[PATCH 2/2] arch/irq: Centralise no_irq_type

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Having no_irq_type defined per arch, but using common callbacks is a mess, and
particualrly hard to bootstrap a new architecture with.

Now that the ack()/end() hooks have been exported suitably, move the
definition of no_irq_type into common/irq.c, and into .rodata for good
measure.

No functional change, but a whole lot less tangled.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Julien Grall <julien@xxxxxxx>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
CC: Bertrand Marquis <bertrand.marquis@xxxxxxx>
CC: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
CC: Shawn Anastasio <sanastasio@xxxxxxxxxxxxxxxxxxxxx>

Oleksii: For RISC-V, you should only need to provide a irq_ack_none() stub now.
---
 xen/arch/arm/irq.c    | 10 ----------
 xen/arch/ppc/stubs.c  |  9 ---------
 xen/arch/x86/irq.c    |  9 ---------
 xen/common/irq.c      | 13 +++++++++++++
 xen/include/xen/irq.h |  2 +-
 5 files changed, 14 insertions(+), 29 deletions(-)

diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
index 7138f9e7c283..e5fb26a3de2d 100644
--- a/xen/arch/arm/irq.c
+++ b/xen/arch/arm/irq.c
@@ -45,16 +45,6 @@ void irq_end_none(struct irq_desc *irq)
     gic_hw_ops->gic_host_irq_type->end(irq);
 }
 
-hw_irq_controller no_irq_type = {
-    .typename = "none",
-    .startup = irq_startup_none,
-    .shutdown = irq_shutdown_none,
-    .enable = irq_enable_none,
-    .disable = irq_disable_none,
-    .ack = irq_ack_none,
-    .end = irq_end_none
-};
-
 static irq_desc_t irq_desc[NR_IRQS];
 static DEFINE_PER_CPU(irq_desc_t[NR_LOCAL_IRQS], local_irq_desc);
 
diff --git a/xen/arch/ppc/stubs.c b/xen/arch/ppc/stubs.c
index 4e03428e071a..923f0e7b2095 100644
--- a/xen/arch/ppc/stubs.c
+++ b/xen/arch/ppc/stubs.c
@@ -139,15 +139,6 @@ void irq_ack_none(struct irq_desc *desc)
     BUG_ON("unimplemented");
 }
 
-hw_irq_controller no_irq_type = {
-    .typename = "none",
-    .startup = irq_startup_none,
-    .shutdown = irq_shutdown_none,
-    .enable = irq_enable_none,
-    .disable = irq_disable_none,
-    .ack = irq_ack_none,
-};
-
 int arch_init_one_irq_desc(struct irq_desc *desc)
 {
     BUG_ON("unimplemented");
diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index cfd7a08479d2..e36e06deaa68 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -472,15 +472,6 @@ void cf_check irq_ack_none(struct irq_desc *desc)
     ack_bad_irq(desc->irq);
 }
 
-hw_irq_controller no_irq_type = {
-    "none",
-    irq_startup_none,
-    irq_shutdown_none,
-    irq_enable_none,
-    irq_disable_none,
-    irq_ack_none,
-};
-
 static vmask_t *irq_get_used_vector_mask(int irq)
 {
     vmask_t *ret = NULL;
diff --git a/xen/common/irq.c b/xen/common/irq.c
index 7225b4637486..29729349a6f2 100644
--- a/xen/common/irq.c
+++ b/xen/common/irq.c
@@ -3,6 +3,19 @@
 
 DEFINE_PER_CPU(const struct cpu_user_regs *, irq_regs);
 
+const hw_irq_controller no_irq_type = {
+    .typename  = "none",
+    .startup   = irq_startup_none,
+    .shutdown  = irq_shutdown_none,
+    .enable    = irq_enable_none,
+    .disable   = irq_disable_none,
+    .ack       = irq_ack_none,
+
+#ifdef irq_end_none /* Hook is optional per arch */
+    .end       = irq_end_none,
+#endif
+};
+
 int init_one_irq_desc(struct irq_desc *desc)
 {
     int err;
diff --git a/xen/include/xen/irq.h b/xen/include/xen/irq.h
index b71f65db8621..327cd2217c7e 100644
--- a/xen/include/xen/irq.h
+++ b/xen/include/xen/irq.h
@@ -122,7 +122,7 @@ extern int request_irq(unsigned int irq, unsigned int 
irqflags,
                void (*handler)(int irq, void *dev_id),
                const char *devname, void *dev_id);
 
-extern hw_irq_controller no_irq_type;
+extern const hw_irq_controller no_irq_type;
 void cf_check no_action(int cpl, void *dev_id);
 unsigned int cf_check irq_startup_none(struct irq_desc *desc);
 void cf_check irq_actor_none(struct irq_desc *desc);
-- 
2.30.2