The patch titled
Use the APIC to determine the hardware processor id - i386
has been added to the -mm tree. Its filename is
use-the-apic-to-determine-the-hardware-processor-id-i386.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Use the APIC to determine the hardware processor id - i386
From: Fernando Luis Vazquez Cao <fernando@xxxxxxxxxxxxx>
hard_smp_processor_id used to be just a macro that hard-coded
hard_smp_processor_id to 0 in the non SMP case. When booting non SMP kernels
on hardware where the boot ioapic id is not 0 this turns out to be a problem.
This is happens frequently in the case of kdump and once in a great while in
the case of real hardware.
Use the APIC to determine the hardware processor id in both UP and SMP kernels
to fix this issue.
Notice that hard_smp_processor_id is only used by SMP code or by code that
works with apics so we do not need to handle the case when apics are not
present and hard_smp_processor_id should never be called there.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@xxxxxxxxxxxxx>
Cc: "Luck, Tony" <tony.luck@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/i386/mach-generic/probe.c | 2 -
include/asm-i386/smp.h | 36 ++++++++++++++++++-------------
2 files changed, 21 insertions(+), 17 deletions(-)
diff -puN arch/i386/mach-generic/probe.c~use-the-apic-to-determine-the-hardware-processor-id-i386 arch/i386/mach-generic/probe.c
--- a/arch/i386/mach-generic/probe.c~use-the-apic-to-determine-the-hardware-processor-id-i386
+++ a/arch/i386/mach-generic/probe.c
@@ -119,9 +119,7 @@ int __init acpi_madt_oem_check(char *oem
return 0;
}
-#ifdef CONFIG_SMP
int hard_smp_processor_id(void)
{
return genapic->get_apic_id(*(unsigned long *)(APIC_BASE+APIC_ID));
}
-#endif
diff -puN include/asm-i386/smp.h~use-the-apic-to-determine-the-hardware-processor-id-i386 include/asm-i386/smp.h
--- a/include/asm-i386/smp.h~use-the-apic-to-determine-the-hardware-processor-id-i386
+++ a/include/asm-i386/smp.h
@@ -124,20 +124,6 @@ static inline int num_booting_cpus(void)
return cpus_weight(cpu_callout_map);
}
-#ifdef CONFIG_X86_LOCAL_APIC
-
-#ifdef APIC_DEFINITION
-extern int hard_smp_processor_id(void);
-#else
-#include <mach_apicdef.h>
-static inline int hard_smp_processor_id(void)
-{
- /* we don't want to mark this access volatile - bad code generation */
- return GET_APIC_ID(*(unsigned long *)(APIC_BASE+APIC_ID));
-}
-#endif
-#endif
-
extern int safe_smp_processor_id(void);
extern int __cpu_disable(void);
extern void __cpu_die(unsigned int cpu);
@@ -147,7 +133,6 @@ extern unsigned int num_processors;
#else /* CONFIG_SMP */
-#define hard_smp_processor_id() 0
#define safe_smp_processor_id() 0
#define cpu_physical_id(cpu) boot_cpu_physical_apicid
@@ -157,6 +142,27 @@ extern unsigned int num_processors;
#ifndef __ASSEMBLY__
+#ifdef CONFIG_X86_LOCAL_APIC
+
+#ifdef APIC_DEFINITION
+extern int hard_smp_processor_id(void);
+#else
+#include <mach_apicdef.h>
+static inline int hard_smp_processor_id(void)
+{
+ /* we don't want to mark this access volatile - bad code generation */
+ return GET_APIC_ID(*(unsigned long *)(APIC_BASE+APIC_ID));
+}
+#endif /* APIC_DEFINITION */
+
+#else /* CONFIG_X86_LOCAL_APIC */
+
+#ifndef CONFIG_SMP
+#define hard_smp_processor_id() 0
+#endif
+
+#endif /* CONFIG_X86_LOCAL_APIC */
+
extern u8 apicid_2_node[];
#ifdef CONFIG_X86_LOCAL_APIC
_
Patches currently in -mm which might be from fernando@xxxxxxxxxxxxx are
remove-hardcoding-of-hard_smp_processor_id-on-up.patch
use-the-apic-to-determine-the-hardware-processor-id-i386.patch
use-the-apic-to-determine-the-hardware-processor-id-x86_64.patch
always-ask-the-hardware-to-obtain-hardware-processor-id-ia64.patch
-
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