Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753552Ab0ADVWO (ORCPT ); Mon, 4 Jan 2010 16:22:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751883Ab0ADVWM (ORCPT ); Mon, 4 Jan 2010 16:22:12 -0500 Received: from hera.kernel.org ([140.211.167.34]:37584 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750770Ab0ADVWK (ORCPT ); Mon, 4 Jan 2010 16:22:10 -0500 Message-ID: <4B425BB7.90501@kernel.org> Date: Mon, 04 Jan 2010 13:20:55 -0800 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091130 SUSE/3.0.0-1.1.1 Thunderbird/3.0 MIME-Version: 1.0 To: "H. Peter Anvin" CC: "Eric W. Biederman" , Jesse Brandeburg , Ingo Molnar , Thomas Gleixner , "linux-kernel@vger.kernel.org" , Andrew Morton , NetDEV list , Jesse Brandeburg , Suresh Siddha Subject: Re: Subject: [PATCH 1/2] x86: get back 15 vectors References: <4B347AEE.6030705@kernel.org> <20091228094707.GH24690@elte.hu> <4B398ECD.1080506@kernel.org> <4807377b1001031906s6b1ee576jc021da2642bb4147@mail.gmail.com> <4B415E73.1050801@kernel.org> <4B419113.1090204@kernel.org> <4B423B08.3010005@zytor.com> <4B424305.7050803@kernel.org> <4B4245FC.7070902@zytor.com> <4B424A5C.7080309@kernel.org> <4B425085.5040103@kernel.org> <4B42595E.9010404@zytor.com> In-Reply-To: <4B42595E.9010404@zytor.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3695 Lines: 101 On 01/04/2010 01:10 PM, H. Peter Anvin wrote: > * 0x1f is documented as reserved. However, the ability for the APIC > * to generate vectors starting at 0x10 is documented, as is the > * ability for the CPU to receive any vector number as an interrupt. > * 0x1f is used for IRQ_MOVE_CLEANUP_VECTOR since that vector needs > * an entire privilege level (16 vectors) all by itself at a higher > * priority than any actual device vector. Thus, by placing it in the > * otherwise-unusable 0x10 privilege level, we avoid wasting a full > * 16-vector block. Subject: [PATCH 1/2] x86: get back 16 vectors -v2: according to hpa that we could start from 0x1f -v3: update comments from Eric -v4: update comments from hpa Signed-off-by: Yinghai Lu --- arch/x86/include/asm/irq_vectors.h | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) Index: linux-2.6/arch/x86/include/asm/irq_vectors.h =================================================================== --- linux-2.6.orig/arch/x86/include/asm/irq_vectors.h +++ linux-2.6/arch/x86/include/asm/irq_vectors.h @@ -30,8 +30,17 @@ /* * IDT vectors usable for external interrupt sources start * at 0x20: + * hpa said we can start from 0x1f. + * 0x1f is documented as reserved. However, the ability for the APIC + * to generate vectors starting at 0x10 is documented, as is the + * ability for the CPU to receive any vector number as an interrupt. + * 0x1f is used for IRQ_MOVE_CLEANUP_VECTOR since that vector needs + * an entire privilege level (16 vectors) all by itself at a higher + * priority than any actual device vector. Thus, by placing it in the + * otherwise-unusable 0x10 privilege level, we avoid wasting a full + * 16-vector block. */ -#define FIRST_EXTERNAL_VECTOR 0x20 +#define FIRST_EXTERNAL_VECTOR 0x1f #ifdef CONFIG_X86_32 # define SYSCALL_VECTOR 0x80 @@ -41,15 +50,19 @@ #endif /* - * Reserve the lowest usable priority level 0x20 - 0x2f for triggering + * Reserve the lowest usable priority level 0x10 - 0x1f for triggering * cleanup after irq migration. + * this overlaps with the reserved range for cpu exceptions so this + * will need to be changed to 0x20 - 0x2f if the last cpu exception is + * ever allocated. */ + #define IRQ_MOVE_CLEANUP_VECTOR FIRST_EXTERNAL_VECTOR /* - * Vectors 0x30-0x3f are used for ISA interrupts. + * Vectors 0x20-0x2f are used for ISA interrupts. */ -#define IRQ0_VECTOR (FIRST_EXTERNAL_VECTOR + 0x10) +#define IRQ0_VECTOR (FIRST_EXTERNAL_VECTOR + 1) #define IRQ1_VECTOR (IRQ0_VECTOR + 1) #define IRQ2_VECTOR (IRQ0_VECTOR + 2) @@ -68,6 +81,13 @@ #define IRQ15_VECTOR (IRQ0_VECTOR + 15) /* + * First APIC vector available to drivers: (vectors 0x30-0xee) we + * start at 0x31 to spread out vectors evenly between priority + * levels. (0x80 is the syscall vector) + */ +#define FIRST_DEVICE_VECTOR (IRQ15_VECTOR + 2) + +/* * Special IRQ vectors used by the SMP architecture, 0xf0-0xff * * some of the following vectors are 'rare', they are merged @@ -120,13 +140,6 @@ */ #define MCE_SELF_VECTOR 0xeb -/* - * First APIC vector available to drivers: (vectors 0x30-0xee) we - * start at 0x31(0x41) to spread out vectors evenly between priority - * levels. (0x80 is the syscall vector) - */ -#define FIRST_DEVICE_VECTOR (IRQ15_VECTOR + 2) - #define NR_VECTORS 256 #define FPU_IRQ 13 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/