When converting x86 to new hierarchy irqdoamin framework, Thomas noticed that the interrupt remapping initialization flow is a little complex and has troubles in memory allocation. Then there is a joint force to simplify IR initialization flow, please refer to related threads at: https://lkml.org/lkml/2014/12/5/114 https://lkml.org/lkml/2014/12/10/20 https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg788792.html
This patch set is based on latest mainstream kernel and I will rebased it onto v3.19-rc1 once v3.19-rc1 is out. And you may access it at: https://github.com/jiangliu/linux.git ir_init_v1 This patch set combimes above three patches to simplify IR initalization flow and solves memory allocation issues. While at it, this patch set also refines CPU X2APIC initialization code for maintenance. It also fixes two bugs related to X2APIC support. 1) System hangs or panics if BIOS enables CPU X2APIC mode but kernel doesn't support X2APIC. 2) System livelocks if BIOS enables CPU X2APIC but opt-outs IR X2APIC. This patch set has been tested with on an Intel 4-socket system with following configuration: --------------------------------------------------------------------------- [CPU X2APIC] [IR X2APIC] [Linux IR] [Linux X2APIC] [Result] 1 D / D D OK 2 D / E D OK 3 D / E E OK 4 P / E E OK 5 P / D D Panic(expected) 6 P / E D Panic(expected) 7 P H E E OK ---------------------------------------------------------------------------- CPU X2APIC: whether CPU X2APIC is enabled by hardware and BIOS IR X2APIC: whether interrupt remapping hardware supports X2APIC mode Linux IR: whether interrupt remapping is enabled by Linux kernel Linux X2APIC: whether X2APIC is supported by Linux kernel D: disabled E: enabled /: Not care P: CPU X2APIC pre-enabled by BIOS H: Hard-coded to opt-out X2APIC support in interrupt remapping hardware The patch set changes the behevior of the last three rows: 1) Row 5 and 6 panics with clear messages instead of random hang or panic. 2) Row 7 boots successfully instead of livelocking. The patch set also passes Fengguang's 0day test suites. Due to lack of hardware platforms for tests, tests on AMD platform are welcomed! Jiang Liu (11): x86/apic: Panic if kernel doesn't support x2apic but BIOS has enabled x2apic x86/apic: Kill useless variable x2apic_enabled in function enable_IR_x2apic() x86/apic: Correctly detect X2APIC status in function enable_IR() x86/apic: Refine enable_IR_x2apic() and related functions iommu/vt-d: Prepare for killing function irq_remapping_supported() iommu/vt-d: Allow IR works in XAPIC mode though CPU works in X2APIC mode x86/apic: Only disable CPU x2apic mode when necessary iommu/irq_remapping: Kill function irq_remapping_supported() and related code iommu/irq_remapping: Refine function irq_remapping_prepare() for maintenance iommu/irq_remapping: Change variable disable_irq_remap to be static iommu/irq_remapping: Normailize the way to detect whether IR is enabled Joerg Roedel (2): iommu/vt-d: Allocate IRQ remapping data structures only for all IOMMUs iommu/amd: Check for irq-remap support amd_iommu_prepare() Thomas Gleixner (4): x86, smpboot: Remove pointless preempt_disable() in native_smp_prepare_cpus() iommu, x86: Restructure setup of the irq remapping feature iommu/vt-d: Move iommu preparatory allocations to irq_remap_ops.prepare iommu/vt-d: Convert allocations to GFP_KERNEL arch/x86/include/asm/irq_remapping.h | 4 -- arch/x86/kernel/apic/apic.c | 104 ++++++++++++++++------------------ arch/x86/kernel/smpboot.c | 8 +-- drivers/iommu/amd_iommu.c | 1 - drivers/iommu/amd_iommu_init.c | 10 +--- drivers/iommu/amd_iommu_proto.h | 1 - drivers/iommu/intel_irq_remapping.c | 96 ++++++++++++++++--------------- drivers/iommu/irq_remapping.c | 74 ++++++++---------------- drivers/iommu/irq_remapping.h | 5 -- 9 files changed, 129 insertions(+), 174 deletions(-) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
