kernel-ark/include/asm-x86_64/smp.h
Eric W. Biederman 3d483f4757 [PATCH] Fix sync_tsc hang
sync_tsc was using smp_call_function to ask the boot processor to report
it's tsc value.  smp_call_function performs an IPI_send_allbutself which is
a broadcast ipi.  There is a window during processor startup during which
the target cpu has started and before it has initialized it's interrupt
vectors so it can properly process an interrupt.  Receveing an interrupt
during that window will triple fault the cpu and do other nasty things.

Why cli does not protect us from that is beyond me.

The simple fix is to match ia64 and provide a smp_call_function_single.
Which avoids the broadcast and is more efficient.

This certainly fixes the problem of getting stuck on boot which was
very easy to trigger on my SMP Hyperthreaded Xeon, and I think
it fixes it for the right reasons.

Minor changes by AK

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-29 15:01:13 -07:00

139 lines
3.0 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/threads.h>
#include <linux/cpumask.h>
#include <linux/bitops.h>
extern int disable_apic;
#endif
#ifdef CONFIG_X86_LOCAL_APIC
#ifndef __ASSEMBLY__
#include <asm/fixmap.h>
#include <asm/mpspec.h>
#ifdef CONFIG_X86_IO_APIC
#include <asm/io_apic.h>
#endif
#include <asm/apic.h>
#include <asm/thread_info.h>
#endif
#endif
#ifdef CONFIG_SMP
#ifndef ASSEMBLY
#include <asm/pda.h>
struct pt_regs;
extern cpumask_t cpu_present_mask;
extern cpumask_t cpu_possible_map;
extern cpumask_t cpu_online_map;
extern cpumask_t cpu_callout_map;
/*
* Private routines/data
*/
extern void smp_alloc_memory(void);
extern volatile unsigned long smp_invalidate_needed;
extern int pic_mode;
extern void lock_ipi_call_lock(void);
extern void unlock_ipi_call_lock(void);
extern int smp_num_siblings;
extern void smp_send_reschedule(int cpu);
extern void zap_low_mappings(void);
void smp_stop_cpu(void);
extern int smp_call_function_single(int cpuid, void (*func) (void *info),
void *info, int retry, int wait);
extern cpumask_t cpu_sibling_map[NR_CPUS];
extern cpumask_t cpu_core_map[NR_CPUS];
extern u8 phys_proc_id[NR_CPUS];
extern u8 cpu_core_id[NR_CPUS];
#define SMP_TRAMPOLINE_BASE 0x6000
/*
* On x86 all CPUs are mapped 1:1 to the APIC space.
* This simplifies scheduling and IPI sending and
* compresses data structures.
*/
static inline int num_booting_cpus(void)
{
return cpus_weight(cpu_callout_map);
}
#define raw_smp_processor_id() read_pda(cpunumber)
extern __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 safe_smp_processor_id(void);
extern int __cpu_disable(void);
extern void __cpu_die(unsigned int cpu);
#endif /* !ASSEMBLY */
#define NO_PROC_ID 0xFF /* No processor magic marker */
#endif
#ifndef ASSEMBLY
/*
* Some lowlevel functions might want to know about
* the real APIC ID <-> CPU # mapping.
*/
extern u8 x86_cpu_to_apicid[NR_CPUS]; /* physical ID */
extern u8 x86_cpu_to_log_apicid[NR_CPUS];
extern u8 bios_cpu_apicid[];
static inline unsigned int cpu_mask_to_apicid(cpumask_t cpumask)
{
return cpus_addr(cpumask)[0];
}
static inline int cpu_present_to_apicid(int mps_cpu)
{
if (mps_cpu < NR_CPUS)
return (int)bios_cpu_apicid[mps_cpu];
else
return BAD_APICID;
}
#endif /* !ASSEMBLY */
#ifndef CONFIG_SMP
#define stack_smp_processor_id() 0
#define safe_smp_processor_id() 0
#define cpu_logical_map(x) (x)
#else
#include <asm/thread_info.h>
#define stack_smp_processor_id() \
({ \
struct thread_info *ti; \
__asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (CURRENT_MASK)); \
ti->cpu; \
})
#endif
#ifndef __ASSEMBLY__
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
#endif