From cb987d4822d38f8540b7cd580c33628858d38120 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 31 Dec 2015 16:30:47 +0000 Subject: [PATCH] x86/irq: Reorganize the search in assign_irq_vector commit 95ffeb4b5baca266e1d0d2bc90f1513e6f419cdd upstream. Split out the code which advances the target cpu for the search so we can reuse it for the next patch which adds an early validation check for the vectormask which we get from the apic. Add comments while at it. Signed-off-by: Thomas Gleixner Tested-by: Borislav Petkov Tested-by: Joe Lawrence Cc: Jiang Liu Cc: Jeremiah Mahler Cc: andy.shevchenko@gmail.com Cc: Guenter Roeck Link: http://lkml.kernel.org/r/20151231160106.484562040@linutronix.de Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/apic/vector.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index 74f7dd6f69b1..60bab79abbe5 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -155,14 +155,9 @@ next: vector = FIRST_EXTERNAL_VECTOR + offset; } - if (unlikely(current_vector == vector)) { - cpumask_or(searched_cpumask, searched_cpumask, - vector_cpumask); - cpumask_andnot(vector_cpumask, mask, searched_cpumask); - cpu = cpumask_first_and(vector_cpumask, - cpu_online_mask); - continue; - } + /* If the search wrapped around, try the next cpu */ + if (unlikely(current_vector == vector)) + goto next_cpu; if (test_bit(vector, used_vectors)) goto next; @@ -184,6 +179,19 @@ next: d->cfg.vector = vector; cpumask_copy(d->domain, vector_cpumask); goto success; + +next_cpu: + /* + * We exclude the current @vector_cpumask from the requested + * @mask and try again with the next online cpu in the + * result. We cannot modify @mask, so we use @vector_cpumask + * as a temporary buffer here as it will be reassigned when + * calling apic->vector_allocation_domain() above. + */ + cpumask_or(searched_cpumask, searched_cpumask, vector_cpumask); + cpumask_andnot(vector_cpumask, mask, searched_cpumask); + cpu = cpumask_first_and(vector_cpumask, cpu_online_mask); + continue; } return -ENOSPC; -- 2.34.1