Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751579AbWEIItw (ORCPT ); Tue, 9 May 2006 04:49:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751609AbWEIItb (ORCPT ); Tue, 9 May 2006 04:49:31 -0400 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:46723 "EHLO sous-sol.org") by vger.kernel.org with ESMTP id S1751547AbWEIItD (ORCPT ); Tue, 9 May 2006 04:49:03 -0400 Message-Id: <20060509085157.070289000@sous-sol.org> References: <20060509084945.373541000@sous-sol.org> Date: Tue, 09 May 2006 00:00:23 -0700 From: Chris Wright To: linux-kernel@vger.kernel.org Cc: virtualization@lists.osdl.org, xen-devel@lists.xensource.com, Ian Pratt , Christian Limpach Subject: [RFC PATCH 23/35] Increase x86 interrupt vector range Content-Disposition: inline; filename=x86-increase-interrupt-vector-range Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3546 Lines: 112 Remove the limit of 256 interrupt vectors by changing the value stored in orig_{e,r}ax to be the negated interrupt vector. The orig_{e,r}ax needs to be < 0 to allow the signal code to distinguish between return from interrupt and return from syscall. With this change applied, NR_IRQS can be > 256. Xen extends the IRQ numbering space to include room for dynamically allocated virtual interrupts (in the range 256-511), which requires a more permissive interface to do_IRQ. Signed-off-by: Ian Pratt Signed-off-by: Christian Limpach Signed-off-by: Chris Wright --- arch/i386/kernel/entry.S | 4 ++-- arch/i386/kernel/irq.c | 4 ++-- arch/x86_64/kernel/entry.S | 2 +- arch/x86_64/kernel/irq.c | 4 ++-- arch/x86_64/kernel/smp.c | 4 ++-- include/asm-x86_64/hw_irq.h | 2 +- 6 files changed, 10 insertions(+), 10 deletions(-) --- linus-2.6.orig/arch/i386/kernel/entry.S +++ linus-2.6/arch/i386/kernel/entry.S @@ -464,7 +464,7 @@ vector=0 ENTRY(irq_entries_start) .rept NR_IRQS ALIGN -1: pushl $vector-256 +1: pushl $~(vector) jmp common_interrupt .data .long 1b @@ -481,7 +481,7 @@ common_interrupt: #define BUILD_INTERRUPT(name, nr) \ ENTRY(name) \ - pushl $nr-256; \ + pushl $~(nr); \ SAVE_ALL \ movl %esp,%eax; \ call smp_/**/name; \ --- linus-2.6.orig/arch/i386/kernel/irq.c +++ linus-2.6/arch/i386/kernel/irq.c @@ -53,8 +53,8 @@ static union irq_ctx *softirq_ctx[NR_CPU */ fastcall unsigned int do_IRQ(struct pt_regs *regs) { - /* high bits used in ret_from_ code */ - int irq = regs->orig_eax & 0xff; + /* high bit used in ret_from_ code */ + int irq = ~regs->orig_eax; #ifdef CONFIG_4KSTACKS union irq_ctx *curctx, *irqctx; u32 *isp; --- linus-2.6.orig/arch/x86_64/kernel/entry.S +++ linus-2.6/arch/x86_64/kernel/entry.S @@ -601,7 +601,7 @@ retint_kernel: */ .macro apicinterrupt num,func INTR_FRAME - pushq $\num-256 + pushq $~(\num) CFI_ADJUST_CFA_OFFSET 8 interrupt \func jmp ret_from_intr --- linus-2.6.orig/arch/x86_64/kernel/irq.c +++ linus-2.6/arch/x86_64/kernel/irq.c @@ -91,8 +91,8 @@ skip: */ asmlinkage unsigned int do_IRQ(struct pt_regs *regs) { - /* high bits used in ret_from_ code */ - unsigned irq = regs->orig_rax & 0xff; + /* high bit used in ret_from_ code */ + unsigned irq = ~regs->orig_rax; exit_idle(); irq_enter(); --- linus-2.6.orig/arch/x86_64/kernel/smp.c +++ linus-2.6/arch/x86_64/kernel/smp.c @@ -135,10 +135,10 @@ asmlinkage void smp_invalidate_interrupt cpu = smp_processor_id(); /* - * orig_rax contains the interrupt vector - 256. + * orig_rax contains the negated interrupt vector. * Use that to determine where the sender put the data. */ - sender = regs->orig_rax + 256 - INVALIDATE_TLB_VECTOR_START; + sender = ~regs->orig_rax - INVALIDATE_TLB_VECTOR_START; f = &per_cpu(flush_state, sender); if (!cpu_isset(cpu, f->flush_cpumask)) --- linus-2.6.orig/include/asm-x86_64/hw_irq.h +++ linus-2.6/include/asm-x86_64/hw_irq.h @@ -127,7 +127,7 @@ asmlinkage void IRQ_NAME(nr); \ __asm__( \ "\n.p2align\n" \ "IRQ" #nr "_interrupt:\n\t" \ - "push $" #nr "-256 ; " \ + "push $~(" #nr ") ; " \ "jmp common_interrupt"); #if defined(CONFIG_X86_IO_APIC) -- - 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/