arm64: Add SMC and HVC commands

This patch adds smc and hvc commands, that allow issuing Secure Monitor
Calls and Hypervisor Calls conforming to the ARM SMC Calling Convention.

Add Kconfig items to allow each command can be individually enabled.

Signed-off-by: Michalis Pappas <mpappas@fastmail.fm>
Reviewed-by: Simon Glass <sjg@chromium.org>

cmd/Kconfig

@@ -1445,6 +1445,20 @@ config CMD_HASH
 	  saved to memory or to an environment variable. It is also possible
 	  to verify a hash against data in memory.
 
+config CMD_HVC
+	bool "Support the 'hvc' command"
+	depends on ARM_SMCCC
+	help
+	  Allows issuing Hypervisor Calls (HVCs). Mostly useful for
+	  development and testing.
+
+config CMD_SMC
+	bool "Support the 'smc' command"
+	depends on ARM_SMCCC
+	help
+	  Allows issuing Secure Monitor Calls (SMCs). Mostly useful for
+	  development and testing.
+
 config HASH_VERIFY
 	bool "hash -v"
 	depends on CMD_HASH

cmd/Makefile

@@ -60,6 +60,7 @@ obj-$(CONFIG_CMD_FS_GENERIC) += fs.o
 obj-$(CONFIG_CMD_FUSE) += fuse.o
 obj-$(CONFIG_CMD_GETTIME) += gettime.o
 obj-$(CONFIG_CMD_GPIO) += gpio.o
+obj-$(CONFIG_CMD_HVC) += smccc.o
 obj-$(CONFIG_CMD_I2C) += i2c.o
 obj-$(CONFIG_CMD_IOTRACE) += iotrace.o
 obj-$(CONFIG_CMD_HASH) += hash.o
@@ -112,6 +113,7 @@ obj-$(CONFIG_CMD_SHA1SUM) += sha1sum.o
 obj-$(CONFIG_CMD_SETEXPR) += setexpr.o
 obj-$(CONFIG_CMD_SPI) += spi.o
 obj-$(CONFIG_CMD_STRINGS) += strings.o
+obj-$(CONFIG_CMD_SMC) += smccc.o
 obj-$(CONFIG_CMD_TERMINAL) += terminal.o
 obj-$(CONFIG_CMD_TIME) += time.o
 obj-$(CONFIG_CMD_TRACE) += trace.o

cmd/smccc.c

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018
+ * Michalis Pappas <mpappas@fastmail.fm>
+ */
+#include <asm/psci.h>
+#include <common.h>
+#include <command.h>
+#include <linux/arm-smccc.h>
+#include <linux/compiler.h>
+#include <linux/psci.h>
+
+static int do_call(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	struct arm_smccc_res res;
+
+	unsigned long fid;
+
+	unsigned long a1;
+	unsigned long a2;
+	unsigned long a3;
+	unsigned long a4;
+	unsigned long a5;
+	unsigned long a6;
+	unsigned long a7;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	fid = simple_strtoul(argv[1], NULL, 16);
+
+	a1 = argc > 2 ? simple_strtoul(argv[2], NULL, 16) : 0;
+	a2 = argc > 3 ? simple_strtoul(argv[3], NULL, 16) : 0;
+	a3 = argc > 4 ? simple_strtoul(argv[4], NULL, 16) : 0;
+	a4 = argc > 5 ? simple_strtoul(argv[5], NULL, 16) : 0;
+	a5 = argc > 6 ? simple_strtoul(argv[6], NULL, 16) : 0;
+	a6 = argc > 7 ? simple_strtoul(argv[7], NULL, 16) : 0;
+	a7 = argc > 8 ? simple_strtoul(argv[8], NULL, 16) : 0;
+
+	if (!strcmp(argv[0], "smc"))
+		arm_smccc_smc(fid, a1, a2, a3, a4, a5, a6, a7, &res);
+	else
+		arm_smccc_hvc(fid, a1, a2, a3, a4, a5, a6, a7, &res);
+
+	printf("Res:  %ld %ld %ld %ld\n", res.a0, res.a1, res.a2, res.a3);
+
+	return 0;
+}
+
+#ifdef CONFIG_CMD_SMC
+U_BOOT_CMD(
+	smc,	8,		2,	do_call,
+	"Issue a Secure Monitor Call",
+	"<fid> [arg1 ... arg6] [id]\n"
+	"  - fid Function ID\n"
+	"  - arg SMC arguments, passed to X1-X6 (default to zero)\n"
+	"  - id  Secure OS ID / Session ID, passed to W7 (defaults to zero)\n"
+);
+#endif
+
+#ifdef CONFIG_CMD_HVC
+U_BOOT_CMD(
+	hvc,	8,		2,	do_call,
+	"Issue a Hypervisor Call",
+	"<fid> [arg1...arg7] [id]\n"
+	"  - fid Function ID\n"
+	"  - arg HVC arguments, passed to X1-X6 (default to zero)\n"
+	"  - id  Session ID, passed to W7 (defaults to zero)\n"
+);
+#endif
+