IRQ: u16 is too narrow for an event channel number

FIFO event channels allow ports up to 2^17, so we need to use a wider
field in struct pirq. Move "masked" such that it may share the 8-byte
slot with struct arch_pirq on 64-bit arches, rather than leaving a
7-byte hole in all cases.

Take the opportunity and also add a comment regarding "arch" placement
within the structure.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Arm: fix build after 892b9dcebdb7

"IRQ: u16 is too narrow for an event channel number" introduced a use of
evetchn_port_t, but its typedef apparently surfaces indirectly here only
on x86.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 892b9dcebdb7f646657e11cfdd95a385107bbefa
master date: 2020-01-14 12:03:47 +0100
master commit: b4194711ffaffa5e63d986338fb8d4020fa6bad1
master date: 2020-01-14 16:06:27 +0100

diff --git a/xen/include/xen/irq.h b/xen/include/xen/irq.h
index 586b78393abd950c7c4950b7b62c1c827b4523c8..ce2752428192edc86372a565d033bc6db1184b79 100644 (file)
--- a/xen/include/xen/irq.h
+++ b/xen/include/xen/irq.h
@@ -8,6 +8,7 @@
 #include <xen/list.h>
 #include <asm/regs.h>
 #include <asm/hardirq.h>
+#include <public/event_channel.h>
 
 struct irqaction {
     void (*handler)(int, void *, struct cpu_user_regs *);
@@ -127,9 +128,10 @@ struct vcpu;
 
 struct pirq {
     int pirq;
-    u16 evtchn;
-    bool_t masked;
+    evtchn_port_t evtchn;
     struct rcu_head rcu_head;
+    bool masked;
+    /* Architectures may require this field to be last. */
     struct arch_pirq arch;
 };