linux/include/asm-i386/smp.h
Zwane Mwaikambo 4ad8d38342 [PATCH] i386 boottime for_each_cpu broken
for_each_cpu walks through all processors in cpu_possible_map, which is
defined as cpu_callout_map on i386 and isn't initialised until all
processors have been booted. This breaks things which do for_each_cpu
iterations early during boot. So, define cpu_possible_map as a bitmap with
NR_CPUS bits populated. This was triggered by a patch i'm working on which
does alloc_percpu before bringing up secondary processors.

From: Alexander Nyberg <alexn@telia.com>

i386-boottime-for_each_cpu-broken.patch
i386-boottime-for_each_cpu-broken-fix.patch

The SMP version of __alloc_percpu checks the cpu_possible_map before
allocating memory for a certain cpu.  With the above patches the BSP cpuid
is never set in cpu_possible_map which breaks CONFIG_SMP on uniprocessor
machines (as soon as someone tries to dereference something allocated via
__alloc_percpu, which in fact is never allocated since the cpu is not set
in cpu_possible_map).

Signed-off-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Alexander Nyberg <alexn@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:13 -07:00

99 lines
2.2 KiB
C

#ifndef __ASM_SMP_H
#define __ASM_SMP_H
/*
* We need the APIC definitions automatically as part of 'smp.h'
*/
#ifndef __ASSEMBLY__
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/cpumask.h>
#endif
#ifdef CONFIG_X86_LOCAL_APIC
#ifndef __ASSEMBLY__
#include <asm/fixmap.h>
#include <asm/bitops.h>
#include <asm/mpspec.h>
#ifdef CONFIG_X86_IO_APIC
#include <asm/io_apic.h>
#endif
#include <asm/apic.h>
#endif
#endif
#define BAD_APICID 0xFFu
#ifdef CONFIG_SMP
#ifndef __ASSEMBLY__
/*
* Private routines/data
*/
extern void smp_alloc_memory(void);
extern int pic_mode;
extern int smp_num_siblings;
extern cpumask_t cpu_sibling_map[];
extern cpumask_t cpu_core_map[];
extern void (*mtrr_hook) (void);
extern void zap_low_mappings (void);
extern void lock_ipi_call_lock(void);
extern void unlock_ipi_call_lock(void);
#define MAX_APICID 256
extern u8 x86_cpu_to_apicid[];
#ifdef CONFIG_HOTPLUG_CPU
extern void cpu_exit_clear(void);
extern void cpu_uninit(void);
#endif
/*
* This function is needed by all SMP systems. It must _always_ be valid
* from the initial startup. We map APIC_BASE very early in page_setup(),
* so this is correct in the x86 case.
*/
#define raw_smp_processor_id() (current_thread_info()->cpu)
extern cpumask_t cpu_callout_map;
extern cpumask_t cpu_callin_map;
extern cpumask_t cpu_possible_map;
/* We don't mark CPUs online until __cpu_up(), so we need another measure */
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
static __inline int logical_smp_processor_id(void)
{
/* we don't want to mark this access volatile - bad code generation */
return GET_APIC_LOGICAL_ID(*(unsigned long *)(APIC_BASE+APIC_LDR));
}
#endif
extern int __cpu_disable(void);
extern void __cpu_die(unsigned int cpu);
#endif /* !__ASSEMBLY__ */
#define NO_PROC_ID 0xFF /* No processor magic marker */
#endif
#endif