From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755118Ab0ASUWR (ORCPT ); Tue, 19 Jan 2010 15:22:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751559Ab0ASUWQ (ORCPT ); Tue, 19 Jan 2010 15:22:16 -0500 Received: from mga01.intel.com ([192.55.52.88]:39432 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751240Ab0ASUWP (ORCPT ); Tue, 19 Jan 2010 15:22:15 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.49,305,1262592000"; d="scan'208";a="532637172" Subject: [patch] x86, irq: don't block IRQ0_VECTOR..IRQ15_VECTOR's on all cpu's From: Suresh Siddha Reply-To: Suresh Siddha To: "H.PeterA" , Ingo Molnar , Thomas Gleixner , Yinghai Lu , "Eric W. Biederman" Cc: LKML Content-Type: text/plain Organization: Intel Corp Date: Tue, 19 Jan 2010 12:20:53 -0800 Message-Id: <1263932453.2814.52.camel@sbs-t61.sc.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 (2.26.3-1.fc11) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently IRQ0..IRQ15 are assigned to IRQ0_VECTOR..IRQ15_VECTOR's on all the cpu's. If these IRQ's are handled by legacy pic controller, then the kernel handles them only on cpu 0. So there is no need to block this vector space on all cpu's. Similarly if these IRQ's are handled by IO-APIC, then the irq affinity will determine on which cpu's we need allocate the vector resource for that particular IRQ. This can be done dynamically and here also there is no need to block 16 vectors for IRQ0..IRQ15 on all cpu's. Fix this by initially assigning IRQ0..IRQ15 to IRQ0_VECTOR..IRQ15_VECTOR's only on cpu 0. If the legacy controllers like pic handles these irq's, then this configuration will be fixed. If more modern controllers like IO-APIC handle these IRQ's, then we start with this configuration and as IRQ's migrate, vectors (/and cpu's) associated with these IRQ's change dynamically. This will freeup the block of 16 vectors on other cpu's which don't handle IRQ0..IRQ15, which can now be used for other IRQ's that the particular cpu handle. Signed-off-by: Suresh Siddha --- arch/x86/include/asm/irq.h | 1 + arch/x86/kernel/apic/io_apic.c | 33 ++++++++++----------------------- arch/x86/kernel/irqinit.c | 35 +++++++++++++++++------------------ arch/x86/kernel/vmiclock_32.c | 2 ++ 4 files changed, 30 insertions(+), 41 deletions(-) Index: tip/arch/x86/kernel/apic/io_apic.c =================================================================== --- tip.orig/arch/x86/kernel/apic/io_apic.c +++ tip/arch/x86/kernel/apic/io_apic.c @@ -94,8 +94,6 @@ struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCE /* # of MP IRQ source entries */ int mp_irq_entries; -/* Number of legacy interrupts */ -static int nr_legacy_irqs __read_mostly = NR_IRQS_LEGACY; /* GSI interrupts */ static int nr_irqs_gsi = NR_IRQS_LEGACY; @@ -140,27 +138,10 @@ static struct irq_pin_list *get_one_free /* irq_cfg is indexed by the sum of all RTEs in all I/O APICs. */ #ifdef CONFIG_SPARSE_IRQ -static struct irq_cfg irq_cfgx[] = { +static struct irq_cfg irq_cfgx[NR_LEGACY_IRQS]; #else -static struct irq_cfg irq_cfgx[NR_IRQS] = { +static struct irq_cfg irq_cfgx[NR_IRQS]; #endif - [0] = { .vector = IRQ0_VECTOR, }, - [1] = { .vector = IRQ1_VECTOR, }, - [2] = { .vector = IRQ2_VECTOR, }, - [3] = { .vector = IRQ3_VECTOR, }, - [4] = { .vector = IRQ4_VECTOR, }, - [5] = { .vector = IRQ5_VECTOR, }, - [6] = { .vector = IRQ6_VECTOR, }, - [7] = { .vector = IRQ7_VECTOR, }, - [8] = { .vector = IRQ8_VECTOR, }, - [9] = { .vector = IRQ9_VECTOR, }, - [10] = { .vector = IRQ10_VECTOR, }, - [11] = { .vector = IRQ11_VECTOR, }, - [12] = { .vector = IRQ12_VECTOR, }, - [13] = { .vector = IRQ13_VECTOR, }, - [14] = { .vector = IRQ14_VECTOR, }, - [15] = { .vector = IRQ15_VECTOR, }, -}; void __init io_apic_disable_legacy(void) { @@ -185,8 +166,14 @@ int __init arch_early_irq_init(void) desc->chip_data = &cfg[i]; zalloc_cpumask_var_node(&cfg[i].domain, GFP_NOWAIT, node); zalloc_cpumask_var_node(&cfg[i].old_domain, GFP_NOWAIT, node); - if (i < nr_legacy_irqs) - cpumask_setall(cfg[i].domain); + /* + * For legacy IRQ's, start with assigning irq0 to irq15 to + * IRQ0_VECTOR to IRQ15_VECTOR on cpu 0. + */ + if (i < nr_legacy_irqs) { + cfg[i].vector = IRQ0_VECTOR + i; + cpumask_set_cpu(0, cfg[i].domain); + } } return 0; Index: tip/arch/x86/kernel/irqinit.c =================================================================== --- tip.orig/arch/x86/kernel/irqinit.c +++ tip/arch/x86/kernel/irqinit.c @@ -84,24 +84,7 @@ static struct irqaction irq2 = { }; DEFINE_PER_CPU(vector_irq_t, vector_irq) = { - [0 ... IRQ0_VECTOR - 1] = -1, - [IRQ0_VECTOR] = 0, - [IRQ1_VECTOR] = 1, - [IRQ2_VECTOR] = 2, - [IRQ3_VECTOR] = 3, - [IRQ4_VECTOR] = 4, - [IRQ5_VECTOR] = 5, - [IRQ6_VECTOR] = 6, - [IRQ7_VECTOR] = 7, - [IRQ8_VECTOR] = 8, - [IRQ9_VECTOR] = 9, - [IRQ10_VECTOR] = 10, - [IRQ11_VECTOR] = 11, - [IRQ12_VECTOR] = 12, - [IRQ13_VECTOR] = 13, - [IRQ14_VECTOR] = 14, - [IRQ15_VECTOR] = 15, - [IRQ15_VECTOR + 1 ... NR_VECTORS - 1] = -1 + [0 ... NR_VECTORS - 1] = -1, }; int vector_used_by_percpu_irq(unsigned int vector) @@ -116,6 +99,9 @@ int vector_used_by_percpu_irq(unsigned i return 0; } +/* Number of legacy interrupts */ +int nr_legacy_irqs __read_mostly = NR_IRQS_LEGACY; + void __init init_ISA_irqs(void) { int i; @@ -142,6 +128,19 @@ void __init init_ISA_irqs(void) void __init init_IRQ(void) { + int i; + + /* + * On cpu 0, Assign IRQ0_VECTOR..IRQ15_VECTOR's to IRQ 0..15. + * If these IRQ's are handled by legacy interrupt-controllers like PIC, + * then this configuration will likely be static after the boot. If + * these IRQ's are handled by more mordern controllers like IO-APIC, + * then this vector space can be freed and re-used dynamically as the + * irq's migrate etc. + */ + for (i = 0; i < nr_legacy_irqs; i++) + per_cpu(vector_irq, 0)[IRQ0_VECTOR + i] = i; + x86_init.irqs.intr_init(); } Index: tip/arch/x86/kernel/vmiclock_32.c =================================================================== --- tip.orig/arch/x86/kernel/vmiclock_32.c +++ tip/arch/x86/kernel/vmiclock_32.c @@ -235,6 +235,8 @@ void __init vmi_time_init(void) vmi_time_init_clockevent(); setup_irq(0, &vmi_clock_action); + for_each_possible_cpu(cpu) + per_cpu(vector_irq, cpu)[vmi_get_timer_vector()] = 0; } #ifdef CONFIG_X86_LOCAL_APIC Index: tip/arch/x86/include/asm/irq.h =================================================================== --- tip.orig/arch/x86/include/asm/irq.h +++ tip/arch/x86/include/asm/irq.h @@ -48,5 +48,6 @@ extern DECLARE_BITMAP(used_vectors, NR_V extern int vector_used_by_percpu_irq(unsigned int vector); extern void init_ISA_irqs(void); +extern int nr_legacy_irqs; #endif /* _ASM_X86_IRQ_H */