[Patch Part2 v5 27/33] x86/irq: Refine the way to calculate NR_IRQS

From: Jiang Liu
Date: Mon Apr 13 2015 - 22:35:23 EST


Now we have made MSI independent of IOAPIC, so we need to refine the
way to calculate NR_IRQS to support configuration with MSI enabled but
IOAPIC disabled.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Jan Beulich <JBeulich@xxxxxxxx>
Link: http://lkml.kernel.org/r/1416901802-24211-36-git-send-email-jiang.liu@xxxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Joerg Roedel <jroedel@xxxxxxx>
---
arch/x86/include/asm/irq_vectors.h | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 666c89ec4bd7..b26cb124a4f1 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -155,18 +155,22 @@ static inline int invalid_vm86_irq(int irq)
* static arrays.
*/

-#define NR_IRQS_LEGACY 16
+#define NR_IRQS_LEGACY 16

-#define IO_APIC_VECTOR_LIMIT ( 32 * MAX_IO_APICS )
+#define CPU_VECTOR_LIMIT (64 * NR_CPUS)
+#define IO_APIC_VECTOR_LIMIT (32 * MAX_IO_APICS)

-#ifdef CONFIG_X86_IO_APIC
-# define CPU_VECTOR_LIMIT (64 * NR_CPUS)
-# define NR_IRQS \
+#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_PCI_MSI)
+#define NR_IRQS \
(CPU_VECTOR_LIMIT > IO_APIC_VECTOR_LIMIT ? \
(NR_VECTORS + CPU_VECTOR_LIMIT) : \
(NR_VECTORS + IO_APIC_VECTOR_LIMIT))
-#else /* !CONFIG_X86_IO_APIC: */
-# define NR_IRQS NR_IRQS_LEGACY
+#elif defined(CONFIG_X86_IO_APIC)
+#define NR_IRQS (NR_VECTORS + IO_APIC_VECTOR_LIMIT)
+#elif defined(CONFIG_PCI_MSI)
+#define NR_IRQS (NR_VECTORS + CPU_VECTOR_LIMIT)
+#else
+#define NR_IRQS NR_IRQS_LEGACY
#endif

#endif /* _ASM_X86_IRQ_VECTORS_H */
--
1.7.10.4

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