irq: initialize nr_irqs based on nr_cpu_ids
Impact: Reduce memory usage.
This is the second half of the changes to make the irq_desc_ptrs be
variable sized based on nr_cpu_ids. This is done by adding a new
"max_nr_irqs" macro to irq_vectors.h (and a dummy in irqnr.h) to
return a max NR_IRQS value based on NR_CPUS or nr_cpu_ids.
This necessitated moving the define of MAX_IO_APICS to a separate
file (asm/apicnum.h) so it could be included without the baggage
of the other asm/apicdef.h declarations.
Signed-off-by: Mike Travis <travis@sgi.com>
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index f7ff650..602361a 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -105,6 +105,8 @@
#if defined(CONFIG_X86_IO_APIC) && !defined(CONFIG_X86_VOYAGER)
+#include <asm/apicnum.h> /* need MAX_IO_APICS */
+
#ifndef CONFIG_SPARSE_IRQ
# if NR_CPUS < MAX_IO_APICS
# define NR_IRQS (NR_VECTORS + (32 * NR_CPUS))
@@ -112,11 +114,15 @@
# define NR_IRQS (NR_VECTORS + (32 * MAX_IO_APICS))
# endif
#else
-# if (8 * NR_CPUS) > (32 * MAX_IO_APICS)
-# define NR_IRQS (NR_VECTORS + (8 * NR_CPUS))
-# else
-# define NR_IRQS (NR_VECTORS + (32 * MAX_IO_APICS))
-# endif
+
+/* defined as a macro so nr_irqs = max_nr_irqs(nr_cpu_ids) can be used */
+# define max_nr_irqs(nr_cpus) \
+ ((8 * nr_cpus) > (32 * MAX_IO_APICS) ? \
+ (NR_VECTORS + (8 * NR_CPUS)) : \
+ (NR_VECTORS + (32 * MAX_IO_APICS))) \
+
+# define NR_IRQS max_nr_irqs(NR_CPUS)
+
#endif
#elif defined(CONFIG_X86_VOYAGER)