arm: mach-k3: Add secure device support

K3 devices have High Security (HS) variants along with the non-HS already
supported. Like the previous generation devices (OMAP/Keystone2) K3
supports boot chain-of-trust by authenticating and optionally decrypting
images as they are unpacked from FIT images. Add support for this here.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Andreas Dannenberg <dannenberg@ti.com>

MAINTAINERS

@@ -733,6 +733,7 @@ S:	Supported
 F:	arch/arm/mach-omap2/omap5/sec_entry_cpu1.S
 F:	arch/arm/mach-omap2/sec-common.c
 F:	arch/arm/mach-omap2/config_secure.mk
+F:	arch/arm/mach-k3/security.c
 F:	configs/am335x_hs_evm_defconfig
 F:	configs/am335x_hs_evm_uart_defconfig
 F:	configs/am43xx_hs_evm_defconfig

arch/arm/Kconfig

@@ -1464,7 +1464,7 @@ endchoice
 
 config TI_SECURE_DEVICE
 	bool "HS Device Type Support"
-	depends on ARCH_KEYSTONE || ARCH_OMAP2PLUS
+	depends on ARCH_KEYSTONE || ARCH_OMAP2PLUS || ARCH_K3
 	help
 	  If a high secure (HS) device type is being used, this config
 	  must be set. This option impacts various aspects of the

arch/arm/mach-k3/Makefile

@@ -6,4 +6,5 @@
 obj-$(CONFIG_SOC_K3_AM6) += am6_init.o
 obj-$(CONFIG_ARM64) += arm64-mmu.o
 obj-$(CONFIG_CPU_V7R) += r5_mpu.o lowlevel_init.o
+obj-$(CONFIG_TI_SECURE_DEVICE) += security.o
 obj-y += common.o

arch/arm/mach-k3/security.c

@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * K3: Security functions
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <linux/soc/ti/ti_sci_protocol.h>
+#include <mach/spl.h>
+#include <spl.h>
+
+void board_fit_image_post_process(void **p_image, size_t *p_size)
+{
+	struct udevice *dev;
+	struct ti_sci_handle *ti_sci;
+	struct ti_sci_proc_ops *proc_ops;
+	u64 image_addr;
+	u32 image_size;
+	int ret;
+
+	/* Get handle to Device Management and Security Controller (SYSFW) */
+	ret = uclass_get_device_by_name(UCLASS_FIRMWARE, "dmsc", &dev);
+	if (ret) {
+		printf("Failed to get handle to SYSFW (%d)\n", ret);
+		hang();
+	}
+	ti_sci = (struct ti_sci_handle *)(ti_sci_get_handle_from_sysfw(dev));
+	proc_ops = &ti_sci->ops.proc_ops;
+
+	image_addr = (uintptr_t)*p_image;
+
+	debug("Authenticating image at address 0x%016llx\n", image_addr);
+
+	/* Authenticate image */
+	ret = proc_ops->proc_auth_boot_image(ti_sci, &image_addr, &image_size);
+	if (ret) {
+		printf("Authentication failed!\n");
+		hang();
+	}
+
+	/*
+	 * The image_size returned may be 0 when the authentication process has
+	 * moved the image. When this happens no further processing on the
+	 * image is needed or often even possible as it may have also been
+	 * placed behind a firewall when moved.
+	 */
+	*p_size = image_size;
+
+	/*
+	 * Output notification of successful authentication to re-assure the
+	 * user that the secure code is being processed as expected. However
+	 * suppress any such log output in case of building for SPL and booting
+	 * via YMODEM. This is done to avoid disturbing the YMODEM serial
+	 * protocol transactions.
+	 */
+	if (!(IS_ENABLED(CONFIG_SPL_BUILD) &&
+	      IS_ENABLED(CONFIG_SPL_YMODEM_SUPPORT) &&
+	      spl_boot_device() == BOOT_DEVICE_UART))
+		printf("Authentication passed\n");
+}