From a8ab26fe5bfeef43bdcde5182ca051ae0647607e Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sat, 16 Apr 2005 15:25:19 -0700 Subject: [PATCH] x86_64: Switch SMP bootup over to new CPU hotplug state machine This will allow hotplug CPU in the future and in general cleans up a lot of crufty code. It also should plug some races that the old hackish way introduces. Remove one old race workaround in NMI watchdog setup that is not needed anymore. I removed the old total sum of bogomips reporting code. The brag value of BogoMips has been greatly devalued in the last years on the open market. Real CPU hotplug will need some more work, but the infrastructure for it is there now. One drawback: the new TSC sync algorithm is less accurate than before. The old way of zeroing TSCs is too intrusive to do later. Instead the TSC of the BP is duplicated now, which is less accurate. akpm: - sync_tsc_bp_init seems to have the sense of `init' inverted. - SPIN_LOCK_UNLOCKED is deprecated - use DEFINE_SPINLOCK. Cc: Cc: Signed-off-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/smp.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'arch/x86_64/kernel/smp.c') diff --git a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c index e3cdbf9a88b..1e379ed17b1 100644 --- a/arch/x86_64/kernel/smp.c +++ b/arch/x86_64/kernel/smp.c @@ -27,6 +27,7 @@ #include #include #include +#include /* * Smarter SMP flushing macros. @@ -413,3 +414,27 @@ asmlinkage void smp_call_function_interrupt(void) atomic_inc(&call_data->finished); } } + +int safe_smp_processor_id(void) +{ + int apicid, i; + + if (disable_apic) + return 0; + + apicid = hard_smp_processor_id(); + if (x86_cpu_to_apicid[apicid] == apicid) + return apicid; + + for (i = 0; i < NR_CPUS; ++i) { + if (x86_cpu_to_apicid[i] == apicid) + return i; + } + + /* No entries in x86_cpu_to_apicid? Either no MPS|ACPI, + * or called too early. Either way, we must be CPU 0. */ + if (x86_cpu_to_apicid[0] == BAD_APICID) + return 0; + + return 0; /* Should not happen */ +} -- cgit v1.2.3