fpga: zynqmp: support loading authenticated images

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

Based on solution by Jorge Ramirez-Ortiz <jorge@foundries.io>

Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@foundries.io>
Tested-by: Ricardo Salveti <ricardo@foundries.io>
Link: https://lore.kernel.org/r/20220722141614.297383-13-oleksandr.suvorov@foundries.io
Signed-off-by: Michal Simek <michal.simek@amd.com>

boot/Kconfig

@@ -210,8 +210,8 @@ 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.
 

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

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>
@@ -202,9 +203,12 @@ static int zynqmp_validate_bitstream(xilinx_desc *desc, const void *buf,
 #if CONFIG_IS_ENABLED(FPGA_LOAD_SECURE)
 static int zynqmp_check_compatible(xilinx_desc *desc, int flags)
 {
-	/* If no flags set, the image is legacy */
+	/*
+	 * If no flags set, the image may be legacy, but we need to
+	 * signal caller this situation with specific error code.
+	 */
 	if (!flags)
-		return 0;
+		return -ENODATA;
 
 	/* For legacy bitstream images no need for other methods exist */
 	if ((flags & desc->flags) && flags == FPGA_LEGACY)
@@ -217,7 +221,7 @@ static int zynqmp_check_compatible(xilinx_desc *desc, int flags)
 	if (desc->operations->loads && (flags & desc->flags))
 		return 0;
 
-	return FPGA_FAIL;
+	return -ENODEV;
 }
 #endif
 
@@ -231,8 +235,9 @@ static int zynqmp_load(xilinx_desc *desc, const void *buf, size_t bsize,
 	u32 buf_lo, buf_hi;
 	u32 bsize_req = (u32)bsize;
 	u32 ret_payload[PAYLOAD_ARG_CNT];
-
 #if CONFIG_IS_ENABLED(FPGA_LOAD_SECURE)
+	struct fpga_secure_info info = { 0 };
+
 	ret = zynqmp_check_compatible(desc, flags);
 	if (ret) {
 		if (ret != -ENODATA) {
@@ -242,6 +247,21 @@ static int zynqmp_load(xilinx_desc *desc, const void *buf, size_t bsize,
 		/* If flags is not set, the image treats as legacy */
 		flags = FPGA_LEGACY;
 	}
+
+	switch (flags) {
+	case FPGA_LEGACY:
+		break;	/* Handle the legacy image later in this function */
+#if CONFIG_IS_ENABLED(FPGA_LOAD_SECURE)
+	case FPGA_XILINX_ZYNQMP_DDRAUTH:
+		/* DDR authentication */
+		info.authflag = ZYNQMP_FPGA_AUTH_DDR;
+		info.encflag = FPGA_NO_ENC_OR_NO_AUTH;
+		return desc->operations->loads(desc, buf, bsize, &info);
+#endif
+	default:
+		printf("Unsupported bitstream type %d\n", flags);
+		return FPGA_FAIL;
+	}
 #endif
 
 	if (zynqmp_firmware_version() <= PMUFW_V1_0) {
@@ -337,7 +357,10 @@ static int __maybe_unused zynqmp_str2flag(xilinx_desc *desc, const char *str)
 {
 	if (!strncmp(str, "u-boot,fpga-legacy", 18))
 		return FPGA_LEGACY;
-
+#if CONFIG_IS_ENABLED(FPGA_LOAD_SECURE)
+	if (!strncmp(str, "u-boot,zynqmp-fpga-ddrauth", 26))
+		return FPGA_XILINX_ZYNQMP_DDRAUTH;
+#endif
 	return 0;
 }
 

include/xilinx.h

@@ -39,6 +39,7 @@ typedef enum {			/* typedef xilinx_family */
 
 /* FPGA bitstream supported types */
 #define FPGA_LEGACY			BIT(0)
+#define FPGA_XILINX_ZYNQMP_DDRAUTH	BIT(1)
 
 typedef struct {		/* typedef xilinx_desc */
 	xilinx_family family;	/* part type */

include/zynqmppl.h

@@ -25,6 +25,10 @@
 
 extern struct xilinx_fpga_op zynqmp_op;
 
+#if CONFIG_IS_ENABLED(FPGA_LOAD_SECURE)
+#define ZYNQMP_FPGA_FLAGS	(FPGA_LEGACY | FPGA_XILINX_ZYNQMP_DDRAUTH)
+#else
 #define ZYNQMP_FPGA_FLAGS	(FPGA_LEGACY)
+#endif
 
 #endif /* _ZYNQMPPL_H_ */