[RFC PATCH v4 6/6] fpga: zynqmp: support loading authenticated images

[Oleksandr Suvorov]

Add supporting new compatible string "u-boot,zynqmp-fpga-ddrauth" to
handle loading authenticated images (DDR).

Based on solution by Jorge Ramirez-Ortiz <jorge at foundries.io>
Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov at foundries.io>
Co-developed-by: Ricardo Salveti <ricardo at foundries.io>
Signed-off-by: Ricardo Salveti <ricardo at foundries.io>
Tested-by: Ricardo Salveti <ricardo at foundries.io>
---

Changes in v4:
- change interface to xilinx_desc->operations->open() callback.
- fix a bug from previous version of the patchset in dereferencing
  of a parent fpga_desc structure.

Changes in v3:
- remove the patch which introduced CMD_SPL_FPGA_LOAD_SECURE.
- fix mixing definitions/declarations.
- replace strcmp() calls with more secure strncmp().
- document the "u-boot,zynqmp-fpga-ddrauth" compatible string.
- fix code style by check-patch recommendations.

Changes in v2:
- add function fit_fpga_load() to simplify calls of fpga_load()
  from contexts without a compatible attribute.
- move all ZynqMP-specific logic to drivers/fpga/zynqmppl.c
- prepare for passing a "compatible" FDT property to any fpga driver.

 common/Kconfig.boot                   |  4 ++--
 doc/uImage.FIT/source_file_format.txt |  5 ++++-
 drivers/fpga/zynqmppl.c               | 21 +++++++++++++++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/common/Kconfig.boot b/common/Kconfig.boot
index a8d4be23a97..f8796541746 100644
--- a/common/Kconfig.boot
+++ b/common/Kconfig.boot
@@ -198,8 +198,8 @@ config SPL_LOAD_FIT
 	  1. "loadables" images, other than FDTs, which do not have a "load"
 	     property will not be loaded. This limitation also applies to FPGA
 	     images with the correct "compatible" string.
-	  2. For FPGA images, only the "compatible" = "u-boot,fpga-legacy"
-	     loading method is supported.
+	  2. For FPGA images, the supported "compatible" list is in the
+	     doc/uImage.FIT/source_file_format.txt.
 	  3. FDTs are only loaded for images with an "os" property of "u-boot".
 	     "linux" images are also supported with Falcon boot mode.
 
diff --git a/doc/uImage.FIT/source_file_format.txt b/doc/uImage.FIT/source_file_format.txt
index f93ac6d1c7b..461e2af2a84 100644
--- a/doc/uImage.FIT/source_file_format.txt
+++ b/doc/uImage.FIT/source_file_format.txt
@@ -184,7 +184,10 @@ the '/images' node should have the following layout:
     Mandatory for types: "firmware", and "kernel".
   - compatible : compatible method for loading image.
     Mandatory for types: "fpga", and images that do not specify a load address.
-    To use the generic fpga loading routine, use "u-boot,fpga-legacy".
+    Supported compatible methods:
+    "u-boot,fpga-legacy" - the generic fpga loading routine.
+    "u-boot,zynqmp-fpga-ddrauth" - signed non-encrypted FPGA bitstream for
+    Xilinx Zynq UltraScale+ (ZymqMP) device.
 
   Optional nodes:
   - hash-1 : Each hash sub-node represents separate hash or checksum
diff --git a/drivers/fpga/zynqmppl.c b/drivers/fpga/zynqmppl.c
index c7f9f4ae846..59948afa3ee 100644
--- a/drivers/fpga/zynqmppl.c
+++ b/drivers/fpga/zynqmppl.c
@@ -9,6 +9,7 @@
 #include <common.h>
 #include <compiler.h>
 #include <cpu_func.h>
+#include <fpga.h>
 #include <log.h>
 #include <zynqmppl.h>
 #include <zynqmp_firmware.h>
@@ -210,6 +211,26 @@ static int zynqmp_load(xilinx_desc **desc_ptr, const void *buf, size_t bsize,
 	u32 ret_payload[PAYLOAD_ARG_CNT];
 	bool xilfpga_old = false;
 	xilinx_desc *desc = *desc_ptr;
+	fpga_desc *fdesc = container_of((void *)desc_ptr, fpga_desc, devdesc);
+
+	if (fdesc && fdesc->compatible &&
+	    !strcmp(fdesc->compatible, "u-boot,zynqmp-fpga-ddrauth")) {
+#if CONFIG_IS_ENABLED(FPGA_LOAD_SECURE)
+		struct fpga_secure_info info = { 0 };
+
+		if (!desc->operations->loads) {
+			printf("%s: Missing load operation\n", __func__);
+			return FPGA_FAIL;
+		}
+		/* DDR authentication */
+		info.authflag = 1;
+		info.encflag = 2;
+		return desc->operations->loads(desc, buf, bsize, &info);
+#else
+		printf("No support for %s\n", fdesc->compatible);
+		return FPGA_FAIL;
+#endif
+	}
 
 	if (zynqmp_firmware_version() <= PMUFW_V1_0) {
 		puts("WARN: PMUFW v1.0 or less is detected\n");
-- 
2.31.1