[3/6] x86/setup: init nr_irqs after having detected x2APIC support

Commit Message

Roger Pau Monné June 23, 2022, 8:24 a.m. UTC

Logic in ioapic_init() that sets the number of available vectors for
external interrupts requires knowing the x2APIC Destination Mode.  As
such move the call after x2APIC BSP setup.

Do it as part of init_irq_data(), which is called just after x2APIC
BSP init and also makes use of nr_irqs itself.

No functional change intended.

Signed-off-by: Roger Pau Monné <[e-mail]>
---
 xen/arch/x86/io_apic.c | 10 ----------
 xen/arch/x86/irq.c     | 10 ++++++++++
 2 files changed, 10 insertions(+), 10 deletions(-)

Patch

diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c
index c086f40f63..8d4923ba9a 100644
--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -2653,16 +2653,6 @@  void __init ioapic_init(void)
                max_gsi_irqs, nr_irqs_gsi);
         nr_irqs_gsi = max_gsi_irqs;
     }
-
-    if ( nr_irqs == 0 )
-        nr_irqs = cpu_has_apic ?
-                  max(0U + num_present_cpus() * NR_DYNAMIC_VECTORS,
-                      8 * nr_irqs_gsi) :
-                  nr_irqs_gsi;
-    else if ( nr_irqs < 16 )
-        nr_irqs = 16;
-    printk(XENLOG_INFO "IRQ limits: %u GSI, %u MSI/MSI-X\n",
-           nr_irqs_gsi, nr_irqs - nr_irqs_gsi);
 }
 
 unsigned int arch_hwdom_irqs(domid_t domid)
diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index de30ee7779..b51e25f696 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -420,6 +420,16 @@  int __init init_irq_data(void)
     struct irq_desc *desc;
     int irq, vector;
 
+    if ( nr_irqs == 0 )
+        nr_irqs = cpu_has_apic ? max(0U + num_present_cpus() *
+                                     NR_DYNAMIC_VECTORS, 8 * nr_irqs_gsi)
+                               : nr_irqs_gsi;
+    else if ( nr_irqs < 16 )
+        nr_irqs = 16;
+
+    printk(XENLOG_INFO "IRQ limits: %u GSI, %u MSI/MSI-X\n",
+           nr_irqs_gsi, nr_irqs - nr_irqs_gsi);
+
     for ( vector = 0; vector < X86_NR_VECTORS; ++vector )
         this_cpu(vector_irq)[vector] = INT_MIN;