x86, irq: Protect __clear_irq_vector() with vector_lock

Function __clear_irq_vector() accesses vector related data structure,
so protect it with vector_lock. Also rename it as clear_irq_vector().

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1414397531-28254-8-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 4d871339ba4f658052024d1d387ddb94a0567243..ab8ca9327c06ddc213897b512fcde93dad97bd1b 100644 (file)
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1349,10 +1349,12 @@ int assign_irq_vector(int irq, struct irq_cfg *cfg, const struct cpumask *mask)
        return err;
 }
 
-static void __clear_irq_vector(int irq, struct irq_cfg *cfg)
+static void clear_irq_vector(int irq, struct irq_cfg *cfg)
 {
        int cpu, vector;
+       unsigned long flags;
 
+       raw_spin_lock_irqsave(&vector_lock, flags);
        BUG_ON(!cfg->vector);
 
        vector = cfg->vector;
@@ -1362,8 +1364,11 @@ static void __clear_irq_vector(int irq, struct irq_cfg *cfg)
        cfg->vector = 0;
        cpumask_clear(cfg->domain);
 
-       if (likely(!cfg->move_in_progress))
+       if (likely(!cfg->move_in_progress)) {
+               raw_spin_unlock_irqrestore(&vector_lock, flags);
                return;
+       }
+
        for_each_cpu_and(cpu, cfg->old_domain, cpu_online_mask) {
                for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
                        if (per_cpu(vector_irq, cpu)[vector] != irq)
@@ -1373,6 +1378,7 @@ static void __clear_irq_vector(int irq, struct irq_cfg *cfg)
                }
        }
        cfg->move_in_progress = 0;
+       raw_spin_unlock_irqrestore(&vector_lock, flags);
 }
 
 void __setup_vector_irq(int cpu)
@@ -1499,7 +1505,7 @@ static void setup_ioapic_irq(unsigned int irq, struct irq_cfg *cfg,
                                         &dest)) {
                pr_warn("Failed to obtain apicid for ioapic %d, pin %d\n",
                        mpc_ioapic_id(attr->ioapic), attr->ioapic_pin);
-               __clear_irq_vector(irq, cfg);
+               clear_irq_vector(irq, cfg);
 
                return;
        }
@@ -1513,7 +1519,7 @@ static void setup_ioapic_irq(unsigned int irq, struct irq_cfg *cfg,
        if (x86_io_apic_ops.setup_entry(irq, &entry, dest, cfg->vector, attr)) {
                pr_warn("Failed to setup ioapic entry for ioapic  %d, pin %d\n",
                        mpc_ioapic_id(attr->ioapic), attr->ioapic_pin);
-               __clear_irq_vector(irq, cfg);
+               clear_irq_vector(irq, cfg);
 
                return;
        }
@@ -3083,12 +3089,9 @@ int arch_setup_hwirq(unsigned int irq, int node)
 void arch_teardown_hwirq(unsigned int irq)
 {
        struct irq_cfg *cfg = irq_cfg(irq);
-       unsigned long flags;
 
        free_remapped_irq(irq);
-       raw_spin_lock_irqsave(&vector_lock, flags);
-       __clear_irq_vector(irq, cfg);
-       raw_spin_unlock_irqrestore(&vector_lock, flags);
+       clear_irq_vector(irq, cfg);
        free_irq_cfg(irq, cfg);
 }