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Message-Id: <200905181458.39429.bjorn.helgaas@hp.com>
Date: Mon, 18 May 2009 14:58:37 -0600
From: Bjorn Helgaas <bjorn.helgaas@...com>
To: Yinghai Lu <yinghai@...nel.org>
Cc: Ingo Molnar <mingo@...e.hu>, Thomas Gleixner <tglx@...utronix.de>,
"H. Peter Anvin" <hpa@...or.com>,
Jesse Barnes <jbarnes@...tuousgeek.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
linux-pci@...r.kernel.org, Len Brown <lenb@...nel.org>
Subject: Re: [PATCH, v2] x86: add X86_UPDATE_MPTABLE option
On Monday 18 May 2009 11:59:57 am Yinghai Lu wrote:
>
> so could enable it for special purpose.
> 1. for acpi enabled kernel kexec kernel without acpi
> 2. for crossing check mptable or have correct mptable
>
> even with this option enabled, user still need to use
> update_mpatble or alloc_mptable in command line
>
> v2: update to make it depends on KEXEC according to Bjorn
Wait a minute. I did raise the possibility of a config option,
but only in the context of code whose only purpose was to help
debug the BIOS. And I suggested that code like that might not
belong in the mainline at all.
But this code is not like that, since you apparently need it for
kexec in general. I don't think you should add an additional
config option just for this code. A new option would just add
complexity for no benefit.
Bjorn
> esp system have several cards and there is bridge in those cards
> [ Impact: new config option to disable update_mptable ]
>
> Signed-off-by: Yinghai Lu <yinghai@...nel.org>
> Cc: Bjorn Helgaas <bjorn.helgaas@...com>
> Cc: Jesse Barnes <jbarnes@...tuousgeek.org>
> Cc: Len Brown <lenb@...nel.org>
>
> ---
> arch/x86/Kconfig | 10 ++++++++++
> arch/x86/include/asm/mpspec.h | 6 +++---
> arch/x86/kernel/acpi/boot.c | 3 ++-
> arch/x86/kernel/mpparse.c | 4 ++++
> 4 files changed, 19 insertions(+), 4 deletions(-)
>
> Index: linux-2.6/arch/x86/Kconfig
> ===================================================================
> --- linux-2.6.orig/arch/x86/Kconfig
> +++ linux-2.6/arch/x86/Kconfig
> @@ -292,6 +292,16 @@ config X86_MPPARSE
> For old smp systems that do not have proper acpi support. Newer systems
> (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
>
> +config X86_UPDATE_MPTABLE
> + bool "Enable update mptable according to ACPI"
> + default n
> + depends on X86_MPPARSE && ACPI && KEXEC
> + ---help---
> + Some systems do not have correct mptable. With "update_mptable" or
> + "alloc_mptable" kernel could try to update mptable according to DSDT.
> + Then could use kexec to start second kernel (even old) without ACPI
> + support compiled in or "acpi=off"
> +
> config X86_BIGSMP
> bool "Support for big SMP systems with more than 8 CPUs"
> depends on X86_32 && SMP
> Index: linux-2.6/arch/x86/kernel/acpi/boot.c
> ===================================================================
> --- linux-2.6.orig/arch/x86/kernel/acpi/boot.c
> +++ linux-2.6/arch/x86/kernel/acpi/boot.c
> @@ -1159,7 +1159,7 @@ void __init mp_config_acpi_legacy_irqs(v
> static int mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
> int polarity)
> {
> -#ifdef CONFIG_X86_MPPARSE
> +#ifdef CONFIG_X86_UPDATE_MPTABLE
> struct mpc_intsrc mp_irq;
> struct pci_dev *pdev;
> unsigned char number;
> @@ -1191,6 +1191,7 @@ static int mp_config_acpi_gsi(struct dev
>
> save_mp_irq(&mp_irq);
> #endif
> +
> return 0;
> }
>
> Index: linux-2.6/arch/x86/kernel/mpparse.c
> ===================================================================
> --- linux-2.6.orig/arch/x86/kernel/mpparse.c
> +++ linux-2.6/arch/x86/kernel/mpparse.c
> @@ -797,6 +797,8 @@ void __init find_smp_config(void)
> __find_smp_config(1);
> }
>
> +#ifdef CONFIG_X86_UPDATE_MPTABLE
> +
> #ifdef CONFIG_X86_IO_APIC
> static u8 __initdata irq_used[MAX_IRQ_SOURCES];
>
> @@ -1080,3 +1082,5 @@ static int __init update_mp_table(void)
> }
>
> late_initcall(update_mp_table);
> +
> +#endif /* CONFIG_X86_UPDATE_MPTABLE */
> Index: linux-2.6/arch/x86/include/asm/mpspec.h
> ===================================================================
> --- linux-2.6.orig/arch/x86/include/asm/mpspec.h
> +++ linux-2.6/arch/x86/include/asm/mpspec.h
> @@ -60,10 +60,8 @@ extern void get_smp_config(void);
>
> #ifdef CONFIG_X86_MPPARSE
> extern void find_smp_config(void);
> -extern void early_reserve_e820_mpc_new(void);
> #else
> static inline void find_smp_config(void) { }
> -static inline void early_reserve_e820_mpc_new(void) { }
> #endif
>
> void __cpuinit generic_processor_info(int apicid, int version);
> @@ -87,13 +85,15 @@ static inline int acpi_probe_gsi(void)
> }
> #endif /* CONFIG_ACPI */
>
> -#ifdef CONFIG_X86_MPPARSE
> +#ifdef CONFIG_X86_UPDATE_MPTABLE
> extern int enable_update_mptable;
> +extern void early_reserve_e820_mpc_new(void);
> #else
> static inline int enable_update_mptable(void)
> {
> return 0;
> }
> +static inline void early_reserve_e820_mpc_new(void) { }
> #endif
>
> #define PHYSID_ARRAY_SIZE BITS_TO_LONGS(MAX_APICS)
>
--
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