Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=dd988528f4a7d64908b427c251d727f3c3e88add
Commit: dd988528f4a7d64908b427c251d727f3c3e88add
Parent: a36166c6ef45081fea6eeaf5ca785d7ed786b6e2
Author: Fernando Luis Vazquez Cao <[EMAIL PROTECTED]>
AuthorDate: Wed May 9 02:33:28 2007 -0700
Committer: Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Wed May 9 12:30:48 2007 -0700
Use the APIC to determine the hardware processor id - x86_64
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 <[EMAIL PROTECTED]>
Cc: "Luck, Tony" <[EMAIL PROTECTED]>
Acked-by: Andi Kleen <[EMAIL PROTECTED]>
Cc: "Eric W. Biederman" <[EMAIL PROTECTED]>
Cc: Vivek Goyal <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
include/asm-x86_64/smp.h | 14 ++++++--------
1 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/include/asm-x86_64/smp.h b/include/asm-x86_64/smp.h
index f62fda5..3f303d2 100644
--- a/include/asm-x86_64/smp.h
+++ b/include/asm-x86_64/smp.h
@@ -57,12 +57,6 @@ static inline int num_booting_cpus(void)
#define raw_smp_processor_id() read_pda(cpunumber)
-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 int *)(APIC_BASE+APIC_ID));
-}
-
extern int __cpu_disable(void);
extern void __cpu_die(unsigned int cpu);
extern void prefill_possible_map(void);
@@ -71,10 +65,14 @@ extern unsigned __cpuinitdata disabled_cpus;
#define NO_PROC_ID 0xFF /* No processor magic marker */
-#else /* CONFIG_SMP */
-#define hard_smp_processor_id() 0
#endif /* CONFIG_SMP */
+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 int *)(APIC_BASE+APIC_ID));
+}
+
/*
* Some lowlevel functions might want to know about
* the real APIC ID <-> CPU # mapping.
-
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