diff options
| author | Ingo Molnar <mingo@elte.hu> | 2009-01-31 02:56:44 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-31 04:21:25 +0100 |
| commit | 009eb3fe146aa6f1951f3c5235851bb8d1330dfb (patch) | |
| tree | 6b2cba03c7ab3d3f067729d0e62b7674ba1c3907 /arch/x86/include/asm/irq_vectors.h | |
| parent | c379698fdac7cb65c96dec549850ce606dd6ceba (diff) | |
x86, irq: describe NR_IRQ sizing details, clean up
Impact: cleanup
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/include/asm/irq_vectors.h')
| -rw-r--r-- | arch/x86/include/asm/irq_vectors.h | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h index ec87910025d..41e2450e13b 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -126,23 +126,37 @@ #define LAST_VM86_IRQ 15 #define invalid_vm86_irq(irq) ((irq) < 3 || (irq) > 15) +/* + * Size the maximum number of interrupts. + * + * If the irq_desc[] array has a sparse layout, we can size things + * generously - it scales up linearly with the maximum number of CPUs, + * and the maximum number of IO-APICs, whichever is higher. + * + * In other cases we size more conservatively, to not create too large + * static arrays. + */ + #define NR_IRQS_LEGACY 16 +#define CPU_VECTOR_LIMIT ( 8 * NR_CPUS ) +#define IO_APIC_VECTOR_LIMIT ( 32 * MAX_IO_APICS ) + #ifdef CONFIG_X86_IO_APIC -# ifndef CONFIG_SPARSE_IRQ +# ifdef CONFIG_SPARSE_IRQ +# define NR_IRQS \ + (CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ? \ + (NR_VECTORS + CPU_VECTOR_LIMIT) : \ + (NR_VECTORS + IO_APIC_VECTOR_LIMIT)) +# else # if NR_CPUS < MAX_IO_APICS -# define NR_IRQS (NR_VECTORS + (32 * NR_CPUS)) +# define NR_IRQS (NR_VECTORS + 4*CPU_VECTOR_LIMIT) # else -# define NR_IRQS (NR_VECTORS + (32 * MAX_IO_APICS)) +# define NR_IRQS (NR_VECTORS + IO_APIC_VECTOR_LIMIT) # endif -# else -# define NR_IRQS \ - ((8 * NR_CPUS) > (32 * MAX_IO_APICS) ? \ - (NR_VECTORS + (8 * NR_CPUS)) : \ - (NR_VECTORS + (32 * MAX_IO_APICS))) # endif #else /* !CONFIG_X86_IO_APIC: */ -# define NR_IRQS 16 +# define NR_IRQS NR_IRQS_LEGACY #endif #endif /* _ASM_X86_IRQ_VECTORS_H */ |