eliminate remaining uses of struct irq_cfg

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -2279,7 +2279,6 @@ int ioapic_guest_write(unsigned long phy
     int apic, pin, irq, ret, vector, pirq;
     struct IO_APIC_route_entry rte = { 0 };
     unsigned long flags;
-    struct irq_cfg *cfg;
     struct irq_desc *desc;
 
     if ( (apic = ioapic_physbase_to_id(physbase)) < 0 )
@@ -2321,7 +2320,6 @@ int ioapic_guest_write(unsigned long phy
         return irq;
 
     desc = irq_to_desc(irq);
-    cfg = &desc->arch;
 
     /*
      * Since PHYSDEVOP_alloc_irq_vector is dummy, rte.vector is the pirq
@@ -2338,7 +2336,7 @@ int ioapic_guest_write(unsigned long phy
         spin_lock_irqsave(&ioapic_lock, flags);
         ret = io_apic_read(apic, 0x10 + 2 * pin);
         spin_unlock_irqrestore(&ioapic_lock, flags);
-        rte.vector = cfg->vector;
+        rte.vector = desc->arch.vector;
         if ( *(u32*)&rte != ret )
             WARN_BOGUS_WRITE("old_entry=%08x pirq=%d\n%s: "
                              "Attempt to modify IO-APIC pin for in-use IRQ!\n",
@@ -2346,7 +2344,7 @@ int ioapic_guest_write(unsigned long phy
         return 0;
     }
 
-    if ( cfg->vector <= 0 || cfg->vector > LAST_DYNAMIC_VECTOR ) {
+    if ( desc->arch.vector <= 0 || desc->arch.vector > LAST_DYNAMIC_VECTOR ) {
         vector = assign_irq_vector(irq);
         if ( vector < 0 )
             return vector;
@@ -2370,7 +2368,7 @@ int ioapic_guest_write(unsigned long phy
     /* Mask iff level triggered. */
     rte.mask = rte.trigger;
     /* Set the vector field to the real vector! */
-    rte.vector = cfg->vector;
+    rte.vector = desc->arch.vector;
 
     SET_DEST(rte.dest.dest32, rte.dest.logical.logical_dest,
              cpu_mask_to_apicid(desc->arch.cpu_mask));
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -285,16 +285,14 @@ void destroy_irq(unsigned int irq)
 int irq_to_vector(int irq)
 {
     int vector = -1;
-    struct irq_cfg *cfg;
 
     BUG_ON(irq >= nr_irqs || irq < 0);
 
     if (IO_APIC_IRQ(irq))
         vector = irq_vector[irq];
-    else if(MSI_IRQ(irq)) {
-        cfg = irq_cfg(irq);
-        vector = cfg->vector;
-    } else
+    else if (MSI_IRQ(irq))
+        vector = irq_to_desc(irq)->arch.vector;
+    else
         vector = LEGACY_VECTOR(irq);
 
     return vector;
--- a/xen/include/asm-ia64/linux-xen/asm/irq.h
+++ b/xen/include/asm-ia64/linux-xen/asm/irq.h
@@ -15,8 +15,7 @@
 #define NR_IRQS		256
 
 #ifdef XEN
-struct irq_cfg {
-#define arch_irq_desc irq_cfg
+struct arch_irq_desc {
         int  vector;
         cpumask_var_t cpu_mask;
 };
@@ -63,9 +62,6 @@ extern int request_irq_vector(unsigned i
 #define create_irq(x) assign_irq_vector(AUTO_ASSIGN_IRQ)
 #define destroy_irq(x) free_irq_vector(x)
 
-#define irq_cfg(x)        (&irq_desc[x].arch)
-#define irq_to_desc(x)    (&irq_desc[x]
-
 #define irq_complete_move(x) do {} \
     while(!x)
 
--- a/xen/include/asm-x86/irq.h
+++ b/xen/include/asm-x86/irq.h
@@ -20,17 +20,13 @@
 
 #define LEGACY_VECTOR(irq)          ((irq) + FIRST_LEGACY_VECTOR)
 
-#define irq_to_desc(irq)    (&irq_desc[irq])
-#define irq_cfg(irq)        (&irq_desc[irq].arch)
-
 typedef struct {
     DECLARE_BITMAP(_bits,NR_VECTORS);
 } vmask_t;
 
 struct irq_desc;
 
-struct irq_cfg {
-#define arch_irq_desc irq_cfg
+struct arch_irq_desc {
         s16 vector;                  /* vector itself is only 8 bits, */
         s16 old_vector;              /* but we use -1 for unassigned  */
         cpumask_var_t cpu_mask;
@@ -42,7 +38,7 @@ struct irq_cfg {
         s8 used;
 };
 
-/* For use with irq_cfg.used */
+/* For use with irq_desc.arch.used */
 #define IRQ_UNUSED      (0)
 #define IRQ_USED        (1)
 #define IRQ_RESERVED    (-1)
--- a/xen/include/xen/irq.h
+++ b/xen/include/xen/irq.h
@@ -84,6 +84,8 @@ typedef struct irq_desc {
     struct list_head rl_link;
 } __cacheline_aligned irq_desc_t;
 
+#define irq_to_desc(irq)    (&irq_desc[irq])
+
 int init_one_irq_desc(struct irq_desc *);
 int arch_init_one_irq_desc(struct irq_desc *);