[PATCH 1/1] cmd: provide command sbi

[Heinrich Schuchardt]

Provide a command to display information about the SBI implementation.

The output might look like:

=> sbi
SBI 0.2
OpenSBI
Extensions:
  sbi_set_timer
  sbi_console_putchar
  sbi_console_getchar
  sbi_clear_ipi
  sbi_send_ipi
  sbi_remote_fence_i
  sbi_remote_sfence_vma
  sbi_remote_sfence_vma_asid
  sbi_shutdown
  SBI Base Functionality
  Timer Extension
  IPI Extension
  RFENCE Extension
  Hart State Management Extension

The command can be used to construct a unit test checking that the
communication with the SEE is working.

Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
 arch/riscv/include/asm/sbi.h |  2 +
 arch/riscv/lib/sbi.c         | 36 ++++++++++++++++
 cmd/Kconfig                  |  6 +++
 cmd/riscv/Makefile           |  1 +
 cmd/riscv/sbi.c              | 80 ++++++++++++++++++++++++++++++++++++
 5 files changed, 125 insertions(+)
 create mode 100644 cmd/riscv/sbi.c

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 08e1ac0c0e..53ca316180 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -115,6 +115,8 @@ void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
 				unsigned long asid);
 #endif
 void sbi_set_timer(uint64_t stime_value);
+long sbi_get_spec_version(void);
+int sbi_get_impl_id(void);
 int sbi_probe_extension(int ext);

 #endif
diff --git a/arch/riscv/lib/sbi.c b/arch/riscv/lib/sbi.c
index 8fbc23839d..920889ed13 100644
--- a/arch/riscv/lib/sbi.c
+++ b/arch/riscv/lib/sbi.c
@@ -53,6 +53,42 @@ void sbi_set_timer(uint64_t stime_value)
 #endif
 }

+/**
+ * sbi_get_spec_version() - get current SBI specification version
+ *
+ * Return: version id
+ */
+long sbi_get_spec_version(void)
+{
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_SPEC_VERSION,
+			0, 0, 0, 0, 0, 0);
+	if (!ret.error)
+		if (ret.value)
+			return ret.value;
+
+	return -ENOTSUPP;
+}
+
+/**
+ * sbi_get_impl_id() - get SBI implemenation ID
+ *
+ * Return: implementation ID
+ */
+int sbi_get_impl_id(void)
+{
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_IMP_ID,
+			0, 0, 0, 0, 0, 0);
+	if (!ret.error)
+		if (ret.value)
+			return ret.value;
+
+	return -ENOTSUPP;
+}
+
 /**
  * sbi_probe_extension() - Check if an SBI extension ID is supported or not.
  * @extid: The extension ID to be probed.
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 23d7e27dc8..7a9fab51c5 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -270,6 +270,12 @@ config SPL_CMD_TLV_EEPROM
 	help
 	  Read system EEPROM data block in ONIE Tlvinfo format from SPL.

+config CMD_SBI
+	bool "SBI information"
+	depends on RISCV_SMODE
+	help
+	  Display information about the SBI implementation.
+
 endmenu

 menu "Boot commands"
diff --git a/cmd/riscv/Makefile b/cmd/riscv/Makefile
index 24df023ece..1e6ac364e3 100644
--- a/cmd/riscv/Makefile
+++ b/cmd/riscv/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0+

 obj-$(CONFIG_CMD_EXCEPTION) += exception.o
+obj-$(CONFIG_CMD_SBI) += sbi.o
diff --git a/cmd/riscv/sbi.c b/cmd/riscv/sbi.c
new file mode 100644
index 0000000000..559d950ffb
--- /dev/null
+++ b/cmd/riscv/sbi.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * The 'sbi' command displays information about the SBI implementation.
+ *
+ * Copyright (c) 2020, Heinrich Schuchardt <xypron.glpk at gmx.de>
+ */
+
+#include <common.h>
+#include <command.h>
+#include <asm/sbi.h>
+
+struct sbi_ext {
+	const u32 id;
+	const char *name;
+};
+
+static struct sbi_ext extensions[] = {
+	{ 0x00000000, "sbi_set_timer" },
+	{ 0x00000001, "sbi_console_putchar" },
+	{ 0x00000002, "sbi_console_getchar" },
+	{ 0x00000003, "sbi_clear_ipi" },
+	{ 0x00000004, "sbi_send_ipi" },
+	{ 0x00000005, "sbi_remote_fence_i" },
+	{ 0x00000006, "sbi_remote_sfence_vma" },
+	{ 0x00000007, "sbi_remote_sfence_vma_asid" },
+	{ 0x00000008, "sbi_shutdown" },
+	{ 0x00000010, "SBI Base Functionality" },
+	{ 0x54494D45, "Timer Extension" },
+	{ 0x00735049, "IPI Extension" },
+	{ 0x52464E43, "RFENCE Extension" },
+	{ 0x0048534D, "Hart State Management Extension" },
+};
+
+static int do_sbi(struct cmd_tbl *cmdtp, int flag, int argc,
+		  char *const argv[])
+{
+	int i;
+	long ret;
+
+	ret = sbi_get_spec_version();
+	if (ret >= 0)
+		printf("SBI %ld.%ld\n", ret >> 24, ret &0xffffff);
+	ret = sbi_get_impl_id();
+	if (ret >= 0) {
+		switch (ret) {
+		case 0:
+			printf("Berkeley Boot Loader (BBL)\n");
+			break;
+		case 1:
+			printf("OpenSBI\n");
+			break;
+		case 2:
+			printf("Xvisor\n");
+			break;
+		case 3:
+			printf("KVM\n");
+			break;
+		default:
+			printf("Unknown implementation\n");
+			break;
+		}
+	}
+	printf("Extensions:\n");
+	for (i = 0; i < ARRAY_SIZE(extensions); ++i) {
+		ret = sbi_probe_extension(extensions[i].id);
+		if (ret > 0)
+			printf("  %s\n", extensions[i].name);
+	}
+	return 0;
+}
+
+#ifdef CONFIG_SYS_LONGHELP
+static char sbi_help_text[] = "";
+#endif
+
+U_BOOT_CMD_COMPLETE(
+	sbi, 2, 0, do_sbi,
+	"display SBI information",
+	sbi_help_text, NULL
+);
--
2.28.0