mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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67664c8f7e
This patch introduces a startup parameter no_broadcast. When we enable CONFIG_HOTPLUG_CPU, we dont want to use broadcast shortcut as it has ill effects on a offline cpu. If we issue broadcast, the IPI is also delivered to offline cpus, or partially up cpu causing stale IPI's to be handled, which is a problem and can cause undesirable effects. Introduces a new startup cmdline option no_ipi_broadcast, that can be switched at cmdline if necessary. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Acked-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
54 lines
1.1 KiB
C
54 lines
1.1 KiB
C
#ifndef __ASM_MACH_IPI_H
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#define __ASM_MACH_IPI_H
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void send_IPI_mask_bitmask(cpumask_t mask, int vector);
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void __send_IPI_shortcut(unsigned int shortcut, int vector);
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extern int no_broadcast;
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static inline void send_IPI_mask(cpumask_t mask, int vector)
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{
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send_IPI_mask_bitmask(mask, vector);
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}
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static inline void __local_send_IPI_allbutself(int vector)
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{
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if (no_broadcast) {
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cpumask_t mask = cpu_online_map;
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int this_cpu = get_cpu();
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cpu_clear(this_cpu, mask);
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send_IPI_mask(mask, vector);
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put_cpu();
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} else
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__send_IPI_shortcut(APIC_DEST_ALLBUT, vector);
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}
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static inline void __local_send_IPI_all(int vector)
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{
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if (no_broadcast)
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send_IPI_mask(cpu_online_map, vector);
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else
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__send_IPI_shortcut(APIC_DEST_ALLINC, vector);
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}
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static inline void send_IPI_allbutself(int vector)
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{
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/*
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* if there are no other CPUs in the system then we get an APIC send
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* error if we try to broadcast, thus avoid sending IPIs in this case.
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*/
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if (!(num_online_cpus() > 1))
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return;
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__local_send_IPI_allbutself(vector);
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return;
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}
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static inline void send_IPI_all(int vector)
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{
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__local_send_IPI_all(vector);
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}
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#endif /* __ASM_MACH_IPI_H */
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