Messages in this thread | | | Date | Thu, 5 Jun 2014 16:33:53 +0100 | From | Mark Rutland <> | Subject | Re: [PATCH] ARM64:DMI: Add smbios/dmi support on arm64 |
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On Wed, Jun 04, 2014 at 04:01:36PM +0100, Yi Li wrote: > Hi Mark, > > Please see the comments below: > > On Wednesday, June 04, 2014 09:32 PM, Mark Rutland wrote: > > On Tue, Jun 03, 2014 at 04:57:13PM +0100, Yi Li wrote: > >> Add smbios/dmi support on arm64 system, it depends on > >> EFI boot. > > And what exactly does this provide us with? > > > > What is exposed through SMBIOS/DMI, and why would I want to enable it? > Yi: SMBIOS/DMI is one basic spec/feature for server product(like x86 and > IA64). > Many OEMs/ODMs hope to use ARM64 as server's processor. > So we need to support SMBIOS on ARM64. > > SMBIOS mainly describes some hardware and software information for > the system, like BIOS information > CPU information, Memory information ,and so on. please refer to > http://www.dmtf.org/standards/smbios
What information does it provide that is useful that we cannot get from elsewhere?
What use case is enabled by having this support, other than being able to tick a box that we have a feature we might not even need?
> > > > >> Signed-off-by: Yi Li <yi.li@linaro.org> > >> --- > >> > >> Changes since v1: > >> -Followed Ard Biesheuvel's suggestion to rebase the patch on > >> Matt Fleming's arm64-efi branch. > >> > >> arch/arm64/Kconfig | 10 ++++++++++ > >> arch/arm64/include/asm/dmi.h | 28 ++++++++++++++++++++++++++++ > >> arch/arm64/kernel/setup.c | 2 ++ > >> 3 files changed, 40 insertions(+) > >> create mode 100644 arch/arm64/include/asm/dmi.h > >> > >> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > >> index 6c71f12..13ee261 100644 > >> --- a/arch/arm64/Kconfig > >> +++ b/arch/arm64/Kconfig > >> @@ -294,6 +294,16 @@ 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. > >> endmenu > >> > >> menu "Userspace binary formats" > >> diff --git a/arch/arm64/include/asm/dmi.h b/arch/arm64/include/asm/dmi.h > >> new file mode 100644 > >> index 0000000..f2198bf > >> --- /dev/null > >> +++ b/arch/arm64/include/asm/dmi.h > >> @@ -0,0 +1,28 @@ > >> +/* > >> + * arch/arm64/include/asm/dmi.h > >> + * > >> + * Copyright (C) 2013 Linaro Limited. > >> + * Written by: Yi Li (yi.li@linaro.org) > >> + * > >> + * based on arch/ia64/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 1 > >> + > >> +#include <linux/slab.h> > >> +#include <asm/io.h> > > Shouldn't that be linux/efi.h? > > > > Why do we need asm/io.h? > Yi: porting it from IA64 , so the io.h is not needed exactly! > but slab.h is must included ,not efi.h (tested by compiling)
Below you refer to efi_lookup_mapped_addr, which (as far as I can tell) is defined in efi.h. You might be getting lucky with users of dmi_early_remap and dmi_remap having already incldued efi.h, but you shouldn't rely on it.
If you make use of something, you should include the header that defines it.
Cheers, Mark.
> >> + > >> +/* Use efi mappings for DMI */ > >> +#define dmi_early_remap(x, l) efi_lookup_mapped_addr(x) > >> +#define dmi_early_unmap(x, l) > >> +#define dmi_remap(x, l) efi_lookup_mapped_addr(x) > >> +#define dmi_unmap(x) > >> +#define dmi_alloc(l) kzalloc(l, GFP_ATOMIC) > >> + > >> +#endif > > None of these seem to use anything from io.h directly. > Yi: You are right , io.h doesn't need. > > Cheers, > > Mark. > >
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