+    *    address specifies the DWord location of the data. Range =
+    *    GraphicsVirtualAddress[63:2] for a DWord register GraphicsAddress
+    *    [63:48] are ignored by the HW and assumed to be in correct
+    *    canonical form [63:48] == [47]."
+    */
+   const int shift = 63 - 47;
+   return (int64_t)(v << shift) >> shift;
+}
+
+#endif /* GEN_GEM_H */
diff --git a/src/intel/common/meson.build b/src/intel/common/meson.build
index ebf69c05370..332e978b0ad 100644
--- a/src/intel/common/meson.build
+++ b/src/intel/common/meson.build
@@ -29,6 +29,7 @@ files_libintel_common = files(
   'gen_decoder.h',
   'gen_disasm.c',
   'gen_disasm.h',
+  'gen_gem.h',
   'gen_l3_config.c',
   'gen_l3_config.h',
   'gen_urb_config.c',