[PATCH for-4.20 2/2] x86/irq: drop fixup_irqs() parameters

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

The solely remaining caller always passes the same globally available
parameters.  Drop the parameters and modify fixup_irqs() to use
cpu_online_map in place of the input mask parameter, and always be verbose
in its output printing.

While there remove some of the checks given the single context where
fixup_irqs() is now called, which should always be in the CPU offline path,
after the CPU going offline has been removed from cpu_online_map.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
There's more cleanup that can likely be done here, but it's best if such
cleanup is done after the cpu_mask and old_cpu_mask irq_desc fields are
converted from cpu masks to integers, as logic delivery mode should never
be used for external interrupts now.
---
 xen/arch/x86/include/asm/irq.h |  4 ++--
 xen/arch/x86/irq.c             | 30 +++++++++++++-----------------
 xen/arch/x86/smpboot.c         |  2 +-
 3 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/xen/arch/x86/include/asm/irq.h b/xen/arch/x86/include/asm/irq.h
index d3bc76806808..354868ba31ab 100644
--- a/xen/arch/x86/include/asm/irq.h
+++ b/xen/arch/x86/include/asm/irq.h
@@ -168,8 +168,8 @@ void free_domain_pirqs(struct domain *d);
 int map_domain_emuirq_pirq(struct domain *d, int pirq, int emuirq);
 int unmap_domain_pirq_emuirq(struct domain *d, int pirq);
 
-/* Evacuate interrupts assigned to CPUs not present in the input CPU mask. */
-void fixup_irqs(const cpumask_t *mask, bool verbose);
+/* Evacuate interrupts assigned to CPUs not present in the CPU online map. */
+void fixup_irqs(void);
 void fixup_eoi(void);
 
 int  init_irq_data(void);
diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index e56bacc88d84..ff3ac832f4b9 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -2590,17 +2590,21 @@ static int __init cf_check setup_dump_irqs(void)
 }
 __initcall(setup_dump_irqs);
 
-/* Evacuate interrupts assigned to CPUs not present in the input CPU mask. */
-void fixup_irqs(const cpumask_t *mask, bool verbose)
+/* Evacuate interrupts assigned to CPUs not present in the CPU online map. */
+void fixup_irqs(void)
 {
+    const unsigned int cpu = smp_processor_id();
     unsigned int irq;
     static int warned;
     struct irq_desc *desc;
 
+    /* Only to be called from the context of a CPU going offline. */
+    ASSERT(!cpu_online(cpu));
+
     for ( irq = 0; irq < nr_irqs; irq++ )
     {
         bool break_affinity = false, set_affinity = true, check_irr = false;
-        unsigned int vector, cpu = smp_processor_id();
+        unsigned int vector;
         cpumask_t *affinity = this_cpu(scratch_cpumask);
 
         if ( irq == 2 )
@@ -2644,12 +2648,6 @@ void fixup_irqs(const cpumask_t *mask, bool verbose)
         }
 
         if ( desc->arch.move_in_progress &&
-             /*
-              * Only attempt to adjust the mask if the current CPU is going
-              * offline, otherwise the whole system is going down and leaving
-              * stale data in the masks is fine.
-              */
-             !cpu_online(cpu) &&
              cpumask_test_cpu(cpu, desc->arch.old_cpu_mask) )
         {
             /*
@@ -2691,16 +2689,17 @@ void fixup_irqs(const cpumask_t *mask, bool verbose)
 
         /*
          * Avoid shuffling the interrupt around as long as current target CPUs
-         * are a subset of the input mask.  What fixup_irqs() cares about is
-         * evacuating interrupts from CPUs not in the input mask.
+         * are a subset of the online mask.  What fixup_irqs() cares about is
+         * evacuating interrupts from CPUs not in the online mask.
          */
-        if ( !desc->action || cpumask_subset(desc->arch.cpu_mask, mask) )
+        if ( !desc->action || cpumask_subset(desc->arch.cpu_mask,
+                                             &cpu_online_map) )
         {
             spin_unlock(&desc->lock);
             continue;
         }
 
-        if ( !cpumask_intersects(mask, desc->affinity) )
+        if ( !cpumask_intersects(&cpu_online_map, desc->affinity) )
         {
             break_affinity = true;
             cpumask_setall(affinity);
@@ -2716,7 +2715,7 @@ void fixup_irqs(const cpumask_t *mask, bool verbose)
          * the interrupt, signal to check whether there are any pending vectors
          * to be handled in the local APIC after the interrupt has been moved.
          */
-        if ( !cpu_online(cpu) && cpumask_test_cpu(cpu, desc->arch.cpu_mask) )
+        if ( cpumask_test_cpu(cpu, desc->arch.cpu_mask) )
             check_irr = true;
 
         if ( desc->handler->set_affinity )
@@ -2743,9 +2742,6 @@ void fixup_irqs(const cpumask_t *mask, bool verbose)
 
         spin_unlock(&desc->lock);
 
-        if ( !verbose )
-            continue;
-
         if ( !set_affinity )
             printk("Cannot set affinity for IRQ%u\n", irq);
         else if ( break_affinity )
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index 79a79c54c304..891a29fca146 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -1282,7 +1282,7 @@ void __cpu_disable(void)
 
     /* It's now safe to remove this processor from the online map */
     cpumask_clear_cpu(cpu, &cpu_online_map);
-    fixup_irqs(&cpu_online_map, 1);
+    fixup_irqs();
     fixup_eoi();
 }
 
-- 
2.46.0