[PATCH v2] riscv: dmi: Add SMBIOS/DMI support

From: Haibo Xu
Date: Sun Mar 17 2024 - 21:55:44 EST


Enable the dmi driver for riscv which would allow access the
SMBIOS info through some userspace file(/sys/firmware/dmi/*).

The change was based on that of arm64 and has been verified
by dmidecode tool.

Signed-off-by: Haibo Xu <haibo1.xu@xxxxxxxxx>
---
Changes since v1
- Change to use memremap/memunmap for dmi_(early)_remap/unmap
definition(suggested by Ard)
- Minor clean up for comments (Ard)
---
arch/riscv/Kconfig | 11 +++++++++++
arch/riscv/include/asm/dmi.h | 24 ++++++++++++++++++++++++
drivers/firmware/efi/riscv-runtime.c | 13 +++++++++++++
3 files changed, 48 insertions(+)
create mode 100644 arch/riscv/include/asm/dmi.h

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 8ebafe337eac..3639151cb4ef 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -952,6 +952,17 @@ config EFI
allow the kernel to be booted as an EFI application. This
is only useful on systems that have UEFI firmware.

+config DMI
+ bool "Enable support for SMBIOS (DMI) tables"
+ depends on EFI
+ default y
+ help
+ This enables SMBIOS/DMI feature for systems.
+
+ This option is only useful on systems that have UEFI firmware.
+ However, even with this option, the resultant kernel should
+ continue to boot on existing non-UEFI platforms.
+
config CC_HAVE_STACKPROTECTOR_TLS
def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0)

diff --git a/arch/riscv/include/asm/dmi.h b/arch/riscv/include/asm/dmi.h
new file mode 100644
index 000000000000..ca7cce557ef7
--- /dev/null
+++ b/arch/riscv/include/asm/dmi.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2024 Intel Corporation
+ *
+ * based on arch/arm64/include/asm/dmi.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef __ASM_DMI_H
+#define __ASM_DMI_H
+
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#define dmi_early_remap(x, l) memremap(x, l, MEMREMAP_WB)
+#define dmi_early_unmap(x, l) memunmap(x)
+#define dmi_remap(x, l) memremap(x, l, MEMREMAP_WB)
+#define dmi_unmap(x) memunmap(x)
+#define dmi_alloc(l) kzalloc(l, GFP_KERNEL)
+
+#endif
diff --git a/drivers/firmware/efi/riscv-runtime.c b/drivers/firmware/efi/riscv-runtime.c
index 09525fb5c240..c3bfb9e77e02 100644
--- a/drivers/firmware/efi/riscv-runtime.c
+++ b/drivers/firmware/efi/riscv-runtime.c
@@ -152,3 +152,16 @@ void arch_efi_call_virt_teardown(void)
{
efi_virtmap_unload();
}
+
+static int __init riscv_dmi_init(void)
+{
+ /*
+ * On riscv, DMI depends on UEFI, and dmi_setup() needs to
+ * be called early because dmi_id_init(), which is an arch_initcall
+ * itself, depends on dmi_scan_machine() having been called already.
+ */
+ dmi_setup();
+
+ return 0;
+}
+core_initcall(riscv_dmi_init);
--
2.34.1