Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753865Ab0ADUIi (ORCPT ); Mon, 4 Jan 2010 15:08:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752581Ab0ADUIf (ORCPT ); Mon, 4 Jan 2010 15:08:35 -0500 Received: from hera.kernel.org ([140.211.167.34]:53105 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752801Ab0ADUIe (ORCPT ); Mon, 4 Jan 2010 15:08:34 -0500 Message-ID: <4B424A5C.7080309@kernel.org> Date: Mon, 04 Jan 2010 12:06:52 -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> In-Reply-To: <4B4245FC.7070902@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: 2389 Lines: 72 On 01/04/2010 11:48 AM, H. Peter Anvin wrote: > [Adding Suresh to the Cc: list] > > On 01/04/2010 11:35 AM, Yinghai Lu wrote: >> >> so we can use [0x10, 0x1f] >> >> sth like this? >> > > No!!! > > [0x10, 0x1f] is reserved for exceptions. We can probably get away with > stealing *one* vector... presumably at the end (0x1f). However, we can > absolutely not use the whole block: 0x10-0x13 is occupied by exceptions > we already have OS support for (#MF, #AC, #MC, and #XM), and it's pretty > much guaranteed we'll have more coming. However, growth is quite slow > and since this is a kernel-internal vector (not accessible to user > space) it is not creating an API. > > In other words, we could change FIRST_EXTERNAL_VECTOR to 0x1f, and use > it for IRQ_MOVE_CLEANUP_VECTOR. Then use 0x20..0x2f for the legacy vectors. > Subject: [PATCH 1/2] x86: get back 16 vectors -v2: according to hpa that we could start from 0x1f Signed-off-by: Yinghai Lu --- arch/x86/include/asm/irq_vectors.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 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 +30,9 @@ /* * IDT vectors usable for external interrupt sources start * at 0x20: + * hpa said we can start from 0x1f */ -#define FIRST_EXTERNAL_VECTOR 0x20 +#define FIRST_EXTERNAL_VECTOR 0x1f #ifdef CONFIG_X86_32 # define SYSCALL_VECTOR 0x80 @@ -41,15 +42,15 @@ #endif /* - * Reserve the lowest usable priority level 0x20 - 0x2f for triggering + * Reserve the lowest usable priority level 0x1f for triggering * cleanup after irq migration. */ #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) -- 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/