ARMv8: add the secure monitor firmware framework

This framework is introduced for ARMv8 secure monitor mode firmware.
The main functions of the framework are, on EL3, verify the firmware,
load it to the secure memory and jump into it, and while it returned
to U-Boot, do some necessary setups at the 'target exception level'
that is determined by the respective secure firmware.

So far, the framework support only FIT format image, and need to define
the name of which config node should be used in 'configurations' and
the name of property for the raw secure firmware image in that config.
The FIT image should be stored in Byte accessing memory, such as NOR
Flash, or else it should be copied to main memory to use this framework.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>

3 files changed, 324 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv8/Makefile b/arch/arm/cpu/armv8/Makefile
index bf8644ccd2..ee9e0091a4 100644
--- a/arch/arm/cpu/armv8/Makefile
+++ b/arch/arm/cpu/armv8/Makefile
@@ -15,6 +15,7 @@ obj-y	+= cache.o
 obj-y	+= tlb.o
 obj-y	+= transition.o
 obj-y	+= fwcall.o
+obj-$(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT) += sec_firmware.o sec_firmware_asm.o
 
 obj-$(CONFIG_FSL_LAYERSCAPE) += fsl-layerscape/
 obj-$(CONFIG_S32V234) += s32v234/
diff --git a/arch/arm/cpu/armv8/sec_firmware.c b/arch/arm/cpu/armv8/sec_firmware.c
new file mode 100644
index 0000000000..e21e199381
--- /dev/null
+++ b/arch/arm/cpu/armv8/sec_firmware.c
@@ -0,0 +1,270 @@
+/*
+ * Copyright 2016 NXP Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <linux/kernel.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/types.h>
+#include <asm/macro.h>
+#include <asm/armv8/sec_firmware.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+extern void c_runtime_cpu_setup(void);
+
+#define SEC_FIRMWARE_LOADED	0x1
+#define SEC_FIRMWARE_RUNNING	0x2
+#define SEC_FIRMWARE_ADDR_MASK	(~0x3)
+	/*
+	 * Secure firmware load addr
+	 * Flags used: 0x1 secure firmware has been loaded to secure memory
+	 *             0x2 secure firmware is running
+	 */
+	phys_addr_t sec_firmware_addr;
+
+static int sec_firmware_get_data(const void *sec_firmware_img,
+				const void **data, size_t *size)
+{
+	int conf_node_off, fw_node_off;
+	char *conf_node_name = NULL;
+	char *desc;
+	int ret;
+
+	conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
+
+	conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
+	if (conf_node_off < 0) {
+		printf("SEC Firmware: %s: no such config\n", conf_node_name);
+		return -ENOENT;
+	}
+
+	fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
+			SEC_FIRMWARE_FIT_IMAGE);
+	if (fw_node_off < 0) {
+		printf("SEC Firmware: No '%s' in config\n",
+		       SEC_FIRMWARE_FIT_IMAGE);
+		return -ENOLINK;
+	}
+
+	/* Verify secure firmware image */
+	if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
+		printf("SEC Firmware: Bad firmware image (bad CRC)\n");
+		return -EINVAL;
+	}
+
+	if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
+		printf("SEC Firmware: Can't get %s subimage data/size",
+		       SEC_FIRMWARE_FIT_IMAGE);
+		return -ENOENT;
+	}
+
+	ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
+	if (ret)
+		printf("SEC Firmware: Can't get description\n");
+	else
+		printf("%s\n", desc);
+
+	return ret;
+}
+
+/*
+ * SEC Firmware FIT image parser checks if the image is in FIT
+ * format, verifies integrity of the image and calculates raw
+ * image address and size values.
+ *
+ * Returns 0 on success and a negative errno on error task fail.
+ */
+static int sec_firmware_parse_image(const void *sec_firmware_img,
+					const void **raw_image_addr,
+					size_t *raw_image_size)
+{
+	int ret;
+
+	ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
+					raw_image_size);
+	if (ret)
+		return ret;
+
+	debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
+	      *raw_image_addr, *raw_image_size);
+
+	return 0;
+}
+
+static int sec_firmware_copy_image(const char *title,
+			 u64 image_addr, u32 image_size, u64 sec_firmware)
+{
+	debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
+	memcpy((void *)sec_firmware, (void *)image_addr, image_size);
+	flush_dcache_range(sec_firmware, sec_firmware + image_size);
+
+	return 0;
+}
+
+/*
+ * This function will parse the SEC Firmware image, and then load it
+ * to secure memory.
+ */
+static int sec_firmware_load_image(const void *sec_firmware_img)
+{
+	const void *raw_image_addr;
+	size_t raw_image_size = 0;
+	int ret;
+
+	/*
+	 * The Excetpion Level must be EL3 to load and initialize
+	 * the SEC Firmware.
+	 */
+	if (current_el() != 3) {
+		ret = -EACCES;
+		goto out;
+	}
+
+#ifdef CONFIG_SYS_MEM_RESERVE_SECURE
+	/*
+	 * The SEC Firmware must be stored in secure memory.
+	 * Append SEC Firmware to secure mmu table.
+	 */
+	if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
+		ret = -ENXIO;
+		goto out;
+	}
+
+	sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
+			gd->arch.tlb_size;
+#else
+#error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
+#endif
+
+	/* Align SEC Firmware base address to 4K */
+	sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
+	debug("SEC Firmware: Load address: 0x%llx\n",
+	      sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
+
+	ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
+			&raw_image_size);
+	if (ret)
+		goto out;
+
+	/* TODO:
+	 * Check if the end addr of SEC Firmware has been extend the secure
+	 * memory.
+	 */
+
+	/* Copy the secure firmware to secure memory */
+	ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
+			raw_image_size, sec_firmware_addr &
+			SEC_FIRMWARE_ADDR_MASK);
+	if (ret)
+		goto out;
+
+	sec_firmware_addr |= SEC_FIRMWARE_LOADED;
+	debug("SEC Firmware: Entry point: 0x%llx\n",
+	      sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
+
+	return 0;
+
+out:
+	printf("SEC Firmware: error (%d)\n", ret);
+	sec_firmware_addr = 0;
+
+	return ret;
+}
+
+static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
+{
+	const void *entry = (void *)(sec_firmware_addr &
+				SEC_FIRMWARE_ADDR_MASK);
+
+	return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
+}
+
+/* Check the secure firmware FIT image */
+__weak bool sec_firmware_is_valid(const void *sec_firmware_img)
+{
+	if (fdt_check_header(sec_firmware_img)) {
+		printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
+		return false;
+	}
+
+	if (!fit_check_format(sec_firmware_img)) {
+		printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
+		return false;
+	}
+
+	return true;
+}
+
+#ifdef CONFIG_ARMV8_PSCI
+/*
+ * The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
+ * v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
+ * number will be returned according to SMC Calling Conventions. But
+ * when getting the NOT_SUPPORTED error number, we cannot ensure if
+ * the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
+ * won't be supported by this framework.
+ * And if the secure firmware isn't running, return NOT_SUPPORTED.
+ *
+ * The return value on success is PSCI version in format
+ * major[31:16]:minor[15:0].
+ */
+unsigned int sec_firmware_support_psci_version(void)
+{
+	if (sec_firmware_addr & SEC_FIRMWARE_RUNNING)
+		return _sec_firmware_support_psci_version();
+
+	return 0xffffffff;
+}
+#endif
+
+/*
+ * sec_firmware_init - Initialize the SEC Firmware
+ * @sec_firmware_img:	the SEC Firmware image address
+ * @eret_hold_l:	the address to hold exception return address low
+ * @eret_hold_h:	the address to hold exception return address high
+ */
+int sec_firmware_init(const void *sec_firmware_img,
+			u32 *eret_hold_l,
+			u32 *eret_hold_h)
+{
+	int ret;
+
+	if (!sec_firmware_is_valid(sec_firmware_img))
+		return -EINVAL;
+
+	ret = sec_firmware_load_image(sec_firmware_img);
+	if (ret) {
+		printf("SEC Firmware: Failed to load image\n");
+		return ret;
+	} else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
+		ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
+		if (ret) {
+			printf("SEC Firmware: Failed to initialize\n");
+			return ret;
+		}
+	}
+
+	debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
+	      current_el());
+
+	/*
+	 * The PE will be turned into target EL when returned from
+	 * SEC Firmware.
+	 */
+	if (current_el() != SEC_FIRMWARE_TARGET_EL)
+		return -EACCES;
+
+	sec_firmware_addr |= SEC_FIRMWARE_RUNNING;
+
+	/* Set exception table and enable caches if it isn't EL3 */
+	if (current_el() != 3) {
+		c_runtime_cpu_setup();
+		enable_caches();
+	}
+
+	return 0;
+}
diff --git a/arch/arm/cpu/armv8/sec_firmware_asm.S b/arch/arm/cpu/armv8/sec_firmware_asm.S
new file mode 100644
index 0000000000..0c6a46249a
--- /dev/null
+++ b/arch/arm/cpu/armv8/sec_firmware_asm.S
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2016 NXP Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <config.h>
+#include <linux/linkage.h>
+#include <asm/system.h>
+#include <asm/macro.h>
+
+WEAK(_sec_firmware_entry)
+	/*
+	 * x0: Secure Firmware entry point
+	 * x1: Exception return address Low
+	 * x2: Exception return address High
+	 */
+
+	/* Save stack pointer for EL2 */
+	mov	x3, sp
+	msr	sp_el2, x3
+
+	/* Set exception return address hold pointer */
+        adr	x4, 1f
+        mov	x3, x4
+#ifdef SEC_FIRMWARE_ERET_ADDR_REVERT
+        rev	w3, w3
+#endif
+        str	w3, [x1]
+        lsr	x3, x4, #32
+#ifdef SEC_FIRMWARE_ERET_ADDR_REVERT
+        rev	w3, w3
+#endif
+        str	w3, [x2]
+
+	/* Call SEC monitor */
+        br	x0
+
+1:
+        mov	x0, #0
+        ret
+ENDPROC(_sec_firmware_entry)
+
+#ifdef CONFIG_ARMV8_PSCI
+ENTRY(_sec_firmware_support_psci_version)
+	mov	x0, 0x84000000
+	mov	x1, 0x0
+	mov	x2, 0x0
+	mov	x3, 0x0
+	smc	#0
+	ret
+ENDPROC(_sec_firmware_support_psci_version)
+#endif