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]>
---
diff -urNp linux-2.6.21-rc5-orig/include/asm-x86_64/smp.h
linux-2.6.21-rc5/include/asm-x86_64/smp.h
--- linux-2.6.21-rc5-orig/include/asm-x86_64/smp.h 2007-04-04
15:57:31.000000000 +0900
+++ linux-2.6.21-rc5/include/asm-x86_64/smp.h 2007-04-04 16:25:52.000000000
+0900
@@ -59,12 +59,6 @@ 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);
@@ -73,10 +67,14 @@ extern unsigned __cpuinitdata disabled_c
#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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