From a1dafe857db56c35878c71560089a4694ac841fd Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 7 Jan 2015 15:31:28 +0800 Subject: [PATCH] iommu, x86: Restructure setup of the irq remapping feature enable_IR_x2apic() calls setup_irq_remapping_ops() which by default installs the intel dmar remapping ops and then calls the amd iommu irq remapping prepare callback to figure out whether we are running on an AMD machine with irq remapping hardware. Right after that it calls irq_remapping_prepare() which pointlessly checks: if (!remap_ops || !remap_ops->prepare) return -ENODEV; and then calls remap_ops->prepare() which is silly in the AMD case as it got called from setup_irq_remapping_ops() already a few microseconds ago. Simplify this and just collapse everything into irq_remapping_prepare(). The irq_remapping_prepare() remains still silly as it assigns blindly the intel ops, but that's not scope of this patch. The scope here is to move the preperatory work, i.e. memory allocations out of the atomic section which is required to enable irq remapping. Signed-off-by: Thomas Gleixner Tested-by: Borislav Petkov Acked-and-tested-by: Joerg Roedel Cc: Tony Luck Cc: iommu@lists.linux-foundation.org Cc: Joerg Roedel Cc: H. Peter Anvin Cc: Benjamin Herrenschmidt Cc: Yinghai Lu Cc: David Rientjes Cc: HATAYAMA Daisuke Cc: Jan Beulich Cc: Richard Weinberger Cc: Oren Twaig Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20141205084147.232633738@linutronix.de Link: http://lkml.kernel.org/r/1420615903-28253-2-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Jiang Liu Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/irq_remapping.h | 2 -- arch/x86/kernel/apic/apic.c | 3 --- drivers/iommu/irq_remapping.c | 19 +++++++------------ 3 files changed, 7 insertions(+), 17 deletions(-) diff --git a/arch/x86/include/asm/irq_remapping.h b/arch/x86/include/asm/irq_remapping.h index b7747c4c2cf2..f1b619e5a50d 100644 --- a/arch/x86/include/asm/irq_remapping.h +++ b/arch/x86/include/asm/irq_remapping.h @@ -33,7 +33,6 @@ struct irq_cfg; #ifdef CONFIG_IRQ_REMAP -extern void setup_irq_remapping_ops(void); extern int irq_remapping_supported(void); extern void set_irq_remapping_broken(void); extern int irq_remapping_prepare(void); @@ -60,7 +59,6 @@ void irq_remap_modify_chip_defaults(struct irq_chip *chip); #else /* CONFIG_IRQ_REMAP */ -static inline void setup_irq_remapping_ops(void) { } static inline int irq_remapping_supported(void) { return 0; } static inline void set_irq_remapping_broken(void) { } static inline int irq_remapping_prepare(void) { return -ENODEV; } diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 29b5b18afa27..141f1031013d 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1597,9 +1597,6 @@ void __init enable_IR_x2apic(void) int ret, x2apic_enabled = 0; int hardware_init_ret; - /* Make sure irq_remap_ops are initialized */ - setup_irq_remapping_ops(); - hardware_init_ret = irq_remapping_prepare(); if (hardware_init_ret && !x2apic_supported()) return; diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c index 89c4846683be..91d5884d3ed9 100644 --- a/drivers/iommu/irq_remapping.c +++ b/drivers/iommu/irq_remapping.c @@ -194,16 +194,6 @@ static __init int setup_irqremap(char *str) } early_param("intremap", setup_irqremap); -void __init setup_irq_remapping_ops(void) -{ - remap_ops = &intel_irq_remap_ops; - -#ifdef CONFIG_AMD_IOMMU - if (amd_iommu_irq_ops.prepare() == 0) - remap_ops = &amd_iommu_irq_ops; -#endif -} - void set_irq_remapping_broken(void) { irq_remap_broken = 1; @@ -222,9 +212,14 @@ int irq_remapping_supported(void) int __init irq_remapping_prepare(void) { - if (!remap_ops || !remap_ops->prepare) - return -ENODEV; + remap_ops = &intel_irq_remap_ops; +#ifdef CONFIG_AMD_IOMMU + if (amd_iommu_irq_ops.prepare() == 0) { + remap_ops = &amd_iommu_irq_ops; + return 0; + } +#endif return remap_ops->prepare(); } -- 2.30.2